ML091000374
| ML091000374 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 02/26/2009 |
| From: | Tallman D A Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| Shared Package | |
| ML090830613 | List:
|
| References | |
| DPG 09-097, F8000073 | |
| Download: ML091000374 (16) | |
Text
Rancho Seco Final Status Survey Summary Report February 26, 2009 Western IA (Northern omission)Survey Unit F8000073 Prepared By: Dan A. Tallman Z__ -Date: February 26, 2009 FSS Engineer Reviewed By: ,D a Date: Lead FSS Engineer Approved By: _ ?/ Date: Dismantlement Superintendent, Radiological FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit: F8000073, Western IA (Northern omission)Survey Unit
Description:
Operating History: This area is located on the west side of the Industrial Area to the north of the spray ponds. Specifically, -250 square meters adjacent, to the NW comer of the current IA security fence omitted from survey coverage in F80,00071 and F8000141.
Operating records and the HSA document the potential for a release of radioactivity associated with this survey area. Radioactive material may have been temporarily stored in this area Site Characterization:
Soil and sediment samples were collected and analyzed for the presence of plant-derived radionuclides. Cs-137 was the only
'1etected nuclide of plantorigin with a mean activity level of 0.062 pCi/g and a maximum value of 0.299 pCi/g.(Site background levels of Cs-137 have been determined to bei approximately 0.312 pCi/g.) As described in section 2 of the LTP, the area was eva~luated using DSIP-0020 and was designated as Class 3.Survey Unit Design Information:The Survey Unit Design Parameters are presented in Table 1 below. The survey unit and measurement locations are depicted on the ma~s in Attachment
- 1. Direct measurement locations were randomly determined and 30 m were scanned for approximately 12%coverage.
Soil samples were collected at each direct measurement location and analyzed by HPGe detector.
The instrumentation used for the survey along with the MDC values are listed in Tables 2-1 and 2-2 in Attachment 2.Page 2 of 7 FSS Summary Report F8000073 Table 1. Survey Unit Design Parameters Survey Design Parameter Value CommentSurvey Area:
F800 Western IA(Northern omission)Survey Unit:
0073 Open Land Area Class: 3 LTP Table 5-4 SU Area (m2): 255 Evaluator:
D.A.Tallman DCGL Cs137 surrogate (pCi/g): 51.2 Area Factor: N/A Class 3 Design DCGLemc (pCi/g): N/A Class 3 LBGR (pCi/g): 25.6 Default = 50% DCGL Design Sigma (pci/g): 0.034 DTBD-06-001, Table 5-4C Type I Error: 0.05 Type II Error: 0.05 Nuclide: Cs137 Sample Area (m2): N/A Class 3Total Area Scanned (m2): 30 Scan Coverage (%): 11.8% Class 3 ZIa : 1.645 ZIP : 1.645 Sign P: 0.99865 Calculated Relative Shift: 752.9 Relative Shift Used: 3 Uses 3.0 if Rel Shift >3 N-Value: 11 Design N-Value + 20%: 14 NUREG-1575 Table 5-5 Grid Spacing L: N/A Class 3 Page 3 of 7FSS Summary Report F8000073 Survey Results: A total of 14 direct measurements were made in F8000073. The results including mean, median, standard deviation and range are shown in Table 2. All of the direct measurements were less than the DCGL. None of the scan measurements indicated areas of elevated activity with an observed scan range of 6363-7239 cpm with the 44-10 Nal detector instrument.
