ML033020482
| ML033020482 | |
| Person / Time | |
|---|---|
| Site: | 07000734 |
| Issue date: | 10/23/2003 |
| From: | Asmussen K General Atomics |
| To: | Adams M, Kwok S Office of Nuclear Material Safety and Safeguards, State of CA, Dept of Health Services |
| References | |
| -RFPFR, 696/CAL-3660 | |
| Download: ML033020482 (58) | |
Text
+
GENERAL ATOMICS October 23, 2003 696/CAL-3660 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 5 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 5 of the Sorrento Valley West Land Area Ref:
Keith Asmussen Letter No. 696/CAL-3608 to Ms. Mary Adams (NRC) and Ms.
Sudana Kwok (CAL DHS), dated June 11, 2003: Request to Release a Certain Portion of General Atomics' Facility to Unrestricted Use and Delete it from License GA's NRC License SNM-696 and GA's State License 0145-37:
Namely, the Concrete Storage Bunker Located Within Area 5 of the Sorrento Va;lley West 1 and 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 5 of the Sorrento Valley West Land Area which is situated on GA's Sorrento Valley site.
Y YrSS a 3550 GENERAL ATOMICS COURT, SAN DIEGO, CA 92121-1194 PO BOX 85608, SAN DIEGO. CA 92186-5608 (619) 455-3000
Ms. Mary Adams (NRC) and Ms. Sudana Kwok (State)
October 23, 2003 696/CAL-3660 Page 2 The Sorrento Valley West Land Areas (Areas 1, 2, 3, 4 and 5) are shown in Figure 1.
Areas 1, 2, 3 and 4 have been released to unrestricted use by the U.S. Nuclear Regulatory Commission (NRC). Areas 1, 2 and 3 have been released by the California DHS's Radiologic Health Branch (State). GA is awaiting the release of Area 4 by the State.
Within Area 5 is a concrete storage bunker built around 1986 to provide shielding for packaged radioactive material. A separate report was submitted to the NRC and State requesting the release of the concrete storage bunker to unrestricted use (Ref. 1). The NRC has released the concrete bunker. GA is awaiting the release of the concrete bunker by the State.
Area 5 consists of the land area surrounding the concrete storage bunker, much of which is paved with asphalt. Vegetation covers the slopes on the west and south sides of Area 5. Area 5 covers an area of -9,760 ft2 (- 970 m2).
Asphalt and soil contamination was detected in this land area during the performance of the initial surveys. Decontamination consisted of removing the contaminated asphalt and soil and subsequently disposing of them as radioactive waste.
The primary contaminants were Cs-1 37 and Co-60. After remediation, radioactive concentrations in the soil were measured and found to be essentially indistinguishable from normal background levels. Similarly, radiation survey results of the asphalt/cement were at or near normal background levels.
Enclosed is a GA report titled "General Atomics' Final Radiological Survey Report for Area 5 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.
In accordance with decisions made during joint NRC, State of California and GA meetings, the NRC has the regulatory lead for the release of Area 5 of the Sorrento Valley West Land Area.
Accordingly, GA hereby requests the NRC and the State to release Area 5 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.
Ms. Mary Adams (NRC) and Ms. Sudana Kwok (State)
October 23, 2003 6961CAL-3660 Page 3 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.
Very truly yours, tG.-o(a.
+A-Keith E. Asmussen, Ph.D., Director Licensing, Safety and Nuclear Compliance
Enclosures:
- 1) Figure 1: Sorrento Valley West Land Areas 1, 2, 3, 4, and 5.
- 2)
GA report titled: "General Atomics' Final Radiological Survey Report for Area 5 of the Sorrento Valley West Land Area," dated October 2003.
cc:
Dr. D. Blair Spitzberg, Chief, NMSS Branch 3, Region IV Mr. Rick Mufioz, Fuel Cycle Inspector, NRC Region IV Ms. Kathleen Henner, State of CA, Brea, CA Mr. Tom Schell, State of CA, Sacramento, CA Ms. Barbara Hamrick, State of CA, Brea, CA
Date: 03/14/03 Figure 1: Sorrento Valley Site Land Areas SORRENTO VALLEY 0
I AREA 1 OF SORRENTO V WEST AREA 2 OF SORRENTO VALLEY WEST
( Southern Portion )
AREA 4 WEST SORRENTO VALLEY CENTRAL BUILDING 42 SVA BUILDING 37 SOUTH SOUTH SORRENTO VALLEY EAST Scale An Feet 0
200 400
GENERAL ATOMICS' FINAL RADIOLOGICAL SURVEY REPORT FOR AREA 5 OF THE SORRENTO VALLEY WEST LAND AREA Prepared By: William LaBonte, Will Schuck and Laura Gonzales Survey Technician: Richard Stowell and Will Schuck Confirmatory Technician: Greg Sayer October 2003
Table of Contents INTRODUCTION.........................................................
1 SITE DESCRIPTION.........................................................
2 Description of Site.........................................................
2 History of Use.........................................................
2 Decontamination Activities...................................................
2 Classification.........................................................
3 CRITERIA FOR RELEASE TO UNRESTRICTED USE.................................
3 As Low As Reasonably Achievable (ALARA)....................................
3 Facilities and Equipment (and Asphalt or Concrete Surfaces)........................
3 Release Criteria for Soils.....................................................
4 Exposure Rate Guideline.....................................................
4 INSTRUMENTATION & BACKGROUND MEASUREMENTS...........................
4 Background Measurements for Instruments/Detectors............................. 5 Background Soil Concentrations of Concern.....................................
5 Exposure Rate Background..............
6 FINAL SURVEYS PERFORMED..............
6 Objectives and Responsibilities...............................................
6 Survey Plans.
6 Soil Sampling.............................................................
7 SURVEY
SUMMARY
7 Comparison of Site Decommissioning Plan Requirements with Final Surveys Performed for Area 5 of the Sorrento Valley Area Land Area................................
8 RESULTS OF THE FINAL SURVEYS...............................................
8 Scanning.................................................................
8 Fixed Measurements (a and >)................................................
9 Exposure Rate Scans........................................................
9 Fixed Exposure Rate Measurements 9
Exposure Rate Measurements at Soil Sampling Locations...........................
9 Removable Activity.........................................................
9 Soil Samples.
9 CONFIRMATORY SURVEY......................................................
11 CONCLUSION.................................................................
11 List of Tables Table I:
USNRC's Acceptable Surface Contamination Levels.........................
T-l Table 2:
State of California's Acceptable Surface Contamination Levels.....
............ T-2 Table 3:
Sorrento Valley West Land Area, Area 5 List of Instruments.....
T-3 ii
Table 4:
General Atomics Gamma Spectroscopy Results of Background Surface Soil Samples.
TX Table 5:
Sorrento Valley West Land Area, Area 5, Wipe Sample Results......
......... T-7 Table 6:
Sorrento Valley West Land Area, Area 5, Soil Sample Results......
.......... T-8 List of Fiwures (unnaped)
Figure IA:
Figure IB:
Figure 2:
Figure 3:
Figure 4:
Figure 5:
Figure 6:
Figure 7:
Figure 8:
GA's Main Site and Sorrento Valley Site Sorrento Valley Site Land Areas Sorrento Valley West Land Area, Area 5 Sorrento Valley West Land Area, Area 5, Alpha Scan Locations and Results.
Sorrento Valley West Land Area, Area 5, Beta Scan Locations and Results Sorrento Valley West Land Area, Area 5, Fixed Alpha and Beta Measurement Locations and Results, and Wipe Survey Locations Sorrento Valley West Land Area, Area 5, Soil Sample Locations Sorrento Valley West Land Area, Area 5, Exposure Rate Scan Locations and Results Sorrento Valley West Land Area, Area 5, Exposure Rate Fixed Measurement Locations and Results Appendices Appendix A: Final Survey Plan, Sorrento Valley Land Area, Area 5 Appendix B:
Confirmatory Survey and Results iii
+
CENERAL ArW-Cs Final Radiological Survey Report for Area 5 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 5 of the Sorrento Valley West Land Area located on GA's Sorrento Valley Site. The Sorrento Valley West Land Area was divided up into 5 areas for survey purposes. Areas 1, 2, 3 and 4 have been released by the Nuclear Regulatory Commission (NRC) and Areas 1, 2 and 3 have been released by the State (DHS/RHB). GA is awaiting the release of Area 4 by the State.
