EPA/ESD/R10-95/118
August 1995
EPA Superfund
Explanation of Significant
Differences for the
Record of Decision:
Idaho National Engineering Laboratory
(USDOE), Pit 9 (OU 7-10),
Idaho Falls, ID
1/26/95
-------
EXPLANATION OF SIGNIFICANT DIFFERENCES
FOR THE PIT 9 INTERIM ACTION
RECORD OF DECISION
AT THE RADIOACTIVE WASTE MANAGEMENT COMPLEX
IDAHO NATIONAL ENGINEERING LABORATORY
I. INTRODUCTION
This document is an Explanation of Significant Differences (ESD) from the Record of Decision
(ROD) for the Pit 9 Interim Action, signed by the United States Department of Energy, United States
Environmental Protection Agency, and State of Idaho Department of Health and Welfare (the
Agencies), effective October 1, 1993, in accordance with the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) as amended by the Superfund Amendments
and Reauthorization Act, and to the extent practicable, the National Oil and Hazardous Substance
Pollution Contingency Plan. This ESD is also prepared in accordance with the terms of the Federal
Facility Agreement and Consent Order.
Site Name and Location
Pit 9, Subsurface Disposal Area, Radioactive Waste Management Complex
Waste Area Group 7, Operable Unit 7-10
Idaho National Engineering Laboratory (INEL)
The lead agency for this action is the United States Department of Energy Idaho Operations Office
(DOE-ID). The United States Environmental Protection Agency and the State of Idaho Department
of Health and Welfare (IDHW) both concur with, and approve the need for, this significant change to
the selected remedy. The Agencies participated jointly in preparing this document.
Need and Purpose for an Explanation of Significant Differences
This ESD was prepared in accordance with Section 117(c) of the CERCLA, and 40 CFR
300.435(c)(2)(i) which requires that an ESD be published "when the differences in the remedial or
enforcement action, settlement, or consent decree significantly change but do not fundamentally alter
the remedy selected in the ROD with respect to scope, performance, or cost." Accordingly, this
explanation addresses cost estimates that increased significantly for the selected remedy identified in
the Pit 9 ROD and is implemented to: Present revised project cost estimates, including additional
costs identified in the firm fixed-price subcontract for the operations and maintenance and capital cost
elements.
A detailed comparison of the current cost estimate information with that presented in the ROD is
presented in Section DDL
This and other relevant documents will become part of the Administrative Record file pursuant to 40
CFR 300.825(a)(2). Copies of this ESD and the Pit 9 Administrative Record are available to the
public in the INEL Information Repository sections of the libraries and-offices listed on the last page
of this Explanation of Significant Differences.
January 18,1995 1
-------
n. SITE HISTORY, CONTAMINATION PROBLEMS, AND SELECTED REMEDY
The INEL is located 32 miles west of Idaho Falls in southeastern Idaho and encompasses
approximately 890 square miles of semi-arid desert overlying the Snake River Plain Aquifer. The
Subsurface Disposal Area is located at the Radioactive Waste Management Complex, which is
located in the southwest portion of INEL (see Figure 1). The area of focus is Pit 9 which is located
in the northeast corner of the Subsurface Disposal Area. Pit 9 is designated as Operable Unit 7-10
and is scheduled as an interim action in the Action Plan of the Federal Facility Agreement and
Consent Order.
Pit 9 was operated as a waste disposal pit from November, 1967 to June, 1969. It was used to
dispose of approximately 110,000 cubic feet (3,114.8 cubic meters) of transuranic waste (as defined
in 1969, > 10 nCi/g) from the Rocky Flats Plant and additional low-level wastes (as defined in 1969,
< 10 nCi/g) from waste generators located at the INEL. The total volume of the pit is approximately
250,000 cubic feet (7,079.2 cubic meters) of overburden, 150,000 cubic feet (4,247.5 cubic meters)
of packaged waste, and 350,000 cubic feet (9,910.9 cubic meters) of soil between and below the
buried waste. Most of the transuranic waste consists of drums of sludge (contaminated with a
mixture of transuranic waste and organic solvents), drums of assorted solid waste, and cardboard
boxes containing empty contaminated drums.
