ML17065A065
| ML17065A065 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 01/30/2017 |
| From: | Sacramento Municipal Utility District (SMUD) |
| To: | Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML17065A032 | List:
|
| References | |
| DPG 17-038 | |
| Download: ML17065A065 (16) | |
Text
{{#Wiki_filter:Approved By: Rancho Seco Final Status Survey Summary Report January 30, 2017 IOSB Hot Cell Class 2 Survey Unit F8300062 FSS Engineer ~~Date:~-th , Mana;JRJlChOSeco Assets
FINAL STATUS SURVEY F8300062 Survey Unit: F8300062, Interim Onsite Storage Building (IOSB) Hot Cell Class 2 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), the hot cell possibly stored media of many types, including filters, resins, contaminated chemicals, DAW, activated reactor components, contaminated plant components and other contaminated items. The Class 2 survey area encompasses the the walls above six feet up to and including the ledge where the lid rests. Site Characterization: Static measurements were made on the floor and wall surfaces, to confirm the absence or presence of plant-derived radionuclides. Static measurements showed a mean gross beta activity level of 2,880 dpm/100 cm 2 and a maximum value of 5,112 dpm/100 cm2* Previous surveys and floor scanning indicated significant contamination in excess of the DCGLw. This area was identified and characterized separately as a hot spot. The average static measurement in the hot spot was 390, l 04 dpm/100 cm2 and a maximum value of 2,285,918 dpm/100 cm2. Based upon the hot spot the Hot Cell was classified as a MARSSIM Class 1 survey unit. A Class 2 survey area was designated for the walls above six feet to the ledge where the lid rests. 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 100 m2. In this case, the number of data points obtained from the statistical 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 Jess than ten square meter (7.6 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 determined by professional judgment in accordance with MARSSIM guidance and approximately 100% of the area scanned. The instrumentation used for the survey along with the MDC values are listed in Table 2-1Attachment2. FSS Hot Cell F8300061
FINAL STATUS SURVEY F8300062 Table 1, Survey Unit Design Parameters
- Eva1uatfon *111i>1.1t:.v~ia0s.. *;,.
.:con1'inents Survey Package: F830 Hot Cell Class 2 Survey Unit: 06 Class 02 SU Area (m2) 08 Evaluator: JR DCGLw: 43,000 Gross Activity DCGL Area Factor NA Class 2 Design DCGLemc ( dpm/1 OOcm2): NA Class 2 LBGR: 21,500 Default = 50% DCGL Sigma: 740 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: 0.129 Total Area Scanned (m2): 7.6 Scan Coverage (%)
- ... 106.%. Class 2 Choosing 'N/A' sets material Material Type:
N/A backqround to "O"
- > ' * *,c:ii1~*t1'iate:a:.va'1u~$ * ' ; ':'.;*~:~*~:~*:*'I:.... : )*. 1.:.; :\\ *<'c'olllfue~rih,,;
Z1-a: 1.645 Z1-a: 1.645 Siqn p: 0.99865 Calculated Relative Shift: 29.0 Relative Shift Used: 3.0 Uses 3.0 if Relative Shift >3 Values selected based upon N-Value: 15 Judciement Values selected based upon N-Value+20%: 15 Judqement Survey Results: A total of 15 direct measurements were made in F8300062 following the guidance from MARSSIM section 4.6. 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 Hot Cell Class 2 f 8300062
