ML17065A036

Rancho Seco Nuclear Generating Station - Final Status Survey Report, October 14, 2016, Iosb DAW Bay, Survey Unit F8300013

ML17065A036
Person / Time
Site:	Rancho Seco
Issue date:	11/10/2016
From:	Sacramento Municipal Utility District (SMUD)
To:	Office of Nuclear Material Safety and Safeguards
Shared Package
ML17065A032	List: ML17065A034 ML17065A035 ML17065A036 ML17065A037 ML17065A038 ML17065A040 ML17065A041 ML17065A046 ML17065A047 ML17065A048 ML17065A049 ML17065A051 ML17065A052 ML17065A053 ML17065A054 ML17065A055 ML17065A056 ML17065A057 ML17065A058 ML17065A059 ML17065A060 ML17065A061 ML17065A063 ML17065A064 ML17065A065 ML17065A066 ML17065A068 ML17065A069 ML17065A070 ML17065A071 ML17065A072
References
DPG 17-038, F8300013
Download: ML17065A036 (16)

Text

j i. ------. --Rancho S.eco Final Status Survey Summary Report October 14,, 2016 IOSB DAW Bay Survey Unit F8300013 Approved By: fl'>#:e<-Date: '.c /.o L=t.(, Manager, Rancho Seco Assets FINAL STATUS SURVEY F8300013 Survey Unit: F8300013, Interim Qnsite Storage Building (IOSB) Dry Active Waste (DAW) bay Survey Unit

Description:

Operating History: fhe DAW Bay was <tesigned to as a holding or storage bay for dry activated waste (DAW) packaged in shipping containers. There was a known of contamination in the northwest corner of the bay near the drainage trench. This area. was fully characterized Quring the scoping surveys and did not resµlt in static measurements exceeding the DCGL. Site Characterization: Static were made of the walls, floor, and ceiling of the DAW Bay to confirm the absence or presence of plant-derived radionuclides. measurements showe.d a mean gross activity level of 3,042 dpm/ 100 cm2 and a maxim.um value of 5,778 dpm/100 cm2* The statistic:S of the DAW results combines all lower walls, upper walls, floor, and ceiling data. Based, on the levels of gross activity reported, the area was determined to be a Class 3 area. Survey Unit Design Information: The Survey Unit Design Parameters are presented in Table 1. The survey unit and measurement locations are depicted on the. maps in Attachment 1. Static measurement locations were randomly determined and approximately 12% of the area scanned. The instrumentation used! for the survey along with the MDC values are listed in Table 2 ... 1 Attachment 2. 1 FSSDAWBAY F8300013 FINAL STATUS SURVEY F8300013 Table 1, Survey Unit Design Parameters Evaluation Input Values Comments Survey Package: F830 IOSB Survey Unit: 001 DAW Bay Class 3 SU Area (m2) 348 Evaluator: JR DCGLw: 43,000 Gross Activity DCGL Area Factor N/A Class 3 Design DCGLemc (dpm/1 OOcm2): N/A Class 3 DCGLemc: NIA Class 3 LBGR: 21,500 Default = 50% DCGL Sigma: 1,055 Scopinq Survey Data Type I error: 0.05 Type 11 error: 0.05 Predominant Nuclide Cs-137 Sample Area (m2) N/A Total Instrument Efficiency: 0.129 Total Area Scanned (m2): 40.3 Scan Coverage (%) 12% Class 3 Choosing 'N/A' sets material Material Type: N/A backqround to "O" Calculated Values Comments Z1-a: 1.645 Z1-p: 1.645 Sign p: 0.99865 Calculated Relative Shift: 20.3 Relative Shift Used: 3.0 Uses 3.0 if Relative Shift >3 N-Value: 11 N-Value+20%: 14 2 FSS DAW BAY F8300013 FINAL STATUS SURVEY F8300013 Survey Results: A total of 15 direct measurements were made in F8300013. The results of the static measurements are shown in Table 2. All of the static measurements were less than the DCGL. None of the scan measurements indicated areas of elevated activity. Swipe data did not indicate elevated activity levels above the MDA. Table 2, Static Measurement Results Number Sample# Beta Beta (cpm) (dpm/100 cm2) 1 F8300013C0001 274 2,023 2 F8300013C0002 261 2,093 3 F8300013C0003 266 2,388 4 F8300013C0004 327 1,946 5 F8300013C0005 254 2,364 6 F8300013C0006 251 2,535 7 F8300013C0007 194 2,287 8 F8300013C0008 273 2,062 9 F8300013C0009 180 1,395 10 F8300013C0010 308 1,969 11 F8300013C0011 257 1,504 12 F8300013C0012 305 2, 124 13 F8300013C0013 295 1,992 14 F8300013C0014 203 2,116 15 F8300013C0015 270 1,574 Table 3 contains the statistical summary of the static measurement data for the DAW Bay. 3 Table 3, Beta Summary Statistics Beta Static DAW (dpm/100 cm2) Mean Median Standard Deviation Minimum Maximum Count FSS DAW BAY 2,025 2,062 325 1,395 2,535 15 F8300013 FINAL STATUS SURVEY F8300013 Survey Unit Data Assessment: The survey design required 14 static measurements for the Sign Test. A total of 15 static measurements were collected. The critical value and the results of the Sign Test are presented in Table 4. The sample mean and median values were less than the DCGL. The sample standard deviation was greater than the design standard deviation but both values of sigma resulted in a relative shift greater than three (3 ), no additional samples were required. Table 4, Data Assessment Results Static Data Values Comments Number of Samples: 15 Median: 2,062 Mean: 2,025 Static Data Standard Deviation: 325 Maximum: 2,535 Sian Test Results Comments Adjusted N Value: 14 S+ Value: 15 Critical Value: 10 Criteria Satisfaction Comments Sufficient samples collected: Pass Maximum value <DCGLw: Pass Median value <DCGLw: Pass Mean value <DCGLw: Pass Maximum value <DCGLemc: NIA Sign test results: Pass Final Status Comments The survey unit passes all conditions: Pass Survey Unit Investigations and Results: No investigations were required for either direct or scan measurements and no investigation results are reported. ALARA Statement: As stated in Chapter 4 of the L TP, as long as the residual activity within the survey unit is less than the DCGL, the ALARA criterion has been met. Changes in Initial Survey Unit Assumptions: The survey unit was designed as a Class 3 survey and the sample results are consistent with that classification. The variability of the survey results was greater than the characterization data used for survey design. No potential areas of elevated activity were detected. 4 FSSDAWBAY F8300013 FINAL STATUS SURVEY F8300013 as both were in excess of maximum amount and required adjustment to 3.0 No potential areas of elevated activity were detected.