A concrete storage bunker which was used to store packaged radioactive material is located within Area 5. This concrete storage bunker was decontaminated in early 2003 and was released to unrestricted use by the NRC on October 6, 2003.' GA is awaiting the release of the concrete bunker by the State. Area 5 consists of the land area surrounding the concrete storage bunker, much of which is paved with asphalt. Vegetation covers the slopes on the west and south sides of Area 5. Area 5 covers an area of -9,760 ft2 (- 970 M2).
Asphalt and soil contamination was detected in this land area during the performance of the initial surveys. Decontamination consisted of removing the contaminated asphalt and soil and subsequently disposing of them as radioactive waste. The primary contaminants were Cs-I 37 and Co-60. After remediation, radioactive concentrations in the soil were measured and found to be essentially indistinguishable from normal background levels. Similarly, radiation survey results of the asphalt/cement were at or near normal background levels.
GA is requesting both the Nuclear Regulatory Commission (NRC) and the State of California DHS Radiological Health Branch (DHS/RHB) to release this parcel of land to unrestricted use.
This report documents the results of GA's radiological measurements and soil sampling and analysis completed on Area 5 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.
' License Amendment No. 79 to NRC License No. SNM-696 dated October 6, 2003.
Page I of 11
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CEIVERAL AwMIcs Final Radiological Survey Report for Area 5 of the Sorrento Valley West Land Area Site Description Description of Site GA's Main Site and Sorrento Valley Site are shown in Figure lA. The Sorrento Valley Land Areas designated Areas 1, 2, 3, 4, and 5 are shown in Figures lB and IC in relation to other surrounding land areas and facilities.
A concrete storage bunker which was used to store packaged radioactive material is located within Area 5. This concrete storage bunker has been released to unrestricted use by the NRC.
GA is awaiting the release of the concrete bunker by the State.
Area 5 consists of the land area surrounding the concrete storage bunker, much of which is paved with asphalt. Vegetation covers the slopes on the west and south sides of Area 5. Area 5 covers an area of -9,760 ft2 (- 970 M2 ) which consists of the following:
Asphalt/Cement Trench
-4,284 ft2 ( 398 mi)
Soil 396 ft2 (37 m 2)
Soil w/ Vegetation Cover
-5,080 ft2 F-472 m2 )
Total
- 9,760 ft2 (- 970 M2 )
Figure 2 shows the boundary of Area 5 of the Sorrento Valley West Land Area and provides the dimensions for this land area.
History of Use Area 5 was used primarily for storing packaged radioactive material awaiting final disposition.
For example, some boxes containing radioactive waste were stored in Area 5 prior to shipment to an authorized low-level radioactive waste disposal site. In addition, some waste was re-packaged in this location prior to shipment. The storage and re-packaging activities were the likely cause of the asphalt and soil contamination found in Area 5.
Decontamination Activities Initially, there were only 4 areas within the Sorrento Valley West Land Area - Areas 1, 2, 3 and
- 4. During the survey of Area 4, radioactive contamination was found inside the concrete bunker and on the asphalt and soil north and west of the concrete bunker. GA then decided to divide Area 4 into two areas; Area 4 which was the area expected to be clean, and Area 5 which required remediation. The area 4 survey was completed and a report submitted to the NRC and Page 2 of 11
I +
CANEDR Arv-CS Final Radiological Survey Report for Area 5 of the Sorrento Valley West Land Area I
the State. Subsequently, the NRC performed a confirmatory survey and released the area to unrestricted use. GA is awaiting the State's release of Area 4.
Decontamination of Area 5 consisted of removing the contaminated asphalt and soil to the west of the concrete storage bunker and subsequent packaging and shipment of the asphalt/soil to the DOE's Nevada Test Site (an authorized low-level radioactive waste disposal site).
The primary contaminants were low-levels of Cs-] 37 and Co-60 found in the asphalt and soil as hot particles or localized "spots" of contamination. After remediation, no elevated levels of contamination were noted on the asphalt. The remaining soil was sampled and analyzed by gamma spectroscopy. Radioactive concentrations in the soil were found to be essentially indistinguishable from normal background levels.
Classification This land area has a long history of short term storage of radioactive materials awaiting shipment.
Radioactive contamination was found on the asphalt during initial surveys. Therefore, the area was classified as a Suspect Affected Area.
Criteria for Release to Unrestricted Use As Low As Reasonably Achievable (ALARM During decommissioning efforts, GA attempts to decontaminate to levels as close to "background" and as far below the approved Release Criteria (as identified in GA's Site Decommissioning Plan) as reasonably achievable.
Facilities and Equipment (and Asphalt or Concrete Surfaces)
The NRC-and State-approved release criteria for beta/gamma emitters (including Cs-137 and Co-60) is as follows:
5,000 dpm /100 cm', 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 Page3of 11
I c+ NrRAL AToMcs Final Radiological Survey Report for Area 5 of the Sorrento Valley West Land Area I 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 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 If more than one radionuclide exists, the sum of the fractions of the concentrations is calculated as follows:
C t
i= <1 f Li Where:
C, = The average concentration levels of radionuclide i in the sample (above background).
Li = The release criteria for radionuclide i.
The sum of the fractions must be less than or equal to one (1).
Exposure Rate Guideline Exposure rates measured at 1 m above the surface are not to exceed 10 pR/hr above natural background levels.
Instrumentation and Background Measurements A list of instruments used during the radiological surveys is shown in Table 3. The table includes: (1) a description of the instrument, model number and its serial number, (2) a description of the detector (if applicable) and its serial number, (3) instrument ranges, (4) calibration due dates, (5) typical background readings and minimum detectable activity (MDA's, if applicable) 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.
Page 4 of 11
I + CENEIZ= ATOMICS Final Radiological Survey Report for Area S of the Sorrento Valley West Land Area I Backeround Measurements for Instruments/Detectors Building 13 on GA's main site was used for conducting background measurements with instruments used for the final survey because: (1) there is no history involving radioactive materials or storage of radioactive materials in Building 13, and (2) the various surfaces and construction materials found in Area 5 of Sorrento Valley West Land Area could also be found within and outside of Building 13. Background informnation, 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)
MA2.71 +
A4R65 xt1(dpm/ 1Ocm2) txEx 100 Where:
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):
XxB MDA= -
R (dpni/lOO cn2)
Ex A 100 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 Page 5 of 11
I+ CrNRAL ATOMICS Final Radiological Survey Report for Area S of the Sorrento Valley West Land Area have been established (at the 95% confidence level) and are provided in Table 4 along with the locations where these samples were taken.
Exposure Rate Background Typical exposure rate background for GA's site using a Ludlum Model 19 micro R meter is 12-18 ItRlhr measured at I 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 I onsite at a non-impacted area near Building 15) over a period of 15 months also averaged - 15 JIR/hr (measured at 1 m from the surface). The range of 12-18 pR/hr is typical at the GA site for the external dose rates measured at I meter from the soil surface. Natural background exposure rates on asphalt were 19-21 ILR/hr at contact (within I" of the surface) and 11-19 fIR/hr at 1 meter from the surface as measured with the instrument used in this survey. The natural background levels over concrete were 14-15 p.R/hr at contact (within 1" of the surface) and 14-16 jJR/hr at 1 meter from the surface.
