ML030220088
| ML030220088 | |
| Person / Time | |
|---|---|
| Site: | 07000734 |
| Issue date: | 01/14/2003 |
| 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-3558 | |
| Download: ML030220088 (34) | |
Text
"?0 -73 13
+ GENERAL ATOMICS January 14, 2003 696/CAL-3558 VIA EXPRESS DELIVERY SERVICE Ms. Mary Adams (in Duplicate)
Fuel Cycle Licensing, Branch/Section 1 U.S. Nuclear Regulatory Commission Two White Flint North, Mail Stop T-8A33 11557 Rockville Pike Rockville, MD 20852-2738
Subject:
Docket No.70-734; SNM-696: Request to Release Certain Portions of General Atomics' Facility to Unrestricted Use and Delete them from its License: Namely, Torrey Pines North Hillside (TPNH) Land Area-Suspect Affected Area of Section C 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 Certain Portions of General Atomics' Facilityto Unrestricted Use and Delete them from its License: Namely, Namely, Torrey Pines North Hillside (TPNH)
Land Area - Suspect Affected Area of Section C
References:
- 1) Keith Asmussen Letter dated August 30,2002 (696/CAL-3508), "Request to Release Certain Portions of General Atomics' Facility to Unrestricted Use and Delete them from its License: Namely, Torrey Pines North Hillside (TPNH)Land Area - Sections A, B, D and Unaffected Areas of Section C."
- 2) Amendment No. 75 to NRC License SNM-696, dated December 9,2002; releases the TRIGA Trailer Land Area and Portions of Torrey Pines North Hillside (Sections A, B, D and Unaffected Area of Section C) to Unrestricted Use
Dear Ms. Adams and Ms. Kwok:
As you are aware, General Atomics (GA) is continuing its efforts to decommission and decontaminate, as appropriate, selected facilities and land areas on its site in support of obtaining their release to unrestricted use and their deletion from GA's radioactive "k Yý-5O 3550 GENERAL ATOMICS COURT, SAN DIEGO, CA 92121-1122 PO BOX 85608, SAN DIEGO, CA 92186-5608 (858) 455-3000
Ms. Mary Adams, NRC / Ms. Sudana Kwok/State 6961CAL-3558 January 14, 2003 Page 2 material licenses. GA recently completed an extensive project on a portion of the steep hillside north and northwest of GA's Main site. This area is referred to as the "Torrey Pines North Hillside (TPNH) Land Area."
The TPNH Land Area is essentially the strip of land that lies between the GA site boundary and the GA "Controlled Area" fence on the north and northwest sides of GA's Main Site (Torrey Pines Mesa). This land area consists of steep hillsides located between GA's main site mesa and a dedicated open space area in which any development is prohibited by land zoning restrictions. It is extremely unlikely that GA, or anyone in the future, would be allowed to develop or build on this land area.
To facilitate the logistics of conducting the radiological surveys on the TPNH land area, it was sub-divided into four sections identified as Sections A, B, C, and D. These sections were further sub-divided into "unaffected" areas and "suspect affected" areas. The subject of this release request is a small land area referred to as the "Suspect Affected Area of Section C," (see attached Figure 1). This area was excluded from a prior release request (Ref. 1) which addressed the rest of the TPNH Land Area; which has since been released by the NRC (Ref. 2).
The Suspect Affected Area of Section C lies between the west boundary of the former Hot Cell Site and GA's northwest site boundary. The total land area included in this request measures approximately 9,100 ft2 (-846 M2). There are no paved surfaces, buildings or sewer systems within this land area.
Elevated radiation levels and elevated Cs-1 37 and Co-60 concentrations measured in some of the soil samples taken in the Suspect Affected Area of Section C were noted during the final survey. Although the levels were below the NRC-and State-approved soil release criteria specified in GA's Site Decommissioning Plan, GA decided to remove soil from these areas. A total of 1,200 ft3 (- 33.3 M3) of soil was removed and disposed of as low level radioactive waste.
Soil samples taken after decontamination efforts were complete, showed residual concentrations at levels -20% or less of the corresponding approved release criteria. Furthermore, considering the location of the contaminated soil (a steep, uninhabitable, unoccupied, normally inaccessible hillside), GA believes that the levels achieved after decontamination were As Low As Reasonably Achievable (ALARA).
Enclosed is GA's report titled "General Atomics' Final Radiological Survey Report for the Torrey Pines North Hillside (TPNH) Land Area/Section C, Suspect Affected Area,"
dated January2003. This report documents the results of GA's radiological measurements, surveys, and soil sampling and analyses which demonstrate that this land area meets the State-and NRC-approved criteria for release to unrestricted use.
Ms. Mary Adams, NRC / Ms. Sudana Kwok/State 696/CAL-3558 January 14, 2003 Page 3 Accordingly, GA hereby requests both the U.S. Nuclear Regulatory Commission (NRC) and the State of California Department of Health Services' Radiologic Health Branch (State) to release the suspect affected area of section C of the Torrey Pines North Hillside Land Area, as described in the enclosed final survey report, to unrestricted use and to delete it from GA's NRC and State radioactive material licenses, respectively.
It is GA's understanding that the NRC is the lead agency in coordinating this release request, including conducting regulatory agency confirmatory surveys, as are deemed appropriate; the results of which will be made available to the State.
If you should have any questions regarding this request or the enclosed report, please 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, Keith E. Asmussen, Ph.D., Director Licensing, Safety and Nuclear Compliance
Attachment:
Figure 1: Torrey Pines (Main) Site Land Areas.
