ML13184A139

an Aerial Radiological Survey of the Seabrook Nuclear Station and Surrounding Area - July 1988

ML13184A139
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Site:	Seabrook
Issue date:	09/30/2013
From:	Guss P EG&G Energy Measurements
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DE-AC08-88NV10617, UC-41 EGG-10617-1013
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n EGc.G THE

~~ENERGYMEASUREMENT.S REMOTE SENSING EGG-1 0617-1013 LABORATORY UC-41 OPERATED FOR THE U.S.

SEPTEMBER 1989 DEPARTMENT OF ENERGY BY EG&G/ EM AN AERIAL RADIOLOGICAL SURVEY OF THE SEABROOK NUCLEAR STATION AND SURROUNDING AREA SEABROOK, NEW HAMPSHIRE DATE OF SURVEY: JULY 1988

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n EGc.G EGG-10617-1013

~~ENERGYMEASUREMENT.S SEPTEMBER 1989 AN AERIAL RADIOLOGICAL SURVEY OF THE SEABROOK NUCLEAR STATION AND SURROUNDING AREA SEABROOK, NEW HAMPSHIRE DATE OF SURVEY: JULY 1988 P. P. Guss Project Scientist REVIEWED BY W. J. Tipton ~ssi mnt Manager Aerial Measurements Operations This Document is UNCLASSIFIED e.x.~~-

ctK. Mitchell Classification Officer This work was performed by EG&G/EM for the United States Department of Energy, Office of Nuclear Safety, and the United States Nuclear Regulatory Commission under Contract Number DE-AC08-88NV1 0617.

ABSTRACT An aerial radiological survey was conducted over the Seabrook Nuclear Station, Seabrook, New Hampshire, during the period 6 July through 14 July 1988. The purpose of the 247-square-kilometer (96-square-mile) survey was to document the terrestrial gamma environment of the station and surrounding area.

An exposure rate contour map at 1 meter above ground level (AGL) was constructed from the gamma data and overlaid on an aerial photograph and map of the area. Exposure rates measured in the area typically ranged from 9 to 12 microroentgens per hour (f..LR/h). In areas where water shielded the earth, lower exposure rates were measured.

Ground-based exposure rate measurements and soil samples were obtained to support the aerial data.

Oblique aerial photographs of the station were also acquired during the survey.

2

CONTENTS Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Sections 1.0 Introduction 5 2.0 Site Description ... . 5 3.0 Natural Background . 5 4.0 Survey Equipment and Methods ..... ... .. . . .. .. ... .. . .... . . . 5 4.1 Aircraft System . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 5 4.2 Data Van . . . . . . . . . . .. . . .. . .. ... . .. . .... .... . . .... . 7 4.3 Survey Method . . . . . . . . . . . . . . . . . . . . . . ... .. .. . . . . . . . . 7 4.4 Aerial Photographs . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . .. . 8 4.5 Ground-Based Measurements . . . . . . . . . . ... .. .. .. ... . .. . . 8 5.0 General Data Reduction . ... . . . . . . . . . . . . . . . . . . . . . . .. ... .. . 8 5.1 Gross Count Rate . . . . . . . . . . . . . . . . . . . . . . . . .. . ... .. .. . 8 5.2 Spectral Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 6.0 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 6.1 Exposure Rate Contour Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 6.2 Spectral Window Contour Map . .. .. ... .. . .... .. 10 6.3 Ground-Based Measurement Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.0 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figures General View of the Seabrook Nuclear Station and Surrounding Area Showing the Station, Survey Boundary, and URS Transponder Locations for the July 1988 Survey . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 6 2 MBB B0-105 Helicopter with Detector Pods . .. .. .. . .... ... . .. . . . 7 3 Mobile Computer Processing Laboratory ..... . . .. ... . . . . . . . . . . . 7 4 Terrestrial Gamma Exposure Rate Contour Map from the July 1988 Survey of the Seabrook Nuclear Station and Ground-Based Measurement Locations . .... .. . .. .... . . . . . . . . ..... .. ... . . . . . . . . . . . 9 5 Typical Gamma Energy Spectrum Obtained within the Survey Boundary Minus a Background Spectrum Taken over Great Bay . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3

Table 1 Comparison Between Ground-Based and Aerial Measurements . . . . . . . . . . . . . . . . . . . . . 12 Appendix A Survey Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4

1.0 INTRODUCTION

3.0 NATURAL BACKGROUND An aerial radiological survey was conducted over Natural background originates from three primary the Seabrook Nuclear Station and surrounding sources. They are: radioactive elements present area from 6 July to 14 July 1988 by EG&G Energy in the earth, airborne radon, and cosmic rays Measurements, Inc. (EG&G/EM) of Las Vegas, entering the earth's atmosphere from space.

