ML022610073
| ML022610073 | |
| Person / Time | |
|---|---|
| Site: | 07000734 |
| Issue date: | 08/30/2002 |
| From: | Gonzales L, Labonte W, Sullivan J General Atomics |
| To: | Office of Nuclear Material Safety and Safeguards |
| References | |
| -RFPFR | |
| Download: ML022610073 (52) | |
Text
GENERAL ATOMICS' FINAL RADIOLOGICAL SURVEY REPORT For The Torrey Pines North Hillside (TPNH) Land Area (Sections A, B, D, and Unaffected Area of Section C)
Prepared By: William LaBonte, Joseph Sullivan and Laura Gonzales Illustrated By: Stephen Finchum and Joseph Sullivan Final Survey Technicians: Joseph Sullivan, Cornelius Stanley, Will Shuck, and Barbara Lyons Confirmatory Survey Technicians: Barbara Lyons and Cornelius Stanley August 2002
+ GENERAL ATOMICS
Table of Contents INTRODUCTION.............................................................
1 SITE DESCRIPTION..........................................................
2 H istory of U se..........................................................
2 Classification...........................................................
3 CRITERIA FOR RELEASE TO UNRESTRICTED USE..............................
3 As Low As Reasonably Achievable (ALARA).................................
3 Release Criteria for Soils..................................................
4 Exposure Rate Guideline.....................................................
4 Decontamination Performed........................................................
4 Section A Decontamination Efforts..........................................
5 Section B Decontamination Efforts 5
Section C Unaffected Areas and Section D Decontamination Efforts...............
5 INSTRUMENTATION & BACKGROUND MEASUREMENTS........................
6 Background Soil Concentrations of Concern...................................
6 Exposure Rate Background................................................
6 FINAL SURVEYS PERFORMED................................................
6 Objectives and Responsibilities 6
Survey Plans............................................................
6 Gridding of the Area.....................................................
7 Soil Sam pling...........................................................
7 SURVEY SUMM ARY.........................................................
8 COMPARISONS OF SITE DECOMMISSIONING PLAN REQUIREMENTS WITH FINAL SURVEYS PERFORMED ON THE TORREY PINES NORTH HILLSIDE.........
8 RESULTS OF THE FINAL SURVEYS............................................
8 Soil Sample Results.....................................................
9 Independent Laboratory Analyses of Soil Samples 11 Exposure Rate Scans....................................................
12 Fixed Exposure Rate Measurements on Grid System...........................
12 Fixed Exposure Rate Measurements at Soil Sample Locations...................
12 CONFIRMATORY SURVEY...................................................
13 CONCLUSION..............................................................
13 ii
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:
Torrey Pines North Hillside Land Area List of Instruments.................
T-3 Table 4:
Background Soil Sample Results.......................................
T-4 Table 5:
Torrey Pines North Hillside Land Area Soil Sample Results and Exposure Rate Measurements at Soil Sample Locations.................................
T-5 List of Figures (not paged)
Figure IA:
General Atomics' View of Site Figure I B:
Torrey Pines (Main) Site Land Areas Figure 1C:
Torrey Pines North Hillside Land Area in Relationship to Surrounding Areas Figure 2:
Torrey Pines North Hillside Land Area Figure 3:
Torrey Pines Land Area Sections and Classifications Figure 4:
Torrey Pines North Hillside, Soil Sample Locations Figure 5:
Torrey Pines North Hillside, Section A & B, Soil Sample Locations Figure 5A:
Torrey Pines North Hillside, Section A & B, Soil Sample Locations for Samples Sent to STL Laboratories Figure 6:
Torrey Pines North Hillside, Section C & D, Exposure Soil Sample Locations Figure 7:
Torrey Pines North Hillside, Section A & B, Exposure Rate Scan Survey Locations and Results Figure 8:
Torrey Pines North Hillside, Section C & D, Exposure Rate Scan Survey Locations and Results Figure 9:
Torrey Pines North Hillside, Section A & B, Fixed Exposure Rate Measurement Locations and Results Figure 10:
Torrey Pines North Hillside, Section C & D, Fixed Exposure Rate Measurement Locations and Results Appendices Appendix A: Final Survey Plan for Torrey Pines North Hillside Land Area............
A-I Appendix B: GA's Internal Confirmatory Survey.................................
B-1 Appendix C: Comparisons of GA Severn Trent Laboratories, Inc. Results Including Severn Trent Laboratories, Inc. Analytical Report to GA C-I Appendix D: Photographs of Torrey Pines North Hillside Land Area.................
D-1 iii
+
CEN~RL Aomm Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
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 Torrey Pines North Hillside (TPNH) Land Area located on GA's Main Site. The Torrey Pines North Hillside 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 the GA Main Site ( Torrey Pines Mesa). 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. The land area included in this request measures approximately 66,060 ft2 (- 6,140 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. See Appendix D for photographs showing the hillside.
Due to the difficulty in safely performing radiological surveys on the steep slopes of the raw undeveloped land comprising TPNH, this area was excluded from earlier GA release requests.
Namely, LINAC North Land Area, Hot Cell Site, Torrey Pines Northeast, and the EA-1 Bunker Land Area. This land area borders on those parcels of land for which release requests have been made (The Hot Cell Site and Torrey Pines Northeast land areas have already been released).
To facilitate the logistics of conducting final radiological surveys on this area, and to clearly and logically classify the various portions of land comprising the TPNH land area, it was sub-divided into 4 sections identified as Sections A, B, C, and D. These sections were further sub-divided by Survey Classifications as follows:
Seto Sipc 'fetd raUAnXffcted Area
~~~Tt A
-1,630 ft2 (-150 in2)
-16,670 ft2 (-1,550 min)
-18,300 fte (-1,700 in)
B
-11,700 ft2 (-1,090 m2)
-8,600 ft2 (-800 m2)
-20,300 ft2 (-1,890 mi)
C To be the subject of a future
-19,400 ft2 (-1,800 i
- 2)
-19,400 ft2 (-1800 mn) release request.
D None
-8,060 ft2 (-750 M2)
-8,060 ft? (-750 n2)
Total 13,330 ft2 (-1,240 i 2) 52,730 ft2 (4,900 in2) 66,060 ft2 (-6,140 in2) 1
+ CEmAL AomCs Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
Figure IA shows GA's Main Site and Sorrento Valley Site, Figure 1B shows the Torrey Pines (Main) Site Land Areas and Figure IC shows the Torrey Pines North Hillside Land Area in relationship to surrounding land areas. Figure 2 shows the Torrey Pines North Hillside Land Area and Figure 3 provides a drawing showing the "classification" sub-divisions in each Section.
Finally, see Classification, below, for a description of the survey classifications.
GA is requesting both the U.S. Nuclear Regulatory Commission (NRC) and the State of California (DOHS/RHB) to release the Torrey Pines North Hillside Sections A, B, D, and the Unaffected Area of Section C to unrestricted use.
This report documents the results of GA's radiological measurements and soil sampling and analysis completed on the Torrey Pines North Hillside Land Area. The results of these surveys and analyses demonstrate that this land area meets the NRC and State of California approved criteria for release to unrestricted use specified in GA's Site Decommissioning Plan.
Site Description History of Use There is no known history of use or storage of radioactive material within this land area.