Conclusion:

The FSS of this survey unit was properly designed as a Class 3 survey based on the results of the scoping survey. The required number of direct measurements was made and the scan coverage met the requirement of Table 5-6 of the LTP. All of the static measurements were less than the DCGL. No investigations were required. The static measurement data support rejection of the null hypothesis, providing high confidence that the survey unit satisfied the release criteria and ithat the data quality objectives were met. It is concluded that survey unit F8300013 meets the release criteria of 1OCFR20.l402. 5 FSS DAW BAY F8300013 Maps October 14, 2016 Survey Unit F8300013 SMUD Wl TIDEWATER INC UNil tt-S I SCUJlllU I nlOlua *nt,U.H DAW BAY SMUD Approve<! Dy. Dale: 101l(J01<* Approwl dote: Rev No.: l Page 1 F830001 -1 0, 23 10 2,023 dp 100 cm2 ..... rF8300013-9 32, 8 22 1 395 dpm/100 cm rF8300013-7, 13 19, 22 f 2 287 dpm/100 cm2 F8300013-11, 9 50 18 1 504 dpm/100 cm2 F8300013-13 27 30 0 1 992 dpm/100 cm2 rF8300013-3 4, 11, 0 .I 2 388 dpm/100 cm2 F8300013-14. 65 47, 22 2 116 dpm/100 cm2 (F8300013-8. 51 50 16 2 062 dpm/100 cm2 F8300013-2 72 39, 2 093 dpm/100 cm2 F8300013-4,41 28 0 1 ,946 dpm/100 cm2 F8300013-10. 69 24 0 1 969 dpm/100 cm2 rF8300013-12 46 13. 0 / 2 124 dpm/100 cm2 F8300013-5,52 0,20 2 364 dpm/100 cm2 Att. 1 Maps rF8300013-15 75 2 1 574 dpm/100 cm2 F8300013-6 75 1 r 10. 2 535 dpm/100 cm2 F8300013 Instrumentation October 14, 2016 Survey Unit F8300013 Measurement Type Beta Static Measurement Swipe Measurements Table 2-1. Survey Unit Instrumentation Instrument Type Ludlum Model 2350-l Ludlum Model 44-1 16 B Detector Ludlum Model 2929 Ludlum Model 44-10-1 / Minimum Detectable Activity" Beta -510dpm/100cm2 Alpha -25 dpm/100 cm2 Beta -80 dpm/100 cm2 Detector Efficiencies 12.9% 36.9% 42.8% Calibration Due Dateb 317899/331973 2110/17 166716/170380 11/3/16