Nevada. The purpose of the survey was to map the The natural terrestrial radiation levels depend background terrestrial gamma exposure rates upon the type of soil and bedrock immediately around the station. This was achieved by flying below and surrounding the point of measurement.

survey lines at 152-meter (500-foot) intervals at an In urban areas, the levels are also dependent on the altitude of 91 meters (300 feet) over an area of 24 7 natureofstreetand building materials. The gamma square kilometers (96 square miles). An exposure radiation originates primarily from the uranium rate contour map of the area was derived from the decay chain, the thorium decay chain, and radio-aerial data. In addition, ground-based exposure active potassium.ln general, local concentrations rate measurements and soil samples were of these nuclides produce radiation levels at the obtained to support the aerial measurements. surface of the earth typically ranging from 1 to 15 Oblique aerial photographs of the station were 11R/h (9 to 130 mrem/yr) .2 Some areas with high also taken during the survey. uranium and/or thorium concentrations in the surface minerals may exhibit even higher levels.

The survey was sponsored by the United States Department of Energy (DOE), Office of Nuclear Both the uranium and thorium radioactive decay Safety (ONS), and the United States Nuclear chains contain isotopes of radon. Radon is a Regulatory Commission (NRC). EG&G/EM, a noble gas which can diffuse through the soil as prime contractor of the DOE, has conducted well as disperse through the air. Therefore, the aerial radiological surveys for the DOE, the NRC, level of airborne radiation due to these radon and other U.S. government agencies for more isotopes and their daughter products at any than 25 years. The basic uti Iity of the aerial survey specific location depends on a variety of factors, is that the coverage of the survey area approaches including meteorological conditions, the mineral 100 percent. content of the soil, and soil permeabi Iity. Typically, airborne radiation contributes from 1 to 10 percent of the natural background radiation levels.

2.0 SITE DESCRIPTION Cosmic rays interact with elements of the earth's atmosphere and soil. These interactions produce The survey boundary is depicted in Figure 1. The an additional natural source of gamma radiation.

area is a 247-square-kilometer (96-square-mile) Radiation levels due to cosmic rays vary with rectangle. The 19-kilometer by 13-kilometer (12- altitude from 3.3 11R/h at sea level to 12 11R/h at an mile by 8-mile) survey region extends parallel to altitude of 3 kilometers.3 For Seabrook, New the sea coast 9.5 kilometers north and south of the Hampshire, where the elevation varies from sea Seabrook Station, 8 kilometers west of the station, level to 100 meters, the cosmic ray contribution is and 5 kilometers east of the station. The coast Ii ne about 3.6 11R/h.

forms the eastern boundary. The nuclear station is located in the town of Seabrook, New Hampshire, and is situated on a tidal basin which extends 5 4.0 SURVEY EQUIPMENT AND METHODS kilometers inland from the Atlantic Ocean. The surrounding coastal terrain varies in elevation 4.1 Aircraft System from sea-level to maximum elevations of approxi- A Messerschmitt-Bolkow-Biohm (MBB) B0-105 mately 100 meters. helicopter was used as the aerial platform (Figure 2). The aircraft carried two detector pods, each Presently, only a single Westinghouse PWR-type containing four 10.2-cm X 10.2-cm X 40.6-cm (4-reactor operated by the New Hampshire Yankee in X 4-in X 16-in) log-type thallium-activated Power Company is at the site. The maximum sodium iodide, Nai(T£), gamma detectors.

electrical output of the unit is 1,150 megawatts.

During the survey period, the station had not yet Gamma signals originating in the Nai(T£)

been licensed to operate. 1 detectors were routed to the Radiation and 5

FIGURE 1. GENERAL VIEW OF THE SEABROOK NUCLEAR STATION AND SURROUNDING AREA SHOWING THE STATION, SURVEY BOUNDARY, AND URS TRANSPONDER LOCATIONS FOR THE JULY 1988 SURVEY 6