However, elevated radioactivity levels were found in the soil in Sections A, B and C during the performance of the LINAC North Land Area, EA-1 Bunker and Hot Cell Site Final Surveys. The elevated levels in Sections A were not above the release criteria for soil as noted below, however, GA decided to remediate this area to reduce the activity levels to as close to background levels as reasonably achievable. It is noted that the TPNH land area borders on parcels of land that ranged in classification, (for Final Survey purposes), from Unaffected Areas to Suspect Affected Areas. The TPNH land area contains many apparent drainage pathways from these land areas as evidenced by erosion gullies.
During the performance of the Final Survey in accordance with the original Final Survey Plan, it became apparent that very little of the land area was accessible for survey due to heavy vegetation growth. A gardening crew was used to defoliate the entire area. They performed this task so well, areas that were originally considered inaccessible became accessible. Following the performance of the Final Survey in accordance with the original Final Survey Plan, which was based on many areas being inaccessible, a revised Final Survey Plan, which considered all areas to be accessible, was issued. All survey results and area Classifications for survey purposes 2
+ tGERAL ATm, cs Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C) contained in this report are based on this revised Final Survey Plan which was developed to meet the requirements in GA's NRC-and State-approved Decommissioning Plan.
Classification Section A lies adjacent to the LINAC North Land Area (see Figure 3). Elevated U-235 concentrations were detected in a small area adjacent to the LINAC North Land area boundary during the performance of the original Final Survey. These activity levels were below the approved release criteria for enriched uranium in soil; however, the soil with the elevated activity was still removed and disposed of as low level radioactive waste. This portion of Section A was re-classified as a Suspect Affected Area. The remainder of Section A is classified as an Unaffected Area.
Section B lies adjacent to the EA-l Bunker and the TRIGA Reactor Complex Land Areas (see Figure 3). Elevated soil activity was detected in portions of this section during the first Final Survey. The soil with the elevated activity was removed and disposed of as low level radioactive waste. The areas where elevated activity was previously found were then re-classified as a Suspect Affected Areas. The remaining portions of this section are classified as Unaffected Areas.
Section C lies adjacent to the former Hot Cell Site. Elevated dose rate levels were detected in portions of this section during the first Final Survey. The portion of the area where elevated dose rates were found was re-classified as a Suspect Affected Area. The remaining portion of this section is classified as an Unaffected Area. Only the Unaffected Area is addressed in this report.
Section D, which lies adjacent to the Torrey Pines Northeast Land Area, is classified as an Unaffected Area. No contamination was found in Section D.
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.
3
+
CENERAL LrAmMN Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
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 the GA Site Decommissioning Plan, are provided as follows:
Enriched Uranium (U-234 + U-235) 30 pCi/g Thorium (Th-228 + Th-232) 10 pCi/g Depleted Uranium 35 pCi/g Cs-137 15 pCi/g Cs-134 10 pCi/g Co-60 8 pCi/g Eu-152 11 pCi/g If more than one radionuclide exists, the sum of the fractions of the concentrations is calculated as follows:
nCt -3 = <1 Where C, = The average concentration levels of radionuclide i in the sample (above background), and 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 [tR/hr above natural background levels.
Decontamination Performed A significant amount of decontamination work was performed in Sections A, and B. During decommissioning efforts, GA always attempts to decontaminate to levels as close to "background" as possible and as far below the approved Soil Criteria as reasonable.
In the TPNH Land Area addressed in this report, GA decontaminated the soil in those areas needing remediation to approximately 301% (or less) of the approved soil release criteria.
4
+
- CEMEAL ATIca Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
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). A summary of the decontamination effort for each section is provided below.
Section A Decontamination Efforts During the performance of the initial survey, an area with elevated soil activity was discovered northeast of Building 31-2 on a ledge just north of the fence that defined the former controlled area for LINAC North Land Area. The elevated area was approximately 66 ft long by 32.8 ft wide at the widest point. The predominate isotope was U-235 with a maximum concentration of 0.48 +/-
0.43 pCi/g. Approximately 200 ft3 of soil was removed from this area and disposed of as low level radioactive waste. Following decontamination activities, the residual activity was less than 30% of the approved release criteria.
Section B Decontamination Efforts During the performance of the initial survey, an area with elevated soil activity was discovered northwest of the EA-1 Bunker Land Area, adjacent to a natural drainage gully. The affected area was approximately 12-15 feet long by 6-8 feet wide. This area was approximately 75 feet from the EA-1 Bunker Land Area boundary. The primary contaminate was Cs-137 with a maximum concentration of approximately 25 pCi/g. Co-60, which was detected in trace quantities, was the only other activation or fission product detected. Uranium or Thorium contamination was not found. Due to the steepness of the slopes, access to the contaminated area could only be attained by the use of rented heavy earth moving equipment, with a long reach, positioned in the EA-1 Bunker Land Area. Fences and vegetation were removed to enable the equipment to reach the contaminated area. Approximately 1100 ft3 of soil was removed and placed in standard metal boxes for shipment to a licensed low level radioactive waste burial facility. To minimize the amount of radioactive waste generated by this decontamination effort, work crews excavated lower levels of contaminated soil, which was present in localized spots, using hand operated equipment and a "bucket brigade" for soil removal. An additional 100 ft3 was removed and placed in metal low level waste containers by this method. The residual activity, following decontamination efforts, was less than 30% of the approved soil release criteria. Photographs representing GA's decontamination efforts are provided in Appendix D.
Section C Unaffected Areas and Section D Decontamination Efforts Decontamination was not required in the Unaffected Areas of Section C or in any of Section D.
5
+C, uE mALATOMcs Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
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. All of the instruments used were calibrated semiannually and after repair, except for exposure rate meters which were calibrated quarterly.
Background Soil Concentrations of Concern Typical background concentrations measured by gamma spectroscopy in soil near the GA site have been established (at the 95% confidence level) and are provided in Table 4 along with the locations where these samples were taken.
Exposure Rate Background Typical exposure rate background for GA's site using a Ludlum Model 19 micro R meter is 12-18 [tR/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 [tR/hr (measured at 1 m from the surface). The range of 12-18 [tR/hr is typical at the GA site for the external dose rates measured at 1 meter from the surface. Background measurements @ 1 m above an asphalt surfaces are generally higher due to the higher concentrations of naturally occurring radioactive material. This background fluctuates depending upon the asphalt batch used and the date applied. This background, (measured at 1 m from the surface) ranges from 22-30 [LR/hr.
Final Surveys Performed Objectives and Responsibilities The objectives of the final survey plans were: (1) to demonstrate that the results of analyses of soil samples 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 [tR/hr above background.
Survey Plans A Final Survey Plan was developed based on: 1) the previous history of use of the Torrey Pines North Hillside Land Area, 2) the radionuclides of concern for this area, 3) the potential for 6
+ cENi'AL AmocS Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C) contamination, 4) the various types of surfaces encountered and, 5) the classification of the various areas. The original Survey Plan was revised after some areas were re-classified and the hillside cleared of vegetation for the survey. See Appendix A for the Revised Final Survey Plan for the Torrey Pines North Hillside Land 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.
Gridding the Area The hillside area was gridded in 10m x 10m grids using a 10 m rope and grid stakes. However, they do not appear as 10m x 10m grids on the figures due to the steepness and unevenness of the terrain and the difficulty in preparing drawings that are to scale. As a result, no dimensions are provided in the figures.
Soil Sampling The plan required soil samples to be collected in approximate locations as indicated 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, sufficient time to detect the radionuclides of concern at levels below GA's approved soil release criteria.
7
+ cEmHDALA mwmC Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
Survey Summary Comparisons of the Site Decommissioning Plan requirements with the Final Surveys performed in relation to the number of fixed exposure rate measurements ([tR/hr) and soil samples taken are provided as follows:
D-Plan = GA Site Decommissioning Plan The total surface area to be released is approximately 66,060 ft2 (-6,140 m2).
