ML023380559
| ML023380559 | |
| Person / Time | |
|---|---|
| Site: | 07000734 |
| Issue date: | 11/20/2002 |
| From: | Asmussen K General Atomics |
| To: | Adams M, Kwok S NRC/NMSS/FCSS, State of CA, Dept of Health Services |
| References | |
| -RFPFR, 696/CAL-3540 | |
| Download: ML023380559 (59) | |
Text
+ GENERAL ATOMICS November 20, 2002 696/CAL-3540 VIA EXPRESS DELIVERY SERVICE Ms. Mary Adams, Fuel Cycle Licensing (In Duplicate)
Branch/Section 1 U.S. Nuclear Regulatory Commission Mail Stop T-8A33 Two White Flint North 11557 Rockville Pike Rockville, MD 20852-2738
Subject:
Docket No.70-734; SNM-696: Request to Release a Certain Portion of General Atomics' Facility to Unrestricted Use and Delete it from License SNM-696:
Namely, Service Yard of Building 27 and Ms. Sudana Kwok (in Duplicate)
State of California Department of Health Services Radiologic Health Branch Mail Stop 178 601 North 7th Street Sacramento, CA 95814-0208
Subject:
Radioactive Materials License No. 0145-37: Request to Release a Certain Portion of General Atomics' Facility to Unrestricted Use and Delete it from License 0145 37: Namely, Service Yard of Building 27
Dear Ms. Adams and Ms. Kwok:
As you are aware, General Atomics (GA) is continuing its efforts directed at decontaminating, as appropriate, and obtaining the release to unrestricted use of selected facilities and land areas at General Atomics' site in San Diego. GA has recently completed the Final Radiological Survey of the Service Yard of Building 27 (a.k.a. Counting Yard) located on GA's Main Site. This land area is enclosed by a fence and is located immediately adjacent to, and west of, Building 27, which was previously released to unrestricted use (see Figure 1). The total land area requested to be released to unrestricted use is approximately 9,700 ft2 (~900 M2).
The Building 27 Service Yard is an open parcel of land that is, for the most part, paved with asphalt. This parcel of land is enclosed by a chain link fence. There are no sewer lines traversing this land area.
Initially, this land was a parking lot for occupants of Buildings 27 and 27-1. Later, itwas used as a temporary storage area for radioactive materials and supplies used to support Building 27 (Radio-chemistry laboratory) and Building 27-1 (EA-1 Bunker) activities.
During decommissioning activities at GA, this land area was used as a temporary storage area for low level radioactive waste awaiting shipment to an off-site disposal facility, and a portion of this area was used to perform gamma spectroscopy analysis on shipping packages containing low level radioactive waste.
3550 GENERAL ATOMICS COURT, SAN DIEGO, CA 92121-1122 PO BOX 85608, SAN DIEGO, CA 92186-5608 (858) 455-3000
Ms. Mary Adams (NRC) and Ms. Sudana Kwok (State)
November 20, 2002 696/CAL-3540 Page 2 area for low level radioactive waste awaiting shipment to an off-site disposal facility, and a portion of this area was used to perform gamma spectroscopy analysis on shipping packages containing low level radioactive waste.
This area was also used as the "lay-down" area for sections of the EA-1 Bunker Building during it's demolition. The building sections had a fixative (e.g., paint) applied to them while they were in this land area and, then, they were moved to the Nuclear Waste Processing Facility for packaging in preparations for shipment to a low level waste burial site.
Enclosed is GA's report titled "General Atomics' Final Radiological Survey Report for the Building 27 Service Yard." This report documents the results of GA's comprehensive radiological survey measurements and sampling and analyses completed on the Building 27 Service Yard.
These results demonstrate that the Building 27 Service Yard area was decontaminated to levels essentially indistinguishable from normal background and, therefore, the area is well below the NRC-and State-approved criteria for release to unrestricted use.
Accordingly, GA hereby requests the NRC and the State to release the Building 27 Service Yard, as described in the enclosed final survey report, to unrestricted use and delete it from GA's NRC and State of California special nuclear material and radioactive material licenses, respectively. Inasmuch as the NRC was the lead agency for the release of Building 27, GA is requesting that the NRC be the lead agency for this land area.
If you should have any questions regarding this request, or the enclosed report, please don't hesitate to contact 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
Enclosures:
- 1)
Figure 1: Torrey Pines (Main) Site Land Areas
- 2)
GA report titled: "General Atomics' Final Radiological Survey Report for the Building 27 Service Yard," dated November 2002.
cc:
Dr. D. Blair Spitzberg, Chief, NMSS Branch 3, Region IV Mr. Wayne L. Britz, Fuel Cycle Inspector, NRC Region IV Ms. Kathleen Henner, State of CA, Brea, CA Dr. Mina Goeders, State of CA, Brea, CA Ms. Barbara Hamrick, State of CA, Brea, CA
Figure 1: Torrey Pines (Main) Site North Land Areas 11113102 N
Building 27 Service Yard Land Area Bldg. 21/27 Land Hot Cell Site 0
GENERAL ATOMICS' FINAL RADIOLOGICAL SURVEY REPORT For Building 27 Service Yard Land Area Prepared By: William LaBonte, Richard Stowell, Joseph Sullivan and Laura Gonzales Survey Technician: Richard Stowell and Joseph Sullivan Confirmatory Technicians: Scott Cowan and Joseph Sullivan November 2002
+ GENERAL ATOMICS
Table of Contents INTRODUCTION................................................................
I SITE DESCRIPTION.............................................................
1 HISTORY & CLASSIFICATION....................................................
1 H istory..................................................................
1 C lassification..............................................................
2 CRITERIA FOR RELEASE TO UNRESTRICTED USE.................................
2 As Low As Reasonably Achievable (ALARA)....................................
2 Facilities and Equipment (and Asphalt or Concrete Surfaces).......................
2 Release Criteria for Soils.....................................................
3 Exposure Rate Guideline 3
INSTRUMENTATION & BACKGROUND MEASUREMENTS...........................
4 Background Measurements for Instruments/Detectors.............................
4 Background Soil Concentrations of Concern.....................................
4 Exposure Rate Background...................................................
4 FINAL SURVEYS PERFORMED...................................................
5 Objectives and Responsibilities...............................................
5 Survey Plans..............................................................
5 Soil Sam pling.............................................................
6 SURVEY SUM M ARY............................................................
6 RESULTS OF THE FINAL SURVEYS...............................................
7 Scanning.................................................................
7 Fixed M easurements (a and 3)................................................
7 Rem ovable Activity.........................................................
8 Soil Sam ples..............................................................
8 Exposure Rate Scans........................................................
9 Fixed Exposure Rate Measurements...........................................
10 Exposure Rate Measurements at Soil Sampling Locations.........................
10 CONFIRMATORY SURVEYS.....................................................
10 CONCLU SION.................................................................
10 List of Tables Table 1:
USNRC's Acceptable Surface Contamination Levels.........................
T-1 Table 2:
State of California's Acceptable Surface Contamination Levels.................
T-2 Table 3:
Building 27 Service Yard List of Instruments.............................
T-3 Table 4:
General Atomics Gamma Spectroscopy Results of Background Surface Soil Samples.......................................
T-4 Table 5:
Building 27 Service Yard, Soil Sample Results............................
T-7 Table 6:
Building 27 Service Yard, Wipe Sample Results..........................
T-11 ii
List of Fizures (unpaged)
Figure 1: Torrey Pines (Main) Site Land Areas.
Figure 2: Building 27 Service Yard.
Figure 3: Building 27 Service Yard.
Figure 4: Building 27 Service Yard Fixed Measurements and Wipe Locations and Results.
Figure 5: Building 27 Service Yard Alpha and Beta Surface Scan Locations and Results.
Figure 6: Building 27 Service Yard Exposure Rate Fixed Measurement Locations and Results.
Figure 7: Building 27 Service Yard Exposure Rate Scans Locations and Results.
Figure 8: Building 27 Service Yard Soil Sample Locations and Exposure Rate Measurements.
Figure 9: Building 27 Service Yard Remediations.
Appendices Appendix A:
Final Survey Plan, Building 27 Service Yard.
Appendix B:
Confirmatory Survey.
iii
SFinal Radiological Survey Report for the Building 27 Service Yard Land Area Introduction General Atomics (GA) is continuing its efforts directed at decontaminating, as appropriate, and obtaining the release to unrestricted use of selected facilities and land areas at General Atomics. GA has recently completed the Final Radiological Survey of the Building 27 Service Yard (a.k.a.
Counting Yard) located on GA's Main Site. This land area is enclosed by a fence and is located immediately adjacent to, and west of, Building 27, which was previously released to unrestricted use. The total land area to be released to unrestricted use is approximately 9,700 ft2 (-900 m2).
The Building 27 Service Yard Land Area is located on the north portion of GA's Main Site (see Figure 1 and Figure 2). Figure 2 also provides the Building 27 Service Yard site boundary, dimensions, and grid layout for this land area.
This report documents the results of GA's radiological measurements and soil sampling and analysis completed on the Building 27 Service Yard. The results of these surveys and analyses demonstrate that this land area meets the NRC-and State-approved criteria for release to unrestricted use.
Site Description The Building 27 Service Yard is an open parcel of land that is, for the most part, paved with asphalt.
The asphalt has deteriorated in some areas. There is a small strip of unpaved land (soil) along the western boundary of this land area. This parcel of land is enclosed by a chain link fence. There are no sewer lines traversing this land area.
History & Classification History Initially, this land was a parking lot for Building 27 and 27-1. Later, it was used as a temporary storage area for packaged radioactive materials and supplies used to support Building 27 (Radio chemistry laboratory) and Building 27-1 (EA-1 Bunker) activities.
During decommissioning activities at GA, this land area was used for:
- 1.
A "lay-down" area for sections of the EA-1 Bunker Building during it's demolition. A fixative (i.e. paint) was applied to the building sections while in this land area prior to their being moved to the Nuclear Waste Processing Facility for packaging in preparation for shipment to a low level waste burial site.
Page 1 of 10
I ENERALAToMIcs Final Radiological Survey Report for the Building 27 Service Yard Land Area
- 2.
