EPA-600/R-26-147
December 1S96
ACTIVE SOIL DEPRESSURIZATION (ASD) DEMONSTRATION
IN A LARGE BUILDING
By
Ashely D. Williamson
Bobby E. Pyle
Susan E. McDonough
Charles S. Fowler
Southern Research Institute-
Post Office Box 55305
Birmingham, Alabama 35255-5305
EPA Contract No. 68D20062
Work Assignment 2/037
SRJ Project 7722.2.37
EPA Project Officer: Marc Y. Menetrez
National Risk Management Research Laboratory
Research Triangle Park. North Carolina 27711
Prepared for:
U.S.Environmental Protection Agency
Office of Research and Development
Washington, DC 20460
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before comp
(.REPORT NO. 2.
E PA - 600/R-96-147
4. TITLE AND SUBTITLE
Active Soil Depressurization (ASD) Demonstration
in a Large Building
5. REPORT DATE
December 1996
6. PERFORMING ORGANIZATION CODE
7.AUTHOR(S) Ashley D. Williamson, Bobby E. Pyle, Susan
E. McDonough, and Charles S. Fowler
8. PERFORMING ORGANIZATION REPORT NO.
SRI-ENV-94-849-7722.1.37
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Southern Research Institute
P.O. Box 55305
Birmingham, Alabama 35255-5305
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-D2-0062, W.A. 2/037
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air Pollution Prevention and Control Division
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final; 4/93 - 11/95
14. SPONSORING AGENCY CODE
EPA/600/13
15. supplementary notesAPPCD project 0fficer is Marc Y. Menetrez, Mail Drop 54, 919/
541-7981.
i6.abstract repQrt gives results of an evaluation of the feasibility of implementing
radon resistant construction techniques--especially active soil depressurization
(ASD)--in new large buildings in Florida. Indoor radon concentrations and radon
entry were monitored in a finished building with the heating, ventilation, and air-
conditioning (HVAC) system on paid the ASD system off, and with the ASD systems
activated in a temporary mode. Results from the study have demonstrated that, with
sufficient attention to building design and construction, significant radon entry into a
large building constructed on a site of high radon potential can be prevented. The
effectiveness of the ASD system as a radon mitigation technique could not be realis-
tically evaluated due to a lack of radon in the building. However, pressure field
extension (PFE) measurements suggest that the design is more than adequate to meet
its purpose of pressure reversal between the building interior and the subslab re-
gions.
17. KFY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
Radon
Buildings
Soils
Construction
Pollution Control
Stationary Sources
Active Soil Depressuri-
zation
Depressurization
13 B
07B
13 M
08M
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
-------
NOTICE
This document has been reviewed in accordance with
U.S. Environmental Protection Agency policy and
approved for publication. Mention of trade names
or commercial products does not constitute endorse-
ment or recommendation for use.
-------
FOREWORD
The U.S. Environmental Protection Agency is charged by Congress with pro-
tecting the Nation's land, air, and water resources. Under a mandate of national
environmental laws, the Agency strives to formulate and implement actions lead-
ing to a compatible balance between human activities and the ability of natural
systems to support and nurture life. To meet this mandate, EPA's research
program is providing data and technical support for solving environmental pro-
blems today and building a science knowledge base necessary to manage our eco-
logical resources wisely, understand how pollutants affect our health, and pre-
vent or reduce environmental risks in the future.
The National Risk Management Research Laboratory is the Agency's center for
investigation of technological and management approaches for reducing risks
from threats to human health ajid the environment. The focus of the Laboratory's
research program is on methods for the prevention and control of pollution to air,
land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites and groundwater; and prevention and
control of indoor air pollution. The goal of this research effort is to catalyze
development and implementation of innovative, cost-effective environmental
technologies; develop scientific and engineering information needed by EPA to
support regulatory and policy decisions; and provide technical support and infor-
mation transfer to ensure effective implementation of environmental regulations
and strategies.
This publication has been produced as part of the Laboratory's strategic long-
term research plan. It is published and made available by EPA's Office of Re-
search and Development to assist the user community and to link researchers
with their clients.
E. Timothy Oppelt, Director
National Risk Management Research Laboratory
iii
-------
ABSTRACT
The puipose for this research effort was the development of building standards for radon-
resistant large buildings for the Florida Radon Research Program of the State of Florida.
Fundamental and applied research studies of various building components (floor barriers,
mitigation systems, ventilation systems, fill materials) and performance standards were
conducted. Field evaluation and validation of the draft standards for residential structures has
been carried out in previous studies. The effectiveness of passive barriers, the modification of
the heating, ventilation, and air-conditioning (HVAC) system operations to ameliorate indoor
radon concentration, and the use of active subslab depressurization (ASD) systems have been
investigated in demonstration (new construction) houses and research structures in the state. The
current emphasis was to include the study of large scale buildings as well. The purpose of this
study was to evaluate the feasibility of implementing such radon resistant construction techniques
(especially ASD) in new large buildings in Florida. The techniques developed in this study for
Florida large buildings focused primarily on the demonstration of passive barriers to radon entry
and ASD systems as applied to large buildings. The results of this study will enable existing
subslab pressure field extension (PFE) models to be expanded to include large slabs. The results
of these improved models will be used to design more effective ASD systems for new buildings.
In addition to an ASD system, other radon-resistant construction techniques were designed into
the building, including the installation of adequate subslab membranes, sealing of all slab
openings, and HVAC operation to prevent depressurization of the building interior.
Implementation and installation of these features were monitored as the building was being
constructed. Indoor radon concentrations and radon entry were monitored in the finished
structure with the HVAC system on and the ASD system off, and with the ASD systems
activated in a temporary mode. Results from this study have demonstrated that, with sufficient
attention to building design and construction, significant radon entry into a large building
constructed on a site of high radon potential can be prevented. The effectiveness of the ASD
system as a radon mitigation technique could not be realistically evaluated due to a lack of radon
in the building. However, the PFF, measurements suggest that the design is more than adequate
to meet its purpose of pressure reversal between the building interior and the subslab regions.
iv
-------
ACKNOWLEDGMENT
The authors gratefully acknowledge the contribution of David C. Sanchez, the former
U. S. EPA Project Officer, in the initial planning and design of this research study.
V
-------
TABLE OF CONTENTS
Page
Abstract iv
Acknowledgment v
Figures vi i i
Tables x
Metric Equivalents x i
Glossary x i i
Introduction 1
Background 1
Project objectives 1
Technical approach 2
Materials and Methods 3
Site selection 3
ASD matting plan 4
ASD installation and construction observations 6
Diagnostic measurements 10
Results 12
Site characterizations 12
Pressure field extension measurements 12
Slab crack mapping and measurements 23
Post-construction ventilation and radon entry 24
Conclusions and Recommendations 32
Quality Assurance 32
Data quality objectives and achievements 34
Data quality indicators 34
Data reviews 38
Identification of corrective actions 39
References 39
Appendix 40
vii
-------
LIST OF FIGURES
Number Page
1 Floor plan of the ASD Mulberry Cogeneration Facility, Bartow, Florida 5
2 Layout of the slab and Enka-Vent matting for the Mulberry Cogeneration
Facility showing the location of the ASD riser pipes 7
3 Typical detail for connecting the riser pipe to the Enka-Vent matting at the
ASD site 8
4 Location of the soil radium core samples at the Mulberry Cogeneration site 18
5 Soil radium contents of three cores taken from the Mulberry Cogeneration site 19
6 Soil gas radon concentrations measured under the North end of the Mulberry
Cogeneration Site 20
7 Pressure field extension test results conducted at the Southwest corner of the
Mulberry Cogeneration Facility. The numbers refer to the measurement
locations shown in Figure 8 21
8 Layout of the pressure field extension test points and their relation to the
Enka-Vent matting and vent riser 1 at the ASD Cogeneration Building 22
9 Averaged radon levels measured with the continuous monitors during the
normal building operation and with the ASD system energized at the
Mulberry Cogeneration Facility 27
10 Averaged radon levels of Figure 9 after subtraction of the ambient radon
levels at the Mulberry Cogeneration Facility 28
11 Averaged subslab radon levels before and after energizing the ASD system
at the Mulberry Cogeneration Facility 29
12 Averaged pressure differences between the monitoring locations and the outdoors
at the Mulberry Cogeneration Facility. The values were averaged during
the ASD fan off time and on time 30
viil
-------
LIST OF FIGURES (Concluded)
Number Page
13 Composite plot of multiple tracer gas decay measurements in the Office/
Reception area of the Mulberry Cogeneration Facility. The data set was
used to calculate an average ventilation rate for this area of the building 31
14 Continuous data from the MTG system installed in the Mulberry Cogeneration
Facility showing the tracer gas concentration and the calculated ACH for this
area of the building 33
Al-
AI7 Time dependent Dp values at Mulberry Cogeneration Facility 41-57
A18-
A51 Time dependent radon levels at Mulberry Cogeneration Facility 58-91
A52-
A68 Time dependent temperature and barometric pressure levels at Mulberry
Congeneration Facility 92-108
ix
-------
LIST OF TABLES
Number Page
1 Soil Radium Contents of Three Cores Taken at the Mulberry Cogeneration Site 14
2 Soil Radium and Soil Gas Radon Concentrations Measured at the Mulberry
Cogeneration Site 15
3 Pressure Field Extension Measurement Results Along the East-West Direction
at the Mulberry Cogeneration Facility 16
4 Pressure Field Extension Measurement Results Along the North-South
Direction at the Mulberry Cogeneration Facility 17
5 Slab Crack Analysis at the Mulberry Cogeneration Facility 24
6 HVAC Specifications for the Mulberry Cogeneration Facility 25
7 Average Radon Levels Measured at the Mulberry Cogeneration Facility 26
8 Results From Replicate Placement of CRMs During the Study 35
9 Results of the Bias Determinations for the CRMs 36
10 Calibration Results for the Grab Cells From 1993 and 1994 37
x
-------
METRIC EQUIVALEN TS
Nonmetric units are used in this report for the reader's convenience. Readers more
familiar with the metric system may use the following factors to convert to that system.
Nonmetric Multiplied hv Yields Metric
cfm 0.000472 nr'/s
ft 30.5 cm
ft2 929 cm2
in. 2.54 cm
in. WC 249 Pa
mil 25.4 /j,m
mile 1.6 km
pCi/L 37 Bq/m3
GLOSSARY
ACH
Air Changes per Hour
am
Analog/Digital
AHU
Air Handling Unit
ASD
Active Subslab Depressurization
B&V
Black and Veatch
CF
Calibration Factor
CFC
Chlorofluorocarbon
CRM
Continuous Radon Monitor
CV
Coefficient of Variation
DPU
Data Processing Unit
DQI
Data Quality Indicator
EPA
Environmental Protection Agency
EPERM
High Sensitivity. Standard Chamber
I''AMU
Florida A&M University
FRRP
Florida Radon Research Program
HCFC
Hydrochlorofluorocarbon
xi
-------
GLOSSARY (continued)
HVAC
Heating, Ventilating, and Air Conditioning
MARE
Mean Absolute Relative Error
MOK
Mulberry Cogeneration Facility
MTG
Multigas Tracer
NAREL
National Air and Radiation Environmental Laboratory
NRMRL
National Risk Management Research Laboratory
OA
Outdoor Air
PC
Personal Computer
PFE
Pressure Field Extension
PRD
Passive Radon Detector
QA
Quality Assurance
QAPP
Quality Assurance Project Plan
RAM
Random Access Memory
RE
Relative Error
RPP
Radon Proficiency Program
SD
Standard Deviation
-------
INTRODUCTION
The Florida Radon Research Program (FRRP) was implemented by the State of Florida in
1989 to provide radon research related to the detection, control, and abatement of radon in
Florida buildings. Hie purpose for this research effort was the development of building
standards for radon-resistant buildings. Fundamental and applied research studies of various
building components (floor barriers, mitigation systems, ventilation systems, fill materials) and
performance standards were conducted. Field evaluation and validation of the draft standards for
residential structures followed. The effectiveness of passive barriers, the modification of the
heating, ventilation, and air-conditioning (HVAC) system operations to ameliorate indoor radon
concentration, and the use of active subslab depressurization (ASD) systems have been
investigated in demonstration (new construction) houses and research structures in the state.
