ML012270404

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Request to Release Certain Portions of General Atomics Facility to Unrestricted Use and Delete Them from Its License: Namely, the Linac Land Area
ML012270404
Person / Time
Site: 07000734
Issue date: 08/02/2001
From: Asmussen K
General Atomics
To: Adams M, Rogus R
NRC/NMSS/FCSS, State of CA, Dept of Health Services
References
-RFPFR, CAL/696-3395
Download: ML012270404 (60)
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GENERAL ATOMICS

  • 0 August 2, 2001 CAL/696-3395 VIA EXPRESS MAIL SERVICE ATTN: Dr. Ronald Rogus (in Duplicate)

State of California Department of Health Services Radiologic Health Branch Mail Stop 178 601 North 7th Street Sacramento, CA 95814-0208

Subject:

Radioactive Materials License No. 0145-37: Request to Release Certain Portions of General Atomics' Facility to Unrestricted Use and Delete them from its License: Namely, the LINAC Land Area and Ms. Mary Adams Licensing Section 1/Licensing Branch Division of Fuel Cycle Safety and Safeguards, NMSS U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Docket No.70-734; SNM-696: Request to Release Certain Portions of General Atomics' Facility to Unrestricted Use and Delete them from its License: Namely, the LINAC Land Area

Dear Dr. Rogus and Ms. Adams:

As you are aware, General Atomics (GA) is continuing its efforts to decontaminate, as appropriate, and obtain the release to unrestricted use of selected facilities and land areas on its site. GA has recently completed the Final Radiological Survey of the LINAC Land Area which is located on the northwestern portion of GA's Main Site.

The LINAC Land Area includes the land surrounding the Building 30/31 complex on the south, east and west, a concrete structure that previously housed a cooling system for LINAC, and a workshop used by Jackson and Blanc (J&B), a Heating and Air Conditioning contractor. It does not include the Building 30/31 complex, the LINAC North Land Area, or Building 25 and its surrounding land area. See enclosed Figures 1, 2 and 3. The total land area to be released to unrestricted use in the Linac Land Area is approximately 120,000 ft2 (-1.1,200 M2).

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R. Rogus and M. Adams August 2, 2001 CALU696-3395 Page 2 The enclosed report titled "General Atomics' Final Radiological Survey Report For The LINAC Land Area," dated August 2001, documents the results of the comprehensive radiological measurements and soil sampling and analysis completed on this land area.

The results of these surveys, measurements and analyses demonstrate that the LINAC Land Area meets the State and NRC approved criteria for release to unrestricted use. No decontamination was required.

Accordingly, GA hereby requests the State of California (State) and the U.S. Nuclear Regulatory Commission (NRC) to release the LINAC Land Area, as described in the enclosed report, to unrestricted use and delete it from GA's State and NRC radioactive and special nuclear material licenses, respectively. Consistent with discussions during the April 2001 NRC/State/GA coordination meeting, it is GA's understanding that the State is the lead regulatory agency for the LINAC Land Area.

If you should have any questions regarding this information, please contact Laura Q. Gonzales at (858) 455-2758, or me at (858) 455-2823. Your assistance in responding to our request is very much appreciated.

Very truly yours, Keith E. Asmussen, Ph.D., Director Licensing, Safety and Nuclear Compliance

Enclosures:

1) Figure 1:

Main Site and Sorrento Valley Site

2) Figure 2:

LINAC Land Area in Relationship to Surrounding Area

3) Figure 3:

LINAC Land Area Boundary

4) Report titled: "General Atomics' Final Radiological Survey Report for the LINAC Land Area," dated August 2001 cc: Mr. Wayne L. Britz, Fuel Cycle Inspector, NRC Region IV Ms. Kathleen Henner, State, Brea, CA Ms. Sudana Kwok, State, Sacramento, CA Dr. D. Blair Spitzberg, Chief, NMSS Branch 3, NRC Region IV

GENERAL ATOMICS' FINAL RADIOLOGICAL SURVEY REPORT for the LINAC Land Area Prepared By: William LaBonte, Phil Poole and Laura Gonzales Illustrated By: Stephen Finchum Final Survey Technicians: Phil Poole, Scott Cowan, Cornelius Stanley, and Jeff Vassett Confirmatory Survey Technician: Richard Stowell August 2001

Table of Contents IN TRO DU CTIO N................................................................

I SITE DESCRIPTION.............................................................

I PREVIOUS ACTIVITIES (HISTORY OF USE) & CLASSIFICATION.....................

I H istory...................................................................

1 C lassification..............................................................

2 CRITERIA FOR RELEASE TO UNRESTRICTED USE.................................

2 Facilities and Equipment (and Asphalt or Concrete Surfaces)........................

2 Release Criteria for Soils.....................................................

2 Exposure Rate Guideline.....................................................

3 INSTRUMENTATION & BACKGROUND MEASUREMENTS...........................

3 Background Measurements for Instruments/Detectors 3

Background Soil Concentrations of Concern.....................................

4 Exposure Rate Background...................................................

4 FINAL SURVEYS PERFORMED...................................................

4 Objectives and Responsibilities...............................................

4 Survey Plans..............................................................

4 Soil Sam pling.............................................................

5 SURVEY SUM M ARY.........................................................

5 COMPARISONS OF SITE DECOMMISSIONING PLAN REQUIREMENTS WITH SURVEYS PERFORM ED................................................

6 RESULTS OF THE FINAL SURVEYS............................................

7 Scan R esults............................................................

7 Fixed Alpha M easurements 7

Fixed Beta M easurem ents.................................................

7 Rem ovable A ctivity 8

Exposure Rate Surface Scans..............................................

8 Fixed Exposure Rate Measurements.........................................

8 Storm Drain Exposure Rate Surveys 9

Soil and Drain Samples (18) and Results.....................................

9 Exposure Rate Measurements at Soil Sampling Locations 10 CONFIRMATORY SURVEYS.................................................

10 CO N CLU SION..............................................................

10 List of Tables Table 1:

USNRC's Acceptable Surface Contamination Levels.........................

T-1 Table 2:

State of California's Acceptable Surface Contamination Levels.................

T-2 ii

Table 3:

Table 4:

Table 5:

Table 6:

Figure 1:

Figure 2:

Figure 3:

Figure 4:

Figure 5:

Figure 6:

Figure 7:

Figure 8:

Figure 9:

Figure 10:

Figure 11:

Figure 12:

Figure 13:

Figure 15:

Figure 16:

Figure 17:

LINAC Land Area List of Instruments....................................

T-3 Background Soil Sample Results.........................................

T-6 LINAC Land Area Swipe Survey Results..................................

T-7 LINAC Land Area Soil Sample Results...................................

T-10 List of Figures (unpaved)

Torrey Pines (Main) Site Land Areas LINAC Land Area LINAC Land Area Classification LINAC Land Locations and Results of Alpha Scan Measurements LINAC Land Locations and Results of Beta Scan Measurements LINAC Land Locations and Results of Fixed Alpha Measurements LINAC Land Locations and Results of Fixed Beta Measurements LINAC Land Locations and Results of Exposure Rate Surface Scans LINAC Land Locations and Results of Exposure Rate Measurements at 1 Meter LINAC Land Locations of Removable Contamination Surveys LINAC Land Soil Sample Locations and Exposure Rate Measurements at Soil Sample Locations LINAC Land J&B Work Shop, Locations and Results of Alpha and Beta Scan LINAC Land J&B Work Shop, Locations and Results of Fixed Alpha Measurements, Locations and Results of Fixed Beta Measurements LINAC Land J&B Work Shop, Locations and Results of Removable Contamination Survey LINAC Land J&B Work Shop Locations and Results of Exposure Rate Measurements LINAC Land, Locations and Results of Fixed Beta Measurements and Beta Scans.

Concrete Pad Outside of Building 30, Room 118 Appendixes Appendix A: Final Survey Plans for the LINAC Land Area Appendix B: LINAC Land Area Confirmatory Survey Plan and Results iii

+ GENERAL ATOMICS Final Radiological Survey Report For the LINAC Land Area Introduction General Atomics (GA) is continuing its efforts directed at decontaminating, as appropriate, and obtaining the release to unrestricted use of selected facilities and land areas at General Atomics.

GA has recently completed the Final Radiological Survey of the LINAC Land Area located on GA's Main Site. The total land area to be released to unrestricted use in the Linac Land Area is approximately 120,000 ft2 (-11,200 M2).

GA is requesting both the Nuclear Regulatory Commission (NRC) and the State of California (DOHS/RHB) to release this parcel of land to unrestricted use.

This report documents the results of GA's radiological measurements and soil sampling and analysis completed on the LINAC Land Area. The results of these surveys and analyses demonstrate that this land area meets the NRC and State approved criteria for release to unrestricted use.

Site Description The LINAC Land Area is located on GA's Main site as shown in Figure 1. The location of the LINAC Land Area in relation to other facilities at GA's Main Site and a diagram of the open LINAC Land Area to be released to unrestricted use are shown in Figures 2 and 3.

