ML17065A061

Rancho Seco Nuclear Generating Station - Final Status Survey Summary Report, January 25, 2017, Iosb Loading Dock, Survey Unit F8300071

ML17065A061
Person / Time
Site:	Rancho Seco
Issue date:	02/09/2017
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: ML17065A061 (15)

Text

Approved By: Rancho Seco Final Status Survey Summary Report January 25, 2017 ......... IOSB Loading Survey Unit F8300071 FSS Engineer Date: R:nhOSeco Assets FINAL STATUS SURVEY F8300071 Survey Unit: F8300071, Interim Onsite Storage Building (IOSB) Loading Dock Class 1 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: Based upon the scanning results of the Truck Bay an elevated area was identified on the floor around and including the loading dock. Certain spots in the area exceeded the DCGLw but not the DCGLEMC* This area required remediation. The Truck bay was divided into a small Class 1 Survey Unit, buffered by a Class 2 Survey Unit. The remainder of the Bay was designated as a Cla$S 3 Survey Unit. The Class 3 and Class 2 areas are the subject of separate reports. Survey Unit Design Information: In accordance with MARSSIM Section 4.6, special considerations may be necessary for survey units with structure surface areas less than I 0 m2 or land areas less than I 00 m2. In this case, the number of data points obtained from the stati$tical tests is unnecessarily large and not appropriate for smaller survey unit areas. The data generated from these smaller survey units should be obtained based on judgment, rather than on systematic or random design, and compared individually to the DCGLs. This survey unit meets this criterion as the size is less than ten square meters (7 .5 m2). 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 based upon professional judgment and approximately I 00% of the area scanned. The instrumentation used for the survey along with the MDC values are listed in Table 2-1 Attachment 2. FSS Loading Dock Class 1 F8300071 FINAL STATUS SURVEY F8300071 Table 1, Survey Unit Design Parameters Survey Packaqe: F830 Loadinq Dock Class 1 Survey Unit: 007 Class 1 SU Area (m2) 7.5 Evaluator: JR DCGLw: 43,000 Gross Activity DCGL Area Factor 3.4 DTBD-05-003 DesiQn DCGLemc (dpm/100cm2): 146,200 DCGLemc: 146,200 LBGR: 21,500 Default= 50% DCGL Sigma: 466 Truck Bay ScopinQ Type I error: 0:05 Type II error: 0.05 Predominant Nuclide Cs-137 Sample Area (m2) N/A Total Instrument Efficiency: 0.130 Total Area Scanned (m2): 7.5 Scan Coveraqe (%) '.:X:1o6o/d:: Class 1 Choosing 'N/A' sets material Material Type: NIA backQround to "O" ;*' ;.,* .. : ' . -* * ;, :* ,J < .:;\**.** :; .. *' >tJ ':,::cBmmeiit$:* .,.; ;:.

• Z1-a: 1:645. Z1-a: 1.645 SiQn p: 0.99865 Calculated Relative Shift: 46.1 , Relative Shift Used: 3.0 Uses 3.0 if Relative Shift >3 N-Value: N-Value+20%: Survey Results: Values selected based upon 15 Judqement Values selected based upon 15 Judqement A total of 15 direct measurements were made in f 8300071. 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. 2 FSS Loading Dock Class 1 F8300071 FINAL STATUS SURVEY F8300071 Table 2, Static Measurement Results " -.* -" .. . :*$ample# (yP!ll) .. (dpm), *. .. . , .. "* !;-'. 1 F8300071C00001 959 7,265 2 F8300071C00002 360 2,727 3 F8300071C00003 377 2,856 4 F8300071C00004 407 3,083 5 F8300071C00005 533 4,038 6 F8300071C00006 477 3,614 7 F8300071C00007 390 2,955 8 F8300071C00008 331 2,508 9 F8300071C00009 254 1,924 10 F8300071C00010 321 2,432 11 F 8300071MOOO11 280 2, 121 12 F 8300071 MOOO 12 634 4,803 13 F8300071 M00013 425 3,220 14 F8300071 M00014 532 4,030 15 F8300071 M00015 249 1,886 Table 3 contains the statistical summary of the static measurement data for the Loading Dock Class l. Table 3, Beta Summary Statistics Beta Static Loading Dock Class 1 Mean Median Standard Deviation Minimum Maximum Count Survey Unit Data Assessment: 3,297 2,955 1,376 1,886 7,265. 15 The survey design was based upon professional judgement and resulted in 15 static measurements. Following the guidance in MARSSIM Section 4.6, these values are compared directly to the DCGLw. The comparison and the results are presented in Table 4. The sample mean and median values were less than the DCGL. 3 FSS Loading Dock Class l F8300071 FINAL STATUS SURVEY F8300071 Table 4, Data Assessment Results .comment's* Number of Samples: 15 Median: 2,955, Mean: 3,297 Static Data Standard Oeviation: 1,376 Maximum: 7,265 ,., '., .. ,. ': -. c_riterla .** .. .,. '. -. Sufficient samples collected: Pass Maximum value <DCGLw: Pass Median value <DCGLw: Pass