A portion of this area was used to perform gamma spectroscopy analysis on shipping containers filled with low level radioactive waste.
- 3.
For the temporary storage of potentially contaminated materials, such as, soil, and asphalt from other D&D projects prior to packaging as low level radioactive waste for disposal at a licensed burial facility.
- 4.
For the temporary storage of materials removed from the sewer system during remediation, and the packaging of this material as low level radioactive waste for disposal at a licensed burial facility.
During the performance of the final survey, three (3) "Hot Particles" were discovered while performing beta surface scans. The highest measurement was 9800 dpm as measured with a 100 cm2 detector. Gamma spectroscopy analysis of these particles indicated that Cs-137 was the primary isotope. The "Hot Particles" were removed from the asphalt surface and disposed of as low level radioactive waste; all areas were then re-surveyed (see Figure 9). Results after decontamination were at background levels. Soil samples were also collected after decontamination in each of the areas as shown in Figure 9. (Results are provided in Table 5).
Classification Based on the history of use, as identified above, this land area is classified as a Suspect Affected Area for radiological survey purposes.
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" and as far below the approved Soil Release Criteria as reasonably achievable.
Facilities and Equipment (and Asphalt or Concrete Surfaces)
Based on process knowledge, and the gamma spectroscopy results from the Hot Particles, the predominate radionuclide was determined to be Cesium-137. Cobalt-60 was occasionally identified in trace concentrations.
The U.S. NRC's and the State of California's criteria for releasing facilities and equipment to unrestricted use are shown in Tables 1 and 2, respectively. The applicable guidelines for Cs-137 and Co-60 (and most beta/gamma emitters), U-235, U-238 ( and their decay products), are as follows:
Page 2 of 10
+ CENERALAm'MiCs Final Radiological Survey Report for the Building 27 Service Yard Land Area 5,000 dpmrl00 cm 2, averaged over a 1 m2 area 15,000 dpm/100 cm2, maximum in a 100 cm2 1,000 dpmO100 cm, removable activity The applicable guideline for Sr-90, Th-natural, and Th-232 is as follows:
1,000 dpm/100 cm 2, averaged over 1 m2 area 3,000 dpmrl00 cm 2, maximum in a 100 cm 2 area 200 dpm/100 cm, removable activity Release Criteria for Soils The predominant radionuclides found in the soil at GA and the approved release criteria in pCi/g (above natural background concentrations) for these radionuclides are provided as follows:
Enriched Uranium (U-234 + U-235) 30 pCi/g Thorium (Th-228 + Th-232) 10 pCi/g Depleted Uranium 35 pCi/g Cs-137 15 pCi/g Co-60 8 pCi/g Sr-90 1800 pCi/g If more than one radionuclide exists, the sum of the fractions of the concentrations is calculated as follows:
a=1 L 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.
Page 3 of 10
+.CENE-RALAroIcs Final Radiological Survey Report for the Building 27 Service Yard Land Area Instrumentation and Background Measurements A list of instruments used to conduct the radiological surveys documented in this report is shown in Table 3. The table includes: (1) a description of the instrument, model number and its serial number, (2) a description of the detector (if applicable) and its serial number, (3) instrument ranges, (4) calibration due dates, (5) typical background readings and (6) calibration efficiencies (if applicable).
All of the instruments used were calibrated semiannually and after repair, except for exposure rate meters which were calibrated quarterly.
Background Measurements for Instruments/Detectors Building 13 on GA's main site was used for conducting background measurements with instruments used for the final survey because: (1) there is no history involving radioactive materials or storage of radioactive materials in Building 13, and (2) the various surfaces and construction materials found at the Building 27 Service Yard Land Area could also be found within and outside of Building 13.
Background information, where appropriate, is included in Table 3.
Minimum detectable activities (MDA's) for instruments used for fixed measurements, for each type of surface (see Table 3), were calculated using equation (5-2) from the NUREG/CR-5849 as shown below:
Equation (5-2)
MDA = 2.71+4.65 (dpmlOOcm 2)
A txEx-A 100 Where:
B R =background rate (cpm) t = count time (min)
E = efficiency A = area of the detector (cm 2)
Background Soil Concentrations of Concern Typical background concentrations measured by gamma spectroscopy in soil near the GA site have been established (at the 95% confidence level) and are provided in Table 4; footnotes to Table 4 provide the locations where these samples were collected.
Exposure Rate Background Typical exposure rate background for GA's site using a Ludlum Model 19 micro R meter is 12-18 [tR/hr measured at 1 m from the surface of soil. This range of exposure rates can be measured Page 4 of 10
+ cENEiRALATOmIcs Final Radiological Survey Report for the Building 27 Service Yard Land Area south of Building 15 (an office building on the eastern portion of the GA site). Measurements taken offsite in 10 different locations (9 offsite and 1 onsite at a non-impacted area near Building 15) over a period of 15 months also averaged - 15 [.R/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 surface are typically higher than measurements taken on soil due to the higher concentrations of naturally occurring radioactive material (NORM) in the asphalt. This background fluctuates depending upon the asphalt batch used and the date applied.
An exposure rate background survey, (measured at 1 m from the surface), was performed at many non-impacted asphalt surfaces on the GA site using the same 2" x 2" NaI(TI) detector used to perform the exposure rate surveys for the Building 27 Service Yard Land Area. The exposure rates ranged from 11-19 [iR/hr measured at 1 m from the asphalt surface. This is the most appropriate background for comparison with readings from this land area.
Final Surveys Performed Objectives and Responsibilities The objectives of the final survey plans were: (1) to demonstrate that the average surface contamination levels for each survey unit were below the approved release criteria, (2) to show that the maximum residual activity did not exceed three times the approved release criteria for average surface contamination value in an area up to 100 cm2, (3) to demonstrate soil sample results at the surface were well below GA's approved release criteria for unrestricted use, and, (4) that the exposure rate measurements taken in these areas, measured at 1 meter above the surface, were less than 10 [tR/hr above background.
Survey Plans Final Survey Plans were developed based on the previous history of the adjacent Buildings and the Building 27 Service Yard Land Area itself, the radionuclides of concern for this area, the potential for contamination, the various types of surfaces encountered and the classification of the various areas. See Appendix A for Final Survey Plan for the Building 27 Service Yard Land Area.
Surveys were taken in accordance with the approved survey plan 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 Page 5 of 10
C+GrAIEHALArOmIcs Final Radiological Survey Report for the Building 27 Service Yard Land Area model and serial number of both the ratemeter and detector), calibration due date, % efficiency, background readings (if applicable) and any other pertinent information.
Soil Sampling Soil samples were collected at the locations as indicated on Figure 8.
Each of the soil samples taken was approximately 1 kilogram in mass. The sampling locations were documented on a drawing. The samples were properly logged, labeled, tracked and packaged into plastic bags. All debris (i.e., grass, rocks, sticks, asphalt and foreign objects) was removed from each sample. Each soil sample was individually crushed to reduce large lumps, dried, placed into tared marinelli beakers (filled-to the top), weighed, sealed and transported to GA's Health Physics Laboratory.
Soil samples were analyzed in GA's Health Physics Laboratory with a Canberra Low Sensitivity Gamma Spectroscopy MCA System using a high purity germanium detector. The system is calibrated using NIST traceable standards and performance checked daily. Soil samples were counted for a minimum of 30 minutes each. A 30 minute count was sufficient to detect the radionuclides of concern at levels below GA's approved soil release criteria.
Survey Summary Comparisons of the Site Decommissioning Plan requirements with zhe Final Surveys performed in relation to the percentage of surface area scanned, number of measurements (i.e., number of fixed radiation measurements), exposure rate measurements (PR/hr) and soil samples taken are provided as follows:
Page 6 of 10
+, GENERA.ArOmtcs Final Radiological Survey Report for the Building 27 Service Yard Land Area D-Plan = GA Site Decommissioning Plan The total surface area to be released is approximately: 900 m2.
Results of the Final Surveys The results for the Building 27 Service Yard Land Area Final Surveys are provided in figures and tables as noted below:
Scanning 100% of the asphalt surface was scanned for a and 03 activity with large area (434 cm 2) gas flow proportional detectors held within approximately 1" of the surface. All gross activity measurements (a= 10 - 40 counts/minute, P3= 1800 - 2800 counts/minute) were at typical background levels. See Figure 5 for a and P3 survey locations and results.
Fixed Measurements (a and 13) 80 fixed a and 80 fixed P3 measurements were taken on asphalt surfaces. The highest a measurement
(< 20 cpm) was typical of background readings (< 20 counts/minute). All results were less than the minimum detectable Activity (MDA) of 216 dpm/100 cm 2.
Page 7 of 10 Comparisons of Site Decommissioning Plan Requirements with Final Survevs Performed on the Building 27 Service Yard Land Survey Area**
Gridding
- of Direct
- of Exposure Surface Scans
- of Soil Samples Measurements Rate (tRI/hr) on asphalt Fixed a, P3, or Measurements wipes on asphalt (I m from surface)
D-Plan*
Yes 1 per 4 mr, or, I per 4 m2, or, 100% of surfaces 4 per lOin x 1Om Suspect Affected 1 every 2 in I every 2 m.
grid. Total = 36 Area based on - 900 m2
-+
Total = 225 Total = 225 Surveys Yes Fixed a = 80, At least I every 2 in 100% of surfaces 54 surface (0-6") &
performed in 10m x 10m Fixed 13 = 80, Total = 240 for a and 100%
6 sub-surface Suspect Affected grids Wipes = 80, of surfaces for fI (6"-12") samples Areas 4
Plus 54 surface and Total = 60 Total = 240 1 m measurements at each soil sample location
I CENERALAromIrCS Final Radiological Survey Report for the Building 27 Service Yard Land Area The highest P3 measurement was 1198 cp2minutes (gross counts), which is typical of background readings of 1220 +/- 170 cp2minutes. All P3 measurements were less than the MDA of 236 dpm/100 cm2. See Figure 4 for results and locations.
All measurements were not discernable from background levels and were well below the approved release criteria for Cs-137, Co-60, U-235, U-238, Th-natural, Th-232, and Sr-90.
