ML20036C163

Forwards Final Rept Confirmatory Survey of Facilities in Bldg 2,Group 4 & Bldg 9,Stage 2 Rooms,Ga, San Diego,Ca

ML20036C163
Person / Time
Site:	07000734
Issue date:	02/05/1990
From:	Cotten P OAK RIDGE ASSOCIATED UNIVERSITIES
To:	Hooker C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
NUDOCS 9306140340
Download: ML20036C163 (1)

Text

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F d 0, Energy /

'-Q[ ' Oak Ridge Associated ' Post Office Box 117 Enwonment.

Universities. Oak Ricge, Tennessee 37831-0117 Systems Division -

February 5, 1990 Mr. Charles Hooker Region V Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596 Subj ect:

FINAL REPORT, CONFIRMATORY SURVEY OF FACILITIES IN BUILDING 2, GROUP 4 AND BUILDING 9, STAGE 2 ROOMS, CENERAL ATOMICS

[

Dear Mr. Hooker:

Enclosed are five (5) copies of the final report on the Confirmatory Survey of Facilities in Buildings 2, Group 4 Laboratories and Building 9. Stage 2 Rooms, _

General Atomics, San Diego, California.

Please provide any comments your office may have at your earliest convenience.

I may be reached at FTS 626-3355 or contact Jim Berger at FTS 626-3305, i

Sincerely,

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Phy lis R.'Cotten Staff Health Physicist Environmental Survey and Site Assessment Program PRC:jls Enclosures cc: 'CIERdugTnisp'lifMRC/6H33 G. LaRoche, NRC/6H3 D. McCaughey, hTC/6H3 D. Tiktinsky, NRC/6A4 V. Tharpe, NRC/6A4 B. Pate, NRC Region 5 i

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Prcpared by CONFIRMATORY SURVEY Oak Ridge Associated Univ:rsities OF.

Pm;aru f;ar BUILDING 2, GROUP 4 LABORATORIES r

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- Commission's Region V Office BUILDING 9, STAGE 2 ROOMS Sponsored dy GENERAL ATOMICS r

Division of juc"ij^!^4d "*di SAN DIEGO, CALIFORNIA dS P. R. COTTEN t

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Environmental Survey and Site Assessment Program Energy / Environment Systems Division FINAL REPORT; i

JANUARY 1990 L

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NOTICES The opinions expressed herein do not necessarily reflect the opinions of the sponsoring institutions of Oak Ridge Associated Universities.

This report was prepared as an scoount of work sponsored by the Unhed States Government. Neither the United States l

Government nor the U.S. Department of Energy, nor any of their employees, makes any warranty, express or implied, or assumes 3;

cny legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific

. commercial product, proces s, or service by trade name, mark, manufacturer, or otherwise, does not necessarily constitute orimply he endorsement or recommendation, or favoring by the U.S. Government or any agency thereof.The views and opinions of authors cxpressed herein do not necessarily state or reflect those of the U.S. Government or any agency thereof.

I CONFIRMATORY SURVEY 0F I

BUILDING 2, GROUP 4 IABORATORIES AND BUILDING 9. STAGE 2 ROOMS GENERAL ATOMICS SAN DIEGO, CALIFORNIA I

Prepared by P. R. Cotten E.

Environmental Survey & Site Assessment Program Energy / Environment Systems Division Oak Rid e Associated Universities I

S Oak Ridge, TN 37831-0117 Project Staff t

I J. D. Berger C. H. Searcy D. A. Gibson T. J. Sowell-M. J. Laudeman C. F. Weaver E. A. Powell i

Prepared for Division of Industrial and Medical Nuclear Safety U.S. Nuclear Regulatory Commission Region V Office I

FINAL REPORT JANUARY 1990 1

This report is based on work performed under Interagency Agreement (NRC Fin.

No.

A-9076) between the U.S.

Nuclear Regulatory Commission and the U.S Department of

' Energy.

Oak Ridge Associated Universities performs I

complementary work under contract number DE-AC05-760R00033 with.the U.S. Department of Energy.

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I TABLE OF CONTENTS Page 11 List of Figures.

iv List of Tables.

1 Introduction and Site History.

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Site Description.

3 Procedures.

Findings and Results.

6 8

Comparison of Survey Results with Guidelines.

9 Summary...........................

34 References.............

Appendices:

Appendix A: Major Sampling and Analytical Equipment Appendix B: Measurement and Analytical Procedures Appendix C: Guidelines for Decontamination of Facilities I

and Equipment Prior to Release for Unrestricted Use or Termination of Licenses for By-product, Source, or Special Nuclear Material I

Appendix D:

State of California Department of Health Services criteria for Release of Facilities and Equipment to Unrestricted Use Appendix E: Letter from B.R. Tamplin and C. Wong (State of California Department of Health Services) to K. Wong I

(State of California Deparment of Industrial Relations Division of Occupational Safety and Health Radiation Health Unit)

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LIST OF FIGURES Page FIGURE 1:

Map of the San Diego Area, Indicating the Location of General Atomics Facilities.............

10 FIGURE 2:

General Atomics Plant Layout.

11 FIGURE 3:

Layout of Building 2 (L Building Complex) 12 FIGURE 4:

First Floor of Building 9 Indicating the Former I'

Location of the TRIGA Fuel Fabrication " Hot Suite" Area.

13 FIGURE 5:

Section A of Building 2, Indicating Rooms Included in 14 Group 4 Decommissioning.

FIGURE 6:

Section C of Building 2, Indicating Rooms Included in 15 Group 4 Decommissioning.

FIGURE 7:

Decontamination Stages for the " Hot Suite" Area 16 Building 9.

FIGURE 8:

Layout of Room 317, Indicating Locations of 17 Surface Measurements FIGURE 9:

Layout of Room 317 Mezzanine, Indicating Locations of Surface Measurements 18 FIGURE 10:

Layout of Room 355/357, Indicating Locations of Surface Measurements.

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FIGURE 11: Layout of Room 359/361, Indicating Locations of 20 Surface Measurements.