Final Surveys Performed Objectives and Responsibilities The objectives of the final survey plans were: (1) to demonstrate that the average surface contamination levels for each survey unit were below the approved release criteria, (2) to show that the maximum residual activity did not exceed three times the approved release criteria for average surface contamination value in an area up to 100 cm2, (3) to demonstrate soil sample results at the surface were wvell below GA's approved release criteria for unrestricted use, and, (2) that the exposure rate measurements taken in these areas, measured at 1 meter above the surface, were less than 10 ItR/hr above background.
Survey Plans Final Survey Plans were developed based on the previous history of use of the Former Sorrento Valley Area 5 Land Area site, the radionuclides of concern for this area, the potential for contamination, the various types of surfaces encountered and the classification of the various areas. See Appendix A for Final Survey Plan(s) for the Former Sorrento Valley Area 5 site Land Area.
Surveys were taken in accordance with an approved survey plan(s) by qualified Health Physics Technicians having a minimum of three years health physics experience. Soil samples were counted in GA's Health Physics Laboratory which maintains an effective QA program.
Page 6 of 11
I + CEdJRa Aro-Cs Final Radiological Survey Report for Area S of the Sorrento Valley West Land Area I
Every survey taken was documented on a daily basis to a worksheet/drawing showing the approximate locations surveyed/sampled. The documentation included the results of the measurements (including units), the technician's signature, date, instrument(s) used (including the model and serial number of both the ratemeter and detector), calibration due date, %
efficiency, background readings (if applicable) and any other pertinent information.
Soil Sampling Soil samples were collected in approximate locations as indicated on Figure 6. Each of the soil samples taken was approximately 1 kilogram in mass. The samples were properly logged, labeled, tracked and packaged into plastic bags. All debris (i.e., grass, rocks, sticks, asphalt and foreign objects) was removed from each sample. Each soil sample was individually crushed to reduce large lumps, dried, placed into tared marinelli beakers (filled to the top), weighed, sealed and transported to GA's Health Physics Laboratory.
Soil samples were analyzed in GA's Health Physics Laboratory with a Canberra Low Sensitivity Gamma Spectroscopy MCA System using a high purity germanium detector. The system is calibrated using NIST traceable standards and performance checked daily. Soil samples were counted for a minimum of 30 minutes each. A 30 minute count was sufficient to detect the radionuclides of concern at levels below GA's approved soil release criteria.
Survev 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 (IiR/hr) and soil samples taken are provided as follows:
Page 7 of 11
I +
CENERAL ATOMICs Final Radiological Survey Report for Area 5 of the Sorrento Valley West Land Area Comparisons of Site Decommissioning Plan Requirements with Final Surveys Performed for Area 5 of the Sorrento Valley Area Land Area Survey Gridding
- of Fixed
- of Exposure Rate 4/n, Surface
- of Soil Area*
Required Measurements Measurements Scans on Samples
?
Oa, P, or wipes on (VR/hr) asphalt or Taken and concrete or asphalt concrete Analyzed D-Plan*
Yes I every 4m2 or I per 4 m2 or 100% of 4 per Suspect I every 2 m I every 2m accessible I Om x 1 Om grid Affected concrete and Area Minimum= 100 Minimum = 227 asphalt Minimum =20 4
surfaces Final Surveys Yes Total = 109 Total = 241 100% of Total = 39 Suspect lOmx lOm accessible Affected grids Fixed a =54, 241 measurements @lm concrete and 39 surface Areas Fixed,B =27, on grid pattern asphalt (0-6") samples e
Wipes=28 Plus:
surfaces taken on a 5 m 39 measurements at soil triangular grid sample locations and 100% surface scan D-Plan = GA Site Decommissioning Plan The total surface area of this land area is approximately 9,760 ft2 (- 970 m2) as follows:
Asphalt/Cement Trench
-4,284 ft2 (- 398 inm)
Soil 396 ft2('-37m2 )
Soil w/ Vegetation Cover
-5,080 ft2 (- 472 m2 )
Total
- 9,760 ft2 (- 970 m2)
Results of the Final Surveys The final survey results for Area 5 of the Sorrento Valley West Land Area are provided in figures and tables as noted below:
Scanning 100% of the accessible asphalt surfaces and the cement trench (a storm drain trench) were scanned with a, and A, detectors. All a scan results (Figure 3) were at the natural background levels (10-40 cpm). The p scans ranged from 2400 to 3200 cpm which is below the scan MDA of 596 dpm/100 cm2 for the instrument used (Figure 4).
Page 8 of 11
I+ CENERAL ArOMiCS Final Radiological Survey Report for Area 5 of the Sorrento Valley West Land Area Fixed Measurements (a and Wi There were 54 fixed cc measurements and 27 fixed P measurements taken. All a measurements were at the natural background levels (< 20 cpm). The,B results ranged from 862 to 1572 counts per 2 minutes (cp2m). The highest measurement (1572 cp2m) is below the MDA of 213 dpm/100 cm2 and far below the release criteria. The approximate locations and results are shown in Figure 5.
Exposure Rate Scans Exposure rate scans were performed in 100% of the accessible surfaces with a 2"x2" Nal(TI) detector held approximately 1 " from the surface. The exposure rate range was 16 to 26 ILR/hr.
The natural background as measured with the instrument used for this survey (on asphalt surfaces) can range from 19-21 [IR/hr. See Figure 7 for locations and results.
Fixed Exposure Rate Measurements A total of 241 Fixed Exposure Rate measurements were taken at I m from the surface using a microR meter (having a 2"x2" NaI(TI) detector). The highest reading was 22 IiR/hr at the cement trench where radiation levels are expected to be slightly higher naturally due to the geometry of the trench. All radiation levels were far below the 10 [uR/hr above background release criteria. Background readings typically range from I 1-19 jiR/hr on asphalt and concrete surfaces. Figure 8 provides the approximate locations and the results of the survey.
Fixed Exposure Rate Measurements at Soil Sampling locations Thirty-nine (39) Fixed Exposure Rate measurements were taken at I m from the surface at each soil sample location using a 2"x2" NaI(TI) detector. The measurements ranged from 11-14
[uR/hr, which is typical of natural background levels. The results are provided in Table 6. The approximate soil sample locations are shown in Figure 6.
Removable Activity A total of 28 wipe measurements were taken and analyzed for cc and P activity. All samples were <20 dpm/100 cm2. These results are far below the approved release criteria. See Table 5 for results and Figure 5 for appropriate sample locations.
Soil Samples A total of 39 surface soil samples (0"-6") were collected from soil areas and in areas covered with some vegetation. The approximate soil sample locations are shown in Figure 6. The samples were taken based on a 5 m triangular grid.
Page 9 of 11
I +
CENERAL ArOAICr Final Radiological Survey Report for Area 5 of the Sorrento Valley West Land Area I
Gamma spectroscopy results for these soil samples are provided in Table 6 and are summarized below:
Radionuclide Concentrations in pCi/g 137cs 6 0 Co 2 3 8U 235u 2 2 8Th (212Pb) 232Th e 2 Ac)
High 0.75 +/- 0.11 0.15 +/- 0.09 2.27 +/- 1.98 0.30 +/- 0.09 1.93 +/- 0.25 2.05 +/- 0.44 Low ND ND ND ND 0.60 i 0.21 1.02 +/- 0.23 Average
- 0.12
- 0.13
- 1.31
- 0.14 1.74 1.55 (N=39)
Nominal See Table 4 for background soil results, ranges and locations.
Background
Notes:
- 1.
ND means not detected.
- 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 (39) 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.
Soil sample locations are illustrated in Figure 6. Soil sample results are presented in Table 6.
Trace concentrations of the fission product "'Cs were identified in nine (9) out of thirty-nine (39) soil samples. The maximum concentration detected in the soil was 0.75 +/- 0.11 pCi/g (sample number 31 shown on Figure 6). The average Cs-137 concentration in the soil samples was 0.12 pCi/g (not distinguishable from normal background Cs-I 37 concentrations). All of the results were far below the NRC-and State-approved release limit of 15 pCi/g.