Portions of the land closest to the former Hot Cell Site and EA-1 Bunker Site (Sections A and B) had been surveyed during other surveys; i.e., there are some overlapping areas. These overlap areas are shown in the applicable Figures.
Results of the Final Surveys The results for the Torrey Pines North Hillside Land Area Final Surveys are provided in figures and tables as noted below:
8
- ,Compans4n4Sit eD ecoiiiissioning Pl'n Requiremnents with Fina Siurveys 'Peormed on,.,.
7 *,6nthe Torre nsNon'Hilside-Sections AB4) and UnaffectedArea of Section C To ie o6ide ande Bo__o am,__es
"ýSurvey Area;
,ridn
~
ofxpos ure ait edeauremniits' olSm s
Reuired,?i0f-.
AI Tta on A-
-A.
0 A
D-Plan*
No I per 10i 2, or I per 3m plus 1 at Not Required Requirements, each soil sample location for a total Unaffected Area 4 of 490 samples based on 4900 m2.
Final Surveys Yes 490 fixed measurements, plus 1 at 89 total surface (0-6") samples Performed, each soil sample location, and 25%
38 in Section A, Unaffected Area surface scan.
19 in Section B, 4
-21 in Section C, and 11 in Section D.
D-Plan*
Yes 1 per 4 mr 2 or I every 2m for a total 4 samples per 10 mx 10 m Requirements, of 310 measurements based on 1240 grid for a total of 48 Suspect Affected Area m0.
Final Surveys Yes 310 fixed measurements, plus 1 at 54 total surface (0-6")
Performed, each soil sample location, and 100%
10 in Section A, and Suspect Affected surface scan.
44 in Section B.
Areas -41
+ CENERALA*TM*MCS Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
Soil Sample Results Soil samples were collected in accordance with the Final Survey Plan and consistent with the requirements of GA's NRC-and State-approved Decommissioning Plan. The approximate locations where soil samples were collected are shown in Figure 5 (for samples collected in Sections A and B) and Figure 6 (for samples collected in Sections C and D). A total of 143 soil samples were collected during the final survey and analyzed by gamma spectroscopy. The detailed results are provided in Table 5.
The highest and lowest concentration of each radionuclide detected in the 143 soil samples is provided in the following table as well as the average concentration for each radionuclide.
Ii AKaionudilid'e'Conceniitrtio'n'('P di)
- 2.
-137C
-ThM 235h~
8 ;
High 2.03 +/- 0.22 0.36 +/- 0.13 2.22 +/- 0.30 2.48 +/- 0.55 3.99 +/- 1.95 0.39 +/- 0.48 Low 0.01 +/- 0.04 0.02 +/- 0.04 0.55 +/- 0.09 0.39 +/- 0.08 0.28 +/- 0.70 0.05 +/- 0.13 Average 0.22 0.14 1.47 1.69 1.59 0.16 n=143 Notes:
- 1.
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 = 0.15 pCi/g ( average of 1173 + 1332 keV peaks)
Th-228 = 0.21 pCi/g (238 keV peak)
Th-232 = 0.43 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 (143) 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 Figures 5 and 6. Soil sample results are presented in Table 5.
9
+
GEANELATuiMcs Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
Evaluation of Cs-137 Results The fission product 137Cs was measured, in low concentrations, in many of the final soil samples.
The maximum concentration detected in the soil was 2.03 +/- 0.22 pCi/g (- 14% of the 15 pCi/g limit) with an average concentration of 0.22 pCi/g. No other fission products were detected.
Evaluation of Co-60 Results The activation product Co-60, as identified in trace concentrations in only 3 out of 143 soil sample results. The highest concentration measured was 0.36 +/- 0.13 pCi/g, far below the release criteria for Co-60 of 8 pCi/g. No other activation products were detected.
Evaluation of Thorium Results Thorium contamination was not present (as determined by process knowledge and gamma spectroscopy analyses of soil samples). All thorium results were at, or near, normal background levels.
Evaluation of Uranium Results Uranium Isotopic Results - Two soil samples were sent to Severn Trent Services (STL)
Laboratories Inc. for uranium isotopic analysis to determine the U-234:U-235 ratio, to estimate the uranium enrichment and to compare with gamma spectroscopy results. The samples sent were collected during decontamination (before final soil samples were taken). The STL laboratory results are provided in Appendix C.
Sample STL Laboratory Uranium Isotopic Results U-234:U-235 Estimated IDI Radionuclide Concentration (pCi/g)
Ratio (
U-235 U-234 U-235 U-236 U-238 HS-A-14 8.8 -- 2.0 0.52 +/- 0.20 0.0 +/- 0.0 1.91 +/- 0.50
-17:1
-4%
HS-A-28 2.10_ +/-0.58 0.22 +/- 0.14 0.0 +/- 0.0 1.80 +/- 0.51
-9.5:1
-1.8%
(') U-234 concentration/U-235 concentration
() % U-235 = g U-235/g total uranium as shown in the following example for sample HS-A-14.
(8.8 pCi U-234/g of sample,)(lg U-234/6245.75e6 pCi U-234) =
1.4le-9 g U-234/g of sample (0.52 pCi U-235/g of sample)(lg U-235/2.16e6 pCi U-235) =
2.41e-7 g U-235/g of sample (1.91 pCi U-238/g of sample)(lg U-238/0.33e6 pCi U-238) =
5.79e-6 R U-238/g of sample Total =
6.03e-6 g U/g of sample Therefore: % U-235 = g U-235/g U = 2.41e-7/3.28e-6 = 0.04 (-4% enriched uranium) 10
+
cERnLm*O*mws Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area: of Section C)
U-235 contamination was present only in Section A as determined by process knowledge and sample analysis results. Using the highest U-234:U-235 ratio (17:1) and the highest U-235 final soil sample result (0.39 +/- 0.48 pCi/g at location HS-A-9; 0.39 +/- 0.10 at location LNLA-S-152; and 0.39 +/- 0.11 at location LNLA-S-164, all shown on Figure 5); the total enriched uranium measured in the sample having the highest U-235 concentration was -7.0 pCi/g, which is well below the 30 pCi/g (-23%) approved soil release criteria for enriched uranium (U-234 + U-235).
Depleted U-238 contamination was not present in any Section, as determined by process knowledge. The U-238 present is due to the enriched uranium identified and/or natural U-238 present in soil. The highest U-238 result (3.99 +/- 1.95 pCi/g) was far below the 35 pCi/g limit for depleted uranium. All results are far less than the approved release concentration.
Independent Laboratory (STL Laboratory) Analyses of Soil Samples Two (2) soil samples from Section A and five (5) soil samples from Section B were sent to an outside contracted laboratory (Severn Trent Laboratories) for independent analyses following gamma spectroscopy analysis performed by the GA Health Physics laboratory. The samples sent were those having the highest concentrations taken in areas prior to or during the remediation.
Uranium Isotopic analysis was performed on the soil samples from Section A because this section is adjacent to an area that utilized enriched uranium. Strontium-90 analysis was performed on the samples from Section B because Sr-90 was utilized at the EA-1 Bunker, which is adjacent to this section. Gamma spectroscopy analysis was performed to compare results with GA's gamma spectroscopy results. Plutonium isotopic analysis was performed to demonstrate that plutonium contamination was not present in the soil.