I FIGURE 12:

Layout of Room 359/361 Mezzanine, Indicating 21 Locations of Surface Measurements FIGURE 13:

Layout of Room 554/556, Indicating Locations of I

Surface Measurements.

22 FIGURE 14: Layout of Room 558, Indicating Locations of 23 Surface Measurements.

FIGURE 15:

Layout of Room 560. Indicating Locations of 24 Surface Measurements.

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LIST OF FIGURES (Continued)

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I Page FIGURE 16:

Layout of Room 562/564, Indicating Locations of Surface Measurements.

25 FIGURE 17: Layout of Room 40, Indicating locations of Surface Measurements.

26 FIGURE 18:

Layout of Room 41, Indicating Locations of Surface I

Measurements.

27 FIGURE 19: Locations of Background Measurements from the Vicinity of General Atomics.

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3 LIST OF TABLES Page l

TABLE 1:

Background Radiation Levels.

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TABLE 2:

Summary of Surface Activity Measurements 30 BuildinB 2, L Building Complex.

'. W' TABLE 3:

Radionuclide Concentrations in Residue Samples 32 TABLE 4:

Summary of Surface Activity Measurements Building 9, E Building Complex.

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CONFIRMATORY SURVEY 0F I

BUILDING 2, GROUP 4 LABORATORIES AND BUILDING 9, STAGE 2 ROOMS I

GENERAL ATOMICS SAN DIEGO, CALIFORNIA INTRODUCTION AND SITE HISTORY In mid 1984, General Atomics of San Diego, California, initiated decommissioning activities for the purpose of releasing portions of their facilities from Nuclear Regulatory Commission (NRC) licensing restrictions.

I Decommissioning activities are initiated as land and laboratory facilities are no longer needed for research and development by General Atomics (GA).

Decommissioning at the GA facility is being conducted in several phases.

Phase I activities included the Solar Evaporation Pond, the areas immediately surrounding the former Waste Processing Facility, the area adjacent to the Incinerator Pad, the hillside and canyon below the waste processing facilities, and the undeveloped land surrounding the waste processing facilities; Phase II was the former Waste Processing Facility and the Incinerator Pad; Phase III consisted of approximately 87 hectares of undeveloped land, surrounding the I

main GA plant facilities, and the shipping and receiving area of Building 5; and Phase IV included three canyons behind the Hot Cell and TRIGA facilities, a

former sewage treatment plant known as " Callan Ponds," and 12 laboratories in Building 2 of the L Building Complex.

Phase I, II, III, and IV areas were previously remediated and confirmatory surveys performed by Oak Ridge Associated Universities (ORAU).

Surveys results of Phase I, II, III, and IV are presented in separate reports.(1-4)

Building 2 (E Building Complex) laboratories and offices, included in Phase IV decommissioning were designated as " Group 1" and " Group 2" facilities.

In early 1989, CA decontaminated " Group

.g.

B 3"

facilities which consisted of 19 laboratories, 12 of which have mezzanine areas, and 10 separate mezzanine areas in Building 2, and the " Stage la area in Building 9,

consisting of 9 rooms in the former TRIGA fuel fabrication " Hot Suite" facility.

A total of 1172 m2 were decontaminated and a confirmatory survey was conducted by ORAU; survey results are available in a separate report.5

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GA has completed decontamination of " Group 4" laboratories in Building 2.

" Group 4"

occupies approximately 323 m2 of floor space and consists of 11 laboratories and 3 mezzanines. " Stage 2" decontamination of the former TRIGA

" Hot Suite" in Building 9 includes, Rooms 40 and 41 and occupies a total area 2

m. The primary radionuclides used in Building 2 facilf t-f e= were Co-60, of 52 H-3,

thorium, uranium (natural, depleted, and enriched), Cs-137, and other I

fission products.

In Building 9, uranium with U-235 enrichments, varying from 3 to 10%, was used.

At the request of the NRC, Region V Office, the Environmental Survey and Site Assessment Program of Oak Ridge Associated Universities conducted a confirmatory survey of " Group 4" rooms in Building 2 and " Stage 2" rooms in Building 9 for the purpose of determining if these facilities meet the NRC guidelines for release to unrestricted use.

The survey was performed October 9-12, 1989, in accordance with a survey plan submitted to the Region V I

Office of the NRC.

Procedures and results of this survey are presented in this report.

SITE DESCRIPTION I

The GA facilities are located near the intersection of Interstate 5 and Genesee Road, approximately 20 km north of San Diego, CA (Figures 1 and 2).

Figures 3 and 4 illustrate the floor plans for Buildings 2 and 9.

I Building 2, a two-story, semicircle building, located in the center of the GA complex, consists of office and laboratory space divided into three sections (A,B, and C).

Three laboratories have mezzanine areas which were often used for additional office or laboratory space.

Locations of the " Group 4" laboratories and mezzanines within the Building 2 Complex are illustrated in Figures 5 and 6.

I Building 9,

located ta the west of Building 2, is a large two-story 2

structure with total floor area of 5541 m. GA utilized an area approximately I

375 m2 in the northwest portion of Building 9 to perform fuel fabrication. The TRICA Fuel Fabrication " Hot Suite" operated in this location until operat. ions 2

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were relocated in the late 1970s.

Several areas of the building, including areas in the former " Hot Suite", are currently leased to different companies; GA maintains the facilities telecommunications center in former " Hot Suite" rooms.

" Stage 2" decontamination consist of Rooms 40 and 41 (formerly Rooms 40, 41, 42, 43 and 47), occupying an area approximately 55 m2 (Figure 7).

I PROCEDURES Objectives The obj ectives of the survey were to confirm that the surveys, sampling,

analyses, and supporting documentation provide an accurate and complete description of the radiological condition of the " Group 4" and " Stage 2" areas in Buildings 2 and 9 and, thereby, confirm that decontamination efforts were effective in meeting the NRC guidelines, relative to release of the facilities I

to unrestricted use.

Document Review As part of ORAU's confirmatory activities, the survey reports prepared by GA for " Group 4"

and " Stage 2" decontamination were reviewed by ORAU.(6-7)

Data and survey results presented in these reports were compared to the established release guidelines.

