ML20196J818

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Confirmatory Radiological Survey,Bldg 400,Vallecitos Nuclear Ctr,Ge,Pleasanton,Ca, Final Rept
ML20196J818
Person / Time
Site: 07000754
Issue date: 02/29/1988
From: Cotten P
OAK RIDGE ASSOCIATED UNIVERSITIES
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20196J794 List:
References
CON-FIN-A-9076-3 ORAU-88-B-87, NUDOCS 8803150066
Download: ML20196J818 (54)
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{{#Wiki_filter:. - - -. _ k ORAU 88/B 87 CONFIRMATORY RADIOLOGICAL SURVEY BUILDING 400 VALLECITOS NUCLEAR CENTER GENERAL ELECTRIC COMPANY PLEASANTON, CALIFORNIA Prepared by P.R. COTTEN Radiological Site Assessment Program !!anpower Education, Research, and Training Division Oak Ridge Associated Universities Oak Ridge, TN 37831-0117 Project Staff J.D. Berger T.J. Sowell R.D. Condra G.L. ifurphy M.A. Edwards C.F. Ueaver D.A. Gibson Prepared for Division of Industrial and Medical Nuclear Safety U.S. Nuclear Regulatory Commission Region V Office Final Report February 1988 This report is based on work performed under Interagency Agreement DOE No. 40-816-83,NRC Fin. No. A-9076-3 between the U.S. Nuclear Regulatory Commission and the U.S. Department of Energy. Oak Ridge Associated Universities performs complementary work under contract nunbe r DE-AC05-760R00033 with the U. S. Department of Energy. k DO K [ C

TABLE OF CONTENTS Page List of Figures. 11-List of Tables iii Introduction and Site History..................... 1 Site Description I Survey Procedures. 2 Results.. 5 Comparison of Results with Guidelines.. 7 Summary. 8 References 38 Appendices. Appendix A: Major Sampling and Analytical Equipment Appendix B: Measurement and Analytical Procedures Appendix C: Guidelines for Decontamination of Facilities and Equipment Prior to Release for Unrestricted Use or Termination of Licenses for Byproduct, Source, or Special Nuclear Material i l-I i k

CONFIRMATORY RADIOLOGICAL SURVEY BUILDING 400 VALLECITOS NUCLEAR CENTER GENERAL ELECTRIC COMPANY PLEASANTON, CALIFORNIA INTRODUCTION AND SITE HISTORY Beginning in the mid 1970's, portions of Building 400 at the General Electric (GE) Vallecitos Nuclear Center (VNC) were used for pilot plant process studies on nuclear reactor fuels. The operations, conducted under license SNM-960 f rom the Nuclear Regulatory Commission (NRC), utilized kilogram quantities of unir adiated natural, depleted and enriched (<4% U-235) uranium in various compounds and forms; small amounts of Gd-153 were also used in some processes. GE has terminated the use of radioactive material in Building 400 and has performed decontamination of the facilities. A radiological survey of the building performed by GE, indicated that the decontamination was effective in reducing contamination to acceptable levels for release f rom licensing restrictions. I At the request of the NRC, Region V Office, the Radiological Site Assessment Program of Oak Ridge Associated Universities conducted a radiological survey to confirm the facility status relative to the NRC criteria for release for unrestricted use. SITE DESCRIPTION The VNC is located on Vallecitos Road in Pleasanton, California (Figure 1). Building 400 is located in the north eastern portion of the VNC complex (Figure 2). Radioactive material use was confined to 4 rooms in the southern j portion of the building: the chemical laboratory, the uranium oxide powder room, the machine shop / assembly area, and the high-bay area where most of the pilot plant experiments were performed (Figures 3 and 4). All process equipment, ventilation systems, and potentially contaminated piping and electrical wiring. were removed f rom the areas; much of the floor covering also had been removed. On the west side of the building is a storage shed and an enclosed metal siding shed, used for cylinder storaget north of the metal shed is an empty storage tank, To the east of Building 400 is the exhaust ventilation unit for the facilities. 1 L

(. The Chemical Laboratory (Room 114) has a floor area of approximately 1500-2 square feet (139 m ); it served as a uranium chemistry laboratory. Room 115, 2 known as the powder room, is 100 square feet (9 m ) and was used for grinding and milling uranium powders and for powder transfer. The machine shop / assembly area 2 (Room 129) is 1200 square feet (110 m ) and was used for construction and repair of equipment, and for the storage of uranium. The high bay area (Room 130) contained pilot plant scale process equipment; it is approximately 500 square feet in area and 30 feet high. Construction is of steel beams and metal siding. The concrete floor has been removed to expose surface soils. All other laboratory areas in Building 400 were designated for non-radioactive material operat.;ons. SURVEY PROCEDURES The confirmatory survey of Building 400 of the VNC was performed during the period of August 7-13, 1987, by the Radiological Site Assessment Program of Oak Ridge Associated Universities (0RAU). The survey was conducted in accordance with a plan, prepared by ORAU and submitted to the NRC's Region V Office. 2 Objective The survey objective was to verify the licensee's survey findings by measuring surface contamination levels and coaparing the results with the appropriate h1C guidelines. Procedures Document Review The final survey results, prepared by GE, were reviewed. Data were compared to guidelines for release of facilities from licensing restrictions. Facility Survey Gridding An alpha numeric 2 m x 2 m reference grid system was established on the floor r and lower walls (up to 2 m) of rooms 114, 115, and 129 and the high-bay area 2 +>v 7