Enclosure:
GA report titled: "General Atomics' Final Radiological Survey Report for Torrey Pines North Hillside (TPNH) Land Area/Section C, Suspect Affected Area," dated January 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
Attachment to GA's Letter No. 696/CAL-3558, dated January 14, 2003 Figure 1: Torrey Pines (Main) Site Land Areas TORREY PINES NORTH HILLSIDE SUSPECT AFFECTED AREA of SECTION "C" Bunker Yard Bld 21/27 HOT CELL LAND I tP^Af%
Utility Pad
/
-Il, 11i'Vl,"-
Bldg.
TORREY PINES NORTHEAST Yard TORREY PINES Reactors
& Land TORREY PINES EAST TFF TORREY PINES SOUTH S At
GENERAL ATOMICS' FINAL RADIOLOGICAL SURVEY REPORT for the Torrey Pines North Hillside (TPNH) Land Area Section C, Suspect Affected Area Prepared By: William LaBonte, Joseph Sullivan and Laura Gonzales Survey Technicians: Scott Cowan and Joseph Sullivan January 2003
Table of Contents INTRODUCTION................................................................
1 SITE DESCRIPTION.............................................................
2 HISTORY & CLASSIFICATION....................................................
2 H istory of U se.............................................................
2 Classification..............................................................
2 CRITERIA FOR RELEASE TO UNRESTRICTED USE.................................
3 As Low As Reasonably Achievable (ALARA)....................................
3 Release Criteria for Soils.....................................................
3 Exposure Rate Guideline.....................................................
3 DECONTAMINATION PERFORMED 4
INSTRUMENTATION and BACKGROUND MEASUREMENTS.........................
4 Background Soil Concentrations of Concern.....................................
4 Exposure Rate Background...................................................
5 FINAL SURVEYS PERFORMED...................................................
5 Objectives and Responsibilities...............................................
5 Survey Plans..............................................................
5 Soil Sam pling.............................................................
6 Survey Summ ary...........................................................
6 Comparisons of Site Decommissioning Plan Requirements with Final Surveys Performed on the TPNH Land Area, Section C, Suspect Affected Area..........
6 RESULTS OF THE FINAL SURVEYS...............................................
7 Soil Sample Summ ary.......................................................
7 Exposure Rate Scans........................................................
8 Fixed Exposure Rate Measurements............................................
8 Exposure Rate Measurements at Soil Sample Locations............................
9 CONFIRMATORY SURVEY.......................................................
9 CONCLUSION..................................................................
9 List of Tables Table 1:
USNRC's Acceptable Surface Contamination Levels.........................
T-1 Table 2:
State of California's Acceptable Surface Contamination Levels.................
T-2 Table 3:
List of Instruments, Section C...........................................
T-3 Table 4:
General Atomics Gamma Spectroscopy Results of Background Surface Soil Sam ples.........................................................
T-4 Table 5:
Torrey Pines North Hillside (TPNH) Land Area (Section C, Suspect Affected Area), Soil Sample Results.............................................
T-7 ii
List of Figures (unpaged)
Figure 1:
Torrey Pines (Main) Site Land Areas Figure 2:
Torrey Pines (Main) Site Land Areas, Torrey Pines North Hillside, Section C Figure 3:
Torrey Pines North Hillside, Section C, Suspect Affected Fixed Exposure Rate and Scan Measurement Locations and Results Figure 4:
Torrey Pines North Hillside, Section C, Suspect Affected Area Soil Sample Locations and Exposure Rates at Locations Appendices Appendix A:- Final Survey Plan, Torrey Pines North Hillside, Section C, Suspect Affected Area iii
+. CENERAL A7OMICS Final Radiological Survey Report for the Torrey Pines North Hillside (TPN) Land Area (Section C, Suspect Affected Area)
Introduction General Atomics (GA) is continuing its efforts directed at decontaminating, as appropriate, and obtaining the release to unrestricted use of selected facilities and land areas at General Atomics.
GA has recently completed the Final Radiological Survey of the remaining portion of the Torrey Pines North Hillside (TPNH) Land Area; the suspect affected area of Section C, located on GA's Main Site. The TPNH Land Area is the strip of land that lies between the GA site boundary and the GA Controlled Area fence on the north and northwest side of GA's Main Site. This land area consists of hillsides with extremely steep slopes and dense ground cover. There are no paved surfaces, buildings or sewer systems within this land area.
This report addresses the Suspect Affected Area of Section C, which was excluded from the prior report covering the TPNH Land Area submitted to the Nuclear Regulatory Commission (NRC) and the State of California on August 29, 2002.1 Those portions of the TPNH Land Area have been released by the NRC.2 The Suspect Affected Area of Section C lies between the former Hot Cell Facility boundary and GA's site boundary, and measures approximately 9,100 ft2 (- 846 M2).
This land area is a steep hillside located between the GA's main site mesa and a dedicated open space area in which any development is prohibited by land zoning restrictions. It is extremely unlikely that GA, or anyone in the future, would develop or build on this land area.
This report documents the results of GA's radiological measurements and soil sampling and analysis completed on this portion of the Torrey Pines North Hillside Land Area. The results of these surveys and analyses demonstrate that this land area meets the U.S. Nuclear Regulatory Commission (NRC) and State of California DHS Radiologic Health Branch (State) approved criteria for release to unrestricted use as specified in GA's NRC-and State-approved Site Decommissioning Plan.
Asmussen Letter dated August 30, 2002 (696/CAL-3508), "Request to Release Certain Portions of General Atomics' Facility to Unrestricted Use and Delete them from its License:
Namely, Torrey Pines North Hillside (TPNH)Land Area - Sections A, B, D and Unaffected Areas of Section C.