Current emphases now include the study of large scale buildings as well. The purpose of this
study was to evaluate the feasibility of implementing such radon resistant construction techniques
(especially ASD) in new large buildings in Florida.
Background
The purpose of this study was to demonstrate radon-resistant construction techniques in
new large buildings. This work complements previous and ongoing diagnostic and mitigation
strategy development work in the FRRP. The techniques developed in this study for Florida
large buildings focused primarily on the demonstration of passive barriers to radon entry and
ASD systems as applied to large buildings. The results of this study will enable existing subslab
pressure field extension (PFE) models to be expanded to include large slabs. The results of these
improved models will be used to design more effective ASD systems for new buildings. In
addition to an ASD system, other radon-resistant construction techniques were designed into the
building, including the installation of adequate subslab membranes, sealing of all slab openings,
and IIVAC operation to prevent depressurization of the building interior. Implementation and
installation of these features were monitored as the building was being constructed. Indoor radon
concentrations and radon entry were monitored in the finished structure with the FIVAC system
on and the ASD system off, and with the ASD systems activated in a temporary mode.
Project Objectives
In order to carry out the objectives of this study, several preparatory steps were necessary,
'fhe first was to identify a number of candidate building projects scheduled to be constructed in
the immediate future in high radon potential areas of Florida. From this list of building projects
it was necessary to identify the owners and builders planning to construct large buildings on these
sites. From this pool, it was imperative that those owners and builders who were cooperative and
willing to participate in a demonstration project be singled out. The target for this project was to
identify eight to ten proposed buildings suitable for inclusion in a demonstration project. Once
this group of buildings was identified, the positive and negative features of each of these
construction projects were compared in order to narrow the list of possibilities down to one or
two building sites that best fit the objectives of the current demonstration. The compatibility of
1
-------
their construction schedules was evaluated to find those that best matched the schedules of the
demonstration project. After selection of the site best suited to the needs of the demonstration,
the demonstration was initiated with several specific objectives. The major objectives were as
follows:
• To work with the designers/architects to design an ASD system for the building
that was also broadly applicable to other similarly sized buildings in Florida
• To test and evaluate passive barrier techniques in large buildings built on soils
similar to those found in Central Florida
• To lest and evaluate the ASD and barrier system effectiveness in a large building
built on a high radon potential site
• To expand existing subslab PFE models to include large slabs.
Technical Approach
The first step was to locate a building site that had high soil gas radon concentrations and
offered a good opportunity to demonstrate the effectiveness of radon-resistant construction
techniques. Because of the time and expense involved in the planning and construction of a large
building, careful attention was given to establishing good communications and a positive
working relationship with the owners, architects, planners, and construction crews in order to
accomplish the desired measurements and results from this study. From the onset it was
anticipated that the investigators would have even less control or influence in scheduling and
altering processes than was the case in projects involving the construction of single-family
houses.
Because of the wide range of issues encountered in the plans, designs, and
implementation of floor, IIV AC. and ASD systems in large buildings, several investigators
covering a comprehensive scope of expertise participated in this project. Florida A & M
University (FAMU), which had the experience of the Hernando County School project, had the
lead in coordinating the development of the ASD system design recommendations. They
conducted most of the documentation of these recommendations and maintained the necessary
communications with the architectural and engineering contractor. In addition to the design of
ASD for the selected building. FAMU also reviewed the building plans to identify probable
radon entry points, and recommended solutions. Based on earlier experience, FAMU also
provided assistance in determining the measurement objectives for the project. Finally, they
provided documentation included in this final report.
The experience that the EPA has gained through years of similar projects sponsored in
schools and other large buildings across the country provided a major resource for this project.
They worked with FAMU to develop the ASD system design and installation recommendations
2
-------
for the building. They also provided consultation to the architectural and engineering firm, the
construction contractors, and the other investigators.
Southern Research Institute assisted with locating building prospects, including building
permit searches and contacting building developers, owners, and designers. Information was
provided to the EPA project officer. They reviewed and provided comments on the design of
ASD for the building. They also provide data collection, including site source determination
similar to that of the New House Evaluation Project protocol, characterization of the as-built
subslab and ASD installation, and PFE measurements. As the on site project lead, Southern
Research coordinated site inspections and visits by other investigators, assisted in maintaining
overall project communications with the building architects and contractors, and performed and
documented the various field measurements. Post-occupancy measurements were planned for a
variety of operating conditions of the building. These operating conditions are described below.
Passive Building —
Measurements of the building parameters were originally to have been made to determine
indoor radon concentrations and radon entry with the building in a "passive" state, that is without
the HVAO or ASD system activated. This set of measurements would have clearly indicated the
radon resistance of the passive barrier alone. However, due to construction delays and changes in
the building use this turned out to be impossible.
Active Building Without ASD System Operating —
Measurements were carried out with the IIVAC on and the ASD system off to evaluate
the mitigative effects of the positive pressure condition imposed by the IIVAC system design.
The amount of outdoor air (OA) drawn into the HVAC system was also varied from minimum to
maximum while monitoring the radon levels and pressure differentials in the building at several
locations.
Active Building With ASD System Operating -
The ASD was then activated with the IIVAC on, and similar measurements were made.
MATERIALS AND METHODS
SiteSelection
In 1992. Southern Research Institute was asked to assist in making some ambient radon
measurements at a construction site in Polk County, Florida. Polk Power Partners, L.P. were
preparing to construct an industrial building on the site located on Highway 555, approximately
10 miles* southwest of Bartow, Florida for Arc Energy and Central Southwest Services, Inc.
The structure was to become the Mulberry Cogeneration Facility's (MCF) Plant Services
(*) Readers more familiar with the metric system may use the conversion factors at the end of the
front matter to convert to this system.
3
-------
Building. The proposed building was to be approximately 21,000 ft? and would consist of a
metal shell on a 6 in. - 8 in. floating slab, l he subslab area was to have approximately five drain
lines running below the slab which were encased in concrete and ran the length of the building
effectively separating the slab into five cells. In addition, all other subslab pipes for power,
water, and other utilities were to be installed incased in concrete.
Six EPERM (High Sensitivity, Standard Chamber) canisters were deployed. They were
placed at the site at heights of 27 ft and 12 ft and at ground level. Oil subsequent visits to the site
gamma measurements were made at ground level and at 12 ft where the EPERMs were deployed.
The results of these gamma measurements resulted in a consistent 40 ^R/hr level at both ground
level and at 12 ft. Permeability measurements were carried out and some radon grab samples
were taken at a depth of 3 ft. Typical of reclaimed land, the results varied from 3.000 to
10.000 pCi/E. On the basis of these preliminary measurements, the Mulberry Cogeneration
Facility was identified as a candidate building for the Large Building ASD Study. The floor plan
of the MCF building is shown in Figure 1. Note that the slabs for the Control Room and the
DPU Rooms were poured at a recessed depth of 18 inches relative to the remainder of the slabs.
A planning meeting to discuss the site was held at EPA-XRMRL. RTP, XC on January
20, 1993 with David Sanchez and A. B. Craig of EPA, Susan McDonough of Southern Research
Institute and Tom Pugh of FAML'. A project conference was held at Black & Veatch offices in
Kansas City, Missouri on the following day. As a result of this meeting the owner decided to
incorporate both passive sealing modifications and an AS1) system into the structure.
ASP Matting Plan
The proposed facility and plant services building drawings were obtained from the
contractors. The plans were reviewed and probable radon entry points were identified. A
proposed design of an ASD system was developed at the initial planning meeting attended by
EPA. FAMIJ and Southern Research Institute researchers. Several areas of concern were
identified with respect to various subslab and building design features. Subsequent to the
planning meeting, a conference with Black and Veatch (B&V) was attended by EPA, FAMU,
and Southern Research. The specific project goals and objectives, and the overall intent/theory
of radon resistant construction were conveyed to members of the B&V design team. Drawings of
the proposed ASD system, developed by the research team, and existing passive radon controls,
developed by the B&V team, were discussed. The B&V team was then left to design, price out.
identify schedule conflicts and obtain owner approval to incorporate the ASD system in the final
building design. FAMU contacted UF to obtain their input in regards to the adequacy of the
system proposed by the research team. Several iterations of the residential PFE model were run
to ensure the system was capable of providing the required air flows throughout the system. The
B&V design team submitted preliminary design drawings to the research team for comment on
the system design. The comments were relayed to the B&V team and were ultimately included
in final system design.
4
-------
— 210'-0"
0
1
b
(S
Water
Treatment
Lab
Slab Recessed 18'
Kit-
hen
^onf
Rocpt.
Area
Off.
Off.
Off,
Electrical Equipt. Rnn
Men's
Locker
Women's
Locker
HVAC
Maintenance
Figure 1. Floor plan of the ASD Mulberry Cogeneration Facility, Bartow, Florida.
-------
The building has unique features, most notably the encasement of all underslab plumbing
and conduit in reinforced concrete. In virtually every case, the plumbing trenches were
backfilled with concrete to the elevation of the bottom of the slab. The trenches were usually
more than 3 ft deep. They were slightly overexcavated, and 2-4 inches of concrete was cast
over the exposed bottom of the trench to create a work surface. Piping and reinforcing was
installed, and forms were set to limit the width of the concrete to approximately 20 inches. After
the concrete was cast and the forms stripped, the remainder of the trench was backfilled with
compacted earth. This had the effect of compartmentalizing the slab into many discrete zones.
As a result, the ASD mailing design mighl appear overly conservative, unless consideration is
given to the need for intersecting each of these areas with some portion of a ventilation mat.
Despite these constraints, a reasonably simple and efficient use of ventilation mat was achieved.
The current draft Florida radon standard would allow for the ASD system to consist of
ventilation matting such as Enka-Vcnt spaced on 20 ft centers. The recommended system layout
for this building ulilizcs ventilation strips on 15 ft centers. This is a result of several factors:
• The building utilizes a 30 ft bay spacing which lends itself to the 15 ft module
• The performance of the mat in this configuration had nol been extensively
modeled, so a slightly conservative approach was considered prudent
• The air-permeability characteristics of the soil immediately beneath the slab were
not well established.
The locations of the matting strips are shown in Figure 2. Also shown are the locations of five of
the seven risers connected to the Bnka-Vent material. The method used to connect the risers to
the mat is illustrated in Figure 3. Riser numbers 5 and 7 were omitted during construction and
the pipe connections to the matting were closed and sealed. These changes were necessitated by
construction changes in the building after the slabs were poured.
ASD Installation and Construction Observations
Personnel from Southern Research and FAMU made several visits to the job site
throughout the construction period. The purpose of these visits was to monitor, but nol affect,
the construction process. However, the construction crews and their supervisors frequently asked
advice about specific ASD installation issues, which was then freely given. Before inclusion of
Southern Research or FAMII personnel into the project, and based on advice taken from publicly
available literature, the contractor had agreed to install 6-mil polyethylene beneath the entire
subslab area, including below and along the inside surface of the perimeter grade beams.