Removable Activity 80 wipe samples were taken on asphalt surfaces and analyzed in the GA Health Physics laboratory for a and P activity. The highest a result was <20 dpm/100 cm2, the highest P3 result was <20 dpm/100 cm2. See Figure 4 for locations and Table 6 for results.
All results were at typical of background levels and well below the approved release criteria for Cs 137, Co-60, U-235, U-238, Th-natural, Th-232, and Sr-90.
Soil Samples A total of sixty (60) soil sample were taken. Ten (10) surface (0-6") soil samples were taken from the unpaved area on the western boundary, four (4) from soil accumulated on the eastern boundary which was later moved to the western boundary to accommodate direct surveys, forty (40) soil samples were taken 0-6" beneath the asphalt layer, and six (6) soil sample were taken 6"-12" beneath the asphalt layer. See Figure 8 for approximate locations and Table 5 for results. The results presented in Table 5 are summarized below:
______Radionuclide Concentration (pCi/g)____
238U 235U 137 Cs 22 8Th(2 12 Pb) 23 2Th(228Ac) 60CO High 3.38 +/- 2.85 0.27 +/- 0.09 0.47 +/- 0.08 1.99 +/- 0.27 2.31 +/- 0.41 0.17 +/- 0.08 Low ND ND ND 0.45 +/- 0.30 0.66 +/- 0.16 ND Average 1.40 0.15 0.13 1.44 1.70 0.16 (N=60)
See Table 4 for background ranges, and locations where background samples were taken.
Notes: 1. ND means not detected.
- 2. Average Minimum Detectable Activity (MDA):
U-238 = 1.58 pCi/g (63 keV peak)
U-235 = 0.14 pCi/g (186 keV peak)
Cs-137= 0.13 pCi/g (662 keV peak)
Page 8 of 10
+
+EANrFLmarmIcs Final Radiological Survey Report for the Building 27 Service Yard Land Area Co-60 = 0.16 pCi/g (1173 keV peak)
Th-228 = 0.21 pCi/g (238 keV peak)
Th-232 = 0.43 pCi/g (911 keV peak)
- 3. The high concentrations for each isotope did not occur in the same sample.
- 4. No sample had a sum of fractions greater than 1.0.
- 5. The Average Activity is based on the numerical average of all (60) samples, using the Average MDA value when the isotope was not detected.
- 6. Background is not subtracted. See Table 4 for soil background information.
- 7. Soil sample locations are illustrated in Figure 8. Soil sample results are presented in Table 5.
The results of soil samples # 20, 30, & 40 collected in the remediated areas (see Figure 9) were not discernable from natural background levels. (See Table 5).
Uranium (U-238 and U-235) was at, or near, nominal background levels and well below the approved release limits.
Cs-137 was detected in only twelve (12) out of sixty (60) soil samples i.e. in 20% of the samples as compared to being detected in nine (9) out of thirty (30), or 30% of the background samples. The highest activity level was 0.47 +/- 0.08 pCi/g, which is within the statistical range of the highest background soil sample of 0.31 +/- 0.08 pCi/g and is far below the approved release limit of 15 pCi/g.
Thorium contamination was not present (as determined by process knowledge and gamma spectroscopy analyses of soil samples). All thorium results were at, or near, background levels and well below the release limit of 10 pCi/g.
Co-60 was detected in one (1) soil sample at 0.17 +/- 0.08, which is slightly above the minimum detectable activity (0.16 pCi/g) for the highly sensitive equipment used. This activity level is far below the approved release limit of 8.0 pCi/g.
Exposure Rate Scans 100% of the area was scanned with a NaI(T1) detector held approximately 1" from the surface. The exposure rate ranged from 14 to 21 pR/hr. Natural background is typically 17-19 pR/hr for exposure rate scans at V" from the surface. See Figure 7 for locations and results.
Page 9 of 10
.+CENERALATOMICS Final Radiological Survey Report for the Building 27 Service Yard Land Area Fixed Exposure Rate Measurements Fixed exposure rate measurements were taken in 240 locations at 1 meter from the surface The exposure rate measurements ranged from 14 to 19 tR/hr on asphalt. See Figure 6 for locations and results. These measurements are not discernable from natural background levels and are well below the approved release criteria of 10 [pR/hr above background.
Exposure Rate Measurements at Soil Sampling Locations Exposure rate measurements were taken at contact with and Im from the surface at 54 soil sample locations. These measurement results are all at natural background levels. The highest measurement was 19 pR/hr at contact and 19 ptR/hr at 1 m; as compared to a natural background range of 17-19 piR/hr at contact and 11-19 pR/hr at I m (asphalt). See Figure 8 for soil sample locations and results.
Confirmatory Survey Following the completion of the Final Survey, a Confirmatory Survey was performed by GA HP technicians. The internal Confirmatory Survey was conducted in accordance with an approved survey plan.
All measurements were in agreement with the final survey results and all measurements were at or near natural background levels, and, thus, well below the applicable release criteria. See Appendix B for details.
Conclusion Final contamination and radiation surveys, as well as the results of analyses of soil samples, as documented in this report, demonstrate that the Building 27 Service Yard Land Area meets the approved criteria for release to unrestricted use. The final survey results were not discernable from normal background levels.
Page 10 of 10
,w, 1i YT TTIIC
A £NN1TVT A TT T1 'TTTT'
A £'F' f'fT'r1 A P. NTP.T A 7I'TdT 1 T'7T'T C I
T-1 Nuclides
.Averageb*.
Maimumm4 '
,Removableb
<I (dpnm/lOnm p
- 2)
(dlxlOO cm2))
(dpm1OOcm).
U-nat, 235U, 238U, & associated decay products 5,000 (x 15,000 a 1,000 a Transuranics, 226Ra, 228Ra, 23 0Th, 228Th, 23 1Pa, 227Ac, 100 300 20 1251, 1291 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 'Sr 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 cm2 and 1.0 mRad/hr at 1 cm2, respectively, measured through not more than 7 milligrams per square centimeter of total absorber.
STnhl* *_,qTATF., OF CA ACCEPTABLE SURFACE CONTAMVINATION LEVELS '
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 Nuclides' Averageb,4 Maximuml)dI Removableb-'
(dpni/100cm')
(dpmn1O0cm 2)
(dpm/I00cm2 )
U-nat, 235U, 238U, & associated decay 5,000 15,000 1,000 products Transuranics, 226Ra, 228Ra, 230Th, 228Th, 100 300 20 23 1Pa, 227Ac, 1251, 1291 Th-nat, 232Th, 9OSr, 2 23Ra, 224Ra, 232 U, 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 9"Sr and other noted above
I--
F_-
F.
1" -"
I' --
F
(-7 r-I-
I IF r-F....
r---
Table 3: Building 27 Service Yard List of Instruments Instrument Detector Range (cpm)
Calibration Efficiency Typical Background Description Due Date Ludlum Ludlum Model 43-37 gas Four Linear Ranges (asphalt)
Active Probe Area = 434 cm 2. The detector and rate meter Model 2221 proportional (434 cm 2) 0-500,000 & one Log 11-12-02 21 09%
10-40 cpm are combined and mounted on a roll around cart. The SIN148425 Alpha detector 50-500,000 instrument features a static-flow system, quick connects, a S/N 086236 portable gas bottle and a means to adjust the height of the detector from the floor for optimum performance Ludlum Ludlum Model 43-37 gas Four Linear Ranges (asphalt)
Active Probe Area = 434 cm2. The detector and rate meter Model 2221 proportional (434 cm 2) 0-500,000 & one 11-13-02 28.34%
2400-2800 cpm are combined and mounted on a roll around cart. The SIN 154202 Beta detector Log 50-500,000 04-01-03 30 17%
instrument features a static-flow system, quick connects, a S/N 149017 portable gas bottle and a means to adjust the height of the detector from the floor for optimum performance.
Ludlum Ludlum Model 43-68 Four Linear Ranges (asphalt) 100 cm 2 gas flow proportional counter.
Model 2221 100 cm 2 proportional 0-500,000 & one Log 01-23-03 3495%
1220 +/- 170 cp2m SIN 86302 Beta detector 50-500,000 MDA = 236 dpm/100 cm2 (asphalt)
SIN 142547 Ludlum Ludlum Model 44-10 Five Ranges (asphalt) 2 inch x 2 inch Nal (TI) scintillator. Used for initial survey Model 3 Na! (TI) Scintillator 0-500 piR/hr 09-13-02 N/A 17-19 t.R/hr contact on ground floor and for measuring external dose rates on the SIN 153311 Gamma detector 12-11-02 11-19 pR/hr @ I m surface and at one meter.
SIN 155594 Ludlum Ludlum Model 43-65 Four Ranges (all)
Active Probe Area = 50 cm 2 Model 12 Alpha Scintillator 0-500,000 02-22-03 21.77%
0-20 cpm SIN 91051 ZnS(Ag) SIN 094053 MDA = 216 dpm/l00 cm2 (all)
Canberra Gas Flow Proportional Canberra Model 2404 Low Level a/P gas proportional Low Level Detector N/A As needed 30%
Vanes with Sample counting system used to count wipes for removable c./P Counter contamination. Results are usually reported as dpm/100 cm 2.
Model 2404 Canberra Gamma High Purity Vanes with Gamma Spectroscopy MCA system using a high purity Spectroscopy Germanium Detector N/A As needed Sample Varies with Sample Germanium detector.
System T-3
v--r---
FV-r..
r
-'r F-m
---7 r--nrn m--
7-F-
-- l-rF Tablek; General Atomics Gamma Spectroscopy Results ofBackground Surface Soi Samples K
A"' ~t< A 2
~
4' Sptembeir 24,12002 "4
Co....Th_:137 6
2i 2 2 8 Ra 2 Tb)
(Total)Tb 2 38 T5f Energy Peaks 6616 keV 1173 keV,.
-238 keVx'-
911 keVY 4.
Th+
2T 6.(2 144 (186) keV 4..'
4" 23 keV
(
,;b,
, (~'Ac)
.3 (6)Tli) l SampleID
£i*?