Appendix C provides a summary of STL Laboratories gamma spectroscopy, isotopic uranium, isotopic plutonium and Sr-90 results, a comparison of GA's results with STL's results, and the analytical report from STL Laboratories. A summary of the data provided in Appendix C is as follows:
- 1.
A comparison of STL Laboratories gamma spectroscopy analysis and GA's gamma spectroscopy analysis is provided in Appendix D. In general, the results were in agreement especially when detectable contamination was measured.
- 2.
Plutonium (238,239,240) was not detected in any of the samples analyzed.
- 3.
Strontium-90 was not detected in any of the samples analyzed.
11
+c.mNERAL ArojwIc Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
Exposure Rate Scans Exposure rate scans were performed in 25% of accessible unaffected areas and in -100% of suspect affected areas with a NaI(T1) gamma detector held approximately 1" from the surface.
The exposure rate ranges measured in Sections A and B are shown in Figure 7. Scan results ranged from 13-23 [tR/hr on the hillside and 19-28 RxR/hr in storm runoff depressions and gullies (naturally higher backgrounds are expected in pits, trenches, depressions and gullies).
The exposure rate ranges measured in Sections C and D are shown in Figure 8. The results ranged from 15-25 tR/hr.
Fixed Exposure Rate Measurements on Grid System Direct radiation levels were measured at 1 m from the surface, every 3 m in the unaffected areas and every 2 m in the suspect affected areas, using a 2"x2" NaI(T1) gamma detector.
Approximate fixed exposure rate measurement locations for Sections A and B are shown in Figure 9 as well as the range of results in each grid or partial grid. Measurements were 20-24
[tR/hr; the highest measurement outside of the drainage ditch was 21 [iR/hr which is less than 10 VR/hr above corresponding natural background (the release criteria).
Approximate fixed exposure rate measurement locations for Sections C and D are shown in Figure 10 as well as the range of results in each grid. Measurements were 13-21 [tR/hr on the hillside and 22-24 htR/hr in the drainage ditch which is less than 10 [tR/hr above background (the release criteria).
Fixed Exposure Rate Measurements at Soil Sample Locations In addition to the fixed exposure rate measurements taken on a grid system, fixed exposure rate measurements were also taken 1 m from the surface at each of the 143 final soil sample locations. The 143 tiR/hr measurements are provided in Table 5. The measurements ranged from 15-24 itR/hr as follows:
Section Range of Exposure Rate Measurements A
16-24 htR/hr B
15-20 [lRhr C
15-20 [tR/hr D
16-18 [tR/hr 12
+vcENERALtiam-o Final Radiological Survey Report For The Torrey Pines North Hillside Land Area (Sections A, B, D, and Unaffected Area of Section C)
Confirmatory Survey Following the completion of the Final Survey, a Confirmatory Survey was performed, by GA HP technicians. The GA Confirmatory Survey was conducted in accordance with an approved survey plan. This survey consisted of:
(1) Twenty (20) surface (0-6") soil samples.
(2) Twenty-eight (28) fixed exposure rate measurements at 1 meter from the surface, plus 1 fixed measurement at each soil sample location.
(3)
Exposure rate surface scans (with a 2"x 2" NaI(TI) with detector held within - 1" of the surface) performed on 10% of the Unaffected Areas and 100% of the Suspect Affected Areas.
All measurements were in agreement with the final survey results and all measurements were below the applicable release criteria. See Appendix B for the survey plan and detailed results.
Conclusion Final contamination and radiation surveys, as well as the results of analyses of soil samples, as documented in this report, demonstrate that Sections A, B, D and Unaffected Area of Section C of the Torrey Pines North Hillside (TPNH) Land Area meet the approved criteria for release to unrestricted use.
13
Table b IJSNRC'S ACCEPTARLE STIRFACF. CONTAMTNATTONLEVFT.
1 Nuclides Averagebe.?
Maximumbd~f Removableb.0 I
(dpm/100cm2)
(dpm/100 cm')
(dpm/100cm2)
U-nat, 2 3 5 U, 2 3 8U, & associated decay products 5,000 a 15,000 a 1,000 a Transuranics, 226Ra, 228Ra, 230°T, 22STh, 231Pa, 227Ac, 100 300 20 125i, 129I Th-nat, 232Th, 90Sr, 223Ra, 224Ra, 232U, 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 90Sr and other noted above.
a Where surface contamination by both alpha-and beta/gamma-emitting nuclides exists, the limits established for alpha-and beta/gamma-emitting nuclides should apply independently.
b As used in this table dpm (disintegrations per minute) means the rate of emission by radioactive material as determined by correcting the counts per minute observed by an appropriate detector for background, efficiency, an geometric factors associated with the instrumentation.
c Measurements of average contaminant should not be averaged over more than 1 square meter. For objects of less surface area, the average should be derived for each such object.
d The maximum contamination level applies to an area of not more than 100 cm e
The amount of removable radioactive material per 100 cm.2 of surface area should be determined by wiping that area with dry filter or soft absorbent paper, applying moderate pressure, and assessing the amount of radioactive material on the wipe with an appropriate instrument of known efficiency.
When removable contamination on objects of less surface area is determined, then pertinent levels should be reduced proportionally and the entire surface should be wiped.
f The average and maximum radiation levels associated with surface contamination resulting from beta-gamma emitters should not exceed 0.2 mRad/hr at 1 cm2 and 1.0 mRad/hr at 1 cm 2, respectively, measured through not more than 7 milligrams per square centimeter of total absorber.
T-1
Table 2: STATE OF CA ACCEPTABLE SURFACE CONTAMINATION LEVELS Nuclides' Averageb'f Maximumb'A Removableb"f (dpm/100cm2)
(dpm/100cmi)
(dpm/ll0cm2)
U-nat, 235U, 238U, & associated decay 5,000 15,000 1,000 products Transuranics, 226Ra, 28Ra, 230Th, 228Th, 100 300 20 231Pa, _27Ac, 1251, 1291 Th-nat, 232Th, 9OSr, 2 3Ra, 224Ra, 232U, 1261, 1,000 3,000 200 1331, 1311 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 '.
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 cm' 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
r 4k
~
~
- ~
j~V
?
Thble 3:tist 'f Tnstrumin~nts-Torrev Pii NortI'"IiIid6Sections A, B,;D and UnafftededArea of SectioniCkt
,ýýInstrumnent
.. t Detector
'Ranie iaii-to
EfSec'-
- y.
C'g~u Descrptiofi Ludlum Ludlum Model 44-10 Model 3 Nal M1) Scintillator Four Ranges 06-08-02 NA 10-18 IpR/hr 2 inch x 2 inch Nal MT) scintillator Used for measuring SIN 153311 Gammna Detector 0-500 IpR/hr external dose rates on the surface and at one meter.
SIN 155594 Ludlumn Ludlum Model 44-10 Model 3 Nal (M1 Scintillator Four Ranges 01-08-02 NA 10-1 8 paR/hr 2 inch x 2 inch Nal (TI) scintillator. Used for measuring SIN 153551 Ganmm Detector 0-500 ipR/hr 07-09-02 external dose rates on the surface and at one meter SIN 155109 Ludlum Ludlum Model 44-10 Model 3 Nat (TI) Seintallator Four Ranges 02-05-02 NA 10-18 p*R/hr 2 inch x 2 inch Nal (T1) scintillator. Used for measuring SIN 153590 Ganuma Detector 0-500 IVR/hr 06-08-02 external dose rates on the surface and at one meter S/N155190 Ludlum Ludlum Model 44-10 Model 3 Nal (TI) Scintillator Four Ranges 02-05-02 NA 10-18 piR/hr 2 inch x 2 inch Nal (TI) scintillator. Used for measuring SIN 151348 Gamma Detector 0-500 piR/hr external dose rates on the surface and at one meter S/N 154618 Canberra Canberra Model 2404 Low Level m/e4 gas proportional Low Level Gas Flow Proportional NF A As needed 30%
Varies with counting system used to count wipes for removable S/N Counter Detector Sample contamination.