• Mean value <DCGLw: Pass Maximum value <DCGLemc: N/A Si!:in test results: N/A .. ,. 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: *i 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 I 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. However, no individual measurement exceeded the DCGL. No potential areas of elevated activity were detected. Conclusion: The FSS of this survey unit was properly designed as a Class I 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 that the data quality objectives were met. It is concluded that survey unit F830007 l meets the release criteria of I OCFR20. l 402. 4 FSS Loading Dock Class 1 F8300071 Maps January 30, 2017 Survey Unit F8300071 Page J SMUD oottoc No.: A Location: -t.:mrhn "Drow'ng W\ F8300071 M00009 1,924 dpm/100 cm2 F8300071M00015 1.886 dpm/100 cm2 F8300071C00001 p = 7,265 dpm/100 cm2 F8300071 M00011 p = 2, 121 dpm/100 cm2 F8300071C00004 = 3.083 dpm/100 cm' l TIDEWATER IN I R/\OIOU';GtCALSCnvlCC:S SMUD Approved by. O.escriptlcn: LcJd .. 111: t)oc:'< l l Orown B . *. / lro:. Approval dole: Rev No.: -) 0 F8300071C00005 _/ p = 4,038 dpm/100 cm2 F8300071C00002 I\ = 2, 727 dprn/100 cm/ F8300071C00007 / 13 = 2,955 dpm/100 crn2 F8300071C00010 B = 2,432 dpm/100 crn2 Att. 1 Maps F8300071 M00006 0 = 3,614 dpm/100 cm2 F8300071 M00012 p = 4,803 dpm/100 cm2 F8300071 M00014 P = 4,030 dpm/100 cm2 F8300071C00008 B = 2,508 dpm/100 cm2 F8300071C00003 = 2,856 dpm/100 cm2 F8300071 Instrumentation January 30, 2017 Survey Unit F8300071 Table 2-1. Survey Unit Instrumentation * * * *

• JnstrumenfType Type Beta Static Ludlum Model Measurement 2350-1 Swipe Measurements Ludlum Model 44-1 16 B Detector Ludlum Model 2929 Ludlum Model 44-10-1 Mini mu rrt* Petecta hie ,* ' . ,. " . Beta -566 dpm/100 cm2 Beta -76 dpm/l 00 cm2 *Detedor . * *,* * 'F' 13.2% 43.4%

• nue 'i>ateb 317897/331972 2/10/17 182597 /188736 5/13/17

• 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 disintegrations per minute Page I Att. 2 Instrumentation F8300071 Static Measurement MDA Beta Survey Type PR331972 Detector Number 238 Background count rate {cpm) Count Time (min) 0.132 Efficiency 100 Area of Detector ( 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: Br Background Countrate t Count Time (min) E Efficiency A Area of detector (cm2) Static MDA 566 dpm/100 cm2 Page 2 Att. 2 Instrumentation F8300071 Att. 3 Investigation .Attachment 3 ,Investigation January 30, 2017 Survey Unit F8300071 (none required) F8300071 Data Assessment January 30, 2017 Survey Unit F8300071 Histogram for Beta Static Activity (dpm/100crn2) Loading Dock Class 1 6 -/"' / 5 5 I g 3 u.. 2 1 0

• 0 0 0 2152 2689 3227 3765 4303 4841 5379 5917 6455 Page I Att. 4 Data Assessment 1 ** 6992 F8300071 Numbe1 of Values Minimum Ma-.:irnum SD Skewne** Ku1tosis BMean BMedian B Nounal 0 isllibulion 0Less Bins OMoreBins I 15j 1.886.3*1 7.265.15 1.376.271 1.84 4.32 3.297.47 2.954.551

'7200 6400 5600 4800 :> :;::; u <( 4000 3200 2400 -1.5 Q-Q Plot for Beta Static Activity (dpm/100cm2) Loading Dock Class 1 * * -1.0 45 00 05 1.0 Theoretical Quantiles (Standard Normal) Page2 Att. 4 Data Assessment

• 1.5 F8300071 lh15 Mean= 3297 Sd = 1376 Slope* 1305 lnteicept = 3297 *cooelalion, R = 0.906 l!lil Best Fit Line F8300071 Smear _calc IOSB Final Status Survey II I LCl lC2 LC3 lC4 LC6 lC5 f3CPM f3dpm Date/TI me of Count Sample Comments --1 F830 007 1 c 00001 SM load Dock 39 -18 12/29/16 1303 2 F830 007 1 c 00002. SM Load Dock 44 -6 12/29/16 1304 3 F830 007 l c 00003 SM Load Dock 42 -11 12/29/16 1305 4 F830 007 1 c 00004 SM Load Dock 36 -25 12/29/16 1306 s F830 007 1 c 00005 SM Load Dock 45 -4 12/29/16 1307 6 F830 007 1 c 00006 SM load Dock 46 -2 12/29/16 1308 7 f830 007 1 c* 00007 SM* Load Dock 57 24 12/29/15 1311 8 f830 007 1 c (){J()()8 SM Load Dock 50 31 12/29/15 1312 9 f830 007 1 c 00009 SM Load Dock 36 -25 12/29/16 1313 10 f830 007 1 c 00010 SM Load Dode 43 -9 12/29/16 1314 11 F830 007. 1 c Oooll SM load Dock 53 15 12/29/15 1315 12 F830 007 1 c 00012 SM Load Dock 40 -15 12/29/15 1315 13 f830 007 1 c. 00013 SM Load.Dock 42 -11 12/29/16 1317 14 F830 007 1 .c SM. Load Dock 45 -4 12/29/16 1319 15 F830 007 1 *c 00015 SM Load Dode 41 -13 12/29/16 1320 Comments By signl!ture below, the required source check and background checks were satisfactorily performed prior to use of the instrument identified below. Ludlum 2929 Benchtop Instrument : . .l'<t: bkg 2929 S/N: 182597 rate t'.:nc: MDA 0.1 1 7.0 ex 0.364 43-10-1 S/N: 188736 cpm min p ...... df( .. , Tech A Sign/ Date ":*"' . 12/29/20Hi 0 46.7 1 76.2 Cal Due Date: 5/13/2017 0.434 Tech B Sign/ Date cpm min dp'11 ::i:of'i1 Page 3 Att. 4 Data Assessment F8300071