LIST OF FIGURES .P__ag_e, FIGURE 1: Pleasanton, California, Area Indicating the Location of the Vallecitos Nuclear Center, General Electric Company.. 9 FIGURE 2: Building 400 and Surrounding Area. 10 FIGt!RE 3: Building 400 Room Layout 11 FIGURE 4: Surveyed Portion of Building 400, Indicating the Floor Grid Established for Reference. 12 FIGURE 5: Contamination Measurement Locations on the Floor and Lower Walls of Room 114... 13 FIGURE 6: Contamination Measurement Locations on the Floor and Lower Valls of Room 115.. 14 FIGURE 7: Contamination Measurement Locations on the Floor and Lower Walls of Room 129.. 15 FIGURE 8; Contamination Measurement Locations on the Lower Walls of High Bay Area (Room 130) 16 FIGURE 9: Measurement Locations on Upper Valls, Ceiling, and Overhead Surfaces of Room 114. 17 FIGURE 10: Measurement Locations on Upper Valls, Ceiling, and Overhead Surfaces of Room 115. 18 FIGURE 11: Measurement Locations on Upper Walls, Ceiling, and Overhead Surfaces of Room 129... 19 FIGURE 12: Measurement Locations on Upper Ualls, Ceiling, and Overhead Surfaces of the High Bay Area (Room 130). 20 FIGURE 13: Drain Line Contamination Measurement Locations 21 FIGURE 14: Building 400 Paint Sampling Locations. 22 23 FIGURE 15: Indoor Soil Sampling Locations FIGURE 16: Floor Tile and Concrete Sampling Locations 24 FIGURE 17: Locations of Exposure Rate Measurements and Soil Sampling.. 25 FIGURE 18: Outside Ventilation System Indicating Sampling Locations 26 l

  • /IGURE 19: Locations of Residual Contamination Identified by Surface.

27 Scans 11

LIST OF TABLES

Page, TABLE 1:

Summary of Surf ace Contamination Measurements of Building 400.......... .28 TABLE 2: Summary of Surf ace Contamination Measurements In Bsilding 400 Drain Lines 30 TABLE 3: Radionuclide Concentrations in Soil Samples Collected Inside Building 400 31 TABLE 4: Results of Analyses of Paint Samples Co13ected From Building 400. 32 TABLE 5: Summary of Radionuclide Concentrations in Floor Tile and' Concrete-Samples Collected From Building 400 33 TABLE 6: Exposure Rates Outside Building 400 34 TABLE 7: Summary of Surface Contamination Measurements on Building 40(/ Outside Ventilation Systems.. 35 TABLE 8: Radionuclide Concentrations in Soil Collected Outside Building 400 36 TABLE 9: Radionuclide Concentrations in Surface Cravel Samples Collected From The Roof of Building 400 37 l l-l l r i 111 4

i 9 (Figures 5-8). The grid origin (A, 0) was in' the southwest corner of room '114. Measurements on the upper walls and ceilings were referenced to the floor grid designation. Surface Scans Alpha, be ta-gamma, and gamma scans were pert'ormed on floors, using an alpha / beta gas-proportional floor monitor and NaI(T1) gamma scintillation detectors with audible indicatind scaler /ratemeters. Surfaces not accessible to the floor monitor, i.e., walls, ceilings, and overhead areas such as ledges, beams, piping, fixtures, counter tops, equipment, and ductwork were scanned using portable ZnS alpha scintillation and "Pancake" GM and beta-gamma detectors. Areas indicating elevated radiation levels were marked for udditional measurements. Measurement of Surf ace Contamination Levels Approximately 10% of the grid blocks on the floor and lower walls of each room were randomly selected for surface contamination measurements. Due to the small area, 100% of the grid blocks in room 115 were surveyed. Blocks selected for these measurements are indicated on Figures 5-8. In each grid block surveyed, direct measurements of alpha and be ta-gamma contamination levels were systematically performed at the center and four equidistant points, midway between the center and block corners. Smears for removable alpha and beta contamination were performed at that location in each grid block, where the highest direct level was obtained. Forty-two locations on upper walls, ceilings, fixtures, and equipment were also selected for single-point measurements of total and removable alpha and beta-gamma contamination levels. These locations are identified on Figures 9-12. Direct measurements and/or smears were also obtained f rom locations identified by surface scans and inside drains (Figure 13). Exposure Rate Measurements Gamma exposure rates were measured throughout the southern portion of Building 400, using NaI scintillation probes. 3

Miscellaneous Samples Paint samples were collected from 100 cm2 areas at six locations on the walls of rooms 114, 115, and 129 (Figure 14). Soil samples were collected from areas in rooms

114, 115, ~ 129 and the high-bay, where the floor had been removed (Figure 15).

Samples of floor cile, drain residue, and foundation concrete were collected from the facility (Figure 16). Outside Area Survey Surface Scans Surface scans of the outside areas within 10 m of the building were performed using NaI(TI) gamma scintillation detectors coupled to ratemeters, with audible indicators. Exposure Rate Measurements Exposure rates were measured at I m above the surface at 6 locations outside Building 400 (Figure 17), using Na1 gamma scintillation detectors. Other Measurements and Sampling Six soil samples were collected on the outside property bordering Building 400 (Figure 17). Gravel was collected f rom the facility roof, near or underneath ventilation system ducting. Smears for removable contamination were obtained at two locations inside the exhaust ventilation equipment. Locations of these gravel samples and smears are shown on Figure 18. Sample Analysis and Interpretation of Results Soil, gravel, concrete chips, floor tile, and paf nt samples were analyzed by, gamma spectroscopy, and the spectra were reviewed for identifiable photopeaks' attribu.shle to VNC operations (U-235, U-238, etc.). Smears for the determination of removable contamination were analyzed for gross alpha and beta concentrations. Additional information concerning major instrumentation, sampling equipment. and analytical procedures is provided in Appendices A and B. 4

c. Results were compared with NRC guidelines, established for release of facilites for unrestricted use. These guidelines are presented in Appendix C. RESULTS Dy ument Review ORAU 's review of the survey report, submitted by GE to the NRC, indicates that the procedures 'and instrumentation used were consistent with industry accepted practices; the report did not, however, thoroughly fescribe. the survey plan and survey locations. Followup information or data in the report adequately resolve contaminated or questionable areas indentified by inital surveys. The results of the final surveys support GE's conclusions that the h1C guidelines for i surface contamination were satisfied. Facility Survey 3 Surface Scans Surf ace scans identified several locations of elevated alpha and beta-gamma contamination exceeding guidelines, on or near the floors of the high-bay area. These locations, shown on Figure 19, were brought to the attention of facility personnel; remedial action was performed, and the areas were resurveyed by ORAU. No locations of elevated ganc.a levels were identified in the resurveyed areas. l l Surface Contamination Measurements Table 1 summarizes the results of surface cor.tamination measurements. The l total contamination data presented in this table, are direct. measurements which i include removablo and non-removable activity. Alpha and beta-gamma levels were, for the most part, less than the detection sensitivity of the instruments. The 2 2 maximum alpha and beta-gamma levels were 580 dps/100 cm and 8570 dpm/100 cm,. 2 respectively. Removable alpha activity ranged f rom <3 to 34 dpm/100 cm. The' 2 removable beta activity ranged from <6 to 18 dpm/100 cm, S