FIGURE 2. MBB B0-105 HELICOPTER WITH DETECTOR PODS Environmental Data Acquisition and Recorder (REDAR IV) system for analog-to-digital conver-sion and storage on magnetic tape . Pressure, temperature, and radar altitude transducer data FIGURE 3. MOBILE COMPUTER PROCESSING were also acquired and stored by the REDAR. LABORATORY Real-time gamma energy spectra, total gamma count rates, and other data were output to a small CRT screen for the system operator. Hampshire , and the other at Pease Air Force The aircraft pilot was guided over the programmed Base adjacent to Portsmouth , New Hamp-flight lines by an indicator that derived its signal shire. These two locations and the Seabrook from the triangulation of the ultrahigh-frequency Nuclear Station formed an approximate equi-(UHF) transponders, located on the ground, and a lateral triangle that optimized the positioning master unit, located in the aircraft. The position and steering of the aircraft during the survey.

data were also recorded by the REDAR. 2. A perimeter flight of roads in the survey area was then made. The transponder data from the perimeter flight were used to scale dis-tances to a road map of the survey area. In 4.2 Data Van this way, each subsequent gamma datum A minicomputer-based system (Figure 3) housed could be plotted accurately (within about 9 in a van was used during the survey to evaluate meters) on the map .

the aerial data obtained from each flight. The 3. The locations of a test line and a water line system contains hardware and software that were designated during the perimeter flight.

operate on the survey data stored on the magnetic Ocean Bay provided an expanse of water from tape . The system operator can plot both gamma which changing background atmospheric energy spectra from any portion of the gamma radon could be measured. The 2-kilometer survey and count rate isopleths scaled to a map or test line was directed from east to west. The photograph. In this manner, gamma emitters, test line followed utility power lines which their intensity, and their location can be identified. were situated 3 kilometers south of Great Bay. This series of test and water lines flown before and after every individual flight served to monitor possible changes in system sensi-4.3 Survey Method tivity and also functioned as survey data A standardized procedure for aerial gamma quality control.

surveys was followed during the survey of the 4. Following the perimeter, test line, and water Seabrook Nuclear Station. Steps in the procedure line flights, routine flights began . All survey are as follows : lines were flown at an altitude of 91 meters.

1. Two UHF transponders were placed outside Each flight-preceded by a preflight in which the survey area: one in Epping, New the system was calibrated and the data tape 7

was analyzed for proper system operation- system's Nal (T£) detectors. The first is the gross consisted of: count (GC) technique which is used to determine

a. A pass over the water line at survey exposure rates . The second is the spectral window altitude technique which is used to measure concen-

b. A pass over the test line at survey altitude trations of specific nuclides . These and other

c. Passes in an east/west direction following methods are described in detail in a separate preprogrammed lines over the survey area publication .6 d . A pass over the test line at survey altitude

e. A pass over the water line at survey altitude 5.1 Gross Count Rate Following each survey flight, the data were The gross count rate is defined as the integral examined by computer to verify system integrity count for 1 second in the energy spectrum be-and validate data quality. tween 40 keV and 3,044 keV.

5. The aerial data were extrapolated to 1 meter above the ground, and a contour map was drawn of the exposure rates. A contour map 3,044 keV was also drawn from an algorithm designed to show possible man-made gamma activity. GC Energy Spectrum ( 1)

E = 40 keV 4.4 Aerial Photographs The integral includes all the natural gammas from Oblique documentary aerial photographs were potassium-40 (K-40), uranium-238 (U-238),

taken of the Seabrook Nuclear Station during the thorium-232 (Th-232), and their decay products survey period. The photographs are stored at (the major terrestrial natural gamma emitters) .

EG&G/EM and are available to qualified users. A Other natural contributors to this integral are high-altitude vertical photograph of the station cosmic rays, aircraft background , and airborne was taken on 7 June 1988. This photograph radon daughters.

serves as part of the map underlay in Figure 4.

The altitudinal response of the aerial system for terrestrial gammas was measured over the test line . The survey count rates were then extrapo-4.5 Ground-Based Measurements lated to 1 meter above the ground from the Exposure rates were measured , and soil samples altitude response curve . The conversion from were obtained at seven locations (Figure 4) during count rate to exposure rate was obtained from the the second week of the survey. These measure- documented test line in Calvert County, Maryland .

ments were made to support the integrity of the The conversion equation is :

aerial results. A Reuter-Stokes pressurized ionization chamber was used for each exposure GC(A) - B measurement. Soil samples, to a depth of 15.0 em, ER(l m) (2) were also obtained at the center and at four points 1,450 of the compass on the circumference of a 120-meter diameter circular area centered at the where position where the measurement was performed ER(l m) Exposure rate extrapolated to using the ionization chamber. The soil samples 1 m above ground level (J1R/h) were dried, and their gamma activities were GC(A) Gross count rate at alt itude A measured on a germanium-based detector system (cps) 45 at the EG&G/EM Santa Barbara laboratory.