The National Contingency Plan expresses a preference for early response action where such action
will expedite completion of total site cleanup. The Federal Facility Agreement and Consent Order
incorporates that preference. The Pit 9 Interim Action is intended to remove the source of
contamination to a level that is protective of human health and the environment, to expedite overall
cleanup at the Radioactive Waste Management Complex, .and to reduce risks associated with potential
migration of hazardous substances to the Snake River Plain Aquifer. The cleanup will also provide
information regarding technologies potentially applicable to remediation of similar waste types at the
Radioactive Waste Management Complex.
Two proposed plans for remediating Pit 9 were presented to the public: the first in December of
1991 and the second in October of 1992. The Revised Proposed Plan contained details of processes
that could be used in association with the preferred alternative that the public had requested during
public meetings for the first Proposed Plan. The Agencies' preferred alternative was physical
separation/chemicalextraction/stabilization of contaminants in Pit 9. The preferred alternative will
stabilize contaminants after physical separation and chemical extraction to minimize migration of
contaminants and to achieve reduction in waste volume and risk.
Following review of public comments, the preferred alternative described in the two proposed plans
was selected by the Agencies. The selected remedy was documented in the Pit 9 ROD which was
signed by the Department of Energy, the Environmental Protection Agency, and the State of Idaho
Department of Health and Welfare on October 1, 1993.
January 18.1995
-------
I NEL,
~ RWIIC
Dote Drown: Jonuory 17. 1995
u1 18 rwmc: rwmc.brent2
, F i 9 u r e 1. P i l 9 i nth e R, a d i 0 a c li v e
. .
~ --'.,
--", ........, 'I ,:
-- . "- ........
Adm i Ii I sir 0 I i v eAr eo, r~ (/ . - -. .-- ::>.
/.""--.- ~~ /
t . --"I-I-- ....... J ""~--'--....
- . -~~., - r' 0/- /
P ~ tfl/;j~~-_.--
. .t--'---"-'~'---'"
..-.--.--- ,---.--,,,..,
'.
Subsurface Disposal Area
[\H.
-----=.
~"
':::::::
''''''''':::---'''''
-.~
--........:-
'-.......:::::
Tronsuronic Sioroge Arca
'~' j
'. '---.... " j
........
............. .
'..........
,~
Waste Management Complex Subsurlacc
c-.----. j
L-.. -,--= ._- "'1__. - ---
o 500 1000 1500 r ccf
U i s P 0 S II I ,\ r (~ Q
3
-------
. .
Under the .selected remedy of physical separation/chemical extraction/stabilization, Pit 9 will be
remotely excavated in a double-contained structure built over the pit Contaminated materials
requiring treatment will be physically separated into waste streams. Waste streams, such.as
contaminated soil, . will be separated from waste containers disposed in the pit, and then "each waste
stream will be placed in the appropriate waste processing units. Additional physical separation will
occur usi,?-g mechanical methods such as flotation, gravity cOncentration, sedimentation, and filtration
to separate mixtures of solids and contaminants. In" addition, chemical extraction processes will be
used to remove contaminants. The objectiv.e of the separati.on technology will be to r~move organic
contaminants and concentrate radioactive contaminants and heavy metals to reduce the volume of
waste requiring disposaL The selected remedy also includes a stabilization process using thermal
treatment. Detailed information concerning the selected remedy can be found in the ROD for Pit 9.
Because some aspects of the remedial technologies had not been proven on radioactively
. contaminated hazardous waste sites like ~it 9, implementation of the preferred remedial alternative is
contingent on successful demonstration that the cleanup criteria and other performance objectives
could be met in Proof-of-Process and Limited Production Test phases. The Proof-Of-Process Tests
were completed by two subcontractor teams, Lockheed Environmental Systems and Technologies
Company (LESAT) and Waste Management Environmental Services (WMES), in December, 1993.