Table 2 presents the results of the removable contamination activity from open drain lines in room 114 and 129. Total alpha activity ranged f rom <3 to 2 2 7 dpm/100 cm ; total beta-gamma activity ranged f rom <6 to 10 dpm/100 cm, Exposure Rate !!casurements Exposure rate measurements throughout the laboratories in the south portion of Building 400 ranged f rom 8 to 10 LR/h. Radionuclide Concentrations in !!iscellaneous Samples Concentrations of radionuclides in soil samples collected from excavated floor areas are presented in Table 3. These samples contained from (0.2 to 6.7 pC1/g of U-238; <0.2 to <0.3 pCi/g of U-235; <0.2 pCi/g of Gd-153; <0.1 pCi/g of Co-60 and Cs-137. The radionuclide concentrations measured in paint samples are presented in Table 4. Samples concentrations ranged f rom 4.0 to 67.1 pCi/g of U-238; <1.2 to 5.0 pCi/g of U-235; <0.2 pCi/g of Gd-153; (0.3 to 4,0 Co-60, and <0.3 to 3 pCi/g Cs-137. Results of concrete, ficor and drain tile sample analysis have been tabulated in Table 5. Radionuclide concentrations in floor and drain tile contained from i <1.1 to 28 pCi/g of U-238; <0.2 Cd-153; <0.2 pCi/g to 0.5 pCi/g Co-60, and <0.1 to O.5 pCi/g Cs-137. Concrete samples all contained less than detectable concentrations. i. Outside Area Survey i l Surface Scans The gamma scan of the area surrounding Building 400 identified one elevated location (Figure 17). The area, approximately 7.4 m west of Building 400, had an exposure rate of 117 LR/h on contact with the surface. The licensee was informed-l and decontamination of the area was perf ormed. The exposure rate af ter cleanup I was reduced to 14 pR/h. l 6 l l

r Exposure Rate Measurements Exposure rates measured outside the facility are presented in Table 6. Levels ranged from 10 to 12 pR/h. Other tieasurements and Samples Table 7 presents the results of surf ace contamination measurements performed 2 inside the exhaust system. Total alpha levels were 40 dpm/100 cm and 2 2 45 dpm/100 cm, and beta gamma contamination levels were <360 dpm/100 cm, 2 Removable alpha and beta contamination levels were <3 and 5 dpm/100 cm and 2 7 and 8 dpm/100 cm, respectively. The concentrations of U-238 and U-235, measured in the surface soil samples f rom outside Building 400, (Figure 17), ranged f rom <0.4 to <0.8 pCi/g and <0.2 to <0.3 pCi/g, respectively (Table 8). Gadolinium 153 concentrations were <0.2 pCi/g. The concentrations of Co-60 and Cs-137 ranged f rom (0.1 to 8.7 pCi/g and <0.1 to 0.8 pCi/g, respectively. The NRC establishes soil concentration guidelines on a site specific basis; guidelines for Co-60 are typically in the range of 6-10 pCi/g. Results of gravel samples from the roof of Building 400 are presented in Table 9. For the most part, radionuclide concentrations were below detection limits. The highest radionuelide concentrations measured were U-238, <0.8 pCi/g; U-235, <0.5 pCi/g; Gd-153, <0.2 pC1/g; and Cs-137, 0.8 pCi/g. COMPARISON OF RESULTS WITH GUIDELINES l NRC surface contamination guidelines for release of facilities for unrestricted use are presented in Appendix C. Surface contamination levels 2 t measured by this survey were well below the guidelines of 5000 dpm/100 cm, 2 2 2 2 averaged over 1 m ; 15,000 dpm/100 cm, maximum in 100 cm ; and 1000 dpe/100 cm,. removable. i l 7

Soil sample concentrations were also comparet to the NRC guidelines in Appendix C. A concentration of Co-60 in the range of the typical guideline levels was identified in a sample collected outside Building 400. Cleanup by the licensee was effective in removing the contaminated material and reducing the levels to approximately background levels. All other samples collected were well within NRC guidelines.

SUMMARY

On August 7 through 13, 1987, Oak Ridge Associated Universities performed a confirmatory survey in selected areas of Building 400, of the GE Vallecitos Nuclear Center, in Pleasanton, California. The survey included surface gamma, beta-gamma, and alpha scans, measurement of total and removable contamination 1cvels, and measurement of radionuclide concentrations in soil, paint, tile, gravel, and concrete samples. The findings support the close-out surveys performed by the licensee, and confirm that the radiological conditions satisfy the h7C guidelines established for facilities for release for unrestricted use. 1, i i i l 8 j .m.

