Text

Request to Release a Certain Portion of General Atomics Facility to Unrestricted Use & Delete It from License SNM-696: Namely, Area 4 of Sorrento Valley West Land Area
	ML030930107
Person / Time
Site:	07000734
Issue date:	03/18/2003
From:	Asmussen K; General Atomics
To:	Adams M, Kwok S; NRC/NMSS/FCSS, State of CA, Dept of Health Services
References
	-RFPFR, 696/CAL-3579
	Download: ML030930107 (80)
	v • d • e

_

GENERAL ATOMICS March 18, 2003 696/CAL-3579 VIA EXPRESS DELIVERY SERVICE Ms. Mary Adams, Fuel Cycle Licensing (In Duplicate)

Branch/Section 1 U.S. Nuclear Regulatory Commission Mail Stop T-8A33 Two White Flint North 11557 Rockville Pike Rockville, MD 20852-2738

Subject:

Docket No.70-734; SNM-696: Request to Release a Certain Portion of General Atomics' Facility to Unrestricted Use and Delete it from License SNM-696:

Namely, Area 4 of the Sorrento Valley West Land Area and Ms. Sudana Kwok (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 a Certain Portion of General Atomics' Facility to Unrestricted Use and Delete it from License 0145-37: Namely, Area 4 of the Sorrento Valley West Land Area

Dear Ms. Adams and Ms. Kwok:

As you are aware, 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' site in San Diego. GA has recently completed the Final Radiological Survey of Area 4 of the Sorrento Valley West Land Area.

The Sorrento Valley West Land Areas (Areas 1,2,3,4 and 5) are shown in Figure 1. Areas 1, 2 and 3 have already been released to unrestricted use by both the U.S. Nuclear Regulatory Commission (NRC) and the California DHS's Radiologic Health Branch (State). Area 5 is in the process of being surveyed and will be the subject of a future report. Area 4 occupies an area of approximately 33,350 ft2 (- 3,100 m2).

There is no history of use or storage of radioactive material on this land area; however detailed surveys were performed due to its proximity to the Nuclear Waste Processing Facility where radioactive waste is processed and packaged for shipment to an authorized low-level N, "v\\ssaD(

3550 GENERAL ATOMICS COURT, SAN DIEGO, CA 92121-1122 PO BOX 85608, SAN DIEGO, CA 92186-5608 (858) 455-3000

Ms. Mary Adams (NRC) and Ms. Sudana Kwok (State)

March 18, 2003 696/CAL-3579 Page 2 of 3 radioactive waste disposal facility. Fenced-in yard areas bordering this land area on the west and south were used to store packaged radioactive material awaiting shipment off site.

The only radiological contamination found during the final survey was one hot particle embedded in the asphalt nextto Building 42. The particle was removed and analyzed bygamma spectroscopyandthe predominant radionuclide identified was Cs-1 37. Comprehensive surveys around this area did not identify any other particles or radioactive contamination.

Enclosed is a GA report titled "General Atomics' Final Radiological Survey Report for Area 4 of Sorrento Valley West Land Area." This report documents the results of GA's comprehensive radiological survey measurements and sampling and analyses conducted on Area 4. These results demonstrate that radiation levels in Area 4 of Sorrento Valley West are essentially indistinguishable from normal background and, therefore, the area is well below the NRC-and State-approved criteria for release to unrestricted use.

Accordingly, GA hereby requests the NRC and the State to release Area 4 of the Sorrento Valley West Land Area, as described in the enclosed final survey report, to unrestricted use and delete it from GA's NRC and State of California special nuclear material and radioactive material licenses, respectively. In accordance with decisions made during joint NRC, State of California and GA meetings, the NRC has the lead for the regulatory release of Area 4 of the Sorrento Valley West Land Area.

If you should have any questions regarding this request, orthe enclosed report, please don't hesitate to contact Ms. Laura Q. Gonzales at (858) 455-2758, or me at (858) 455-2823. Your assistance in responding to this request is very much appreciated.

Very truly yours, xV a-A s,

Keith E. Asmussen, Ph.D., Director Licensing, Safety and Nuclear Compliance Figure 1:

Sorrento Valley West Areas 1, 2, 3, 4, and 5.

Enclosure:

GA report titled: "General Atomics' Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area," dated March 2003.

cc:

Dr. D. Blair Spitzberg, Chief, NMSS Branch 3, Region IV Mr. Wayne L. Britz, Fuel Cycle Inspector, NRC Region IV Ms. Kathleen Henner, State of CA, Brea, CA Dr. Mina Goeders, State of CA, Brea, CA Ms. Barbara Hamrick, State of CA, Brea, CA

+ GENERAL ATOMIC5 FINAL RADIOLOGICAL SURVEY REPORT FOR AREA 4 OF THE SORRENTO VALLEY WEST LAND AREA Prepared By: William LaBonte, Joseph Sullivan, Richard Stowell, and Laura Gonzales Survey Technicians: Scott Cowan, Richard Stowell and Joseph Sullivan March 2003

Table of Contents INTRODUCTION........................................

SITE DESCRIPTION.....................................

HISTORY & CLASSIFICATION............................

History Classification......................................

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

As Low As Reasonably Achievable (ALARA)............

Facilities and Equipment (and Asphalt or Concrete Surfaces)

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

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

INSTRUMENTATION & BACKGROUND MEASUREMENTS...

Background Measurements for Instruments/Detectors Background Soil Concentrations of Concern.............

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

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

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

Survey Plans.......

Storm Drain Silt Sampling...........................

SURVEY

SUMMARY

I I

I 2

2 2

..................... 3 3

........................ 3

........................ 4

........................ 5

........................ 6

....................... 7 Comparisons of Site Decommissioning Plan Requirements with Final Surveys Performed on Area 4 of the Sorrento Valley West Land Area.............

................... 7 RESULTS OF THE FINAL SURVEYS...........................................

8 Non-Impacted Area 8

Scanning.........................................

.................... 8 Fixed Measurements (a and 3)................................................

8 Removable Activity...............................

8 Exposure Rate Scans...............................

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

9 Suspect Affected Area 9

Scanning..............................

........................ 9 Fixed Measurements (a and P)..............................

9 Removable Activity..............................

9 Exposure Rate Scans...............................

10 Fixed Exposure Rate Measurements...............................

10 Storm Drains................................

10 Storm Drain Silt Samples...............................

10 Exposure Rate Measurements...............................

II CONFIRMATORY SURVEYS...............................

12 CONCLUSION.........

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List of Tables Table 1:

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

................. T-I Table 2:

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

T-2 Table 3:

List of Instruments for Sorrento Valley South West, Area 4....

T-3 Table 4:

General Atomics Gamma Spectroscopy Results of Background Surface Soil Samples............................................

T-4 Table 5:

Sorrento Valley South West, Area 4, Soil Sample Results......

.............. T-7 Table 6:

Sorrento Valley South West, Area 4, Wipe Sample Results......

............. T-8 List of Figures (unpaged!

Figure 1:

Main Site and Sorrento Valley Site.

Figure 2:

Sorrento Valley West Land Area.

Figure 3:

Sorrento Valley South West, Area 4, Land Area.

Figure 4:

Sorrento Valley South West, Area 4, Land Area Dimensions.

Figure 5:

Sorrento Valley South West, Area 4, Lower Driveway Alpha Scan Locations and Results.

Figure 6:

Sorrento Valley South West, Area 4, Non-Impacted Upper Driveway Alpha Scan Locations and Results.

Figure 7:

Sorrento Valley South West, Area 4, Lower Driveway Beta Scan Locations and Results.

Figure 8:

Sorrento Valley South West, Area 4, Upper Driveway Beta Scan Locations and Results.

Figure 9:

Sorrento Valley South West, Area 4, Lower Driveway Fixed Alpha and Beta Measurement Locations and Results and Wipe Sample Locations.

Figure 10:

Sorrento Valley South West, Area 4, Upper Driveway Fixed Alpha and Beta Measurement Locations and Results and Wipe Sample Locations.

Figure II:

Sorrento Valley South West, Area 4, Lower Driveway Exposure Rate Scan Locations and Results.

Figure 12:

Sorrento Valley South West, Area 4, Upper Driveway Exposure Rate Scan Locations and Results.

Figure 13:

Sorrento Valley South West, Area 4, Hillside Exposure Rate Surface Scan Locations and Results.

Figure 14:

Sorrento Valley South West, Area 4, Hillside Fixed Exposure Rate Measurement Locations and Results.

Figure 15:

Sorrento Valley South West, Area 4, Lower Driveway Fixed Exposure Rate Measurement Locations and Results.

iii

Figure 16:

Sorrento Valley South West, Area 4, Upper Driveway Fixed Exposure Rate Measurement Locations and Results.

Figure 17:

Sorrento Valley South West, Area 4, Storm Drain Survey.

Figure 18:

Sorrento Valley South West, Area 4, Suspect Affected Area Alpha Scan Locations and Results.

Figure 19:

Sorrento Valley South West, Area 4, Suspect Affected Area Beta Scan Locations and Results.

Figure 20:

Sorrento Valley South West, Area 4, Suspect Affected Area Fixed Alpha and Beta Measurement Locations and Results and Wipe Sample Locations.

Figure 21:

Sorrento Valley South West, Area 4, Suspect Affected Area Exposure Rate Scan Locations and Results.

Figure 22:

Sorrento Valley South West, Area 4, Suspect Affected Area Fixed Exposure Rate Measurement Locations and Results.

Appendices Appendix A: Final Survey Plan, Sorrento Valley South West, Area 4, Land Area Appendix B:

Sorrento Valley South West, Area 4, Land Area Confirmatory Survey Plan.

Appendix C:

Sorrento Valley South West, Area 4, Land Area Confirmatory Survey Summary.

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GENERL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West 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 Area 4 of the Sorrento Valley West Land Area.

There is no history of use or storage of radioactive material on this land area. The only radiological contamination found during the final survey was one hot particle embedded in the asphalt next to Building 42. The particle was removed and analyzed by gamma spectroscopy and the predominant radionuclide identified was Cs-137. Comprehensive surveys around this area did not identify any other particles or radioactive contamination.

This report documents the results of GA's radiological measurements and soil sampling and analysis completed on Area 4 of the Sorrento Valley West 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 A view of GA's Main Site and Sorrento Valley Site is shown in Figure 1. The Sorrento Valley West Land Areas (Areas 1, 2, 3, 4 and 5) are shown in Figure 2. Areas 1, 2 and 3 have been released to unrestricted use by both the U. S. Nuclear Regulatory Commission (NRC) and the State of California DHS Radiological Health Branch (State). The Area 4 boundary is shown in Figures 2 and 3. The total land area to be released to unrestricted use in Area 4 is approximately 33,350 ft2 (- 3,100 in2 ), as shown in Figure 4. Area 5 is in the process of being surveyed and will be the subject of a future report.

As shown in Figure 4, Area 4 of the Sorrento Valley West Land Area includes the access road to portions of the Sorrento Valley site and roadways adjacent to Buildings 41, 42 and 37. Most of the area is paved with asphalt or concrete. A small area of vegetation lies behind and alongside Building 42.