Although this step exceeded current recommendations, it is not believed to have had a significant
effect on the effectiveness of the barrier, since the condition of the polyethylene rapidly worsened
as the beams were cast, stripped, backfilled, etc. During the installation of the ventilation mat, it
became apparent that large amounts of sand would be tracked onto the mat surface by workmen,
and steps were taken to have them step over, rather than walk on, the mat. Some consideration
6
-------
— 210'-0"
R3 R5
R2
R1
—ft 1 i—
R6 R4
Figure 2. Layout of the slab and Enka-Vent matting for the Mulberry Cogeneration Facility
showing the location of the ASD riser pipes.
-------
Riser pipe
Concrete Slab
Tape polyethylene
to riser
mil polyethylene
Fill
oo
tKiUfiUuL'uUUtiUiitilHl tia
Enka-Vent Continuous Strip
24" Long Enka-Vent strip centered under riser
Figure 3. Typical detail for connecting the riser pipe to the Enka-Vent matting at the ASD site.
-------
should probably be given to requiring clear polyethylene whenever an ASD system is roughed-in,
so that an inspector can look for sand contamination and blockage of the mat. This is true for all
sizes of structures, but is especially important on large slabs where considerable time is required
to install the mat and cover it with polyethylene.
Another problem which presented itself during the slab-preparation process was the
cutting of the vapor barrier when reinforcing steel was dropped or dragged across it, especially if
the point of contact was at the ventilation mat. This problem may be specific lo this structure,
but will probably occur to some degree in all buildings. Careful repair and inspection will be
necessary to limit this.
The slab was cast in four sections, beginning with the lowest level (the Control Room and
the DPI * Room). This resulted in some sections of ventilation mat being exposed to wear and
tear, sand, and waste concrete that was dragged over the forms or otherwise spilled. We advised
the contractor to "sleeve" the mat for a distance of approximately 6 - 7 ft at these points. This
was easily accomplished by cutting a section of polyethylene approximately 6 ft x 6 ft and
placing it at the edge of the pour immediately before installation of the mat. The polyethylene
was then folded over the top of the mat. and secured with tape. While this prevents the mat from
communicating directly with the soil in this small section, this effect on the performance of the
system is negligible. The possibility of completely blocking flow along the mat at this point,
though, seems to be effectively prevented by this practice. It is reasonable to assume that a fully
blocked mat might still exhibit some very slight flow, since the pressure field will propagate to
some extent through the surrounding soil. This may be a point worth investigating in detail in
later research.
The slab had one final feature unique to the experiences of this program — several
hundred twisted copper strand grounding cables were installed which penetrated the slab. Since
there is considerable open space between each intersecting stand of wire (approximately 26% of
the area of the cable itself which was generally 1.5 inches in diameter), these were potential entry
points that were not anticipated during our earlier consultations. However, it is not difficult to
imagine a variety of potential solutions to this rather unusual situation .
Despite having been heavily reinforced and cured in compliance with the current
recommendations, there was some cracking visible in the slab. The effects of these cracks on
radon entry are discussed elsewhere in this report.
In conclusion, it was not particularly difficult for the workmen to properly install the
ASD system or to achieve a high degree of effectiveness with the slab sealing practices provided
they had been through a short training program. There was some learning required on their part,
and this advanced most quickly through on-site demonstration rather than discussion or reference
to sketches.
9
-------
Diagnostic Measurements
Pressure Field Extension —
Pressure field extension measurements were carried out by attaching an inline radon
mitigation fan to one of the ASD risers to produce a pressure field in the Enka-Vent mat system
with the other risers capped and sealed. Subslab pressures were measured using a
micromanometcr attached to test holes drilled through the slab.
Slab Crack Characterization ~
Analysis of the flow through the slab cracks and the radon concentration infiltrating
through these cracks was carried out using techniques developed for the FRRP1.
Post-Construction Ventilation and Radon Entry Characteristics —
Ventilation and radon entry into the building was monitored using two systems. In the
case of the building ventilation, a tracer gas technique was used. For radon measurements a
Campbell Scientific, Inc. 21 XL Micrologger with 40K RAM storage system was used.
The 21 XL devices each have 16 single-ended analog input channels (8 different channel
inputs) that can digitize analog signals from ± 5 millivolts to ± 5,000 millivolts with an accuracy
of 0.1% of full scale reading. These analog/digital (A/D) inputs can be used to measure signals
from analog devices such as pressure transducers, wind vanes, temperature probes (both
thermistor and thermocouple), and shaft positions such as dampers and control valves. The
21 XL also has four pulse counters that can be used to count and store the pulses generated by
such devices as the Pylon AB5 and the Femto-Tech radon monitors, rain gages, wind speed
monitors, door closure switches, and HVAC sail switches. The units have enough internal RAM
to store 19,296 data values. The devices can also be accessed remotely via a personal computer
(PC) and telephone modem to download accumulated data and to modify the data taking
program in the device. Incorporated into this system was a Campbell Scientific, Inc. SDM-INT8
Eight Channel Interval Timer. In the simplest use of this module, one unit connected to a 21 XL
expands the pulse input capability of the 21XL from 4 pulse channels to 12 channels (4 channels
on the 21 XL and 8 channels on the SDM-INT8). Thus with one 21 XL and one SDM-1NT8 the
counts per execution interval from 12 Pylon AB5 or Femto-Tech radon monitors can be
accessed and stored in the datalogger. In the 21 XL system installed in the Cogeneration building,
the following parameters were measured (for locations refer to Figure 1):
1. Ap, between the Electrical Equipment Room and the DPU Room.
2. Ap_, between the DPU Room and outside the building.
3. Ap3 between the HVAC Mechanical Room and the DPU Room.
4. Ap4 between the Reception Area and the DPU Room.
5. Ap5 between the subslab area and the DPU Room.
6. Temperature on the 21XL Panel located in the DPU Room.
7. Barometric pressure outside the building.
8. Radon levels under the slab using a Pylon AB5 monitor operating in the pumped
mode.
10
-------
9. Radon levels in the DPU Room using a Pylon AB5 with a passive radon detector
(PRD) cell.
10. Radon levels outside the building using a Pylon AB5 monitor operating in the
pumped mode.
11. Radon levels in the Electrical Equipment Room using a Femto-Tech ionization
monitor.
12. Radon levels in the Control Room using a Femto-Tech ionization monitor.
13. Radon levels in the Water Treatment Area using a Femto-Tech ionization
monitor.
14. Radon levels in the Reception Area using a Femto-Tech ionization monitor.
Data from each of these parameters were averaged (or totalized for the radon monitors) and
stored every 30 minutes. This datalogging system was installed in the building on August 8,
1994 and was made fully operational shortly thereafter.
For measurements of building ventilation a number of techniques, both passive and
active, are available for characterizing airflow and transport in a building by use of tracer gas.
The most widely used and simplest technique is the tracer gas decay method. In this method a
tracer gas is injected into a well-mixed zone of the building. Once the concentration becomes
uniform the injection is stopped and the concentration of gas is periodically sampled over a
period of several hours. From the decaying concentration information the zone (or building)
ventilation rate can be calculated. This technique is simple to perform and requires little
expensive equipment. However, the measurements are not continuous and the assumption of a
well mixed zone (or building) is often not realized.
Active multi-gas analyzers can give infiltration data on multiple building zones on a real
time basis. A system built at Southern Research Institute and used in FRRP large building
projects2 has the capability of reporting information continuously with up to 4 gases in up to 8
zones. The constant injection technique used by this device is a very powerful but complex
method. In this method, several different tracer gases arc constantly injected into the building
with each gas going into a different zone. Simultaneously, the concentrations of all the gases are
measured in all of the zones on a continuous basis. For the case where the building can be
considered a single zone, the air infiltration rate is simply a function of the rate of change of the
concentration and the tracer injection rate. When more than one zone is called for. the equations
governing the level of tracer gases are a series of coupled first order differential equations. The
advantage of the constant injection method is the ability to continuously measure the air
flowrates (interzonal and infiltration) in a multizone building. The active multigas tracer (MTG)
system described above was installed in this building. The system is based upon a Bruel & Kjaer
Type 1302 photoacoustic Multi-gas Monitor. The MTG system incorporates separate tracer gas
dosers and sampling systems (based upon a design developed by David Bohac). The system
allows the injection of up to 5 different tracer gases in a multizone environment and the sampling
of these gases in 5 separate zones of a large building. The instrument provides measurements of
the air movements inside and through the shell of large buildings. In addition, the B & K
analyzer has the capability of monitoring other pollutants with characteristic infrared absorption
11
-------
bands within the available atmospheric "windows" defined by the water and carbon dioxide
absorption spectra.
For the present study the MTG system was configured to inject three separate gases and
sample at five locations in the MCF building. The injection locations and the gases injected at
these locations are as follows:
Gas 1. Sulfur Hexafluoride (SF0) injected into the Control/DPU rooms
Gas 2. Dichlorodifluoromethane (CFC-12) injected into the Office/Reception areas
Gas 3. Chlorodifluoromethane (IICFC-22) injected into the Electrical Equipment room.
The sampling locations were:
1. Control/DPU room
2. Electrical Equipment room
3. The Storage area in which the M TG equipment was located (for QA checks)
4. Water Treatment area
5. Office/Reception area.
6. Plenum above the Office drop ceiling.
Attempts were made to use the MTG system to measure and calculate the ventilation
rates of the three major zones of the building.
RESULTS
Site Characterizations
Core samples were taken at three locations prior to pouring the slab. These locations are
shown in Figure 4. Permeability and soil gas radon measurements were also carried out prior to
slab pouring. However, due to problems with the permeameter the only reliable data were
obtained in the North end of the building. The results of the core samples are tabulated in Table
1 and illustrated in Figure 5. In each core, soil samples were recorded down to a depth of about
60 inches with separate samples every 4-6 inches. The average soil radium content for cores
1,2, and 3 were 5.9, 3.9, and 6.5 pC'i/g respectively with an average for all three cores of
5.44 pCi/g. It is seen in Figure 5 that the radium content has a tendency to drop with depth with
the higher levels within 10-20 inches. The results of the soil gas samples are tabulated in Table
2 and illustrated in Figure 6. The average soil gas radon concentration was approximately
9,905 pCi/L with no diseernable pattern under the north end of the slab.
Pressure Field Extension Measurements
After the slab was poured, PFE measurements were carried out in the Southwest corner
of the slab. These measurements were undertaken not only to obtain a measure of the PFE under
the slab, but also to determine the effects that deleting riser R-4 would have on the effective
12
-------
coverage of the ASD system. The results of these tests are tabulated in Table 3 and Table 4 and
illustrated in Figure 7. The physical locations of the test points are shown in Figure 8. The tests
were carried out with an inline fan installed on riser R-l and with
13
-------
TABLE 1. SOIL RADIUM CONTENTS OF THREE CORES
TAKEN AT THE MULBERRY COGENERATION SITE
Depth (inches) Radium Content fpCi/g)
Core 1 Core 2 Core 3
0-6 6
0-12 7.6 7.7
6-12 6.4
12-16 8.3
12-22 6.4 6.1
16-22 10.5
22-26 3.75
22-27 6.45 6.35
27-33 7.6 2.8
27-36 7.5
33-36 2
34-38 3.3
36-42 10.2 7.9
38-43 1.2
42-48 2
43-48 2
42-54 3.1
48-53 1.9
54-60 3.5
14
-------
TABLE 2. SOIL RADIUM AND SOIL GAS RADON CONCENTRATIONS
MEASURED AT THE MULBERRY COGENERATION SITE (at 48 inches)
Sample Soil Gas
Number Radon
(pCi/L)
PI
9683
P2
9712
P3
6390
P4
10784
P5
5548
P6
1592
P7
8189
P8
4778
P9
35534
P10
6840
Mean
9905
Coefficient of Variation 95%
15
-------
TABLE 3. PRESSURE FIELD EXTENSION MEASUREMENT RESULTS
ALONG THE EAST-WEST DIRECTION AT THE MULBERRY
COGENERA.TION FACILITY (SEE FIGURE 8.)
