ML17065A057

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Final Status Survey Summary Report, January 5, 2017, Iosb DAW Staging Bay Class 1, Survey Unit F8300031
ML17065A057
Person / Time
Site: Rancho Seco
Issue date: 01/10/2017
From:
Sacramento Municipal Utility District (SMUD)
To:
Office of Nuclear Material Safety and Safeguards
Shared Package
ML17065A032 List:
References
DPG 17-038
Download: ML17065A057 (16)
v • d • e


Text

Rancho Seco Final Status Survey Summary Report January 5, 2017 IOSB DAW Staging Bay Class 1 Survey Unit F8300031 FSS Engineer Approved By:..d>,~ Date:

Manager, Rancho Seco Assets 16"17c,7

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FINAL STATUS SURVEY F8300031 Su..Vey Unit:

F830003 l, Interim Onsite Storage Building (IOSB) DAW Staging Bay 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), the IOSB contained and 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 DAW Staging Bay, two elevated areas were identified on the floor. One of these areas exceeded the DCGLw but not the DCGLEMC. This area required remediation. The other area did not exceed the DCGLw. The DAW Staging bay was divided into a small Class 1 Survey Unit, buffered by a Class 2 Survey Unit.

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 10 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 less than one square meter (0.74 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 randomly determined and approximately 100% of the area scanned. The instrumentation used for the survey along with the MDC values are listed in Table 2-1.

FSS DAW Staging Class 1 F8300031

FINAL STATUS SURVEY F8300031 Table 1, Survey Unit Design Parameters i;v~tuatioriJnllGfvafti~s* * **

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Survey Package:

F830 DAW Staging Bay Class 1 Survey Unit:

03 Class 01 SU Area (m2) 01 Evaluator:

JR DCGLw:

43,000 Gross Activity DCGL Area Factor 15 DTBD-05-003 Desiqn DCGLemc (dpm/100cm2):

640,700 DCGLemc:

640,700 LBGR:

21,500 Default = 50% DCGL Siqma:

598 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 From 10/26/16 Survey Total Area Scanned (m2):

0.74 Scan Coveraqe (%) ~:,,/~\\':1~0d%1! Class 1 Choosing 'NIA' sets material Material Type:

N/A background to "O"

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Z1-<X:

. :~.645 Z1-o:

f.645 Siqn p:

  • o.99865
  • Calculated Relative Shift:

35.9*

Relative Shift Used:

  • 3.o*

" Uses 3.0 if Relative Shift >3 Values selected based upon N-Value:

5 Judqement Values selected based upon N-Value+20%:

5 Judqement 2

FSS DAW Staging Bay Class 1 F8300031

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FINAL STATUS SURVEY F8300031 Survey Results:

A total of 5 direct measurements were made in F830003 l. 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.

. SarnpieJ.*

    • . *Beta (cpm)
  • . B~t~,(dpm) 1 F8300031C00001 288 2,233 2 F8300031C00002 304 2,357 3 F8300031C00003 305 2,364 4 F8300031C00004 282 2,186 5 F8300031C00005 509 3,946 Table 3 contains the statistical summary of the static measurement data for the DAW Staging Bay Class I.

Table 3, Beta Surimiary Statistics Beta Static DAW Staging Bay C.lass 1 Mean Median Standard Deviation Minimum Maximum Count Survey Unit Data Assessment:*

2,617 2,357 747 2,186 3,946 5

The survey design required 5 static measurements based upon the size of the survey unit (0.74 m2). Following the guidance in MARSSIM Section 4.6, these values are compared directly to the DCGLw. The data collected from location F830003 l C00005 while less than 10% of the DCGLw was collected over a crevice. In order to evaluate the effect of the crevice on the resulting data, the guidance contained in Section 6.2 of DTBD 06-006 was followed and a follow up evaluation was performed using a gamma sensitive sodium iodide detector (Ludlum model 44-10). The results of the investigation confirmed no levels of residual radioactivity in excess of the DCGL. Attachment 3 contains the results of the investigation.

The comparison and the results are presented in Table 4. The sample mean and median values were less than the DCGL.

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FSS DAW Staging Bay Class 1 F8300031

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FINAL STATUS SURVEY F8300031 Table 4, Data Assessment Results Number of Samples:

  • . '5 Median:

2',3!:i7 Mean:

  • 2,61}.