• Minimum detectable activities for the count rate instrumentation were calculated in accordance with NUREG-1507, "Minimum Detectable Concentrations with Typical Radiation Survey Instruments for Various Contaminants and Field Conditions" (U.S. NRC, 1997). b Detectors are required to be calibrated once every 12 months. Calibration due date indicates the date by which the detector must be calibrated again. cm2 =square centimeters cpm =counts per minute dpm =disintegrations per minute Page 1 Att. 2 Instrumentation F8300013 Static Measurement MDA Variables Beta Survey Type 331973 Detector Number 182 Background count rate (cpm) Count Time (min) 0.129 Efficiency Area of Detector 100 (cm2) Constants 60 sec/min 2.54 cm/in Assumptions Background count time and sample count time are equivalent Calculate Static MDA Static MDA =3 + 4.65(Br

• t)0*5/t

• E

• A/100 (NUREG 1507) Where: Static MDA Page 2 Br t E A Background Countrate Count Time (min) Efficiency Area of detector (cm2) 510 dpm/100 cm2 Att. 2 Instrumentation F8300013 Att. 3 Investigation Attachment 3 Investigation September 21, 2016 Survey Unit F8300013 (none required) F8300013 Data Assessment October 14, 2016 Survey Unit F8300013 Histogram for Beta Static Activity DAW Bay (dpm/100 cm2) ....... 1J NlllbeldV<&te1: "....,,, 1,l!!il!\ """""" z.::1 so ,._.... -0581 ........ -0.00 G'JMoon 2JJ201 G'JM .... 2Jl6> 01..e.n:a .. 0MOl'e8m 1"'5 1628 1191 1953 211& 2279 Page I Att. 4 Data Assessment F8300013 Q..Q Plot for Beta Static Activity DAW (dpm/100 cm2) 2400 1!0) 1600 1400 *1.5 05 00 0.5 Thoorotical Quantiles (Standard Normal) Page 2 Att. 4 Data Assessment 1.0 1.5 F8300013 Mean*2025 Sd*325.3 Slopo*329.5 ,...,,.,....2025 *ees1Ftlne I IOSB Final Status Survey I LCl LC2 LC3 LC4-LC6 LCS j3 CPM (3 dpm Date/Time of Count Sample Comments 1 F830 001 3 c 00001 SM DAW Bay Areil 65 35 09/09/16 13:25 2 F830 001 3 c 00002 SM DAW Bay Area 62 28 '09/09/16 13:26 3 F830 001 3 c 00003 SM DAW Bay Area 66 38 09/09/16 13:28 4 F830 001 3 c 00004 SM DAW Bay Are(] 50 0 09/09/16 13:29 5 F830 001 3 c 00005 SM DAW Bay Area 49 -2 09/09/16 13:30 6 F830 001 3 c 00006 SM DAW Bay Area 52 5 09/09/16 13:32 7 F830 001 3 c 00007 SM DAW Bay Area 39 -25 09/09/16 13:33 8 F830 001 3 c 000.08 SM DAW Bay Area 43 -16 09/09/16 13:34 9 F830 001 3 c 00009 SM DAW Bay Area 52 5 09/09/16 13:36 10 F830 001 3 c 00010 SM DA w Bay. Area 55 12 09/09/16 13:37 11 F830 001 3 c 00011 SM DAW Bay Area 40 -23 09/09/16 13:38 l2 F830 001 3 c 00012 SM DAW Bay Area 65 35 09/09/16 13:40 13 F830 001 3 c 00013 SM DAW Bay Arca 51 3 09/09/16 13:41 14 F830 001 3 c 00014 SM DAW Bay Area 53 7 09/09/16 i3:4.2 15 F830 001 3 c 00015 SM DAW Bay Area 61 26 09/09/16 13:43 Comments By signature below, the required source check and background checks were satisfactorily f)erformed prior to use of the instrument identified below. ! . Ludlum 2929 Benchtop Instrument bl:1: elficir:*ntv bkp, tount 2929 S/N: 166716 rate tirne MDA 3 1 24.8 44-10-1 S/N: 1 70380 a 0.369 c:pm 1i1in dp1i1 pe*r are;.i Tech A Sign/ Date (l, /!AVLI-' I ?-7-lt J3 49.9 1 79.7 Tech B Sign/ Date I I* Cal Due Date: 11/3/2016 0-428 NIA cpm min dpm pi::i;;ire;.i Page 3 Att. 4 Data Assessment F8300013