The LINAC Land Area includes the land surrounding the Building 30/31 complex on the south, east and west, a concrete structure that previously housed a cooling system for LINAC, and a workshop used by Jackson and Blanc (J&B), a Heating and Air Conditioning contractor. It does not include: 1) the Building 30/31 complex, 2) the LINAC North Land Area, or 3) Building 25 and its surrounding land area. The total land area to be released to unrestricted use in the Linac Land Area is approximately 120,000 ft2 (-11,200 m2). This report does not include sewer systems. These will be addressed in a future report.

Previous Activities (History of Use) & Classification History In 1998, a contaminated piece of ventilation system housing (a plenum) was discovered in a fenced in portion of a parking lot south of the Building 30/31 complex during a routine survey.

This portion of the parking lot had been, and continues to be, a storage area for miscellaneous material. The plenum was removed and disposed of as radioactive waste. A detailed survey was performed at that time of all equipment stored in this storage area and no other contaminated I

+ GENERAL ATOMICS Final Radiological Survey Report For the LINAC Land Area equipment was found. The remainder of the LINAC Land Area has no known history of use involving radioactive materials.

Classification The fenced in portion of the parking lot south of the Building 30/31 complex where the contaminated ventilation housing was discovered was classified as a Non-Suspect Affected Area for survey purposes. The remaining open land area was classified as a Non-Impacted Area. See Figure 3.

Criteria for Release to Unrestricted Use The primary radionuclides found at GA facilities near the LINAC Land Area, on occasion, are enriched uranium, depleted uranium and mixed fission and activation products (mainly Cs-137 and Co-60).

Facilities and Equipment (and Asphalt or Concrete Surfaces)

The U.S. NRC's and the State of California's approved criteria for releasing facilities and equipment to unrestricted use are shown in Tables 1 and 2, respectively. The applicable guidelines for enriched uranium (and beta/gamma emmitters including Cs-137 and Co-60) are as follows:

5,000 dpm/100 cm 2, averaged over a 1 m2 area 15,000 dpm/100 cm 2, maximum in a 100 cm 2 area if the average over 1 m2 is met 1,000 dpm/100 cm2, removable activity Release Criteria for Soils The predominant radionuclides found in the soil at GA facilities near the LINAC Land Area and the approved release criteria in pCi/g (above natural background concentrations) for these radionuclides are provided as follows:

Enriched Uranium (U-234 + U-235) 30 pCi/g Depleted Uranium 35 pCi/g Cs-137 15 pCi/g Co-60 8 pCi/g If more than one radionuclide exists, the sum of the fractions of the concentrations is calculated as follows:

i c=<1

=1Li 2

r

+

GENERAL ATOMICS Final Radiological Survey Report For the LINAC Land Area Where:

Ci = The average concentration levels of radionuclide i in the sample (above background).

Li =

The release criteria for radionuclide i.

The sum of the fractions must be less than or equal to one (1).

Exposure Rate Guideline Exposure rates measured at 1 m above the surface are not to exceed 10 pR/hr above natural background levels.

Instrumentation and Background Measurements A list of instruments used during the radiological surveys is shown in Table 3. The table includes: (1) a description of the instrument, model number and its serial number, (2) a description of the detector (if applicable) and its serial number, (3) instrument ranges, (4) calibration due dates, (5) typical background readings and (6) calibration efficiencies (if applicable). All of the instruments used were calibrated semiannually and after repair, except for exposure rate meters which were calibrated quarterly.

Background Measurements for Instruments/Detectors Building 13 on GA's main site was used for conducting background measurements with instruments used for the final survey because: (1) there is no history involving radioactive materials or storage of radioactive materials in Building 13, and (2) the various surfaces and construction materials found at the LINAC Land Area could also be found within and outside of Building 13. Background information, where appropriate, is included in Table 3.

Minimum detectable activities (MDA's) for instruments used for fixed measurements, for each type of surface (see Table 3), were calculated using equation (5-2) from the NUREG/CR-5849 as shown below:

2.71 +4.65 B0*Rt Equation (5-2)

AMA 27 1 +

6OOCr

2)

A txEx Where:

100 BR =background rate (cpm) t = count time (min)

E = efficiency A = area of the detector (cm 2) 3

+

GENERAL ATOMICS Final Radiological Survey Report For the LINAC Land Area Background Soil Concentrations of Concern Typical background concentrations measured by gamma spectroscopy in soil near the GA site have been established (at the 95% confidence level) and are provided in Table 4 along with the locations where these samples were taken.

Exposure Rate Background Typical exposure rate background for GA's site using a Ludlum Model 19 micro R meter is 12-18 pR/hr measured at 1 m from the surface of soil. This range of exposure rates can be measured south of Building 15 (an office building on the eastern portion of the GA site).

Measurements taken offsite in 10 different locations (9 offsite and 1 onsite at a non-impacted area near Building 15) over a period of 15 months also averaged - 15 pR/hr (measured at 1 m from the surface). The range of 12-18 pR/hr is typical at the GA site for the external dose rates measured at 1 meter from the surface. Background measurements @ 1 m above an asphalt suface are generally higher due to the higher concentrations of naturally occurring radioactive material (NORM). This background fluctuates depending upon the asphalt batch used and the date applied. This background, (measured at 1 m from the surface) ranges from 22-30 pR/hr.

Final Surveys Performed Objectives and Responsibilities The objectives of the final survey plans were: (1) to demonstrate that the average surface contamination levels for each survey unit were below the approved release criteria, (2) to show that the maximum residual activity did not exceed three times the approved release criteria for average surface contamination value in an area up to 100 cm 2, (3) to demonstrate soil sample results at the surface were well below GA's approved release criteria for unrestricted use, and, (2) that the exposure rate measurements taken in these areas, measured at 1 meter above the surface, were less than 10 pR/hr above background.

Survey Plans Final Survey Plans were developed based on the previous history of the adjacent Buildings, the LINAC Land Area site, the radionuclides of concern for this area, the potential for contamination, the various types of surfaces encountered and the classification of the various areas. See Appendix A for Final Survey Plans for the LINAC Land Area.

Surveys were taken in accordance with an approved survey plan(s) by qualified Health Physics Technicians having a minimum of three years health physics experience. Soil samples were counted in GA's Health Physics Laboratory which maintains an effective QA program.

4

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GENERAL ATOMICS Final Radiological Survey Report For the LINAC Land Area Every survey taken was documented on a daily basis to a worksheet/drawing showing the approximate locations surveyed/sampled. The documentation included the results of the measurements (including units), the technician's signature, date, instrument(s) used (including the model and serial number of both the ratemeter and detector), calibration due date, %

efficiency, background readings (if applicable) and any other pertinent information.

Soil Sampling Soil samples were collected in approximate locations as indicated on Figure 11. Each soil sample collected was properly logged, sealed, labeled, packaged and tracked.

Each of the soil samples taken was approximately 1 kilogram in mass. The samples were properly logged, labeled, tracked and packaged into plastic bags. All debris (i.e., grass, rocks, sticks, asphalt and foreign objects) was removed from each sample. Each soil sample was individually crushed to reduce large lumps, dried, placed into tared marinelli beakers (filled to the top), weighed, sealed and transported to GA's Health Physics Laboratory.

Soil samples were analyzed in GA's Health Physics Laboratory with a Canberra Low Sensitivity Gamma Spectroscopy MCA System using a high purity germanium detector. The system is calibrated using NIST traceable standards and performance checked daily. Soil samples were counted for a minimum of 30 minutes each. A 30 minute count was sufficient to detect the radionuclides of concern at levels below GA's approved soil release criteria.

Survey Summary Comparisons of the Site Decommissioning Plan requirements with the Final Surveys performed in relation to the percentage of surface area scanned, number of measurements (i.e., number of fixed radiation measurements), exposure rate measurements (VR/hr) and soil samples taken are provided as follows:

5

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GENERAL AromIcs Final Radiological Survey Report For the LINAC Land Area D-Plan = GA Site Decommissioning Plan The total surface area to be released is approximately 11,200 in2. The Non-Impacted area is approximately 10,390 in2, the Non-Suspect Affected area is approximately 810 M 2.

6 Comparisons of Site Decommissioning Plan Requirements with Final Surveys Performed Survey Area**

Gridding

  1. of Direct
  1. of Exposure Rate Surface Scans on
  1. of Soil Required Measurements Measurements asphalt or Samples

?

Fixed aX, P3, or (pR/hr) concrete Collected and Wipes on Analyzed concrete or asphalt D-Plan*

No Not Required Not Required Not Required Not Required Non-Impacted Area Final Surveys No Fixed (X= 75, 1000 readings at 1 25% of Flat 13 Surface (0 Non-Impacted Fixed P = 64 meter (every 3 Surfaces, 10% of 6") samples, 6 of Area Wipes = 75 meters), plus 1 Slopes.

these were taken measurement at I in storm drains.

meter from each soil sample location.

D-Plan*

No 1 per 50 m2or I per 10 m2 or 1 per 10% of Surface Not Required Non-Suspect 1 every - 7 m.