2 NRC SNM-696 License Amendment No. 75 releases the TRIGA Trailer Land Area and Portions of Torrey Pines North Hillside (Sections A, B, D and Unaffected Area of Section C) to Unrestricted Use I
SCGENERA AToMicS Final Radiological Survey Report for the Torrey Pines North Hillside (TPN) Land Area (Section C, Stispect Affected Area)
Site Description The TPNH Land Area is a steep hillside located on GA's Main Site (see Figure 1). The land area is adjacent to, and bounded on the north, by a dedicated open space area in which any development is prohibited by land zoning restrictions.
This land area consists of hillsides with extremely steep slopes and dense ground cover; most of this ground cover was removed for survey purposes. There are no paved surfaces, buildings or sewer systems within this land area. The Suspect Affected Area of Section C, the subject of this release request, borders the northern most portion of the west boundary of the former Hot Cell site and measures approximately 9,100 ft2 (- 846 m2) as shown in Figure 2.
History and Classification History of Use There is no known history of use or storage of radioactive material within this land area.
During the performance of the Final Survey in accordance with the Final Survey Plan prepared for the TPHN Land Area, elevated soil activity concentrations and direct exposure rate measurements were detected in this portion of TPHN Section C. This portion of the TPNH Land Area was then reclassified and excluded from the Final Report being prepared for the TPNH Land Area to allow time for more detailed surveys and possible decontamination efforts.
The more detailed survey identified radioactive contamination above background levels; however, concentrations were still below the NRC-and State-approved soil release criteria specified in GA's Site Decommissioning Plan. Still, GA decided to remove soil in areas having elevated concentrations (see "Decontamination" section below). After decontamination was performed, the Final Radiological Survey commenced.
Classification Section C of the TPNH land area lies adjacent to the former Hot Cell Site. Elevated dose rate levels and soil activity concentrations were detected in a portion of this section during the first Final Survey. Consequently, this portion of Section C was reclassified as a Suspect Affected Area. The rest of Section C remained an Unaffected Area and was included in the first report submitted for the TPNH Land Area.
2
+4 CENERALArOMICs Final Radiological Survey Report for the Torrey Pines North Hillside (TPN) Land Area (Section C, Suspect Affected Area)
Criteria for Release to Unrestricted Use As Low As Reasonably Achievable (ALARA)
During decommissioning efforts, GA attempts to decontaminate to levels as close to "background" as possible and as far below the approved Soil Release Criteria as reasonably achievable.
Release Criteria for Soils The approved release criteria, for the predominant radionuclides found in the soil at GA, (above natural background concentrations), as identified in GA's U. S. NRC-and State-approved Site Decommissioning Plan, is 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 If more than one radionuclide exists, the sum of the fractions of the concentrations is calculated as follows:
n C,
F
-=
<1 Where:
C, = The average concentration levels of radionuclide i in the sample (above background).
L, =
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 [tR/hr above natural background levels.
3
+
GE1ERALATOMICS Final Radiological Survey Report for the Torrey Pines North Hillside (TPN) Land Area (Section C, Su~pect Affected Area)
Decontamination Performed During decommissioning efforts, GA always attempts to decontaminate to levels as far below the approved soil criteria as reasonable and as close to "background" as possible. In the Suspect Affected Area of Section C, two (2) locations where elevated levels were identified were remediated.
Elevated dose rate measurements (measured using a microR meter) were detected in one location at the base of an erosion gully northwest of the former Hot Cell site boundary. Approximately 300 ft3 (- 8.3 m3) of soil was removed and disposed of as low level radioactive waste from this location (contaminant was primarily Cs-137). Dose rate measurements taken in this area following decontamination were not discernible from natural background levels.
In the second location, soil with elevated concentrations of Cs-137, ranging from -40% to -60%
of the approved release criteria, was identified in the Suspect Affected Area of Section C adjacent to the northwest boundary of the former Hot Cell site. Approximately 900 ft3 (- 25 m3) of soil was removed from this area and packaged for disposal as low level radioactive waste.
Soil samples taken after decontamination efforts were complete showed levels -20% or less of the approved release criteria. Considering the location of the contaminated soil (a steep, uninhabitable, unoccupied, normally inaccessible hillside), GA believes that levels achieved after decontamination were As Low As Reasonably Achievable (ALARA).
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, and (5) typical background readings. Portable instrument calibrations are conducted using only NIST traceable radioactive sources and calibrated semiannually.
Background Soil Concentrations of Concern Typical background concentrations measured by gamma spectroscopy in soil near the GA site have been established (at the 95% confidence level) and are provided in Table 4 along with the locations where these samples were taken.
4
+ CEMERALATOmIC$
Final Radiological Survey Report for the Torrey Pines North Hillside (TPN) Land Area (Section C, Suspect Affected Area)
Exposure Rate Background Typical exposure rate background for GA's site using a Ludlum Model 19 micro R meter is 12-18 RR/hr measured at 1 m from the surface of soil. This range of exposure rates can be measured south of Building 15 (an office building on the eastern portion of the GA site).
Measurements taken offsite in 10 different locations (9 offsite and 1 onsite at a non-impacted area near Building 15) over a period of 15 months averaged - 15 [R/hr (measured at I m from the surface).
Final Surveys Performed Objectives and Responsibilities The objectives of the final survey plans were: (1) to demonstrate that the measured concentration(s) of contaminant(s) in the soil (surface) are well below GA's approved release criteria for unrestricted use, and, (2) that the exposure rate measurements taken in these areas, measured at 1 meter above the surface, are less than 10 tiR/hr above background.
