oEPA
United States Eastern Environmental EPA 520/5-87-008
Environmental Protection Radiation Facility June 1987
Agency 1890 Federal Drive
Office of Radiation Programs Montgomery, AL 36109
Radiation
Radiological Survey of
Kings Bay Submarine
Support Facility
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Radiological Survey
of
Kings Bay Submarine Support Facility
Sam T. Windham
Eastern Environmental Radiation Facility
1890 Federal Drive
Montgomery, AL 36109
October 1987
U.S. Environmental Protection Agency
Office of Radiation Programs
401 M Street SW
Washington, DC 20460
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Table of Contents
List of Illustrations v
Preface vii
Introduction 1
Characteristics of Kings Bay Submarine Support Facility 2
Survey and Analytical Methods 4
Results and Discussion 7
Conclusion 11
References 12
in
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Figures
List of Illustrations
1 General Site Location 3
2 Sampling Locations 5
3 Shoreline Radiation Survey Locations and Results ... 10
Tables
1 Results of Bay Water Analyses 8
2 Results of Drinking Water Analyses 8
3 Results of Vegetation Sample Analysis 8
4 Shoreline Radiation Measurements 9
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Preface
The Office of Radiation Programs identifies and evaluates
environmental public health impacts of both natural and man-made radiation
sources. The Eastern Environmental Radiation Facility (EERF) is a fully
integrated participant with other components of the Office in these
efforts. The Facility provides comprehensive capability for evaluating
radiation sources through planning and conducting environmental studies,
nationwide surveillance, and laboratory analysis. The EERF also provides
special analytical support for Environmental Protection Agency Regional
Offices and other Federal government agencies, as requested, as well as
technical assistance to the radiological health programs of State and
local health departments.
This report presents results of the survey conducted by EERF
personnel to assess levels of environmental radioactivity resulting from
maintenance and operation of nuclear-powered warships at the Kings Bay
Submarine Support Facility, Kingsland, Georgia. The purpose of the survey
was to determine if activities related to nuclear-powered warship resulted
in release of radionuclides which may contribute to significant population
exposure or contamination of the environment.
Readers of our reports are encouraged to bring comments, omissions or
errors to our attention.
Charles R. Porter, Director
Eastern Environmental Radiation Facility
Vll
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Introduction
Since 1963, the Eastern Environmental Radiation Facility (EERF),
U.S. Environmental Protection Agency (USEPA), in cooperation with the
U.S. Naval Sea Systems Command (NAVSEA) has surveyed facilities serving
nuclear-powered warships on the Atlantic and Pacific coasts and the Gulf
of Mexico. These surveys assess whether the operation of nuclear-powered
warships, during construction, maintenance, overhaul, or refueling, have
created elevated levels of radioactivity. The surveys emphasize sampling
those areas and pathways that could expose the public.
In 1984, NAVSEA requested that all active facilities servicing
nuclear-powered warships be resurveyed over the next three years. Kings
Bay Submarine Support Facility (KBSSF), located adjacent to St. Marys,
Georgia and approximately 10 miles east of Kingsland, Georgia, was
surveyed by EERF personnel in August 1985. The KBSSF has not been
previously surveyed by the EERF or its predecessor (the U.S. Public Health
Service) since the area had not been visited by nuclear-powered warships
until approximately 1980 (6086).
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Characteristics of Kings Bay Submarine Support Facility
The KBSSF is located in southeast Georgia adjacent to St. Marys and
approximately 10 miles from Kingsland and about 30 miles north of
Jacksonville, Florida. The facility is on Kings Bay just off Cumberland
Sound which is created by Cumberland Island, a barrier island on Georgia's
Atlantic coast (see site location map, Figure 1). The facility consists
of three primary areas of work; a floating dry dock located to the
southeast near the entrance to Kings Bay; a central pier which presently
is the center of most activity; and a new pier area located to the
northwest into Kings Bay.
Most of the Kings Bay area consists of shallow water and tidal
marshes except for the area of the ship channels which have been deepened
by dredging. Fishing and boating were noted in the local area,
particularly on Cumberland Sound which is part of the intercoastal
waterway.