- 3 m Areas (asphalt Affected Area Total ; 81 and concrete)

Final Surveys No Fixed a =80, 1 per - 2 m 100% of 5 surface (0-6")

Non-Suspect Fixed P3

=80, Total=] 12 readings accessible samples, beneath Affected Areas Wipes=80 plus 1 measurement concrete and the asphalt at 1 meter from each asphalt surfaces pavement.

soil sample location and 100% scan

+

GENERAL ATOMICS Final Radiological Survey Report For the LINAC Land Area Results of the Final Surveys The results for the LINAC Land Area Final Surveys are provided in figures and tables as noted below:

Scan Results 100% of the surface in the Non-Suspect Affected Area was scanned for (X and P3 activity with large area (434 cm2) gas flow proportional detectors held within approximately 1" of the asphalt/concrete surface, and 10% of the surface area in the Non-impacted Area was similarly scanned.

The highest alpha activity scan result in the Non-Suspect Affected Area was 44 counts/minute (cpm) and the highest alpha activity measured in the Non-Impacted Area was 51 cpm (see Figure 4 for the general area scan and Figure 12 for the scan of the J&B workshop).

The highest beta scan result in the Non-Suspect Area was 2200 counts/minute beta and the highest beta scan result in the Non-Impacted Area (with the exception of the concrete pad outside of Room 118 of Building 30) was 3500 counts/minute (see Figure 5 for the general area and Figure 12 for the scan of the J&B workshop). Areas with beta activity above the established alert levels (see Survey Plan in Appendix A) were checked using a 100 cm 2 beta detector. All fixed measurements in these areas were below 700 dpm/100 cm2 and well below the release criteria of 1,000 dpm/100 cm2 (release limit of potential radionuclides). See Fixed Measurements below.

Beta scan results for the concrete pad outside of Room 118 of Building 30 ranged from 3000 3300 cpm (below alert levels).

Fixed Alpha Measurements A total of 80 1-minute fixed cc measurements were taken in the Non-Suspect Affected Area and a total of 75 1-minute fixed a measurements were taken in the Non-Impacted Area.

All alpha fixed measurements measured in the Non-Suspect Affected Area were below the MDA (218 dpm/100 cm2). All alpha measurements in the Non-Impacted area were also <MDA (218 dpm/100 cm 2). See Figures 6 and 13 (J&B workshop).

Fixed Beta Measurements A total of 80 2-minute fixed P3 measurements were taken in the Non-Suspect Affected Area and a total of 64 2-minute fixed P3 measurements were taken on the Non-Impacted Area.

7

+GENERAL ATOMICS Final Radiological Survey Report For the LINAC Land Area All beta fixed measurements in the Non-Suspect Affected area were <358 dpm/100 cm2 (MDA). The highest beta fixed in the Non-Impacted Area was 1544 dpm/100 cm 2 on a concrete pad which used to have ventilation equipment for Building 30. The area was also checked with a geiger counter; no elevated readings were noted. All fixed measurements were below the release criteria for uranium and beta/gamma emitters, which is 5,000 dpm/100 cm 2. Beta fixed measurements are provided in Figures 7 and 14 (J&B workshop).

Fixed measurement results for the concrete pad outside of Room 118 of Building 30 ranged from

<313 to 710 dpm/100 cm 2 (see Figure 17). Again, all measurements were below the applicable release criteria.

Removable Activity Eighty (80) wipe samples were taken in the Non-Suspect Affected Area and 75 were taken in the Non-Impacted Area. All samples were analyzed for aX and P3 activity. The highest a activity measured was <10 dpm/100 cm 2 and the highest P3 activity measured was 24 dpm/100 cm 2.

These results are far below the approved release criteria. See Figures 10 and 15 for locations and Table 5 for results.

Exposure Rate Surface Scans 100% of the Non-Suspect Affected Area was scanned with a NaI(T1) detector held approximately 1" from the surface. The exposure rate ranged from 12 to 18 [,R/hr. See Figure 8 for locations and results.

Approximately 25% of the flat open land areas in the Non-Impacted Area and -10% of the hillsides and slopes within this Non-Impacted Area were scanned with a Nal(T1) detector held within approximately 1" of the surface. The exposure rate results, as shown in Figure 8, ranged from 11 to 27 p.R/hr depending on the type of surface and the proximity to concrete sources.

The highest values, which were between 25-27 [LR/hr were measured on the asphalt or concrete surfaces next to concrete structures and were not due to radioactive contamination.

A concrete pad outside of Room 118 of Building 30 read between 25-27 p.R/hr, as shown in Figure 8, due to the high density concrete of the building. To verify that the readings were not to radioactive contamination, a total of 17 fixed measurements were taken on the concrete pad as shown in Figure 17. The highest fixed P3 measurements in this area was 710 dpm/100 cm2.

Fixed Exposure Rate Measurements A total of 112 fixed measurements were taken at im from the surface in the Non-Suspect Affected Area and a total of 1000 readings were taken in the Non-Impacted Area. The highest 8

+

GENERAL ATOMICS Final Radiological Survey Report For the LINAC Land Area exposure rate measured in the Non-Suspect area was 15 jiR/hr at 1 m and the highest exposure rate measurement in the Non-Impacted Area was 22.LR/hr at 1 m. These results are below the approved release criteria of 10 [.R/hr above background at 1 m (which would be -25 p.R/hr at 1 m). See Figures 9 and 16 for locations and results.

Storm Drain Exposure Rate Surveys Exposure rate measurements were collected on the surface of the eleven (11) storm drains. In some cases, measurements inside the openings were obtained. The maximum exposure rate measurement on the surface was 26 p.R/hr as shown on Figure 8.

Soil and Drain Samples (18) and Results A total of 12 surface soil samples were collected, processed and analyzed by gamma spectroscopy. Five (5) surface samples (0-6") were collected under the asphalt in the Non Suspect Affected Area. Seven (7) soil surface samples (0-6") were collected in the Non Impacted Area. The locations are shown in Figure 11 and the results are shown on Table 6.

In addition, six (6) samples of debris were collected from inside six of the storm drains in the Non-Impacted Area, as shown in Figure 11. The results are provided in Table 6. The other four two (2) storm drains did not have anything to collect and two (2) were inaccessible. A summary of the results is provided below.

Radionuclide Concentration (pCi/g) 238u 235u 137Cs 228Th 232Th 60Co High 3.04 0.24 0.33 1.99 2.77 0.06 Low 0.89 ND ND 0.59 1.10 ND Typical 2.26 0.18 0.09 1.28 1.72 ND

Background

I I

I I

Notes: 1.

ND means not detected as follows: <0.1 pCi/g Cs-137, <0.1 pCi/g Co-60,

<3.0 pCi/g U-238, <0.3 pCi/g U-235.

2.

The high concentrations for each isotope did not occur in the same sample. No sample had a sum of fractions greater than 1.0.

Thorium contamination was not present (as determined by process knowledge and gamma spectroscopy analyses of soil samples). All thorium results were at, or near, background levels and well below the release limit of 10 pCi/g.

9

+GENERAL ATOMICS Final Radiological Survey Report For the LINAC Land Area Uranium (U-238 and U-235) was at, or near, nominal background levels and well below the approved release limits.

Cs-137 was detected in 10 out of 18 soil samples. The highest activity level was 0.33 pCi/g, which is far below the approved release limit of 15 pCi/g.

Co-60 was detected in one (1) soil sample at 0.06 pCi/g which is far below the approved GA release limit of 8 pCi/g.

Exposure Rate Measurements at Soil Sampling Locations:

Exposure rate measurements (taken at 1 m from the surface) were also taken at each location where a systematic soil sample was collected. The highest result was 16 1LR/hr. See Figure 11 for soil sample locations and Table 6 for soil sample and exposure rate measurement results.

Confirmatory Survey Following the completion of the Final Survey, a Confirmatory Survey was performed, by a GA HP technician, who was not associated with the Final Survey. The internal Confirmatory Survey was conducted in accordance with an approved survey plan (see Appendix B). This survey consisted of three (3) equally spaced exposure rate measurements in the Non-Suspect Affected Area with a NaI(Tl) detector held approximately 1 meter from the surface and a slow walking pace scan of the Non-impacted area with a NaI(TI) detector held approximately one (1) meter from the surface.

All measurements were below the approved release criteria of 10 [.R/hr above background an in agreement with the final survey results. See Appendix B for details.

Conclusion Final contamination and radiation surveys, as well as the results of analyses of soil samples, as documented in this report, demonstrate that the LINAC Land Area meets the approved criteria for release to unrestricted use.

10

Table 1: USNRC'S ACCEPTABLE SURFACE CONTAMINATION LEVELS I Nuclides Averageb",

Maximumbfd,r Removableb",f I

(dpmI100cm2)

(dpm/100 cm2 )

(dpm/100cm2 )

U-nat, 235U, 238U, & associated decay products 5,000 CC 15,000 X 1,000 a Transuranics, 126Ra, 228Ra, 23 0Th, 228Th, 23 1Pa, 100 300 20 22 7Ac, 1251, 1291 Th-nat, 232Th, 9°Sr, 223Ra, 224Ra, 2 32 U, 1261, 1331, 1,000 3,000 200 1311 Beta/gamma emitters (nuclides with decay modes other than alpha emission or 5,000 15,000 1,000 spontaneous fission) except 9°Sr and other noted above.