Riser R1
Riser R1
Test
Test Hole
Test Hole
Test Hole
Dp
Flowrate
Hole
X
Y
Dp
(Pa)
(cfm)
ID U
Coord.
Coord.
(Pa)
113
122
EW1
2
19
-47
113
122
EW2
4
19
-97
113
122
EW3
6
19
-99
113
122
EW4
9
19
-101
113
122
EW-W
11
19
-95
113
122
EW5
12
19
11
113
122
EW5-F
13
19
-97
113
122
EW6
15
19
-97
113
122
EW7
18
19
-104
113
122
EW8
21
19
-105
113
122
FAV9
24
19
-107
113
122
EW10
27
19
-108
140
138
EW11
30
19
-103
154
145
EW12
19
-124
154
145
EW13
36
19
-119
154
145
EW14
39
19
-108
154
145
EW15
42
19
-238
154
145
EW16
45
19
-143
16
-------
TABLE 4. PRESSURE FIELD EXTENSION MEASUREMENT RESULTS
ALONG THE NORTH-SOUTH DIRECTION AT THE MULBERRY
COGFNFRA'I FOX FACILITY (SEE FIGURE 8.)
Riser III
Dp
(Pa)
Riser R1
Flowrate
(cfm)
Test
Hole
ID#
Test Hole
X Coord.
Test Hole
Y Coord.
Test Hole
(Pa)
111
120
NS1
24
2
-10
111
120
NS2
24
4
-34
111
120
NS3
24
6
-65
11 1
120
NS4
24
8
-87
111
120
NS5
24
10
-112
111
120
NS6
24
12
-125
111
120
NS7
24
15
-129
111
120
NS8
24
18
-151
110
120
NS9
24
19
-111
110
120
NS10
24
21
-124
110
120
NS11
24
24
-134
109
120
NS12
24
27
-131
109
120
NS13
24
30
-130
109
119
NS14
24
33
-107
17
-------
— 210'-0"
Core 3
J
Core 1
Core 2
Figure 4. Location of the soil radium core samples at the Mulberry Cogeneration site.
-------
1 pCi/g
-10 -
-20-
c
sz
+-•
Cl
0)
D
-30 -
-40-
50 -
-60
8
0
4
12
2 6 10
Radium Content (pCi/g)
-I- 1st core • 2nd core 3rd core
Figure 5 . Soil radium contents of three cores taken from the Mulberry Cogeneration site.
19
-------
40 •
35-
30'
25'
«
•o
c
o
•> 20-
D
15-
10'
35534
/—?!
Data sampled at 4 ft depths
9683
9712
10784
6390
up
*P
8189
5548
up
1592
p
4778
up
*Up
6840
x yi
T
PI P3 P5 P7 P9
P2 P4 P6 P0 P10
Location Number
Figure 6. Soil gas radon concentrations measured under the North end of the Mulberry
Cogeneration site.
20
-------
50-
D1
D2
..i.jn..
~3
~4
¦2L*~3» 4JW3e.«.J.« 1 - Yrm
~5 7m 6m 9B910- T1
¦RM
~6
13'
07
i O10 12L
{ ,u D11 o 12 D13
-3 0 5
Distance (ft)
East-West O North-South
Figure 7. Pressure field extension test results conducted at the Southwest corner of
the Mulberry Cogeneration Facility. The numbers refer to the measurement
locations shown in Figure 8.
21
-------
13 14
Enka~Vent
Mat
Fan
Figure 8. Layout of the pressure field extension test points and
their relation to the Enka-Vent matting and vent riser 1
at the ASD Cogeneration Building.
22
-------
risers R-2, R-4, R-5, and R-6 capped. Risers R-3 and R-7 were removed after the slab was
poured due to changes in the building usage. The openings to the matting were closed and
sealed.
In Figure 7 the distance plotted along the horizontal axis is the distance away from the
point at which the North-South (NS) and East-West (EW) traverses cross (as shown in Figure 8).
Notice in Tables 3 and 4 that the suction pressure and flowrate at the fan (R-1) varied during the
later portion of the test. This as due to a rapid change in atmospheric conditions and other
problems at the site during that portion of the testing. Due to a storm front coming through the
area, the outdoor wind speed increased to between 15 and 20 mph which probably increased the
flow through the riser pipe. The variations in the fan operation are not believed to be serious
enough to question the results. The subslab pressures averaged about -100 pascals (-0.4 in. WC)
relative to atmospheric and as might be expected were generally higher (more negative) in the
vicinity of the Enka-Vent matting. This subslab pressure level should be more than adequate for
effective operation of the ASD system.
Slab Crack Mapping and Measurements
Crack analysis was carried out on three prominent slab cracks on October 22, 1993. The
results of this analysis are as follows.
• Crack I was a shrinkage or settling crack about 1/32 in. wide and was about 20 -
25 feet in length. Crack 1 was only one of numerous shrinkage cracks with a total
length of perhaps 700 feet. It is doubtful if any of these cracks completely
penetrated the slab which accounts for the low radon concentrations measured
from this crack.
• Crack 2 was located in construction joint 106 and appeared to have a path for soil
gas to go through or around the vapor barrier. Crack 2 was also about 1/32 in.
wide and including all three construction joints totaled approximately 300 linear
feet. Radon levels measured were higher than that in Crack 1 but not excessively
high.
• Crack 3 was a portion of the floating edge crack where the sealant had pulled
away. Crack 3 ran around the entire perimeter of the building slab a distance of
620 feet and was on the average about 1/4 in. wide. There is no vapor barrier
under this floating edge joint and communication with the soil is high, which
accounts of the high radon concentrations measured here.
Based upon these visible cracks, a conservative estimate of the total crack area is
approximately 14 ft2 (1.3 m2) out of a total slab area of 21,000 ft2, a figure of less than 0.1% of
the total area. Analysis was carried out using the standard FRRP methodology'. The results are
shown in Table 5. In each case the flow of soil gas through the cracks (as well as the
23
-------
concentration of radon in the gas) was sufficiently low that it should not significantly contribute
to the indoor radon levels at realistic pressure differences.
TABLE 5. SLAB CRACK ANALYSIS AT THE MULBERRY
COGENERATION FACILITY
Crack Number
and
Type
Effective
Leakage Area
per Unit Length
(lV'/ft)
Radon
Concentration
(pCi/L)
1-Settling
3.35xl0'08
9
2-Construction Joint
3.72x10-'°
14
3- Floating Edge
2.41x10"r'8
225
Post-Construction Ventilation and Radon Entry
Radon Entry—
The data from the continuous monitoring system are plotted on a day-by-day basis in
Figure A1 through Figure A68 of the Appendix. These data plots cover the period 8/17/94
through 1/06/95. Operation of the building can be divided into three periods:
Period 1. From 9/08/94, when the building IIVAC data logger was first installed,
until 10/22/94 when the ASD system was temporarily energized.
Period 2. From 10/22/94, when the ASD mitigation fan was installed and energized,
until 10/28/94.
Period 3. From the time the ASD fan was turned off until 11/01/94 during which
time several building operation upsets were encountered.
During Period 1 several conflicting factors were in operation in the building. During the
first part of that period the HVAC test and balance company was changing the operation of the
HVAC system, on 8/8-9/94 and again on 8/23/94. Specifications for the building IIVAC systems
are summarized in Table 6. AIIU-1 serves the offices and reception areas and AIIU-2 supplies
conditioned air to the Control Room and to the DPU Room. AIIlJ-l has about 19% OA, AIIU-2
has about 7% OA, and AHU-3 has 100% OA.
24
-------
TABLE 6. l-lVAC SPECIFICATIONS FOR THE MULBERRY
COGENERATION FACILITY
AIIU #
Total Flow
(elm)
Outdoor Air Flow
(elm)
Area Served
1
7206
1349
Offices
0
JL.
4960
341
DPU & Control
3
44,977
44,977
Elect. Equip. Rm
The radon levels for Period 1, while fluctuating somewhat, were very low overall and
were indeed were barely above ambient concentrations. These are shown in Table 7 where, with
the exception of the subslab, the radon levels during Period 1 averaged less that 1 pCi/L. These
values are shown graphically in Figure 9.
During Period 2 an inline radon fan was connected to Riser 5 to temporarily activate the
ASD system. These results are also shown in Table 7 and in Figure 9. No significant reduction
in the low radon concentrations was observed; in fact, at first inspection it would appear that the
ASD operation raised the radon levels in the occupied areas of the building. However, upon
closer inspection of the data it is seen that the ambient radon levels increased as well over this
time period from 0.25 pCi/L in Period 1 to 0.64 pCi/I. in Period 2. The increases inside the
building followed the ambient levels during this same time period. In order to better understand
the results of the ASD operation, the values in Table 7 were adjusted by the changes in the
ambient radon levels. The results are shown in Figure 10 where it is seen that the changes in
average indoor radon are less than 0.5 pCi/L and probably not experimentally significant. In
short, the base levels of radon in the building appear to be so low that no appreciable change
results from activating the ASD system. In contrast, the subslab radon levels, which during
Period 1 averaged about 13,000 pCi/L as shown in Table 7, were noticably decreased during and
shortly after ASD activation. It is seen in Table 7 and Figure 11 that activation of the ASD
system dropped the subslab radon levels by approximately 25%.
With the exception of the reception area, the occupied zones were pressurized relative to
the outdoors. This is shown in the Figure 12 where the average pressure differences relative to
ambient are plotted for each of the five zones monitored. The time traces of the pressure
measurements are shown in more detail in Figures Al- A17 in the Appendix. These plots show a
25
-------
TABLE 7. AVERAGE RADON LEVELS MEASURED AT THE MULBERRY
COGENERATION FACILITY
Condition
of the
ASD
System
Subslab
(pCi/L)
DPU
Room
(pCi/L)
Ambient
Pumped
(pCi/L)
Elect.
Equpt.
Room
(pCi/L)
Control
Room
(pCi/L)
Water
Treat.
Room
(pCi/L)
Office/
Recpt.
(pCi/L)
ASD Off
9/08 to
10/22/94
13043
(13043)
0.73
(0.21)
0.52
0.70
(0.18)
1.09
(0.57)
0.80
(0.28)
0.72
(0.20)
ASD On
10/22 to
10/28/94
9772
1.14
(0.34)
0.80
1.50
(0.70)
1.60
(0.81)
1.20
(0.40)
0.96
(0.17)
ASD Off
10/28 to
11/01/94
9486
0.71
(**)
1.09
0.74
1.12
(0.04)
1.01
(**)
0.70
Notes: Numbers inside () are after subtracting the ambient radon background levels. (**)
indicates that the radon levels were below the lower limit of the radon monitor.
consistant pressurization of most zones with significant fluctuations which appear to he due to
changes in status of some building system which was not specifically monitored, such as
ventilation fans in the bay areas. It was observed that the door connecting the Mechanical Room
to the outdoors was frequently left ajar, resulting in large swings in several pressures at
unpredictable times. The Office/Reception areas fluctuated in pressure relative to the outdoors,
although on the average these areas were depressurized. Figure 12 also shows the effects of the
ASD fan upon the subslab pressures. It is also seen that the pressure under the slab without the
ASD system running is quite positive. This is most likely due to air from the building interior
being forced down under the slab through the construction joints and floating edge cracks.