History and Classification History There was no history of use or storage of radioactive material on this land area; however detailed surveys were performed due to its proximity to the Nuclear Waste Processing Facility (which is Page 1 of 12

4+ CENERAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area comprised of a portion of Building 41, a storage yard east of the Building and, until recently, included the land areas designated "Area 5" and a portion of "Area 2"; see Figure 2).

Radioactive waste is processed and packaged for shipment to an authorized low-level radioactive waste disposal facility. Fenced-in yard areas bordering "Area 4" on the west and south were used to store packaged radioactive material awaiting shipment off site.

Area 4 of Sorrento Valley West also includes land around Building 42. Until the early 1980's, Building 42 was used for neutron radiography.

Calibration of nuclear laboratory instruments was conducted in Building 42 for a short time, but that activity has since been discontinued in Building 42. GA's Quality Assurance Division now operates a Calibration Laboratory in Building 42. Building 42 has been released to unrestricted use. No radioactive material is used or authorized for use in this building.

There are storm drains and sewer systems traversing this land area. Final radiological surveys of the sewer system have been completed. (No radioactive material discernible from natural background was detected). The results of the sewer system surveys will be provided in a future report summarizing data from the radiological surveys of GA's Main Site and Sorrento Valley site sewer systems. The radiological surveys of the storm drains are included in this report.

Classification The entire area (approximately 33,350 ft2 or 3,100 M2 ) was initially classified as a Non-Impacted Area for radiological survey purposes.

During the performance of the final survey, a hot particle was discovered while performing beta surface scans in the area in front of Building 42. The radiation level was approximately 60,000 dpm/1 00 cm2 measured with a 100 cm2 gas flow proportional detector. Gamma spectroscopy analysis of this particle showed Cs-137 (the only radionuclide detected). The hot particle was removed from the asphalt surface and disposed of as low level radioactive waste after analysis.

All areas were then re-surveyed. Survey results after decontamination were at background levels.

A large area in front of Building 42 was re-classified as a Suspect Affected Area, the Final Survey Plan was revised, and this area (about 780 ft2 or -73 m2 ), was surveyed in accordance with survey requirements for a Suspect Affected Area. The remaining Non-Impacted Area is approximately 32,570 ft2 (- 3,030 M2 ).

Criteria for Release to Unrestricted Use As Low As Reasonably Achievable (ALARAM During decommissioning efforts, GA attempts to decontaminate to levels as close to Page2of 12

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CENMAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area "background" as possible and as far below the approved Soil Release Criteria as reasonably achievable.

Facilities and Equipment (and Asphalt or Concrete Surfaces)

The U.S. NRC's and the State of California's criteria for releasing facilities and equipment to unrestricted use are shown in Tables 1 and 2, respectively. The applicable guidelines for Cs-137 and Co-60 (and most beta/gamma emitters), and U-235 and U-238 (and their decay products), are as follows:

5,000 dpm/100 cm2, averaged over a 1 m2 area 15,000 dpm/100 cm 2, maximum in a 100 cm2 1,000 dpm/100 cm2, removable activity Release Criteria for Soils The predominant radionuclides found in the soil at GA 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 Thorium (Th-228 + Th-232) 10 pCi/g Depleted Uranium 35 pCi/g Cs-137 15 pCi/g Co-60 8 pCi/g Sr-90 1800 pCi/g If more than one radionuclide exists, the sum of the fractions of the concentrations (which must be less than or equal to one) is calculated as follows:

C1 t

-E=<I

,= I L1 where: C, = The average concentration levels of radionuclide i in the sample (above background).

L, = The release criteria for radionuclide 1.

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

Page 3 of 12

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GENEJRAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area Instrumentation and Background Measurements A list of instruments used to conduct the radiological surveys documented in this report 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. All calibrations are completed using only NIST traceable standards and approved procedures 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 found at Area 4 of the Sorrento Valley West 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:

Equation (5-2)

MDA 2.71 +4 65 (dpml cm 2) txExA Where:

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

E = efficiency A = area of the detector (cm2)

The MDA for scan surveys using the 434 cm2 gas flow proportional detector (floor monitor) was calculated using equation 5-3 from the draft NUREG/CR-5849 (modified in accordance with the discussion on page 5.8 of the draft NUREG/CR-5849).

Equation (5-3):

XxBR MDA =

(dpm/l OOcm 2 )

Ex1 100 Page 4 of 12

I+ GENERAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area Where:

X =

the multiple/portion of the background rate that can be discernable as an increase in instrument response by the surveyor (dependent on the type of instrument used).

BR=

background rate in (cpm)

E =

efficiency A =

area of the detector (cm2)

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; footnotes to Table 4 provide the locations where these samples were collected.

Exposure Rate Background Typical exposure rate background for GA's site using a Ludlum Model 19 micro R meter is 12-18.+/-Rlhr 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 [iR/hr (measured at I 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 surface are typically higher than measurements taken on soil due to the higher concentrations of naturally occurring radioactive material (NORM) in the asphalt. This background fluctuates depending upon the asphalt batch used and the date applied. An exposure rate background survey, (measured at 1 m from the surface), was performed at most Non-impacted Area paved surfaces at the GA site with the 2" x 2" NaI(TI) detector used to perform the exposure rate surveys during this final survey. The exposure rates ranged from 11-19 [tR/hr.

To compare radiation levels from inside the storm drain pipe to typical background levels in this type of geometry, background radiation levels were taken inside a drain line in GA's background pit (originally designed to compare trenches and pits on GA's Hot Cell Site). The background radiation level is 34 pRlhr.

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 Page 5 of 12

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GENERAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area 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 cm2, (3) to demonstrate silt drain sample results were well below GA's approved criteria for release of soil to unrestricted use, and, (4) that the exposure rate measurements taken in these areas, measured at 1 meter above the surface, were less than 1O [iR/hr above background.

Survey Plans A Final Survey Plan was developed based on the previous history of use of the buildings adjacent to Area 4 of the Sorrento Valley West Land Area, the radionuclides of concern for this area, the potential for contamination, the various types of surfaces encountered and the classification of the various areas. A copy of the Final Survey Plan(s) are provided in Appendix A.

Surveys were conducted 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 Every survey performed 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, instruments 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.

Storm Drain Silt Sampling A sample of silt was collected at each of the five (5) storm drain pits located in the Non-Impacted Area (a sixth Storm Drain pit was empty). Approximate locations of the storm drains are provided in Figure 17.

Each of the silt samples collected was approximately 1 kilogram in mass. The sampling locations were documented on a drawing. 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 silt 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.

The silt 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 only NIST traceable standards and is performance checked daily. Silt samples were counted for a minimum of 30 minutes each A 30 minute count was sufficient to Page 6 of 12

I+ CENERAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area 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 (pR/hr) and soil samples taken are provided as follows:

Comparisons of Site Decommissioning Plan Requirements with Final Surveys Performed on Area 4 of the Sorrento Valley West Land Area Survey Area"*

Gridding

of Direct

of Exposure Rate Surface Scans

of Soil Required Measurements Measurements on asphalt or Samples

?

Fixed a, tB or (gIR/hr) concrete Taken and Wipes on Analyzed concrete or asphalt D-Plan*

No Not Required Not Required Not Required Not Required Non-Impacted Areas A4 Surveys performed in No Fixed a = 64, 174 measurements at 10% surface Samples taken in Non-Impacted Areas Fixed 13 = 65, 1 m from the surface, scans each of 5 Storm e4 Wipes = 63, plus 25% surface for a and 3 Drain Pits scan and scans of Total = 190 Storm Drain Pit 5 samples total surfaces D-Plan*

Yes I per 4 M2, or, I I per 4 M2, or, I 100% of surfaces Not applicable, Suspect Affected every 2 m every 2 in Paved surfaces Area only in Suspect

-4 Total = 18 Total = 18 Affected Area Surveys performed in Yes Fixed a =8, 25 measurements at 100% surface No Soil Areas Suspect Affected lOM x IOM Fixed 3 =8, I m from the surface, scans for a and,

Areas 4

grids Wipes =8, plus 100% surface performed scan (-I" from Total =24 surface)

D-Plan = GA Site Decommissioning Plan The total surface area to be released is approximately:

Non-Impacted Area = 3030 m2 and Suspect Affected Area = 73 m2 Page 7 of 12

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CEMERAL ATOMiGS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area I Results of the Final Surveys The results of the Final Radiological Surveys performed in Area 4 of Sorrento Valley West Land are provided in figures and tables as noted below:

Non-Impacted Area Scanning 10% of the asphalt surface was scanned for a and P activity with large area (434 cm2) gas flow proportional detectors held within approximately I " of the surface. All a activity measurements (a= 0- 40 counts/minute) were at background levels. The P3 measurements ranged from 2100 to 3400 counts/minute. Background ranged from 2400 to 2900 counts/minute All P measurements were less than the MDA for the instrument used. All measurements were far below the approved release criteria. See Figures 5 and 6 for a survey locations and results, and Figures 7 and 8 for 3 survey locations and results. The scanning MDA for a was 82 dpm/1 00 cm2. The scanning MDA for,3 was 491 dpm/100 cm2.

Fixed Measurements (al and 13!

Sixty-four (64) fixed a and sixty-five (65) fixed P measurements were taken on asphalt surfaces.

The highest a measurement was at, or below, the natural background level (background = < 20 counts/minute).

The P measurements were not discernible from natural background; all results were less than the MDA (255 dpm/l00 cm2).

See Figures 9 and 10 for fixed a and p locations and results All measurements were not discernible from natural background levels and well below the approved release criteria.

Removable Activity 63 wipe samples were taken on asphalt surfaces and analyzed in the GA Health Physics laboratory for a and P activity. The highest a result was <20 dpm/100 cm2, the highest D result was <20 dpm/100 cm2. See Figures 9 and 10 for locations and Table 6 for results. All results were at background levels and well below the approved release criteria.

Exposure Rate Scans 25% of the area was scanned with a NaI(TI) detector held approximately I " from the surface.

The exposure rate ranged from 15 to 25 [LR/hr. Natural background is typically 17-19 p.R/hr for exposure rate scans at 1" from the surface. See Figures 11, 12, and 13 for locations and results Page 8 of 12

I CENERAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area Fixed Exposure Rate Measurements Fixed exposure rate measurements were taken inl 74 locations at 1 meter from the surface The exposure rate measurements ranged from 15 to 22,uR/hr over asphalt and 16 to 19 [tRIhr over soil. See Figures 14, 15 and 16 for locations and results. These measurements are not distinguishable from natural background levels and are, thus, well below the approved release criteria of 10 [tRJhr above the natural background range of 1 1-19 p.R/hr (asphalt) at GA.

Suspect Affected Area Scanning 100% of the asphalt surface was scanned for a and P activity with large area (434 cm2) gas flow proportional detectors held within approximately 1 of the surface. The a measurements ranged from 0 to 40 cpm on asphalt, which is background for asphalt, and 30 to 70 cpm on concrete.