I Facility Survey The following " Group 4" laboratories areas were surveyed in Section A of Building 2: Rooms 554/556, 558, 560, and 562/564; and in Section B, Rooms 317, 355/357, 359/361, the mezzanines of 317 and 359/361.

In the " Hot Suite" of Building 9,

Rooms 40 and 41 were surveyed.

Figures 8 to 1B illustrate the floor plan for each room surveyed.

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Gridding x 2 m reference grid system was established on the An alphanumeric 2 m floor and lower walls (up to 2 m) for each room and mezzanine surveyed.

Measurements made on upper walls, ceilings, or equipment were referenced to the grid or prominent building features.

I Surface Scans Surface scans were performed on the floor and lower walls for evidence of residual activity.

Gamraa scans were performed using a NaI(Tl) gamma scintillation detector and beta-gamma scans were performed using a thin window gas proportional detector was used to scan the GM detector.

A large area floors for alpha and beta-gamma activity. Each detector was connected to a countrate meter with audible signal outputs.

Scans of upper wall, ceilings,

'I and overhead areas such as ledges, beams, piping, fixtures, counter tops, equipment, and ducts were performed using portable ZnS alpha scintillation and GM detectors.

Areas of elevated radiation levels were identified for further investigation.

I Exposure Rate Measurement I

Gamma exposure rates were determined in Buildings 2 and 9, based on gamma lI scan data and cross-calibration with a pressurized ionization chamber.

l Measurement of Surface Activity t

Surface measurements on the floor and lower walls were performed in L

randomly selected grid blocks in Building 2 and Building 9.

Measurements for total alpha and beta-gamma activity levels were systematically performed at the center and four points, midway between the center and block corners.

Smears for removable activity were performed at the locations in each grid block where the highest direct reading was obtained.

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Single point measurements for total and removable alpha and beta-gamma activity were performed on upper walls, overhead surfaces where dust might accumulate (i.e.

ledges, ceilings, beams, pipes, and ducts), drains, counter tops and on miscellaneous equipment.

Surface measurement locations are illustrated in Figures 8 through 18.

Miscellaneous Samples Two residue samples were collected from drainlines in Rooms 317 and 355/357 of Building 2 (Figures 8 and 10). A large aren swipe was used to collect residue from a vent pipe located in Building 9 Room 40, at grid location A, 7.5 (Figure 17).

I Background Measurements Background exposure rate measurements were performed to determine area background levels for comparison purposes.

Locations of the background measurements are shown on Figure 19.

Sample Analyses and Interpretation of Results Samples and direct measurement data were returned to ORAU's laboratory I

facility in Oak Ridge, Tennessee, for analysis and interpretation.

Residue samples were analyzed by gamma spectrometry and the spectra reviewed for the maj or radionuclides of interest, Co-60, Cs-137, U-235, U-238, and Th-232.

Spectra was also reviewed for the presence of other identifiable photopeaks.

Smears were analyzed for gross alpha and beta and H-3.

Additional information concerning major instrumentation, sampling equipment, and analytical procedures is provided in Appendices A and B.

Survey and analysis results are compared to the NRC guidelines established for decommissioning portions of the General Atomics facility (Appendix C).

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FINDINGS AND RESULTS I

Document Review I

A review of the final report of documentation by GA adequately summarizes the radiological status of the two facilities.

Procedures and instrumentation I

used by GA are consistent with current industry accepted practices.

GA has demonstrated that decontamination efforts were successful in meeting the established guidelines.

Background Levels Background exposure rates from the vicinity of the GA facility are presented in Table 1.

Exposures rates ranged from 7 pR/h to 13 pR/h, at 1 m i

from the surface.

These levels are typical of exposure rates normally occurring in the environment.

Facility Survey Exposure rates ranged from 11 pR/h to 18 pR/h in Building 2 and 9 pR/h to 11 pR/h in Building 9.

These levels are below the 10 pR/h above background h7C guideline for external gamma radiation.

Building 2 I

Surface scans of the facilities in Building 2 did not identify any residual activity exceeding the established guidelines.

Five point measurements for total and removable activity were performed in 58 gridblocks on the floor and lower walls.

The results have been summarized in Table 2.

2 and The highest average activity in a gridblock for alpha was 150 dpm/100 cm 2

for

beta, 1400 dpm/100 cm.

Total activity measurements range from I

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<25 dpm/100cm to 980 dpm/100 cm for alpha activity and from <410 dpm/100 cm 2

to 1800 dpm/100 cm for beta-gamma activity.

For the most part, the values indicate activity levels were below the detection sensitivities of the I

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procedure. Removable activity ranged from <3 dpm/100 dpm/100 cm to 21 dpm/100 2

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cm for alpha and ranged from <6 dpm/100 cm to 18 dpm/100 cm for beta-gamma.

A total of 54 single-point direct measurements were collected from various surfaces in Building 2; the results have been summarized in Table 2.

Total 2

2 alpha activity ranged from <25 dpm/100 cm to 980 dpm/100 cm and total 2

2 beta-gamma activity ranged from <410 dpm/100 cm to 5000 dpm/100 cm,

2 Removable alpha and beta-gamma activity levels ranged from <3 dpm/100 cm to 2

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7 dpm/100 cm and <6 dpm/100 cm to 9 dpm/100 cm, respectively.

A total of 115 smears collected from " Group 4" rooms were analyzed for 2

H-3.

The maximum activity determined was < 70 dpm/100 cm,

I Radionuclide concentrations in residue samples have been summarized in Table 3.

The residue collected from Room 355/357 contained 122 pCi/g of U-238.

I The licensee was informed of the findings by telephone and responded by removing all remaining residues from all drains in 355/357 and in 317. The State of California Department of Health Services, Radiological Health Branch, performed a follow-up survey of the drains.

Several smears and a sewage effluent sample were collected.

No residual activity was detected (Appendix E).

I Building 9 Surface scans in Rooms 40 and 41 of Building 9, did not identify any significantly elevated activity. Only the west wall of Room 40 was included in the scan.