Soil samples were counted to the MDC shown in Table 2-1 of Attachment 2.Table 2. Direct Measurement Resý,ults (all activity values in pCi/g)Measurement ID Cs137 MDA Cs137 Activity Uncertainty Mean:4 6.19E-02 Median: , 6.06E-02 Standard Deviation:
9.58E-03 Range: 4.93E-02 to 8.46E-02 F8000073S0001ISS 5.90E-02 < 5.90E,-02 F8000073S0002SS 6.07E-02 < 6.07E-02 F8000073S0003SS 5.47E-02 < 5.47EL02 F8000073S0004SS 6.04E-02 < 6.04EL02 F8000073S0005SS 7.19E-02 < 7.19EL02 F8000073S0006SS 6.35E-02 < 6.3 5E--02 F8000073S0007SS 6.59E-02 < 6.59E-02 F8000073S0008SS 5.25E-02 < 5.25E-02 F8000073S0009SS 4.99E-02 < 4.99E-02 F8000073SOO1OSS 4.93E-02 < 4.93E-02 F8000073SO01ISS 6.58E-02 < 6.58E-02 F8000073S0012SS 8.46E-02 < 8.46E-02 F8000073S0013SS 5.75E-02 < 5.75E-02 F8000073S0014SS 7.03E-02 < 7.03E-02 Page 4 of 7FSS Summary Report F8000073 Attachment I Maps February 26, 2009 Survey Unit F8000073
-e cj~KEY PLAN-~~ zi 11)u\-y k-) 1 ,4 -) L L, i-~QOOG7L~]
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4 Ar-A~-A. V-.1-- -+/-V-HI4-Th-R'-IV.I-TAA+/-44-T~T,_ _+ ~ + ~H+/--- 3/1 ~ T T44 -1~-4A 44 -1;i iA48--4 ;HH i444 t-I+/-H-I11!!11 i I..-+l-;!!!;1H4-I+4A-H-' F1!~1 1. / ... ., ....1 .......:--4--. ...-N, ~/I: /S...... ....T 4.........T.4, 00 1A 'A 1 t3 / +3 +/- w : -- 34_ _ _ _ _ _ _6-i--4-!-f-'-i--1--
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I IIH.I(4H H1111 I 444 H---+ _ _ _ _ _ _ __+
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14-iA+~rr/ 4 5 SM UD RANDOM SAMPLE LOCATIONS4-'-l-l1-~ -r-I 4-'I-IV.--V.rH--4 ACRAM NI4O MUNICIPAL 43LTIjlT'f DISTRICT 8000073-M2
__ fiFIE:8800007 SHT I OF 2 L)A TALLM~ANA Tr-4 6 7 a 2 L) 12 13 14 ý 1 "i IS '? a 10 CD 0 j cm in-KEY PLAN 00 i , /I i ,, /S /S /, /i(///" I//7/I/////,//WESTERN IA (North omission)SOIL SAMPLE LOCATIONS 8000073-M2 SARAM Ec 14 MUNIC:49.L (J)(01)KEY PLAN 171ýACR,'MEWTO MUNICIPAL UJTIlI-T DISTRICT WESTERN IA (North omission)SCAN SURVEY LOCATIONS 8000073-M3-E: 8000007 SHT i OF 1 DA TALLD Attachment 2 Instrumentation February 26, 2009 Survey Unit F8000073 Table 2-1. Survey Unit Instrumentation Detector Detector Serial Instrument Model No.MDC.No.2350-1 44-10 256101 5-6 pCi/g HPGe N/A 05069128 Soil -0.085 pCi/g Cs-137 Ludlum 2350-1 w/ Nal detector (44-1O/SPA-3) MDA for distributed soil activity 6 pCi/g.Table 2-2. Investigation Criteria andi DCGL Instrument Parameter Value 2350/44-10 Investigation Criteria -Scan 9750 cpm ISOCS Investigation Criteria -Direct Soil -25.6 pCi/g Cs-137(,ur.)
All DCGLw 51.2 Cs-137'12.6 Co-60 All DCGLEMc N/A -Class III'2350-1/44-10 Investigation Level calculated IAW DSIP-0510 (encl. 8.6)Page 2 of 2 Att. 2 Instrumentation F8000073 Attachment 3 Investigation February 26, 2009 Survey Unit F8000073 (none required)
Attachment 4 Data Assessment February 26, 2009 Survey Unit F8000073 F8000073 Quantile Plot CsI 37 DCGL = 51.2 pCi/g a 0 cj~a cd~U)00 0.090 -0.080 0.070 -0.060 -0.06~-0.050> 0.040 0.030 0.020 -0.010 -0.000 -0 20 40 60 80 100 Percentile I
- Activity -Median ---75th Percentile ----50th Percentile I
(D 0 F8000073 Scatter Plot Cs137 DCGL = 51.2 pClIg 0 cn cn rD C'D O0 0 0 Lu U on_>I .OOE-01 9.OOE-02$.0OE-02 7.00E-02 6,QOE-O2 5.OOE-02 4.OOE-02 3OOE-02 2.00E-02 1.OOE-02 O.0OE+10-0 0 0 0 0...........- - -a -" 00 0 0 0 0 0-m , -,a -m -m -t a , a~ a m -, -at a, a a, --B a, -, m , ,........i.. ... ...I .1 .! ....!
- I * .. i .-l T L L ! T. -I II : : -L ....!" D.091 0.061 10031 Measurement Locations 1 o Activity "- Average " "+3StDev " -"-3StDev"I F8000073 Frequency Plot 00 00 Cs1 37 DCGL = 51.2 pCi/g 7 6 a1)LL 0.-0 0 5 4 3 2 1 0 4J V CIO Bins -Upper End Value (pCi/g)