Background for concrete ranged from 0 to 40 cpm. All areas with measurements higher than 60 cpm, as measured with a 434 cm2 gas flow proportional probe, had fixed measurements taken with a 50 cm2 probe. All measurements taken with a 50 cm2 probe were at, or below, natural background for concrete (less than 20 counts/minute). The scanning MDA for a was 82 dpm/100 cm2.

The D activity measurements ranged from 2200 to 2800 counts/minute on asphalt and 1802 to 2068 counts/minute on concrete. These measurement results are at or below natural background levels (2400 to 2900 counts/minute on asphalt and 1858 to 2036 counts/minute on concrete).

The scanning MDA for P was 491 dpm/100 cm 2 on asphalt and 361 dpm/I00 cm2 on concrete.

See Figures 18 and 19 for a and P scan survey locations and results.

Fixed Measurements (ac and l Eight (8) fixed a and eight (8) fixed 13 measurements were taken on asphalt surfaces The highest a measurement was background (background < 20 counts/minute). All results were less than the minimum detectable Activity (MDA) for the instrument(s) used. The MDA was 209 dpmlOO cm2.

The highest P3 measurement was 1320 cp2minutes (gross counts), which is background (Background = 1428 i 45 cp2minutes). All results were less than MDA (MDA=255 dpm/100 cm on asphalt and 213 dpmlOO cm2 on concrete ). See Figure 20 for results and locations. All measurements were at background levels and well below the approved release criteria.

Removable Activity Eight (8) wipe samples were taken on asphalt surfaces and analyzed in the GA Health Physics Page 9 of 12

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CENERAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley \\Vest Land Area laboratory for a and f3 activity. The highest cX result was <20 dpm/I 00 cm2, the highest P result was <20 dpm/100 cm2. See Figure 20 for locations and Table 6 for results.

All results were at background levels and well below the approved release criteria.

Exposure Rate Scans 100% of the area was scanned with a NaI(TI) detector held approximately 1 " from the surface.

The exposure rate ranged from 15 to 20.iR/hr on asphalt and 13 to 19 [iR/hr on concrete.

Natural background is measured with the instruments used for this survey was 18 to 20 ILR/hr for exposure rate scans at 1 " from asphalt surfaces and 1 5 to 18 IlR/hr on concrete. All measurements were at, or below, natural background. See Figure 21 for locations and results.

Fixed Exposure Rate Measurements Fixed exposure rate measurements were taken in twenty-five (25) locations at 1 meter from the surface. The exposure rate measurements ranged from 16 to 18 hR/hr over asphalt and 15 to 19 ILR/hr over concrete. These results are at, or below, the natural background range at GA and are, thus, well below the approved release criteria of 10 IJRIhr above natural background See Figure 22 for locations and results.

Storm Drains Storm Drain Silt Samples A total of five (5) silt samples were taken; one (1) in each of five (5) storm drain pits. A sixth storm drain contained no silt. See Figure 17, for locations and Table 5 for results. The results presented in Table 5 are summarized below:

238U in 235U in J 137CS in 228Th(212Pb) l 232Th( 228Ac) J 60co in

//_/__

pCi/g pCi/g pCi/g in pCi/g in pCi/g pCi/g High 154 + 1.30 0.19 + 0.07 0 07 +/- 0.07 1.24 +/- 0.16 1.38 + 0 33 MDA Low MDA MDA MDA 0 45 +/- 0.30 0.66 +/- 0 16 MDA Average 1.25 0.16 0.09 1.01 1.13 0.13 (N=5)

Nominal See Table 4 for background results and ranges, and a description of the locations I Background Iwhere background samples were collected Notes: 1. ND means not detected.

Page lOof 12

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CEAERAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area

2. Average Minimum Detectable Activity (MDA):

U-238 = 1.58 pCi/g (63 keV peak)

U-235 = 0.14 pCi/g (186 keV peak)

Cs-137= 0.13 pCi/g (662 keV peak)

Co-60 = 0.13 pCi/g (1173 keV peak)

Th-228 = 0.21 pCi/g (238 keV peak)

Th-232 = 0.43 pCi/g (911 keV peak)

3. The High concentrations for each isotope did not occur in the same sample.

4. No sample had a sum of fractions greater than 1.0.

5. The Average Activity is based on the numerical average of all (5) samples, using the Average MDA value when the isotope was not detected.

6. Background is not subtracted. See Table 4 for soil background information.

7. Silt sample locations are illustrated in Figure 17. Silt sample results are presented in Table 5.

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 only one (1) of the five (5) silt samples collected. The concentration (0.07 +/- 0.07 pCi/g) was not distinguishable from normal background concentrations of Cs-1 37 which range from ND to 0.31 pCi/g.

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

Co-60 was detected not detected in any sample.

Exposure rate measurements Fixed exposure rate measurements taken in the storm drain pits ranged from 22 to 29 [.R/hr which is typical for exposure rate measurements taken in small concrete structures in non-impacted areas. Exposure rate measurements taken in the storm drain trough, (identified as SVSW-Drain-4 on Figure 17), ranged from 22 to 33 [IR/hr. This trough is essentially an open sided pipe approximately 6-8" wide with a depth that increases from approximately 4" to approximately 18" towards the end with a drain pipe. The lower exposure rates were measured at the shallow end. Measurements taken inside of the pipe, (at the deep end), ranged from 32 to 37 P.R/hr. These measurements are consistent with natural background measurements (25 to 34

[LR/hr) taken inside pipes buried in a non-impacted area, using the same instrument that was used on this survey.

Page 11 of 12

I +

CENERAL ATOMICS Final Radiological Survey Report for Area 4 of the Sorrento Valley West Land Area I Confirmatory Survey Following the completion of the Final Survey, a Confirmatory Survey was performed by GA HP technicians. The internal Confirmatory Survey was conducted in accordance with an approved survey plan, see Appendix B.

All measurements were in agreement with the final survey results and all measurements were essentially indistinguishable from natural background levels, and, thus, well below the applicable release criteria. See Appendix C 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 Area 4 of the Sorrento Valley West Land Area is free of contamination above natural background levels and, therefore, meets the approved criteria for release to unrestricted use.

Page 12 of 12

Tablel:]

USNRC'S ACCEPTABLE SURFACE&CONTAMINATIONLEVELS 1

Naclies

-Aver~eb 4,

Maimum-d~f Removablle 4

(dinll~cj 2) dpnilOcm2

' (dpiu/lOOCM2)

U-nat, 235U, 238U, & associated decay products 5,000 a 15,000 a 1,000 a Transuranics, 226Ra, 228Ra 230Th 228Th, 231Pa 227Ac, 100 300 20 125i, 1291 Th-nat, 232Th, 'Sr, 223Ra, 224Ra, 232U, 126i, 133i 131i 1,000 3,000 200 Beta/gamma emitters (nuclides with decay modes other than alpha emission or spontaneous fission) 5,000 15,000 1,000 except 90Sr 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 cm2 and 1.0 mRad/hr at 1 cm2, respectively, measured through not more than 7 milligrams per square centimeter of total absorber.

T-1

'TabIe 2: STATE OREtCA ACCPTABLE SUACE CONTNAION LEVELS 1 J:

J AveNugedesM,-,u V

ve

f(dpminOc 2

(j/Oc ifOc~

U-nat, 235U, 238U, & associated decay 5,000 15,000 1,000 products Transuranics, 22 6 Ra, 228Ra, 230Th, 228Th, 100 300 20 23 'Pa, 227Ac, 1251, 129 Th-nat, 232Th, 9Sr, 223Ra, 224Ra, 232U, 1261, 1,000 3,000 200 133i, 131i Beta/gamma emitters (nuclides with decay modes other than alpha emission or 5,000 15,000 1,000 spontaneous fission) except 9Sr 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 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 cm2 and 1.0 mrad/hr at 1 cm2, 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-l" incorporated into GA's State of CA Radioactive Materials License.

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ae MAS43cmi'iOacmifi ctrs9Žl Ludlum,.

Ludlum Model 43-37 gas Four Linear Ranges 11/12/02 21 09%

10-40 cpm (asphalt)

Active Probe Area 434 cm2. The detector and rate meter Model 2221 (434cm') proportional 0-500,000 & one Log 10-40 cpm (concrete) are combined and mounted on a roll around cart The S/N 148425 -

Alpha detector 50-500,000 instrument features a static-flow system, quick connects, a S/N 086236 (CPM)

Scan MDA 82 dpmn/100 cm2 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 11/12/02 31 08%

2400 -2900 cpm (asphalt)

Active Probe Area = 434 cmo. The detector and rate meter Model 2221 (434cm2) proportional 0-500,000 & one Log Scan MDA = 491 dpm/l00 cm2 are combined and mounted on a roll around cart The SIN 84459 Beta detector 50-500,000 instrument features a static-flow system, quick connects, a S/N 086215 (CPM) 1858-2036 cpm (concrete) portable gas bottle and a means to adjust the height of the 6

Scan MDA = 361 dpm/1l00 cm 2 detector from the floor for optimum performance.

I Ludluni' Ludlum Model 43-68 Four Linear Ranges 06/23/02 34 95%

1428+/-45 cp2m (asphalt) 100Acm 2 gas flow proportional counter. Te detector and rate Model 2221 100 cm2 proportional 0-500,000 & one Log MDA= 255 dpm/lOOcm 2 meter are combined and mounted on a roll around cart The

-SIN 86302 Beta detector 50-500,000 instrument features a static-flow system, quick connects and a S/

424 (P)991

137 cp2m (Concrete) portable gas bottle SIN 12547 CPM)MDA=

213 dpmVIl00cm 2 Lulum

f.

Ludlum Model 43-64 Four Ranges 11/12/02 22 52%

0 - 20cpm (All Surfaces)

Active Probe Area =50cm2 Model 12 Alpha Sclotilator 0-500,000cpm MDA=209 dpm/lO0cm2 Used for Alpha surveying and fixed measurements SIN 138801 ZnS (Ag)

S/N 145696

Ludlum, Ludlum Model 44-10 Four Ranges 07/24/02 N/A 12-20 pR/hr surface vegetation 2 inch x 2 inch Nal (TI) scitillator Used for measuring Model 3' Nal (TI) Scintillator 0-500 pR/hr external dose rates on the surface and at one meter.

S/N 151348 sGamma Detector SIN 163169 Ludlum Ludlum Model 44-10 Four Ranges 07/09/02 N/A 12-19 pR/hr surface vegetation 2 inch x 2 inch Nal (TI) scintillator.

Used for measuring

'Model 3 Nal (TI) Scintillator 0-500 pR/hr 12-17 pR/hr @ I m vegetation external dose rates on the surface and at one meter.

SIN 153551 Gamma Detector S/N 155109 Ludlum,'

Ludlum Model 44-10 Four Ranges 08/12102 N/A 16-19 IpR/hr surface concrete 2 inch x 2 inch Nal (TI) scintillator. Used for measuring Model 3 Nal (TI) Scintillator 0-500 pR/hr 15-18 pR/hr @ Im concrete external dose rates on the surface and at one meter.