• A = Altitude (feet)

B = Cosmic, aircraft, and airborne radon background (cps) 5.0 GENERAL DATA REDUCTION a = Absorption coefficient.

Two primary methods are used to evaluate the Determined from altitude spiral gamma flux measurements made with the aerial data to be 0.002/ft 8

CONVERSION SCALE I

0 2 GAMMA LETTER EXPOSURE RATE*

LABEL AT 1m ( J1R/ h)

< 6 N A B 6- 9 c 9-12 D 12-15

• Exposure rates are inferred from gamma count rates obtained at the survey alti-tude of 90m and extrapolated to the 1m level. Includes 3.6 J1R / h contribution from cosmic rays.

FIGURE 4. TERRESTRIAL GAMMA EXPOSURE RATE CONTOUR MAP FROM THE JULY 1988 SURVEY OF THE SEABROOK NUCLEAR STAT/ON AND GROUND-BASED MEASUREMENT LOCATIONS 9

Equation 2 was used to compute the exposure where rate from the terrestrial gross count rate. For the S = net count rate (signal) from anomalous Seabrook survey, flown at 91 meters, Equation 2 gamma rays (cps) becomes:

The signal, S, will vary around zero and become GC-B significantly positive in the presence of anomalous ER(l m) (3) gamma rays whose primary (unscattered) energy 790 lies between a and b . The variance of S can be computed from the results of Equation 5 or from The gross count has been used for many years in the energy window count rates.

the aerial system as a measure of exposure rate.

Its simplicity yields a rapid assessment of the Equation 5 was applied to the Seabrook survey gamma environment. data in the search for possible man-made emitters.

In the search, a was 40 keV, b=c was 1,400 keV, Anomalous or nonnatural gamma sources can and d was 3,044 keV. These limits placed most of often be found from increases in gross count the long-lived, man-made gamma emitters within rates. However, subtle anomalies are difficult to the signal window, S.

find using the gross count rate in areas where its magnitude is variable due to geologic or ground cover changes, for example. Differential energy data reduction methods, as discussed in the next 6.0 RESULTS section, are used to increase the aerial system's sensitivity to anomalous gamma emitters.

6.1 Exposure Rate Contour Map The exposure rate contour map, Figure 4, contains the principal results from the survey of the 5.2 Spectral Windows Seabrook Nuclear Station. This map shows the gamma exposure rate at 1 meter above ground The aerial system produces, each second, a level over the 247-square-kilometer (96-square-gamma energy spectrum from which the GC is mile) area surrounding the Seabrook station. The computed. Generally, the ratio of natural com- cosmic exposure rate7 (3.6 f..LR/ h) was included in ponents in any two integral sections (windows) of producing the contour levels, but the highly the energy spectrum will remain nearly constant variable airborne radon component (0 to 0.2 in any given area: f..LR/h) was not.

E~ (ES) IE* (ES) = Constant = K (4)

The contour map consists of approximately 46,000 data points, each representing 0.6 hectares (1.4 acres). Each data point includes a 1,000-channel gamma energy spectrum, a pressure and tempera-ture measurement, and measured spatial coordi-nates (altitude and two ranges from the tran-where sponders on the ground).

ES = Energy spectrum The exposure rates are, in general, from 9 f..LR/h to E = Energy 12 {.lR/h over the land areas. The wetlands were d>c2':b>a found to have lower exposure rates.

In practice, the value of K(Equation 4) is obtained Figure 5 shows a typical energy spectrum taken from the natural terrestrial background of the within the survey boundary. In the survey region, survey area and the test line. Then Equation 4, in only normal background sources of radiation another form, is evaluated from the spectra were observed, as indicated in the figure.

obtained over the survey area:

b d 6.2 Spectral Window Contour Map S= ~ (ES)- K * ~ (ES) (5)

The spectral window technique was employed to E=a E= c produce a contour plot of S (Equation 5) over the 10

1.0 t ----+-___,1---+--l-- 1---+------+- +---+---+-+---t survey. The soil samples were dried and counted on a calibrated gamma spectrometer in the labora-

+.8 tory. The in-situ exposures were computed from

_jw w_j the primary isotopic concentrations in the soil z <t: samplesa and included the effect of soil moisture.e z &S

<{ _j +.6 214 Bi The exposure values are compared with the ion I_l 1240 keV O :::J a:LL 40 K chamber measurements in Table 1. These expo-W (f)

CL 1- +.4 1460 keV sure values represent the terrestrial plus the (J)Z i-:::J zo I cosmic components. A small airborne radon

JO component (0 .2 J.1R/ h or less) is also included in 20BTJ 0

oo v +.2 2615 keV the ion chamber measurement. Exposure values inferred from an isotopic analysis of the aerial I data are also presented in Table 1.