The activation product,60Co, was identified in only one (1) out of thirty-nine (39) samples at a concentration of 0.15 +/- 0.09 pCi/g (sample number 22 on Figure 6); a concentration not Page 10 of 11
+ CENERALArMICS Final Radiological Survey Report for Area 5 of the Sorrento Valley West Land Area distinguishable from normal background Cs-60 levels and is far below the NRC-and State-approved release criteria of 8.0 pCi/g.
U-235 and U-238 were not present (as determined by process knowledge and gamma spectroscopy analyses of soil samples). Uranium concentrations were not discernible from natural background levels and were well below the approved release limits for uranium.
Thorium contamination was not present (as determined by process knowledge and gamma spectroscopy analyses of soil samples). All thorium results were at, or near, background levels and well below the release limit of 10 pCi/g.
Confirmatory Survey Following the completion of the Final Survey, an internal Confirmatory Survey was performed by a GA HP technician who did not participate in the final survey. This internal Confirmatory Survey was conducted in accordance with an approved survey plan.
All measurements were in agreement with the final survey results. The confirmatory measurements were at or near natural background levels, and well below the applicable release criteria. See Appendix B for details.
Conclusion Final contamination and radiation surveys, as well as the results of analyses of soil samples, as documented in this report, demonstrate that Area 5 of the Sorrento Valley West Land Area meets the NRC-and State-approved criteria for release to unrestricted use.
Page 11 of 11
-j:-I TTCINTTY'S 1C A
'1' WT A'
V)T ' V'iirV-A fLW' I-%T'I AI 4fT?,7 A "IT rX Y V 17r et Nu>;ides l
e t; i i
l o bl
!_________;___i;____;_
(dpm/lOOcm 2) j-(dp /IlOO crn2) 1(
- - (dpd m/100c 21 U-nat, 235U, 23 8U, & associated decay products 5,000 a 15,000 a 1,000 a Transuranics, 226Ra 228Ra, 23OTh, 228Th, 231Pa, 227Ac, 100 300 20 125J 129_
Th-nat, 2 32 Th, 'Sr, 2 2 3Ra, 2 2 4Ra, 2 3 2U, 1261 1331 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 'Sr and other noted above.
a Where surface contamination by both alpha-and beta/gamma-emitting nuclides exists, the limits established for alpha-and beta/gamma-emitting nuclides should apply independently.
b As used in this table dpm (disintegrations per minute) means the rate of emission by radioactive material as determined by correcting the counts per minute observed by an appropriate detector for background, efficiency, an geometric factors associated with the instrumentation.
c Measurements of average contaminant should not be averaged over more than I square meter. For objects of less surface area, the average should be derived for each such object.
d The maximum contamination level applies to an area of not more than 100 cm'.
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 wvipe 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 mRadlhr at 1 cm2 and 1.0 mRad/hr at I cm2, respectively, measured through not more than 7 milligrams per square centimeter of total absorber.
T-l
Tnlidp 7-RTATE OF CA ACCEPTABLIE ISTJIRACFE CONTAMINATION TFVFIS Nuclides' AveragebeI 1 Naximum bM l
Removableb.W I
(dpm/lOOcm2 )
l (dpmIIOOcm 2) l(dpmlOOcm2)-
U-nat, 235U, 238U, & associated decay 5,000 15,000 1,000 products Transuranics, 226Ra, 228Ra, 2 30h 22 Th 100 300 20 2 3 1Pa. 2 27 Ac, 1251, 1291 Th-nat, 232Th, 90Sr, 223Ra, 224Ra, 232u, 126j 1,000 3,000 200 133j 1311 Betalgamma emitters (nuclides with decay modes other than alpha emission or 5,000 15,000 1,000 spontaneous fission) except 'Sr and other noted above a Where surface contamination by both alpha-and beta/gamma-emitting nuclides exists, the limits established for alpha-and betalgamma-emitting nuclides should apply independently.
b As used in this table dpm (disintegrations per minute) means the rate of emission by radioactive material as determined by correcting the counts per minute observed by an appropriate detector for background, efficiency, an geometric factors associated with the instrumentation.
c Measurements of average contaminant should not be averaged over more than I square meter. For objects of less surface area, the average should be derived for each such object.
d The maximum contamination level applies to an area of not more than I 00 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 I cm2 and 1.0 mrad/hr at I 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 Unrcstricted 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.
T-2
[TABLE 3: LIST OF INSTRUMENTS for Sorrento Valley West, Arca 5 Instrument Detector Range Calibration Due Efficiency
Background
Description (cpm, pR/hr)
Date MDA (434 cm', 100cmp2 D &
50cm2 a detectors only)
Ludlum Ludlum Model 43-37 gas Four Linear Ranges 09103/03 20.98%
10-40 cpm (asphalt)
Active Probe Area = 434 cm2. The detector and rate meter Model 2221 (434cm') proportional 0-500,000 & one Log 20-40 cpm (concrete) are combined and mounted on a roll around cart. The S/N 97287 Alpha detector 50-500,000 instrument features a static-flow system, quick connects, a S/N 083293 (CPM)
Scan MDA - 82 dpm/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 09/26/03 30.17%
2400-2800 cpm (asphalt)
Active Probe Area =434 cm2. Thedetectorand rate meter Model 2221 (434cm2) proportional 0-500,000 & one Log Scan MDA = 596 dpm/100 cmi are combined and mounted on a roll around cart. The S/N 154202 Beta defector 50-500,000 instrument features a static-flow system, quick connects, a S/N 149017 (CPM) 1655-1830 cpm (concrete) portable gas bottle and a means to adjust the height of the Scan MDA - 395 dpm/100 cm2 detector from the floor for optimum performance.
Ludlum Ludlum Model 43-68 Four Linear Ranges 08/13/03 35.82%
14Z8 t 45 cpZmn (asphalt) 100 cm' gas flow proportional counter. The detectorand rate Model 2221 100 cm2 proportional 0-500,000 & one Log MDA-246 dpm/l00cm' meter are combined and mounted on a roll around cart. The SIN 84423 Beta detector 50-500,000 instrument features a static-flow system, quick connects, a S/N 11944 (CPM) 991 +137 cp2m (Concrete) portable gas bottle and a means to adjust the height of the MDA= 213 dpnVl00crm2 detector from the floor for optimum performance.
Ludlum Ludlum Model 43-64 Four Ranges 10/29/03 21,77%
0 -20cpm (All Surfaces)
Active Probe Area -50cm2 Model 12 Alpha Scintilator 0-500,000cpm MDA=209 dpm/l10cm' Used for Alpha surveying and fixed measurements.
S/N 91051 ZnS (Ag)
S/N 94053 Ludlum Ludlum Model 44-10 Four Ranges 10/09/03 N/A 12-18 pR/hr @ I m (soil) 2 inch x 2 inch Nal (TI) scintillator. Used for measuring Model 3 Nal (TI) Scintillator 0-500 pR/hr 11-19 pR/hr at I m (asphalt) external dose rares on the surface and at one meter.
S/N 153311 Gamma Detector 14-16 pR/hr(@ I m on concrete S/N 155594 Ludlum Ludlum Model 44-10 Four Ranges 11/17/03 N/A 12-18 pR/hr@ I m (soil) 2 inchx 2 inchNal (TI) scintillator. Used formeasuring Model 3 Nal (1l) Scintillator 0-500 p.R/hr 11-19 pR/hr at I m (asphalt) external dose rates on the surface and at one meter.
S/N 153551 Gamma Detector 14-16 pR/hr(@ 1 mon concrete SIN 155109 Canberra Low Gas Flow N/A As needed 30%
Varies with Sample Canberra Model 2404 Low Level a/Il gas flow proportional Level aI 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 Germanium Detector Sample Germanium detector.
System T-3
Table4'Gener'a Atom is Gamma Spectroscopy Reults ofB'cko'u'n'd Surfc 'Soil Sampls
Stmbr 24, 2002 137Cs-0 o
8' 22 R9 (232 Tl) 3tl)T Energy Peaks 661.6 keVI'.