S/N 153590>'

Gamma Detector 19-21 pR/hr surface asphalt SIN 155190 18-20 pR/hrs Im asphalt 25-27 pR/hr trench l V

-. /

,a 34 pR/hr inside buried pipe Canberra Low,;

Gas Flow N/A As needed 30%

Vanes with Sample Canberra Model 2404 Low Level ca/P gas flow proportional Level /p Co unter Proportional Detector counting system used to count wipes for removable Model 2404 K contamination Results are usually reported as dpm/100cm2 Canberra Gamma'a High Purity N/A As needed Varies with Vanes with Sample Gamma Spectroscopy MCA system using a high purity Spectroscopy Germanium Detector Sample Germanium detector.

System.

T-3

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Table 4: General Atomics Gamma Spectroscopy Results of Background Surface Soil Samples September 24, 2002 137cs 6 0 Co 228Th 228Ra (32 Th)

Crotal) Th J 238u 23u Energy Peaks 661.6 keV 1173 keV 238 keV 911 keV 2 2 8 Th + 2 3 2 Th 63.3 (92.7) keV 144 (186) keV l'

(21 tPb)

(22 Ac)

(23Th)

_=

Sample ID Radionucilde Concentrations (pCl/g) - Results +/- 2o-30 Minute Counts Samples collected June, 2000 Re-analyzed November, 2001 X-1 ND' ND 0.49+0.15 1.25+/-0.34 1.74+0.48 ND ND X-2 ND ND 0.91 +/-0.23 0.91 +/- 0.23 1.81 +/-0.46 1.17+/-1.13 (0.09+/-0.05)

X-3 ND ND 1.40+/-0.27 1.79+0.37 3.19+/-0.63 1.51 +/- 1.20 (0.09+/-0.09)

X-4 0 08+0.07 ND 1.71 +/-0.31 2.08+/-0.47 3.78+/-0.78 ND (0.18+/-0.13)

X-5 ND ND 1.52 +/- 0.29 2.83 +/- 0.70 4.35 +/- 0.99 ND (0.20 +/- 0.15)

X-6 ND ND 1.14+0.32 1.12 +/- 0.26 2.25+/-0.58 ND (0.09+/-0.05)

X-7 0.11 +/-0.07 ND 1.68+/-0.24 2.18+/-0.47 3.86+0.71 ND (0.22+/-0.10)

X-8 ND ND 2.32+/-0.38 2.14+/-0.54 4.45 +/- 0.92 ND (026+/-0.14)

X-9 ND ND 0.61 +/- 0.15 1.59+/- 042 2.20+/- 0.57 ND ND X-10 0.09+/-0.06 ND 1.59+/-0.26 1.39+/-0.36 2.98+/-0.61 0.75 1.22 (0.13+/-0.07)

Samples collected and analyzed September, 2002 X-1l1 0.23+/-0.07 ND 1.37+/-0.29 1.71+/-0 37 3 07+/-0.66

[

1.13+/-1.30 (025+/-0.11)

X-12 0.31 I0.08 ND 0.50+/-0.08 0.65+/-0.18 1.14+/-0.26 j

ND (0.11 +/-0.07)

X-13 ND ND 0.95+/-020 j 1.13+/-0.23 2.08+/-0.43 l 1.29+/-0.99 (0.14+/-0.05)

ND = Energy peak not identified T-4

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X-15 ND ND 0.37 +0.09 0.56 +0.16 0.92 l 0.25 0.50 + 0.66 (0.04 +/- 0.04)

X-16 0.06+0.03 ND 0.97+0.22 1.15 0.23 2.12 +/- 0.45 ND (0.10+0.05)

X-17 ND ND 0.80 0.12 0.96+0.40 1.76+0.52 ND ND X-18 0.25 + 0.07 ND 0.77 + 0.21 0.94 0.24 1.71 + 0.45 0.92 +/- 0.94 (0.13 + 0.08)

X-19 ND ND 0.72+0.12 0.68+0.23 1.40+0.35 ND (0.11+0.07)

X-20 ND ND 1.42 +0.17 1.40 0.27 2.82 + 0.45 ND (0.20 + 0.09)

X-21 ND ND 1.51+0.32 1.48+0.30 2.99+0.62 2.47 + 1.71 0.26+/-0.23 X-22 0.07+0.05 ND 0.85+0.12 0.98+0.29 1.83+0.41 ND (0.10+0.08)

X-23 ND ND 1.17+0.15 1.33+0.28 2.50+0.42 ND (0.10+0.05)

X-24 ND ND 2.03+0.26 1.70+0.33 3.73*0.59 1.75+ 1.37 (0.17+0.06)

X-25 ND ND 1.44+0.29 1.36+0.28 2.80+0.57 1.52+ 1.26 (0.19+008)

X-26 ND ND 1.81 +0.24 141+0.31 3.22+0.54 0.68+0.96 (0 13+0.06)

X-27 ND ND 1.65+0.20 2.00+0.34 3.65+0.54 ND (0.15+0 07)

X-28 ND ND 1.40+0.20 1.47+0.33 2.87+0.54 1.35+ 1.03 (0.28+0.07)

X-29 0.01 + 0.07 ND 0.81 + 0.17 1 61 +0 34 2.42 + 0.51 ND (0 09 + 006)

X-30 ND ND 1.90+0 22 1.88+0 33 3.79+0.55 2.67+ 1.79 (0.35+0.11)

Range ND - 0.31 All ND 0.37 - 2.32 0.56 - 2.83 0.92 - 4.45 ND - 2 67 ND - 0.35 T-5

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Table 4 (continued): General Atomics Gamma Spectroscopy Results of Background Surface Soil Samples September 24, 2002 Sample Locations:

Xi Sorrento Valley Road near sample location ST65 on the hillside -I mile from Building 37.

X2 Sorrento Valley Road near Carmel Mountain Road junction on steep cliff.

X3 Sorrento Valley Road in Los Penasquitos Preserve -2 miles from Building 37.

X4 Sorrento Valley Court at the end of the road in the field.

X5 Roselle Street, East of sample location ST64 - 1/2 mile from Building 37 (collected on the hillside)

X6 Roselle Street, East of sample location ST64 -1 1/2 mile from Building 37 (collected on hillside).

X7 Lusk Boulevard, from the hillside - 1 1/2 miles from Building 37 (collected on the hillside).

X8 Vista Sorrento Parkway, -

I/z mile from Building 37 (collected on the hillside).

X9 Callahan Road, - 1/2 mile from Building 37 (collected on the hillside).

X10 Eastgate Mall road, -3 miles from Building 37 (collected in a field).

XII Creek Road (North County).

X12 Canyon de Oro (North County)

X13 Palomar (North E County).

X14 Deer Springs Rd. (North County).

X15 Rice Canyon Rd. (North County).

X16 Las Pulgas Rd. (North County).

X 17 Boderfield Park (South W County).

X1 8 Otay Mesa (South E County).

X19 Sunset Cliff (South W County).

X20 Marion Bear Park (South County)

X21 Mission Valley (South County).

X22 Santee (South E County)

X23 Ramona (East County).

X24 Via Abitura (San Diego).

X25 Black Mtn Park (San Diego).

X26 Park Village (San Diego).

X27 Harris Plant Rd (San Diego).

X28 Daley Center Dr. (San Diego).

X29 Harbison Canyon (East County).

X30 Apple St. (East San Diego).

T-6

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Tabl W Gammi Spectroscop jResuIts of SofrehtdVa1I@ South West Area 4-Storm Drain Silt Samples

>~,s, s

3 228u. 432 I

D 8

.'.f,2 Ene1rgy Pe112 910 kV 2 2.07 + 0.39' 63.6(97 he 04

(

0186 keY.O Range (Min ConcentrD-ions ND l

0.8Results

+/-27.30 Miut C

- Bakg o NDo Sub tra19ed 1ND ND 1.02 +/-0.13 1.05 +/-0.26 2.07 +/-0.39 0.69 +/-0.90 0.12 +/-0.05 2

ND ND 1.24 +/-0.16 1.31 +/-0.36 2.55 +/-0.52 1.15 +/-1.20 0.17 +/-0.06 3

ND ND 1.11 +/- 0.15 1.06 +/- 0.21 2.17 +/- 0.36 1.54 +/- 1.30 0.17 +/- 0.06 4

ND ND 0.87 +/-0.20 0.87 +/- 023 1.74 +/-0A43 1.52 +/-1.10 0.15 +/-0.06 5

10.07+/- 0.07 ND 0.80 +/-0.15 1.38 +/-0.33 2.18 +/-0.48 ND 0.19 +/-0.07 Range111111 (Min-Max)

ND -0.07 J

ND 0.80 - 1.24 0.87 - 1.38 1.74 -2.55 ND - 1.54 j

ND -O.19-Notes:

1.

ND means not detected.

2.

Average Minimum Detectable Activities (MDAs):

U-238 = 1.37 pCi/g (63 keV peak)

U-235 = 0.12 pCi/g (186 keV peak)

Cs-137= 0.10 pCi/g (662 keV peak)

Co-60 = 0.13 pCi/g (1173 keV peak)

Th-228 = 0.17 pCi/g (238 keV peak)

Th-232 = 0.38 pCi/g (911 keV peak)

T-7

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Table 6 (continued): Sorrento Valley South West tAr4Land Area Wipe Su r e, suls

<U

-,Y Sa mple 1aAtvyin P~Abtivitj-in-1~'Sapl

.a Acivity in If

~iiyi b

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Figure 1: Main Site and Sorrento Valley Site Building Numbers Names Building 1 Building 2 Building 7 Building 9 Building 10 Building 13 Building 14 Building 15 Building 19 Building 21 Building 22 Building 23 Building 25 Building 27 Building 27-7 Building 29 Building 29-2 Building 30 Building 31 Building 31-1 Building 31-2 Building 31-3 Building 33 Building 33-1 Building 33-5 Building 34 Building 34-1 Building 34-2 Building 34-3 Building 35 Building 35-1 Building 36 Building 37 Building 39 Building 39-1 Building 41 Building 42 Building 45 Building 63 Building 64 Building 65 Building 66 Building 66 Administration Science Laboratories A, B, C Cafeteria Expenmental Building Maintenance Building Technical Office Building Technical Office East Technical Office East Swimming Pool Building TRIGA Building TRIGA Fuel Lab Building Hot Cell Waste Yard Building Experimental Area Experimental Area Experimental Area Emergency Vehicle Storage Building LINAC Complex TRIGA Storage Building Neutron Radiography Building ECF Cntical Building Storage Building Fusion Building Fusion Lab Building Fusion Building Annex 5 Fusion Doublet IlIl Building Building Fusion Doublet Ill Capacitor Building Fusion Doublet Ill Lab Building Fusion Doublet IlIl Storage Building Test Tower Building Facilities (Shipping & Receiving) Building Blower Assembly Building Sorrento Valley Building Sorrento Valley Building Storage Building Raw Stock Facility NDT Facility Helium Circulator Test Facility 3550 Dunhill St 11030 Roselle St 11040 Roselle St

/

3520 Dunhill St

/

3510 Dunhill St

/

N W4E S

Sorrento Valley West Area 4 SITE OPEN SPACE SITE 1

I-L-

0 LOTS UCSD FENCING

-~

PROPERTY LINE 0

250 500 750 1000 SCALE IN FEET

Figure 2: Sorrento Valley West Land Area

ORRENTO VALLEY CENTRAL

\\ SORRENTO VALLEY SOUTH

Figure 3: Sorrento Valley West, Area 4, Land Area

-I UNRESTRI(

USE, SUSPECT

't Building I.Y Sto Stom

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Rebuilding N i

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Figitre 4: Sorrento Valley West, Area 4, Land Area Dimensions 4-I f,

/Building 37

\\

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Bunker ng It~a Waf X

5-N uk

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-\\-i 14 4

I I

storm drain E A 1 Figure 5: Sorrento Valley West, Area 4, Lower Driveway Alpha Scan Locations and Results dnveway 0- 30 0-20 Instrument Model LM 2221 Serial #

148425 Cal Due Date 11-12-02 Probe 434cm2 Probe #

086230 Efficiency 21.09%

Bkgd Asphalt 10-40cpm Scan MDA 82 dpm/1OOcm2 Scan MDA Data Ave.