Survey Plans A Final Survey Plan was developed based on the previous history of use, or lack thereof, of the Torrey Pines North Hillside 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. The original Survey Plan was revised after some areas were re-classified and the hillside cleared for survey. See Appendix A for the Revised Final Survey Plan for the Torrey Pines North Hillside Land Area, Section C, Suspect Affected Area.
Surveys were taken in accordance with approved survey plans 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 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.
5
+,.
CENER*L ATOMicS Final Radiological Survey Report for the Torrey Pines North Hillside (TPN) Land Area (Section C, Su~pect Affected Area)
Soil Sampling The plan required soil samples to be collected in locations as indicated (approximately) on Figure
- 4. 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. The approximate sampling locations were documented on a drawing.
Soil samples were analyzed in GA's Health Physics Laboratory with a Canberra Low Sensitivity Gamma Spectroscopy MCA System using a high purity germanium detector. The system is calibrated using NIST traceable standards and performance checked daily. Soil samples were counted for a minimum of 30 minutes each. A 30 minute count was sufficient to detect the radionuclides of concern at levels below GA's approved soil release criteria.
Survey Summary Comparisons of the Site Decommissioning Plan requirements with the Final Surveys performed in relation to the percentage of surface area scanned, number of measurements (i.e., number of fixed radiation measurements), exposure rate measurements (jtR/hr) and soil samples taken are provided as follows:
SC*oTparison's of Site Decommissioning Plan Requiremients.with iý":,s, Final SurveysPerform~ed on the TPNH Land-Ara, Sect ti oCn Su"spe t "Affected A rea" D-Plan = GA Site Decommissioning Plan The total surface area to be released is approximately 9,100 ftO (-846 m2).
6 Survey Area**
Gridding
- of Exposure Rate Measurements
- of Soil Samples.
Require and~hr
'Aaye D-Plan* Requirements, Yes I per 4 m2 or 1 every 2m 36 total surface samples Suspect Affected Area A total of 212 measurements (4 samples per 10 m x 10 m)
(based on 846 m2)
Final Surveys Performed, Yes 1 every 2 m (212 measurements) 45 total surface samples Suspect Affected Areas
& 1 at each soil sample location (45)
+
& 100% surface scan of accessible areas.
1
+. GENERAL.TOmICs Final Radiological Survey Report for the Torrey Pines North Hillside (TPN) Land Area (Section C, Suspect Affected Area)
Results of the Final Surveys The results for the TPNH Land Area, Section C, Suspect Affected Area are provided in figures and tables as noted below:
Soil Sample Summary The highest concentration, lowest concentration and average for each radionuclide detected in the 45 soil samples collected and analyzed by gamma spectroscopy is provided in the following table. See Figure 4 for approximate soil sample locations and Table 5 for gamma spectroscopy results.
Average 1.41 0.15 0.49 0.13 1.35 1.60 Notes:
- 1. Average Minimum Detectable Activity (MDA):
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)
- 2.
The high concentrations for each isotope did not occur in the same sample. No sample had a sum of fractions greater than 1.0.
- 3.
The average activity is based on the numerical average of all (45) samples, using the MDA value when the isotope was not detected.
- 4.
Background is not subtracted. The average background is noted in Table 4.
- 5.
Soil sample locations are illustrated in Figure 5. Soil sample results are presented in Table 5.
The highest U-238 result (2.25 +/- 2.07 pCi/g) is within the natural background concentration range of 0.50 to 2.67 pCi/g for all positive natural background samples collected (see Table 4).
All results are far less than the approved release concentration.
7
+
CENER.LATOMics Final Radiological Survey Report for the Torrey Pines North Hillside (TPN) Land Area (Section C, Suspect Affected Area)
The highest U-235 results were 0.30 +/- 0.13 pCi/g at the surface (0-6"), collected at location HS C-21, as shown on Figure 5. This concentration is within the natural background concentration range of 0.04 to 0.35 pCi/g for all positive natural background samples collected (see Table 4).
All results are far less than the approved release concentration.
The fission product Cs-137 was identified, in low concentrations, in many of the soil samples.
The maximum concentration detected in the soil was 2.58 +/- 0.30 pCi/g (above background levels but only -17.2% of the release criteria) collected at location HS-C-10 as shown on Figure 5. The average concentration for all 45 samples is 0.49 pCi/g; near background levels. All samples were well below the approved release limit of 15 pCi/g.
The activation product, Co-60, was identified in trace concentrations in 11 out of 45 soil samples. The highest concentration measured was 0.29 +/- 0.12 pCi/g, collected at location HS-C 38 as shown on Figure 5. This concentration is far below the approved release limit of 8.0 pCi/g.
Thorium contamination was not present (as determined by process knowledge and gamma spectroscopy analyses of soil samples). All thorium results were at natural background concentrations (see Table 4).
Exposure Rate Scans 100% of the soil surface (-1" from the surface) within the Suspect Affected Area of Section C, was scanned using a 2"x2" NaI(T1) [tR gamma detector. The exposure rate ranged from 16 to 23
[.R/hr on hillside surfaces and 22 to 24 [iR/hr inside the storm runoff depression areas; see Figure 4 for approximate locations and results.
Fixed Exposure Rate Measurements Direct radiation levels were measured at 1 m from the surface, every 2 m, in the Suspect Affected Area, using a 2"x2" NaI(Tl) [tR gamma detector. Due to the large number of [tR/hr readings (a total of 212 measurements taken), only the highest readings (typically five readings per grid) are "provided in Figure 4.
The maximum reading measured at 1 m from the surface was 21 i[R/hr, which is less than 10
[LR/hr above a typical background level of 15 [tR/hr. Thus, all readings were less than the approved release criteria. See Figure 4 for exposure rate measurement locations and results.