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FIGURE t Pleasanton, California, Area Indicating the Location of the Vollecitos Nuclear Center, General Electric Company

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EAR THEN ll WALL x FENCE FIGURE 2: Building 400 and Surrounding Area 10 I

ctv2 l [ ( '1 13 102 1 101 103A 3 105 1-7 104 113 109 115 106A 117 106 119 121 108 xg 123 Ad 125 AA 110/u 2 ELECTRICAL EQUlPWENT 127 l ( 129 11 4 N u 11 5 I I HICH BAY j 130 FIGURE 3: Building 400 Room Layout 11

CEV4 r_3 CORRIDOR 10 8 6 ROOu 11 4 ROOM 129 4 2 N/ ROOM 115 A B C D E -2 HIGH B AY AREA ROOM 130 WETERS -6 F G H I FIGURE 4: Surveyed Portion of Building 400, Indicating the Floor Grid Established for Reference 12

i CEV4a t I ( 10 l l 8 ROOM 114 6 l 4 1 ';1,

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A B C D E f., MEASUREMENT ' t #' LOCATIONS N h 0 2 I I METERS FIGURE 5: Contamination Measurement Locations on the Floor and Lower Walls of Room 114 13

o GEV4d i l [ 2 ,, ',. '.l RobM,*1\\ S. l-l ll ll '* *l O F G MEASUREWENT 1/l' LOCATION 5 N n l.;.,.;.;..l 0 2 I I WETERS FIGURE 6: Contamination Measurement Locations on the Floor and Lower Wolls of Room 115 14

s GEV4b = WNDOWS = i _/\\ l 1 10 ? ROOM 129 ur 6 w-r 1 s 4 y F / C / 2 G h/ L /. l / p /M F L l / / I H l MEASUREMENT / I LOCATIONS / i / / N a 0

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0 2 l 1 l METERS FIGURE 7: Contamination Measurement Locations on the Floor and Lower Wolls of Room 129 a 15 m

GEV4c E ,+ 1 ...d ; y .l ~3 c. '3 ye 7, r. s j.' ~ i *; -{ :~. e !5-)k'-Nk 7 E1 w 0 Y M [ h HIGH BAY AREA ROOM 130 sr -4 g -6 F G H I "= p WEASUREWENT 1-LOCATIONS P N il O 2 1 I METERS A r FIGURE 8: Contamination Measurement Locations on the 7 Lower Walls of the High Bay Area (Room 130) p 16 = L

cEv49 a 10 7 8 O ROOM 114 6 ^ 4 l 0 4 2 a 0 i A B C D E A OUTER DUCT SURFACE A INNER DUCT SURFACE S UPPER WALL AND COUNG S UGHT F1XTURE OR BEAM N O ll 0 2 I I WETERS FIGURE 9: Measurement Locations on Upper Wells, Ceiling, and Overhead Surfaces of Room 114 17 I

CEV4tt 1 = 4 2 ROOM 115 0 F G A (NNER DUCT SURFACE 9 UPPER WALL AND COUNG S UCHT F1XTURE OR BEAM N h 0 2 I I METERS 2 FlGURE 10: Measurement Locations on Upper Walls, Ceiling, and Overhead Surfaces of Room 115 18 b

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? o ..- r, u. '..s' I ', '5 =. w f-{l ll 8 A ....fy.1 r ;G p h 6 ^ r ROOM 129 g: 2,y ;; ,. w., , r~. 3 s [ i i' m ~.'a., C 4 0 F y( ,'.'* I. l = / 2 f h/ Y / 9 1 l F / E .5 l JQ / r / H I l 6 OUTER DUCT SURFACE i / A INNER DUCT SURFACE [ j S UPPER WALL AND COUNG @ UGHT F1XTURE OR BEAM ~ d ~ 7 0 2 l 1 1 METERS FIGURE 11: Measurement Locations on Upper Walls, Celling, and Overhead Surfaces of Room 129 s E-19 u g i

cEv4e I si o 1 0 A -2 HICH BAY AREA e 1 -4 0 e e -6 F G H I e UPPER WALL AND COUNG e UCHT FIXTURE OR BEAM e, e N ll 0 2 1 1 METERS Measurement Locations on Upper Walls, Celling (Room 130) FIGURE 12: and Overhead Surfaces of the High Bay Area 20

cEv4 \\ l [_D CORRIDOR OFRCE 10 ' N ) 8 6 ROOM 11 4 RocM 129 4 4 e 2 ~ \\[ ROOM 115 AJ . MEASUREWENT A B C D E LOCATIONS -2 HIGH B AY AREA S -4 utTtas -6 F G H l FIGURE 13: Drain Line Contamination Measurement Locations 21 {

l GEV2O ( ( 'U' '03 102 1 101 103A 3 105 1-7 l 104 113 109 11 5 106A 117 ) 106 119 121 123 x 125 AA 11o /112 gegemegt ECulPMENT 127 l e ( sAMPUNG , LOCATIONS 129 11 4 N h 11 5 e 6 i HIGH BAY j 130 I FIGURE 14: Building 400 Paint Sampling Locations 22 L - -- -

GEV4h I k l ( \\ r_3 CORRIDOR 10 6 8 6 ROOM 11 4 ROOM 129 4 ROOM 115 QRE WO g I' FLOORING A B C D E I

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0 'l / /e / /// F G H I FIGURE 15: Indoor Soil Sampling Locations 23 l

GEV4l s i k r [ [ \\ r 3-7 CORRIDOR OFFICE 10 8 0 ROOM 11 4 M 4 9 l g/ ROOM 115 . mz A CONCRETE O M CHIPS A B C D E N -2 g H10H BAY AREA 0 2 -4 I I utters -6 F G H I FIGURE 16: Floor Tite end Concrete Sampling Locations { 24 ) Y

CEV1@ / TO 200 ROADWAY 300 % gggA A RE' A 9) [ EN g CE 4 5 Om m a "\\/ GATE se n: PARKING LOT D-TANK BUILDING LOCATION OF 400 at ELEVATED DIRECT RADIATION g, WECK c-W ~ 3g D ~ tt BAY I BUILDING gO e [ 401 g

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. :.tre. y3g\\\\\\\\ \\ h ':. ~:::- h SPILLWAY MEASUREMENT AND y I g SAMPLING LOCATIONS [ U EARmEN WALL { FENCE FIGURE 17: Locations of Exposure Rote Measurements and Soil Sampling 25 L