£ ionucli oncentati6Ons (ig)
-Rýeislts +/- 26;30 Minute Counts Samples collected June, 2000 Re-analy7ed November, 2001 X-I ND' ND 0.49 +/- 0.15 1.25 +/- 0.34 1.74 t 0.48 ND ND X-2 ND ND 0.91 +/-0.23 0.91 +/-_0.23 1.81 +/-_0.46 1.17 +/- 1.13 (009-+/-005)
X-3 ND ND 1.40 +/- 0.27 1.79 +/- 0.37 3.19 +/- 0.63 1.51 +/- 1.20 (0.09 +/- 0.09)
X-4 0.08 +/- 0.07 ND 1.71 +/- 0.31 2.08 +/- 0.47 3.78 +/- 0.78 ND (0.18 +/- 0.13)
X-5 ND ND 1.52 +/- 0.29 2.83 +/- 0.70 4.35 +/- 0.99 ND (0 20 +/- 0.15)
X-6 ND ND 1.14 +/- 0.32 1.12 +/- 0.26 2.25 +/- 0.58 ND (0.09 +/- 0.05)
X-7 0.11 +/- 0.07 ND 1.68 +/- 0.24 2.18 +/- 0.47 3.86 +/- 0.71 ND (0.22 +/- 0.10)
X-8 ND ND 2.32 +/- 0.38 2.14 +/- 0.54 4.45 +/- 0.92 ND (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-11 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+/--005)
I ND = Energy peak not identified T-4
r--
F r-v
- r...
r--
r r
r r
r
-r r:
r nI Table.4, (continued:G ener'al`AtomisGamma Spectroscopy Res ackground SurfaceSd Sam isl Table ~ ~ ~
~
~
~
~
~
~
~
~
~
~~~e 4ecniud:Gnml trisG
~
~
,~'
~:
7>~trber 24, 2002
..*++* **+
'*7.:".'P.,>".
.'>+ ++ +.
+
+ '" *
"++'
'+'!*
- ++'**+ ++ "
+
'+*'t
.7,+
' +
+ ;Z > '
+ /"
- +
- A...
- % +*
A<*
)6 22Rja 23 Th1 2
(Total) +
--235 2 2 8Th 28f' Energy Pt&
661.6 keV 1173 keV 238 keY 911 ke2 8:,,
iu-232' 63.392.7) k
'144 (186),ke+,
_____Q'Pb),
(Iý4h Sample "ID`Radzonuclhde Concentrations ( pci/g)-Results+/- 2o-30 Minute Counts X-14 ND ND 1.42 +/- 0.19 1.59+/- 0.29 3.01 +/-_0.48 0.67_+/-0.71 (0.11 +/-_005)
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 t 0.29 1.36 +/- 0.28 2.80 +/- 0.57 1.52 +/- 1.26 (0.19 + 0.08)
X-26 ND ND 1.81 +/-.0.24 1.41 +/--0.31 3.22-+/-0.54 0.68 +/- 0.96 (0.13 +/-_0.06)
X-27 ND ND 1.65 +/- 0.20 2.00 +/- 0.34 3.65 +/- 0.54 ND (0.15 +/- 0.07)
X-28 ND ND 1.40 +/- 0.20 1.47 +/- 0.33 2.87 +/- 0.54 1.35 +/- 1.03 (0.28 +/- 0.07)
X-29 0.01 +/- 0.07 ND 0.81 +/- 0.17 1.61 +/- 0.34 2.42 +/- 0.51 ND (0.09 +/- 0.06)
X-30 ND ND 1.90-+/-0.22 1.88 +/-0.33 3.79_+/-0.55 2.67-+/-1.79 (0.35-+/-0.11)
T-5
F----
F-( --
F-V -
F-.....
r r
r-r
n
r f-F ----
F--
I---
Table 4 (continued): General Atomics Gamma Spectroscopy Results of Background Surface Soil Samples September 24, 2002 Sample Locations:
XI Sorrento Valley Road near sample location ST65 on the hillside -I mile from Building 37.
X2 Sorrento Valley Road near Carmel Mountain Road junction on steep cliff.
X3 Sorrento Valley Road in Los Penasquitos Preserve -2 miles from Building 37.
X4 Sorrento Valley Court at the end of the road in the field.
X5 Roselle Street, East of sample location ST64 - '/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 '/2 miles from Building 37 (collected on the hillside).
X8 Vista Sorrento Parkway, - / mile from Building 37 (collected on the hillside).
X9 Callahan Road, -
'/2 mile from Building 37 (collected on the hillside).
X10 Eastgate Mall road, -3 miles from Building 37 (collected in a field).
X1I 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
r F
F r F
F -
F-- F---
I-F-
Table 5: Gamma Spectroscopy Results of Building 27 Service Yard Land Area Soil Samples 13'Cs 60Co 22$Th 228Ra ("* Th)
(rot"a) Th bRU 3SU Energy Peaks 661.6 keV 1173 keV 238 keV 911 keV 22 8Th +232Th 63.3 (92.7) keV 144 (186) keV
_____,__(21_2 Pb)
(22 Ac)
( 234Th)
Sample ID Radlonuclide Concentrations (pCl/g) - Results +/-- 20r-30 Minute Counts - Backgrounds Not Subtracted All samples are surface, 0-6", except "A" samples which are subsurface, 6-12".
I ND' ND 1 49+/--0.28 1.65+/--0.30 3.154-058 0.394-0.60 (0.15+/-0.07) 2 0.07 +/- 0.06 ND 1.63 +/- 0.20 1.72 +/- 0.31 3.34 +/- 0.51 1.13 +/- 1.01 (0 20 +/- 0 09) 3 ND ND 0 45 +/- 0.30 0.66 +/- 0.16 1.11 +/- 0 46 ND (0.05 +/- 0.06) 3A ND ND 1.14 +/- 0.15 1.57 +/- 0.42 2.71 +/- 0.57 ND (0.12 +/- 0.06) 4 ND ND 1.66 +/- 0.20 1.64 +/-h 0.49 3.30 +/- 0.69 ND (0 12 +/- 0 08) 5 ND ND 1.27 +/- 0.21 2.20 +/- 0.39 3 46 +/- 0.59 ND (0.18 +/- 0.10) 6 ND ND 1 63 +/- 0.20 1.84+/--0.36 3.47 +/-0.56 1.21 +/- 1.26 (0.19+/--0.08) 7 ND ND 1.62 +/- 0.21 2.06 +/- 0.49 3.68 +/- 0.70 ND (0.20 +/- 0.12) 8 ND ND 1.70 +/- 0 32 1.55 +/- 0.35 3.25 +/- 0.67 1.39 +/- 1.21 (0.12 +/- 0.26) 9 ND ND 1.60 +/- 0.30 1.80 +/- 0.19 3 40 +/- 0.50 ND (0.12 +/- 0 08) 9A ND ND 0.95 +/- 0.13 1.35 +/- 0.33 2.30 +/- 0.45 1.24 +/- 1.22 ND 10 ND ND 1.83 +/- 0.25 1 65 + 0.31 3.48 +/- 0.56 ND (0.15 +/- 0.07) 11 ND ND 1.26 +/- 0.25 1.27 +/- 0.29 2.53 +/- 0.54 ND (0.13 +/- 0.06) 12 ND ND 1.62+/-0.32 1.94+/--0.35 3.56++/-0.67 0.90+-0.95 (0.27+/--0.09)
ND =Not Detected, energy peak not identified.
T-7 F--
F-..
F K
t F
V
[7
r_--
- r F-I-v---
[-"
Table 5 (continued): Gamma Spectroscopy Results of Building 27 Service Yard Land Area Soil Samples "13 7Cs 6Co 2"Th 223Ra (f2 Th)
(rotu') Th 2sU 23u Energy Peaks 661.6 keV 1173 keV 238 keV 911 keV 223th + 232Th 63.3 (92.7) keV 144 (186) keV
-_11 I
( 212 Pb)
( 22 Ac)
( 2 4Th)
Sample ID Radionuclide Concentrations (pCilg) - Results +/- 2o-30 Minute Counts - Backgrounds Not Subtracted "All samples are surface, 0-6", except "A" samples which are subsurface, 6-12".
13 ND ND 1.74 +/- 0.22 2.15 +/- 0 51 3.89 +/- 0.73 ND (0.19 +/- 0.11) 14 ND ND 1.62 +/- 0.20 1.78 +/- 0.42 3.40 +/- 0.62 ND (0.20 + 0 07) 15 ND ND 1.57 +/- 0.20 2.12 +/- 0.49 3.69 +/- 0.69 ND (0.14 +/- 0.08) 16 ND ND 1.76+/-0.21 1.91 +/-0.40 3.67+/-0.61 0.88+/- 1.18 (0.18+/-0.08) 17 ND ND 1 52 +/- 0.19 1.76 +/- 0.46 3.27 +/- 0 65 2.02 +/- 1.47 (0.11 +/- 009) 18 ND ND 1 64 +/- 0.30 1.75 +/- 0.34 3.38 +/- 0 65 1.23 +/- 0.92 (0.14 +/- 0 06) 19 ND ND 1.74 +/- 0.38 2.14 +/- 0.40 3.88 +/- 0.77 0.75 +/- 1.19 (0.13 +/- 0.08) 20 ND ND 1.79 +/- 0 33 2.25 +/- 0.41 4.04 +/- 0.75 0.55 +/- 0.93 (0.17 +/- 0.10) 21 ND ND 168+/-0.30 1.79+/--0.34 3.47+/-0.64 0.55+/--0.83 (0.16+/--0.09) 22 ND ND 1.75 +/- 0.33 1.94 +/- 0.35 3.68 +/- 0.67 1.11 +/- 1.03 (0.13 +/- 0.08) 23 0.08+/--0.07 0.17+/-0.08 1.37+/-0 18 1 88+/-0.38 3.24 +/- 0.56 ND (0.17+/--0.09) 24 ND ND 1.72+-032 1.92+/-0.35 3.64+/-068 0.86+/- 1.00 (0.18+/-007) 25 ND ND 1.56 +/- 0 36 1.96 +/- 0.42 3.53 +/- 0.78 ND (0.19 +/- 0.13) 25A ND ND 1.21 +/- 0.15 1.71 +/- 0.35 2 92 +/- 0.50 ND (0.12 +/- 0.07) 26 ND ND 1.43 +/- 0 27 1 55 +/- 0.29 2.99+/- 0.56 ND (0 15 +/- 0.07) 27 ND ND 1 76+/--035 231 +/--041 407+/--0.76 ND (0.12 +/- 0 08)
T-8 If--
I---
F--_
I --
(-- "
- 1--
-
[
t
( -
U7 U71 fl
(--.~ F-. r--
I -
f--
F---
F-- -
(--
Table 5 (continued): Gamma Spectroscopy Results of Building 27 Service Yard Land Area Soil Samples 13'Cs 60Co 2 8ThI 228Ra (232 Th)
(lot23) Tb U5U Energy Peaks 661.6 keV 1173 keV 238 keV 911 keV 228Th + 232Th 63.3 (92.7) keV 144 (186) keV so_(
212 Pb)
( 229 Ac)
(23Th)
Sample ID Radionuclide Concentrations (pCi/g) - Results + 21-30 Minute Counts - Backgrounds Not Subtracted All samples are surface, 0-6", except "A" samples which are subsurface, 6-12".
