ML17065A052

Rancho Seco Nuclear Generating Station - Final Status Survey Summary Report, December 1, 2016, Iosb Storage Cell C-3, Survey Unit F8300243

ML17065A052
Person / Time
Site:	Rancho Seco
Issue date:	12/15/2016
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
Download: ML17065A052 (16)

Text

Rancho Seco Final Status Survey Summary Report December 1, 2016 IOSB Storage Cell C-3 Survey Unit F8300243 Prepared ____ Date: 12 . t 2 * 't.P FSS Engineer Approved By: "1:1.<.!!Ac= Date: 1z(,:7/i(, Manager: ancho Seco FINAL. ST A TUS SURVEY F8300243 Survey Unit: F8300243, Interim Onsite Storage Building (IOSB) Storage Cell C-3 Survey Unit

Description:

Operating History: Designed primarily to store packaged radioactive waste containers safely, protected from the elements, and maintain radiological dose as low as reasonably achievable (ALARA), each storage cell possibly stored media of many types, including filters, resins, contaminated chemicals, DAW, activated reactor components, contaminated plant components and other contaminated items. Site Characterization: Static measurements were made of the interior surfaces of the storage cell, to confirm the absence or presence of plant-derived radionuclides. Static measurements showed a mean gross beta activity level of 2, 179 dprn/100 cm2 and a maximum value of 4,674 dprn/100 cm2* 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 below. The survey unit and measurement locations are depicted on the maps in Attachment 1. Static measurement locations were randomly determined and approximately 33% of the area scanned. The instrumentation used for the survey along with the MDC values are listed in Table 2-1 Attachment 2. FSS Storage Cell C-3 F8300243 FINAL STATUS SURVEY F8300243 Table 1, Survey Unit Design Parameters Survey Packaqe: F830 Storaqe Cell C-3 Survey Unit: 24 Class 03 SU Area (m2) 23 Evaluator: JR DCGLw: 43,000 Gross Activity DCGL Factor N/A Class 3 Design DCGLemc (dpm/100cm2): N/A Class 3 DCGLemc: N/A Class 3 LBGR: 21,500 Default = 50% DCGL Siqma: 365 Scoping Survey Data Type I error: 0.05 Type II error: 0.05 Predominant Nuclide Cs-137 Sample Area (m2) N/A Total Instrument Efficiency: 0.132 . --** -*--.. ---------. Total Area Scanned (m2): 7.51 Scan Coverage (%) .::i::t;_,;:33°/o;' Class 3 Choosing 'NIA' sets material Material Type: NIA background to "O" >-<*> >.,:_'1. *, *. .} Z1-a: .L645 Z1-a: .. 1.64.5 Siqn o: 0:99865 Calculated Relative Shift: 58.9

• Relative Shift Used:

• 3.b Uses 3.0 if Relative Shift >3 N-Value: 11 N-Value+20%: 14 2 FSS Storage Cell C-3 F8300243 FINAL STATUS SURVEY F8300243 Survey Results: A total of 15 direct measurements were made in F8300243. 111e 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 *" .. . .

• Ni.imber **. .** Beta (cpm) * *. J3eta (dpm) *,/. 1 F8300243X00001 262 1,985 2 F8300243X00002 275 2,083 3 F8300243X00003 283 2,144 4 F8300243X00004 302 2,288 5 F8300243X00005 262 1,985 6 F8300243X00006 288 2,182 7 F8300243X00007 265 2,008 8 F8300243X00008 256 1,939 9 F8300243X00009 267 2,023 10 F8300243X00010 245 1,856 11 F8300243X00011 282 2;136 12 F8300243X00012 245 1,856 13 F8300243X00013 254 1,924 14 F8300243X00014 275 2,083 15 F8300243X00015 289 2,189 Table 3 contains the statistical summary of the static measurement data for the Storage Cell C-3 3 Table 3, Beta Summary Statistics Beta Static Storage Cell C-3 Mean Median Standard Deviation Minimum Maximum Count FSS Storage Cell C-3 2,045 2,023 127 1,856 2,288 15 F8300243 FINAL STATUS SURVEY F8300243 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. Table 4, Data Assessment Results Number of Samples: 15 Median: , 2;023 Mean: ** 2,045 Static Data Standard Deviation: .* * **127. Maximum: 'i,288 Adjusted N Value: .14 S+ Value: * ** 15 Critical Value: * .