It was the only permanent wall of the two rooms.

Five gridblocks on the floor and lower wall were randomly selected for surface activity measurements.

The results have been tabulated in Table 4.

The highest 2

gridblock average for alpha activity was 430 dpm/100 cm and for beta-gamma 2

activity was 990 dpm/100 cm.

No removable activity was detected on any smears.

Three single-point locations in Rooms 40 and 41 were selected for direct 2

2 measurements.

Total activity ranged from <25 dpm/100 cm to 1200 dpm/100 cm 7

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'for alpha and ranged from <410 dpm/100 cm to 2300 dpm/100 cm for beta-gamma.

Removable activity was negligible.

A thin window GM probe was used to scan the large area swipe containing residue from the vent pipe in Room 40; no elevated activity was detected.

COMPARISON OF SURVEY RESULTS WITH GUIDELINES Guidelines for decommissioning the GA facilities allow an exposure rate of 10 pR/h, above background at 1 m above the surface. All measurements satisfy the established guideline.

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NRC surface contamination guidelines for release of facilities for unrestricted use are presented in Appendix C.

The guidelines for residual activity containing uranium, and its daughter products and for mixed fission I

products for comparison are:

2 2

5000 dpm/100 cm, averaged over 1 m area 2

15000 dpm/100 cm, maximum in a 100 cm2 area 2

1000 dpm/100 cm, removable Guidelines for residual tritium activity are:

2 2

20,000 dpm/100 cm, averaged over 1 m area 2

60,000 dpm/100 cm, maximum in a 100 cm2 area 2

4.,000 dpm/100 cm, removable Surface measurements for total alpha and beta-gamma activity in Building 2 and Building 9,

did not exceed the established guideline values for uranium.

Tritium activity was well below the guideline values. Removable alpha and beta activity was negligible on all smears..For the most part, measurements were below the detection limitations of the procedures.

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SUMMARY

I At the request of the NRC Region V Office, in October 1989 the Environmental Survey and Site Assessment Program of ORAU performed confirmatory I

surveys of Building 2 " Group 4" rooms and of " Stage 2" rooms in Building 9.

The survey consisted of alpha, beta-gamma, and gamma scans of the floor and wall surfaces, exposure rate measurements, direct measurements for total and removable activity, and analysis of drain residue samples. No significant fixed or removable surface activity was detected. Elevated levels of U-235 and' U-238 were measured in the drain samples collected from Rooms 317 and 355/357.

The licensee responded by removing all remaining residue from the drains, and a follow-up survey by the State of California, Department of Health Services Radiological Health Branch confirmed the effectiveness of the additional I

cleanup.

Based on the survey findings, it is ORAU's opinion that the " Group 4" and " Stage 2"

rooms in Building 2 and 9, respectively, meet the guidelines established by NRC for release to unrestricted use.

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9 i

METERS I

I FIGURE 18: Layout of Room 41, Indicating Locations of Surface Measurements g

27 I

CAT 4a DEL MAR PACIFIC CCAST HWY.

GENERAL ATOMICS h3 7 FACILITIES (g

\\

/6 CENESEE AVE.

I

/

MIRAMAR y

5 5

D b

E UNIVERSITY S

CITY QU I

\\

LA JOUA

}

j i

4 1G PACIFIC exc;7;c OCEAN BEACH PAISSION j

l SAN

[

IEGO vg N

i I

A e MEASUREMENT LOCATIONS MILES db I

r 0

1 2

3 4

5 m-m 0

2 4

6 8

KILOMETERS b

E FIGURE 19: Locations of Background Measurements from the Vicinity of General Atomics I

8

TABLE 1 BACKGROUND RADIATION LEVELS I

GENERAL ATOMICS SAN DIEGO, CALIFORNIAa I

Gamma Exposure Rates Gamma Exposure Rates I

at 1 m Above the Surface at the Surface Locationb (pR/h)

(gR/h) 1 7

8 4

2 8

8 3

7 7

I.

4 10 10 5

13 15 6

13 15 Range 7 to 13 7 to 15 Average 10 11 aData obtained during confirmatory survey of phase I decommissioning activities (1-)

DRefer to Figure 19.

t f

29

'M M

M

~

a TABLE 2 SUM 4ARY OF SURFACE ACTIVITY MEASUREMENTS BUILDING 2. L BUILDINO COMPLEX GENERAL ATOMICS SAN DIEGO, CALIFORNIA

1. OF GRID BLOCKS HIGHEST GRID ROOM OR BLOCK AVERAGE TOTAL ACTIVITY REMOVABLE ACTIVITY 9 2

2 2

OR LOCATIONS (dpm/100 cm )

(dpm/100 cm )

(dpm/100 cm )

AREAa LOCATION MEASURED ALPHA BETA ALPHA RANGE BETA-GAMMA RANGE ALPHA RANGE BETA-GAMMA RANGE b

317 Floor 2

<25 1100

<25 430-1800

<3

<6 b

Lower Walls 2

<25 850

<25-37

<410-1300

<3-3

<6 Upper Walls &

d Ceiling 2c N/A N/A

<25

<410

<3-5

<6 Miscellaneous 1C (drain)

N/A N/A

<410

<3

<6 ta b

O 317 Floor l jge

<25

<410

<25

<410

<3

<6 Mezzanine Lower Walls 3c N/A N/A

<25

<410- 480

<3

<6 Miscellaneous Ic (sink)

N/A N/A

<25 690

<3

<6 f

b 5 j4c 40 480

<25-190

<410- 800

<3-3

<6 355/357 Floor b

Lower Walle 3

150

<410

<25-450

<410- 430

<3-3

<6-6 Upper Walle &

Ceiling 4c N/A N/A

<25-60

<410

<3-7

<6-7 Miscellaneous Ic N/A N/A 88 1400

<3

<6 f

b 5 j4c 09 750

<25-140

<410-1280

<3

<6-10 359/361 Floor b

Lower Walls 5

120

<410

<25-160

<410- 450

<3-3

<6-7 Upper Walls &

c Ceiling 4

N/A N/A 36-980

<410-5000

<3-5

<6-9 f

D 3 /4c 27

<410

<25-830

<410-1100

<3-21

<6-18 359/361 Floor b

Mezzanine Lower Walls 2 /2c 130

<410 45-240

<410

<3-9

<6-6 Upper Walls &

Ceiling Ic N/A N/A 45

<410

<3

<6

M M

M

. M M

M M

M M

TABLE 2 (continued)