CEV5 4 4 DEd u i I 2 b ROOM 114 RM. 129 A l m h i N l-l Q R )i Q o ,~7 L Q C RM. 115 ll d5 6 l Q G ^ 1 Q Q l-Q Q g g J l Q n HICH BAY. AREA f g Q ll! A GRAVEL SAMPUNG LOCATIONS g g e SWEAR SAMPUNG LOCATIONS g Q. Q 2 y . 1 1 ,4= q % }l-8 {::: 0 =--QC 0 1 2 I l l ME TERS FIGURE 18: Outside Ventilation System Indicating Sampling Locations -r-g--4,-m-, ,, + ~ - - - =-=-,-w-y ,,-m- -.y

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GEV'3 i i i 8 0 -2 HIGH BAY AREA b O -6 F G H I O l T LOCATIONS OF O RESOUAL CONTAWINATION N l d i l i 0 2 i 1 WErtms .i FIGURE 19: Locations of Residual Contomination Identified by Surface Scans t ? 27 1 r _ _ _..._,_ _,,.,. _ ~ - -.., -. _ _ 7-

TABLE I SupeWlY OF SLEFACE 00NTAsllNATION BEASURDIENTS OF BUILDING 400 GENERAL ELECTRIC 00NPANY PLEASANTON, CALIFORNI A 2 2 TOTAL CONTABIIIeATION ($sn/100 cm ) ROIOVABLE CONTMe1 NATION ($sm/100 cm ) location

  • Number of Alpha Beta-Gesume AlsAa Beta-Gessie gemesurements Range of Range of Range of Range of Nessurements Nessurements steesurements serasurements Roos, 114 FIcors/tomer seiIs 13

<40-330 <360-850 <3-34 <6-18 Upper malls /cellings 3 <40 <360 <3-5 <6-12 Vents, flutures, equip. 7 <40 <360 <3-5 <6 vu CD Room 115 Floors /lomer mells 14 <40-58C <360 <3-5 <6-10 upper malls /cellings 5 <40 <360-610 <3 <6-10 vents, flutures, equip, 3 <40 <360 <3-5 <6 Roas 129 Floors / lower sells 12 <40- 95 <360-830 <3-7 <6-7 Upper walls /cellings 5 <40 <360-610 <3- $ <6 vents, flutures, equip. 5 <40-410 <360 <3 <6-8

l i1l ) 2 mc s e t 0 m t n s 0 s e e 1 e m / G e e an g r 9 p a n u 6 - 6 d t a s < 6 < ( e R e B s t N I O I T Ae s l eg A T s N f t O on C a e 9 5 h e m 3 - - E lp g e < 5 3 L n r B A a u A R s V e O s 0 N 9 ER S T 6D 00 0 E 63 7 D 57 5 R 8 U s t 00 0 S w f n 66 6 A ) 2 oe 33 3 E S Y m m N A c # e e ) N A I g r 0 a n u Fm d O 0 t a s e I 0 D u T 0 O 0 1 e R e i A 4 CF / B s n n 90 t lN 8 e G CL p n e N I A o p o A I R C ( C T DT d L C, N e ( N I E N O m O i I C U L O I o r B E T T E E N A t &LAS Ie r L C A e B A A F R A I p es T R E E A U NL T t S EP N s 00 0 o G O t 88 1 n W C n 32 5 f e s L om 00 0 t Y A a e 4 4 4 n R T h

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te rs T l e A e r pu R m u i s S t aem no t t s en f t i one m rm a ee t b r 30 4 n m u 1 o ms c 6 e 9 m t i c t er i d .d p 2 e l 1 v s u - o b g g S m sn e e s r l I a I e ei s r r me e u o r g o e r /c u e i l e r est F f n A wI a oer o o! l y l ef t t i o / s o ta B s rr e c r r s fh o l oet e e L ig op np e R l H f U V U

' 5-TABLE 2 i

SUMMARY

OF SURFACE CONTAMINATION HEASUREMENTS IN BUILDING 400 DRAIN LINES GENERAL ELECTRIC COMPANY PLEASANTON, CALIFORNIA Grid Removable Contaminationb Locationa Block Alpha (dpm/100 cm') Beta (dps/100 cm') Room 114 4.6 C+.2 <3 (6 Room 114 2,C+.2 7 10 Room 114 10.5,C+.1 3 <6 Koom 129 2.9,H+.3 <3 <6 aRefer to Figure 13. bDue to the small diameter of the drain openings, direct contamination measurements were not possible. 30 1

f. TABLE 3 RADIONUCLIDE CONCENTRATIONS IN SOIL SAMPLES COLLECTED INSIDE BUILDING 400 GENERAL ELECTRIC COMPANY PLEASANTON, CALIFORNIA Grid' Radionuelide Concentrations (pci/s) Locations Block U-238 U-235 Gd-153 Co-60 Cs-137 Room 114 2A <0.3 <0.2 <0.2 <0.1 (0.1 Room 114 10.6, A+1 <0.5 <0.2 <0.2' <0.1 <0.1 Room 114 1,D+1 <0.4 <0.2 <0.2 <0.1 <0.1 Room 114 & 129 5,E+1 <0.6 <0.2 <0.2 <0.1 <0.1 Room 129 1,I <0.3 <0.2 (0.2 <0.1 (0.1 High Bay -2,H+1 <0.6 <0.3 <0.2 <0.1 <0.1 Migh Bay -4,G+1.1 6.7 2 1.lb (o,3 <o,2 <o,1 <o,g High Bay -2,E+1.8 <0.5 <0.2 <0.2 <0.1 <0.1 Migh Bay -4,E+1.5 4.2 t 0.5, <0.2 <0.2 <0.1 <0.1 i High Bay -4.5,F+1.5 <0.2 <0.3 <0.2 <0.1 (0.1 aRefer to Figure 15. 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. a f s 6 1 a 31

TABLE 4 RESULTS OF ANALYSES OF PAINT SA!!PLES COLLECTED FR0tt BUILDING 400 GENERAL ELECTRIC COMPANY PLEASANTON, CALIFORNIA Radionuclide Concentration (pCi)b i Locationa Grid U-238 U 's5 Gd-153 Co-60 Cs-137 Block Room 114 0, C+1.5 4.0 t 6.0c <1.2 <0.2 <0.3 <0.3 Room 114 7.5, E+.4 17.8 2 22.2 3.6 2 3.0 <0.2 <1.9 <1.2 Room 115 0, E+.4 4.92 4.5 <1.6 <0.2 <0.3 <0.3 Room 129 3, C 17.5 t 13.7 <3.9 <0.2 <0.9 <0.7 Room 129