" "
Based on the Proof-of-Process Tests and a competitive bidding process, LESAT was selected by an
EG&G Idaho Source Evaluation Board ~o remediate Pit 9. The preliminary (30%) design process has
been recently Completed, and the remainder of the remedial design activity is scheduled to be
completed by March, 1996. The Limited Production Test is currently scheduled to be started in
August, 1996. "
ID. DESCRIPTION OF SIGNIFICANT DIFFERENCES AND BASIS
Remediation of Pit 9 will be completed using the preferred alternative described in the ROD. The
overall waste management approach to be used by LESA T is also consistent with that presented in
the ROD. The significant change that necessitated preparation of this ESD relates exclusively to
unanticipated cost increases. The costs in the negotiated fixed-price subcontract significantly.
exceeded estimated project costs presented in the ROD. Because the magnitude of the change
exceeds that typically expected for CERCLA actions, the Agencies prepared this ESD as' notification
of the change.
Table 1 presents the preliminary estimated costs as presented in the Pit 9 ROD along with revised
costs which are based on current information. Since this Pit 9 operation is a first of a kind facility
and operation, much uncertainty existed when the initial estimate was prepared. The Pit 9 ROD Cost
estimates did not include allowances for project management, contingency, profit, or escalation and
underestimat~ the capital as well as operation and maintenance costs.
The revised costs presented in Table' 1 reflect the fmal contract price for the proof of proceSs test
phase and the actual contract price established in the firm fixed-price contract with LESAT resulting
from the competitive procurement process for the cleanup. The $185.6 million subtotal in Table 1
for Interim Activity includes $178.6 million for fixed-price subcontract costs for the subcontractor to
January 18, 1995
4
-------
4 .
.,install and operate the Pit 9 facility, as well as approximately $7.0 million for'prelimi~ary design and
safety analys.is activities previously conducted by both subcontractors. The estimate for long term
storage and offsite disposal has not ebanged.' .
The firm fixed price contract established the cost to the Government for the total retrieval and
treatment of the Pit 9 waste. An advantage of the fixed-price subcontracting approach being
implemented for the Pit 9 project is that the $178.6 million subcontract cost can only change if major
project assumptions change. The contract also detailed the price of the major activities to be
performed under the contract such as design, nuclear safety analysis and facility startup, equipment
and facilities, unit pricing for material processed, decontamination and decommissioning costs, and
profit. Significant differences existed. between the original ROD estimates and the contract price in .
most cases.' .
The fix~d price contract included a 15% profit which amounted to a total of $23.3 million. This
profit is included in the revised cost numbers discussed below and included in Table I for the capital
and operations and maintenance costs. The profit was evenly applied to all capital and operations
and maintenance costs although no profit will actually be paid until successful completion of the
limited production test. Since there was no. allowaQce for profit in the original estimate, this
represents a significant fraction' of the change in cost. Because it is a fixed-price contract, the
allowances, for contingency and escalation inCluded in the contract price by LESA T are unknown.
These may represent a significant increase over the ROD cost estimate. Any allowances for
contingency and escalation would have been included within the contract price for each specific
activity (e.g., design, equipment). The contingency allowance is believed to be significant because
this is a first-of-a-kind facility and because of the unknowns associated with the pit inventories and
retrieval and treatment system performance. Design and operational costs of prototype activities like
Pit 9 are typically much higher than the cost of proven technologies and systems.
For operations arid maintenance costs, the ROD estimate was $29.1 million while the contract price
was $76.1 million. The ROD estimate was based on treatment of 150,000 cubic feet of material (at
a cost of $22.1 million), while the contract price is based on treating 250,000 cubic feet of material
(at a cost of $64.8 million). If should be noted that the 250,000 cubic feet of material requIring
treatment identified in the contract is considered a maximum. If the quantity differs from 250,000
cubic feet, the cost of the remediation may decrease or increase accordingly. The ROD estimate was
also based on the removal of 270,000 cubic feet of the soil cover and material not requiring treatment
(at a cost of $60,000), while the contract price is based on 500,000 cubic feet of this material (at a
cost of $5.6 million). The contract price includes sampling, analysis and handling of this material
while the ROD estimate assumed this material was clean and no analysis or additional handling
would be required. The ROD estimate assumed the facility would be required to operate 5 days a
week (40 hours/week) for a year period to complete the LPT and full scale remediation while the
fixed price contract is based on a 24 hour per day, five day per week operation for 16 months to
complete LPT and full scale remediation. This difference in operating strategy, although not
qUantified, is expected to contribute significantly to the cost increase. , Facility decontamination and
removal costs were estimated iIi the ROP to be approximately $6.9 million while the contract price is
$4.8 million. The ROD estimate also did not include some miscellaneous costs under the operations
and- maintenance category which the contract included at a price of approximately $900,000.