27A ND ND 1.30 +/- 0.17 1.56 +/- 0 30 2.85.+ 0.47 0.60 1 01 (0.15 +/- 0.08) 28 ND ND 1.49+0.18 1.6010.34 3.094-0.53 1.24+L 1.23 (0.18+-008) 29 ND ND 1.10 +/- 0.14 1.18 +/- 0.29 2.29 + 0.43 ND (0.21 +/- 0.09) 30 ND ND 1.64 +/- 0.33 1.60 +/- 0.39 3.24 + 0.72 ND (0.20+/- 0.09) 31 ND ND 1.33 +/- 0.30 1.67 + 0.37 3.00+/- 0.67 ND (0.12 + 0.10) 32 ND ND 1.74+0.21 1.74+/--0.31 3.48-0.51 0.73+-0.80 (0.19+-0.07) 33 ND ND 1.14 10.21 1.92+/- 0.47 3.06 0.68 ND (0.18 +/- 0.07) 33A ND ND 1.07 +/- 0.16 1.42 +/- 0.31 2.49 0.47 ND (0 09 + 0.07) 34 ND ND 1.55 +/- 0.27 1.71 +/- 0.34 3.26+ 0.60 ND (0 11 + 0 06) 35 ND ND 1.75 1 0.36 2.12 +/- 0.42 3.87 + 0.78 ND (0.12 +/- 0.08) 35A ND ND 1 39+-0.20 1.61 +-0.38 3 00+-058 0.66++/- 1.27 (0.17+-0.11) 36 ND ND 1.19 +/- 0.16 1.43 + 0.29 2.62 +/- 0.45 ND (0.13 + 0.06) 37 ND ND 1,33+0.17 1.76+/--0.32 3.09+ 0.49 1.17 + 1.30 (0.20+ 0.08) 38 ND ND 1.53+-0.19 1.78+/--036 3.31 +-0.55 1.17 +/- 1.02 (0.22+-0 10) 39 0.25 +/- 0.08 ND 123 +/- 0 18 1.56 +/- 0.34 2.79 + 0 52 ND (0.11 + 0.10) 40 ND ND 1.99 +/- 0.27 1.82 +/- 0 36 3.81 4+ 0 63 1.11 + 1.41 (0.22 +/- 0 08)
T-9
[F--"
F---
I r--
1(--
Table 5 (continued): Gamma Spectroscopy Results of Building 27 Service Yard Land Area Soil Samples 13Cs 60 Co 228Th 22"Ra (23 Th)
(Tota) T-i.
U 235U Energy Peaks 661.6 keV i173 keV 238 keV 911 keV 225Th + ulTh 63.3 (92.7) keV 144 (186) keV
-- 40-_
( 212 Pb)
( 221 Ac)
I (234Th)
Sample ID Radionuclide Concentrations (pCi/g) - Results + 2c-30 Minute Counts - Backgrounds Not Subtracted
" All samples are surface, 0-6", except "'A" samples which are subsurface, 6-12".
41 ND ND 1.35+0.23 2.13 +/- 0.42 3.49 +/- 0.65 3.38 +/- 2.85 (0.15 +/- 0.06) 42 0.38 +/- 0.08 ND 1.39 +/- 0.18 1.28 +/- 0.34 2.67 +/- 0.52 ND (0.15 +/- 0.07) 43 ND ND 1.27+/--022 2.00+0.39 3.26+/--0.61 3.16+/--2.66 (0.14+/--0.06) 44 0.47 +/-0.08 ND 1.23+0.29 1.27+/--0.29 2.50+/-0.58 1.17 +/- 1.12 (0.14+0.07) 45 0.32 +/-.0.11 ND 1 05 +/- 0.19 1.58 +/- 0.42 2.63 +/- 0.61 ND (0 09 +/- 0.09) 46 0.16 +/- 0 06 ND 1.34+025 1.38 +/- 0 29 2.72 +/- 0.55 1.63 +/- 1.43 (0.11 +/- 0 05) 47 ND ND 1.11 +/- 0.20 1.67 +/- 0 42 2.78 +/- 0 62 ND (0.11 +/- 0.10) 48 0.14 +/- 0.07 ND 1 09 +/- 0.23 1.26 +/- 0.28 2.35 +/- 0.51 1.52 +/- 131 (0.12 + 0.06) 49 ND ND 147 +/- 0.36 1.62 +/- 0.43 3.09 -h 0 78 ND (0 07 + 0 09) 50 0.06+/-0.05 ND 0.96 +/- 0.13 1 04 +/- 0 27 2 0010 40 ND (0.10 +/- 0.08) 51 ND ND 1 29+0.17 1.90 +/- 0.36 3.19:- 0 53 0.36 +/- 0 94 (0 11 +/- 0.11) 52 0.43 +/- 0.09 ND 1.42 +/- 0.20 1.18 +/- 0.29 2.60 +/- 0.49 ND (0.13 +/- 0 07) 53 0.16 +/- 0.07 ND 1.47 +/- 0 19 1.72 +/- 0.38 3.19 +/- 0.57 ND (0.12 +/- 0.07) 54 0.20+/-1006 ND 1 50 +/- 0.19 1.45+/- 0.32 2.95 +/- 0 51 ND (0.15 +/- 0.08)
Range1 (Min - Max)
ND - 0.47 ND - 0.17 0.45-1.99 0.66-2.31 1.11 -4.07 ND - 3.38 ND - 0.27 T-10 I -
[ --I-F f
I F....
( -.--
F-F-'-
Table 6: Building 27 Service Yard Land Area Wipe Survey Results Sample a Activity in P Activity in Sample a Activity in P Activity in Number dpm/l 00cm 2 dpm/1 00cm 2 Number dpm/1 00cm 2 dpm/1 00cm 2 Asphalt Surface (Figure 4) 1
<20
<20 23
<20
<20 2
<20
<20 24
<20
<20 3
<20
<20 25
<20
<20 4
<20
<20 26
<20
<20 5
<20
<20 27
<20
<20 6
<20
<20 28
<20
<20 7
<20
<20 29
<20
<20 8
<20
<20 30
<20
<20 9
<20
<20 31
<20
<20 10
<20
<20 32
<20
<20 11
<20
<20 33
<20
<20 12
<20
<20 34
<20
<20 13
<20
<20 35
<20
<20 14
<20
<20 36
<20
<20 15
<20
<20 37
<20
<20 16
<20
<20 38
<20
<20 17
<20
<20 39
<20
<20 18
<20
<20 40
<20
<20 19
<20
<20 41
<20
<20 20
<20
<20 42
<20
<20 21
<20
<20 43
<20
<20 22
<20
<20 44
<20
<20 T-1I
Table 6 (continued): Building 27 Service Yard Land Area Wipe Survey Results Sample a Activity in P3 Activity in Sample a Activity in P3 Activity in Number dpm/100cm2 dpm/1OOcm 2 Number dpm/100cm2 dpm/1OOcm 2 Asphalt Surface (Figure 4) 45
<20
<20 63
<20
<20 46
<20
<20 64
<20
<20 47
<20
<20 65
<20
<20 48
<20
<20 66
<20
<20 49
<20
<20 67
<20
<20 50
<20
<20 68
<20
<20 51
<20
<20 69
<20
<20 52
<20
<20 70
<20
<20 53
<20
<20 71
<20
<20 54
<20
<20 72
<20
<20 55
<20
<20 73
<20
<20 56
<20
<20 74
<20
<20 57
<20
<20 75
<20
<20 58
<20
<20 76
<20
<20 59
<20
<20 77
<20
<20 60
<20
<20 78
<20
<20 61
<20
<20 79
<20
<20 62
<20
<20 80
<20
<20 T-12
Figure 1: Torrey Pines (Main) Site North Land Areas 11/13102 N
WV(A S
Building 27 Service Yard Land Area Bldg. 21127 Land Hot Cell Site
I LZ=El I
.09 ý E49
..Z.99
.37.M 3
s m
--J ---- )
ý--j
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-.--)
-- -1
-_ --)
-_-J
-_-.I
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-- I pue-I Lz EF)PIS OLMS PJeA GOINGS LZ 5uipl!ng :Z ainbij
Figure 3: Building 27 Service Yard Ii I I IiI I
I Ii I
I
'I Ii I:
I I!
Ii I
I Ii I!
I I!
j:
II
'I Ii I: I
-10 I
met 10 meer II
Figure 4: Building 27 Service Yard Fixed Measurements and Wipes Locations and Results IAence r --..-.-.-..-..-....
<2Oct 105613Q<20a 1165 10 <2Oa 102413
<2Oct 0
(D 05613 (D <2,0 1100 3 OD<20a 10881 0
<20a 96113
'C <20a 110213 (0
<20ca 116313 0
<20a 1105130 I II "1<20 926130<20a 9813
( Il
<20ct 10613 (13) <I2 105613
<20a 11640 15 ko 105813 16
<20a 94213
<20a 11431 5S
<20a 1114 G
<20a 1034130
- o 92**_
__~hl*
o6 o
i<20az 109013 a
<20a 116813 a~
<20a 99313P <2c ii I
I.I
'109613 25j 2z1913
<2Oca 97513 a2
<20a 88513
<20, 1055(130 <20c,1109130 <20at 96130 II i
"982513 3 <20c a 1071
<20O 1
03613 Gas20a 1036
<20a1
<960 71 0 <20a t
99713 S
<20a 117413 0 <20a 966
<20a 9913 0 <2Oc9
<200t 94313
<20(t 9072
<20ac 914010 <20ca 1182130<20ca G
97413(2 <20ac 101413 (4) r20a 986134
<20a 94213 O
<20ac 96213(P <20ac1 99913 S
<20(1 986130 f o
kocc 111113 0
<20ct 96410 1
<20 10143 G
<20 a
.10351..8<20 10501 (D.