Model 2404 Results are usually reported as dpm/Use cme.
Canberra Gamma Spectroscopy High Purity N1A As needed Varies with Vanes w0th Gamma Spectroscopy MCA system using a high purity System Germanium Detector Sample Sample Germanium detector.
S/
154618 I
T-3
Table 4: Gamma Spectroscopy Results of Background Soil (Surface)
Samples Radionuclide Concentrations (pCi/gm) - Results +/- 2u-30 Minute Counts Sample ID 137
'0Co 228Ra Total 661.6 keV 1173 keV 238 keV
(' Th)
Thorium 63.3 (92.7) 144 (186) peak peak peak 911 keV 228Th +
keV peak keV peak peak 232Th X-1 ND ND 0.71 +/- 0.07 0.97.+/- 0.25 1.68 1.17.+/- 0.77 (0.13 +/-L 0.06)
X-2 ND ND 0.90-+/--0.13 1.49+/-0.31 2.39 1.91 +/- 1.18 (0.13+/--0.08)
X-3 0.06 +/- 0.04 ND 1.49 +/- 0.10 1.56 +/- 0.25 3.05 1.45 +/- 0.80 (0.23 +/- 0.09)
X-4 ND ND 1.52 +/- 0.23 3.22 +/- 0.61 4.74 3.74 +/- 2.18 (0.28 +/- 0.17)
X-5 ND ND 1.92 +/- 0.17 2.41 +/- 0.53 4.33 (4.49 +/- 1.64)
(0.32 +/- 0.16)
X-6 ND ND 1.02 +/- 0.08 0.96 +/- 0.23 1.98 1.31 +/- 0.80 (0.14 +/- 0.06)
X-7 0.13+/--0.08 ND 1.59+/--0.14 2.40+/--0.38 3.99 2.16 +/- 1.48 (0.18-+/--0.10)
X-8 ND ND 1.44 +/- 0.28 1.40 +/- 0.28 2.84 2.30 +/- 1.16 (0.14 +/- 0.09)
X-9 0.09+/--0.08 ND 0.89+/-0.10 1.27+/-0.31 2.16 1.59 +/- 1.05 (0.10+/--0.08)
X-10 ND ND 1.29+/-0.11 1.52+/--0.36 2.81 1.10+/--0.96 (0.16+/--0.08)
Notes:
- 1.
Surface (0-6") soil samples were collected on 06/05/00 and 06/06/00 by Ed Rudgers off GA's site but close to GA.
- 2.
Samples were counted 7/20/00 through 7/24/00 for 30 minutes (same count as the soil samples).
- 3.
ND means:
< 0.1 pCi/g for Cs-137
< 0.1 pCi/g for Co-60
- 4.
The numbers in parenthesis indicate that the peak in parenthesis was used rather than the preferred peak shown because the preferred peak was not identified.
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 - V2 mile from Building 37 (collected on the hillside)
X6 Roselle Street, East of sample location ST64 -1 / 2 mile from Building 37 (collected on hillside).
X7 Lusk Boulevard, from the hillside - I V miles from Building 37 (collected on the hillside).
X8 Vista Sorrento Parkway, - !/2 mile from Building 37 (collected on the hillside).
X9 Callahan Road, -
V2 mile from Building 37 (collected on the hillside).
XI0 Eastgate Mall road, -3 miles from Building 37 (collected in a field).
T-4
F-F-7 r-I r-i F777 Yr vu v' iw' n F:7 -IFT7 F-__i 1V77-I, Tabe
- ,Tore Pied~N~i~i~sde'Lfiid A S
a lpRie`iilts "ard-Exposure Ra~te Measur~ffie'nts aSo~ilSýiiipe Lcatin Radio U
n.,iuciL Concenitrationis(pCi/g),~.~.-
,'Back Nj;1itdc44 ri c~ou'ni C4$K
~~
T-5 4'
"'2'
'1/4'
.'
)osure Ratie',
pRlhr at I*
eftr from.,
sufk 4
p.-.
2 2
3 4
5 6
7 8
9 10 I I 12 13 14 15 16 17 I
T-6 I
I --
F-T r -- i, F --r
.TAk T6rr'e'Y'Pines Norihll h'"I'Isid'e-,'i e'
e, I&
Land'Ar A Soil Sarnol REsu an."txposure ýate'N[6su-ir&nents at Soil Satbple'L6cations".
Rills*de Section'A,,,,
adio'h uýcflde'Cofic-e'ifitýýfi I oiis I (kUg kground N& Subtracted, 30 mim count Exp'p'sure jkate,;
in ýR/hrat 1
,mete'efrom' slfdace,ý Co-60'.
[(1170 keV+1330, Th-228,,.
(Pli-214: 118 kcýý Th-232
I I --,-
I--
F--
I T-7 I 17 F F F- ~ ~I-[7 F -
7 F-.
[7-F
[-
r -
F-F-
[7-F----
[-
F-
[I -
[-7
[7-F1-~[7 F
77 F
Piiie'S'Nottli'Hamjle'ResiL1tsaIiA E~~ue Rate Me'asuremenfisat'eofinl
~~ ~ ~Radionuclid Cbncenitrations (oci/g)
~~
- ~
'Bi'k N~~ui~~d30 riin'.6 con~t-s" Eipostire Rate U-235
-01 C
Cs3Y60~
~~*
Th 228
"ý'Jh-2 e
~93 keV6'se'd wyhen' used when i 44,,
keVk /21~~'~
63keV P'eak is nib
.'kciV'p'ak~is~n6t' I}
een PC 4
<4 r',kn;t4
- .)'.
7t<+/-,t$'
1 T-8 F--
F---
I----
F----
I--
I---
F- -
I' F -
F F--
F r-F--
F-
[7-F-
W--
F -
FX' FV I - -
[---
I- -
- F -
Tabe 54TrryPieNothiilsd Ladrea Sbil Safiii le"Re'uilts and Exl~osir Rate Measuiremeiits 11S lSarniple Locations'"
"9 5-or..-
9ies o
b Hillside*
4..
-i at4 so*,4.
-~~WN S
4 iecti W,~
'1 7
,4,;4 4444 4444*
4.,,Radi outclide CoUiLLII4rUtitis (p 9
i
-s) 49 B4 a-ckgow1f
- 9'tSubtrcte
'30
i a94 count.
4
.444 U.23S -
- '444 *4Z4' <>4.9 <44.4' <
-Exp
.osuire Rate,
- meter froiii T-9 494 '4>
.,A. 44.44 474 '9' 44 4
44
.4 TPHS B-17 TPHS B-18 TPHS B-19 TPHS B-20 MIHS B-21 TPHS B-22 TPHS B3-23 TPHS B3-24 TPHS B-25 TPHS B-26 TPHIS B3-27 TPHS 13-28 TPHS B-.29 TPJIS B3-30 TPHS B3-31 MIHS B-32 11 i
I I
F'- Il ---.
