ML17065A054

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Final Status Survey Summary Report, December 13, 2016, Iosb Storage Cell E-3, Survey Unit F8300303
ML17065A054
Person / Time
Site: Rancho Seco
Issue date: 12/29/2016
From:
Sacramento Municipal Utility District (SMUD)
To:
Office of Nuclear Material Safety and Safeguards
Shared Package
ML17065A032 List:
References
DPG 17-038
Download: ML17065A054 (17)
v • d • e


Text

Rancho Seco Final Status Survey Summary Report December 13, 2016 IOSB Storage Cell E-3 Survey Unit F8300303 FSS Engineer Approved By: A?if>~ Date: 1z/M/,""

Manage::::S::o Assets

FINAL STATUS SURVEY F8300303 Survey Unit:

F8300303, Interim Onsite Storage Building (IOSB) Storage Cell E-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 activity level of 2,030 dprrill 00 cm2 and a maximum value of 2,483 dprn/100 cm2

  • Based on the levels of gross activity reported, the area was determined to be a Class 3 area.

Survey Unit Design lrlforinalion:

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 27% of the area scanned. The instrumentation used for the survey along with the MDC values are listed in Table 2-1 .

FSS Storage Cell E-2 . F8300293

FINAL STATUS SURVEY F8300303 Table 1, Survey Unit Design Parameters

, Eyal~aUQr1*1.Jput Yalu.es

      • * * .CPmh:ients. '*'

Survey PackaQe: F830 StoraQe Cell E-3 Survey Unit: 30 Class 03 SU Area (m 2) 28 Evaluator: JR DCGLw: 43,000 Gross Activity DCGL Area Factor NIA Class 3 Desiqn DCGLemc (dpml100cm 2 ): NIA Class 3 DCGLemc: NIA Class 3 LBGR: 21,500 Default= 50% DCGL SiQma: 182 ScopinQ Survey Data Type I error: . 0.05 Type II error: 0.05 Predominant Nuclide Cs-137 Sample Area (m2) NIA Total Instrument Efficiency: 0. 132 Total Area Scanned (m2): 7.51

  • Scan Coveraqe (%) l**::**J?iz%:~ Class 3 Choosing 'NIA' sets material Material Type: NIA backqround to "O"

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  • ,c'P'mmenf~ ': .. ;t)"i'"'t::

Z1-a: ' 1.645' Z1-o: 1.645 Siqn p: 0.99865 Calculated Relative Shift: '118.1 Relative Shift Used: 3.0 Uses 3.0 if Relative Shift >3 N-Value: 11 N-Value+20%: 14 2 FSS Storage Cell E-3 f 8300303

FINAL STATUS SURVEY F8300303 Survey Results:

A total of 15 direct measurements were made in F8300303. 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. One alpha swipe indicated removable levels of alpha radiation at a location where the paint was peeling. This area was investigated via additional swipes, alpha/beta static measurements, and use of in-situ gamma spectroscopy. No additional removable contamination was identified and static measurements were consistent with background levels. The results of the in-situ gamma spectroscopy indicated the contaminant was thorium 232. It was postulated that the thorium was a component of the construction material and the swipe had collected a small portion of the concrete dust giving rise to the elevated alpha levels.

Swipe data did not indicate elevated activity levels above the MDA.

Table Z, Static Measurement Results

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  • .,"-.- ,,,. .-_ -,* .* ,',, a~p-~: ,. '_-,:':. ,- -E3etii' (cptn}; -.
*,.J 1 F8300303X00001 276 2,091

- - -2 F8300303X00002 -.. - 264 - . - 2,000 3 F8300303X00003 286 2,167 4 F8300303X00004 256 1,939 5 F8300303X00005 285 2,159 6 F8300303X00006 268 2,030 7 F8300303X00007 286 2,167 8 F8300303X00008 318 2,409 9 F8300303X00009 259 1,962 10 F8300303X00010 269 2,038 11 F8300303X00011 277 2,098 12 F8300303X00012 261 1,977 13 F8300303X00013 265 2,008 14 F8300303X00014 281 2,129 15 F8300303X00015 283 2,144 Table 3 contains the statistical summary of the static measurement data for the Storage Cell E-3.

Table 3, Beta Summary Statistics Beta Static Storage Cell E-3 Mean 2,088 Median 2,091 Standard Deviation 118 Minimum 1,939 Maximum 2,409 Count 15 3 FSS Storage Cell E-3 F8300303

FINAL STATUS SURVEY F8300303 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: 2,091 Mean: 2,088 Static Data Standard Deviation:
  • 11 a Maximum: 2;409
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Adjusted N Value: 1'4 S+ Value: .* ..15

  • ** -- ** ** * * * - Critica1va1ue: * -fo- --

Sufficient samples collected: P~s*s

  • Maximum value <DCGLw: Pass*

Median value <DCGLw: Pass*.