.20.
119813
<20.
916 I
<201 976138<20c 879130 <20ae 9051 1<20ot 97713 a
<20cc 994013j()
<20ac 97213G <20a
<20ar 103813 O~
~a 116813 0 a 96213 (D07<20cc 96313(0
<20(1 108513(
<20a 966134
<20a 1072130 ' <20cc 1195013i)
<20ac 10411302
<20cc 113613 4<20ac 102213
- 75)
.l2Oc 108613(IP
<20ac 1017P13
- 9~130<20cc :1151308 -<20r, 111913P f 10 meters tes:
- HkX Denotes one minute alpha fixed measurement in cpm. Maximum alpha result was < 20 cpm, < MDA.
- W Denotes two minute beta fixed measurement in cp2m Maximum beta result was 1198 cp2m, < MDA O
Denotes wipe location Wipe results are provided in Table 6.
Survey Conducted by: R Stowell Dates: 09-05-02 & 09-09-02 Model *
--- Ludlum 2221 Ludlum 12
- S e r iai#.:!:
86302 91051
- !.Cai:D3esDate&:
11-12-02 02-22-03 j;*::.fob7&Iiý>
100 cm2 p 50 cm2 at
- y lbe # !-!: "
142547 094053
_-..,.,Effjciency..7.j 34.95%
21.77%
1220 +1-170 0O-20 cpm cp2m mIO: cm2
]V.
236 216
Figure 5: Building 27 Service Yard Alpha and Beta Surface Scans Locations and Results
~~~~~
'I
\\I 1900-2600 p 1800-2500 p 10-40 a 10-40 cc 10-40 a10-40 cc I
I "I
I L
Ii I.
III 2000-2700 p 2000-2600 p 10-40 a 10-40 a Ii.
II
--I.
II 1900-2800 p 2000-2700 p 10-40 a 10-40 1900-2800 p 2000-2600 p II 10-40oc 10 met.
er.s l
10 meters 10-40 a IN Notes:
j1.
100% of accessible surface area scanned for alpha and beta.
- 2.
- -## a Denotes alpha scan results in cpm Results range from 10-40 cpm.
3.
40f 13 Denotes beta scan results in cpm. Results range from 1800 - 2800 cpm.
I I,iI
°-ro Surveys Conducted by: R Stowell & J Sullivan Dates: 08-05-05 to 10-06-02 IS--
~)
- -:K-.::sMdeks Ludlum 2221 Ludlum 2221 Ser a#
154202 148426 Cal Du Date 11-13-02 1-20 04-01-03
- Probe~
434 cm2 13 434 cm 2 C Probe;#
149017 086236 2834%
..... cenc...
30 17%
21.09%
-- (a
.'i,-.-,-12400-2800 cpm 10-40 cpm
L L
10 meters Figure 6: Building 27 Service Yard Exposure Rate Fixed Measurements Locations and Results
.I*
ence
- 16 17 16 17 16 1 16 16 16 15 14*
II j16 17 18 18 17 1 17 17 18 17 16 II l
j
- 16 17 17 18 171 17 17 18 18 16 I!
i16 18 18 17 17 17 17 18 18 17
.I
- 16 17 18 18 1
18 18 18 18 19 718I 1
17 17 17 18 184 19 18 18 17 17:
III 17 17 17 18 181 18 18 18 19 17 I
171 17 18 18 1811 18 18 18 19 187 I
I 17 17 18 18 18' 17 18 19 19 17 17 18 18 18 191 19 19 18 19 17 Model Ludlum 3 16 17 18 18 191 18 18 19 19 17 Serial#
153311 I
ICal Due&Dated:
09-13-02 16 17 18 18 18 18 19 19 18 17 1 Prob6b 2"x2"Nal y
-Prbobe 155594
, 16 17 18 19 18 1 18 18 18 19 17 Bkgd-(asPhalt).
11-19 jR/hr I.
I 1116 18 17 18 18 18 18 18 18 17jI I:
I ______
116 17 17 17 18 i18 18 19 18 17 1;18 1116 16 16 16 18118 19 19 19 17 N
=
Notes S17 17 15 16 18 18 19 19 19 17
- 1.
All readings are in g*R/hr taken 1 17 17 16 16 17 17 18 19 18 18 1
1 meter above the surface.
S18 18 18 1
- 2.
Results range from 14 - 19 gR/
S17 18 16 16 18 18 18 1
8 17 J17 18 17 18 17 118 18 18 18 17:
II I
1
- 117 18 17 16 18 118 18 18 18 17 1117 16 16 15 17 118 18 18 18 171:
.1- -- -
-- - - -- - -- - -I Survey Conducted by: R Stowell Date: 09-04-02 at
/hr.
Figure 7: Building 27 Service Yard Exposure Rate Scans Locations and Results
---1------------------.----------------
Ii 15-21 15-20 I:
I.
i-.....................
I 16-21 17-21 Ii 1!
17-21 18-21 It It 14-21 18-21 14-21 14-20
- 1
?,fence soil I,
I.
i:
14-16 II 14-17 17
- Notes:
-Mode I Ludlum 3 serrat#
153311 09-13-02 a; Due Date-,
12-11-02 P-r--
be*-
2" x 2" Nal y 0be# *,
155594 Bkgd-(so!l) 11-17 p.R/hr Bkg l(asphalt) 11-19 p.R/hr 100% of accessible surface scanned.
All readings are ranges in p.R/hr taken at
<1" from the surface.
Results range from 14-17 pR/hr (soil) and 14-21 pR/hr (asphalt).
I7 10 meters Survey Conducted by: R Stowell Dates, 08-30-02 to 10-06-02
- 2.
3.
Figure 8: Building 27 Service Yard Soil Sample Locations and Exposure Rate Measurements eI r
4 I-
- -_° m. m ° 1o.,
I5 I!
I 5
I47 IQ 2525A
-~.~--
-a~p~Jt46 II ii
- --sp~ -J
_srl II jT II I
i_.
53 Gp4444 54 I:
I
'a (D9
,!4 I) O C) f I I
0-41
,f 10 meters Samples Collected by: R. Stowell Dates, 09-12-02 to 09-17-02 Sample # -Contact @1-meter Sample # -Contact -
1 mete 19 18
. 28..
19 19 2
18 18
ý-29:
17 17 3/3A 18 17 30s 19 16 4
19 18
---:.:31-:
18 18 5 -
18 15 32 x.
18 17
"*6 19 18 3333A' 19 18
-7 17 16 34 17 17 8 :
19 17 35/35A.
18 17 919A 18 17 36-::
18 18 10 19 18
.37--
1 1
.- 1 19 18
-:---38::
18 17
-ý-ý-"12 19 18
.39:::::. 18 1
18 13 17 16
- 40§:
18 17
14 16 16
- -41-:-:
15 15
-1 5 17 16
- '42. --::
15 14 16.--
16 16
-::43 -:-'
15 15 17ý-
17 17
- 44:
14 15 S8'_-_-
19 19 45-:-
16 16 9
19 18
__4 16 16 2
-0 18 18
- 47:::
15 15
-T21I 19 18 48:.':
14 15
-22 i19 18 49--;-
15 15 23 18 17 50.-:-:,
14 13
"--+/-
4* :-"
18 17
- 51t>*
16 15
---25/25A.j 19 18 52 ;:::
18 17 26 19 19 53a-:ýý-
17 16
-27/27A 19 18 54 *-:-
18 16
- -- M od e Ludlum 3
- i*S Orja1 :
153311
-sCat-Due.Date-*
12-11-02
- Pr blbe*:q 2"X2" Nal Probe er;#:
155594
,_ýBkgd {:soil) ::
11-17 ;i.Rhr Bk5gdk(asphalt) 11-19 giR/hr Denotes sample number and approximate location.
@N~
Denotes dual sample collected 0-6" and 6-12".
N Denotes samples 51 through 54 original locations.
Samples 51 through 54 were collected from soil that covered part of the asphalt along the east fence. This soil was later moved off the asphalt along the west fence.
5 Exposure rate measurements were taken at each location, on contact and at 1 meter.
- 6.
Sample results are provided in Table 5.
ý-.Ep-qs u-r 6 R ate 6Me ais~ureme nts; in 'o RI hr.
Vý kw i
W I
ll
Figure 9: Building 27 Service Yard Remediations
',Jence I1
,s o I
9300 dpm/100 cm 2 particle Ii Post Remediation Results I
2300 cpm beta scan with 434 cr 2 probe.
1025 cp2m fixed beta measurement with I
100 cm2 probe Soil sample #40 collected at this location I:i I
~-----------------------
T-
'I IL*'*~~12 cp~m f1(1r;ixe 1be *L[measurement with]
10 J ocm2 probe SSoil sample #30 collected at this location.
IiI I!
li
(
9800 dpm/100 cm2 particle I:
Post Remediation Results 2400 cpm beta scan with 434 cm2 probe 1169 cp2m fixed beta measurement with II 100 cm2 probe I:
Soil sample #20 collected at this location I!
I!I
- 1 10 meters Note" During initial beta scans three particles were found embedded in the asphalt at the locations shown. These were chipped up from the surface and disposed of as radioactive waste.
Following remediation a two minute fixed beta measurement was taken and the surface scanned using a 434 cm2 beta detector.
In addition, soil samples were collected under the asphalt at these locations. The results of these samples are provided in Table 5.
Survey Conducted by: R Stowell Date: 08-23-02 1200 dpm/100 cm2 particle Post Remediation Results 2300 cpm beta scan with 434 cm2 probe.