+5 1.5 2.0 2.5 3.0 Exposure rate measurements on the ground agree

+.0 1.0 ENERGY (MeV )

well, within system uncertainties, with the mea-sured aerial exposure rates. The isotopic con-FIGURE 5. TYPICAL GAMMA ENERGY SPECTRUM centrations for the soil samples also agree within OBTAINED WITHIN THE SURVEY BOUNDARY MINUS A BACKGROUND 30% of the aerial data.

SPECTRUM TAKEN OVER GREAT BAY 7.0

SUMMARY

survey area in a search for man-made emitters.

However, the contour map shows no evidence of A 247-square-kilometer (96-square-mile) area, any man-made emitters and, consequently, is not centered on the the Seabrook Nuclear Station shown here. near Seabrook, New Hampshire, was radio-logically surveyed at an altitude of 91 meters utilizing the AMS. No significant above -

6.3 Ground-Based Measurement Results background levels were observed . Average expo-sure rates dete rmined for 1 meter above ground lon chamber measurements and soil samples level were found to vary from 9 to 12 micro-were collected at seven sites within the survey roentgens per hou r. No man-made radioisotopes boundaries during the final week of the aerial were detected within the survey area.

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Table 1. Comparison Between Ground-Based and Aerial Measurements Exposure Rate d Dry Soil Isotopic Compositionc (MR/h at 1 m AGL)

Moistureb U-238 Th-232 Cs-137* K-40 Soil Ion Site* Type  % (ppm) (ppm) (pCi/g) (pCi/g) Data Chamber 1 Ground 4.3 +/- 1.2 2.0 +/- 0.4 6.9 +/- 1.2 0.25 +/- 0.04 15.6 +/- 0.6 9.6 +/- 0.8 9.1 +/- 0.5 Aerial 2.1 7.8 13.6 10.3 +/- 0.5 2 Ground 13 +/- 5 2.7 +/- 0.2 8.6 +/- 0.8 0.49 +/- 0.22 14.6 +/- 0.7 9.8 +/- 0.9 9.2 +/- 0.5 Aerial 3.6 8.2 11.4 10.6 +/- 0.5 3 Ground 21 +/- 5 2.9 +/- 0.6 10 +/- 2 0.40+/-0.16 14.5 +/- 0.4 10.0 +/- 1.0 9 +/- 10 Aerial 2.1 6.8 10.9 9.2 +/- 0.5 4 Ground 12 +/- 3 1.9+/-0.1 6.6 +/- 0.3 0.54 +/- 0.11 13.7 +/- 0.3 8.7 +/- 0.4 8.5 +/- 0.5 Aerial 1.6 4.5 7.8 9.0 +/- 0.5 5 Ground 60 +/- 2 3.1 +/- 0.1 9.4 +/- 0.4 0.12 +/- 0.01 15.4+/-1 .0 8.4 +/- 0.4 {f)

Aerial 1.8 5.4 8.1 8.7 +/- 0.5 6 Ground 8+/-1 2.0 +/- 0.1 7.5 +/- 0.2 0.16+/-0.01 16.7 +/- 1.0 9.7 +/- 0.4 (r)

Aerial 2.3 5.8 13.3 9.3 +/- 0.5 7g Ground 2+/- 1 1.0 +/- 0.1 4.1 +/- 0.2 0.02 +/- 0.01 17.2+/-1 .0 8.5 +/- 0.4 (r)

Aerial 1.1 2.6 6.0 6.5 +/- 0.5 a The site locations are shown in Figure 4.

b Aerially measured isotope concentrations were increased to account for using the soil sample moisture measurements .

cThe errors in the aerial isotopic measurement are not we ll determined to date.

d Exposure rate includes the cosmic fraction of 3.6 J.1R/ h and the effect of soil moisture. The exposure rates from the isotopic concentrations were compiled using Beck's conversions.a

• No attempt was made to extract the small Cs-137 count rates from the aerial data.

rNo ion chamber data taken g Because Site 7 was an isthmus more narrow than the aerial detector's f ield of view, the aerial measurements will underestimate the actual exposure rate.