Static Data Standard Deviation:

74T

  • Maximum:

3;946 Sufficient samples collected:

Pass Maximum value <DCGLw:

Pass Median value <DCGLw:

Pa~s

  • Mean value <DCGLw:
  • . P.ass.

Maximum value <DCGLemc:

Ra$s Sign test results:

NIA

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  • The survey unit passes all conditions:

Pass Survey Unit Investigations and Results:

An investigation was required for follow up to direct beta measurement F8300031 C00005 to evaluate response in relation to a crevice. The results are contained in Attachment 3.

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 1 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 1 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. Investigation, performed per Attachment 3 results 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 F8300031 meets the release criteria of 10CFR20.l402.

4 FSS DAW Staging Bay Class 1 F8300031 Maps January 6, 2017 Survey Unit F8300031

SMUD ~

TIDEWATER INC

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ST AGING BAY CLASS on a.:

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alk:

App"""9d by.

SMUD Orawlng No.:

Oeoerlptlon:

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  • Oat.o:

Appro><>I dote:

R.. No.:

Page I

(+/-) F8300031 COOQ04 13 = 2, 186 dpmn oo cm 2

(+/-} F8300031C00001

!3 = 2 233 dpm/100 cm2

{+/-) F8300031 C00003

~ = 2,364 dprn/100 cm 2 F8300031Cp0002 P :::: 2,357 dl)m/100 cm2

{+/-) F8300031C00005 13 = 3.946 dpm/100 crti2 Att. I Maps F8300031 Instrumentation January 5, 2017 Survey Unit F8300031

Table 2-1. Survey Unit Instrumentation Beta Static Measurement Swipe Measurements Ludlum Model 2350-1 Ludlum Model 44-1 16 B Detector Ludlum Model 2929 Ludlum Model 44-10-1

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  • Miniqi~m D~tecfable Activ\\t)*~.

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  • - :.Efficiencies.*
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Beta -

454 dpm/I 00 cm2 12.9%

Beta - 78 dpm/100 cm2 43.4%

Calib1:ati.o.'1 t>ue.i;>a_t_e~.

317899/331973 2/10/17 1825971188736 5/13/J 7

  • 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 F8300031

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Static Measurement MDA Beta Survey Type PR331973 Detector Number 143 Background count rate (cpm)

Count Time (min) 0.129 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

Where:

. Br Backgr.ound_Countrate t

Count Time (min)

E Efficiency A

Area of detector (cm2)

Static MDA 454 dpm/100 cm2 Page 2 Att. 2 Instrumentation F8300031

Att. 3 Jnvestigation Investigation January 5, 2017 Survey Unit F8300031 F8300031

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Final Status Survey Data Investigation/Evaluation FSS Package No.

X8300031 I Date:

I 11-29-2016 Location/Description:

F8300031 IOSB Stage Bay CLASS 1 post remediation Instrumentation Involved: (include serial numbers) NIA I

Data Investigation:

REASON:

During execution of F8300031, an elevated static (BD-*beta direct) measurement above a floor crevice in the TOSS Staging Bay CLASS 1 resulted at location F830003 I C00005.

These instructions will provide the data necessary to properly evaluate this elevated measurement location.

SURVEY INSTRUCTIONS:

./

Using a calibrated 2350-1 and 44-10 (2"x2" sodium iodide) detector, obtain a one minute gamma direct (GD) measurement in the same location (F8300031 C00005) as the elevated beta direct measurement obtained in the execution of package F8300031.

Data Evaluation and Investigation Resolution:

l. Log.tlu:.resulfs ofth-eGD measui*enien*t below along ~vith instn1ment and detector serial number, calibration due date and the 2350-1 download file name.
2. Sign and date pe1formance of the survey.

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REFERENCE:

Poc soct;on 6.2 om TB D-06-006 'IMted m"'""m<ms w; II b< ;nm_o~~";tt 44-1 O Mtwo,,

collnnated to a 20,000 cpm cntenon.

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INVESTIGATION LOCATION ID F830003COOOOS RESULTS:

q Co'-/ 0 gross counts.