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, an geometric factors associated with the instrumentation.

c Measurements 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.

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

f The average and maximum radiation levels associated with surface contamination resulting from beta-gamma emitters should not exceed 0.2 mRad/hr at 1 cm 2 and 1.0 mRad/hr at 1 cm 2, respectively, measured through not more than 7 milligrams per square centimeter of total absorber.

T-1

Table 2: STATE OF CA ACCEPTABLE SURFACE CONTAMINATION LEVELS Nuclides' Average',$

Maximum"$

Removableb"s I

(dpm/100ncm 2)

(dpm/loocm2)

(dpm/100cm2)

U-nat, 235U, 238U, & associated decay 5,000 15,000 1,000 products Transuranics, 226Ra, 228Ra, 231I'h, 228Th, 100 300 20 23 1pa, 227Ac, 1251, 1291 Th-nat, 232Th, 9°Sr, 223Ra, 224Ra, 232U, 1261, 1,000 3,000 200 133I, 1311 Betalgamma emitters (nuclides with decay modes other than alpha emission or 5,000 15,000 1,000 spontaneous fission) except 9`Sr and other noted above 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, an geometric factors associated with the instrumentation.

c Measurements of average contaminant should not be averaged over more than I square meter. For objects of less surface area, the average should be derived for each such object.

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 cm2 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 material on the wipe with an appropriate instrument of known efficiency. When removable contamination on objects of less surface area is determined, then pertinent levels should be reduced proportionally and the entire surface should be wiped.

f The average and maximum radiation levels associated with surface contamination resulting from beta gamma emitters should not exceed 0.2 mrad/hr at 1 cm 2 and 1.0 mrad/hr at 1 cm 2-, respectively, measured through not more than 7 milligrams per square centimeter of total absorber.

Guidelines For Decontamination of Facilities and Equipment Prior to Release for Unrestricted Use or Termination of Licenses For byproduct, Source, or Special Nuclear Material, also known as "Decon-I" incorporated into GA's State of CA Radioactive Materials License.

T-2

TABLE 3: LIST OF INSTRUMENTS Instrument Detector Range Calibration Due Efficiency

Background

Description (cpm, I1R/hr or mR/hr)

Date MDA (100 cm2 detector only or 50 cm2 detector)

Ludlum Ludlum Model 43-37 gas Four Linear Ranges 07-23-01 24.25%

0 - 20 cpm (concrete)

Active Probe Area = 434 cm2. The Model 2221 (434 cm2) proportional 0-500,000 & one 0 - 20 cpm (asphalt) detector and rate meter are combined and S/N 97287 Alpha detector Log 50-500,000 mounted on a roll around cart. The S/N 148926 (CPM) instrument features a static-flow system, quick connects, a portable gas bottle and a means to adjust the height of the detector from the floor for optimum performance.

Ludlum Ludlum Model 43-37 gas Four Linear Ranges 10-25-01 21.29%

3 - 21 cpm (concrete)

Active Probe Area = 434 cma2. The Model 2221 (434 cm2) proportional 0-500,000 & one Log 09-24-01 21.29%

2 - 19 cpm (asphalt) detector and rate meter are combined and S/N 84510 Alpha detector 50-500,000 mounted on a roll around cart. The S/N 093601 (CPM) instrument features a static-flow system, quick connects, a portable gas bottle and a means to adjust the height of the detector from the floor for optimum performance.

Ludlum Ludlum Model 43-37 gas Four Linear Ranges 09-03-01 22.15%

1858-2036 cpm (concrete)

Active Probe Area = 434 cm 2. The Model 2221 (434 cm 2) proportional 0-500,000 & one Log 07-14-99 21.26%

2400-2900 cpm (asphalt) detector and rate meter are combined and S/N 84459 Beta detector 50-500,000 a portion of linac mounted on a roll around cart. The S/N 086215 (CPM) land was surveyed in instrument features a static-flow system, 1999 quick connects, a portable gas bottle and a means to adjust the height of the detector from the floor for optimum performance.

Ludlum Ludlum Model 43-37 gas Four Linear Ranges 07-04-01 22.64%

1600-1995 cpm (concrete)

Active Probe Area = 434 cr1 2. The Model 2221 (434 cm 2) proportional 0-500,000 & one Log 2175-2460 cpm (asphalt) detector and rate meter are combined and S/N 154202 Beta detector 50-500,000 mounted on a roll around cart. The S/N 149017 (CPM) instrument features a static-flow system, quick connects, a portable gas bottle and a means to adjust the height of the detector from the floor for optimum performance.

Ludlum Ludlum Model 43-68 Four Linear Ranges 06-06-01 27.1 I 1%

933 +/- 19 cp2m (concrete) 100 cmi2 gas flow proportional counter.

Model 2221 100 cer2 proportional 0-500,000 & one Log MDA = 268 dpmr/100cm 2 S/N 148436 Beta detector 50-500,000 S/N 120477 (CPM) 1227 + 21 cp2m (asphalt)

I__

_MDA

= 315 dpmn/100cmn2 T-3

TABLE 3: LIST OF INSTRUMENTS (continued)

Instrument Detector Range Calibration Due Efficiency

Background

Description (cpm, pR/hr or mR/hr)

Date MDA (100 cm 2 detector only or 50 cm12 detector)

Ludlum Ludlum Model 43-68 Four Linear Ranges 09-26-01 24.13%

1042+90 cp2m (concrete) 100 cm 2 gas flow proportional counter Model 2221 100 cm 2 proportional 0-500,000 & one Log MDA = 313 dpm/100cm2 S/N 84423 Beta detector 50-500,000 S/N 119444 (CPM) 1371 + 55 cp2m (asphalt)

MDA = 358 dpmn/100cm 2 Ludlum RCA 6199 coupled to a Five Ranges 07-12-01 N/A 10-18 pR/hr I inch x I inch Nal (TI) scintillator is Model 19 Nal (TI) Scintillator 0-5 mR/hr mounted internally. Used for measuring Micro-R external dose rates on the surface and at Meter one meter.

S/N 144068 Ludlurn RCA 6199 coupled to a Five Ranges 07-04-01 N/A 10-18 pR/hr I inch x I inch Nal (TI) scintillator is Model 19 Nal (TI) Scintillator 0-5 mR/hr 04-09-01 mounted internally. Used for measuring Micro-R external dose rates on the surface and at Meter one meter SIN 87120 Ludlum RCA 6199 coupled to a Five Ranges 07-04-01 NA 10-18 [,R/hr 1 inch x 1 inch Nal (TI) scintillator is Model 19 Nal (TI) Scintillator 0-5 mr/hr 04-09-01 mounted internally. Used for measuring Micro-R external dose rates on the surface and at Meter one meter.

S/N 123930 Ludlum Ludlum Model 44-10 Four Ranges 07-04-01 NA 16-20 pR/hr (concrete-contact) 2 inch x 2 inch Nal (TI) scintillator. Used Model 3 Nal (TI) Scintillator 0-500 4R/hr 04-04-01 14-17 pR/hr (concrete-I meter) for measuring external dose rates on the S/N 153551 Gamma Detector 17-20 pR/hr (asphalt - contact) surface and at one meter.

S/N 155109 17-19 pR/hr (asphalt -I meter) 11-13 pR/hr (soil - contact) 11-13 l.tR/hr (soil - I meter)

Ludlum Ludlum Model 44-10 Four Ranges 06-07-01 NA 16-19 pR/hr (concrete-contact) 2 inch x 2 inch Nal (TI) scintillator. Used Model 3 NaI (TI) Scintillator 0-500 piR/hr 15-18 [-R/hr (concrete-I meter) for for measuring external dose rates on S/N 153590 Gamma Detector 19-21 tR/hr (asphalt -contact) the surface and at one meter.

S/N 155190 18-20 pIR/hr (asphalt -I meter) 11-13 pR/hr (soil - contact) 11-13 [IR/hr (soil - I meter)

T-4

TABLE 3: LIST OF INSTRUMENTS (continued)

Instrument Detector Range Calibration Due Efficiency

Background

Description (cpm, [,R/hr or mR/hr)

Date MDA (100 cm2 detector only or 50 cm 2 detector)

Ludlum Ludlum Model 44-62 Four Ranges 06-04-01 NA 7 - 9 lR/hr (concrete encased 0.5 inch x 0.5 inch Nal (TI) scintillator.

Model 3 Nal (TI) Scintillator 0-2500 l.IR/hr steel pipe)

Used for measuring internal dose rates of S/N 131601 Gamma Detector 14-16 [tR/hr (concrete encased pipes of various diameters and S/N 156626 PVC pipe) compositions.

17-18 hIR/hr (soil encased PVC pipe) 12-13 [,R/hr (soil encased steel pipe) 17-20 [tR/hr (soil encased aluminum pipe)

Ludlum Ludlum Model 44-9 Four Ranges 09-10-01 21.05%

60-140 (concrete)

Active Probe Area = 15cm 2 Model 3 15cm2 beta/gamma probe 0-500,000 cpm 80-120 (asphalt)

Used for beta/gamma surveying.