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APPENDIX A SURVEY PARAMETERS Survey Site: Seabrook Nuclear Station Seabrook , New Hampshire Survey Coverage: 247 sq km (96 sq mi)

Survey Date: 6 July 1988 to 14 July 1988 Survey Altitude: 91 m (300ft)

Aircraft Speed : 36 m/s (70 knots)

Line Spacing: 152 m (500 ft)

Line Length: 13 km (8 mi)

Line Direction: East-West Number of Lines: 124 Detector Array: Eight 10.2-cm X 10.2-cm X 40.6-cm (4-in X 4-in X 16-in) Nai(T£) detectors Acquisition System: REDAR IV Aircraft: MBB B0-105 Helicopter Survey Crew: P. Guss, J. Butler, L. Komich, R. Rea, C.

Roberts, W. Verheyden, M. Haley, R. Mohr Data Processing:

1. Gross Count Window: 40 to 3,044 MeV

2. Conversion Factor: 790 cps per J1R/h

3. Cosmic Ray Contribution: 3.6 J1R/h 13

REFERENCES

1. Kwasnik, J. 1988. Private Communication. New Hampshire Yankee Power Company, Seabrook Nuclear Station

2. Lindeken, C.L., eta/. 1972. "Geographical Variations in Environmental Radiation Background in the United States." Proceedings of the Second International Symposium on the Natural Radiation Environment. 7-11 August 1972, Houston, Texas: pp. 317-332. Springfield, VA: National Technical Information Service, U.S. Department of Commerce.

3. Klement, A.W., et at. August 1972. Estimate of Ionizing Radiation Doses in the United States 1960-2000. U.S. EPA Report No. ORD/CD72-1. Washington , D.C.: Environmental Protection Agency.

4. Quam, W. and Engberg, K. October 1978. Low Background Ge(Li) Detector with Anticoincidence Nal Annulus. Report No. EGG-1183-2326. Santa Barbara, CA: EG&G/ EM .

5. Low Background Ge(Li) Detector Gamma-Ray Spectroscopy System with Sample Changer. Report No. EGG-1183-2383 . Santa Barbara, CA: EG&G/ EM

6. Boyns, P.K. July 1976. The Aerial Radiological Measuring System (ARMS): Systems, Procedures and Sensitivity. Report No. EGG-1183-1691. Las Vegas, NV: EG&G/ EM .

7. Environmental Radiation Measurements. December 1976. NCRP Report No. 50, p. 30. Washington, D.C .: National Council on Radiation and Measurements.

8. Beck, H.L., eta/. September 1972. In Situ Ge(Li) and (Ti) Gamma-Ray Spectrometry. Report No.

HASL 258, TID-4500. Health and Safety Laboratory : U.S. Atomic Energy Commission .

9. Caroll, T.R . November 1981 . " A irborne Soi l Moisture Measurement Using Natural Terrestrial Gamma Radiation." Soil Science . Vol. 132, No. 5.

14

DISTRIBUTION NRC/HQ LBL E. D. Weinstein (1) H. A. Wollenberg ( 1)

EG&G/EM NRC/REGION I (7) P. K. Boyns LVAO ( 1)

R. J. Summers Z. G. Burson LVAO ( 1)

H.W. Clark LVAO ( 1)

J. F. Doyle LVAO ( 1)

DOE/ONS L. A. Franks SBO ( 1)

P. P. Guss WAMD ( 1)

W. F. Wolff (5) T. J. Hendricks LVAO ( 1)

H.W. Jackson SBO ( 1)

D. A. Jessup SBO (2)

K. R. Lamison WAMD (5)

DOE/OMA ( 1)

H. A. Lamonds LVAO E. K. Matson ( 1) J. A. Michael LVAO ( 1)

C.K. Mitchell LVAO ( 1)

R. A. Mohr SBO ( 1)

L. G. Sasso LVAO (1 )

DOE/OSTI W.J . Tipton LVAO ( 1)

P. H. Zavattaro LVAO ( 1)

S. F. Lanier (2)

LIBRARIES DOE/NV AMO (1 0)

J. D. Barrett ( 1) Archives (1 )

G.M . Plummer ( 1) WAMD ( 1)

SEABROOK NUCLEAR STATION SEABROOK, NEW HAMPSHIRE EGG-10617-1013 DATE OF SURVEY: JULY 1988 DATE OF REPORT: SEPTEMBER 1989