ML091000374

Rancho Seco Final Status Survey Report for February 26, 2009, Western IA (Northern Omission), Survey Unit F8000073

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: ML090830313 ML090830314 ML090830316 ML090830318 ML090830319 ML090830320 ML090830321 ML090830322 ML090830323 ML090830324 ML090830541 ML090830542 ML090830543 ML090830544 ML090830545 ML090830546 ML090830547 ML090830548 ML090830573 ML090850549 ML090850550 ML090850551 ML090850552 ML090850553 ML090850554 ML090850555 ML090850556 ML090850557 ML090850558 ML090850559 ML090850560 ML090850561 ML090850562 ML090890534 ML090890535 ML090890536 ML090890537 ML090890539 ML090890584 ML090890585 ML090890586 ML090890587 ML090890588 ML090890727 ML090900729 ML090900730 ML090900731 ML090900732 ML090900733 ML090900770 ... further results
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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Lc2 I H l nt's 2f (J'Q e d a r e 0 1 88991 ' N 00 SMUD SACRAIMENTO MUNI I-FILITY DISTRICT OIPAL WESTERN IA (North omission)GENERAL AREA 8000073-Ml 4-.. .. ......

0~ -43 H-1 x4- -4: --+A -~ -43 ~u T.t.j-"Pl7 i441 I -. -11+4Ii~i4~l~4I I 414 1-Al -V.1-144-* -r I4.4 fl-ý141IH4 I H 44 ll Ii 4 4+I.4411-14i-F-I-I 1441 A hl A1~K:'-WEA ,,,,I.2.. *~.i-,-I 4-T I+ *1t ilt t I I I I I I ; i I I I ; I i I I ;t ....y .. .-4-++/-1.(43 T ,, T4-- 441441 4IT- --4 44 M4 I ifH 4TI4H-+i 41 1V HI -,lA-lfI 4,+/- i4-AI-i A -14,- 1 .4-f fi -- 1 10 If 4i I t AI i 4 .4- 1144 141 V.1 J- 4 i 4--l. .1444 t ii i-i-l 4114f1A4H-4-1 ,-H I T fl+ il --1 1 -4 44 Ii- I 4- il111f 4I- H44 1-1-!;! T414.... /1 !1/ 1i- i H 144.H l.~ 4 IAl1;1 1 1i 'I I, 4114 F.1 Iri l I1 A~4+/-I-- 4I--II-Ii+~i -Ai-A---.

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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---+ _ _ _ _ _ _ __+

hA 1141 I,-i --44 I-4-44 /A A.KI ~4~4 l 4 l 4#14-~il+144 /I~,44~4--~4.

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)