M~de i
Ludlum 2221 Ludlum 2221 Senai#
- 154202 86302 a
e-Date 11-13-02 01-23-03 Pnbe.
i 434 cm 2 1 100 cm2 p Prob*--#
149017 142547 Eff iti'En t 28.34%
34 95%
ýf 3 acg*ud P
q 1220 +/- 170O
- r.
2 4 0 0 -2 8 0 0 c p m acp2m 236 dNA dpm/00 cm I I I
I i
General Atomics' Final Radiological Survey Report For Building 27 Service Yard Land Area Appendix A Final Survey Plan A-1
Page 1 of 3 June 24, 2002 0
5 Prepared By: W. T. LaBonte Approved By:
~
4 V L. Q. Gonzales U Final Radiological Survey Plan for Building 27 Service Yard Land Area This Final Survey Plan is for Building 27 Service Yard, (a.k.a. Counting Yard), Land area. This parcel of land, which is approximately 9,700 ft2 ( -900 Mi2), is a fenced in area immediately adjacent to, but isolated by a fence from, Building 27, which lies to the east. See Figure-I for Building 27 Service Yard Land Area location and Figure-2 for the Land Area boundaries, dimensions, and grid layout for this land area.
This Final Radiological Survey Plan covers only open land areas, the majority of which are paved with asphalt.
History and Classification Initially, this land was used as a temporary storage area for radioactive materials and supplies used to support the Building 27 (Radio-chemistry laboratory) and Building 27-1 (EA-1 Bunker) activities.
During decommissioning activities at GA, this land area was used for the preparation of low level radioactive material for shipment and ultimate disposal off-site, a temporary storage area for low level radioactive waste awaiting shipment, and, a portion of this area was used to perform gamma spectroscopy analysis on shipping containers filled with low level radioactive waste.
This area was also used as the "lay-down" area for sections of the EA-1 Bunker Building during it's demolition. The building sections were painted and moved to the waste yard for packaging in preparations for shipment to a low level waste burial site.
This land area is classified as a Suspect Affected Area for survey purposes due to the extensive use of this area for the handling and temporary storage of radioactive material.
Survey Objectives and Responsibility The purpose of performing a final survey is to demonstrate that the radiological conditions within the Building 27 Service Yard Land Area satisfy the NRC and State of CA guidelines for release to unrestricted use. The objectives include (1) to show that the average surface contamination levels for each survey unit are within the authorized value, (2) to show that the maximum residual activity ("hot spot" area) do not exceed three times the average value in an area up to 100 cm2 and (3) that a W \\Budding 27 Service %Npd A-2
Page 2 of 3 reasonable effort has been made to clean removable contamination and fixed contamination and (4) that the exposure rates in occupiable locations are less than 10 itR/hr above background measured at I meter above the surface. Samples will be counted in the Health Physics laboratory (onsite). Surveys will be taken only by qualified Health Physics Technicians having a minimum of 3 years Health Physics Technician experience. The survey and final report documenting the survey will be performed by GA's Health Physics group.
Release Criteria (per GA Site Decommissioning Plan)
Concrete/Asphalt Surface Release Criteria The NRC release criteria for Sr-90, which is conservatively selected for beta measurements due to the exposure of this area to the EA-1 Bunker building pieces, is:
1,000 dpm /100 cm 2, averaged over a I m 2 area 3,000 dpm /100 cm 2, total, maximum in a 100 cm2 area 200 dpm/1 00 cm2, removable activity The NRC release criteria for Alpha activity (Sr-90 is not an alpha emitter) is:
5,000 dpm /100 cm2, averaged over a Im2 area 15,000 dpm /100 cm2, total, maximum in a 100 cm 2 area 1,000 dpmr/100 cm 2, removable activity Exposure Rate Measurements The guideline value for exposure rates measured at 1 m above the' surface, is 10 pR/hi" above background.
Alert Levels Alpha Alert Values If the following "alert levels" are exceeded, notify HP Management so an evaluation can be performed and to evaluate if decontamination is required.
> 100 cpm alpha using the large area (434 cm2) probe (check area with a hand-held alpha meter).
> 60 cpm using a 50 cm2 hand-held alpha probe (- 600 dpmr/l00 cm2)
Beta Monitoring
>250 cpm above the appropriate background using the 434 cm2 probe.
>100 cpm above the appropriate background using the 100 cm 2 probe.
>40 cpm above background using a portable GM detector. (Note: this meter should ONLY be used in areas the 434cm2 or 100 cm 2probes will not fit).
W \\Building 27 Service.wpd A-3
Page 3 of 3 Exnosure Rate Measurements
> 25 f.1Rihr at surface
> 20 htR/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.
Final Radiological Surveys Planned for the Building 27 Service Yard Land Area Type of Survey/Activity Suspect Affected Area Gridding Required?
Yes Asphalt or Concrete Surfaces (1) 100%
(Scan w/ 434 cm2 alpha probe).
Asphalt or Concrete Surfaces (1) 100%
(Scan w/ 434 cm2 beta probe)
Minimum number of I measurement per 4 m', or, Measurements (2) (3) 1 measurement every -2 m Alternate between (1) a wipe, (2) an alpha fixed measurement and (3) a beta fixed measurement on all asphalt or concrete surfaces.
Asphalt/core samples Sample the asphalt and take a 0-6" soil sample at the 4 areas identified on Figure-3. Take 6 Core samples at the locations identified on Figure-3.
Core samples should consist of: the asphalt core plug, 0-6" and 6"-12"of soil beneath the asphalt. Additional core samples and/or asphalt remoial may be required based on direct scan survey results as determined by HP Management.
ltR/hr Readings (Scan Survey) 100% scan on all surfaces, detector held -1" from surface l.tR/hr Readings (Fixed 1 every 2m Measurements @ Im from surface)
(1)
(2)
(3)
Clean surfaces, debris or dirt removed For the fixed measurements*
For a measurements; use either the hand held alpha counter (minimum of-6 second count).
Document all readings in cpm.
For P3 measurements; take a 2 minute count using the 100 cm2 gas flow proportional detector (beta) with the Model 2221 ratemeter.
Document all readings and mark on a drawing the locations the readings were taken.
For wipes, analyze each 100 cm 2 wipe for a and P3 activity.
A "measurement" is either (1) a "fixed" radiation measurement representing total activity or (2) a wipe (removable activity).
A-4 W \\Building 27 Service -Apd
Figure 1: Torrey Pines (Main) Site North Land Areas 11113102 Building 27 Service Yard Land Area Bldg. 21127Lad
- Bunkert Land ATFF Bldg. 21
&RLactor B-22 Admin-Area Hot Cell Site Mk III
F -
I---
I-( "---
Figure 2: Building 27 Service Yard w
S +
N S...................................................................-...............................
155'4" "SOORBROK.I 61'3 "
150' 66' 2" Bldg. 27 Land w
CD
.5 B=27 I
(
F
F
V V
V
F
F F
17 U-
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I I
General Atomics' Final Radiological Survey Report For Building 27 Service Yard Land Area L
Appendix B Confirmatory Survey L
Appendix B Building 27 Service Yard Land Area GA Confirmatory Survey Description Following the completion of the Building 27 Service Yard Land Area Final Survey, a Confirmatory Survey was performed by Health Physics Technicians in accordance with an approved Survey Plan (see attachment-i). The Building 27 Service Yard Land Area is illustrated in Figure 1.
The purpose of this survey was to confirm that the Final Survey was effective in identifying the radiological conditions of the area.
This confirmatory survey consisted of:
- 1.
Three (3) surface (0-6") soil samples of the unpaved surface on the western boundary.
See Figure 2 for locations, and Table 1 for sample analysis results. The results contained in Table 1 are summarized below:
Cs-137 Co-60 U-238 U-235 Th-228 Th-232 in pCi/g in pCi/g in pCi/g inpCi/l in pCi/g in pCi/g High 0.47 +/- 0.10
<0.16 2.06 +/- 1.98 0.15 +/- 0.13 1.51 +/- 0.21 1.87 +/- 0.37 Low
<0.13
<0.16
<1.58 0.12 +/- 0 08 1.22 +/- 0.18 1.12 +/- 0.25 Average 0.24
<0 16 1.74 0.14 1.34 1.49 (N=3)
Notes:
- 1.
Less than (<) values indicate that the radionuclide was not detected so the average minimum detectable activity (MDA) was used:
U-238 = 1.58 pCi/g (63 keV peak)
U-235 = 0.14 pCi/g (186 keV peak)
Cs-137= 0.13 pCilg (662 keV peak)
Co-60 = 0.16 pCi/g (1173 keV peak)
Th-228 = 0.21 pCi/g (238 keV peak)
Th-232 = 0.43 pCi/g (911 keV peak)
- 2.
The sum of fractions for any sample was far less than 1.0
- 3.
All results were far less than the approved release criteria.
- 4.
The average is based on all positive results and the MDA value when activity was not detected.
U-238, U-235, Th-228, Th232 were not discernible from natural background. "
Cs-137 was detected in all three (3) samples. The highest concentration was 0.47 +/- 0.10 pCi/g which is far below the approved release criteria of 15 pCi/g.
B-2
- 2.
Exposure rate scans were performed on 100% of the surface with a 2" x 2" NaI(TI) detector held within 1" of the surface. The range for the measurements at 1" from the surface was 14 to 21 p.R/hr. See Figure 3 for locations and results.
- 3.
Fixed exposure rate measurements 1 m apart in each of 10 grids (1 Om x 10 m grids) at 1 m from the surface. The range was 15 to 19 VR/hr. See Figure 4 for locations and results.
- 4.
10% of the asphalt surface was scanned with a 434 cm 2 gas flow proportional detector for a and P3 activity. The 0X measurements ranged from 7 to 48 cpm, the natural background was 7 to 25 cpm. Fixed measurements were taken in the highest scan areas. See below for fixed measurement summary and Figure 3 for locations and results. The P3 activity ranged from 2080 to 3325 cpm, the background measurement, taken in a non-impacted area, was 2400 to 2900 cpm. Fixed measurements were taken in the areas with the highest scan results. See the fixed measurement summary below, Figure 5 for a scan survey locations and results and Figure 6 for [3 scan survey locations and results.
- 5.
Ten (10) fixed cc measurements were taken at the locations of the highest measurements obtained during the surface scans. The highest measurement was <20 cpm. The natural background was 0-20 cpm. See Figure 2 for locations and results.