S/N 139180 S/N 145973 Ludlum Ludlum Model 44-9 Four Ranges 09-29-99 80-120 (concrete)

Active Probe Area = 15cm2 Model 3 15cm 2 beta/gamma probe 0-500,000 cpm a portion of linac Used for beta/gamma surveying.

S/N 15055 S/N 76109 land was surveyed in 24.23%

1999 Ludlum Ludlum Model 43-64 Four Ranges 09-24-01 21.58%

0 - 20 cpm Active Probe Area = 50cm 2 Model 12 Alpha Scintillator 0-500,000 cpmn MDA = 218 dpnVl00 cm2 Used for alpha surveying.

S/N 91103 ZnS (Ag)

S/N 092192 Canberra Gas Flow Proportional Canberra Model 2404 Low Level o/W Low Level Detector N/A As needed 30%

Varies with Sample gas proportional counting system used to o:/03 Counter count wipes for removable Model 2404 contamination. Results are usually reported as dpm/ I00cm2.

Canberra High Purity Varies with Gamma Spectroscopy MCA system Gamma Germanium Detector N/A As needed Sample Varies with Sample using a high purity Germanium detector.

Spectroscopy System T-5

Table 4: Gamma Spectroscopy Results of Background Soil (Surface) Samples Radionuclide Concentrations (pCi/gm) - Results +/- 2a-30 Minute Counts Sample 137CS 60co 228Th 232 Th Total 238u 235U ID 661.6 keV 1173 keV peak 238 keV peak 911 keV peak Thorium 63.3 (92.7) 144 (186) keV peak 22Th + 232Th keV peak peak X-1 ND ND 0.71+/- 0.07 0.97 +/- 0.25 1.69 1.17 +/- 0.77 (0.13 +/- 0.06)

X-2 ND ND 0.90 +/- 0.13 1.49 +/- 0.31 1.49 1.91 +/- 1.18 (0.13 +/- 0.08)

X-3 0.06 +/- 0.04 ND 1.49 +/- 0.10 1.56 +/- 0.25 3.05 1.45 +/- 0.80 (0.23 +/- 0.09)

X-4 ND ND 1.52 +/- 0.23 3.22 +/- 0.61 4.74 3.74 +/- 2.18 (0.28 +/- 0.17)

X-5 ND ND 1.92 +/- 0.17 2.41 +/- 0.53 4.33 (4.49 +/- 1.64)

(0.32 +/- 0.16)

X-6 ND ND 1.02 +/- 0.08 0.96 +/- 0.23 1.99 1.31 +/- 0.80 (0.14 +/- 0.06)

X-7 0.13_+/-0.08 ND 1.59_+/-0.14 2.40_+/-0.38 3.98 2.16_+/- 1.48 (0.18+/-0.10)

X-8 ND ND 1.44 +/- 0.28 1.40 +/- 0.28 2.84 2.30 +/- 1.16 (0.14 +/- 0.09)

X-9 0.09_+/-0.08 ND 0.89_+/-0.10 1.27_+/-0.31 2.15 1.59+/- 1.05 (0.10+/-0.08)

X-10 ND ND 1.29_+/-0.11 1.52_+/-0.36 2.80 1.10_+/-0.96 (0.16+/-0.08)

Soil samples were collected on 06/05/00 and 06/06/00 By Ed Rudgers off GA's site but close to GA.

Samples were counted 7/20/00 through 7/24/00 for 30 minutes (same count as the soil samples).

ND means:

< 0.1 pCi/g for Cs-137

< 0.1 pCi/g for Co-60 T-6 Notes:

1.
2.

3.

Table 5: LINAC Land Area Wipe Survey Results Wipe Gross a in Gross [ in Wipe Gross a in Gross P in No.

dpm/100 cm2 dpm/100 cm2 No.

dpm/100 cm2 dpmi/00 cm2 J&B Shop 20

<10

<10 1

<10

<10 21

<10

<10 2

<10

<10 22

<10

<10 3

<10 16.96 23

<10

<10 4

<10

<10 24

<10

<10 5

<10

<10 25

<10

<10 6

<10

<10 26

<10

<10 7

<10

<10 27

<10

<10 8

<10

<10 28

<10

<10 Land Area 29

<10

<10 1

<10

<10 30

<10

<10 2

<10

<10 31

<10

<10 3

<10

<10 32

<10

<10 4

<10

<10 33

<10

<10 5

<10

<10 34

<10 10.22 6

<10

<10 35

<10

<10 7

<10

<10 36

<10

<10 8

<10

<10 37

<10

<10 9

<10

<10 38

<10

<10 10

<10

<10 39

<10

<10 11

<10

<10 40

<10

<10 12

<10

<10 41

<10

<10 13

<10

<10 42

<10

<10 14

<10

<10 43

<10

<10 15

<10

<10 44

<10 10.22 16

<10

<10 45

<10

<10 17

<10

<10 46

<10

<10 18

<10

<10 47

<10

<10 19

<10

<10 48

<10

<10 T-7

Table 5: LINAC Land Area Wipe Survey Results (continued)

Wipe No.

Gross a in Gross P in Wipe Gross a in Gross P in dpm/100 dpm/100 cm2 No.

dpm/100 cm2 dpm/100 cm2 cmr 49

<10

<10 I1

<10

<10 50

<10

<10 12

<10

<10 51

<10

<10 13

<10

<10 52

<10

<10 14

<10

<10 53

<10

<10 15

<10

<10 54

<10

<10 16

<10

<10 55

<10

<10 17

<10

<10 56

<10

<10 18

<10

<10 57

<10

<10 19

<10

<10 58

<10

<10 20

<10

<10 59

<10

<10 21

<10

<10 60

<10

<10 22

<10

<10 61

<10

<10 23

<10

<10 Storage Area 24

<10

<10 (Contractor yard) 1

<10

<10 25

<10

<10 2

<10

<10 26

<10

<10 3

<10

<10 27

<10

<10 4

<10

<10 28

<10

<10 5

<10

<10 29

<10

<10 6

<10

<10 30

<10

<10 7

<10

<10 31

<10

<10 8

<10

<10 32

<10

<10 9

<10

<10 33

<10

<10 10

<10

<10 34

<10

<10 T-8

Table 5: LINAC Land Area Wipe Survey Results (continued)

Wipe No.

Gross a in Gross Pin Wipe Gross a in Gross P in dpmnIO0 cm2 dpm/100 cm 2 No.

dpm/100 cm 2 dpm/100 cm 2 35

<10

<10 64

<10

<10 36

<10

<10 65

<10

<10 37

<10

<10 66

<10

<10 38

<10

<10 67

<10

<10 39

<10

<10 68

<10

<10 40

<10

<10 69

<10

<10 41

<10

<10 70

<10

<10 42

<10

<10 71

<10

<10 43

<10

<10 72

<10

<10 44

<10

<10 73

<10

<10 45

<10

<10 74

<10

<10 46

<10

<10 75

<10

<10 47

<10

<10 76

<10

<10 48

<10

<10 77

<10

<10 49

<10

<10 78

<10

<10 50

<10

<10 79

<10

<10 51

<10

<10 80

<10

<10 52

<10

<10 H&V Bldg.

53

<10

<10 1

<10

<10 54

<10

<10 2

<10

<10 55

<10

<10 3

<10

<10 56

<10

<10 4

<10

<10 57

<10

<10 5

<10

<10 58

<10

<10 6

<10 23.69 59

<10

<10 60

<10

<10 61

<10

<10 62

<10

<10 63

<10

<10 T-9

Table 6: LINAC Land Area Soil Sample ResultsI Radionuclide Concentrations (pCi/g)

Background Not Subtracted U-238 (63KeV, 93 keV used when 63 not present)

U-235 (144 keV,186 keV used when 144 keV is not present)

Cs-137 (662 keV)

Co-60

{(1170+1330)/21 keV Total Thorium Th-228 (238 keV), plus Th-232 (911 keV)