Ventilation-
Measurements of the ventilation of the five zones of the building were carried out using
both the constant injection method and the decay method. In this method, Gas-3 was injected for
a finite time and then the injection was stopped for two hours and the gas concentrations allowed
to decay. In Figure 13 a composite of the decay method results for several days of measurements
is shown. As seen in these data, tracer gas is injected and the concentrations allowed to
equilibrate until 10:00 am. At 10:00 am the injection is stopped and the concentrations followed
as ventilation occurs, illustrated by the exponential decrease. When the concentrations arc back
to the background levels the injection of tracer gas is started again (about noon). From this
composite data set an exponential decay function X was fitted to calculate an air change rate for
the Office/Reception areas according to the equation C = C. • e"" where C is
26
-------
/ Control Rm.
Elec.Eqpt.Rm,
DPU Rm
/ Water Trmt.Rm.
Off./Recpt.
Amb. Pmp
ASD Off ASD On
ASD Operation Condition
Figure 9. Averaged radon levels measured with the continuous monitors
during the normal building operation and with the ASD system
energized at the Mulberry Cogeneration Facility,
27
-------
Is Jr / Control Rm
lir—7
w / Elec.Eqpt.Rm.
/DPU Rm
/ Water Trmt.Rm.
Off./Recpt.
ASD Off ASD On
ASD Operation Condition
Figure 10. Averaged radon levels of Figure 9 after subtraction of the
ambient radon levels at the Mulberry Cogeneration Facility.
28
-------
ASD Off ASD On
ASD Operation Condition
Figure 11. Averaged subslab radon levels before and after energizing the ASD
system at the Mulberry Cogeneration Facility.
29
-------
_/ HVAC Rm/Out
/ EE/Out
DPU/Out
_/ SS/Out
/ Off./Out
ASD Off ASD On
ASD Operation Condition
Ficure 12 Averaged pressure differences between '.lie monitoring locations and the oudoors
at the Mulbcrrv Conueneration Facility. The values were averaged during the
ASD fan offline and on tune.
30
-------
¦' %ALtxpnx,/J H'4 ¦'/<'
* •&;};\kTiW"P' 'h'-'J M;
|# mA' u'W/ f« / 1 i; 'V V
t?iiA':rv:- .<• •••¦. Ai > ... ',' v
12:03
noon
04:00
Time of Day
TG Cone. 3.0 ACH Fit
Figure 13. Composite plot of multiple tracer gas decay measurements in the Office/
Reception area of the Mulberry Cogeneration Facility. The data set was
used to calculate an average ventilation rate for this area of the building.
31
-------
the tracer gas concentration at time t, C, is the equilibrated concentration before the injection is
stopped, and X is a decay function proportional to the room volume and ventilation. As seen in
Figure 13 the best fit corresponded to a ventilation rate of 3.0 air changes per hour (ACH).
The ACH values lor the Conirol/DPU areas were calculated on a continuous basis and are
plotted in Figure 14. Here the concentrations of Gas-1 (SF6) are plotted along with the calculated
ACH for these areas of the building. The average value was calculated to be approximately
1.7 ACH.
Attempts to measure and calculate the ventilation rates for the South end of the building
were not successful. In the South end, the area is served by AHU-3 and is operated at 100% OA.
Consequently, very little tracer gas injected into the area could be measured, and only a lower
limit can be estimated for the ventilation rate.
CONCLUSIONS AND RECOMMENDATIONS
In view of the low radon levels inside the building and the fact that the site has a high
radon potential, it appears that either the radon barrier system installed under the slab, or the
overall pressurization of the IIVAC systems, or some combination of the two, is very effective in
preventing radon entry into the building. In either case, results from this study have
demonstrated that with sufficient attention to building design and construction, significant radon
entry into a large building constructed on a site of high radon potential can be prevented.
Due to the continuous occupancy of the building starting before completion of
construction, the planned passive (IIVAC off) experiments were not possible. These
experiments would have belter defined the relative effects of both the barriers and the HVAC
operation. However, since at least part of the structure is apparently depressurized with respect
to outdoors, we assume that the primary mitigation structural element was the slab/barrier
integrity rather than the IIVAC system. Further measurements during an unoccupied period
without HVAC operation would have been highly desirable.
The effectiveness of the ASD system as a radon mitigation technique could not be
realistically evaluated due to a lack of radon in the building. However, the pressure field
extension measurements suggest that the design is more than adequate to meet its purpose of
pressure reversal between the building interior and the subslab regions.
QUALITY ASSURANCE
In 1993, the EPA approved a Quality Assurance (QA) Project Plan (QAPP) (#93012) for
the "Study of Radon Entry and Control in Large Foot-Print Structures" to develop suitable
diagnostic and mitigation techniques for existing large buildings in Florida. When the
opportunity presented itself for this investigation to evaluate the feasibility of implementing
radon resistant construction techniques in a new building, this approved QA plan was used to
32
-------
0-| . | j . , | pO
09/28 10/08 10/18 1C/28
10/03 10/13 10/23 11/02
Date
TG Cone. ACH
Figure 14. Continuous data from the MTG system installed in the Mulberry Cogeneration
Facility showing the tracer gas concentration and the calculated ACH for
this area of the building.
-------
guide the radon screening measurements made of the site that year. In early 1994, the EPA
approved a similar QAPP (#94036) for this and other Large Building 1994 Demonstrations to
guide the collection and analysis of subsequent measurements. The radon measurements were
made in accordance with procedures found in the. EPA's "indoor Radon and Radon Decay
Product Measurement Device Protocols" manual3. The differential pressure measurements were
made using MODUS Instruments. Inc. pressure transmitters according to their operating
instructions.
Data Quality Objectives and Achievements
The major objectives of this project were to design an ASD system for the building that
would be applicable to other similarly sized buildings in Florida, to evaluate passive barrier
techniques in large buildings built on high radon potential reclaimed phosphate mining soils
similar to others found in Central Florida, to evaluate the ASD and barrier system effectiveness
in this building, and to expand existing sub-slab PFE models to include large slabs. The ASD
system was designed and installed in the building with redundancy because there was such a high
source potential at the site and the building's owners originally wanted to minimize the indoor
radon concentrations found in the structure. The PFE measurements indicated that the system
worked quite well even with some of the redundancy eliminated. The passive barrier techniques
installed in this building proved to be extremely effective at preventing radon entry to the
structure based on the near ambient radon concentrations measured with the building operating in
its normal mode. Because of the barrier's effectiveness, insufficient indoor radon concentrations
were measured in the baseline mode to be able to evaluate the ASD system effectiveness. The
PFE measurements were transmitted to other FRRP researchers to use to expand their existing
sub-slab PFE models to include large slabs. Their findings are not included in this report.
Data Quality Indicators
The data quality indicator (DQI) goals for precision, accuracy, and completeness arc
described in the QAPP (#94036) of March 1994. The precision goals for radon concentrations of
4 pCi/L or greater are given in terms of a coefficient of variation (CV) or relative standard
deviation and are the 10% levels listed as achievable in the EPA's protocols3. The precision goal
for differential pressure of 25% CV was set higher because many of the measurements are
expected to be in the range of ±1 Pa, and this level of precision will be quite adequate in this
range of measurements. The accuracy goal for radon concentrations was the criterion for a pass
in the EPA's Radon Proficiency Program (RPP)4, ±25% bias for concentrations above 4 pCi/L.
This bias was also considered adequate for the differential pressure measurements. The target
completeness goal was 90% for each measurement parameter. Because the soil radium and
emanation analyses were performed by another laboratory, it is not known what their QA goals
were or how well they were achieved.
Continuous Radon Monitors-
Precision—Before any continuous radon measurements were started in this building in
March 1994, three of the CRMs were placed in the same location and measured the radon
34
-------
concentration there simultaneously for about two days. [The other three monitors (belonging to
the EPA) were treated similarly, with equally successful results, but the actual data were not
provided.] After the end of the measurements, this procedure was repeated. In between, there
were two occasions in which two of the monitors were exposed over the same time in the same
location. The resulting measurements from each of these replications are given in Table 8. The
DQI for the precision of the CRMs was a CV of 10% for radon concentrations greater than
4 pCi/L, Because the indoor radon concentrations in the building averaged considerably less than
2 pCi/L, an acceptable measure of precision in this range was considered to be a standard
deviation (SD) of less than 0.4 pCi/L. All of these measures of precision are within one of these
goals. Therefore, the precision of the CRMs was considered to be quite acceptable.
TABLE 8. RESULTS FROM REPLICATE PLACEMEN T OF CRMs DURING THE STUDY
CRM
Time Period
3
4
172
538
CV
03/02-03/04/94
16.5
19.1
16.2
9%
08/29-09/12/94
0.7
1.2
0.3*
09/12-10/06/94
0.56
0.62
7%
06/14-06/16/95
10.0
9.8
1%
* standard deviation
Accuracy—The three EPA CRMs were exposed to 18.4 pCi/L in the EPA radon chambers
at National Air and Radiation Environmental Laboratory (NAREL) in Montgomery, Alabama,
from 28 February until 02 March 1994. Based on this exposure, a calibration factor (CF) was
calculated lor each monitor. The three CRMs belonging to Southern were exposed to 18.3 pCi/L
in the EPA radon chambers at NAREL later in March 1994 before they were used in the field for
this project and again in June 1995 after the completion of the project. These exposures in the
chambers were at near constant concentrations for two to three day intervals. The measurements
were calculated for each monitor as would have been done in the field. After the exposures,
NAREL sent the actual chamber concentrations (8.9 pCi/L for monitors 3 and 4 and 9.1 pCi/L for
monitor 172 in 1995).
The difference between the measured value and the actual concentration divided by the
actual concentration is expressed as the bias or relative error (RE), given as a percentage. The
DQI goal for accuracy was ±25% relative error for concentrations greater than 4 pCi/L. Table 9
lists the results of the bias determinations made for the CRMs based on these two sets of
calibration runs. The mean and the mean absolute relative error (MARE) (the mean of the
absolute values of each of the individual REs) of each set of calibration measurements are also
given in the table. Each of the individual REs and both of the MAREs were well within the
target bias of -25%; therefore, the accuracies of the CRMs were considered to be quite adequate.
After these results were received, the CF for each of the monitors was recalculated based on the
most recent calibration experience.
35
-------
TABLE 9. RESULTS OF THF, BIAS DETERMINATIONS FOR THE CRMs
March 1994 (chamber at 18.4/18.3 pCi/L) June 1995 (chamber at 8.9/9.1 pCi/L ~)
CRM Rn Cone. (PCi/L) RE (%) CF Rn Cone. (pCi/L) Re (%) CF
FT395
ns
0.271
FT414
ns
0.269
FT538
ns
0.280
Py 3
16.5
-10
0.972
10.0
8
1.053
Py 4
19.1
5
1.114
9.8
7
1.188
FT172
16.2
-12
0.249
9.3
3
0.230
Mean/MARE
17.3
9
9.7
6
ns - data not supplied by the EPA.
Completeness-Of the greater than 28,000 half hourly indoor radon concentrations
measured with the six CRMs over the course of this study, almost 26,000 of these were
considered to be valid measurements, for a completeness rate of greater than the DQI goal of
90%.
Radon Grab Samples-
Precision—Over the course of this study, 15 grab samples were taken: 10 during the site
characterization and 5 during the slab crack measurements (one each at three cracks and two sub-
slab measurements). During this time period live sets of replicate measurements were made with
the scintillation cells used for these measurements. The CVs for these replicate measurements
were 10, 3, 9. 10, and 7% (all within the 10% DQI goal); so the precision of the grab samples
was considered acceptable.