8
+
CEmERAL ATOmicS Final Radiological Survey Report for the Torrey Pines North Hillside (TPN) Land Area (Section C, Suspect Affected Area)
Exposure Rate Measurements at Soil Sample Locations Fixed exposure rate measurements were taken at contact (within 1" of the surface) and at 1 meter from the surface at 45 soil sample locations using a 2" x 2" NaI(T1) ýtR gamma detector. The highest measurement at contact was 20 [tR/hr and the highest measurement at 1 meter from the surface was 19 jIR/hr. These results are at or near natural background levels. See Figure 5 for locations and results.
Confirmatory Survey GA decided not to perform an internal confirmatory survey in this area for the following reasons:
- 1. Extensive surveys were performed in accordance with the original and revised final survey
- plans,
- 2.
Extensive surveys were performed following decontamination efforts, and,
- 3.
Final survey results were far below the approved release criteria.
Conclusion Final contamination and radiation surveys, as well as the results of analyses of soil samples, as documented in this report, demonstrate that the Torrey Pines North Hillside Land Area, Section C, Suspect Affected Area meets the U.S. NRC-and State-approved criteria for release to unrestricted use.
9
TrAble 1: USNRC'S ACCEPTABLE SURFACE CONTAMINATION LEVELS
- j.
.NAveraecIadeS Mximumemo
-(dpim/100cxii)
J(apnijOO cm2)
(ajpm/l6O~Ci 2)1 U-nat, 235U, 238U, & associated decay products 5,000 a 15,000 a 1,000 a Transuranics, 226Ra, 228Ra, 230Th, 228Th, 23lPa, 227Ac, 100 300 20 1251, 121_
Th-nat, 232Th, 9°Sr, 223Ra, 224Ra, 232 U, 1261, 1331, 1311 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 9Sr and other noted above.
I a
Where surface contamination by both alpha-and beta/gamma-emitting nuclides exists, the limits established for alpha-and beta/gamma-emitting nuclides should apply independently.
b As used in this table dpm (disintegrations per minute) means the rate of emission by radioactive material as determined by correcting the counts per minute observed by an appropriate detector for background, efficiency, an geometric factors associated with the instrumentation.
c Measurements of average contaminant should not be averaged over more than 1 square meter. For objects of less surface area, the average should be derived for each such object.
d The maximum contamination level applies to an area of not more than 100 cm 2.
e The amount of removable radioactive material per 100 cm 2 of surface area should be determined by wiping that area with dry filter or soft absorbent paper, applying moderate pressure, and assessing the amount of radioactive material on the wipe with an appropriate instrument of known efficiency.
When removable contamination on objects of less surface area is determined, then pertinent levels should be reduced proportionally and the entire surface should be wiped.
f The average and maximum radiation levels associated with surface contamination resulting from beta-gamma emitters should not exceed 0.2 mRad/hr at 1 cm 2 and 1.0 mRad/hr at 1 cm2, respectively, measured through not more than 7 milligrams per square centimeter of total absorber.
T-1
",,bla 1.
TATP. A*lF 'A ACC*PTARE SURFACE CONTAMINATION LEVELS, J,
" ) Average:
' M-.Aximumoa Removableb, Nuc... es' (dpmi/100cm 2)
, '(dprn/100cm0
) J (dpm/100cm2)
U-nat, 235U, 238U, & associated decay 5,000 15,000 1,000 products Transuranics, 22 6Ra, 228Ra, 230Th' 228Th, 100 300 20 2 Pa, 27Ac, 1251, 1291 Th-nat, 232Th, 9OSr, 223Ra, 224Ra, 232U, 1261, 1,000 3,000 200 1331, 1I3_
Beta/gamma 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 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.
T-2
Table 4:. General Atomcis GainmmaSectoosi*,oyRestIlt of Background'Surface Sodl Samples'
+'Sept
-ber24, 2002 "137c 6co+
2 2 8 a
(22 2 Th)
(Total) Th 2 3 8uj,22 235u.
.Energy Peaks 661.6 key'.
1173 keV, 238 keVY 911 keV, 228Th + 232
- TTh, 63.3 (92.7) 144 (186)
Pbad).cld (2 28 AC)
~~jkeV~,2 keY Saple ID Rdo ucieCon cernrations (pC/g Results 12 c au
- 0inute 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+/-:t0.5 8 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 (0.26 +/- 0.14)
X-9 ND ND 0.61 +/-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 +/- 0.36 2.98 +/- 0.61 0.75 +/- 1.22 (0.13 +/- 0.07)
Samples collected and analyzed September, 2002 X-1 1 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 1.29+/-0.99 (0.14 +/-0.05)
X-14 ND ND 1.42 +/-0.19 1.59 +/-0.29 3.01 +/-0.48 0.67+/-0.71 (0.11 +/-0.05)
T-4
Table 4: General Atormcs Gamma Spectroscopy+ Results of Background Surface Soil Samples.,,
~j
~
September 24, 2002 I
T-5
- 137cs, 60C28h281a(3 Th)'
(Total) Th 23U 235U 22 13'h (63.3 (92.7)1 4
,Ener-gy Peaks-661.6 keY 1173 keV, 238 keY 911 keY V
~
h+
2 h 6.(27 144 (186)
../
",<(212 Pb)(
2 28 Ac)
Ž,
.'..keY 2344
- Sample ID'*:+#*
.,+ *,+
,;+ + - *+;*S:+
+++:+
Raiodnuclide Concentrations (pX i/g) - esults+/- 2 u.- 30 Min'ute Cout +v *.,.+ +:.*... : ++.+,
. i,
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)
Notes:
- 1.