25 cpm

Background

2 p

X 3

Scan MDA 82 dpm/100 cm2 Notes:

1. All readings are in cpm.

2. 10% of surface scanned.

Survey conducted by: R. Stowell Date: 05-31-02

Figure 6: Sorrento Valley Southwest, Area 4, Non-impacted Area Alpha Scan Locations and Results Bunker Yard Instrument Model Ludlum 2221 Senal #

148425 Cal Due Date 11-12-02 Probe 434 cm2 a Probe #

086236 Efficiency 21.09%

Bkgd asphalt 1 10-40 cpm Scan MDA Data Ave. Background 25 cpm X

3 Scan MDA 82 dpm/1 00 CM2 040 Bldg 42 0-40 Bldg 37 Bldg 41 Notes:

1. All readings are in CPM.

2. 10% of paved surface area scanned.

3. --

4 --

Denotes scan and range.

Survey Conducted by: R Stowell Date: 06-03-02

stonn drain m A Figure 7: Sorrento Valley West Area 4 Lower Driveway Beta Scan Locations and Results dnveway 2200-2600 II 2100-2600 Instruments Model LM 2221 Serial #

84459 Cal Due Date 11-12-02 Probe 434cm2 Probe #

086215 Efficiency 31.08%

Bkgd Asphalt 2400-2900 cpm Scan MDA 491 dpm/100 cm2 Scan MDA Data Ave. Background 2650 cpm X

0.25 Scan MDA 491 dpm/100 cm2 Notes:

1. 10% of surface scanned

2. All readings are in cpm.

3. All readings are < MDA unless noted.

Survey Conducted by: R Stowell Date: 05-30-02

Figure 8: Sorrento Valley West Area 4, Upper Driveway Beta Scan Locations and Results itT Instrument Model Ludlum 2221 Serial #

84459 Cal Due Date 11-12-02 Probe 434 cm2 D Probe #

086215 Efficiency 31.08%

Bkgd asphalt 2400-2900 Scan MDA Data Ave.

25 p

Backaround 2650 cpm X

0.25 Scan MDA 491 dpm/100 cm2 Bldg 42 Bldg 41 Notes:

2

1. All readings are in cpm.

2. All readings are less than scan MDA.

3. 10% of paved surface scanned.

4.

-# -P Denotes scan and range.

Surveyed Conducted by: R. Stowell Dates: 5-30-02 / 5-31-02

Figure 9: Sorrento Valley Southwest, Area 4, Lower Driveway Fixed Alpha and Beta Measurement Locations and Results, and Wipe Locations dnveway 120 1209

<20

<20 Instruments Model 2221 Lud 12 Serial #

86302 138801 Cal Due Date 06/23/02 11/12/02 Probe 100cm2 3 50Ccm 2a Probe #

142547 145696 Efficiency 34.95%

22.52%

Bkgd Asphalt 1428cp2m 0-20cpm MDA 255 dpm/100 cm2 209 dpm/100 cm2 Notes:

1.

< 20 Denotes alpha reading in cpm.

2. Maximum Alpha measurent = <20 cpm (<MDA).

3. [#### Denotes Beta readings in cp2m.

4. Maximum Beta measurement = 1119 cp2m (<MDA).

5. (+) Denotes wipe location.

6. Wipe results are provided in Table 6.

Survey Conducted by: J. Sullivan and R. Stowell Date: 06-03-02

Figure 10: Sorrento Valley West, Area 4, Upper Driveway, Fixed Alpha and Beta Measurement Locations and Results, and Wipe Locations and Results B

Yard

/()1141

'20 (E 1242

< 20 2)1394 I n

/

0 1160 O

< 20 1288 0

<'20 1485

/

1263

<20 O 1317

<20 (5

< 20 1194

< 20 1321

<20 1347

< 20 1229

<20 1329 Instruments 18

<20 1284

<20 1465

<20 Model Lud 12 Lud 2221

/

Serial #

138801 86302 1319

<20 1164

<20 1428 Cal Due Date 11-12-02 6-23-02 Probe 50 cm2 a 100cm2 1370

<20 1435

<20 Probe #

145696 142547

/

Efficiency 22.52 %

34 95%

<20 1423

< 20 1454

<20

Background

020 cpm 1428 +45 cp2m

<2 1

MDA 209dpm/100cm2 255dpm/1002

< 20

(

1474

<20 1185

/

1132

<20 8

1524 Bldg 42

/

1105

<20 8

1463

<20

<20 a

1129

<20

(

1207

<20 1113

<20

(

1073

<20

(

1119

<20 a

1151

<20 8

1159

<20 1122

<20 1185

<20 1194

<20 62 1118

<20 5

1124

<20 1157

<20 gate Bldg 41 Notes:

< 20 1053

<20

1.

<20 Denotes alpha reading in cpm.

14 984

<i20 1210 1047

< 20 (j'

111 stairs

\\...,

96

<20

2. Maximum Alpha measurent = <20 cpm (<MDA).

919

<20

3. #a# Denotes Beta readings in cp2m.

1095

<20

4. Maximum Beta measurement = 1524 cp2m ( <MDA).

I dnveway

5. (

Denotes wipe location.

6. Wipe results are provided in Table 6.

Survey Conducted by: J Sullivan & R. Stowell Dates: 06-04-02 to 06-05-02

storm drain R Figure 11: Sorrento Valley Southwest, Area 4, Lower L

ADriveway Exposure Rate Scan Location and Results driveway 1t.21 Instrument Model Ludlum 3 Serial #

153590 Cal Due Date 08-12-02 Probe 2"x2" y Probe #

155190 Efficiency N/A Bkgd Asphalt 19-21 RiR/hr I

22 Notes:

1. 25% of the surface scanned.

2. All readings are in pRIhr @ - 1".

Survey Conducted by: R. Stowell Date: 05-29-02

Figure 12: Sorrento Valley Southwest, Area 4, Upper Driveway Exposure Rate Surface Scan Location and Results Bunker Yard

) 9-

/

4 19-24 No*-

20-23 18-21 22-24 p

19-21

0 21-23 18-21 20-23 18-21 20-23 Instrument Model Ludlum 3 Serial #

153590 Cal Due Date 08-12-02 Probe 2"x2' y Probe#

1 155190 Efficiency N/A Bkgd asphalt 19-21 18-23 19-24 18-23 20-23 18-23 19-23 Bldg 42 15-20 10

.4 18-22 17-20 0

20-23 18-20 17-20 i

18-20 B

19-22 18-21 18-20 N

18-22 17-21\\

gate\\

6 1-20 18-21 l

E -

18-25 Bldg 37 Bldg 41 0

1 -22 staIrs 1-19-21 17-19 Notes:

1. All readings are in pIJR hr.

18-21

2. 25% of paved surface area scanned @ - 1".

L dnveway

3....

Denotes scan and range.

Survey Conducted by: R Stowell Dates: 05-29-02 to 05-30-02

F -

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Y' Figure 13: Sorrento Valley West Area 4 Hillside Exposure Rate Surface Scan Locations and Results

0J....

hole 18-21

=

I 04

.4 Area I

boundary I4 1<

\\

18-24 18-24 17-24 I

6 11~

fence I

17-22 I

_. J W

INSTRUMENTS Model Ludlum 3 Ludlum 3 Serial Number 153551 151348 Cal Due Date 07-09-02 07-24-02 Probe 2" X 2" Nal 2" X 2" Nal Probe Number 155109 163169

Background

12-19 itR/hr 12-20 Building 42 Notes:

1. 25% of the surface scanned.

Survey Conducted by. J. Sullivan & R. Stowell Date: 07-03-02

2. All readings are in pR/hr.

3. pR/hr reading of 30 is due to measurement taken inside of a hole

I--

I'-

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Figure 14: Sorrento Valley West, Area 4, Hillside Fixed Exposure Rate Measurements 1 18 1 18 I

18 17 18 17 17 17 17 18 1

I 18 4-04,+

17 18 18 17 18 17 17 I

I I

L-17 18 18 17 18 17 17 18 16 16 16 N%

17 l

I I

19 191 1

INSTRUMENT Model Ludlum 3 Serial Number 153551 Cal Due Date 07-09-02 Probe 2" X 2" Nal Probe #

155109

Background

12-17 pR/hr Survey Conducted by: J. Sullivan Date: 06-21-02

1. All readings are in pR/hr taken at - 1 meter above the surface.

mmnmm storm drain E m18 18 18 18 18 18 18 18 17 17 17 18 17 17 18 17 Figure 15: Sorrento Valley West, Area 4, Lower Driveway Fixed Exposure Rate Measurement Locations and Results driveway 18 18 18 18 18 18 19 18 Instrument Model Ludlum 3 Serial #

153590 Cal Due Date 08-12-02 Probe 2"x2" y Probe #

155190 Efficiency N/A Bkgd Asphalt 18-20 tR/hr

@ l m 19 19 Notes:

1. One measurement every - 3 meters.

2. All readings are in gR/hr @ - 1 meter.

19 18 18 19 19 19 18 17 gate

. _ _ Adr 18 18 16 Station 18 18 17 19 18 17 Survey Conducted by: R Stowell Date: 05-29-02

Figure 16: Sorrento Valley Southwest, Area 4, Upper Driveway Fixed Exposure Rate Measurement Location and Results Bunker Yard lc:L-117

16-20 I

I I

I 20-22 Instrument Model Ludlum 3 Serial #

153590 Cal Due Date 08-12-02 Probe 2"x2" y Probe #

155190 Efficiency N/A Bkgd asphalt 18-20 gR/hr 15-20 I

I I

I 19-21 Bldg 42 16-19 16-20 Bldg 37 Bldg 41 Notes:

16-20

1. All readings are in jAR/hr @ 1 meter.

2. Fixed measurements taken at every - 4 m, shown in ranges.

by: R. Stowell Date: 5-30-02

Figure 17: Sorrento Valley Southwest, Area 4, Storm Drain Survey 20 Yard Notes

1. All readings are in pRlhr.

2 The surface of each storm drain and inside pipe openings were scanned 3 Silt samples were collected where enough material was present Results are provided in Table 5 4 SVSW-Drain- # Denotes silt sample Survey Conducted by: J Sullivan & R Stowell Dates: 06-06-02 & 06-07-02

Figure 18: Sorrento Valley West, Area 4, Suspect Affected Area Alpha Scan Measurement Locations and Results concrte~:~Scai 20 50

\\.::>Ave Backgrot Scan MDW f

Instruments Model Ludlum 2221 QgriIf I

I A)r n MDA Data ind 25 cpm

=

3 A 82 dprnl1 00 CtT2 I

Ludlum 12 1

1 jQfnl 5 meters '\\

scllal~~~

rrI Wuw vIQQ I Cal Due Date 11-12-02 11-12-02 Probe 434 cm2 a 50 cm2 a Probe #

086236 145696 Efficiency 21.09 %

22.52 %

Bkgd asphalt 10-40 cpm 0-20 cpm Bkgd concrete 10-40 cpm 0-20 cpm Notes:

1. 100% of the surface was scanned using the 434 cm2 probe.