-I 1

i I

I I

i1 pCi/g error 20 pCi/g pCi/g error 20 pCi/g pCi/g error 20 pCi/g pCi/g error 20

+/-

pCi/g pCi/g error 20

+/- pCi/g I

LINAC-01-01 2.21 77.9 1.72 0.08 113.1 0.09 0.16 44.6 007 ND 0.00 1.90 26.4 0.50 13 2

LINAC-01-02 1.05 106.3 1.12 0.14 75.6 0.11 0.22 55.1 0.12 ND 0.00 2.71 17.9 0.49 13 3

LINAC-01-03 0.99 111.6 1.10 0.16 47.1 0.08 ND 0.00 ND 0.00 2.77 16.4 0.45 15 4

LINAC-01-04 1.79 87.2 1.56 0.18 58.0 0.10 0.09 80.1 0.07 ND 0.00 3.68 17.6 0.65 15 5

LINAC-01-05 1.47 93.6 1.38 0.24 47.9 0.12 0.22 54.8 0.12 0.06 89.5 0.05 3,38

17. I 0.58 15 6

LINAC-01-06 1.12 88.9 1.00 0.16 64.3 0.10 ND 0.00 ND 0.00 3.07 17.2 0.53 15 7

LINAC-01-07 2.35 34.1 0.80 0.16 49.8 0.08 0.15 75.2 0.11 NI) 0.00 3.52 12.8 0.45 16 8

LINAC-01-08 3.)4 31.7 0.96 0.19 56.5 0.11 ND 0.00 ND 0.00 4.58 11.8 0.54 13 9

LINAC-01-09 2.02 86.1 1.74 0.23 58.7 0.14 ND 0.00 ND 0.00 4.76 13.1 0.62 15 10 LINAC-01-10 1.')7 33.3 0.66 0.23 40.4 0.09 ND 0.00 ND 0.00 3.89 11.2 0.44 15 11 LINAC-01-11 1.46 72.8 1.06 0.16 59.2 0.09 ND 0.00 ND 0.00 3.68 12.1 0.45 14 12 LINAC-01-12 2.86 44.2 1.26 0.20 41.6 0.08 NI) 0.00 ND 0.00 3.92 13.3 0.52 14 13 LL-I-St Drain 1.35 84.4 1.14 0.18 66.5 0.12 ND 0.00 ND 0.00 3.69 13.2 0.49 NA 14 LL-2-St Drain 0.89 108.7 0.97 0.18 45.2 0.08 0.33 24.0 0.08 ND 0.00 2.92 17.7 0.52 NA 15 LL-3-St Drain 1.27 91.9 1.17 0.15 47.7 0.07 0.19 46.1 0.09 ND 0.00 2.86 16.0 0.46 NA 16 LL-4-St Drain 1.2-6 79.2 1.00 0.14 52.2 0.07 0.17 46.6 0.08 ND 0.00 2.63 14.6 0.38 NA 17 LL-5--St Drain 1.26 61.9 0.78 0.06 117.4 0.07 0.19 37.6 0.07 ND 0.00 1.69 24.0 0.41 NA 18 LL-6--St Drain 2.27 56.6 1.28 0.09 98.2 0.09 0.11 58.0 0.06 ND 0-00 2.27 17.8 0.40 NA T-1O Sample ID Exposure Rate in p1R/hr at 1 meter from surface

Figure 1: Torrey Pines (Main) Site Land Areas Bunker Yard Bldg. 21/27 Utility Pad Bldg.

HOT CELL SITE TORREY PINES NORTHEAST

& Land

\\ jo..

\\*\\,*.x-*-7.

\\

S_'_..,

7 X Building 2 K'

TORREY PINES EAST TFF UTILITY CORRIDOR A

'2C

'7 (C-



A



A





Building 9

"*/Building,

"\\N/

/

<-_*)

, /*

,N

"')

'I,

-7 7,

TORREY PINES SOUTH AV LINAC Building 25

& Land Building 1 B

V f

o

,/"'-

R-]

,0

0)

NO(D ii hi II 00 I

C-00 4u Qz Cd) ii

(-3 z

-J a

0S 0

C-,

Co C

Co

0)

C IF I Q

0

I, C

I,

2--

WU I

Ii m

GA a

0 II I

CO2-ii II I

Figure 4: LINAC Land. Locations and Results of Alpha Scan Measurements 0 = Drain

= Surveyed Area

1.

Survey results are in counts/minutes. Background is not subtracted.

2.

-25% of Asphalt and Concrete (parking lot and J&B storage yard area) surface was scanned for Alpha.

-100% of Asphalt and Concrete (storage area) was scanned for Alpha. Scan results in cross hatched area.

3.

Asphalt and concrete surfaces only. Asphalt Background range = 0-20 cpm, Concrete Background range = 0=21 cpm

Figure 5: LINAC Land. Locations and Results of Beta Scan Measuremonts 0 = Drain L

Z= Surveyed Area

1.

Survey results are in counts/minute (using the 434cm2 detector), background is not subtracted.

2.

-25% of Asphalt and Concrete (parking lot and J&B storage yard area) surface was scanned for Beta.

Scan results in cross hatched area.

-100% of Asphalt and Concrete (storage area) was scanned for Beta. Scan results in cross hatched area.

3.

Asphalt and concrete surfaces only. Asphalt Background range = 2175-2900 cpm. Concrete Background range = 1600-2036 cpm I !

Figure 6: LINAC Land. Locations and Results of Fixed Alpha Measurements

1.

The values are in cpm/50cm2 and indicate the approximate locations of measurements taken.

One minute fixed Alpha readings were taken.

Sr

= Drain EZ

= Surveved Area

2.

Asphalt and concrete surfaces.

Figure 7: LINAC Land. Locations and Results of Fixed Beta Measurements Two minute fixed Beta readings were taken.

The values are dpm/lOOcm2 and indicate the approximate locations of measurements taken.

2.

Asphalt and concrete surfaces.

S= Drain Z = Sunerved Area

Figure 8: LINAC Land. Locations and Results of Exposure Rate Surface Scans 26 in Pipe 20-27 18-23 18-23 18-23 18-23 in Pipe 12-14 )

15-22 Torrey Pines West (Released) 11-14 "13-15 in Pipe 11-14 18-22 11-14 13-15 12-15 15-22 12-14 15-21 12-14 12-14 14-1 12-14 0= Drain F

= SurveyedArea

1.

-25% of the ground surface was scanned for Gamma.

2.

The values are MR/hr and indicate the approximate locations of Exposure Rate Measurement Scans were taken in Drains and at the openings/surfaces of drains.

3.

Asphalt, soil and concrete surfaces.

I I N

S 1a 1(

Figure 9: LINAC Land. Locations and Results of Exposure Rate Measurements at 1 Meter 4Denotes Minimum to Maximum The values are pR/hr and indicate the approximate location of Exposure Rate Measurements taken ~-Ilm above ground surface.

0 = Drain

] =Surveyed Area

2.

Asphalt, soil and concrete surfaces.

Figure 10: LINAC Land. Locations of Removable Contamination Survey

= Drain

= Surveyed Area

1.
2.

3.

Survey results are provided in Tables 5.

The Numbers circled are the approximate locations of wipes taken.

Asphalt and concrete surface.

Figure 11:

LINAC Land. Soil Sample Locations and Exposure Rate Measurements at Soil Sample Locations (9 = Drain S=

Surveyed Area The Letter "S" circled are the approximate locations of Soil samples taken.

The Letter "LL' are locations of samples taken from drains.

3.

The values are pR/hr and indicate the approximate location of Exposure Rate Measurements taken -~m above ground surface at soil sample locations.

I I

Figure 12: LINAC Land, J & B Work Shop. Locations and Results of Alpha and Beta Scans Notes:

1.

-25% of the floor was scanned for Alpha and Beta. Scan results in cross hatched area.

2.

All concrete surface.

Figure 13: LINAC Land, J & B Work Shop. Locations and Results of Fixed Alpha Measurements

<20 Work Bench

<20 SHEL VES

<20 SHEL VES

<20

<20

<20 Table

1.

The values are cpm/50cm 2 and indicate the approximate locations of measurements taken.

One minute fixed Alpha readings were taken.

2.

All concrete surface.

Overhead Platform Building SHELVES SHELVES Co LU Co

<20 Work Bench

<20

<20 SHELVES

<20 U

Tables

<20 I

Notes:

Desk I

I

Figure 14: LINAC Land, J & B Work Shop. Locations and Results of Fixed Beta Measurements Overhead Platform Building

<313 SHEL VES SHELVES

<313

<313

<313

<313

<313 Notes:

1.

The values are dpm/lOOcm 2 and indicate the approximate locations of measurements taken.

Two minute (cp2m) fixed Beta readings were taken.

2.

All concrete surface.

Figure 15: LINAC Land, J & B Work Shop. Locations of Removable Contamination Survey Notes:

1.

Survey results are provided in Table 5.

2.

The Numbers circled are the approximate locations of wipes taken.

3.

All concrete surface.

Figure 16: LINAC Land, J & B Work Shop. Locations and Results of Exposure Rate Measurements Notes:

1.

The values are pR/hr and indicates the approximate location of Exposure Rate Measurements taken -1m above ground surface. Results are Underlined

2.

-25% of the floor was scanned for Gamma. Scan results given in cross hatched area.

3.

All concrete surface.

Figure 17: LINAC Land. Locations and Results of Fixed Beta Measurements and Beta Scans.

Concrete Pad Outside of Building 30, Room118 E

Room 118 420 342 403

<313 538 546 471 Concrete Pad 448 381 710 489 393 383 366 465 426 Notes:

1.

Beta scan Results were 3000-3300 cpm/434cm2

2.

The values are dpm/lOOcm 2 and indicate the approximate locations of measurements taken.

Two minute (cp2m) fixed Beta readings were taken.

3.

All concrete surface.