SUW ARY OF SURFACE ACTIVITY MEASUREMENTS 3UILDING 2. L BUILDING COMPLEX GENERAL ATOMICS SAN DIEGO. CALIFORNIA 8 0F GRID BLOCKS HIGHEST G! TID ROOM OR O'0CK AVERAGE TOTAL ACTIVITY REMOVABLE ACTIVIT8 OR LOCATIONS (dpm/100 cd)

(dpm/100 cm )

(dpm/100 cm )

2 2

AREAa LOCATION MEASURED ALPHA BETA ALPHA RANGE BETA-GAMMA RANGE ALPHA RANGE BETA-GAMMA RANGE f

D 544/556 Floor S /4 c

<25 1400

<25-44

<410-1600

<3-3

<6-12 b

Lower Walls 5

62 770

<25-98

<410-1100

<3-3

<6-6 Upper Walls &

C Ce il ing 2

N/A N/A

<25-71

<410- 640

<3-3

<6 558 Floor Y/bc

<25 750

<25 410-1400

<3

<6 b

Lower Walls 2

<25

<410 (25-35

<410- 850

<3

<6-7 y

Upper Walls &

C Ceiling I

N/A N/A 38

<410

<3

<6 b c 560 Floor 2 f4 28 680 (25-56

<410-1400

<3

<6-8 D

Lower Walls 2

<25 410

<25-38

<410- 640

<3

<6-6 Upper Walls &

Ceiling 2c N/A N/A

<25

<410 3

46-- 9 f

b 562/564 Floor S

<25 1400

<25 560-1500

<3

<6 Lower Walla Y

(26 1200

<25-88

<410-1300

<3-3

<6 Upper Walls &

Ceiling 6c N/A N/A

<25-38

<410-1100

<3-3

<6-7

%efer to Figures 8 to 16.

bFive point measurement.

c ingle point measurement.

S b/A: Not Applicable, e- : measurement not performed, crea too small to acco mocate probe.

IRooms were gridced together.

%emovable H-3' activity for tall smears was < 70 com/100 cm2

M M

M M

M M

M M

M TABLE 3 RADIONUCLIDE CONCENTRATIONS IN RESIDUE SAMPLES SUILDING 2 L BUILDING COMPLEX GENERAL ATOMICS SAN DIEGO. CALIFORNIA RADIONUCLIDE CONCENTRATIONS (pCi/g)

ROOM" GRID LOCATION Co-60 Cs-137 U-235 U-238 Th-228 Th-232 b

317 B. 2

<2.0 2.1 1 1.3 1.3 1 1.2 25 i 14 2.3 1 1.8

<6 355/357 A+1.5, 1.8

<7.0 2.9 i 2.6 22 i 18 120 1 28 7

i 4 23 1 13 ta aRefer to Figures 8 and 10.

buncertainties represent the 95% confidence levels. based only on counting statistics; additional laboratory uncertainties of i 6 to 10% have not been propagated into these data.

n

-.m.m m m.2 m.-

as..w p

.qr w-3 y.

y

M M

M M

M

~

M M

'M M

- M TABLE 4

SUMMARY

OF SURFACE ACTIVITY MEASUREMENTS BUILDING 9. E BUILDING COMPLEX GENERAL ATOMICS SAN DIEGO, CALIFORNIA 5 0F GRID BLOCKS HIGHEST GRID ROOM OR BLOCK AVERAGE TOTAL ACTIVITY REMOVABLE ACTIVITY 2

2 2

OR LOCATIONS (dpm/100 cm )

(dom /100 cm )

(dpm/100 cm )

AREAa LOCATION MEASURED ALPHA BETA ALPHA RANGE BETA-GAMMA RANGE ALPHA RANGE BETA-GAMMA RANGE b

40 Floor 2 ygc 430 990

<25-1200

<410-2300

<3-5

<6 b

Lower Walls 2

<25

<410

<25

<410

<3-3

<6 d

Upper Walls 1C N/A N/A

<25

<410 5

<6 bi ygc 270 720

<25-510

<410-1300

<3

<6-7 41 Floor

%efer to Figures 17 and 18.

hivepointmeasurement.

cSingle point measurement.

h/A;NotApplicable.

... ~.

E I

lI REFERENCES 1.

" Confirmatory Survey of Phase 1 Decommissioning, Former Waste Processing lI Facility, GA Technologies, San Diego, California," Oak Ridge Associated Universities, July 1986.

I 2.

" Confirmatory Survey of Phase II Decommissioning, Former Waste Processing

Facility, GA Technologies, San Diego, California," Oak Ridge Associated Universities, March 1987.

3.

" Confirmatory Survey of Phase III Decommissioning, GA Technologies, San Diego, California," Oak Ridge Associated Universities, February 1988.

4.

" Confirmatory Survey of Phase IV Decommissioning, General Atomics, San Diego, California," Oak Ridge Associated Universities. November 1988.

j 5.

" Confirmatory Survey of Facilities in Buildings 2 and 9, General Atomics, 3

San Diego, California," Oak Ridge Associated Universities, July 1989.

6.

General Atomics.

Decontamination of Selected General Atomics Science I

Laboratories For Release To Unrestricted Use (Group 4), San Diego, California, September 12, 1989.

7.

General Atomics.

Decontamination of the " Hot Suite" Area of the TRIGA Fuel Fabrication Facility Formerly Located in Building 9 For Release To j

Unrestricted Use, Stage 2, San Diego, California, August 31, 1989.

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I APPENDIX A

I MAJOR SAMPLING AND ANALYTICAL EQUIPMENT j

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APPENDIX A MAJOR SAMPLING AND ANALYTICAL EQUIPMENT The display or description of a specific product is not to be construed as I

an endorsement of that product or its manufacturer by the authors or their employer.

t A.