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Georgia
Florida
Kingsland
Brunswick
Cumberland Is
Kings Bay
Submarine
(KBSSF)
General Site Location
Figure 1
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Survey and Analytical Methods
Navy personnel helped the EERF survey team identify the most probable
sampling locations, those where radioactivity associated with Naval
nuclear propulsion plants, if it were present, would most likely be
detected. Extensive sampling was done near the dry dock; central pier;
and the new pier areas where nuclear warships are or have been serviced.
Sampling sites are shown in Figure 2. Samples of bottom sediment, water,
and aquatic life were taken.
According to past surveys, cobalt-60 is the predominant radioisotope
found in environmental media as a result of Naval nuclear propulsion
plants; therefore, environmental sampling focused on detecting this
radioiostope. Cobalt-60 content in all samples was determined by gamma
analysis. All water samples were also analyzed for tritium since the
nuclide is known to be produced in the coolant of light water nuclear
reactors.
An underwater gamma scintillation probe with a 10 centimeter by 10
centimeter sodium iodide detector was used with a portable multichannel
pulse height analyzer to help locate areas of radioactivity. All probe
measurements were made for 10 minutes. The underwater probe has been
useful in past surveys of other facilities to select areas for dredge
sampling of bottom sediment and to delineate areas of radioactivity.
However, due to the relatively low sensitivity (as compared to laboratory
measurements) of the probe, sediment samples were collected at the
locations of probe measurement for laboratory analysis. Probe
measurements and sampling were duplicated for quality assurance purposes
at approximately 10% of the sites.
A standard Peterson dredge was used to sample approximately the top
10 centimeters of sediment. These sediment samples were collected at
locations 1 through 31 shown in Figure 2. At the laboratory these samples
were dried, ground to a fine powder, placed in a 400 cnr sample counting
container and counted on a Ge(Li) or intrinsic germanium detector for 1000
minutes. The minimum detectable activity for cobalt-60 in this geometry
is approximately 0.01 picocuries per gram (pCi/g).
Sediment core samples are useful in determining the vertical
distribution of radioactivity in harbor bottom sediment. If radioactive
materials were present from past operations which were subsequently
covered with sediment, it might be observed in the core samples. Core
samples were taken with a 3.8 centimeter diameter by 61 centimeter long
plastic tube. A diver pushed the tube into the sediment as far as
possible and capped the ends. Core samples were collected at locations
34, 35, 36, and 37 shown in Figure 2. At the laboratory the cores were
frozen and cut into 2.5 cm sections. The individual sections were
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28
Sampling Locations
Figure 2
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freeze-dried and counted on a Ge(Li) or intrinsic germanium detector to
determine gamma emitting radioisotopes. The minimum detectable activity
for cobalt-60 in the geometry is approximately 0.1 pCi/g.
Water samples were collected at two locations in the harbor (1 and
28) and from two public drinking water supplies (32 and 33). These
samples were analyzed for gamma emitters (especially Co-60) and for
tritium. The minimum detectable activity for tritium in water is
200 pCi/1.
Aquatic life samples were collected at 4 locations during the
survey. Oysters collected at locations 34, 38, and 39 were the only
marine samples available. Unfortunately upon opening the shells at the
EERF, no oysters were inside. A vegetation sample was collected at site
29. At the laboratory the vegetation was dried and counted in a Ge(Li) or
intrinsic germanium detector for 1000 minutes.
A shoreline gamma radiation survey was made using portable
scintillation survey instruments that were periodically calibrated with a
high pressure ionization chamber. All measurements were made 1 meter
above the ground. The surveys were made on accessible shorelines in the
KBSSF area and in publicly accessible areas nearby.
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Results and Discussion
Harbor bottom sediment sampling was the most extensive since past
surveys have shown that if radioactivity had been released it usually
would be detectable in the sediment. Samples were collected at 31
locations. No cobalt-60 or other gamma emitting nuclides from
nuclear-powered warship operations were found in any of the samples.
Only naturally occurring nuclides and trace quantities of cesium-137,
typically fallout from previous worldwide nuclear weapons testing, were
found in the samples.
Core samples collected at 4 locations were analyzed for gamma
emitting radionuclides. None of the sections from any of the cores
contained radionuclides other than naturally occurring and trace amounts
of cesium-137.