440

General Atomics' Final Radiological Survey Report For LINAC Land Appendix A Final Survey Plans

Page 1 of 4 October 3, 2000 Laura Gonzales/Bill L~onite c/z

(

C&.03 Final Radiological Survey Plan for Linac Land Back2round The Linac Land area is shown in Figure 1. This Final Radiological Survey Plan covers only the Linac Land, the land area shown in Figures 1 and 2. Figure 2 provides a view of the land area showing approximate locations where asphalt, vegetation or gunite surfaces exist and generally where hills and slopes exists. This figure also identifies the minimum survey locations. The Linac Land Area includes the land surrounding the Building 30/31 complex, a concrete structure that previously housed a cooling system for LINAC, and a workshop used by a Heating and Air Conditioning contractor. It does not include the Building 30/31 complex itself or the Linac North Land Area.

The sewage drain lines present within the Linac Land North Area are not being addressed in this Survey Plan.

Another survey plan(s) will address all sewage drain lines present in this land area.

There is no known radiologically contaminated areas within the Linac Land Area.

Survey Objectives and Responsibility The purpose of performing a final survey is to demonstrate that the radiological conditions within the Linac Land Area satisfy the NRC and State of CA guidelines for release to unrestricted use. The objectives include (1) to show that the average surface contamination levels for each survey unit are within the authorized value, (2) to show that the maximum residual activity ("hot spot" area) do not exceed three times the average value in an area up to 100 cm2 and (3) that a reasonable effort has been made to clean removable contamination and fixed contamination and (4) that the exposure rates in occupiable locations are less than 10 p.R/hr above background measured at 1 meter above the surface. Samples will be counted in the Health Physics laboratory (onsite). Surveys will be taken only by qualified Health Physics Technicians having a minimum of 3 years Health Physics Technician experience in accordance with this Plan. The survey and final report documenting the survey will be performed by GA's Health Physics group.

Classification of the Area There is no history of use with radioactive materials on this land area. At one time, a radioactively contaminated HEPA plenum was found in the storage area location shown in Figure 2. No asphalt or soil contamination was found in this area. However, due to the possibility that potentially contaminated equipment was stored here, this storage area was classified as a "non-suspect affected area".

All other areas within the Linac Land Area are "non-impacted", which do not require surveys to be performed.

However, some surveying will be performed in these areas.

Release Criteria (per GA Site Decommissioning Plan)

Concrete/Asphalt Surface Release Criteria There is no known radiologically contaminated area within the Linac Land area. If elevated levels are found above normal background levels, samples will be collected and analyzed in order to determine what the contaminant(s) is. At this time, the release criteria will be firmly established. In the meantime, GA will A:\\linac landklinac land final survey plan.wpd

Page 2 of 4 perform a survey such that, if enriched uranium or mixed fission/mixed activation products were present, they would be detected at levels below the release criteria.

The applicable guidelines for residual contamination on asphalt/concrete surfaces enriched uranium and mixed fission/mixed activation products are:

5,000 dpm c /100 cm2, averaged over a 1 m2 area 15,000 dpm W/100 cm 2, total, maximum in a 100 cm2 area 1,000 (X dpm/100 cm 2, removable activity Exposure Rate Measurements The guideline value for exposure rates measured at 1 m above the surface, is 10 1sR/hr above background.

Alert Levels Alpha Alert Values If the following "alert levels" are exceeded, notify HP Management so an evaluation can be performed and to evaluate if decontamination is required.

> 100 cpm alpha using the large area (434 cm 2) probe (check area with a hand-held alpha meter).

> 60 cpm using a h 50 cm 2 and-held alpha probe (- 600 dpmr/100 cm 2)

Beta Monitoring

>300 cpm above the appropriate background using the 434 cm 2 probe.

>200 cpm above the appropriate background using the 100 cm 2 probe.

>150 cpm above background using a portable GM detector.

Exposure Rate Measurements

> 25 I.LR/hr at surface

> 20 [.R/hr at 1 m Documentation Every survey conducted must be documented on a daily basis on a drawing showing the approximate locations surveyed. Include the results (including units), the technicians signature, date, instrument(s) used (including model and serial number of both the ratemeter and the detector), calibration due date,

% efficiency, background readings (if applicable) and any other applicable information.

AAlinac land'linac land final survey plan.wpd r

Page 3 of 4 Final Radiological Surveys Planned for the Linac Land Area (as of October 3, 2000)

Type of Survey/Activity Non-Suspect Affected Area Unaffected Areas Gridding Required?

No No Asphalt or Concrete Surfaces (1) 100 % c 10 % cc (Scan w/ 434 cm 2 alpha probe), including the Cooling System Structure and the Heating/Air Conditioning Work Shop.

Asphalt or Concrete Surfaces (1) 100 % 3 10% P3 (Scan w/ 434 cm-2 beta probe), including the Cooling System Structure and the Heating/Air Conditioning Work Shop.

Minimum number of Measurement every -2 m Measurement every - 7 m Measurements (3) (4)

Alternate between (1) a wipe, (2) an alpha fixed Alternate between (1) a wipe, (2) an alpha fixed measurement and (3) a beta fixed and alpha fixed measurement and (3) a beta fixed and alpha fixed measurement on all asphalt or concrete surfaces.

measurement on all asphalt or concrete surfaces, including the Cooling System Structure and the Heating/Air Conditioning Work Shop.

[LR/hr Readings @ surface 100% scan on all surfaces of the storage area shown in 25% scan in all flat, easy to scan areas, including structures, Figure 2.

10% scan on rest of the land area (slopes, hillsides, etc)

Soil Samples Collect 5 soil samples under the asphalt pavement in Collect -7 soil samples (under asphalt/concrete if needed) the approximate locations indicated on Figure-2 in the within the unaffected area as shown in Figure -2.

Storage Area.

  • 1 - Outside of Room 103 of Building 31
  • 1 - in the area Southeast of the Cooling System Structure.
  • 5 - in random areas A:\\linac land'linac land final survey plan.wpd

Page 4 of 4 Type of Survey/Activity Non-Suspect Affected Area Unaffected Areas Heating and Air Conditioning NA Survey 10% of inside surfaces, up to 6' from the floor:

Work Shop

-Exposure Rate surface scans

-alternate fixed cc, P3, Wipes

-Exposure Rate at 3 m from surfaces Drainage Areas Scan using a microR meter all drainage areas within the Linac Land Area Collect soil samples in every drainage area -every 2 m

[LR/hr Readings I every 3 m

@ I m from surface (1)

(2)

(3)

(4)

Clean surfaces to remove debris or dirt.

For removable measurements, take a 100 cm 2 wipe at each location and count using a low level alpha/beta counter.

For the fixed measurements:

For a measurements; use either the hand held alpha counter (minimum of -6 second count). Document all readings in cpm.

For 13 measurements; take a 2 minute count using the 100 cm 2 gas flow proportional detector (beta) with the Model 2221 ratemeter.

Document all readings and mark on a drawing the locations the readings were taken.

A "measurement" is either (i) a "fixed" radiation measurement representing total activity or (2) a wipe (removable activity).

A:\\linac land\\linac land final survey plan.wpd

Page 1 of 5 April 29, 2001 aura Gonzales/Bill LaBonte Revised Final Radiological Survey Plan for LINAC Land This revision to the Final Radiological Survey Plan for LINAC land includes survey requirements for storm drain systems not covered in the Final Survey Plan issued on October 3, 2000. This survey plan replaces the Final Survey Plan issued on October 3, 2000.

Background

The LINAC Land Area includes the land surrounding the Building 30/31 complex on the west and south, surrounding a concrete structure that previously housed a cooling system for LINAC, and surrounding a workshop used by a Heating and Air Conditioning contractor. It does not include the Building 30/31 complex itself or the Linac North Land Area. The Linac Land area is shown in Figure 1. A view of the land area showing approximate locations where asphalt, vegetation or gunnite surfaces exist and generally where hills and slopes exists is provided in Figure 2. This figure also identifies the minimum survey locations.

This Final Radiological Survey Plan covers the LINAC Land, (the land area shown in Figures 1 and 2),

the contractor workshop, and the cooling system structure mentioned above. Any sewer systems that may traverse this area will be the subject of a later survey plan.

There is no known radiologically contaminated areas within the LINAC Land Area, however, a piece of HEPA system plenum, stored in a fenced in area within the LINAC Land boundary, was surveyed and found to be contaminated with radioactive material. This storage area is identified on Figure-2.

This area will have surveys consistent with a non-suspect affected area classification performed in it.

Survey Objectives and Responsibility The purpose of performing a final survey is to demonstrate that the radiological conditions within the LINAC Land Area satisfy the NRC and State of CA guidelines for release to unrestricted use. The objectives include (1) to show that the average surface contamination levels for each survey unit are within the authorized value, (2) to show that the maximum residual activity ("hot spot" area) do not exceed three times the average value in an area up to 100 cm 2 and (3) that a reasonable effort has been made to clean removable contamination and fixed contamination and (4) that the exposure rates in occupiable locations are less than 10 [LR/hr above background measured at 1 meter above the surface.

Samples will be counted in the Health Physics laboratory (onsite). Surveys will be taken only by qualified Health Physics Technicians having a minimum of 3 years Health Physics Technician experience in accordance with this Plan. The survey and final report documenting the survey will be performed by GA's Health Physics group.