Accuracy—During April 1993 when the site characterization measurements were being
made, and again in March 1994 after the slab crack measurements were taken in October 1993,
the grab sampling cells that used in these measurements were taken to the NAREL in
Montgomery. Alabama, for checks of their calibration. Air from one of the environmental
control chambers was sampled by each of the cells. They were returned to Birmingham where
they were counted at least twice. The average detected concentrations were calculated for each
cell using the most recently determined CF for that cell. Later NAREL sent the actual
concentration that was maintained in the chambers at the time of sampling. The relative error
(RE), expressed as a percent, was calculated. Then new CFs were calculated for each of the cells
based on the actual chamber concentrations. Table 10 lists the calibration results for these two
sets of calibration checks. As was the case with the CRMs, the measure that is used to compare
the REs is the MARE. The individual REs for the various cells ranged from -15 to 20%, with the
MAREs for the two calibration runs of 11 and 8%. All of these error measures were within the
DQI goal of ±25%; so the bias of the grab samples was considered to be acceptable.
36
-------
Before a cell was used in the field, a background count was generally made and recorded
to ensure that the cell was relatively "clean." After a sample was collected and counted, the cell
was flushed with clean ambient air and allowed to "relax" to allow the residual decay products to
decay away before another background check was made. With the relatively high radon
concentrations sampled in this study, especially, when taking soil and sub-slab samples, the cells
were subjected to large potentials for increased backgrounds.
TABLE 10. CALIBRATION RESULTS FOR THE GRAB CELLS FROM 1993 AND 1994
Cell No.
RE 93 (%)
CF93
RE94 (%)
CF94
EPA 1.2
-9
0.625
18
0.767
EPA 2.1
-9
0.616
6
0.655
EPA 2.4
3
0.713
-2
0.698
EPA 2.5
19
0.818
-7
0.765
SRI 283
12
0.889
-1
0.883
SRI 292
-5
0.779
9
0.845
SRI 293
-1
0.655
3
0.677
SRI 295
10
0.872
-15
0.740
SRI 296
12
0.858
-10
0.772
SRI 297
8
0.750
-5
0.715
SRI 300
19
0.838
-4
0.801
SRI 301
19
0.824
-9
0.673
SRI 501
20
1.490
-10
1.248
MARE
11
8
Completeness-All of the individual grab samples taken over the course of this study
produced valid measurements, for a 100% completion rate, easily exceeding the 90% DQI goal
for this measure of data quality.
Differential Pressure Measurements—
Precision-Before the pressure transmitters were placed in the building they were used to
measure seven pressures that spanned their ranges. CVs of 21, 21, 10, 18, and 12% were
calculated from the higher absolute pressures (5 to 25 Pa). The measurements of pressures
closest to zero had standard deviations of 1 to 2 Pa. These measures of precision (except for
measurements close to zero) were all within the 25% DQI goal; therefore, the precision of these
monitors was considered to be acceptable.
Accuracy-Digital micromanometers, which were routinely sent back to the manufacturer
for their calibrations to be certified with National Institute of Standards and Technology (MIST)
traceable test equipment, were used to calibrate the pressure transmitters. In late 1993, all three
micromanometers were so certified. After the building measurements were completed in late
37
-------
1994 and early 1995. the instruments were sent back to have the previous calibrations certified
again. All three instruments were checked over a ten-point pressure range, and at no pressure did
any of the three devices have a RE outside the ±1% range.
Before the building measurements began, the five pressure transmitters to be used were
calibrated with a micromanometer using seven pressures that spanned their ranges. These
measurements were made with the data acquisition system configured exactly as it was going to
be installed in the building; so that any bias introduced by a component of the system would be
corrected by the calibration procedure. As the transmitters were exposed to the known pressures,
they sent to the data logger corresponding DC voltages, which were recorded and stored.
Regressions were run over the pressure range measured, yielding slopes of pascals/volts and
intercepts of calculated pressures in pascals. A second measure was taken to control for another
type of bias that could be introduced over the course of the measurement period (zero drift of the
transmitters). For five minutes at the beginning of each half hour's measurements the pressure
signal sent to the transmitters was of zero pressure drop between the ports, and these readings
were recorded by the data logger. The calculations of the measured pressures each half hour
were made with this zero correction.
Completeness-During the period alter the instruments were fully installed and radon
measurements were taken (9/8/94 through 11/1/94), 2640 half hourly measurements were
possible with each of the five pressure transducers, or 13,200 in total. Over this period, 12.672
(representing 96.0%) were considered valid measurements, for a completeness rate of greater
than the DQI goal of 90%. In fact, of the 28,685 possible measurements before the instruments
were removed on 1/5/95, 26,136 (91.1%) were valid measurements, although the experimental
setup was largely unattended after mid-November.
Data Reviews
Prior to the study, all of the radon and pressure measuring equipment was calibrated as
described above. Generally QA personnel not directly involved with the actual field
measurements made the calibration checks of the equipment. Half of the CRMs and most of the
pressure transmitters came from the EPA, and one of their contractors performed the calibrations
and provided Southern with the results. The other half of the CRMs, the radon grab cells, and
the micromatiometers used to perform the pressure checks belonged to Southern. The calibration
checks for these radon measuring devices were performed at the EPA's NAREL in Montgomery,
Alabama, by Birmingham-based technicians and''or scientists. The calibration certification of the
micromanometers was performed by the manufacturer. The results of all the calibration checks
were reviewed by the project manager and the principal investigator and passed on to the on-site
project coordinator for use in the field. This individual kept detailed project logs, copies of
which were sent to Birmingham at least monthly. Here they were reviewed by both the manager
and principal investigator for completeness. At least twice during the project, a field visit was
made by Birmingham personnel to review the data set up and collection. Data reduction and
archiving were performed by the principal investigator; in preparation for reporting, the project
38
-------
manager conducted a data review of results from each instrument, verifying calibration constants
and data reduction equations for each device by comparison calculations.
Identification of Corrective Actions
The data from the data logger were retrieved within the next working day of any changes
to the system to ensure that their collection was complete and accurate as planned. If any data
appeared to be faulty or missing, then immediate checks of the system were performed. For
instance, if no data appeared in the output where some was expected, then the wiring and
connections were inspected. If unreasonable data were detected, then sampling lines were
checked for blockage, crimping, or leaks. Once the data retrieval appeared to be complete, then
downloads were conducted approximately weekly, and another thorough review of the collected
data was performed to ensure that the measurement and collection systems were operating as
planned. Because this was an occupied and working facility by the time the building was
completed, there were numerous potential interferences with consistent and continuous data
collection. Moreover, there were frequent thunder storms and severe weather that caused power
fluctuations. Generally the system was inspected as soon as possible after each such event
occurred.
REFERENCES
1. Pugh. T. D., Grondzik. W.T.. Scott, A., McDonough, S.F,., West, J., and White, T.R.,
Assessment of Concrete Floor Crack Frequency and Radon Flux, Revised May 1994,
School of Architecture, Institute ibr Building Sciences, Florida A&M University,
Tallahassee, FL, report to State of Florida, Department of Community Affairs,
Tallahassee, FL, FL-DCA Contract # 91RD-41-13-00-22-013.
2. Mcnetrez, M.Y., and Kulp, R.N'.. Radon Diagnostic Measurement Guidance For Large
Buildings. IJ. S. EPA Report to Florida Department of Community Affairs, on EPA
Contract No, 68D20062 WA 2/049. (In review)
3. U. S. Environmental Protection Agency. Indoor Radon and Radon decay Product
Measurement Device Protocols. HPA-402/R-92-004 (NT1S PB92-206176). Washington.
D.C., 1992. 104 pp.
4. U. S. Environmental Protection Agency, Radon Proficiency Program (RPP) Handbook.
EPA-402/R-95-013, Washington, D. C„ 1995. 120 pp.
39
-------
APPENDIX
Plots of the continuous data taken at the Mulberry Cogeneration building.
40
-------
40
30
20
aT
Q..
8 10
c
a>
®
^ 0
b
a>
5 -10
«
-------
Vi
!
<
"l
%J5
-u
08/25 08/27
08/26
08/29 08/31
08/28 08/30
Date
- DPU/Out EE Rm/Out Mech/Out
Recpt/Out ~ SS/Out
09/02
09/01 09/03
Figure A2. Time dependent Dp values at Mulberry Cogeneration Facility.
42
-------
H
bf"
\
Jp
09/02
09/04
09/03
09/05
09/06 09/08
09/07 09/09
Date
DPU/Out "~ EE Rm/Out Mech/Out
Reept/Out D SS/Out
09/10
09/11
Figure A3. Time dependent Dp values at Mulberry Cogeneration Facility.
43
-------
-40+
09/10
09/12
09/11
09/13
09/14 09/16
09/15 09/17
Date
DPU/Out ' EE Rm/Out Mech/Out
Recpt/Out SS/Out
09/18
09/19
Figure A4. Time dependent Dp values at Mulberry Cogeneration Facility.
44
-------
(8
Q-
d)
O
C
0)
w
0)
Q
d>
W
3
W
to
0)
Ih
-10
a.
-20
30
09/18
09/20
09/22
09/24
09/26
09/19 09/21 09/23 09/23 09/27
Date
DPU/Out EE Rm/Out Mech/Out
Recpt/Out G ¦ SS/Out
Figure A5. Time dependent Dp values at Mulberry Cogeneration Facility.
45
-------
09/26
09/28
09/27
09/29
09/30 10/02
10/01 10/03
Date
DPU/Out " EE Rm/Out Mech/Oul
Recpt/Out —E— SS/Out
10/04
10/05
Figure A6. Time dependent Dp values at Mulberry Cogeneration Facility.
46
-------
10/04 10/06 10/08 10/10 10/12
10/05 10/07 10/09 10/11
Date
~ DPU/Out EE Rm/Out Mech/Out
Recpt/Out ~ SS/Out
Figure A7. Time dependent Dp values at Mulberry Cogeneration Facility.
10/13
47
-------
40
30
-30
-40 H —-—H—
10/12 10/14 10/16 10/18 10/20
10/13 10/15 10/17 10/19 10/21
Date
DPU/Out —— EE Rm/Out Mech/Out
ReCpt/Out ~ SS/Out
Figure A8. Time dependent Dp values at Mulberry Cogeneration Facility.
48
-------
30
Q
CL
01
O
c
Q)
k.
S.'
0)
a
2
3
i0
w
2
-10
a.
-20
30
-40
10/20
10/22
10/28
10/24
10/26
10/21 10/23 10/25 10/27 10/29
Date
DPU/Out — ee Rm/Out Mech/Out
Recpt/Out ~ SS/Out
Figure A9. Time dependent Dp values at Mulberry Cogeneration Facility.
49
-------
10/28 10/30 11/01 11/03 11/05
10/29 10/31 11/02 11/04 11/06
Date
DPU/Out EE Rm/Out Mech/Out
Recpt/Out ~ SS/Out
Figure A10. Time dependent Dp values at Mulberry Cogeneration Facility.
50
-------
¦»-?¦¦¦% ^
i* wt
X v A
;
u
t
:
— **
V
;; ^
SW ifj **
^ W1 V
Jf-s;
15 j'i
s I:
f _
1
r
£ *
——#
K*
» • -"*ff?y-rr3
» tTtT* -
*vV. _ ^
WV
!
!
i
11/05 11/07 11/09 11/11 11/13
11/06 11/08 11/10 11/12 11/14
Date
DPU/Out — EE Rm/Out Mech/Out
Recpt/Out -9— SS/Out
Figure A11. Time dependent Dp values at Mulberry Cogeneration Facility.