2. Results are shown in ranges, all measurements are < MDA.

3.

Denotes areas with a maximum of 60-70 cpm that were checked using the 50 cm2 probe. All readings were < 20 cpm.

Survey Conducted by: R Stowell Date: 06-06-02

Figure 19: Sorrento Valley West, Area 4, Suspect Affected Area Beta Scan Measurement Locations and Results 19026

\\::..::::Ae Bcgon Scan MA, Ave. Background x

Scan MDA, Co An et

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/

/...Ave.

Background

/

s

/o Scan MDA,

/\\

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/

Concrete Z

IDA Data 2650 cpm, Asphalt 0.25 491 dpml100 cm2 1947 cpm, Concrete 0.25 361 dpml100 cm2 5 meters "

I

\\

,1 Instrument Model Ludlum 2221 Serial #

84459 Cal Due Date 11-12-02 Probe 434cM2 IB Probe #

086215 Efficiency 31.08 %

Bkgd asphalt 2400-2900 cpm Bkgd concrete 1858-2036 cpm Notes:

1. 100% of the surface was scanned.

2. Results are shown in cpm ranges, all measurements were < MDA.

Survey Conducted by: J Sullivan Date: 06-06-02

Figure 20: Sorrento Valley West, Area 4, Suspect Affected Area Fixed Alpha and Beta Measurement Locations and Results, and Wipe Locations

":S..

A X.....

G 4 20.

<20 r#

8630220' 132 1107....

Moe

.ulu

.222...1

/m X2 eri...a...l....

8630,2 Cal Due Date 6-23-02 5meters P

1 cm2 10

,20 Probe #

142547 Efficiency 34.95%

Ludlum 12 138801 11-12-02 50 cm2 a 145696 22.52%

Bkgd asphalt 1428 + 45 cp2m 0-20 cpm Bkgd concrete 991 + 137 cp2m 0-20 cpm MDA Asphalt 255 dpm/100 cm2 209 dpm/100 cm2 MDA Concrete 213 dpm/100 cm2 209dpm/100 cm 2 Notes:

1. All Alpha measurements ( <20) were < 20 cpm (< MDA).

2. All Beta measurements (####) are shown in counts per 2 minutes (cp2m).

3. Maximum Beta measurement was 1320 cp2m, <MDA>

4. Wipe results are provided in Table 6.

Survey Conducted by: R Stowell Date: 06-05-02

Figure 21: Sorrento Valley West, Area 4, Suspect Affected Area Exposure Rate Scan Locations and Results SAA

,"asphalt Instrurr Model e sSerial# 7meri

.luo i.fla, ient Ludlum 3 153590 R-12 9n2

\\

'O' Probe 2W y Probe #

155190 Bkgd asphalt 19-21,uR/hr Bkgd concrete 16-19,R/hr Notes:

1. 100% of surface scanned.

2. Results shown in iR/hr ranges.

Survey Conducted by: J Sullivan Date: 06-04-02

Ficlure 22: Sorrento Valley West, Area 4, Suspect Affected Area, Fixed Exposure Rate Measurement Locations and Results 7...

1 7

A.......,

\\ :.......

17 1 7.

a.

s ph l X..

166 X~~.

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BLDG 42 ::..M5,...1 lo lo...'1 7,

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....... "17 19 177 16Instrument 5 meters "

Model l

Ludlum 3 Serial #

153590 Cal Due Date 8-12-02 Probe 2x2 y Probe #

155190 Efficiency N/A Bkgd asphalt 18-20 pR/hr Bkgd concrete 15-18 pR/hr Note:

1. All readings are pR/hr taken @ - 1 meter.

Survey Conducted by; J Sullivan Date: 06-04-02

General Atomics' Final Radiological Survey Report For Sorrento Valley West, Area 4, Land Area (a.k.a., Sorrento Valley Southwest Land Area)

Appendix A Final Survey Plan

Page 1 of 5 March 21, 2002 Prepared By: W. T. LaBonte Approved By:

JJA

)JW i L. Q. Gonzales Final Radiological Survey Plan for Sorrento Valley Southwest Land Area This Final Survey Plan is for Sorrento Valley Southwest Land area. This parcel of land is located in the GA Sorrento Valley Site. This land area includes the access road to the Sorrento Valley site, the roadways adjacent to Buildings 41, 42 and 37, and a fenced in area west of the roadways which includes a small storage bunker. See figure 1.

This Final Radiological Survey Plan covers open land areas, portions of which are paved with asphalt, and a small storage bunker.

The total surface area of this land area is approximately 38,470 ft2 (-3680 in2).

History and Classification This land area was is the main access to current and former buildings on the GA Sorrento Valley Site.

A portion of this land area, which is fenced in, was used to store radioactive material awaiting shipment and awaiting packaging for shipment off site. The remaining portions of this land area have no history of use or storage of radioactive material.

A characterization survey was completed in December 2001. During this characterization survey elevated activity levels were measured on the western land areas (radioactive material storage area) and the storage bunker. Decontamination efforts on this portion of the land area and the storage bunker were completed in February, 2002. Surveys taken in this area following remediation indicated all residual radioactivity was at, or near, natural background levels. No radioactivity above natural background levels was detected on the remaining portions of this land area.

The western portion of this land area, including the storage bunker, are classified as a "Suspect Affected Area". The remaining portions of this land area are classified as "Non-Impacted". The size of the "Suspect Affected Area" land area is approximately 5120 ft2 (-480 in2). The size of this area occupied by the storage bunker is approximately 227 ft2 (-21 M2 ). The size of the "Non-Impacted Area" is approximately 33,350 ft2 (-3100 i 2). See figure 2 for classification boundaries.

Survey Objectives and Responsibility The purpose of performing a final survey is to demonstrate that the radiological conditions within the Torrey Pines East 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 SVSW survey plan wpd

Page 2 of 5 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 FIR/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. The survey and final report documenting the survey will be performed by GA's Health Physics group.

Release Criteria (per GA Site Decommissioning Plan!

Concrete/Asphalt Surface Release Criteria The predominate isotopes associated with the storage bunker, based on the characterization survey results, is the Fission product Cs-137. The NRC release criteria for mixed fission and activation products is:

5,000 dpm /100 cm2, averaged over a I m 2 area 15,000 dpm /100 cm2, total, maximum in a 100 cm2 area 1,000 dpm/I 00 cm2, removable activity Exposure Rate Measurements The guideline value for exposure rates measured at I m above the surface, is 10 pR/hr above background.

Soil Sample Results The predominant radionuclides found in the soil at GA 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 Thorium (Th-228 + Th-232) 10 pCi/g Depleted Uranium 35 pCi/g Cs-137 15 pCi/g Cs-134 10 pCi/g Co-60 8 pCi/g Eu-152 11 pCi/g 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)

SVSW survey plan wpd

Page 3 of 5 Beta Monitoring

>300 cpm above the appropriate background using the 434 cm2 probe.

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

>150 cpm above background using a portable GM detector.

Exposure Rate Measurements

> 25,uRlhr at surface

> 20 stR/hr at 1 m Soil Sample Results Any soil sample result greater than 30% of the release limit.

Documentation I-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.

SVSW survey plan wpd

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Page 4 of 5 Final Radiological Surveys Planned for the Sorrento Valley Southwest Land Area Type of Survey/Activity Suspect Affected Area I

Non-Impacted Areas Gridding Required?

Yes, lOx 10 m grids on land area, IxIm grids inside No and outside surfaces of the storage bunker Asphalt or Concrete Surfaces (I) 100 % on land areas, 100% of internal and external 10% of paved surfaces (Scan w/ 434 cm22 alpha probe).

surfaces up to 2m in Storage Bunker, 25% above 2m.

Asphalt or Concrete Surfaces (I) 100 % on land areas, 100% of internal and external 10% of paved surfaces (Scan w/ 434 cm' 2 beta probe) surfaces up to 2m in Storage Bunker, 25% above 2m.

Minimum number of I measurement per 4 in2, or, I measurement per 20m2, or, Measurements (2) (3) 1 measurement every -2 in I measurement every -4 ml Alternate between (1) a wipe, (2) an alpha fixed Alternate between (1) a wipe, (2) an alpha fixed measurement measurement and (3) a beta fixed and alpha fixed and (3) a beta fixed and alpha fixed measurement on all measurement on all asphalt or concrete surfaces, asphalt or concrete surfaces. Total Number of measurements including the external and internal surfaces of the

= 155 Storage Bunker up to 2m from the floor. Total number of measurements on land = 94 ( based on 372 m2 asphalt area) and 14 on inside surfaces of Storage Bunker up to 2m, and 9 on external surfaces upto2m. Total= 117.

lIR/hr Readings, Scans 100% scan on all surfaces, detector held -1 " from 25% scan in all areas.

surface l.R/hr Readings I every 2m I per 10 m2 or I every -3m.

( I m from surface Soil Samples 20 as shown on Figure-4 None Storm Drains None

!00% exposure rate scan at the surface of storm drain vaults, plus, I soil sample of bottom sludge if present.

Notes:

(I)

(2)

Clean surfaces to remove debris or dirt.

For the fixed measurements:

For a measurements; use either the hand held alpha counter (minimum of-6 second count)

Document all readings in cpm.

SVSW survey plan wpd

Page 5 of 5 For,B 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.

For wipes, analyze each 100 cm2 wipe for a and P activity.

(3)

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

SVSW survey plan wpd

Figure 1: Sorrento Valley Southwest BI L I

UN,

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1' 1

41 Ace

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Page 1 of 5 March 21, 2002 Revised December 11, 2002 Prepared By: W. T. LaBonte Approved By:

O

)

L. Q. Gonzales Final Radiological Survey Plan for Sorrento Valley Southwest Land Area (Area 4)-Revision 1 Reason for Revision A "Hot Particle" was discovered southeast of Building 42, in an area occasionally used as parking spaces at the entrance to this Building, during the final radiological survey performed in accordance with this original survey plan. In addition, the initial final survey detected elevated activity levels in the fenced in area west of the roadways and in the small storage bunker, both of which will need additional remediation.