Both water samples collected in the bay had tritium levels below the
minimum detectable level of 200 pCi/1. Potassium-40, a naturally
occurring radionuclide, was the only gamma emitting nuclide detected.
Data are shown in Table 1. No detectable radioactivity was found in the
drinking water samples from the water supplies of KBSSF and Kingsland, GA
as shown in Table 2.
As noted previously, oyster samples collected were not suitable for
analysis. A vegetation sample collected at location 29 had no detectable
radioactivity other than naturally occurring nuclides. Data are presented
in Table 3.
Data from the shoreline gamma radiation survey are summarized in
Table 4 and Figure 3. No radiation levels above normal background which
could be attributable to radioactivity associated with nuclear-powered
warships could be detected. Only naturally occurring radiation was found;
however, a shoreline area that was stabilized with stone did have
radiation levels above the general background level. This is because this
stone, which appears to be large pieces of granite, contains higher levels
of naturally occurring radioactivity than the surrounding terrain. This
stabilized shoreline area is not accessible to the general public and is
not a health or environmental concern. A previous survey of the
Kingsland, Georgia area was conducted in 1968, prior to operation of the
KBSSF (Le68). Gamma radiation levels at the time of that survey averaged
9.2 yR/hr. The average radiation levels measured by EPA, except for the
stone-stabilized shoreline, agree with this previously reported level.
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Table 1
Results of Bay Water Analyses
Activity (pCi/L)
Location Radionuclide + 2 sigma error
KBW 1
KBW 28
K-40
K-40
260 + 58%
270 + 22%
Table 2
Results of Drinking Water Analyses
Activity (pCi/L)
Location Radionuclide +_ 2 sigma error
KBW 32 (KBSSF drinking water) All
KBW 33 (Kingsland, GA drinking water) All
N.D. - all radionuclides below detectable limits.
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Table 3
Results of Vegetation Sample Analyses
Activity (pCi/g)a
Location Radionuclide +_ 2 sigma error
KBV 29
K-40
Pb-214
Bi-214
Ra-226
7.5 + 8%
.87 + 8%
.84 + 10%
1.0 +45%
aActivity per gram dry weight.
Table 4
Shoreline Radiation Measurements9'
Location Exposure yR/hr
- Near site 31 shoreline 5
- Between sites 30 and 31 4-5
- Near site 30 shoreline 5-7
- Near site 29 shoreline and toward 30 5-8
- Along pier between sites 43 and 18 8-10
- Shoreline NW of site 18 on unstabilized shore 5-10
- Shoreline stabilized with stone SE of new "T" pier 12-15C
aSurvey was made while walking so the range values represent the
least and greatest values encountered.
^Readings include background and were made at nominal high tide.
cAs noted in the text, the stone contains higher levels of natural
radioactivity than the surrounding terrain.
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12-15
GRANITE^X-
FILL
Legend: 1" =
- readings
Shoreline Gamma Survey Locations and Results
Figure 3
10
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Conclusions
The radiological survey of the Kings Bay Submarine Support Facility
provided the basis for the following conclusions.
1. Only radionuclides of natural origin plus trace quantities of
Cs-137 from previous nuclear weapons testing were found in any
of the samples. No Co-60 or H-3, radionuclides associated with
nuclear-powered warship operation, were found in any of the
samples.
2. The only shoreline gamma radiation levels which were elevated
above the local natural background resulted from stone which had
been brought in to stabilize the shoreline. The stone contains
levels of natural radioactivity slightly greater than the local
terrain.
3. Bay water and drinking water samples contained no detectable
levels of radioactivity other than naturally occurring.
4. Based on this survey, operations related to nuclear-powered
warship activities at Kings Bay have resulted in no detectable
increases in radioactivity that would result in significant
population exposure or contamination of the environment.
11
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References
Go86 Gorring, Ron, personal communication from U.S. Naval Sea
System Command, November, 1986.
Le68 Levin, S.G., Stoms, R.K., Kuerze, E., and Kuskisson, W.,
1968, National Center of Radiological Health, "Summary of
Natural Environmental Gamma Radiation Using a Calibrated
Portable Scintillation Counter", Radio1ogica1 Hea1th Data
and Reports, 9, 11.
12 *U GAPS *L(8B0429)500
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