ND means not detected.
- 2.
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)
Sample Locations:
X1 Sorrento Valley Road near sample location ST65 on the hillside -1 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, - 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).
X1l 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).
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:. Torrey Pln~es North'Hillside (TPNH) Land Area (Section CSuspect ffectedArea) Sil SampleResuts, Bakron No
'7'ctd 30po~o.n minut count.
U-I23,8,'
(Th-234. 63keV, 93*
- .keViused when 63
,;ke'Vis not pre'sent) i U-235, (1 44 keV, 186, keVY Iused when,144 keV is' K ' s not present) :'iK (662 keV),ý,,
5"{.
,'.
SCo.6(V'>
~(1170 keV)',&
-, Th-228 (Pb-214: 238 keY)
Th-232" (Ac-228:91 1 keV).
1 HS-C-1 ND 0.12 +/- 0.06 ND ND 1.34 +/- 0.25 1.41 +/- 0.26 2
HS-C-2 1.30_+/-.1.23 0.13_+/-.0.06 0.10_+/-.0.05 ND 1.33+/-0.32 1.66+/-0.31 3
HS-C-3 ND 0.18_+/-0.10 0.33+/-0.07 0.13+/-0.06 1.57_+/-.0.35 1.52_+/-0.32 4
HS-C-4 1.76 +/-1.67 0.13_+/-_0.06 0.58_+/-_0.10 ND 1.05_+/-.0.16 1.02+/-0.26 5
HS-C-5 1.76 +/- 1.67 0.13 +/- 0.06 0.58 +/- 0.10 ND 1.05 +/- 0.16 1.02 +/- 0.26 6
HS-C-6 ND 0.12 +/- 0.03 0.28 +/- 0.07 ND 1.24 +/- 0.18 1.32 +/- 0.27 7
HS-C-7 ND 0.18 +/- 0.09 0.50 +/- 0.11 ND 2.06 +/- 1.42 2.06 +/- 0.49 8
HS-C-8 1.44 +/- 1.21 0.17 +/- 0.04 0.39 +/- 0.05 ND 1.43 +/- 0.22 1.67 +/- 0.22 9
HS-C-9 ND 0.18 +/- 0.12 0.05 +/- 0.04 0.14 +/- 0.09 1.50 +/- 0.35 1.53 +/- 0.34 10 HS-C-10 ND ND 2.58 +/- 0.30 0.19 +/- 0.12 1.34 +/- 0.27 1.80 +/- 0.45 11 HS-C-11 1.77 +/- 1.68 0.20_+/-.0.10 0.67 +/-_0.12 ND 1.81 +/-0.44 1.78 +/-0.35 12 HS-C-12 ND 0.13 +/- 0.04 ND ND 1.25 +/-0.18 1.63 +/-0.31 13 HS-C-13 ND 0.18 +/-0.08 0.34 +/- 0.07 ND 1.48 +/-0.31 1.38 +/- 0.29 14 HS-C-14 ND 0.08 +/- 0.11 0.06 +/- 0.05 ND 0.94 +/- 0.16 1.39 +/- 0.33 15 HS-C-15 0.96+/-_.1.07 0.08+/-0.08 1.48+/-0.17 0.15+/-0.63 0.91+/-0.16 1.14_+/-_0.25 16 HS-C-16 ND 0.06_+/-.0.08 0.90-+/-0.12 0.13+/-0.06 0.87_+/-0.13 0.82_+/-0.26 T-7 Sample ID
Table 5:,- Torrey Pines North Hillside (TPNH),Land Area (Section C,. Siuspect AffectedArea)Soil SampleReSUlts Radilonuclide Concentration'(pCi/g O
<~' < 1a-grouiid N~ot Subtracted, 30<minute count>,
ac' AA AA A
IA A.m.
U;,38,
"(Th-234: 63keV, 93 VkeV~usý6dwien 63' SkeVis~not present).
(.235' (144 keV,186 keY usedwhen'144 keV isý,
no..t:,
re e t, *,*
- Cs-137'..
>(662 keV)' 4 Co-60
(~<1170. keVY.