As a result of these conditions, the following changes to this survey plan were made:

1.

The classification of the area immediately southeast of Building 42, a 15 ft by 52 ft area, was changed from Non-Impacted to a Suspect Affected Area and the amount of surveying required was increased accordingly.

2.

Because the fenced in area west of the roadway and the storage bunker will need additional remediation that cannot be performed at this time, the land area previously known as the Sorrento Valley Southwest Land Area was divided into two(2) Land Areas, Sorrento Valley Southwest Area 4, which is the main roadways, and Sorrento Valley Southwest Area 5, which is the fenced in area and storage bunker. This survey plan addresses Area 4 only.

Scope This Final Survey Plan is for Sorrento Valley Southwest Land Area, Area 4. This parcel of land is located in the GA Sorrento Valley Site. This land area includes the access road to the Sorrento Valley site and the roadways adjacent to Buildings 41, 42 and 37. See figure 1.

This Final Radiological Survey Plan covers open land areas, portions of which are paved with asphalt.

The total surface area of this land area is approximately 33,350 ft2 (- 3,100 M2 ).

SVSW survey plan wpd

Page 2 of 5 History and Classification This land area is the main access to current and former buildings on the GA Sorrento Valley Site. A Health Physics Instrument Calibration Facility was located in Building 42. The remaining portions of this land area have no history of use or storage of radioactive material.

During the performance of the final survey in accordance with the Final Survey Plan, a "Hot Particle" was found imbedded in the asphalt immediately southwest of Building 42. This "Hot Particle" was removed and dsiposed of as low level radioactive waste. Surveys following remediation detected no activity above background. However, in accordance with the GA D&D Plan, this area is re-classified as a "Suspect Affected Area". The remaining portions of Sorrento Valley Southwest, Area 4 are classified as "Non-Impacted Areas". The Suspect Affected Area is approximately 780 ft2 (- 73 m2), the Non-Impacted Area is approximately 32,570 ft2 (- 3030 M2 ).

Survey Objectives and Responsibility The purpose of performing a final survey is to demonstrate that the radiological conditions within the Torrey Pines East 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 [tR/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. The survey and final report documenting the survey will be performed by GA's Health Physics group.

Release Criteria (per GA Site Decommissioning Plan)

Concrete/Asphalt Surface Release Criteria The predominate isotopes associated with the storage bunker, based on the characterization survey results, is the Fission product Cs-137. The NRC release criteria for mixed fission and activation products is:

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 cm2, removable activity Exposure Rate Measurements The guideline value for exposure rates measured at 1 m above the surface, is 10 piR/hr above background.

Soil Sample Results The predominant radionuclides found in the soil at GA and the approved release criteria in pCi/g SVSW survey plan wpd

Page 3 of 5 (above natural background concentrations) for these radionuclides are provided as follows:

Enriched Uranium (U-234 + U-235) 30 pCi/g Thorium (Th-228 + Th-232) 10 pCi/g Depleted Uranium 35 pCi/g Cs-137 15 pCi/g Cs-134 10 pCi/g Co-60 8 pCi/g Eu-152 11 pCi/g 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 cm2 probe.

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

>150 cpm above background using a portable GM detector.

Exposure Rate Measurements

> 25 VR/hr at surface

> 20 p.R/hr at 1 m Soil Sample Results Any soil sample result greater than 30% of the release limit.

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.

SVSW survyc plan wpd

I U

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1- -

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If1 Page 4 of 5 Final Radiological Surveys Planned for the Sorrento Valley Southwest Land Area Type of Survey/Activity l

Suspect Affected Area l

Non-Impacted Areas Gridding Required?

Yes, lOxIO m grids.

No Asphalt or Concrete Surfaces (

100 % on land areas.

10% of paved surfaces (Scan w/ 434 cmr2 alpha probe).

Asphalt or Concrete Surfaces (1) 100 % on land areas.

10% of paved surfaces (Scan w/ 434 cm22 beta probe)

Minimum number of I measurement per 4 m2, or, I measurement per 20m2, or, Measurements (2) (3) 1 measurement every -2 m I measurement every -4 m Alternate between (1) a wipe, (2) an alpha fixed Alternate between (1) a wipe, (2) an alpha fixed measurement measurement and (3) a beta fixed and alpha fixed and (3) a beta fixed and alpha fixed measurement on all measurement on all asphalt or concrete surfaces.

asphalt or concrete surfaces. Total Number of measurements Total number of measurements on land = 18 ( based

= 155 on 73 in2 asphalt area).

hR/hr Readings, Scans 100% scan on asphalt/concrete surfaces, detector 25% scan in all areas.

held -" from surface

[LR/hr Readings I every 2m I per 10 m2 or I every -3m.

@ Im from surface Soil Samples None None Storm Drains None

!00% exposure rate scan at the surface of storm drain vaults, plus, I soil sample of bottom sludge if present.

Notes:

(1)

(2)

Clean surfaces to remove debris or dirt.

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 P 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.

For wipes, analyze each 100 cm2 wipe for a and, activity.

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

(3)

SVSW survey plan wpd

Figure 1;Sorrento Valley Southwest, Area 4, Land Area Ad; t~~~unke\\a Buf <ding 37

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General Atomics' Final Radiological Survey Report For Sorrento Valley West, Area 4, Land Area (a.k.a., Sorrento Valley Southwest Land Area)

Appendix B Confirmatory Survey Plan

Page 1 of 3 February 3, 2003 Prepared By: W. T. LaBonte Approved By:

4gn A

J -t

. Gonzales Confirmatory Radiological Survey Plan for Sorrento Valley Southwest Land Area, Area 4 This Confirmatory Survey Plan is for Sorrento Valley Southwest Land Area, Area 4. This parcel of land is located in the GA Sorrento Valley Site. This land area includes the access road to the Sorrento Valley site and the roadways adjacent to Buildings 41, 42 and 37. See figure 1. The total surface area of this land area is approximately 33,350 ft2 (- 3,100 m2).

This Confirmatory Radiological Survey Plan covers only open land areas, the majority of which are paved with asphalt.

History and Classification This land area is the main access to current and former buildings on the GA Sorrento Valley Site. A Health Physics Instrument Calibration Facility was located in Building 42. The remaining portions of this land area have no history of use or storage of radioactive material.

During the performance of the final survey in accordance with the Final Survey Plan, a "Hot Particle" was found imbedded in the asphalt immediately southwest of Building 42. This "Hot Particle" was removed and dsiposed of as low level radioactive waste. Surveys following remediation detected no activity above background. However, in accordance with the GA D&D Plan, this area is re-classified as a "Suspect Affected Area". The remaining portions of Sorrento Valley Southwest, Area 4 are classified as "Non-Impacted Areas". The Suspect Affected Area is approximately 780 ft2 (- 73 M2) the Non-Impacted Area is approximately 32,570 ft2 (- 3030 in2).

Survey Obiectives and Responsibility The purpose of performing a confirmatory survey is to verify the radiological conditions identified during the Final Radiological Survey.

WASVSW Area 4 confirm wpd

Page 2 of 3 Release Criteria (per GA Site Decommissioning Plan)

Concrete/Asphalt Surface Release Criteria The NRC release criteria for mixed fission and activation products is:

1,000 dpm /100 cm2, averaged over a 1 m2 area 3,000 dpm /100 cm2, total, maximum in a 100 cm2 area 200 dpm/lOO cm2, removable activity The NRC release criteria for Alpha activity is:

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 cm2, removable activity Exposure Rate Measurements The guideline value for exposure rates measured at 1 m above the surface, is 10 ktR/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/lOO cm2)

Beta Monitoring

>250 cpm above the appropriate background using the 434 cm2 probe.

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

>40 cpm above background using a portable GM detector. (Note: this meter should ONLY be used in areas the 434cm2 or 100 cm 2probes will not fit).

Exposure Rate Measurements

> 25 HtR/hr at surface

> 20 jR/hr at 1 m Minimum Confirmatory Survey Requirements The minimum survey requirements for this confirmatory survey is as follows:

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Page 3 of 3 Type of Survey/Activity Suspect Affected Area Non-Impacted Areas Gridding Required?

Yes, lOx lO m grids.

No Asphalt or Concrete Surfaces (

100 % on land areas.

None (Scan w/ 434 cm22 alpha probe).

Asphalt or Concrete Surfaces (1) 100 % on land areas.

None (Scan w/ 434 cm22 beta probe)

Minimum number of I measurement per 4 in2, or, None Measurements (2) (3) 1 measurement every -2 in Alternate between (1) a wipe, (2) an alpha fixed measurement and (3) a beta fixed and alpha fixed measurement on all asphalt or concrete surfaces.

Total number of measurements on land = 18 ( based on 73 m2 asphalt area).

[tR/hr Readings, Scans 100% scan on asphalt/concrete surfaces, detector 10% scan in all areas.

held -I" from surface VR/hr Readings I every 2m I per 100 m2 or I every -30m.

@ I m from surface Soil Samples None None Storm Drains None None 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.

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General Atomics' Final Radiological Survey Report For Sorrento Valley West, Area 4, Land Area Appendix C Confirmatory Survey Summary P

Appendix C Sorrento Valley West, Area 4. Land Area GA Confirmatory Survey Description The Sorrento Valley West, Area 4, Land Area is illustrated in Figure 1. Following the completion of the Sorrento Valley West, Area 4, Land Area Final Survey, a Confirmatory Survey was performed by Health Physics Technicians in accordance with the approved Survey Plan provided in Appendix B.

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

This confirmatory survey performed and the results are as follows:

Alpha and Beta Scans in Non-Impacted Areas a and P3 scans were performed on -10% of the Non-Impacted Area paved surfaces using 434 cm2 gas flow proportional detectors. The a scan results ranged from 10 to 60 cpm which is less than the scan MDA of 82 dpm/lOOcm2. See Appendix C Figure 1 for a measurement locations and results The P scan results ranged from 2200 to 3350 cpm which is less than the scan MDA of 491 dpm/100 cm2. See Appendix C Figure 2 for f3 measurement locations and results.

Exposure Rate Fixed Measurements in Non-Impacted A ffected Areas Thirty-six (36) fixed exposure rate measurements were taken at I meter from the surface in Non-Impacted Areas using a 1" x I" NaI(Tl) detector held 1 meter from the surface. The highest measurement was 21 [.R/hr. Natural background, as measured with the instrument used, one meter from asphalt surfaces is 16 to 19,LR/hr. See Appendix C Figure 3 for exposure rate fixed measurement locations and results.

Alpha and Beta Scans in the Suspect Affected Area 100% of the Suspect Affected Area asphalt surfaces were scanned using a 434 cm2 gas flow proportional detector for both a and,3 activity. The a results ranged from 0 to 22 cpm (background was 10 to 40 cpm). These results are less than the scanning MDA of 82 dpm/100 2

cm.