FINAL STATUS SURVEY F8300062 Table 2, Static Measurement Results . 1 Number Sa1t1ple,# B.et~ (~pm) .Beta (dpin) 1 F8300062X00001 314 2,379 2 F8300062X00002 299 2,265 3 F8300062X00003 392 2,970 4 F8300062X00004 272 2,061 5 F8300062X00005 378 2,864 6 F8300062X00006 303 2,295 7 F8300062X00007 324 2,455 8 F8300062X00008 311 2,356 9 F8300062X00009 313 2 371 10 F8300062X00010 310 2 348 11 F8300062X00011 245 1 856 12 F8300062X00012 255 1 932 13 F8300062X00013 279 2 114 14 F8300062X00014 306 2 318 15 F8300062X00015 300 2 273 Table 3 contains the statistical summary of the static measurement data for the Hot Cell Class 2. Table 3, Beta Summary Statistics Beta Static Hot Cell Class 2 Mean 2,324 Median 2,318 Standard Deviation 296 Minimum 1,856 Maximum 2,970 Count 15 Survey Unit Data Assessment: The survey design was based upon professional judgement and resulted in 15 static measurements. Following the guidance in MARSSJM 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 Hot Cell Class 2 f 8300062
FINAL STATUS SURVEY F8300062 Table 4, Data Assessment Results
- -,.. **I Number of Samples:
- 15
- Median:
2,318 Mean:
- 2,324 Static Data Standard Deviation:
296 Maximum: 2,970 Sign T~s(Resi:Ht$.,* "::; *.... Adjusted N Value: 14 S+ Value: 15 Critical Value: . 10 Sufficient samples collected: Pass Maximum value <DCGLw: Pa$s Median value <DCGLw: Pass Mean value <DCGLw: Pass Maximum value <DCGLemc: N/A Si!::m 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: 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 2 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 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 2 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. 4 FSS Hot Cell Class 2 f 8300062
FINAL STATUS SURVEY F8300062 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 F8300062 meets the release criteria of I OCFR20.1402. 5 FSS Hot Cell Class 2 f 8300062 Maps January 30, 2017 Survey Unit F8300062
N F8300061X0009 F8300061X0005 f3 = 2,371 dpm/100 cm 2 f3 = 2,864 dpm/100 cm2 F8300061X0013
- F8300061X0007 f3 = 2, 114 dpm/100 cm2
= 2 455 dpm/100 cm2 ~~~~~~~~~~_!'._~~~_:_::_:_~~~~~~~~~~~~~-;--~r-~~ F8300061X0006 f3 = 2,295 dpm/100 cm2 F8300061X0004 f3 = 2,061 dpm/100 cm2 F8300061X0008 f3 = 2,356 dpm/100 cm2 F8300061X0001 f3 = 2,379 dpm/100 cm2 Top Edge of Hot Cell
- .Bottom *pclge ofhp,t Cell { ~1 ')...
'.. 1::* \\'
- -{
- Hot ce1f:Floor ("Tf:
- Reference point (x=O, y=O, z=1)
F8300061X0002 SMUD' TIDEWATER INC RADIOLOGICAL SERVICES f3 = 2,265 dpm/100 cm2 F8300061X0012 SMUD f3 = 1,932 dpm/100 cm 2 Location: Rancho Seco Task: Final Status Surve Approved by. Drawing No.: NA
== Description:== Drown B. Rev No.: Page 1 Att. 1 Maps F8300061X0015 f3 = 2,273 dpm/100 cm2 F8300061X0003
- f) = 2,970 dpm/100 cm2 F8300061X0010 f3 = 2,348 dpm/100 cm2
~.. F8300061X0014 f3 = 2,318 dpm/100 cm2 Hot Ct?ll prain (approx.). F8300061X0011 .0 f3 = 1,856 dpm/100 cm2 F8300062 Instrumentation January 30, 2017 Surve,Y Unit F83000062