0. I+.8 8.7 2 7.7

<2.6 <0.2 <0.5 <0.6 High Bay Area 0, F 67.1 1 50.3 5.0 2 6.6 <0.2 <4.0 <3.3 South Wall of 15.5 t 21.3 <4.8 <0.2 <1.4 <1.3 Hallway West of entrance to rcom 129 aRefer to Figure 14 2 brotal activity collected from 100 em area. eUncertainties represent the 95% confidence levels, based only on counting statistics 1 additional laboratory uncertainties of 2 6 to 10% have not been propagated into these data. 32

T V TABLE 5

SUMMARY

OF RADIONUCLIDE CONCENTRATIONS IN FLOOR TILE AND CONCRETE SA!!PLES COLLECTED FROM BUILDING 400 CENERAL ELECTRIC COMPANY PLEASANTON, CALIFORNIA Grid Radionuclide Concentrations (pCi/g) Locationa Blogh U-238 U-235 Gd-153 co-60 Cs-137 Room 114 8,B <1.1 <0.5 <0.2 <0.2 <0.1 Floor Tile Room 114 2.D <2.9 <1.7 <0.2 <0.5 <0.5 Floor Tile Room 129 2.9,H+3 28.0 t 3.0b 2.6 t 1.2 <0.2 <0.2 0.3 + 0.3 . Drain Tile Room 129 0,I (2.7 <1.3 <0.2 <0.4 (0.4 Concrete Chips High Bay -6,F <3.3 <1.8 <0.2 <0.6 <0.4 Concrete Chips aRefer to Figure 16. bUncertainties represent the 95% confidence levels, based only on counting statistics; additional laboratory uncertainities of 2 6 to 10% have not been propagated into these data. 33

r I L t l I i TABLE 6 [ l EXPOSURE RATES OUTSIDE BUILDING 400 GENERAL ELECTRIC COMPANY PLEASANTON, CALITORNIA l i Exposure Rate (tR/h) Location".. At Surface Contact At la above Surface l 1 11 2 11 11 '3 11 10. 4 11 t 5 12 12 6 11 11 i JI aRefer to Figure 17. i l [ i j k i l t I r i l 6 l I r i I I F i t t

l I l iI 1l IIll 1 2 n o 00 1 /ep 4( e 7 8 N m TIO moC A N a l t ts e A s TN OC E L 3 B 2 A m V c O M 0 E 0 R 1 5 3 v ap d( a W h ( p l S A T S NM E E NT E S R Y US 2) SA N Y m MO NA c A l I N A )Fm T 0O B O L X 0 I I I ( F /m 0 0 T T I 7 A I CL p 6 6 NDI A d 3 3 E l V RC i e L s T B A E C, e T N ID E N m A T L O N m O S E T O o CT N C I U L A T EO AS A a C R A t B N t A 0 E E e F 0 e e L s R 4 DP A U C T S G N N O F I C OD L L ) A 2 Y I R U T m mB O c T e D 5 O L S I / 5 0 e 4 4 p o ( a h p l A m r m o e f t t 8 s a 1 oy l t s p er r r n u ee o g pt i el n F n ei a o Df f o l t t t e t a sd s r c ui u e o a s a f L b t h e m u n R E o E b* e l l

r TABLE 8 RADIONUCLIDE CONCENTRATIONS IN SOIL COLLECTED OUTSIDE BUILDING 400 GENERAL ELECTRIC C0!!PANY PLEASANTON, CALIr0RNIA Radionuclide Concentrations (pCi/g) Locationa U-238 U-235 Gd-153 Co-60 Cs-137 1 (0.4 <0.2 <0.2 <0.1 <0.1 2 <0.8 <0.2 <0.2 <0.1 0.lb 3 o,1 l l 3 <0.5 <0.3 <0.2 <0.1 0.4 20.2 l 4 <0.7 <0.3 <0.2 <0.1 0.7 20.2 I 5 (0.5 <0.3 <0.2 0.3 20.1 0.8 t 0.2 6 <0.8 <0.3 <0.2 <0.1 0.4 20.1 tiest of Building 400 North of Utility Shed <0.6 <0.3 (0.2 8.7

  • 0. 5

<0.1 aRefer to Figure 17 bUncertainties represent the 95% confidence level, based only on counting l statistics; additional laboratory uncertainties of f 6 to 10% have not been propagated into these data. I l 36 f

TABLE 9 RADIONUCLIDE CONCENTRATIONS IN SURFACE GRAVEL SAMPLES COLLECTED FROM THE ROOF OF BUILDING 400 CENERAL ELECTRIC COMPANY PLEASANTON, CALIFORNIA l Radionuclide Concentrati on (pCi/g) Locationa U-238 U-235 cd-153 Co-60 cs-137 1 High Bay <0.8 <0.5 <0.2 <0.2 0.8 20.3b Underneath Damper 2 Underneath Air <0.5 <0.3 <0.2 <0.1 0.3 2 0.2 i Exhaust Vent l l aRefer to Figure 18. j buncertainties represent the 95% confidence level, based only on counting statistics; additional laboratory uncertainties of f 6 to 10% have not been propagated into these data. { 37

REFERENCES 1. Letter from C.G. Cunningham (General Electric Co.) to R.R. Thomas L (U.S. Nuclear Regulatory Commission, Region V),

Reference:

"License SNM-960, Docket 70-754", June 16, 1987. .2. "Proposed Confirmatory Radiological Survey Plan for Valiecitos Nuclear Center, Building 400, General Electric Corporation, Pleasanton, California," Oak Ridge Associated Unviersities, July 31, 1987. t 38

l APPENDIX A MAJOR SAMPLING AND ANALYTICAL EQUIPMENI i (

3 APPENDIX A MAJOR SAMPLING AND ANALYTICAL EQUIPMENT The display or description of a specific product is not to be construed as an endorsement of that product or its manufacturer by the authors or their employer. A. Direct Radiation Measurements Eberline "RASCAL" \\ Portable Ratemeter-Scaler l Model PRS-1 (Eberline, Sante Fe, NM) Eberline PRM-6 Portable Ratemeter (Eberline, Sante Fe, NM) Ludlum Floor Monitor Model 239-1 (Ludlum, Sweetwater, TX) Eberline Alpha Scintillation Probe Model AC-3-7 (Eberline, Sante Fe, NM) Eberline GM Pancake Probe Model HP-260 (Eberline, Sante Fe, NM) Victoreen Beta-Gamma "Pancake" Detector Model 489-110 (Victoreen, Cleveland, OH) Victoreen NaI Scintillation Detector Model 489-55 (Victoteen, Cleveland, OH) Reuter-Stokes Pressurized Ionization Chamber Model RSS-111 (Reuter-Stokes, Cleveland, OH) B. Laboratory Analyses Automatic low-background Alpha-Beta Counter Model LB5110-2080 (Tennelec, Inc., Oak Ridge, TN) High-Purity Germanium Detector Model GMX-23195-S, 23% efficiency (EG&G ORTEC, Oak Ridge, TN) A-1

Used in conjunction with: Lead Shield, G-16 (Gamma Products Inc., Palos Hills, IL) High Purity Germanium Coaxial Well Detector Model GWL-110210-PWS-S, 23% Efficiency (EGGG ORTEC, Oak Ridge, TN) Used in conjunc. tion with: Lead Shield Mo..a1 G-16 (Applied Physical Technology, Atlanta, GA) High Perity Germanium Detector Model IGC25, 25% Efficiency (Princeton Gamma-Tech, Princeton, NJ) Used in conjunction with: Lead Shield (Nuclear Data, Schaumburg, IL) Multichannel Analyzer l ND-66/ND-680 System I (Nuclear Data Inc., Schaumburg, IL) l l ( \\ l A-2

i ) ) APPENDIX B MEASUREMENT AND ANALYTICAL PROCEDURES 1 ) i 1

APPENDIX B l ( Measurement and Analytical Procedures Surface Scans Surface scans in the facility were performed by passing the probes slowly over the surface. The distance between the probes and the surface was maintained at a minimum - nominally about I cm. Identification of elevated levels was based on increases in the audible signal from the recording or indicating instrument. Alpha and beta-gamma scans of large surface areas on the floor of the facility 2 were accomplished by use of a gas proportional floor monitor, with a 600 cm sensitive area. The instrument was slowly moved in a systematic pattern to cover 100% of the accessible area. Combinations of detectors and instrument for the scans were: Beta-Gamma - Pancake G-M probe with PRM-6 ratemeter. Beta-Gamma - Pancake G-M probe with PRS-1 scaler /ratemeter. Gamma - NaI scintillation detector (3.2 cm x 3.8 cm crystal) with PRM-6 ratemeter. Alpha - ZnS probe with PRS-1 scaler /ratemeter. Alpha / Beta - Gas proportional floor monitor with Ludlum Model 2220 secler/ratemeter. Alpha and Beta-gamma Surface Contamination Measurements Measurements of total alpha radiation level were performed using Eberline Model PRS-1 portable scaler /ratemeters with Model AC-3-7 alpha scintillation probes. Measurements of total beta-gamma radiation levels were performed using Eberline Model PRS-1 portable scaler /ratemeters with Model HP-260 thin-window 1 "pancake" G-M probes. Count rates (cpm) were converted to disintegration rates 2 (dps/100 cm ) by dividing the net rate by the 4 x ef ficiency and correcting for 2 the active area of the detector. Effective window areas were 59 cn for the ZnS 2 detectors and 15 cm for the G-M detectors. The background count rate for Z nS alpha probes averaged approximately 2 cpm; the average backgrouad count rate was approximately 40 cpm for the G-M detectors. B-1

l Removable Contamination Measurements Smear measurements were performed on numbered filter paper disks, 47 mm in diameter. Smears were placed in labeled envelopes with the location and other pertinent information recorded. A ZnS alpha scintillation counting system was used to evaluate individual smears at the site; smears were recounted on a low I background proportional counter at the Oak Ridge laboratory. Exoosure Rate Measurements l Measurements of gamma exposure rates were performed using an Eberline PRM-6 portable ratemeter with a Victoreen Model 489-55 gamma scintillation probe containing a 3. 2 cm x 3.8 cm NaI(TI) scintillation crystal. Count rates were i converted to exposure rates (pR/h) by cross-calibrating with a Reutur Stokes model RSS-Ill pressurized ionization chamber. Soil Sample Analysis Soil samples were dried, mixed, and a portion sealed in 0.5-liter Marinelli beaker. The quantity placed in each beaker was chosen to reproduce the calibrated counting geometry and ranged from 600 to 800 g of soil. Net soil weights were determined and the samples counted usinfi intrinsic germanium detectors coupled to a Nuclear Data Model ND-680 pulse height analyzer system. Background and Compton stripping, peak

search, peak identification, and concentration calculations were performed using the computer capabilities inherent in the analyzer system. Energy peaks used for determination of radionuclides of concern were:

U ';3 5 - 0.144 MeV U-238 - 0.094 MeV from Th-234 (secular equilibrium assumed) Gd-153 - 0.103 MeV Co 1.173 MeV Cs-137 - 0.662 MeV The spectra were also reviewed for the presence of other radionuclides. B-2