1. 1 23 k 1
+
63.3 (92.7), keV 6
~~~~~~~~~~~7.- :
238 ke,:,.:. -.:::.%f::...-::.-:,
'::ke'
______________Samples collected June, 2000 Re-analyzed November, 2001 X-l ND1 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+/-40.47 3.78+/-0.78 ND (0.18+/-40.13)
X-5 ND ND 1.52 +/- 0.29 2.83 +/- 0.70 4.35 +/- 0.99 ND (0.20 2
0.15)
X-6 ND ND 1.14+/-0.32 1.12+/-40.26 2.25+/-40.58 ND (0.09+/-0.05)
X-7 0.11+/-40.07 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 (0.26+/-0.14)
X-9 ND ND 0.61d +/-0.15 1.59+/-0.42 2.20+/-0.57 ND ND X-10 0.09+/-0.06 ND 1.59+/-0.26 1.39+/-40.36 2.98+/-0.61 0.75+/-1.22 (0.13+/-0.07)
Samples collected and analyzed September, 2002 X-ll 0.23+/-0.07 ND 1.37+/-0.29 1.71 +0.37 3.07+0.66 1.13+ 1.30 (0.25+/- 0.11)
X-12 0.31 +0.08 ND 0.50+/- 0.08 0.65+/-0.18 1.14+0.26 ND (0.11 +0.07)
X-13 ND ND 0.95+/-0.20 1.13+/-0.23 2.08 0.43 1.290.99 (0.14+/-0.05)
ND = Energy peak not identified T-4
Tal 4 (c ^on-WP tinued) : Gene -
{fraDf{sls Aois Gam
- pie
.Tablc 4. (continued):..General~tomics.Gam Spectroscopy Rcsults of BackgroundSurfcc Soil Sam
~.-
747)'
2002 137v-it h'-'
8Ra
~238Th)
,-En'ergyPCaks.-'
- b.
.. A661.6V 1173 kcV 238 911 k.V
'.22
-3(92.
keV 144 (186) k V w
I Q'2,,
- nr (2'
- 6. 3 mple ~
~
~
~
~
~
~
~
(p~~~~~i/g) -~~~~~~R"slt +/-'2ar-`30 Mlinu...e C~oiin&-
X-14 ND ND 1.42 +/- 0.19 1.59+/-0.29 3.01 +/-0.48 0.67+0.71 (0.11 +/- 0.05)
X-15 ND ND 0.37 +/- 0.09 0.56 +/- 0.16 0.92 +/- 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 +/- 0.08)
X-26 ND ND 1.81 +/- 0.24 1.41 +/- 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+/-0.06)
X-30 ND ND 1.90+/-0.22 1.88+/-0.33 3.79 +/- 0.55 2.67 +/- 1.79 (0.35+/-0.11)
T-5
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 Sorrcnto 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 -
'/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 I 1/2 miles from Building 37 (collected on the hillside).
X8 Vista Sorrento Parkway, - 1/2 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).
X11 Creek Road (North County).
X12 Canyon de Oro (North County).
X13 Palomar (North E County).
X14 Deer Springs Rd. (North County).
X 15 Rice Canyon Rd. (North County).
X1 6 Las Pulgas Rd. (North County).
X17 Boderfield Park (South W County).
X18 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
Table 5: Sorrento Valley WVest Land Area, Area 5 Wipe Survey Results Sample Number a Activity in dpm/l 00cm2 1 Activity in dpm/I OOcm 2 I
<20
<20 2
<20
<20 3
<20
<20 4
<20
<20 5
<20
<20 6
<20
<20 7
<20
<20 8
<20
<20 9
<20
<20 10
<20
<20 11
<20
<20 12
<20
<20 13
<20
<20 14
<20
<20 15
<20
<20 16
<20
<20 17
<20
<20 18
<20
<20 19
<20
<20 20
<20
<20 21
<20
<20 22
<20
<20 23
<20
<20 24
<20
<20 25
<20
<20 26
<20
<20 27
<20
<20 28
<20
<20 29
<20
<20 T-7
Tabl c6:~
-GmaSpectoscoyReuts of Sorrento ValleyWestAre~a-5tand-Are, olape 137s
-60C 22b
~
2 Ra 2f2 Tb) 1 Al Tb ---
`::
3 3
apl nftcry Peaks
- 66.
e 13c 28kV->IkV
~
2 ~b' 3 Th): -63.3'(91.7) ~keVY,
- (144) 186 k6V..~,
locaton,:,
.- "Th)
Eosr
-~~~~~~~~~~~
~~~~~~Rate 1m '
am-pe-I-:
Radion'uc~ide -Con-cen-trafions, (1 Cig, W
aueus etasntd),
-Backgrouds' Not Sibtracekd; SVB-l ND ND 0.86 +/-0.15 1.05+/-+0.23 1.91 +/- 0.38 ND 0.12 +0.05 12 SVB-2 ND ND 1.44+/-+0.30 1.41 +/- 0.31 2.85 +/-0.61 ND 0.22 +0.10 12 SVI3-3 ND ND 1.35 +/-0.20 1.10 +0.26 2.45 +/-0.46 1.48+/-+1.44 0.13 +/-0.06 12 SVB-4 ND ND 1.23 +/-0.16 1.60+/-+0.30 2.83 +/-0.46 ND 0.10 +/-0.07 13 SVB-5 ND ND 1.39+/-+0.18 1.23 +/-0.31 2.62+/-+0.49 0.34 +/-1.06 0.16 +/-0.07 12 SVB-6 0.11 +/- 0.07 ND 0.73+/-+0.23 1.02 +/-0.23 1.75 +/-0.46 ND 0.06+/-+0.04 12 SVB-7 0.06+/-+0.05 ND 1.48+/-+0.28 1.42+/-+0.31 2.90+/-+0.59 0.92+/-+ 1.15 0.16+/-+0.09 1 1 SVB-8 ND ND 1.62 +/-0.3 0 1.98 +/-0.40 3.60+/-0.70 ND 0.08 +/-0.06 12 SVB-9 ND ND 1.48 +/-0.28 1.74+/-+0.35 3.22+/-0.63 ND 0.08+/-+0.06 1 2 SVB3-10 ND ND 1.42+/-+0.31 1.37+/-+0.34 2.79+/-+0.65 1.11 +/- 1.28 0.23+/-:-0.08 1 3 SVB-11 ND ND 1.35+/-I0.25 1.56+/-4-0.32 2.91 +/- 0.57 1.57 +/- 1.51 0.3 0+/-0.09 1 1 SVB-12 ND ND 1.75 +/-0.21 1.37 +/-0.27 3.12 +/-0.48 ND
- 0. 12+/-0.06 14 SVB-13 ND ND 1.71 +/-0.22 2.03 +/-0.36 3.74 +/-0.58 ND 0.14+/-0.06 12 SVB-14 ND ND 1.25+/---0. 16 1.13 +/-0.29 2.38 +/-0.45 1.52 +/- 1.34 0.13+/-0.06 1 1 SVB-15 ND ND 1.51 +/- 0.19 1.45 +/--0.30 2.96+/-+0.49 ND
- 0. 12+/-0.06 12 SVB-16 ND ND 1.52+/-+0.28 1.42 +/-0.29 2.94 +/-0.57
- 1. 18+/-4-1.25 0.18+/-0.08 12 SVB-17_
ND ND 1.54+/-+0.28 1.64 +/-0.30 3.18+/-+0.58 ND 0.17+/-0.07 12 T-8
' Table 6: GammaSpectroscop Rit r
S amle
~T bl'6
`.',-
,'A'.','.'