Measureri1ent .,.. T.i'be.* Beta Static Measurement Swipe Measurements Table 2-1. Survey Unit *Instrumentation Ludlum Model 2350-1 Ludlum Model 44-1 16 B Detector Ludlum Model 2929 Ludlum Model 44-10-1 Minimu.m Detectable AC'tivify~ *
- .._,.,/*,,'
Beta - 499 dpm/l 00 cm2 Beta - 77 dpm/J 00 cm2 Detector* EfflCiericies 13.2% 43.4% Calibr.atibit'
- o~~ riii'te~
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 dpm =disintegrations per minute Pagel Att. 2 Instrumentation F830006l
Static Measurement MDA Beta Survey Type PR331972 Detector Number 183 Background count rate (cpm) Count Time (min) 0.132 Efficiency 100 Area of Detector (cm 2) 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 499 dpm/100 cm2 Page 2 Att. 2 Instrumentation F8300061
Att. 3 Investigation Investigation January 30, 2017 Survey Unit F8300062 (none required) F8300061 Data Assessment January 30, 2017 Survey Unit F8300062
/ 11"3 2116 Page 1 Histogram for Beta Static Activity (dpm/100 cm2) Hot Cell Class 2 m1 2450 Att. 4 Data Assessment F8300062 Ar.livq Nurnb.folV~ MIWrun M-11um so S*- Ki.Mto*i (!!Mean i:lM<don 1!3N~Oiruiu:ion 076 1.07 2.3237* 2.318.18
Q-Q Plot for Beta Static Activity (dprn/100 cm2) Hot Cell Class 2 2000 2200 2000
- 1.5
- 1.0
-0.5 no 0.5 Thoorotical Quantflos (Standard Normal) Page 2 Art. 4 Data Assessment 1.0 1.5 F8300062 Aclivq N *15 Me.v1*2324 Sd*295.8 Sk(le *293.7 11*crttol*232.t Couelalicn.A *0348
Smear _Data_ Calculation_Sheet _l0l316 IOSB Final Status Survey LO l.C2 1.(3 LC4 I.CG I.CS flCPM fl dpm Date/Time of Count Sample Comments 1 F830 006 2 c 00001 SM Hot U:ll lluflcr 42 -14 11/04/16 1323 2 f.830 006 2 c 00002 SM Hot Cell Bufler so 5 11/04/lG .t 324 3 F830 006 2 c 00003 SM Hot CPll Buffer 58 23 11/04/lG 132~ 4 FtnO 006 2 c 00004 SM Hal Cell Buller so s 11/04/16 1326 s Fl.{30 006 2 c 00005 SM Hot Cell Buffer
- 41.
-16 ll/04ll6 1328 6 FBJO 006 2 c 00006 SM HotC:dlOuf'fel' 57 2l I l/04/16 1329 7 F830 005 2 c 00007 SM Hot Cell Buffor 45 -7 1.1/0~/15 1330 8 F830 006 2 c 00008 SM Hot C~ll Buffer 49 2 11/04/16
- J.331 9
F830 006 2 c 00009 SM Hot Cell Buflc1* 46 -5 ll/04/16 1333 10 F830 006 2 c 00010 SM Hot Cell Buffer 49 2 11/04/16 l.334 11 F830 006 2 c 00011 SM Mal Cell Buffer 37 -25 .ll/04/lG 1335 12 1'830 00& 2 c OOOlZ SM Mot Cell Oufler 45 .7 ll/04/16 1336 13 F1:130 006 2 c 00013 SM MOl Cell OltfiOI' 54 14 11/04/16 1337 ~-- 111 F830 006 2 c 00014 SM 1*101 Cl'll Buffc" '.;2 9 11/04/16 1339 15 F830 OOG 2 c 00015 SM Ho1 Cell Buffer 45 .7 11/04/16 L3110 Comments r;v \\i&n;:tt.:ri: l>l'low, till* 11:qtii1 *:d ~ur<:i~ cfli..'(I; ;incl b<t<:l.:r.round Lh~a:., w1*10.* ~.oni:.f;1c1orilv perlarmi:d p:ior to v~ ol the 1n:-.tr\\1fl\\(flt *dl'ntii11~ b!.*tow. Ludlum 2929 Bcnchtop Instrument b~;r,
- .*fi1.:.;incy okr.
r.ovnt 2929 S/N: 182597 1Jt1;- tun(' MIJll /1 /""\\ 0.364 llDIV/01 j/ );;( J Cl. 113-lD*l 5/N: 188736 cpm r11i11 .-Jpm1lN;&rc*;1 Tech A Sien/ D;:i te f U (JI_,, y, (7 -L.-IC... 48 I 77.2 Cal Due Dilte: S/13/20l 7 [1 0.4.~11 Tech B Sign/ Date '-"' Nlr~ qm~
- nin dpm 1w1..i1c~
Page3 Att. 4 Data Assessment f 8300062}}