F-F F- -
~ I FT, F--
[7 7
F-F I
F-- I r-,
F-11'Table 5: Toinirey Pines North Iillsideand Aaa Soil
-aip6k git idEpsueR eM tsetensa olSioeIoain
- ji~ii Sctoi
~
~
c<
-A---
~
~
~~f~iK Y
~
R'S" ti*
p
'BSi S~pe bciin
_____~~~~~-
ilsd on______
'Riki'oiu'cid6C~lC~nratins.',i/g
- ,ýBdckgr~un~d NoiSbrr'ed 0mn on
'1(1170 keV4433O0 (Ac-228: 911 keV)
I Exposure.Rate in pRihri ti mneter* from,
'srf
-e I
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 T-10 I
I F--_
I F-,
F- --,
F F
F
[7
[7 r
ry, r
r".
rw.
r;
r 7 F> ~7,F.
[77i7-
[7 Ta'býi~5'ý To~re'y Piiies Noirh Hillside Land 'Area S6iI 'S~anpioleRe'silt h"n'd',E~kpobs"a M-cMieihrýents at soil Saniple TLocations'
~~f
_______de__'
S B6c t<<o>,
~Radionucdide Concentrations (pCi) fackg rtitid Noit u i -~ced 30 mini. c(
Cs-137~
(662ke"V]
Expo~sure Rule miete from ~
surface" 16 17 17 15 16 18 17 19 17 18 18 18 15 19 T-11I
'
'4 >
/
C" 50 51 52 53 54 55 56 57 58 59 60 61 62 63
F F~F>-
F-'
F' 7
F>
F F
F
[
F r
I>
Fr -
Talie5 Tbrr'~iies N 'rtti HillsieLMA~
os i~t sidearnd e
il aipe6esultsadtExposure, Rate MAea s ure mieits atS Soil Saiiipl eLbcaiio ns
__________~ ~~~~
i A< e
~HlsdUiiffected, ra of SectioniC ir:
- ru II ExposureRate in pýIR/lir atI.
bmeter from Ssurface 19 16 16 15 16 16 16 16 20 19 17 18 18 19 15 15 16
ýi'6 id Chent io'mm./g
- .
2 3
4 5
6 7
8 9
10 11 12 13 14 15 16 17 T-12 F-
T-13 rr I
17I-I~ F7 W--
I7
[777
[.":
r:
[-!-T F
v U- ý! F- : r---
F-F-
I.-.
v w
r
r:
r
r r
r
w (77 r
F
Table 5::1 I
HS-D-I 2
HS-D-2 3
HS-D-3 4
HS-D-4 5
IIS -D-5 6
HS-D-6 7
HS-D-7 8
HS-D-8 9
tIS-D-9 10 HS-D-10 11 HS-D-11
[orrey:Pes 6Nort' HSslslde
'Land Area So1 ampple, Resilts andiExpjsureRate Measurements at Soil SampileLocations
<'Vt 4
r:'
r'
w> r:
rw. rw
-F N
,_,Rd'&ld'C ncnrtos(</)x I
Exposure Rate
.,;,'in i, R/hr t 1atI
- ::meter from,:
-surfacel Notes:
- 1. ND means not detected, which means the energy peak was not identified or the value was less than the average MDA for the geometry and counting time used.
- 2. Average Minimum Detectable Activities (MDAs):
U-238 = 1.58 pCi/g (63 keV peak)
U-235 = 0.15 pCi/g (186 keV peak)
Cs-137= 0.13 pCi/g (662 keV peak)
Co-60 = 0.14 pCi/g ( average of 1173 + 1332 keV peaks)
Th-228 = 0.21 pCilg (238 keV peak)
Th-232 = 0.43 pCi/g (911 keV peak)
- 3. Background is not subtracted from results. See Table 4 for Background soil concentrations.
T-14
Building Numbers Budding 1 Building 2 Building 7 Building 9 Building 10 Building 13 Building 14 Building 15 Building 19 Building 21 Building 22 Building 23 Building 25 Building 27 Building 27-7 Building 29 Building 29-2 Building 30 Building 31 Building 31-1 Building 31-2 Building 31-3 Building 33 Building 33-1 Building 33-5 Building 34 Building 34-1 Building 34-2 Building 34-3 Building 35 Building 35-1 Building 36 Building 37 Building 39 Building 39-1 Building 41 Building 42 Building 45 Building 63 Building 64 Building 65 Building 66 Building 66 I.-
Figure 1A: Main Site and Sorrento Valley Site Names Administration Science Laboratories A, B. C Cafeteria Experimental Building Maintenance Building Technical Office Building Technical Office East Technical Office East Swimming Pool Building TRIGA Building TRIGA Fuel Lab Building Hot Cell Waste Yard Building Experimental Area Experimental Area Experimental Area Emergency Vehicle Storage Building LINAC Complex TRIGA Storage Building Neutron Radiography Building ECF Cnbcal Building Storage Building Fusion Building Fusion Lab Building Fusion Building Annex 5 Fusion Doublet III Building Fusion Doublet III Capacitor Building Fusion Doublet III Lab Building Fusion Doublet Ill Storage Building Test Tower Building Facilities (Shipping & Receiving) Building Blower Assembly Building Sorrento Valley Building Sorrento Valley Building Storage Building Raw Stock Facility NDT Facility Helium Circulator Test Facility 3550 Dunhill St 11030 Roselle St
/
11040 Roselle St 3520 Dunhill St 3510 Dunhill St LOTS UCSD FENCING PROPERTY LINE 0
250 500 750 1000 I'll!
SCALE IN FEET N
A S
SITE OPEN SPACE
Figure 1B: Torrey Pines (Main) Site Land Areas TORREY PINES I IV S
LINAC Bunker Yard Bldg. 21/27 Utility Pad HILLSIDE HOT CELL LAND TORREY PINES NORTHEAST TORREY Reactors
& Land TORREY PINES EAST TFF L
L L
TORREY PINES SOUTH
Figure IC : Torrey Pines North Hillside Land Area in Relationship to Surrounding Areas N
FORMER HOT CELL LAND INAC LAND TORREY PINES EAST TORREY PINES CENTRAL
Figure 2: Torrey Pines North Hillside Land Area Section "C" Unaffected Area
-19400 ft2
-2650m 2
Riprap Drainage Natural Drainage Section "C" Suspect Affected Area
( In Future Report )
Ledges Drain Pipes Overlap Area
/ >;,;
Section "B"
-20,300 ft2
-1890m 2
Hot Cell Land I-.
.7 LII 2
7-
--/
LINAC North Land
//
TRIGA Building 21
/
I...
//
I, Al Torrey Pines Northeast
/
/
/
I-
/
I--.
Al s
Section "D"
-8060 ft1
-750m 2
Section "A"
-18,280 f12
-170Om 2 tN oooorý,ý"'
eo-*
.s a
/p
Section "C" Unaffected Area
-19.400 ftl2 Ii Figure 3: Torrey pines North Hillside, Sections and Classifications Riprap Drainage Section "C" Suspect Affected Area
( In Future Report )
Section "D" Unaffected Area
-8060 ft2 Section "B" Unaffected Area
-4300 ft2 Suspect Affected Area Unaffected Area To Be Covered in future report Overlap Area Section "B" Suspect Affected Area
-11,700 ft2 Section "B" Unaffected Area
-4300 ft2
-4300 ft2 Hot Cell Land Section "A" Unaffected Area
-18,280 ft2 Section "A" Suspect Affected Area
-1630 ft2 LINAC North Land
/r
/7
-I Torrey Pines Northeast
//
//
/
"TRIGA Building
,/,4
/
)21/
Drainage Ledges Drain Pipes EIZ1 N
S
/
Hot Cell Land
/
/
[i Figure 4: Torrey pines North Hillside, Soil Sample Locations Riprap Drainage Drainage Section "C" Unaffected Area
-19,400 ft2 Section "C" Suspect Affected Area
( In Future Report)
Section "D" Unaffected Area
- 8060 ft2 Section "B" Unaffected Area
-4300 ft2 Suspect Affected Area Unaffected Area To Be Covered in future report Overlap Area Section "B" Suspect Affected Area
-11,700 ft2 Section "B" Unaffected Area
-4300 ft2 Section "A" Unaffected Area
-18,280 ft2 Hot Cell Land Sectlon "A" "Suspect Affected Area
-1630 ft2 LINAC North Land
/
I
-I
"-7
,1 Torrey Pines Northeast
,. / /
Ledges Drain Pipes SIzz N
S OO/
/
I!