Enrgy.Paks"
- ^
61' 6
'c
>'i3ke-I:>
e':
I.-'..................~1.e:"'
- ', '0C j;;;,'
'21p' I......:^'2,') '~':
kcV S 1173 t
eV C o
1k
.. Saifle Energy Peaks 661.6 keV 238 911 ke,:,~,;eV'- 2 8TVI Th' 63.3 (92.7)j ke,.:; (144),186 keV;...
"location
,c) -.,.
Ex'o u r I
.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~k o ur.
SVB-18 ND l
ND l0.60+/-0.21 l 1.12+/-0.22 l1.72+/-0.43 l
ND l0.06+/-40.03 13 SVB-I9 ND 7
ND l1.31+/-0.17 l 1.57+/-0.33 l2.88+/-0.50 l 2.27+/-1.98 l0.19+/-0.09 13 SVB-20 ND ND 1.36i0.17 T 1.45+/-40.31 l2.81 +/-0.48 l 1.14+/-1.10 l0.15+/-0.09 13 SVB-21 ND ND 1.59+/-0.20 1.57+/-0.30 3.16+/-40.50 ND 0.14+/-0.06 14 SVB-22 ND 0.15+/-40.09 1.58+/-40.30 1.62+/-0.33 3.20+/-0.63 1.80+/- 1.67 0.10+/-0.06 13 SVB-23 ND ND 1.42+/-0.18 1.72+/-0.32 3.14+/-0.50 ND 0.13+/-0.06 13 SVB-24 ND ND 1.54+/-0.22 1.41+/-0.28 2.95+/-0.50 ND 0.12+/-0.06 14 SVB-25 ND ND 1.77+/-0.27 1.68+/-40.37 3.45+/-0.64 ND ND 12 SVB-26 ND ND 1.79 +/-0.32 2.05 +/-0.44 3.84 +/-0.76 0.97 +/- 1.08 0.14 +/-0.06 12 SVB-27 ND ND 1.48+/-0.19 1.37+/-0.32 2.85+/- 0.51 ND 0.12+/-0.07 12 SVB-28 0.11+/-0.08 ND 1.93+/-0.25 1.30+/-0.32 3.23+/-0.57 ND 0.16+/-0.06 12 SVB-29 ND ND 1.49+/- 0.27 1.45+/-0.32 2.94+0.59 0.90+/- 1.18 0.11 +/- 0.05 12 SVB-30 0.17+/-0.04 ND 1.56+/-0.32 1.71+/-0.36 3.27+/- 0.68 ND 0.15+/-0.07 13 SVB-31 0.75+/-0.11 ND 1.77+/-0.24 1.92+/- 0.33 3.69 4 0.57 0.85+/-0.91 0.14+/-0.06 12 SVB-32 0.17+/- 0.08 ND 1.59+/-0.28 1.60+/-0.33 3.19+/- 0.61 ND 0.10+/-0.07 13 SVB-33 ND ND 1.57+/-0.28 1.86+0.32 3.43 +/- 0.60 1.71 N 1.59 0.13+/-0.06 13 SVB-34 ND ND 1.48+/-0.19 1.63+/-0.33 3.11 +/-0.52 ND 0.23+/-0.07 13 T-9
'.:Table 6:
GaSpectrospy ResIlts' Srnto Vl WesAt Area5Land: Area pS i
.,~~~~~~
C...
i' te.'.'Z-';
133 C
F CO X Zs k
S ample
.Energ'yPak.
,61.6V i73keV
-'238 8keV 911'ke
,)63.33(927) ke n(144)!18 keV.
location,'
£.
(' ~".
- -(.Pb Ac)
(,2 Th)Epr S loncenirntions (i/g-Rcsiiit +/- 2a 30 Aiiute Couits (
Back'roinds Not Stibtrdted'
~-<-
i t-iCC~
t ' ~d-grac
'r';,!;.-,
SVB-35 ND ND 1.74 I 0.35 1.63 + 0.35 3.37 0.70 1.22 + 1.50 0.14 0.08 12 SVB-36 0.20 + 0.06 ND 1.69+/- 0.33 1.78 +/- 0.33 3.47 0.66 1.06 + 1.30 0.21 +/-0.07 12 SVB-37 ND ND 1.50 0.28 1.62 +/- 0.30 3.12 + 0.58 1.26 +/- 1.34 0.13 0.06 12 SVB-38 0.07 +/- 0.05 ND 1.78 0.26 1.84 I 0.38 3.62 + 0.64 1.05 +/- 1.31 0.18 0.10 12 SVB-39 0.01 +/- 0.03 ND 1.71 +/- 0.21 1.84+/- 0.35 3.55+/- 0.56 ND 0.15 0.09 13 Notes:
1.
2.
ND mcans not detected.
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 kcV peak)
Co-60 = 0.13 pCi/g (1173 kcV peak)
Th-228 = 0.17 pCilg (238 keV peak)
Th-232 = 0.38 pCi/g (911 keV peak)
T-10
Building Numbers Names Figure 1A: GA's Main Site and Sorrento Valley Site 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 29 Building 29-2 Building 30 Building 31 Building 31-2 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 39-1 Building 42 Building 45 Building 63 Building 64 Building 65 Building 66 Building 66 Administration Science Laboratories A, B, C Cafeteria Office/Lab Building Office Building/Health Physics Technical Office Building Technical Office East Technical Office East Swimming Pool Building TRIGA Building Inertial Fusion Development Building Former Hot Cell Site Former Liquid Waste Processing Buildin Space Power Building Office Building Landscaper's Building Office/Lab Building (Former LINAC Complex)
Storage/Nuclear Calibration ECF Critical Building S(
ICF Lab Building Vail ICF Office Building Painters Building Fusion DIII-D Building Fusion DIII-D Capacitor Building Fusion DIII-D Lab Building Fusion DIII-D Storage Building Test Tower Building Facilities (Shipping & Receiving)
Experimental Building Sorrento Valley Building A Storage Building Laboratory Building (QA)
Machine Shop 3550 Dunhill St.
11030 Roselle St 3520 Dunhill St.
/ //
31-3510 Dunhill St.
o
,//
N A
W<E VS ley West Area 5 SITE OPEN SPACE SITE 0.
I-rat I.-
0 za LOTS UCSD
- FENCING
~~ PROPERTY LINE 0 250 500 750 1000 SCALE SCALE IN FEET 10/22/03
Date: 03/14/03 Figure I B: Sorrento Valley Site Land Areas SORRENTO VALLEY AREA I WEST AREA 2 OF SORRENTO VALLEY WEST N
NORTH WEST AREA 3 OF AREA 4 SORRENTO VALLEY CENTRAL BUILDING 42 SVA BUILDING 37 SOUTH SOUTH TEST TOWER LAND SORRENTO VALLEY EAST Sc.. vn Feet 0
200 400
Figure 2: Sorrento Valley West Land Area, Area 5 I
Concrete Storage Bunker addressed in separate
/- "
report D
1
Figure 6: Sorrento Valley West Land Area, Area 5, Soil Sample locations
~~~A T
\\
iq bongeation cAn
\\
t
,h X1 a> sphab a
o ha
\\
if)
A) 9 bu~~~~nker>/
- 100,
'00,~~~~~3,
,t~'
\\
'(1N
\\ \\~
\\)
\\
D a n ok swererion
/
\\
,~~~~~~~~~~~~~~\\
1
General Atomics' Final Radiological Survey Report For Sorrento Valley West Land Area, Area 5 Appendix A Sorrento Valley West Land Area, Area 5 Final Survey Plan
Page 1 of 4 April 15, 2003 Prepared By: W. T. LaBontnt/
Approved By:
At(Q A'
L. Q. Gonzales Final Radiological Survey Plan for Sorrento Valley West, Area 5. Land Area Scope This Final Survey Plan is for Sorrento Valley West, Area 5, Land Area. This parcel of land is located in the GA Sorrento Valley Site. This Land Area contains a.concrete shielded bunker previously used to store high levels of radioactive material awaiting packaging or shipment to a licensed facility for disposal. The remainder of this area is open land, portions of which are paved with asphalt. There are no sewer systems or storm drain piping systems that traverse this area.