- ')< Th-228, (Pb-214: 238 k'eV)
Th-232 (Ac-228:,911 keV) 17 HS-C-17 1.49 +/- 1.52 0.18 +/- 0.07 0.42 +/- 0.11 ND 1.67 +/- 0.24 1.71 +/- 0.40 18 HS-C-18 ND 0.14 +/- 0.07 1.31 +/- 0.17 0.12 +/- 0.08 1.25 +/- 0.29 1.57 +/- 0.33 19 HS-C-19 2.25 +/- 2.07 0.26 +/- 0.10 0.24 +/- 0.08 ND 1.58 +/- 0.23 1.79 +/- 0.38 20 HS-C-20 0.64 +/- 0.84 0.22 +/- 0.07 1.31 +/- 0.17 0.16 +/- 0.07 1.48 +/- 0.22 1.60 +/- 0.35 21 HS-C-21 ND 0.30 +/- 0.13 0.23 +/- 0.09 ND 1.61 +/- 0.35 2.03 +/- 0.47 22 HS-C-22 ND 0.18+/-0.13 0.21 +/-0.11 ND 1.69 +/-0.37 2.39 +/-0.48 23 HS-C-23 ND ND 0.78 +/- 0.14 ND 1.39 +/- 0.27 1.94 +/- 0.44 24 HS-C-24 ND 0.09 +/- 0.09 0.21 +/- 0.08 ND 1.60 +/- 0.30 1.42 +/- 0.43 25 HS-C-25 1.38 +/- 1.32 0.10 +/- 0.06 0.28 +/- 0.07 ND 1.29 +/- 0.31 1.15 +/- 0.33 26 HS-C-26 ND ND 0.28 +/- 0.08 ND 0.88 +/- 0.17 1.68 +/- 0.40 27 HS-C-27 ND ND ND ND 0.67 +/- 0.18 1.09 +/- 0.26 28 HS-C-28 ND ND 0.65 +/- 0.12 0.05 +/- 0.08 1.11 +/- 0.17 1.32 +/- 0.37 29 HS-C-29 ND 0.08 +/- 0.05 0.35 +/- 0.08 ND 1.30 +/- 0.22 1.45 +/- 0.31 30 HS-C-30 ND 0.11 +/- 0.05 0.17 +/- 0.06 ND 1.14 +/- 0.19 1.28 +/-0.27 31 HS-C-31 ND 0.19 +/- 0.10 0.36 +/- 0.10 ND 1.68 +/- 0.37 2.00:+/- 0.47 32 HS-C-32 1.53 +/- 1.82 0.24 +/- 0.09 0.38 +/- 0.10 ND 1.67 +/- 0.37 2.03 +/- 0.47 T-8 Sample ID
Table5: Torrey Pines North Hillside (TPNHI)LandArea'(Section C, Suspect AffectedArea) Soil, Sampe R'esult
~~~* ~~~Radioniuclde Concentration (pCilg)
I K
>2<
U'2381 (Tht234: 63keV, 93 keV usd when 63 k&keVis not present) >,
(4 U-235 (144 keV,186 keV 1/2
- used when,144 keY, is"'
" ot presentj Cs.137<
<(662 keV) A Co-60 ;.
i~~(11 70 keV).=
Th-2282 (Pb-214: 238 keV)
KTh-232:
- (Ac.228: 911 keV) 33 HS-C-33 1.65 +/-_2.12 0.24_+/-0.16 1.48_+/-0.22 0.15 +/-0.10 1.58_t0.40 2.41 t+/-0.56 34 HS-C-34 ND 0.10 t 0.14 0.31 +/- 0.10 ND 1.65 +/- 0.41 2.30+/- 0.73 35 HS-C-35 ND ND 0.13 +/- 0.08 ND 1.27 +/- 0.19 2.12 +/- 0.46 36 HS-C-36 ND 0.23 +/- 0.13 0.44 +/- 0.12 ND 1.01 +/- 0.24 1.95 +/- 0.44 37 HS-C-37 ND 0.16 +/- 0.13 0.27 +/- 0.12 ND 1.73 +/- 0.41 2.56 +/- 0.53 38 HS-C-38 ND 0.24 +/- 0.12 0.82 +/- 0.14 0.29 +/- 0.12 1.79 +/- 0.31 1.50 +/- 0.44 39 HS-C-39 ND 0.06 +/- 0.06 0.11 +/- 0.05 ND 0.76 +/- 0.16 0.83 +/- 0.26 40 HS-C-40 ND 0.13 +/-0.07 0.18 +/-_0.06 ND 1.11 +/-0.19 1.16+/-0.30 41 HS-C-41 1.82 +/- 1.60 0.13 +/- 0.07 0.56 +/- 0.10 ND 1.63 +/- 0.34 1.74 +/- 0.40 42 HS-C-42 ND 0.16 +/- 0.07 0.44 +/- 0.10 ND 1.79 +/- 1.24 1.78 t 0.43 43 HS-C-43 1.40 +/- 1.51 0.10 +/- 0.05 0.78 +/- 0.11 0.03 +/- 0.03 1.22 +/- 0.28 1.31 +/- 0.27 44 HS-C-44 ND 0.08 +/- 0.06 0.18 +/- 0.06 ND 1.00 +/- 0.30 1.31 +/- 0.26 45 HS-C-45 ND ND 0.12_+/-0.07 ND 0.91 +/-0.15 1.41 +/-_0.35 Notes:
- 1.
ND means not detected.
- 2.
Average Minimum Detectable Activities (MDAs):
U-238 = 1.37 pCilg (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-9 Sample ID,,
I I
Figure 1: Torrey Pines (Main) Site Land Areas TORREY PINES NORTH HILLSIDE SUSPECT AFFECTED AREA of SECTION "C" Bunker Yard LINAC RTH LAND Bldg. 21/27 Utility Pad HOT CELL LAND TORREY PINES NORTHEAST "Yard TORREY PINES Reactors
& Land TORREY PINES EAST TFF CENTRAL TORREY-PINES SOUTH N
A UTILITY CORRIDOR
Figure 2: Torrey Pines Hillside Section "C" Unaffected Area Drainage Ledges Storm Drain Pipes Section C, Suspect Affected Area Overlap Area Section "B" Section "C" Suspect Affected Area
-9100 ft2
-846m 2 Torrey Pines Northeast Section "All LINAC North Land TRIGA B-21 mII IV S111I Hot Cell Land
Figure 3 : Torrey Pines Hillside, Section C Suspect affected, Fixed Exposure Rate and Scan Measuremer~t Locations and Results 4
4s4 0 'b
%' 44
o-Q.
19-21
-21 I
}
[
17-20 20-7 ad Reading N
Scan Range Ledges Fence Riprap Drainage Drainage Overlap Area Suspect affected Area Done in previous survey fnstnir Model Ludlum SIN 15134 Probe 2 "X 2" Probe SIN 16316 Notes:ICal Due Date 01/15
- 1. All fixed readings are in tR/I 1
- 2. Measurements were taken e shown on this mtap were the
- 3. Surface Scan Measurement 161 "1 16-18 n 3 Ludlum 3 48 153311 Nal 2"X2" Nal 69 155594 5/03 12/11/02 Surveys Conducted by: JI Sullivan & S. Cowan Dates: 10-29-02 to 11-04-02
/hr taken at -1 meter above the surface.,I 3very 2 meters. A total of 212 Measurements were taken. The 54 measurements
'highest measurements.
ts ranged 16 -23 gR/hr on the hillside and 22-24 laR/lir in the storm runoff depression.