Direct Radiation Measurements j

Eberline " RASCAL" g

Portable Ratemeter-Scaler g

Model PRS-1 (Eberline, Santa Fe, NM)

I Eberline PRM-6 Portable Ratemeter l

(Eberline, Santa Fe, NM)

Eberline Alpha Scintillation Detector j

Model AC-3-7 (Eberline, Santa Fe, NM)

Eberline Beta-Camma " Pancake" Detector Model HP-260 (Eberline, Santa Fe, NM) f Victoreen NaI Scintillation Detector i

Model 489-55 (Victoreen, Cleveland, OH) f Ludlum Alpha-Beta Floor Monitor j

)

Model 239-1 (Ludlum, Sweetwater, TX) l l

I Ludlum Portable Ratemeter-Scaler Model 2220

{

(Ludlum, Sweetwater, TX)

B.

Laboratory Analyses I

l Automatic Low Background Alpha-Beta Counter Model LB-5110 (Tennelec, Oak Ridge, TN)

B l

A-1 r

i i

E f

B f

Liquid Scintillation Counter I

Model Tri-Carb 300 (Packard Instrument Company, Downers Grove, IL) f High-Purity Germanium Detector I

Model GMX-23195-S, 23% efficiency l'

(EG&G ORTEC, Oak Ridge, TN)

I Used in conjtmetion with:

Lead Shield, C-16 I

(Gamma Products, Inc., Palos Hills, IL)

Multichannel Analyzer ND-66/ND-680 System (Nuclear Data Inc., Schaumburg, IL) 1 I

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I A-2 B

B

- _. =

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i lE APPENDIX B 7

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MEASUREMENT AND ANALYTICAL PROCEDURES e

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APPENDIX B E

MEASUREMENT AND ANALYTICAL PROCEDURES I

Surface Scans I

Surface scans were performed by passing the probes slowly over the surface; the distance between the probe and the surface was maintained at a minimum - nominally about 1 cm.

Identification of elevated levels was based on increases in the audible signal from the recording or indicating instrument.

Scans of large surface areas on the floor of the facility were accomplished by 2 sensitive area.

The use of a gas proportional floor monitor, with a 550 cm detector was slowly moved in a systematic pattern to cover 100% of the accessible floor area.

Other surfaces were scanned using smaller, hand-held detectors.

Combinations of detectors and instrument for the scans were:

I Beta-Gamma - Pancake GM probe with PRM-6 ratemeter.

Beta-Gamma - Pancake GM probe with PRS-1 scaler /ratemeter.

Gamma

- Na1 scintillation detector (3.2 cm x 3.8 cm crystal) with PRM-6 ratemeter.

Alpha-Beta - Gas Proportional Floor Monitor with Ludlum Model 2220 Scaler /ratemeter Alpha and Beta-Gamma Surface Measurements

W Measurements of total alpha activity levels were performed using Eberline Model PRS-1 portable scaler /ratemeters with Model AC-3-7 alpha scintillation probes.

Measurements of total beta-gamma activity levels were performed using Eberline Model PRS-1 portable scaler /ratemeters with Model HP-260 thin-window

" pancake" G-M probes.

Count rates (cpm) were converted to disintegration rates 2

I (dpm/100 cm ) by dividing the net rate by the 4 x efficiency and correcting for the active area of the detector. Effective window areas were 59 cm2 for the.

I B-1 l

5

)

a

I I

ZnS detectors and 15 c=2 for the GM detectors. The background count rate for ZnS alpha probes averaged approximately 2 cpm; the average background count rate was approximately 40 cpm for the G-M detectors.

I Removable Activity Measurements Smears for determination of removable activity were performed using numbered filter paper disks, 47 mm in diameter; smears were sealed in labeled envelopes with the locations and other pertinent information recorded. The smears were returned to laboratories in Oak Ridge and counted on a low-background gas-proportional counter for gross alpha and gross beta activity. The removable tritium activity level was determined by cutting smear paper into small 6 mm pieces and placing them into a liquid scintillaticn i

" cocktail."

An unused smear was used to correct for background, and another was spiked with an NIST traceable tritium standard to provide an internal I

calibration factor and compensate for instrument drift. All samples were counted on a Model Tri-Carb 300 liquid scintillation counter.

Residue Sample Analysis I

Residue samples were dried, mixed, and an aliquot sealed in an appropriate container, chosen to reproduce the calibrated counting geometry.

Samples were counted on intrinsic germanium detectors coupled to a Nuclear Data Model ND-680 pulse height analyzer system. Background and Compton stripping, peak search, I

peak identification, and concentration calculations were performed using the computer capabilities inherent in the analyzer system.

Energy peaks for radionuclides of concern were:

Co-60 1.173 MeV Cs-137 0.662 MeV U-235 0.144 MeV I

U-238 0.094 MeV from Th-234 (secular equilibrium assumed)

Th-232 0.911 MeV from Ac-228 (secular equilibrium assumed)

B-2 5

I

-I Spectra were also reviewed for the presence of other radionuclides.

I Uncertainties and Detection Limits I

The uncertainties associated with the analytical data presented in the tables of this report, represent the 95% confidence levels for that data.

I These uncertainties were calculated based on both the gross sample count levels and the associated background count levels. When the net sample count was less than the 95% statistical deviation of the background count, the sample concentration was reported as less than the detection limits of the measurement procedure.

Because of variations in background levels, sample volumes or

weights, measurement efficiencies, and Compton contributions from other 1

radionuclides in samples, the detection limits differ from sample to sample and instrument to instrument.

Additional uncertainties of i 6 to 10%,

j associated with sampling and laboratory procedures, have not been propagated

)

i into the data presented in this report.

Calibration and Quality Assurance Laboratory and field survey procedures are documented in manuals developed specifically for the Oak Ridge Associated Universities' Environmental Survey l

and Site Assessment Program.

With the exception of the measurements conducted with portable gamma I

scintillation survey meters, instruments were calibrated with NIST-traceable standards.