• 10 Sufficient samples collected: *

• Pass *-------** Maximum value <DCGLw: , :Pass* Median value <DCGLw: * ,Pass Mean value <DCGLw: Maximum value <DCGLemc: * . *NIA Siqn test results: *. Pass 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: . t'. As stated in Chapter 4 of the LTP, 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 less than the characterization data used for survey design. No potential areas of elevated activity were detected. 4 FSS Storage Cell C-3 F8300243 FINAL STATUS SURVEY F8300243 Conclusfon: 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 s:atisfied the release criteria and that the data quality objectives were met. It is concluded that survey unit F8300243 meets the release criteria of 1OCFR20.l402. 5 FSS Storage Cell C-3 f 8300243 Maps December 1, 2016 Survey UnBt F8300243 A-I -2 A-3 B*1 B-2 B*3 0*1 0-2 0-3 E-1 E-2 E-3 SMUD tract o.: SMUD by: Rotv No.: Page I F8300243X0006 I** 2 182 Clf)ni'100 cm* $ F830024 3X0010 p . I 856 o.Jpm/100 a F8.300243X0001 fi 1 <JJ:>m/100 c Reference Point Att. I Maps 000 I Z OC!3 jon '100 cm $ -2 288 dp 100 cm' $ F8300.'.'43XOOO:'. I -2 OS dpi 11 f'8300"'43X 14 r = 08..l dPm/100 tr $ Fe:>00243XOO :? I ' dpmt100 cri cm' F6300:43X0007 $ F8300.'43X001.3 I -1 :24 dPIT\1100 pn' r. = :? 00 dpm/100 cm F830024 3X0003 = :' 144 dpmll $ cm' F830024 001 " 1 -? 1 apm1100 cm' c:" **. .* F8300243 F .* ... Instrumentation October 11, 2016 Survey UnBt F8300243 -* -"!"" ---. ---------

Type Beta Stati(; Measurement Swipe Measurements Table 2-1. Survey Unit Instrumentation * * ** * * . Minimum ity:U. Deteetor I_.n. t_ T, .. Y* .p_ e . . . .. . . . * *

• Efficiencies Ludlum Model 2350-1 Ludlum Model 44-116 B Detectot Ludlum Model 2929 Ludlum Model 44* l 0-1 Beta -532 dpm/I 00 cm2 13.2% Beta -79 dpmi' I 00 cm2 42.8% Calibration . DU,e Dateb 317897 /33 I 972 2/10/17 166716/I 70380 l l/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 f 8300233 Static Mea'Surement MDA Variables Beta Survey Type PR331972 Detector Number 209 Background count ra\te (cpm) Count Time (min) 0.132 Efficiency 100 Area of Detector ( crri2) 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 (crri2) 532 dpm/1 OGl cm2 Att. 2 Instrumentation F8300233 Att. 3 Investigation Attachment 3 Investigation December 1, 2016 Survey Uniit F8300243 (none required) F8300243 Data Assessment December 2, 2016 Survey Unit F8300243 Histogram for Beta Static Activity (dpmf100 cm2) Cell C-3 I Humbe1ofVDlie1 M"""" 1.856.Cli M"""'" 2.287.BB SD 127.03 Sk"""" Q18 Kuto:h -0.67* ' {ti Mc_.,,,* 2.045"'51 0Medi11n 2.022.73! el Nom\oll 0Lett8ii:: 0Mae8m 11l57 1"1) 1943 1906 2073 2116 2159 = 2245 2289 Page 1 Att. 4 Data Assessment f 8300243 2160 2100 1900 1920 1860 Q..Q Plot for Beta Static Activity (dpm/100 cm2) C-3 /: / /. /. // TheoreUcal QuanUles (Standard Normal) Aclivty ti" 15 Slope* 131.5 lntoreep1*2045 Cocrelatim.R *O.SSS *1.5 *1.0 -0.5 0.0 Q5 1.0 1.5 J Page2 Att. 4 Data Assessment F8300243 Smear _Data_ Calculation_Sheet _lOl.31,6 IOSB Final Status Survey LCl . l.C2 .LO .l.C4 LC6 . LCS llCPM lldpm Date/Time of Count Sample Comments J F830 024 3 x 00001 SM Cell C-3 42 -18 10/12/16 1048 2 F830 024 3 x 00002 SM Cell C-3 37 -29 10/12/16 1018 3 F830 024 3 x 00003 SM C.3 46 .9 10/12/16 0958 4 F830 024 3 x 00004 SM Cell C.3 51 3 10/12/16 1042 5 F!:IJO 024 3 x 00005 SM Cell C-3 48 .4 10/12/16 1008 6 F830 024 3 x 00006 SM Cell C-3 49 -2 10/12/16 0950 7 . F830 024 3 x 00007 SM Ceil C-3 62 28 10/12/16 1039 8 F830 024 3 x 00008 SM Cell C.3 49 -2 10il2/16 1033 9 F830 024 3 x 00009 SM Cell C-3 43 -16 10/12/16 1007 10 F830 024 3 x 00010 SM Cell C-3 53 7 10/12/16 1045 J:I F830 024 3 x 00011 SM Cell C-3 51 3 10/12/16 1025 12 F830 024 3 x 00012 SM Cell C-3 35 -3'1 10/12/16 1004 13 F830 024 3 x 00013 SM Cell C-3 58 19 10/12/1.6 1030 111 F830 024 3 x 00014 SM Cell C-3 37 -29 10/12/16 1016 15 F830 024 3 x 00015 SM CcllC-3 42 -18 10il2/16 0957 Comments By signature below. the r('Quircd source check and background checks were satisractorily;performed prior 10 use ol lhe instrumcni identified below. Ludlum 2929 Benchtop Instrument bl:i: bl<r. (QU:ll 2929 S/N: 182597 r:nc MDI\ , 0.364 -.>.U C( l°t. l 11.> J -J 43-10-1 S/N: 188736 t:prn 111i11 dpm pc!r arc;i Tech A Sign/ Date <Z:fa,J/V/ H'.J1JI-; 12-2.-1"7 49.8 l 78.6 Cal Due Date: 5/13/7.017 .Tech Jl i'iJA cpm min --= Page 3 Att. 4 Data Assessment F8300243