January 18, 1995
5
-------
, .
~ t
For capital costs, the estimate in the ROD was $20,7 million while the revised cost ar:nount.was" "
$109.5 mil.lion. Under this category, the. estimate for design was $3.4 million while the d~ign costs
to date plus the contract price is $56.8'million. This extremely large discrepancy is attributed
primarily to funding two design teams at a cost of $7 million until a contract selection was made and
the final contract price ($49.8 million) which included costs for off site full scale test facilities to
provide design data and to be used in the real time resolution of operational issues in an
uncontaminated environment during the Pit 9 project. Under the original project estimate and
assumptions, the need for off site test facilities was not envisioned, therefore there was no cost
allowance for offsite test facilities in the estimate. The remaining capital costs associated with
buildings and equipment was estimated at $17.3 ~illion for the ROD while the contract price was
$52.7 million. This cost difference is believed to be influenced primarily by the complexity of
integrating the various facilities and components, a more extensive use of remotely operated systems,
and more rigorous containment structures than was envisioned in the ROD estimate.
In summary, building design and construction required considerable modification from the original
ROD estimate. In particular, storage requirements for chemicals used in the process, physical
separation equipment, control requirements for the plasma-arc furnace, chemical extraction processing
systems, air emissions controls, and engineering requirements for the containment structure have been
col1$iderably refined from the original estimates which were baSed on" conceptual design information;
therefore, costs are now better defined.
Table 1. Interim Action cost estimate (millions or dollars).
Description
Proof-of-Process Test
ROD Costs8
Revised Cost
Subtotal
$16.0
$ 16.4b
Interim Activity
Capital
Operations and "Maintenance
Subtotal
20.7
29.1
109.5
76.1
49.8
185.6
Long-Term Storage and Off-Site Disposal
Subtotal
Total
62.0
127.8
62.0
264.0
a.. ROD costs rounded to nearest one-tenth of a million dollars
b. Actual costs for Proof-of-Process Tests
January 18, 1995
6
-------
. .
-
..
..
IV. AFFfRMA TION OF THE STATUTORY DETERMJNA TION
As presented in the ROD, each alternative evaluated (in situ-vitrification; ex-situ vitrification: the
selected remedy; and complete removal, storage, and off-site disposal) would provide adequate
overall protection of human health and the environment by minimizing potential contaminant
migration from Pit 9. The alternatives would also cOmply with the Applicable or Relevant and
Appropriate Requirements of Federal and State laws and regulations. identified in the ROD. The
foHowing: discussion affirms that the selected remedy continues to provide the best balance of trade-
offs in terms of long-term effectiveness, reducing toxicity, mobility and volume of the contaminants,
implementability, short-term effectiveness, and cost.
The selected remedy; as well as the ex,.situvitrification alternative' presented in the ROD, both use a
stabilization component to immobilize the contaminants, thereby achieving some degree of long-term
effectiveness. The selected remedy provides a greater degree of reduction of waste volume before
stabilization via the physical/chemical treatment process so that the amount of waste requiring
monitoring during storage and ultimately requiring disposal will be gi-eatly reduced. The reduced
volume of waSte requiring long-term monitoring, storage, and disposal increases the overall long-term
effectiveness of the selected alternative in' comparison to ex-situ vitrification and the complete
removal, storage, and off-site disposal option.