The calibration procedures for the portable gamma instruments are performed by comparison with an NIST calibrated pressurized ionization chamber.

l Quality control procedures on all instruments included daily background I

and check-source measurements to confirm equipment operation within acceptable statistical fluctuations.

The ORAU laboratory participates in the EPA and DOE /EML Quality Assurance Programs.

l l

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APPENDIX C l

GUIDELINES FOR DECONTAMINATION OF FACILITIES AND EQUIPMENT PRIOR TO RELEASE FOR UNRESTRICTED USE OR TERMINATION OF LICENSES FOR BY-PRODUCT, SOURCE OR SPECIAL NUCLEAR MATERIAL I

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.E.

GUIDELINES FOR DECONTAMINATION OF FACILITIES AND EQUIPMENT FRIOR TO RELEASE FOR UNRESTRICTED USE OR TERMINATION OF LICENSES FOR BYPRODUCT, SOURCE,

^

OR SPECIAL NUCLEAR MATERIAL j

- A i

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I U.S. Nuclear Regulatory Commission Divison of Fuel Cycle & Material Safety I

Washington, D.C.

20555 I

t I

I July 1982 I

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I

g The instructions in this guide, in conjunction with Table 1, specify l3 the radionuclides and radiation exposure rate limits which should be used in decontamination and survey of surfaces or premises and equipment prior to abandonment or release for unrestricted use.

The limits in Table 1 do

.I not apply to premises, equipment, or scrap containing induced radioactivity for which the radiological considerations pertinent to their use may be different. The release of such facilities or it2ms from regulatory _ control is considered on a case-by-case basis.

1.

The licensee shall make a reasonable effort to eliminate residual contamination.

2.

Radioactivity on equipment or surfaces shall not be covered by paint, plating, or other covering material unless contamination levels, as I

determined by a survey and documented, are below the limits specified in Table 1 prior to the application of the covering.

A reasonable effort must be made to minimize the contamination prior to use of any covering.

3.

The radioactivity on the interior surfaces of pipes, drain lines, or ductwork shall be determined by making measurements at all traps, and other appropriate access points, provided that contamination at these locations is likely to be representative of contamination on the interior of the pipes, drain lines, or ductwork.

Surfaces or I

premises, equipment, or scrap which are likely to be contaminated but are of such size, construction, or location as to make the surface inaccessible for purposes of measurement shall be presumed to be contaminated in excess of the limits.

4.

Upon request, the Commission may authorize a licensee to relinquish lg possession or control of premises, equipment, or scrap having surfaces (3

contaminated with materials in excess of the limits specified.

This may include, but would not be limited to, special circumstances such lg as razing of buildings, transf er of premises to another organization lg continuing work with radioactive materials, or conversion of i

facilities to a long-tenn storage or standby status.

Such requests must:

l us a.

Provide detailed, specific information describing the premises, equipment or scrap, radioactive contaminants, and the nature, en ent, and degree of residual surface contamination.

l b.

Provide a detailed health and safety analysis which reflects that l

the residual amounts of materials on surface areas, together with j

other considerations such as prospective use of the premises, equipment or scrap, are unlikely to result in an unreasonable ~

l risk to the health and safety of the public.

lI S.

Prior to release of premises for unrestricted use, the licensee shall make a

comprehensive radiation survey which establishes that contamination is within the limits specified in Table 1.

A copy of

I C-1

I

I-the survey report shall be filed with the Division of Fuel Cycle and Material

Safety, USNRC, Washington, D.C.

20555, and also the I

Administrator of the NRC Regional Office having jurisdiction.

The report should be filed at least 30 days prior to the planned date of abandonment. The survey report shall:

Identify the premises.

a.

b.

Show that reasonable effort has been made to eliminate residual I

contamination.

Describe the scope of the survey and general procedures followed.

c.

d.

State the findings of the survey in units specified in the l

instruction.

Following review of the report, the NRC will consider visiting the I

facilities to confirm the survey.

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TABLE 1 ACCEPTABLE SURFACE CONTAMINATION LEVELS Nuclidesa Averageb,c,f flaximumb,d,f Removableb,e f 2

2 1,000 dpm a/100 cm U-nat, U-23 5, U-23 8, and 5,000 dpm a/100 cm2 15,000 dpm a /100 cm associated decay products 2

Transuranics, Ra-226, Ra-22 8, 100 dpm/100 cm2 300 dpm/100 cm2 20 dpm/100 cm Th-23 0, Th-22 8, Pa-231, Ac-227, 1-125, 1-129 2

2 200 dpm/100 cm Th-nat, Th-232, Sr-90, Ra-223 1000 dpm/100 cm2 3000 dpm/100 cm Ra-224, U-232, 1-126, 1-131, I-133 2

2 1000 dpm Sy/100 cm 2

15,000 dpm Sy/100 cm 9

Beta-gamma emitters (nuclides 5000 dpm Sy/100 cm with decay modes other than w

alpha emission or spontaneous fission) except Sr-90 and others noted above.

l a Where surface contamination by both alpha-and beta-gamma-emitting nuclides exists, the limits established for alpha-and beta-gamma-emitting nuclides should apply independently.

b As used in this table, dpm (disintegrations per minute) means the rate of emission by radioactive material as determined by correcting the counts per minute observed by an appropriate detector for background, efficiency, and geometric factors associated with the instrumentation.

!!casurements of average contaminant should not be averaged over more than I square meter. For objects C

of less surface area, the average should be derived for each such object.

2 d the maxi:aum contamination level applies to an area of not more than 100 cm,

2 of surface area should be determined by e The amount of removable radioactive material per 100 cm wiping that area with dry filter or soft absorbent paper, applying moderate pressure, and assessing the amount of radioactive material on the wipe with an appropriatc instrument of known efficiency. When removable contamination on objects of less surf ace area is determined, the pertinent levels should be reduced proportionally and the entire surface should be wiped.

f The average and maximum radiation levels associated with surf ace contamination resulting f rom beta-gamma emitters should not exceed 0.2 mrad /h at I cm and 1.0 mrad /h at I cm, respectively, measured through not more than 7 milligrama per square centimeter of total absorber.