The total surface area of this land area is approximately 5,120 ft2 (- 580 in2). The floor space of the storage bunker is approximately 225 ft2(- 21 m2). See Figure 1.
History and Classification This portion of the Sorrento Valley West Land areas was previously included with Sorrento Valley West, Area 4,Land Area. During the final survey, elevated activity levels were found in the soil, on asphalt, and interior portions of the storage bunker within this area. For expediency reasons, Sorrento Valley West, Area 4, Land Area was divided into two survey areas. This portion was renamed Sorrento Valley West, Area 5, Land Area and extensive decontamination operations were performed.
Due to the elevated activity levels found in this area, the entire area is classified as a Suspect Affected Area for survey purposes.
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 pR/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 SVSW survey plan.wpd
Page 2 of 4 Technician experience. The survey and final report documenting the survey will be performed by GA's Health Physics group.
Release Criteria (per GA Site Decommissionine 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 cm, averaged over a 1 m2 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 1 m above the surface, is 10 1iR/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 II 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.
SVSWV survey plan.wpd
Page 3 of 4 Exposure Rate Measurements
> 25 [LR/hr at surface
> 20 JIR/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 survey plan.wpd
Page 4 of 4 Final Radiological Surveys Plahned for the Sorrento Valley West, Area 5, Land Area Suspect Affected Area, Suspect Affected Area, Type of Survey/Activity Open Land Area Storage Bunker Gridding Required?
Yes, IOxlO m grids Yes, 2mx 2 m grids.
Asphalt or Concrete Surfaces (1) 100 % on land areas.
100 % on all surfaces (internal and (Scan w1434 crn2 alpha probe).
external) up to 2m from the floor.
10% of surface greater than 2m high.
Asphalt or Concrete Surfaces (1) 100 % on land areas.
100 % on all surfaces (internal and (Scan w/ 434 cram beta probe).
external) up to 2m from the floor.
10% of surface greater than 2m high.
Minimum number of I measurement per 4 m2, or, I measurement per 4 rn2, or, Measurements (2) (3) 1 measurement every -2 m I measurement every -2 m Alternate between (1) a wipe, (2) an Alternate between (1) a wipe, (2) an alpha fixed measurement and (3) a alpha fixed measurement and (3) a beta fixed and alpha fixed beta fixed and alpha fixed measurement on all asphalt or measurement concrete surfaces. Total number of measurements on land = 80 (based on 320 in2 asphalt area).
lIR/hr Readings, Scans 100% scan on all surfaces, detector 100% scan on all surfaces (internal held -1 " from surface and external), detector held -1 " from surface below 2m from floor, 10%
above 2m.
[LR/hr Readings I every 2m I every 2m
@ I m from surface Soil Samples Based on a 5 meter triangular grid NA system. See Figure 2 l
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 f3 activity.
A "measurement" is either (1) a "fixed" radiation measurement representing total activity or (2) a wipe (removable activity).
(3)
SVSW survey plan.wpd
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General Atomics' Final Radiological Survey Report For Sorrento Valley West Land Area, Area 5 Appendix B Sorrento Valley West Land Area, Area 5 Confirmatory Survey
Appendix B Sorrento Val1levi West Land Area. Area 5 GA Confirmatory Survey Results Description Following the completion of the Sorrento Valley West Land Area, Area 5 Final Survey, a Confirmatory Survey was performed by a Health Physics Technician in accordance with an approved Survey Plan (see Attachment 1). Sorrento Valley West Land Area, Area 5 is illustrated in Figure 1.
The purpose of this survey was to confirm that the Final Survey was effective in identifying the radiological conditions of the area and confirming that the radiation levels meet the NRC-and State-approved release criteria for unrestricted use.
Results
- 1.
Six (6) surface (0-6") soil samples of the unpaved surface south and east of the shielded bunker. See Figure 2 for approximate locations and Table 1 for gamma spectroscopy results. The results contained in Table I are summarized below:
ins p~i/g 9 iU-235-I 35 IT in p~~~~~~~~~~~~~~~~~~~~~~~ilg
~~~~~~~~~~~~~~~~~~~~~~~
in p~~~~~~~~~~~~~~~~~~
1ql nP;1 High 0.04 *0.06
<0.16 1.00* 1.26 0.18 0.10 1.76 +/- 0.22 1.75 + 0.39
.; Low. -- *
<0.13
<0.16
<1.58 0.11 0.09 1.07*0.18 1.46*0.33 Average s0.13 s
0.16 s
1.58 s
0.14 1.42 1.53
- '+< N4~6)
Notes:
- 1.
Less than (<) values indicate that the radionuclide was not detected so the average minimum detectable activity (MDA) was used:
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 = 0.16 pCi/g (1173 keV peak)
Th-228 = 0.21 pCi/g (238 keV peak)
Th-232 = 0.43 pCi/g (911 keV peak)
- 2.
The sum of fractions for any sample was far less than 1.0.
- 3.
All results were far less than the approved release criteria.
- 4.
The average is based on all positive results and the MDA value when activity was not detected.
I of 2
U-238, U-235, Th-228, Th232 were not discernible from natural background.
Cs-137 was detected in one (1) sample. The highest concentration was 0.04 + 0.06 pCi/g which is far below the approved release criteria of 15 pCi/g and not distinguishable from background concentrations in soil.
- 2.
Six (6) fixed a measurements were taken on the asphalt surface. The highest measurement was <20 cpm. The natural background was 0-20 cpm. See Figure 2 for locations and results.
- 3.
Five (5) fixed P measurements were taken on the asphalt surface using a 100 cm2 gas flow proportional detector. The highest measurement was 1365 cp2m, which is less than the Minimum Detectable Activity (MDA) of 286 dpm/100 cm2.
Background levels were 1428 cp2m (MDA=286 dpmi/100 cm2). See Figure 2 for approximate locations and results.
- 4.
Wipe surveys for removable surface contamination were taken in four (4) locations and analyzed for alpha and beta activity sing a low-level alpha beta gas flow proportional counting system. All results were <20 dpm/I 00 cm2 and well below the release criteria.
See Figure 2 for locations and Table 2 for results.
- 5.
About 10% of the asphalt surface was scanned with a 434 cm2 gas flow proportional detector for a and P activity. The a measurements ranged from 20 to 40 cpm, which is the natural background level as measured with the instrument used on this survey. The,
activity ranged from 1900 to 2600 cpm, the background measurement, taken in a non-impacted area, was 2400 to 2800 cpm. See Figure 3 for locations and results.
- 6.
Exposure rate scans were performed on 10% of the asphalt surface with a 2" x 2" NaI(TI) detector held within 1 " of the surface. The range for the measurements at 1 " from the surface was 19 to 23 ipR/hr. See Figure 4 for locations and results.
- 7.
Sixteen (16) fixed exposure rate measurements were taken at im from the surface. The range was 19 to 23 IIR/hr. See Figure 4 for locations and results.
- 8.
Exposure rate measurements were taken at contact with, and at 1 meter from, each of the six (6) soil sample locations. The highest contact measurement was 24 iR/hr, the highest measurement at 1 meter was 21 [iR/hr. See Figure 4.
Conclusion All of the Confirmatory Survey results indicated that activity levels on the Sorrento Valley West land area, area 5, are not discernible from natural background levels, which agrees with the Final Survey results.