See Appendix C Figure 4 for a scan survey locations and results. The,3 activity ranged from 2314 to 2860 cpm on asphalt and 1783 to 2111 cpm on concrete (background for asphalt was 2400 to 2800 cpm and 1655 to 1830 for concrete). These results are less than the MDA for asphalt (482 dpm/lO0 cm2) and for concrete (323 dpm/100 cm2). See Appendix C Figure 5 for f scan survey locations and results.

Fixed Alpha, Fixed Beta and Wipe Results in the Suspect A ffected Area Six (6) fixed a, six (6) fixed P3 measurements and six (6) wipe samples were taken in the Suspect Affected Area. The highest a measurement was <20 cpm (background was 0-20 cpm). The highest P measurement was 1155 cp2minutes which is less than the background level of 1371 Appendix C 1 of 2

cp2minutes. All wipe results were less than 20 dpmn/100 cm2. See Appendix C Figure 6 for fixed a and, locations and results and wipe locations. See Appendix C Table 1 for wipe results.

Surface Exposure Rate Scans in the Suspect A ffected Area 100 % of the paved surfaces in the Suspect Affected Area was scanned with a 2" x 2" NaI(TI) detector held within 1 " of the surface. The maximum exposure rate range on asphalt was 15 to 21 [LR/hr. The natural background range was 19 to 23 [IR/hr. The maximum exposure rate range on concrete was 15 to 20 IJR/hr. The natural background range on concrete was 12 to 20

R/hr. See Appendix C Figure 7 for locations and results.

Fixed Exposure Rate Measurements in the Suspect Affected Area Twenty-four (24) fixed exposure rate measurements were taken using a 2" x 2" NaI(Tl) detector held approximately 1 meter from the paved surfaces of the suspect affected area. The highest measurement was 18 ILR/hr on asphalt and 17,uRlhr on concrete. These measurements are at the natural background exposure rate of 17 to 20 [LR/hr on asphalt and 12 to 16 hR/hr on concrete.

See Appendix C Figure 8 for locations and results.

A summary of data (calibration dates, efficiencies, MDAs, etc) for the instruments used on this confinnatory survey is provided in Appendix C, Table 2.

Conclusion All of the Confirmatory Survey results indicated that activity levels on Area 4 of the Sorrento Valley West Land Area are below the approved release criteria, which agrees with the Final Survey results.

2 of 2

Appendix C Table 1:Sorrento Valley South West, Area 4, Land Area Confirmatory Wipe Survey Results Sample Number a Activity in dpm/lOOcm2 f3 Activity in dpm/lOOcm2 1

<20

<20 2

<20

<20 3

<20

<20 4

<20

<20 5

<20

<20 6

<20

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F-Appendix C, TABLE 2: LIST OF INSTRUMENTS for Sorrento Valley West Area 4 Confirmatory Survey Instrument Detector Range Calibration Due Efficiency

Background

Description (cpm, pR/hr)

Date MDA (100cm p & 50cm anl detectors only)

Ludlum Ludlum Model 43-37 gas Four Linear Ranges 02l17/03 20 98%

Active Probe Area = 434 cm' The detector and rate meter are Model 2221 (434cm 2) proportional 0-500,000 & one Log 10-40 cpm ( concrete) combined and mounted on a roll around cart The instrument S/N 97287 Alpha detector 50-500,000 I 0-40cpm (asphalt) features a static-flow system, quick connects, a portable gas S/N 083293 (CPM)

Scan MDA = 82 dpm/100 cm2 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 04/01/03 31 08%

Active Probe Area = 434 cm' The detector and rate meter are Model 2221 (434cm2) proportional 0-500,000 & one Log 1655 -1830 cpm ( concrete) combined and mounted on a roll around cart. The instrument S/N 154202 Beta detector 50-500,000 Scan MDA =323 dpm/l 00 cm2 features a static-flow system, quick connects, a portable gas S/N 149017 (CPM) 2400 -2800 cpm ( asphalt )

bottle and a means to adjust the height of the detector from Scan MDA =482 dpm/l 00 cm' the floor for optimum performance Ludlum Ludlum Model 43-37 gas Four Linear Ranges 02/25/03 31 08%

2400 -2900cpm(asphalt)

Active Probe Area = 434 cm' The detector and rate meter are Model 2221 (434cm') proportional 0-500,000 & one Log Scan MDA = 491 dpm/100 cm' combined and mounted on a roll around cart The instrument SIN 84459 Beta detector 50-500,000 1858-2036 cpm (concrete) features a static-flow system, quick connects, a portable gas S/N 086215 (CPM)

Scan MDA = 361 dpm/ I 00 bottle and a means to adjust the height of the detector from cm2 the floor for optimum performance Ludlum Ludlum Model 43-68 Four Linear Ranges 02/03/03 35 82%

100 cm2 gas flow proportional counter Model 2221 100 cm' proportional 0-500,000 & one Log 1042 + 90cp2m ( concrete)

SIN 84423 Beta detector 50-500,000 MDA-213 dpmn/1O0CM2 S/N 11944 B eCPM) 1371 + 55 cp2m (Asphalt)

SIN 19444 CPM)MDA:=

244 dpm/100cm2 Ludlum RCA 6199 Four Ranges 03/04/03 NA 13-17 pR/hr } I m, concrete I inch x I inch Nal (TI) scintillator Used for measuring Model 19 Nal (TI) Scintillator 0-5000 pR/hr 16-19 pR/hr @ Im, asphalt external dose rates on the surface and at one meter.

SIN 158881 Gamma Detector Ludlum Ludlum Model 44-10 Four Ranges 04/16/03 NA 12-20 pR/hr contact w/ concrete 2 inch x 2 inch Nal (TI) scintillator Used for measuring Model 3 Nal (TI) Scintillator 0-500 pR/hr 19-23 ptR/hr contact w/ asphalt external dose rates on the surface and at one meter S/N 151348 Gamma Detector 12-16 pR/hr @1 m, concrete S/N 163169 17-20 pR/hr lI m, asphalt Ludlum Ludlum Model 43-64 Four Ranges 04/18/03 21 21%

1 - 20cpm (All Surfaces)

Active Probe Area =50cm' Model 12 Alpha Scintilator 0-500,000cpm MDA=222 dpm/lOOcm' Used for Alpha surveying S/N 91056 ZnS (Ag)

S/N 75581 CanberraLow Level Gas Flow N/A As needed 30%

Varies with Sample Canberra Model 2404 Low Level a/p gas flow proportional a/p Counter Proportional Detector counting system used to count wipes for removable Model 2404 contamination Results are usually reported as dpm/lOOcm' Canberra Gamma High Purity N/A As needed Varies with Varies with Sample Gamma Spectroscopy MCA system using a high purity Spectroscopy System Germanium Detector Sample Germanium detector

Appendix C, Figure 1:

Sorrento Valley West, Area 4, Confirmatory I.,

Alpha Scan Locations and Results ISurveyed by-S Cowan IDate:

02103/03 l

Apppndix C, Figure 2: Sorrento Valley West, Area 4, Confirmatory Beta Scan Locations and Results

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J. Sullivan IDate 02/03103 l

Appendix C, Figure 3: Sorrento Valley West, Area 4, Confirmatory Fixed Exposure Rate Measurement Locations and Results I

I Noted All exposure measurements are recorded in iR/hr @ -1 Meter. Readings taken every - 30 ml Surveyed by S Cowan Date:

02/03/03

Appendix C, Figure 4: Sorrento Valley West, Area 4, Suspect Affected Area, Confirmatory Alpha Scan Measurement Locations and Results BLDG 42 concrete Instruments 5

Model 2221 Serial #

97287 Cal Due Date 02/17/03 Probe 434cm 2 a Probe #

083293 Efficiency 20.98%

Bkgd asphalt 10-40cpm I

Bkqd concrete 10-40cnm Scan MDA= 82 dpm/100 cm2 Notes: All measurements are recorded in counts per minute.

100% of the surface was scanned using the 434cm2 probe.

Surveyed by:

S. Cowan Date:

12/17/02

Appendix C, Figure 5: Sorrento Valley West, Area 4, Suspect Affected Area, Confirmatory Beta Scan Measurement Locations and Results BLDG 42 concrete 1940-2068

,11-asphalt 5 meters \\\\

Instruments Model 2221 Serial #

154202 Cal Due Date 04/01/03 Probe 434cm2 1 Probe #

149017 Efficiency 31.08%

Bkgd asphalt 2400-2800 Bkad concrete 1655-1830 Scan MDA= 482 dpm/100 cm2, Asphalt 323 dpm/1 00 cm2, Concrete Note: All measurements are recorded in counts per minute. 100% of area surveyed.

Surveyed by:

S. COWAN Date:

12/07/02

Appendix C, Figure 6: Sorrento Valley West, Area 4, Suspect Affected Area Confirmatory Fixed Alpha and Beta Measurement Locations and Results, and, Wipe Locations

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<20 Model Lud 2221 Serial #

84423 5 meCal Due Date 02/03/03 5 meters Probe 1 00 cm2 D xed Beta Location Probe#

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Efficiency 35.82%

Lud 12 91056 04/18/03 50 cm2 a 75581 21.21%

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() =Wipe Location Bkgd asphalt 1371 0-20 cpm Bkgd concrete 1042 f

0-20 cpm MDA Concrete 213 dpml OOcm 2 222 dpm/l1OOcm 2 MDA Asphalt 244 dpm/l1OOcm 2 222 dpm/l1OOcm 2

<20 =Fixed Alpha Location Notes:

All alpha measurements were < 20 cpm.

Two minute beta measurements are shown in total counts for two minutes, cp2m.

Wipe results are provided in Table 1.

Surveyed by:

S. Cowan Date:

12/23/02 - 12/24/02

Appendix C, Figure 7:

Sorrento Valley West, Area 4, Suspect Affected Area, Confirmatory Exposure Rate Scan Measurement Locations and Results Instruments Model LM-3 Serial #

151348 Cal Due Date 04116103 Probe 2x2 y Probe #

163169 Efficiency N/A Bkgd asphalt 19-23 ptRlhr @ 1" Bkgd concrete 12-20 OpR/hr @ 1" Notes: All exposure measurements are recorded in +/-R/hr @ - 1". 100% of area surveyed.

Surveyed by:

J.T. Sullivan Date:

06/04/02

Appendix C, Figure 8: Sorrento Valley West, Area 4, Suspect Affected Area, Confirmatory Fixed Exposure Rate Measurement Locations and Results BLDG 42 concrete 16 17 16 17 17 Instruments Model LM-3 Serial #

151348 Cal Due Date 04116/03 Probe 2x2 y Probe #

163169 Efficiency N/A Bkgd asphalt 17-20 pR/hr @ 1m r

Bkgd concrete 12-16 pR/hr @ 1 m______

Notes: All exposure measurements are recorded in gR/hr @ - 1 Meter, every 2 meters.

Surveyed by:

S. Cowan Date:

12/18/02

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Enclosure:

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