Mean value <DCGLw: Pass Maximum value <DCGLemc: * 'NtA Sign test results: Pass*

The survey unit passes all conditions: Pass Survey Unit Investigations and Results:

Investigations were required for the quality control survey package associated with this final status survey unit. The results are discussed in Attachment 3 Investigation.

ALARA Statement:

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 E-3 f 8300303

FINAL STATUS SURVEY F8300303

==

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.

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 F8300303 meets the release criteria of 10CFR20.l402.

J 5 FSS Storage Cell E-3 F8300303

Attachment 1 Maps December 13, 2016 Survey Unit F8300303

I

- A- I A-2 A-3 F830030'.JJ<0007 ~

I o 2 167d~m/100 CM' 8-l 8-2 B-J f

  • 30030~X!l009 Ce II Stora geC-J I ; 196~ pm/100cr-~

C-1 C-2

().T 0-2 0 -J E-1 E-2 E-3 F8J00303X0003 +

..____ 11= 2 lC dpm1100 cm' F8300303XOOO 1 jl

  • 2.091 dpm ~OO cm' F8J00303XO F8300303X0013 z p* 1 ~.,g f.\?ml100 cm'

$i*

  • 2 ooa dprn 100 cm' F3300303XOO ~ $fA300JO

, 1 939 ill>f'\1100 C'1'r I = Z 144 dp1n,100an' I

F8300303X001'.? $F JOOJ03X0008

~ I'= 1 977 .Jpm/100 cm' ll 2 A09 :lprn11 1 cm*

F8300303XOOOG +

' '

  • 2 030 opnv100 an* ~F8'.l00303XCX 14 fe;)0031 )3 (0002
    • s 2 ,29..c...... *1100cm' ~ $ r- =
      ? 00 o 1pm1100 on' Refe~Polnt

~

FS300303X001 t

r. - :!.09adpll'J OOcm' sMuall TIDEWATER INCI.

RAO oL.oG1CAL Sc,,,.,,cu INTERIM 0HsrTE STORAGE 6UIU>ING (1056) r_., *o.:

SMUD Location: ~1 cho S-Xo AppnNOd b)<

T- HnaJ Stoltus.

Ora"'"'

- No.: 105o8 f'.in*l Shtn Sl.Jnte.. 0030..>J<0010 eeu £- ' ,....._ __ _ w... l, - ---1u 0 I;) j; 2()

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dale

=

  • 031\ dpmt' ac cm'

$ " 5Ue itif:,,."1 27 Dale Jel82616 Rew No. :

Page I Att. I Maps F8300303

Attachment 2 Instrumentation December 13, 2016 Survey Unit F8300303

Table 2-1. Survey Unit Instrumentation

  • 'M~asurement
  • Miniinum:Detectabie A~tivity". *Detector Calibt'.ation

' Typ~ * * *

  • Jn~frum~nt.Typ.e Due Da.teb Efficien~ies.

Beta Static Ludlum Model Beta - 506 dpm/I 00 cm 2 13.2% 3 I 7897/331972 Measurement 2350-1 2/10/17 Ludlum Model 44-1 I 6 B Detector Swipe Ludlum Model 2929 Beta - 76 dpm/100 cm2 43.4% l I 82597 /188736 Measurements Ludlum Model 44- 5113117 10-1

  • 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.

cm 2 = square centimeters cpm = counts per minute dpm = disintegrations per minute Page 1 Att. 2 Instrumentation f 8300303

Static Measurement MDA Variables Beta Survey Type PR331972 Detector Number 188 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

Where: Br Background Countrate t Count Time (min)

E Efficiency A Area of detector (cm 2)

Static MDA 506 dpm/100 cm 2 Page 2 Att. 2 Instrumentation f 8300303

Attachment 3 Investigation December 13, 2016 Survey Unit F8300303 Att. 3 Jnvestigation f 8300303

Final Status Survey Data Investigation/Evaluation FSS Package No. 18300303 Date:l 11-14-2016 Location/Description: IOSB Storage Cell E-3 (QC Survey Package Data)

Instrumentation Involved: (include serial numbers) NIA Data Investigation:

PROBLEM- Elevated alpha and beta results were observed for sample ID Q830030-10 swipe from the QC package for IOSB Storage Cell E-3. Initial FSS results for this same sample location revealed results typical of those demonstrated throughout the IOSB FSS.

RESOLUTION-Recount of swipe sample resulted in continued elevated gross alpha results and diminished beta results. Multiple recounts of swipe results in same elevated alpha and near background beta results.

Gamma spectrometric analysis (qualitative only) was performed with no nuclides of concern(per LTP) identified following sample count of the swipe. The gamma spectroscopic analysis resulted in identification of Th-232 and Ra-226 via gamma emitting daughter products, both are alpha-emitting nuclides. No further action necessary.

Resurvey of subject area, Q8300303-10 was performed per instruction below and revealed satisfactory results of the area for 32 beta static measurements and 32 swipes of the entire 0.37m 2 area.

Data Evaluation and Investigation Resolution:

The suspect area (0.37 m 2 ) will be resurveyed and the results presented to the FSS/LFSSRE for review and resolution.