Analysis of Miscellaneous Samples 1 l l Samples of miscellaneous material (drain residues, tile, gravel, and 1 ) building material) were crushed, as necessary, and placed in various size l containers and geometries, for which the gamma spectrometer had been calibrated. Analysis was performed using the same procedure as described above for soil samples. Smaller samples were also a nalyz ed for U-238 content by neutron activation. Aliquots of samples were exposed to a Californium 252 source (approximately 30 mg) for 15 to 30 minutes. Solid state gamma detectors were then used to determine U-239 content and relate that value to the total sample U-238 concentration. Uncertainties and Detection Limits The uncertainties associated with the analytical data presented in the tables of this report, represent the 95% confidence levels for that data. 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 procedure. Because of variations in background levels and Compton contributions from other radionuclides in samples, the detection limits dif fer f rom sample to sample and instrument to ins t rume n t. Additional uncertainties of 2 6 to 10%, associated with sampling and laboratory procedures, have not been propagated 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' Radiological Site Assessment Program. With the exception of the measurements conducted with portable gamma ~ scintillation survey meters, instruments were calibrated with NBS-traceable B-3

standards. The calibration procedures for the portable gamma ins trume nt s are performed by comparison with an NBS calibrated pressurized ionization chamber. Quality control procedures on all instruments included daily background and check-source mea su rement s to confirm aquipment operation within acceptable statistical fluctuations. The ORAU laboratory participates in the EPA and EML Quality Assurance Programs. t } t t B-4 t_.

l l l APPENDIX C GUIDELINES FOR DECONTAMINATION OF FACILITIES AND EQUIPMENT PRIOR TO RELEASE FOR UNRESTRICTED USE OR TERMINATION OF LICENSES FOR BYPRODUCT, SOURCE l OR SPECIAL NUCLEAR MATERIAL I L )

f GUIDELINES FOR DECONTAMINATION OF FACILITIES AND EQUIPMENT PRIOR TO RELEASE FOR UNRESTRICTED USE OR TERMINATION OF LICENSES FOR BYPRODUCT, SOURCE OR SPECIAL NUCLEAR MATERIAL U.S. Nuclear Regulatory Cocunission Division of Fuel Cycle & Material Safety Washington, D.C. 20555 \\ July 1982 l )

The instructio7s in this guide, in conjunction with Table 1, specify 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 not apply to premises, equipment, or scrap containing induced radioactivity for which the radiological considerations pertinent to their use may be dif ferent. The release of such facilities or items from regulatory control is considered on case-by-case basis. l 1. The licensee shall make a reasonable effort to eliminate residual contamination. l 2. Radioactivity on equipment or surfaces shall not be covered by paint, I

plating, or other covering material unless contamination
levels, as determined by a survey and documented, are below the limits specified in t

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. Surf aces or premises, equipment, or scrap which are likely to be centaminated but are of such size, construction, or i 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 possession or control of premises, equipment, or scrap having surfaces contaminated with materials in excess of the limits specified. This may include, but would not be limited to, special circumstances such as razing of buildings, transfer of premises to another organization continuing work with radioactive materials, or conversion of facilities to a long-term storage or standby status. Such raquests must: a. Provide

detailed, specific information describing the
premises, eq uipment or scrap, radioactive contaminants, and the nature, extent, and degree of residual surface contamination.

b. Provide a detailed health and safety analysis which reflects that the residual amounts of materials on surface areas, together with other considerations such as prospective use of the premises, equipment or scrap, are unlikely to result in an unreasonable risk to the health and safety of the public. f 5. 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 the survey report shall } i C-1 f

be filed with the Division of Fuel Cycle and Material Safety, USNRC, Washington, D.C. 20555, and also the Administrator of the NRC Regional Office having jurisdiction. The report should be filed at least 30 days prior to the planned date of abandonment. They survey report shall: a. Identify the premises. b. Show that reasonable effort has been made to elietnate residual contamination. c. Describe the scope of the survey and general procedures followed. d. State the findings of the survey in units specified in the inst Nction. l Following review of the report, the NRC will consider visiting the tacilities to confirm the survey. l l l l 1 i t ( C-2 L____.___.__._____

TABLE I ACCEPTABLE SURFACE CONTAMINATION LEVELS Nuclidesa Averageb,c,f Maximumb,d,f Removableb.e.f 2 2 2 U-nat, U-235, U-238, and 5,000 dpm a/100 cm 15,000 dpm a/100 cm 1,000 dpm o/100 cm associated decay products 2 2 2 Transuranics, Ra-226, Ra-228, 100 dpm/100 cm 300 dpm/100 cm 20 dpm/100 cm Th-230, Th-228, Pa-231, Ac-227, I-125, I-129 2 2 2 Th-nat, Th-232, Sr-90, Ra-223 1,000 dpm/100 cm 3,000 dpm/100 cm 200 dpm/100 cm Ra-224, U-232, I-126, 1-131, I-133 2 2 2 Beta gamma emitters (nuclides 5,000 dpm By/100 cm 15,000 dpm By/100 cm 1,000 dpm SY/100 cm with decay modes other than 7 alpha emission or spontaneous fission) except Sr-90 and w others noted above. 1 a Where surface contamination by both alpha-and beta gamma-emitting nuclides exists, the limits established for alpha-and beta garma-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 l background, efficiency, and geometric factors associated with the instrumentation. Measurements 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 maximum contamination level applies to an area of not more than 100 cm, 2 e The amount of removable radioactive material per 100 cm of surface area should be determined by wiping that area with dry filter or sof t absorbent paper, applying moderate pressure, and assessina, the amount of radioactive 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. The average and maximum radiation levels associated with surface contamination resulting from beta-gamma f 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 milligrams per square centimeter of total absorber.

t i SOIL CONTAMINATION GUIDELINES The Nuclear Regulatory Commission has established guidelines for L radionuclide concentrations in soil at sites being released for unrestricted use. Guidelines for uranium are presented in the NRC's Branch Technical Position f on "Disposal or Onsite Storage of Thorium and Uranium Wastes. from Post Operations," published in the Federal Register on October 23, 1981. These / uranium values are: 35 pCi/g total uranium in depleted or natural isotopic abundances (without daughters in equilibrium) 30 pCi/g total uranium enriched in U-235 Guidelines for Cs-137 and Co-60 have been developed by the NRC for several sites, on an individual (site specific) basis. Concentration guidelines a re { typically in the following ranges: 15 to 17 pC1/g Cs-137 3 6 to 10 pCi/g Co-60 i i C-4 )}}

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