Figure 5 : Torrey Pines Hillside, Area A & B, Soil Sample Locations O 14 ci-Section "A" Suspect Affected Area
/
-1630 ft2 TPHS B 20 HSA 6 HSA 5 HSA 4 Riprap Drainage Drainage Ledges Drain Pipes Suspect Affected Area Unaffected Area TPHS i3 2
TPHS B 31 PHSB3is TPHS B39 TPHS B29-'
TPSB 7TPHS 0646 TH 6
TPTPHB 61 TPHSB 36 B
TPHSB3-----------3--
~TPHS B
17 S
B 2
TPHS B 3 4i +
i* PHS B 58 TPHSTPH B 35 ms+ + iTPHS B 42' OY
+
B 26' TP+HS B 59:
TPH S B 27 TP H S B,
+,
33' TP S 3
S B 19L++
rH B
9+
TPHSB825
+
TPHSB857*
+"
- ++"0 P HS:+8 32
]TPHS B56...
HS 4
TPHs B 40
+++!+.*.+
+,.
TPHS B17
,+*'+
S HSB 24 TPHS B 50 TPHS B 51
/
4, 1.9 o lw A4X A1 HSA 12 HSA 3 GENERAL ATOMICS Health PhYSlCS / LSNC Model Ser#
Pr#
Caldue Efft a(
M 3 151348 154618 02/05102 N/A M 3 153551 155109 07/08/02 N/A 7
M 3 153590 155190 02/05/02 N/A y
Comments:
Measurements in It R/hr were taken at each sample point @ contact and Imeter and appear in table 5.
Technician:
Date:
12/02/01 C STANLEY IB LYONSIJ SULLIVAN I R STOWELL
,,IZ++
C.,
U10 le'ýp I
\\
+
J
It Figure 5A : Section A and B Soil Sample Locations Sent To STL Laboratories Section "A" Unaffected Area Section "B" Unaffected Area q4 Section "B" Suspect Affected Area Section "B" Unaffected Area Surveys Conducted by: J. Sullivan Dates: 11-10-01 to 02-25-02 Notes:
Suspect Affected Area Unaffected Area HSA 1 Ledges Drain Pipes LIIIII Fig #
\\ I
Figure 6 : Torrey Pines Hillside, Area C & D, Soil Sample Locations N
S Section "c" Unaffected Area
-19,400 ft2 Riprap Drainage Drainage Ledges Drain Pipes IIIZI*°*
Section "c" Suspect Affected Area (In Future Report)
LIII Electrical boxes Suspect Affected Area Unaffected Area To Be Covered in future report Overlap Area Section "D" Unaffected Area
-8060 ft2
+
RATOMICS Health Phy$IC$ / LSNC Model Ser#
Pr#
Cal due Eff M 3 151348 154618 02/05102 N/A M 3 153551 155109 07/08/02 N/A y
M 3 153590 155190 02/05/02 N/A Comments:
Measurements in ji R/hr were taken at each sample point @ contact and 1meter and appear in table 5.
Technician:
Date:
12/02101 C. STANLEY I B LYONS I J SULLIVAN f R. STOWELL
Figure 7 : Torrey Pines Hillside, Sections A & B,Surface Scan Locations and Results Section "A" Unaffected Area Section "B" Unaffected Area Section "B" Suspect Affected Area IV S~
Section "B" Unaffected Area Section "A" Suspect Affected Area F,
F, I
,
I.
F 1
F I ii F
L Ii II I
Ledges Drain Pipes Suspect Affected Area Unaffected Area Surveys Conducted by: B Lyons, C Stanley, J. Sullivan, S Cowan & W. Schuck Date: 11-10-01 Notes:
- 1. All readings are in pR/hr taken at the surface. Results are shown in ranges.
- 2. 100% of safely accessible surface area scanned.
- 3. Scan results range from 13-23 pR/hr on the hillside and 19-28 pR/hr in storm runoff depressions.
Riprap Drainage Drainage LIII
Figure 8 : Torrey Pines Hillside, Sections C & D,Surface Scan Locations and Results Section "C" Unaffected Area Section "C" Unaffected Area S
Section "C" Suspect Affected Area
( In Future Report)
Section "B" Unaffected Area Riprap Drainage Drainage Ledges Drain Pipes Instruments Model Ludlum 3 Ludlum 3 Ludlum 3 S/N 153551 153590 151348 Probe 2 "X 2" Nal 2" X 2" Nal 2" X 2" Nal Probe S/N 155109 155190 154618 Cal Due Date 01-08-02 02-05-02 02-05-02 Electrical boxes Surveys Conducted by: B Lyons, C Stanley, J. Sullivan, S Cowan & W. Schuck Notes:
Uate: 1-1
-u 7
1o ]2-u0-u]
- 1.
All readings are in jiR/hr taken at the surface. Results are shown in ranges.
- 2. 100% of safely accessible surface area scanned in Section "C" and 10% in Section "D".
- 3. Scan results range from 15-25 p.R/hr.
Suspect Affected Area Unaffected Area Overlap Area Hot Cell Land Section "D" Unaffected Area
-l I
It Figure 9 : Torrey Pines Hillside, Sections A & B, Exposure Rate Measurement Locations and Results Section "A" 18-19 Unaffected Area 19-20 17 Section "B" Unaffected Area Section "B" Suspect Affected Area Ledges Drain Pipes Suspect Affected Area Unaffected Area 2" X2Na 2" X 2" Nal 155190 155594 06-08-02 06-08-02 Surveys Conducted by: B Lyons* C Stanley, J. Sullivan & R. Stowell Dates: 04-09-02 to 04-21-02 i
- 1. All readings are in fiR/hr taken at -1 meter above the surface, shown in ranges.
- 2.
Measurements were taken every 3 meters in unaffected areas and every 2 meters in affected areas.
- 3. Measurements in the drainage ditch were 20-24 pR/hr, maximum measurement outside of the drainage ditch was 21 pR/hr.
Section "B" Unaffected Area zz,..,
Figure 10 : Torrey Pines Hillside, Sections C & D, Fixed Exposure Rate Measurement Locations and Results 17-18 Section "C" Unaffected Area Section "C" Unaffected Area N
S Section "C" Suspect Affected Area
( In Future Report )
Section "B" Unaffected Area 1111 F-]
Riprap Drainage Drainage Ledges Drain Pipes Suspect Affected Area Unaffected Area To Be Covered in future report Overlap Area lnstrumenS, Model Ludlum 3 Ludlum 3 S/N 153551 153590 Probe 2 "X 2" Nal 2" X 2" Nal Probe S/N 155109 155190 Cal Due Date 07-09-02 06-08-02 Electrical boxes Surveys Conjucted by: J. Sullivan & R. Stowell Dates: 04-11-02 to 04-19-02 Notes:
- 1. All readings are in pR/hr taken at -1 meter above the surface, shown in ranges.