W:\\linac land\\linac land final surv. rev.wpd

Page 2 of 5 Classification of the Area There is no history of use with radioactive materials on this land area. At one time, a radioactively contaminated HEPA plenum was found in the storage area location shown in Figure 2. No asphalt or soil contamination was found in this area. However, due to the possibility that potentially contaminated equipment was stored here, this storage area was classified as a "non-suspect affected area All other areas within the Linac Land Area are "non-impacted", which do not require surveys to be performed. However, some surveying will be performed in these areas.

Release Criteria (per GA Site Decommissioning Plan)

Concrete/Asphalt Surface Release Criteria There is no known radiologically contaminated area within the LINAC Land area. If elevated levels are found above normal background levels, samples will be collected and analyzed in order to determine what the contaminant(s) is. At this time, the release criteria will be firmly established. In the meantime, GA will perform a survey such that, if enriched uranium or mixed fission/mixed activation products were present, they would be detected at levels below the release criteria.

The applicable guidelines for residual contamination on asphalt/concrete surfaces enriched uranium and mixed fission/mixed activation products are:

5,000 dpm/100 cm2, averaged over a 1 m2 area 15,000 dpm/100 cm2, total, maximum in a 100 cm2 area 1,000 dpm/100 cm, removable activity Exposure Rate Measurements The guideline value for exposure rates measured at 1 m above the surface, is 10 paR/hr above background.

Alert Levels Alpha Alert Values If the following "alert levels" are exceeded, notify HP Management so an evaluation can be performed and to evaluate if decontamination is required.

> 100 cpm alpha using the large area (434 cm2) probe (check area with a hand-held alpha meter).

> 60 cpm using a 50 cm2 hand-held alpha probe (- 600 dpm/100 cm2)

Beta Monitoring

>300 cpm above the appropriate background using the 434 cm 2 probe.

WAlinac land\\linac land final surv. rev.wpd

Page 3 of 5

>200 cpm above the appropriate background using the 100 cm2 probe.

>150 cpm above background using a portable GM detector.

Exposure Rate Measurements

> 25 VtR/hr at surface

>20 VtR/hr at 1 m Documentation Every survey conducted must be documented on a daily basis on a drawing showing the approximate locations surveyed. Include the results (including units), the technicians signature, date, instrument(s) used (including model and serial number of both the ratemeter and the detector), calibration due date,

% efficiency, background readings (if applicable) and any other applicable information.

W:Alinac land\\linac land final surv. rev.wpd

Page 4 of 5 Final Radiological Surveys Planned for the LINAC Land Area (as of April 27, 2001)

Type of Survey/Activity Non-Suspect Affected Area Non-Impacted Areas Gridding Required?

No No Asphalt or Concrete Surfaces (1) 100 % a 10 % cc (Scan w/ 434 cm2 alpha probe), including the Cooling System Structure and the Heating/Air Conditioning Work Shop.

Asphalt or Concrete Surfaces (1) 100 % 03 10 % P (Scan w/ 434 cm-n beta probe), including the Cooling System Structure and the Heating/Air Conditioning Work Shop.

Minimum number of Measurement every -2 m Measurement every - 7 m Measurements (I3) (4)

Alternate between (1) a wipe, (2) an alpha fixed Alternate between (1) a wipe, (2) an alpha fixed measurement and (3) a beta fixed and alpha fixed measurement and (3) a beta fixed and alpha fixed measurement on all asphalt or concrete surfaces.

measurement on all asphalt or concrete surfaces, including the Cooling System Structure and the Heating/Air Conditioning Work Shop.

ýLR/hr Readings @ surface 100% scan on all surfaces of the storage area shown in 25% scan in all flat, easy to scan areas, including structures, Figure 2.

10% scan on rest of the land area (slopes, hillsides, etc)

Soil Samples Collect 5 soil samples under the asphalt pavement in Collect -7 soil samples (under asphalt/concrete if needed) the approximate locations indicated on Figure-2 in the within the unaffected area as shown in Figure -2.

Storage Area.

  • l - Outside of Room 103 of Building 31 in the area Southeast of the Cooling System Structure.

o5 - in random areas W:\\linac land\\linac land final surv. rev~wpd

Page 5 of 5 Type of Survey/Activity Non-Suspect Affected Area Non-Impacted Areas Heating and Air Conditioning NA Survey 10% of inside floor surfaces:

Work Shop

-Exposure Rate surface scans

-alternate fixed cX, 03, Wipes

[

-Exposure Rate at 3 m from floor surface.

Drainage Areas Scan using a microR meter all accessible drainage areas and storm drains within the Linac Land Area Collect soil samples in every drainage area/storm drain where silt collected.

[tR/hr Readings 1 every 3 m

@ Lm from surface Clean surfaces to remove debris or dirt.

For removable measurements, take a 100 cm 2 wipe at each location and count using a low level alpha/beta counter.

For the fixed measurements:

0 For x measurements; use either the hand held alpha counter (minimum of -6 second count). Document all readings in cpm.

For P3 measurements; take a 2 minute count using the 100 cm2 gas flow proportional detector (beta) with the Model 2221 ratemeter.

Document all readings and mark on a drawing the locations the readings were taken.

A "measurement" is either (1) a "fixed" radiation measurement representing total activity or (2) a wipe (removable activity).

W:\\linac land\\linac land final surv. rev.wpd (I)

(2)

(3)

(4)

LT z

7i

General Atomic's Final Radiological Survey Report For LINAC Land Appendix B GA Confirmatory Survey

Appendix B LINAC Land GA Confirmatory Survey Description Following the completion of the LINAC Land Final Survey, a Confirmatory Survey was performed by a Health Physics Technician, not associated with the Final Survey, in accordance with an approved Survey Plan (attached).

The purpose of this survey was to confirm that the Final Survey was effective in identifying the radiological conditions of the area.

The internal Confirmatory Survey was conducted in accordance with an approved survey plan see attached. This survey consisted of three (3) equally spaced exposure rate measurements in the Non-Suspect Affected Area with a NaI(TI) detector held approximately 1 meter from the surface and a slow walking pace scan of the Non-impacted area with a NaI(T1) detector held approximately one (1) meter from the surface.

The highest exposure rate measurement in the Non-Suspect Affected Area was 13 hR/hr at 1 meter from the surface. The highest exposure rate measurement in the remainder of the LINAC Land Area was 24 [IR/hr at 1 meter from the surface. See the attached survey map.

All measurements were below the approved release criteria of 10 p.R/hr above background.

All measurements were in agreement with the final survey results and all measurements were below the applicable release criteria. See Appendix B for details.

Conclusion All of the Confirmatory Survey results indicated that activity levels on the LINAC Land Area are below the approved release criteria, which agrees with the Final Survey results.

Page 1 of 1 May 3, 2001 Laura Gonzales/Bill LaBoe, Confirmatory Survey Plan for Linac Land

Background

The majority of LINAC Land Area is classified as a Non-Impacted Area which, in accordance with the GA Site Decommissioning Plan, does not require a radiological survey, however a Final Radiological Survey for LINAC Land Area was completed in April, 2001. In the past, a contaminated ventilation plenum was found stored in an enclosed portion of the parking lot. This portion of the parking lot was classified as a Non-Suspect Affected Area. See Figure-1 for details.

The radiological Final Survey did not find any elevated activity levels or exposure rates above natural background levels. This confirmatory survey will be performed to verify the results of the Final Radiological Survey.

Survey Requirements This confirmatory survey will consist of exposure rate measurements only, as follows:

Enclosed parking lot Take three (3) equally spaced fixed exposure rate measurements with a micro-R meter held approximately 1 meter from the surface.

Open Land Areas With a micro-R meter held at approximately 1 meter from the surface, perform a slow walking scan of the entire accessible area (mainly paved areas, excluding steep hillsides and heavily vegetated areas). If any exposure rate ->_

20 p.R/hr is detected, take a fixed reading in that area.

Documentation Every survey conducted must be documented on a daily basis on a drawing showing the approximate locations surveyed. Include the results (including units), the technicians signature, date, instrument(s) used (including model and serial number of both the ratemeter and the detector), calibration due date,

% efficiency, background readings (if applicable) and any other applicable information.

W:\\LINAC LAND\\confirmatory survey.wpd

Lu (0)

C 0

Coo S

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Meter Information:

Model:........... LUDLUM 3 (2x2 Nal) y SN:................ 153551 PN:................ 155109 EFF:.............. N/A Cal.Due:........ July 04, 2001 BKND:........... Concrete....... 15-18 t.R/hr BKND:........... Asphalt.......... 17-19 pR/hr BKND:........... Soil................ 11-13 PtR/hr Signature Date:

t4ý

-i:

05-01-.

Denotes Route of [tR/hr scans at -1 meter from ground surface.

Results 11-20 mR/hr The values are pR/hr and indicate the approximate locations of Exposure Rate Scans and Fixed Measurements taken -Im above ground surface. Fixed Measurements Results are Undline S= Drain S=

Surveyed Area

+

GENERAL ATOMICS P 0. BOX 85608 SAN DIEGO, CA 92186-5608 (858) 455-3000

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