~12.Q bkg counts.

z o 1 r. 11 2 L 1; 3

  • oo download file name t1-IZ9 /1 c..

2350-1 S/N 3176'9:t Detector S/N

.2088Jt.

Cal due di!te

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PERFORMED BY:

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lul...zq[tt.

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I i0/A Technician A Dat~

Technician B Dale

)(Acceptable for use and inclusion Based on the above resoh ion, the survey data is determined t~: AA in FSS Package D Not Acceptable for use Prepared bv:

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FSSE Date 11-29-2016

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Reviewed by:

LFSSRE Date l l-29... :1Q)6

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DEC-045, Rev. 0 Page 1 of 1 Att. 3 Investigation F8300031

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Data Assessment January 5, 2017 Survey Unit F8300031

Histogram for Beta Static Activity (dpm/100 cm2) DAW Staging Bay C!ass 1 2640 2816 3167 3343 3519 Page I Att. 4 Data Assessment F8300031

Acliviy N~olVok.lds Mril'Ull Mtm1un SD s\\

2.186.051 3.9'5. 7~ 1 746.78.

Skewneu 2-18 Kut1uis 4.79 0Mean 2,61705; G'J M°"'"

2.356.59, B*loimalOil'lthit.ion Ole"Sm 0M01eON

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  • l.2 Q-Q Plot for Beta Static Activity (dpm/100 cm2) DAW Stagirlg Bay Class 1

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-0.3 no n:1 Q6 Theoretical Quantile& (standard NormaQ Page 2 Att. 4 Data Assessment Q9 1.2 F8300031 AclivilJ MMn*'2617 Sd*74S.B S~*GSl.3 lnlcir:ept.*2617 Co11cWion. A

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'I Smear _Oata _ Calculat ion_Sheet_lOl 316 IOSB Final Status Survey I.Cl LO l.C3 LOI LC6 LCS

[ICPM lldpm Date{Time of Count Sample Comments I

F830 003 l

c 00001 SM SlJ8C' Bay Floor 48

-1 l 1/29/16 J !09 2

F830 003 1

c 00002 SM St;igc 0Jy Floor 48

  • 1 11/29/16 1111 3

FS30 003 1

c 00003 SM Stag12 Bay Floor 51 6

ll/29/16 1112 4

F830 OOJ I

c 00004 SM Stage Bay Floor 38

. *24 11/~9/16 11.13 5

FSJO 003 I

c 00005 SM SlJG<' BJy Floor 45

-8 ll/i!9/16 11.15 (j

F830 003 I

(

00006 SM Stag*~ Bay Floor.-><.

7 F830 003

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c 00007 SM Stase ri~v Floor

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R F830 003 I

c 00008 SM Stage Bny Floor >< ><

9 F830 003 I

c 00009 SM Stage: £l.-ry Floor

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=::::><:::::

10 F830 003 l

c 00010 SM St.igc: Bay Floor

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11 F830 003 l

c 00011 SM Stage Bay Floor

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12 1'830 003 l

c ooou SM Stage Gay Floor >< ~

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l3 F830 003 1

c 00013 SM Stage Bay Floor..><,::::><:::::

14 FS30 003 I

c 00014 SM Stai;:c Boy Floor 15 FSJO 003 1

c 00015 SM Stage O<ly Floor..:>< ::>< ~

Cornrnents l\\v ~e11.iturc~ bt.iaw*. the: rcqu1r<.-d !iourcc cht.-ck i.lrtd bacq..round chcr.t.:!. Wl~rt" o,aLi!>fiJctorilv oerforrned prior to u~ of 1he irhtf'un1t~nl i1h~n1illr-ct bt'low.

Ludlum 2929 Bcnchtop Instrument lJY.l:

(*lfi(it:n...:y

bkr,

((lun(

2929 S/N: 182597 rt1W tint**

MDA 0.364 llDIV/01 a

I 43-10-1 S/N: 188736 cpm mm domPl"r a1c.,

Tech A Sign/ Dale /L. '11.,... ;,/; 1. 1-1 I..

al Due Date: 5/13!2017

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48.S I

77.6 Tech B Sign/ Date f N11A 0.434 r:pm min dpnipnJrr.;1 Page 3 Att. 4 Data Assessment F8300031

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