51
-------
11/13 11/15 11/17 11/19 11/21
11/14 11/16 11/18 11/20 11/22
Date
DPU/Out EE Rm/Out Mech/Out
Recpt/Out ~ SS/Out
Figure A12. Time dependent Dp values at Mulberry Cogeneration Facility.
52
-------
a
x/'- £1 'i
^ V,
|Ryi
1
A
p
n JRSjS
w'
ru i ^
^ W-: ~'
¦M7* v
V
• i
• :
V • ;
: | v\
V
f
5
» i*
f * 1
N
«
11/21 11/23 11/25 11/27 11/29
11/22 11/24 11/26 11/28 11/30
Date
DPU/Out — EE Rm/Out Mech/Out
Recpt/Out ~ SS/Out
Figure A13. Time dependent Dp values at Mulberry Cogeneration Facility,
53
-------
40
30
20
(0
CL
-------
12/06 12/10 12/14 12/18
12/08 12/12 12/16 12/20
Date
DPU/Out EE Rm/Out Mech/Out
Recpt/Out ~ SS/Out
12/22
12/24
Figure A15. Time dependent Dp values at Muiberry Cogeneration Facility.
55
-------
t'
V'S
* ?
-
\ SE A, [
t
r
21
jZfJ
jBBf
Hr
——J
- *
t
'"V
*S3Bl^?5—
12/21 12/23 12/25 12/27
12/22 12/24 12/26 12/28
Date
DPU/Out EE Rm/Out Mech/Out
Recpt/Out -0— SS/Out
12/29
12/30
Figure A16, Time dependent Dp values at Mulberry Cogeneration Facility.
56
-------
ilar
/ >
. 'V/V
1 J
,:U
•s
iJ |
pffi I
b
(
4
i
K
1 - ; i
r4
•---i
'' v
v
J ;*:j
v '<
§ *»
12/28 12/30 0t/01 01/03
12/29 12/31 01/02 01/04
Date
DPU/Out " EE Rm/Out Mech/Out
Recpt/Out ~ SS/Out
01/05
01/06
Figure A17. Time dependent Dp values at Mulberry Cogeneration Facility,
57
-------
I
1
I
\:
l 1
i
j
I
ll I
ll
m
1
:: {
1
[a
ui
w
\J
:
I
%
08/17 08/19 08/21 08/23 08/25
08/18 08/20 08/22 08/24 08/26
Date
E.E.Rm
Control Rm Water Trmt. Recpt. Area
Figure A18. Time dependent Radon levels at Mulberry Cogeneration Facility.
58
-------
08/25 08/27 08/29 08/31 09/02
08/26 08/28 08/30 09/01 09/03
Date
E.E.Rm
Control Rm
Water Trmt.
Recpt. Area
Figure A19. Time dependent Radon levels at Mulberry Cogeneration Facility.
59
-------
|(i
1
ifiil 1
|1
im I i
h.
1
liil
1 :
if II f$
ilif
^nimi
1
m
I s y * i f
IP
0
09/02 09/04 09/06 09/08 09/10
09/03 09/05 09/07 09/09 09/11
Date
E.E.Rm
Control Rm Water Trmt.
Recpt. Area
Figure A20. Time dependent Radon levels at Mulberry Cogeneration Facility.
60
-------
10.0
9.0
8.0
7.0
O 6.0
a
09/10 09/12 09/14 09/16 09/18
09/11 09/13 09/13 09/17 09/19
Date
E.E.Rm --" Control Rm Water Trmt. Recpt. Area
Figure A21. Time dependent Radon levels at Mulberry Cogeneration Facility.
61
-------
10.0
9.0
8.0
7.0
3
O 6.0
Q.
C
09/18 09/20 09/22 09/24 09/26
09/19 09/21 09/23 09/25 09/27
Date
E.E.Rm Control Rm Water Trmt. —' Recpt. Area
Figure A22. Time dependent Radon levels at Mulberry Cogeneration Facility.
62
-------
10.0
9.0
8.0
7.0
3
O 6.0
Q.
c
•u I I I I I I I
09/26 09/28 09/30 10/02 10/04
09/27 09/29 10/01 10/03 10/05
Date
E.E.Rm Control Rm Water Trmt. " Recpt. Area
Figure A23. Time dependent Radon levels at Mulberry Cogeneration Facility.
63
-------
10/04 10/06 10/08 10/10 10/12
10/03 10/07 10/09 10/11 10/13
Date
E.E.Rm
Control Rm
Water Trmt. Recpt. Area
Figure A24. Time dependent Radon levels at Mulberry Cogeneration Facility.
64
-------
10/12 10/14 10/16 10/18 10/20
10/13 10/15 10/17 10/19 10/21
Date
E.E.Rm
Control Rm
Water Trmt. Reept Area
Figure A25. Time dependent Radon levels at Mulberry Cogeneration Facility.
65
-------
o
a
"5
>
©
C
o
"O
CO
~c
10/20 '10/22 10/24 10/26 10/28
10/21 10/23 10/25 10/27 10/29
Date . ' y
E.E.Rm
Control Rm Water Trmt.
Recpt. Area
Figure A26. Time dependent Radon levels at Mulberry Cogeneration Facility.
66
-------
10.0
9.0
8.0
7.0
O 6.0
Q.
10/28 10/30 11/01 11/03 11/05
10/29 10/31 11/02 11/04 11/06
Date
E.E.Rm ~~Control Rm - Water Trmt. Recpt. Area
Figure A27. Time dependent Radon levels at Mulberry Cogeneration Facility.
67
-------
ff
11/05 11/07 11/09 11/11 11/13
11/06 11/08 11/10 11/12 11/14
Date
E.E.Rm
Control Rm Water Trmt. Reept Area
Figure A28. Time dependent Radon levels at Mulberry Cogeneration Facility.
68
-------
11/13 11/15 11/17 11/19 11/21
11/14 11/16 11/18 11/20 11/22
Date
E.E.Rm
1 Control Rm
Water Trmt. Recpt. Area
Figure A29. Time dependent Radon levels at Mulberry Cogeneration Facility.
69
-------
11/21 11/23 11/25 11/27 11/29
11/22 11/24 11/26 11/28 11/30
Date
E.E.Rm
Control Rm
Water Trmt.
Recpt. Area
Figure A30. Time dependent Radon levels at Mulberry Cogeneration Facility.
70
-------
O 6.0
Q_
y
11/29 12/01 12/03 12/05 12/07
11/30 12/02 12/04 12/06
Date
12/08
E.E.Rm
Control Rm
Water Trmt. Reept. Area
Figure A31. Time dependent Radon levels at Mulberry Cogeneration Facility.
71
-------
12/06 12/10 12/14 12/18
12/08 12/12 12/16 12/20
Date
12/22
12/24
E.E.Rm
Control Rm
Water Trmt.
Recpt. Area
Figure A32. Time dependent Radon levels at Mulberry Cogeneration Facility.
72
-------
10.0
8.0
7.0
O 6.0
a
! i ] I I
12/21 12/23 12/25 12/27 12/29
12/22 12/24 12/26 12/28 12/30
Date
E.E.Rm Control Rm Water Trmt. """ Recpt Area
Figure A33. Time dependent Radon levels at Mulberry Cogeneration Facility.
73
-------
12/28 12/30 01/01 01/03 01/05
12/29 12/31 01/02 01/04 01/06
Date
E.E.Rm
Control Rm
Water Trmt.
Recpt. Area
Figure A34. Time dependent Radon levels at Mulberry Cogeneration Facility.
74
-------
bA
J.
i ,
f'jl . ft
HI ,
ft*
i
h'ya
ur |F
1 M
F ^
PiyLJ
W
f
\w
V
08/17 08/19
08/18 08/20
08/21
08/23
08/25
08/22
08/24
Date
Control Rm
Amb. Pmp
DPU Rm(Direct)
Subslab
DPU Rm
Recpt-Direct
08/26
Figure A35. Time dependent Radon levels at Mulberry Cogeneration Facility.
75
-------
1
I
ifwLjuiJy1
m
1 y
jl
A
ll
fw
*mw
'Tl -N \ ti Tfe 11
|: • r H * P
! Vf
i\
08/23 08/27
08/26
08/29 08/31
08/28 08/30 09/01
Date
09/02
09/03
Control Rm
Amb. Pmp
DPU Rm(Direct)
Subslab
DPU Rm
Recpl-Direct
Figure A36. Time dependent Radon levels at Mulberry Cogeneration Facility.
76
-------
i
L
I
A
!¦
i-
to i
I,!
~f
¥ I JLI
1 *
W
i
09/02
09/03
09/04
09/05
Control Rm
Amb. Pmp
09/06
09/07
Date
09/08
09/10
09/09
09/11
DPU Rm(Direct)
Subslab
DPU Rm
R«cpt-Direct
Figure A37. Time dependent Radon levels at Mulberry Cogeneration Facility.
77
-------
10.0
15000
9.0
-14000
8.0
-13000 -J
7.0
a.
-12000 o>
_l
o 6.0
5.0
11000
O 4.0
"D
©
£E
3.0
-10000 _q
-9000
2.0
-8000
1.0
0.0
•7000
09/10
09/12
09/14
09/1S
09/18
09/11 09/13 09/15 09/17 09/19
Date
Control Rm DPU Rm(Direct) - DPU Rm
Amb. Prop Subslab Recpt-Direct
Figure A38. Time dependent Radon levels at Mulberry Cogeneration Facility.
78
-------
''ii
-
"
; S
1 ¦>
,, ii
wii5
t,
.
a>
>
_J
-11000
C
o
T3
0
oc
-10000
XI
CO
c0
Si
-9000
Z3
C/3
•8000
7000
09/19
09/21
Control Rm
Amb. Pmp
09/23
Date
09/25
09/27
DPU Rm( Direct)
Subslab
DPU Rm
Recpt-Direct
Figure A39. Time dependent Radon levels at Muiberry Cogeneration Facility.
79
-------
15000
10.0
9.0
-14000
8.0
-13000 -J
7.0
,_J
O 6.0
a.
-12000 W
_l
11000 C
>
0)
_J
s.o
O 4.0
•D
(0
DC
3.0
-10000 _q
-9000
2.0
-8000
1.0
0.0
¦7000
09/26
09/28
10/04
09/30
10/02
09/27 09/29 10/01 10/03 10/05
Date
Control Rm DPU Rm(Direct) DPU Rm
Amb. Pmp Subslob ...... Recpt-Direct
Figure A40. Time dependent Radon levels at Mulberry Cogeneration Facility.
80
-------
•
J ,
ji
k k
•J?;,
'
IM
lap-
i jv-jfy i
v.' ?
®w
l*. f-4.;
to
10/04
10/06
10/08
10/10
10/12
•15000
14000
-13000 J
O
Q.
•12000 w
§!
•11000
-10000
9000
c
o
•X3
<3
DC
D
tn
-Q
3
CO
-8000
¦7000
10/05
10/07
Control Rrn
Amb. Pmp
10/09
10/11
10/13
Date
— DPU Rm(Direct)
Subslab
DPU Rm
R«cpt-Direct
Figure A41. Time dependent Radon levels at Mulberry Cogeneration Facility.
81
-------
IrWrfW. ,,I|V
t.