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l APPENDIX D j

l STATE OF CALIFORNIA DEPARTMENT OF HEALTH SERVICES CRITERIA FOR RELEASE OF FACILITIES AND EQUIPMENT l

TO UNRESTRICTED USE l

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{

ACCEPTABLE SURFACE CONTAMINATION LEVELS I

(

NUCLIDEa AVERAGE,c MAXIMUM,d REMOVABLE,e j

b b

b 2

2 2

(dpm/100 cm )

(dpm/100 cm )

(dpm/100 cm )

J l

1)

U-nat, U-235, U-238 5,000 15,000 1,000 and associated decay products j

2) Transuranics, Ra-226, 100 300 20 Ra-228, Th-230, Th-228, Pa-231, Ac-227, I-125, l

I-129 l

3)

Th-nat, Th 232, Sr-90, 1,000 3,000 200 1

Ra-223, Ra-224, U-232, I-126, I-131, 1-133

4) Beta-gamma emitters 5,000 15,000 1,000 I

(nuclides with decay modes other than alpha emission or spontaneous I

fission) except Sr-90 and others noted above.

5)

H-3, C-14 except as DNA 20,000 60,000 4,000 I

f precursors I

aHere surface contamination by both alpha-and beta-gamma-emitting nuclides

exists, the limits established for alpha-and beta-gamma-emitting nuclides should apply independently.

bIs used in this table, dpm (disintegrations per minute) means the rate of emission by radioactive material as determined by correcting the counts per I

minute observed by an appropriate detector for background, efficiency, and geometric factors associated with the instrumentation.

I cMeasurements of average contaminant should not be averaged over more than 1 square meter.

For objects of less surface area, the average should be derived for each such object.

2 dThe maximum contamination level applies to an area of not more than 100 cm,

2

• The amount of removable radioactive material per 100 cm of surface area should be determined by wiping that area with dry filter or soft absorbent

paper, applying moderate pressure, and assessing the amount of radioactive I

m

I I

material on the wipe with an appropriate instrument of known efficiency. When removable contamination on objects of less surface area is determined, the pertinent levels should be reduced proportionally and the entire surface should be wiped.

fDNA precursors mean molecules or compounds that are directly incorporated into the DNA molecule during DNA biosythesis, e.g. purine and pyrimidine bases and their

analogs, nucleotides and nucleosides.

The acceptable surface I

contamination levels for H-3 and C-14 in DNA precursors are as tabulated in paragraph (d) for beta-gamma-emitters.

I USNRC Regulatory Guide 1.86 Termination of Operating Licenses for Nuclear Reactors, Washington D.C. (June 1974)

ANSI, Control of Radioactive Surface Contamination on Materials, Equipment and I

Facilities To Be Released for Uncontrolled Use, final draft, proposed American National Standard N-328, Atomic Industrial Forum, Inc., N.Y.

(June 1974)

Atomic Industrial Forum, Inc., N.Y.

(June 1974)

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A,ENo1x e LETTER Fh.1 3. R. TAMPLIN AND C. WONG I

(STATE OF CALIFORNIA DEPARTMENT OF HEALTH SERVICES) TO K. WONG (STATE OF CALIFORNIA DEPARTMENT OF INDUSTRIAL REIATIONS DIVISION OF OCCUPATIONAL SAFETY AND HEALTH RADIATION HEALTH UNIT)

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3 I

m t

t SfoTE OF CAttrORNIA-HfALTH AND WELFARE AGerdY GEORGE DEUKMEJtAN. Governor DEPARTMENT OF HEALTH SERVICES g

A c1S1 BIRKELEY WAY

?.*

3 pERKELEY, CA 94704 Kim Won $

November 28, 1989 State of California Dept. of Industrial Relations Div. of Occup. Safety & Health g g { h h.D T Radiation Health Unit (q g-Wo w okC EV G150 Van Nuys. Room 405 Van Nuys. CA 91401-3379 b

Dear Mr. Wong,

i Included are the results for the samples taken at General Atomics on October 25, 1939.

We received one sewage effluent sample and three packages of wipe samples. Two of the packages for wipe samples, Bldg. 2/ rooms 554/558/500 and Bldg.2/ rooms 317-throat pipe, contained three wipe samples ench.

The third package Bldg. 2/ room 317. did not contain any samples.

j The sewage effluent sample was gamma reanned as received for 500 minuten.

No gamma emitters over the lower level of detection were found.

After gamma scanning, a small portion of the sewage effluent sample was evaporated on a 2" stainless steel planchet.

This planchet was counted in an Internal proportional counter for gross alpha and in a low background counter for gros. beta.

The results for these analyses are shown below.

The two packages of wipe samples were gamma scanned together as a batch for 500 minutes. Again no gamma emitters over the lower level of detection were found.

The wipe samples were then individually mounted on a 2" plastic planchet and covered with a thin :aylar film.

These samples were counted on a low background counter for both alpha and beta. The results are as follows:

SRL:

R:

Sa n:p l e ID Gross Alpha pci/ Liter Gross Beta.pcl/ Lit-r C 5 ~s G 13017 Sewage Eff.

39.4 +/- 23.2

-35.9 4/- 53.0 no gamma emitters over the lower level of detection for a 500 minute scan.

NRI:

R#

Sample TD Grnns Alpha,pCi/ Wine Gross ho r o, pc i / Wi p..

6558 13319 Room 554&556 0.8 +/- 0.C 0.0 -/- 0.3 Room 558 0.5 +/- 0.5 0.3 +/- 0.3 Room 500 0.1 +/- 0.3 0.1 +/- 0.2 G559 13020 Room 317 Floor 0.7 +/- C.4 0.4 +/- 0.2 Room 317 pipe

-0.1

+/- 0.4 0.0 +/- 0.3 Room 314 0.0 +/- 0.4

-0.1 +/- 0.2 B. R. Tamplin, Ph.D., Chief Sanitation & Radiation Laboratory gM Carolyn Wong Public Health Chemist E-1

\\'2-r

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