- 2. Measurements were taken every 3 meters in unaffected areas and every 2 meters in
- 3. Measurements were13 -21 p.R/hr on the hillside and 22-24 pR/h in thE storm runoff Hot Ceti Land T)
Section "D" Unaffected Area 15-17 FFF
2I
General Atomics' Final Radiological Survey Report For Torrey Pines North Hillside Appendix A Final Survey Plan A-1
Page 1 of 4 August 1, 2001 Revised: April 5, 2002 Prepared By: W. T. LaBonte Approved By:
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L. Q. Gonzales u Final Radiological Survey Plan for Torrey Pines North Hillside Land Area Revision 1 This Final Survey Plan is for Torrey Pines North Hillside Open Land area which 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 the GA Main Site (Torrey Pines Mesa). This land area consists of hillsides with extremely steep slopes and dense ground cover. There are no paved surfaces. This Final Survey Plan is for land surveys only. This plan replaces the plan issued on August 1, 2001.
Due to the difficulty in safely performing surveys as normally performed by GA for land area releases, much of this area was excluded from earlier GA release requests. Namely, LINAC North Land Area, Hot Cell Site, and Torrey Pines Northeast. This land surrounds these parcels of land, and the EA-1 Bunker and TRIGA Reactor Complex Land areas on which Final Surveys have not been completed.
This land area is sub-divided into 4 sections, sections A, B, C, and D, to show relationship to the adjacent land areas and for classification purposes. See figure 1 for location on GA's Main site and figure 2 for the Torrey Pines North Hillside boundary and sub-divisions.
The entire land area is approximately 75,200 ft2 (-7,000 in 2). Section A is approximately 18,300 ft2
(-1700 M 2), Section B is approximately 20,300 ft2 (-1900 m2), section C is approximately 28,500 ft2
(-2,650 M 2), and section D is approximately 8,100 ft2 (- 750 mn 2).
History and Classification Historv There is no known use or storage of radioactive material within this land area, however, elevated activity levels were found, in the soil, in section A, section B and Section C during the performance of the LINAC North Land Area, EA-1 Bunker, and Hot Cell Site Final Surveys. Furthermore, this land area surrounds parcels of land that ranged in classification, (for Final Survey purposes), from Unaffected Areas to Suspect Affected Area. This land area contains many apparent drainage pathways from these land areas as evidenced by erosion gullies.
Classification For consistency reasons, the Torrey Pines North Hillside sections are initially classified with the same Tpn hillsidefinal survey plan wpd A-2
Page 2 of 4 classification as the adjacent land areas.
During the performance of the Final Survey under the original issue of this survey plan, elevated activity levels were found in an approximately 100 ft2 (-9 in2) area in section B, and, elevated exposure rate measurements were obtained in an approximately 50 ft2 (- 5 M2 ) area in section C. These potentially contaminated areas were confined to specific drainage locations and did not represent the entire hillside. The soil with the elevated activity levels in Section B was removed and disposed of as low level radioactive waste.
Due to the extreme difficulties in obtaining measurements during the implementation of the original Final Survey Plan, gardeners were utilized to remove all standing vegetation on the hillside. This not only made a larger portion of the hillside accessible for survey purposes, but allowed the establishment of grids in areas classified as Suspect Affected Areas.
Re-Classification Health Physics determined that the hillside area could be re-classified based on the radiological data collected. As a result, the Suspect Affected Areas were confined to those areas suspected of being contaminated. Radiological data from the rest of the hillside excluded it from this classification. See figure 3 for re-classifications.
Survey Objectives and Responsibility The purpose of performing a final survey is to demonstrate that the radiological conditions within the Torrey Pines North Hillside 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 I.LR/hr above background measured at 1 meter above the surface. Samples will be counted in the Health Physics laboratory (onsite). Surveys will be taken only by qualified Health Physics Technicians having a minimum of 3 years Health Physics Technician experience. 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 1 m above the surface, is less than 10 *tR/hr above L
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:
Tpn hillsidefinal survey plan wpd A-3
Page 3 of 4 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:
C,=
j=-1 Lt 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.
Exposure Rate Measurements
> 25 p.R/hr at surface
> 20 gtR/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 final survey plan.wpd A-4
Page 4 of 4 Unaffected Areas (Sections A, B, C,&D) 4_
54,340- ft2
(-5,050 in2)
No 1 measurement every 3 m, plus 1 at each soil sample location 25% of accessible surfaces "Land Area "Soil Samples (Soil Samples are not required by Site D&D plan)
Take 88 surface (0-6")
samples as indicated in figure 4.
Suspect
- Yes, 1 measurement 100% of Take 44 surface (0-6")
Affected Area, 10m x 10 m every 2 m, plus 1 accessible samples as indicated Section B 4 at each soil sample surfaces on figure 4.
11,700- ft2 location
(- 1,080 m2 )
Suspect
- Yes, 1 measurement 100% of Take 30 surface (0-6")
Affected Area, IOmn x 10 m every 2 m, plus 1 accessible samples as indicated Section C -4 at each soil sample surfaces on figure 4.
- 9100 ft2 location
(- 850 m')
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A-5 TPN final survey plan.wpd I
Figure 1: Torrey Pines (Main) Site Land Areas TORREY PINES NORTH HILLSIDE Bunker Yard Bldg. 21127 HOT Utility Pad
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CELL LAND TORREY PINES NORTHEAST Yard TORREY PINES Reactors
& Land TORREY PINES EAST "TFF UTILITY CORRIDOR CENTRAL TORREY PINES SOUTH A-6 IV S
Figure 2: Torrey Pines North Hillside Land Area Section "C" Unaffected Area
-19400 ft2
-2650m 2
N S
Riprap Drainage Natural Drainage Ledges Drain Pipes Section "C" Suspect Affected Area
( In Future Report)
Section "D"
-8060 ft2
-750m 2
Overlap Area Sectio
-20,3
-189 n -B 41ý 11 looft2 m2ft Hot Cell Land
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-18,280 ft2
-1700m2 IF LINAC North Land
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Section "C" Unaffected Area
-19,400 ft2 Figure 3: Torrey pines North Hillside, Sections and Classifications Riprap Drainage Drainage Section "C" Suspect Affected Area
( In Future Report )
Section "D" Unaffected Area S-8060 ft2 Section "B" Unaffected Area
-4300 ft2 Suspect Affected Area Unaffected Area To Be Covered in future report Overlap Area Section "B" Suspect Affected Area
-11,700 ft2 nTFF Building 22 i
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Section "B" Unaffected Area
-4300 ft 2
Hot Cell Land 7 j
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Ledges Drain Pipes E:71 t'
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- 18,280 ft2
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Torrey Pines Northeast TRIGA Building 21 A-8 Section "A" Suspect Affected Area
-1630 ft' LINAC North Land
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Figure 4: Torrey pines North Hillside, Soil Sample Locations Riprap Drainage Drainage Section "C" Unaffected Area
-19,400 ft2 Section "C" Suspect Affected Area
( In Future Report )
Section "D" Unaffected Area
-8060 ft2 Section "B" Unaffected Area
-4300 ft2 Suspect Affected Area Unaffected Area To Be Covered in future report Overlap Area Section "B" Suspect Affected Area
-11,700 ft2 Section "B" Unaffected Area
-4300 ft2
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Section "A" Unaffected Area
-18,280 ft2
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-1630 ft2 LINAC North Land
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