At the time of the ROD, the early developmental stage of the in-situ vitrification process limited the
ability of the Agencies to determine the efficiency and long-term effectiveness of the process on the
heterogeneous wastes found in Pit 9. Continuing uncertainties associated with the effectiveness of in-
situ vitrification include its effectiveness on heterogeneous materiais such as .those in Pit 9 and the'
ability to confirm complete vitrification/stabilization of the pit contents. The soil at the RWMC lacks
some' of the glass-rorming materials such as silica and aluminum oxide that are necessary for efficient
vitrification. It may be difficult to control subsurface and surface migration of the vaporized volatile
organics that are present in significant amounts in Pit 9 wastes. In. addItion, the presence of a large
volume of metallic objects within the pit may result in arcing between the electrodes and in
incomplete vitiification. It is presently estimated that the in-situ Vitrification alternative requires
several more years of development before being available for use in an application such as the Pit 9
Interim Action. .
The selected. remedy remains superior to all alternatives evaluated with respect to implementability
. and/or volume reduction; therefore, the ability to achieve ROD remedial action objectives is best for
the selected remedy. .
. .
The selected remedy would provide overall effectiveness proportional to its costs. The Agencies
have concluded that the relative cost comparisons are basically unchanged from that presented in the
ROD. Considering the revised cost estimates, the Agencies believe that the selected remedy remains
protective of human health and the environment, complies with FeCleral and State requirements that
are applicable or relevant and appropriate to this remedial action, and is cost-effective. In addition,
the selected remedy meets the stattItory requirements to use permanent solutions and treatment
technologies to the maximum. extent possible. The Agenc~es prefer a potentiai permanent'solution
whenever possible and, in the case of Pit 9, the goal is to meet the objectives of an .interim action
and provide a potentially permanent treatment solutioD- .
January 18, 1995
7
-------
V. PUBLIC PARTICIPATION ACTIVITIES
A notice publishing the availability of this ESD has been placed in the Post Register - Idaho Falls,
Idaho State Journal - Pocatelio, Times-News - Twin Falls, Southern Idaho Press - Burley, Idaho
Statesman - Boise, Lewiston Morning Tribune - Lewiston, and Daily News - Moscow. Consistent
with Section 300.43 5(c)(2)(i) of the National Contingency Plan, this ESD has been placed in the
Administrative Record Section of the INEL Information Repositories listed below upon publication of.
the Notice of Availability. A postcard announcing the availability of this ESD was sent to the INEL
mailing list participants. This ESD and the contents of the Pit 9 Administrative Record are available
for public review. In addition to the Administrative Record on file for the ROD, the Administrative
Record for this action includes a copy of this ESD and relevant newspaper notices associated with the
explanation (refer to the binder for OU 7-10): Additional supporting information on current Pit 9
project activities is included in the INEL Information Repositories.
The revised cost of the selected remedy does not represent a fundamental change
from that contained in the ROD, and therefore, a formal comment period is not required. Additional
information or briefings may be requested
by contacting the office listed below or calling the toll-free number for the
INEL at (800) 708-2680:
Reuel Smith
INEL Community Relations Plan Office
P.O. Box 2047
Idaho Falls, Idaho 83403-2047
(208) 526-6864
LIBRARIES AND OFFICES CONTAINING INFORMATION REPOSITORIES
DOE Reading Room
INEL Technical Library
1776 Science Center Drive
Idaho Falls, Idaho
INEL Boise Office
816 West Bannock
Suite 360
Boise, Idaho
INEL Pocatelio Office
1651 Al Ricken Drive
Pocatelio, Idaho
University of Idaho Library
U of I Campus
Moscow, Idaho
INEL Twin Falls Office-
233 Second Street North,
Suite B
Twin Falls, Idaho
Shoshone-Bannock Library
HRDC Building
Bannock and Pima Streets
Fort Hall, Taaho
January 18,1995
-------
Site Name:
EXPLANATION OF SIGNIFICANT DIFFERENCES
Concurrence
Idaho National Engineering Laboratory
Pit 9 (OU 7-10) Interim Remedial Action
INITIAL
i
NAME
Nearman
Pierre
Oesterle
, -7—» •> ,
!Gearheard !Smith
^!Clarke
DATE
RPM
Sed.Chief
ORC
Br. Chief Divt. D'ir. f RA
------- |