Fixe XXX
- -X X
ob
ý'. Z/O 001- ý'),
19(y 4&ý
'11-00 z
Figure 4 : Torrey Pines Hillside, Section C Suspect affected, Soil Sample Locations and Exposure Rates at Locations 0%o 9C'o, 0),
HSC 21 0
HSC 22 HSC 30\\
HSC 19 e
HSC 20 0
HSC 18 HSC 23 9
13 HSC 14
ýHSC 45 27 44 HSC" HS4 43 Riprap Drainage Drainage Ledges Model Ludlum 3 Ludlum 3 S/N 151348 153311 Probe 2 "X 2" Nal 2" X 2" Nal Probe SIN 163169 155594 Cal Due Date 01/15/03 12/11/02 Notes:
Overlap Area
- 1. All readings are Surveys Conducted by: J. Sullivan & S. Cowan Dates: 10-29-02 to 12-26-02 in tR/hr taken at soil sample location, contact and -1 meter above the surface, shown in Table.
Suspect affected Area Done in previous survey I I 15-
ý 15 V
15l r>-ý
General Atomics' Final Radiological Survey Report For Torrey Pines North Hillside, Section C, Suspect Affected Area Appendix A Final Survey Plan
Page I of 3 October 4, 2002 Prepared By: W. T. LaBonte g
Approved By: -W
,V L.Q. Gonzales Final Radiological Survey Plan for Torrey Pines North Hillside Land Area Section C - Suspect Affected Areas This Final Survey Plan is for Torrey Pines North Hillside Section C - Suspect Affected Area which was excluded from the Torrey Pines North Hillside Open Land area release request submitted on August 29,2002. This strip of open land lies between the GA site boundary and the GA Controlled area fence north of the previous Hot Cell site. This land area consists of hillsides with extremely steep slopes and dense ground cover. This land area contains many apparent drainage pathways as evidenced by erosion gullies. There are no paved surfaces. This Final Survey Plan is for land surveys only. See Figure 1 for location.
The TPNH Section C - Suspect Affected Land Area is approximately 9,100 f 2 (-846 m2).
History and Classification History There is no known use or storage of radioactive material within this land area, however, elevated activity levels were found during the performance of the Torrey Pines North Hillside and Hot Cell Site Final Surveys. Soil was removed from the areas with elevated activity levels and disposed of as low level radioactive waste at a licensed burial facility.
Classification The Torrey Pines North Hillside Section C - Suspect Affected Area is classified as a Suspect Affected Area.
Survey Objectives and Responsibility The purpose of performing a final survey is to demonstrate that the radiological conditions within the Torrey Pines North Hillside Section C Land Area satisfy the NRC and State of CA guidelines for release to unrestricted use. The objectives include (1) to demonstrate that the residual activity concentrations in soil are below the approved release criteria and (2) to demonstrate that the exposure rates in occupiable locations are less than 10 p.tR/hr above background measured at 1 meter above the Tpn hillside Section C final survey plan.wpd
Page 2 of 3 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)
Exposure Rate Measurements The guideline value for exposure rates measured at I m above the surface, is less than 10 pR/hr above background.
Soil Samples 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 Eu-152 11 pCi/g If more than one radionuclide exists, the sum of the fractions of the concentrations is calculated as follows:
M~ L i C, =
The average concentration levels of radionuclide i in the sample (above background).
L, = The release criteria for radionuclide i.
The sum of the fractions must be less than or equal to one (1).
Alert Levels Soil Samples Activity levels >30% of soil release criteria values presented above for individual isotopes, or a sum of fractions >0.60.
Tpn hillside Section C final survey plan.wpd
Page 3 of 3 Exposure Rate Measurements
> 25 [tR/hr at surface
> 20 WtR/hr at 1 m Documentation Every survey conducted must be documented on a daily basis on a drawing showing the approximate locations surveyed. Include the results (including units), the technicians signature, date, instrument(s) used (including model and serial number of both the ratemeter and the detector), calibration due date,
% efficiency, background readings (if applicable) and any other applicable information.
Tpn hillside Section C final survey plan.wpd Final Radiolo'gicl SuriveyS Plan*ed for the Torrey ines North Hillside'Land Area,*;;.
Area'.
Grid
- Exposure Rate *Exposure Rate, Soil Sample R e'quir'e'd
@1 Im from
-Scan @1 inch,
""'"surface, jfom surface Suspect
- Yes, 1 measurement 100% of Take 4, equally Affected Area, 10m x 10 m every 2 m, plus 1 accessible spaced, surface (0-6")
Section C "4 at each soil sample surfaces samples in each 10 m 9100 ft2 location x 10 m grid.
(- 846 iln)
I I
I I
Figure 1: Torrey Pines Hillside
2 Section "C" Suspect Affected Area
-9100 ft2
-846m 2.,
<22222 i22 A
7 t22
'22224>,2 N
Section C, Suspect Affected Area
>2' Overlap Area 2222 2
/
2.2>
222 2
,2
22 Concr8te
>22 A (
/2,2
-
222 2>,
2 2,
LINAC North Land Hot Cell Land TFF B-22 Torrey Pines Northeast Drainage Ledges Drain Pipes fL....Z N
S11
ý1l
/