<
I
l/:-
\
u
[\
$
J j
* J
(4
Jl
W!i _
J . i
& j
M
fl t;
In
i\
w
1? lif *^
L
J:;
IS ^hs} '¦
f ijrl
' fwr#y
• ? 4
w
10/12 10/14 10/16 10/18 10/20
10/13 10/15 10/17 10/19
Date
Control Rm
Amb. Pmp
DPU Rm(Direct)
Subs lab
DPU Rm
Recpt-Direct
-15000
•14000
-13000
O
a
12000 «
U
3
11000
10000
¦9000
c
o
"O
®
oc
CO
Si
3
C/3
-8000
¦7000
10/21
Figure A42. Time dependent Radon levels at Mulberry Cogeneration Facility.
82
-------
-
-
_
1
r
Am
X
%
%
V
ij
\
4
—
<
JI
n i.
I
£
L: It
: .4
1 1
!?!
Si =
i =
£
t"
ft
9:
! 1:
'i j i
1 i
» :s :: 5
f W 1
!i ,
i * r 1
l
t ?,
y*
V
d'il*
r%s
I
: ; /
:<>*
f*
fj * "?j i
. if'v
10/20 10/22 10/24 10/26
10/21 10/23 10/25 10/27
Date
10/28
¦13000
-14000
13000 J
O
a.
12000 JJ
¦11000
-10000
-9000
o
TJ
<0
cc
X!
J2
0
_Q
3
CO
8000
7000
10/29
Control Rm
Amb. Pmp
— DPU Rm(Direct)
— Subslab
DPU Rm
Recpt-Direct
Figure A43. Time dependent Radon levels at Mulberry Cogeneration Facility.
83
-------
-
-
_
sw«P*V
,
""
n
1
h
m i
III 1
% ,
jrt
A ,
ii- j
; »:fc;:• •
i fh
if*
S?_: I
fV
I
' W
V V*1*
-v'*
10/28
10/30 11/01 11/03 11/05
10/29 10/31 11/02 11/04
Date
Control Rm
1 DPU Rm(Direct)
Subslab
DPU Rm
— Recpt-Direct
•15000
-14000
-13000
-12000 »
<0
>
3
o
Q_
¦11000
¦10000
c
o
<0
cc
-Q
<0
M
Si
3
8000
¦7000
11/06
— Amb. Pmp
Figure A44. Time dependent Radon levels at Mulberry Cogeneration Facility.
84
-------
i
Wi»
01
li
ilk
j i
jlj
; ;
f\
|
i
ui
*1 ,!
m ; ^
>/,.
' o
*
/'
!
f
ffrf y*
f a,fi/i
11/05 11/07 11/09
11/06 11/08 11/10
Date
11/11
11/13
11/12
Control Rm
Amb. Pmp .
DPU Rm(Direct)
Subslab
DPU Rm
Recpt-Direct
-12000 »
3
¦15000
-14000
-13000
o
a.
11000
-10000
¦9000
c
o
"U
«
oc
Si
JO
CO
.Q
3
CO
h8000
¦7000
11/14
Figure A45. Time dependent Radon levels at Mulberry Cogeneration Facility.
85
-------
1
•,?v J
3
Jl x: ,
£ *
SM .
'¦ "4*?.*
; c
11/13 11/13 11/17 11/19 11/21
11/14 11/16 11/18 11/20
Date
¦15000
-14000
13000 -J
O
a.
-12000 J2
Q>
¦11000
-10000
¦9000
c
o
"D
(C
OC
A
J5
w
A
3
CO
-8000
¦7000
11/22
Control Rm
Amb. Pmp
DPU Rm(Direct)
Subs lab
•• DPU Rm
"¦ Recpt-Direct
Figure A46. Time dependent Radon levels at Mulberry Cogeneration Facility.
86
-------
o
Q_
Q)
>
>
3
¦11000
10000
9000
8000
o
T5
00
CC
Ui
.a
u
CO
¦7000
11/30
Figure A47. Time dependent Radon levels at Mulberry Cogeneration Facility.
87
-------
¦V
J
1
(
li
i s
i
§
iii
r i
: i
c :
1 ! 1
f \ F"
| j
% .*
3
1 *=
J if •
%? ill i
/U
f u«^-
; \ 13
=' %i->
• £
'V/l
11/29 12/01 12/03 12/05 12/07
11/30 12/02 12/04 12/06
Date
12/08
Control Rm
Amb. Pmp
DPU Rm(Direct)
Subslab
DPU Rm
Recpt-Direct
Figure A48. Time dependent Radon levels at Mulberry Cogeneration Facility.
88
-------
-
-
4
-
—
k
\
m
ft* 1X1
I
It
12/06 12/10 12/14 12/18 12/22
12/08 12/12 12/16 12/20
Date
•15000
-14000
-13000
o
a
•12000 «
£
3
11000
r10000
-9000
•8000
c
o
TJ
cc
_Q
«
.a
3
C/D
•7000
12/24
Control Rm
Amb. Pmp
DPU Rm(Dir#ct)
Subslab
DPU Rm
Recpt- Direct
Figure A49. Time dependent Radon levels at Mulberry Cogeneration Facility.
89
-------
-
-
A
¦
t
.
J
, Mi, '
c
3
0i..
f-
fs fS
M% i
¦ %
rfW
k. ¦ VvV »i
U : ¦
t *
Vw
15000
-14000
h13000
O
3.
12000 w
ai
>
a>
¦11000
10000
9000
c
o
TJ
(0
£E
Si
a
W
.Q
3
CO
-8000
7000
12/21 12/23 12/23
12/22 12/24 12/26
Date
12/27 12/29
12/28 12/30
Control Rm
Amb. Pmp
DPU Rm(Direct)
Subelab
DPU Rm
Recpt-Direct
Figure A50. Time dependent Radon levels at Mulberry Cogeneration Facility.
90
-------
-
2
-
3 ?
I {
i'1
L
(j
!§
f-i*
Fi;j
:
:
:
\
M
i
ii *
Hi ¦?'
i,
r iwv
: r J
*j§ \ .5
» : 1 9 h
¦ W
r%W
fjj.
"f i.
Kii
15000
-14000
13000
•12000
11000
-10000
¦9000
8000
o
Q-
<1)
>
.5
C
o
¦O
«0
oc
J9
o)
X!
3
CO
7000
12/28 12/30 01/01 01/03 01/05
12/29 12/31 01/02 01/04 01/06
Date
Control Rm
Amb. Pmp
DPU Rm(Direct)
Subslab
DPU Rm
Recpt Direct
Figure A51. Time dependent Radon levels at Mulberry Cogeneration Facility.
91
-------
j
k
1A
\
v A
V
i
V \
I
\f\
7J
>
h\
tV¥
08/17 08/19 08/21 08/23 08/25
08/18 08/20 08/22 08/24 08/26
Date
Tpanel
Pressure
Figure A52. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
92
-------
85-
7*
V
V
tv\
\i
r1
i
i
65-
\i
r
r !
V
08/25 08/27 08/29 08/31 09/02
08/26 08/28 08/30 09/01 09/03
Date
Tpanel — Pressure
Figure A53. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
93
-------
85'
'Vj
r
h
09/02 09/04 09/06 09/08 09/10
09/03 09/05 09/07 09/09 09/11
Date
Tpanef
Pressure
Figure A54. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
94
-------
V
s/\/
w
vV
lA/
,fA4
h
- ft r
1/
J\
i
V
f
y
w
if
i
-30.5
-30.4
-30.3
-30.2
TO
X
Q)
-30.1
3
W
W
0)
-30
k-
CL
O
-29.9
(V
E
o
-29.8
<0
CQ
-29.7
-29.6
-29.5
09/10 09/12 09/14 09/16 09/18
09/11 09/13 09/15 09/17 09/19
Date
Tpanel
Pressure
Figure A55. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
95
-------
I
V/
j-
"Ay
vV
w
sxl
V1
r
A
\ /V
r~
r
lA
/
j
Iv
VJ
09/18 09/20 09/22
09/19 09/21 09/23
Date
t-30.5
-30.4
-30.3
-30.2
O)
I
a>
-30.1
w
3
CO
CO
0)
-30
Q.
o
-29.9
a>
£
e
-29.8
<3
m
29.7
-29.6
-29.5
Tpanel
09/24
Pressure
09/26
09/25 09/27
Figure A56, Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
96
-------
30.5
-30.4
-30.3
-30.2 4?
U_
O
-30.1
3
30
0)
a
£
m
i-
-29.9
-29.8 (0
P29.7
¦29.6
-29.5
09/28
09/30
10/02
10/04
09/26
09/27 09/29 10/01 10/03 10/05
Date
Tpanel — Pressure
Figure A57. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
97
-------
V/
vV
TV
A/
w
vV
A
V f
V f
/Uj
\rA
M
\J
10/04 10/06 10/08 10/10 10/12
10/05 10/07 10/09 10/11 10/13
Date
Tpanel
Pressure
Figure A58. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility,
98
-------
83-
80-
73
70-
-
-V
vV
s/ ¦
a!
^ j
I
!\
\f
X
V
iv/
V/
\!
_
(
65
10/12 10/14 10/16 10/18 10/20
10/13 10/15 10/17 10/19 10/21
Date
~ Tpanel Pressure
Figure A59. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
99
-------
V,
w
A;
A/
V
v/
v/1
A
""A
<:
?
V
V
nl
u \
i
•vf
V
li
10/20 10/22 10/24 10/26 10/28
10/21 10/23 10/25 10/27 10/29
Date
Tpanel
Pressure
Figure A60. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
100
-------
AP
v\ ,
K/
w
v V
II
t
V
¦it
]TA
_A
1
jV
Ih
/
f
Y>
10/28 10/30 11/01 11/03 11/05
10/29 10/31 11/02 11/04 11/06
Date
Tpanel Pressure
Figure A61. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
101
-------
•30.5
-30.4
-30.3
-30.2 4?
-30.1
-29.9
-29.8 (0
70-
-29.7
-29.6
29.5
65
11/05
11/13
11/11
11/09
11/07
11/06 11/08 11/10 11/12 11/14
Date
Tpanel —Pressure
Figure A62. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
102
-------
w
v
11/13 11/15 11/17 11/19 11/21
11/14 11/16 11/18 11/20 11/22
Date
Tpane I —— Pressure
Figure A63. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
103
-------
30.5
-30.4
-30.3
30.2
U.
O
-30.1
ffl
k_
2
2
©
a
£
©
t-
-29.9
-29.8 as
-29.7
-29.6
65
11/21
--29.5
11/25
11/29
11/23
11/27
11/22 11/24 11/26 11/28 11/30
Date
—Tpanel — Pressure
Figure A64. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
104
-------
A j
\,A /
wV
A
A i
d
vA /
\
A/
¦v V
V
¦A/
W
V
\
A
f
\
r
V
V
iw
/
V
11/29 12/01 12/03 12/05 12/07
11/30 12/02 12/04 12/06 12/08
Date
Tpanel Pressure
Figure A65. Time dependent Temperature arid Barometric Pressure levels at
Mulberry Cogeneration Facility.
105
-------
AJ
A
jv
\r 1/
V
Am
i/
Vi
,L
*
V
' V
\j ir
vJ v 1
12/06 12/10 12/14 12/18 12/22
12/08 12/12 12/16 12/20 12/24
Date
Tpanel — Pressure
Figure A66. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
106
-------
•30.5
-30.4
-30.3
-30.2 4?
U_
O,
-30.1
0)
3
<1)
Cl
E
0)
\—
29 9
-29.8 w
70
-29.7
-29.6
29.5
12/29
12/27
12/23
12/25
12/21
12/22 12/24 12/26 12/28 12/30
Date
Tpanel ~~" Pressure
Figure A67. Time dependent Temperature and Barometric Pressure levels at
Mulberry Cogeneration Facility.
107
-------
A /
l A r
N
^\}
\f]/
J
V
W
------- |