- 6.
Eleven (11) fixed [3 measurements were taken at the locations of the highest measurements obtained during the surface scans. The highest measurement was 1215 cp2m, the natural background was 1371 +/- 55 cp2m. See Figure 2 for locations and results.
Conclusion All of the Confirmatory Survey results indicated that activity levels on the Building 27 Service Yard Land Area are below the approved release criteria, which agrees with the Final Survey results.
B-3
F-F-
r-ir
[--
[--
I---
7 Table 1: Building 27 Service Yard Land Area Confirmatory Soil Sample Results Radionuclide Concentrations (pCilg)
Background Not Subtracted, 30 min. count U-238 U-235 Cs-137 Co-60 Th-228 Th-232 Sample ID
,(Th'-234: 63Kev, 93 (i44Kev,186 Key (662 Key)
(1170 Key)
(Pb-214: 238 Key)
(Ac-228: 911 Key)
Key used when 63 used when 144 not not present) present) pCi/g pCifg pCi/g pCi/g pCi/g pCi/g 1
CY-!
206 +/- 198 0 12+/- 008 ND ND 151 +/-021 1 87+/-037 2
CY-2 ND 0 141007 0 13 +/--005 ND 1,29-016 1 12+/-025 3
CY-3 ND 0 15k0 13 047:-0 10 ND 122 +/-0 18 1 47 +/-036 Notes.
1.
ND means not detected.
- 2.
Average Minimum Detectable Activities (MDAs):
U-238 = 1.58 pCi/g (63 keV peak)
U-235 = 0.14 pCi/g (186 keV peak)
Cs-137= 0.13 pCi/g (662 keV peak)
Co-60 = 0 16 pCi/g (1170 keV peaks)
Th-228 = 0.21 pCi/g (238 keV peak)
Th-232 = 0.43 pCi/g (911 keV peak)
B-4 I-
Figure 1: Torrey Pines (Main) Site North Land Areas 11/13/02 N
S Building 27 Service Yard Land Area Bldg. 21/27 Land Hot Cell Site Mk III
F
r
r;-
v
(...
[--I
(-- -
( "-- -
Figure 2: Building 27 Service Yard Comfirmatory Fixed Measurement and Soil Sample Locations s20
_<20 Ei#7i= Fixed P reading In cn2m
<20
= Fixed a reading In corn T
Soil Sample Location Surface Is Asphalt All areas with higher count rates were Identifide and checked with handheld Instruments and the 100cmt gas proportional probe. Bkg for 0 on asphalt -1371 +/- 55 cp2m MDA for P on asphalt
343dpml100cml, Bkg for P on concrete = 1042_+/-.90 cp2m, MDA for 0 on concrete = 313 dpmll00cmn Bkg for a on asphalt = 0-20 cpm MDA for a on asphalt = 297 dpml100cm2 B-27 B-6 W
A E
<20
<20
<20 520
_20
_520 CU (I-I....
(--".
('--.
j
=1
F--
II--
C V -.
v" F----
1---
U--
fT U
VT w
oniepa 5f 27 Counting Yard Confirratory
",Idsttrtin106 Model 3 Model 3 N/A N/A SerlAl Ntflife'r, 153311 151348 N/A N/A C1bi'tfiiftDS 12/11/02 01/15/03 N/A N/A hFf0x5e6a 8
N/A N/A N/A N/A 1Y N/A NIA iP.l*b: Nt~ii.b 155594 163169 NIA N/A to2"m xS~m2 2"x2 2 2"x2" NIA N/A Comments Bickgrou~nd is 19 -21 uR/hr for Aspohjlt At -I" Ant results are reported in IrR/hr.
Signature.
Cowan and J. Sulhivan Date-IM0102,JM22 Figure 3: Building 27 Service Yard Comfirmatory Exposure Rate Scan B-7 w
A S4 4f*N E
(.... -
I7.- -
I r--
f
[_r..
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( ---
f.-
.r f'--
F--.-
I--
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(v-F..
(--
U-Figure 4: Building 27 Service Yard Comfirmatory Fixed Exposure Rate measurements w
E 2Countin Yard Confirinator
' ~
Model 3 N/A N/A N/A 1531 N/A N/A N/A N/A N/A N/A N/A 1554 N/A N/A NI 2" x2" N/A N/A N/A
'omns Background Is 11-19 pR/hr for Asphalt at
-lMeter and 14.16 at -iMeter concrete Signature. S. Cowan and I. Sullivan Date.
iisa
Figure 5: Building 27 Service Yard Comfirmatory Alpha Scan t~
Surface Is Asphalt. All areas with higher count rates were Identifde and checked with handheld Instruments. See fixed reading results.
B-9 r
r F.
r ------
[....
W A
E Signature LEUMM
, "*'"J'*.",*
- otla,*:;~%,.
I r -
1 -."
F...
f --
F
[ - *--
rl- - -
F - -
f -
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,'-
4-...
- r.
r-r-
v r
(
Figure 6: Building 27 Service Yard Comfirmatory Beta Scan Signature
&CMM Date.
INMI4*
Surface Is Asphalt. All areas with higher count rates were Identilfide and checked with count rate Instruments. See fixed reading results.
B-10 W
A E
Anseeuiir 2221 N/A N/A N/A S6AM 9 4459 N/A N/A N/A a britrAflu Q203 N/A N/A
'IA ZEM e
31 08%
N/A N/A N/A N/A N/A N/A P'row anbneY 086215 N/A N/A NI bPfohSzbntw 434 I
N/A N/A N/A Comns0ikruds20-90p All results are reported In cpm.
J OI-unt-I]
-r I.. 1
-rRI.-
General Atomics' Final Radiological Survey Report For Building 27 Service Yard Land Area to Appendix B Confirmatory Survey Plan B-11
Page 1 of 3 October 11, 2002 Prepared By: W. T. LaBonte Approved By:
Q (L/0 L. Q. Gonzales Confirmatory Radiological Survey Plan for Building 27 Service Yard Land Area This Final Survey Plan is for Building 27 Service Yard, (a.k.a. Counting Yard), Land area. This parcel of land, which is approximately 9,700 ft2 ( -900 in2), is a fenced in area immediately adjacent to, but isolated by a fence from, Building 27, which lies to the east. See Figure-i for Building 27 Service Yard Land Area location and Figure-2 for the Land Area boundaries, dimensions, and grid layout for this land area.
This Confirmatory Radiological Survey Plan covers only open land areas, the majority of which are paved with asphalt.
History and Classification Initially, this land was used as a temporary storage area for radioactive materials and supplies used to support the Building 27 (Radio-chemistry laboratory) and Building 27-1 (EA-i Bunker) activities.
During decommissioning activities at GA, this land area was used for the preparation of low level radioactive material for shipment and ultimate disposal off-site, a temporary storage area for low level radioactive waste awaiting shipment, and, a portion of this area was used to perform gamma spectroscopy analysis on shipping containers filled with low level radioactive waste.
This area was also used as the "lay-down" area for sections of the EA-I Bunker Building during it's demolition. The building sections were painted and moved to the waste yard for packaging in preparations for shipment to a low level waste burial site.
This land area is classified as a Suspect Affected Area for survey purposes due to the extensive use of this area for the handling and temporary storage of radioactive material.
During the performance of the Final Radiological Survey, three (3) "hot particles" were discovered, removed and disposed of as low level radioactive waste.
Survey Objectives and Responsibility The purpose of performing a confirmatory survey is to verify the radiological conditions identified during the Final Radiological Survey.
W \\Building 27 Service confirm wpd B-12
Page 2 of 3 Release Criteria (per GA Site Decommissioning Plan)
Concrete/Asphalt Surface Release Criteria The NRC release criteria for Sr-90, which is conservatively selected for beta measurements due to the exposure of this area to the EA-I Bunker building pieces, is:
1,000 dpm /100 cm 2, averaged over a Im 2 area 3,000 dpm /100 cm2, total, maximum in a 100 cm 2 area 200 dpm/100 cm2, removable activity The NRC release criteria for Alpha activity (Sr-90 is not an alpha emitter) is:
5,000 dpm /100 cm2, averaged over a 1 m2 area 15,000 dpm /100 cm 2, total, maximum in a 100 cm 2 area 1,000 dpm/100 cm', removable activity Exposure Rate Measurements The guideline value for exposure rates measured at I m above the surface, is 10 piR/hr above background.
Alert Levels Alpha Alert Values If the following "alert levels" are exceeded, notify HP Management so an evaluation can be performed and to evaluate if decontamination is required.
> 100 cpm alpha using the large area (434 cm 2) probe (check area with a hand-held alpha meter).
> 60 cpm using a 50 cm2 hand-held alpha probe (- 600 dpm/100 cm 2)
Beta Monitorin'
>250 cpm above the appropriate background using the 434 cm 2 probe.
>100 cpm above the appropriate background using the 100 cm2 probe.
>40 cpm above background using a portable GM detector. (Note: this meter should ONLY be used in areas the 434cm2 or 100 cm2 probes will not fit).
Exposure Rate Measurements
> 25 [IR/hr at surface
> 20 IFR/hr at I m Minimum Confirmator2, Survey Requirements
- 1.
Perform an exposure rate scan on 100% of the asphalt surfaces using a 2" x 2" NaI(T1) detector held within 1" of the surface and at 1 meter from the surface.
- 2.
Perform a beta scan, using a 434 cm 2 gas flow proportional detector, on 10% of the total asphalt surface area.
B-13 W \\Building 27 Ser ice confirm wpd
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- 3.
Perform an alpha scan, using a 434 cm2 gas flow proportional detector, on 10% of the total asphalt surface area.
- 4.
Take fixed alpha and beta measurements at the ten (10) highest measurement locations observed while performing the alpha and beta scans.
- 5.
Take three (3) equally spaced surface soil samples (0-6") along the western fence line.
Documentation Every survey conducted must be documented on a daily basis on a drawing showing the approximate locations surveyed. Include the results (including units), the technicians signature, date, instrument(s) used (including model and serial number of both the ratemeter and the detector), calibration due date,
% efficiency, background readings (if applicable) and any other applicable information.
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