1. Sample area Q8300303-1 O will be divided into a grid of 100 cm 2 increments, total 32 areas.
2. Each of the 32 locations within the grid will have a unique identifier,
a. a static count performed for 60 seconds and
b. a swipe sample obtained.
3. All of the swipe samples will be analyzed the same as the first (F8300303) FSS package and the second (Q8300303) quality control package, using the Ludlum 2929 gross alpha beta counter.
4. Results of the static counts of each area along with the results of the swipe samples will be submitted to the FSS/LFSSRE for review and evaluation.
5. This investigation report will be submitted to the LFSSRE for review and a copy included in both the FSS package (F8300303) and the quality control package (Q8300303) along with a copy of this DEC-045 Final Status Survey Data Investigation/Evaluation.

fKI Acceptable for use and inclusion in Based on the above resolutiO/ , the survey data is FSS Package determined to be: I 0 Not Acceptable for use

\...../ I II Prepared by: / ~\.._ ~ ()._6_ FSSE Date 11-14-2016 LFSSRE Date 11-16-2016 DEC-045, Rev. 0 Page 1 of 1

Attachment 4 Data Assessment December 13, 2016 Survey Unit F8300303

1 Histogram for Beta Static Activity (dpmf100cm2) E*3 Act~

' Nl¥lbefol'VMi 15'

/~

Minii'un 1,939.J'Jj M..m.m 2.409091 so Skewness 11~~~!

2851 fi?IMMn 2.007 83 1 1

I {;'JM""'" 20!ll.91

. I

. 0NOfmai0ietrbiiM

// OLessBrlf 01t10fe8nt 1 1 1973 2020

  • 2007 21 14 2161 nos

___o_ _

2255 nl2

__o ___

2348

.1 2395 Page 1 Att. 4 Data Assessment F8300303

Q-Q Plot for Beta Static Activity (dpm/100cm2) E-3 Activty N *15 MeM*.208l:l Sd*118.2:

Slope* ll'i7 lnt~Cepl *2CQ1 Cau.*il&I~. R

  • 0.935
  • BeitFitl.inc 2100 1040

""° II I . *1.5 -1.0 -05 oo o.51 1.0 1.5

[~~~~~~~~~~~~~~~~~~~~~~~~~-Th_e_o_re_ti_ca_1_ou_a_n_H1_e*_<_st_an_d_fil_d_N_o_rm_m_>~~-;...~~~~~~~~~~~~~~~~~~~~~~~~~--'

Page 2 Att. 4 Data Assessment j F8300303

Smear _Data_ Calculation_Sheet_10131~

IOSB Final Status Survey i I.Cl LC2 LC3 LOI LC6 LCS flCPM fldpm Date/Time of Count Sample Comments I F830 030 3 x 00001 SM Cell E-3 44 -6 10/.14/16 0945 2 F830 030 3 x 00002 SM Cell E-3 48 3 10/,14/16 0947 3 F830 030 3 x 00003 SM Cell £-3 54 17 I0/,14/16 0948 4 Fl:130 030 3 x 00004 SM C"ll E-3 46 -2 10/14/16 0950 s F!l30 030 3 x 00005 SM Cell E*3 56 21 10/14/16 0951 6 F830 030 3 x 00006 SM Cell E*J 48 3 10/114/16 0952 7 FKlO 030 .1 x 00007 SM Cell E-3 39 -18 10~14/lG 0953 8 F830 030 3 x 00008 SM Cell E-3 47 1 10/14/16 0954 9 F830 030 3 x 00009 SM Cell E-3 45 -4 10/,14/16 0956 10 F830 030 3 )( 00010 SM Cell E-3 42 -11 10h4/16 0958 11 F830 030 3 x 00011 SM Cell E-3 39 -18 10~14/16 0959 12 F830 030 3 x 00012 SM Cell E-3 117 l 10/14/16 1000 13 F830 030 3 x 00013 SM Cell E-3 45 -4 10/14/16 1001 14 F830 030 3 x 00014 SM Cell E-3 47 1 IO/illl/16 l.003 15 F830 030 3 x 00015 SM Cell E*3 SS 19 10/i14/16 1004 Commcmrs By ~ign:itun:~ below~ the required source check and background checks were satisfactorily pC'rform('(f prior to use of lhe instrument identified below.

I

~udlum 2929 Benchtop Instrument bJ:t:

I t~lfi(it*11.:-r ulfl Cl1Unl 2929 S/N: 182S97 rare {*n1C* MIM Ul)IV/01

(.( 0.364

~ A 43-10-1S/N:18873~ cpm min dJ)Oi (:11-:'f ;ll'C.'.'l Tech A Sip,n/ D<itc ;!'°/ /_,., ; r fVf/JJJc. /2-1.-lfo 46.7 l 76.).

- Cal Due Date: 5/13n017 f1 0.~3~

Tech 13 Sign/ Date N/1<. cµm min (1pn11n*1.-:11:;1 Page 3 Att. 4 Data Assessment f 8300303

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