2of2
-)
Table 1: 'SorrentoValey West Land Area r' a
t5 Gamma SOeetoscOy Results of Soil Sam es.
s C....::ollded July 0 03:
Radinlide'Concentration (pCi/g) -Results§ 2&-
ground notSubtrted -30inute counts
-Sanile ID
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tm Q
s oa'62kYpa 1328kVpa "T) 0 hru
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il,;
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' 2P911 keVp Ia pea e
2 T38 kk ak kV Vpeak
~~~0 ~
~ ~ ~ ~ ~ (
(22fV Ac22________ [
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X
]
i X M.(2 Rp
-c ke- :p-SVWLA -A ND ND 1.24 4* 0.17 1.46
- 0.33 2.71 *0.50 ND (0.11 *0.07)
SVWLA-B ND ND 1.54+/- 0.21 1.54 + 0.30 3.09* 0.52 ND (0.18 0.08)
SVWLA-C ND ND 1.07*0.18 1.75 + 0.39 2.82* 0.57 1.00 + 1.26 (0.18 0.10)
SVWLA-D ND ND 1.33 t0.35 1.32 + 0.29 2.65
- 0.63 ND (0.11 0.06)
SVWLA -E 0.04* 0.06 ND 1.76 I 0.22 1.67 +0.34 3.42 + 0.55 ND (0.15 0.06)
SVWLA-F ND ND 1.58*+ 0.21 1.52
- 0.36 3.10
- 0.57 0.99
- 1.42 (0.11 0.09)
Notes:
- 1.
ND = Not Detected, energy peak not identified.
- 2.
Concentration in parenthesis denotes alternate energy peak, in parenthesis, used.
- 3.
Average Minimum Detectable Activities (MDAs):
U-238 = 1.37 pCi/g (63 keV peak)
Co-60 = 0.13 pCi/g (1173 keV peak)
U-235 = 0.12 pCi/g (186 keV peak)
Th-228 = 0.17 pCi/g (238 keV peak)
Cs-137= 0.10 pCi/g (662 keV peak)
Th-232 = 0.38 pCi/g (911 keV peak)
Table 2: SorrentoValleyWest Land' Area, rea 5 r
rvey ie S:rey Result's'.
Sam-'pie.Number,',
- c. ActivityindpmI1 0Acti' 0
l:
ity ifn dpmll00c l1,t.._'
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<20
<20 2
~~~~~~~~<20
<20 3
~~~~~~~~<20
<20
<20 20___ _
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I Figure 1: Sorrento Valley West Land Area, Area 5
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Figure 2: Fixed Alpha and Beta Measurements and Wipe Locations Confirmatory Radiological Survey for Sorrento Valley West, Land Area, Area 5, Instruments Model I Ludlum 12 1 Ludlumn 2221 1 Lud
/
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B vegetation 4--
C vegetation 1224 13 asphalt
<20a
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<20 D
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Notes:
- 1.
m Denotes wipe number and location. Wpe results are provided in Table 2.
- 2. ## a Denotes fixed alpha measurement in cpm.
- 3. #### p Denotes fixed beta measurement in cp2m.
1 Survey Conducted by: G Sayer Dates: 07-30-03 to 08-06-03
Figure 3: Alpha and Beta Surface Scan Locations and Results Confirmatory Radiological Survey for Sorrento Valley West, Land Area, Area 6, Ludlum 2221 84459 02-02-04 434 cm' a 086215 21.58 10-40 D
Notes:
- 1. 10% of accessible asphalt surface scanned.
- 2. ##-## a Denotes alpha scan in cpm.
- 3. ####
p Denotes beta scan in cpm.
1 Survey Conducted by: G Sayer Dates: 07-31-03 and 08-06-03
Figure 4: Exposure Rate Fixed Measurements and Scans Confirmatory Radiological Survey for Sorrento Valley West, Land Area, Area 5,
-I I
Notes:
- 1. All readings are in pR/hr.
- 2. ## Denotes fixed measurement taken at - 1 surface.
1
- 3. -+- #I#
-*- Denotes scan range. 10% of accessible asphalt surface scanned.
- 4. X = microR/hr reading on contact At soil s location XX = microR/hr reading at 1 m sampe Survey Conducted by: G Sayer Date: 07-30-03
General Atomics' Final Radiological Survey Report For Sorrento Valley West Land Area, Area 5 to Appendix B Sorrento Valley West Land Area, Area 5 Confirmatory Survey Plan
Page 1 of3 July 29, 2003 Prepared By: W. T. LaBonte Approved By:
VTA -
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L. Q. Gonzales Confirmatory Radiological Survey Plan for Sorrento Valley West Land Area, Area 5 This Confirmatory Survey Plan is for Sorrento ValleyWest Land Area, Area 5. This parcel of land is located in the GA Sorrento Valley Site. This land area contains a shielded bunker. The final survey was completed and a release request for the bunker was submitted earlier this year. This bunker is therefore not included in this survey plan. This confiratory survey is for the open land areas surrounding this bunker, most of which is paved with aphalt, and the vegetation covered hillsides within the boundary of this land area. The total surface area of this land area is approximately 5,120 ft2
(- 580 m2), the asphalt paved area is approximately 4090 ft2 (- 380 M2 ). See Figure 1.
Histonr and Classification This potion of the Sorrento Valley West Land Area was previously included in the Sorrento Valley West, Area 4, Land Area. During the final survey in this potion of land, elevated activity levels were found in the soil, on the asphalt paving and within the bunker. For expediency reasons, this portion of land was redefined as area 5. The final survey for Area 4 was completed, and the release request was submitted. Earlier this year, decontamination of the bunker interior was performed and a final survey was completed. No activity above background was found inside, or outside, of the bunker. A separate release request was submitted for the unconditional release of this bunker in June 2003. Prior to the submittal of this release request, a representative from the NRC performed an "in-progress" survey of the bunker and agreed that residual activity in this bunker is at background levels.
Decontamination activity was completed on the elevated activity areas adjacent to the bunker (western side) and a final survey was completed on the open land areas. No activity above the release criteria was found.
This entire land area is classified as a Suspect Affected Area for survey purposes.
Survev Obiectives and Responsibility The purpose of performing a confirmatory survey is to verify the radiological conditions identified during the Final Radiological Survey.
W:\\SVSW Area 5confirm.wpd
Page 2 of 3 Release Criteria (per GA Site Decommissionine Plan)
Concrete/Asphalt Surface Release Criteria The NRC release criteria for mixed fission and activation products is:
1,000 dpm /100 cm, averaged over a I m' area 3,000 dpm /100 cm2, total, maximum in a 100 cm2 area 200 dpm/100 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 cm, removable activity Exposure Rate Measurements The guideline value for exposure rates measured at 1 m above the surface, is 10 jlR/hr above background.
Alert Levels Alpha Alert Values If the following "alert levels" are exceeded, notify HP Management so an evaluation can be performed and to evaluate if decontamination is required.
> 100 cpm alpha using the large area (434 cm2) probe (check area with a hand-held alpha meter).
> 60 cpm using a 50 cm2 hand-held alpha probe (- 600 dpm/100 cm2)
Beta Monitorin'
>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,R/hr at surface
> 20,R/hr at 1 m Minimum Confirmatonr Survey Reguirements The minimum survey requirements for this confirmatory survey is as follows:
WASVSW Area Sconfinm.wpd
Page 3 of 3 Type of Survey/Activity Suspect Affected Area Gridding Required?
Yes, lOx lo m grids.
Asphalt or Concrete Surfaces 10 %
(Scan w/ 434 cm2 alpha probe).
Asphalt or Concrete Surfaces 10 %
(Scan wI 434 cm: beta probe).
Minimum number of 1 measurement per 40m2, or, Measurements I measurement every -20m Alternate between (I) 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 = 10 (based on 380 m2 asphalt area).
[iR/hr Readings, Scans 10% scan on asphalt/concrete surfaces, detector held
-I " from surface l.LR/hr Readings I every 20m l@ Im from surface Soil Samples I in each grid (see Figure I for grids)
Documentation Every survey conducted must be documented on a daily basis on a drawing showing the approximate locations surveyed. Include the results (including units), the technicians signature, date, instrument(s) used (including model and serial number of both the ratemeter and the detector), calibration due date,
% efficiency, background readings (if applicable) and any other applicable information.
W.\\SVSW Area 5confirm.wpd
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vegetation \\vegetap on vegetation X
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