ML17065A046

Final Status Survey Summary Report, October 21, 2016, Iosb Exterior Surfaces, Survey Unit F8300313

ML17065A046
Person / Time
Site:	Rancho Seco
Issue date:	01/26/2017
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: ML17065A046 (15)

Text

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Rancho Seco

_f.irial Status Survey Summary Report October 21, 2016 IOSB Exterior Surfaces Survey Unit F8300313 Approved By:

FINAL STATUS SURVEY F8300313 Survey Unit:

F8300313, Interim Onsite Storage Building (IOSB) Exterior Surfaces 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's storage cells possibly stored media of many types, including filters, resins, contaminated chemicals, DAW, activated reactor components, contaminated plant components and other contaminated items. This survey unit is the vertical exterior surfaces of the IOSB excluding the roof area.

Site Characterization: Section 5.2.2 of MARSSIM identifies the historical site assessment (HSA) data and professional judgment to be used for the evaluation of potential for residual contamination. Based on this evaluation of the IOSB exterior (vertical only) surfaces and the minimal potential for contamination, this survey unit was designed for final status and the area was designated as a Class 3 area.

Survey Unit Design Information:

The Survey Unit Design Parameters are presented in Table 1. The survey unit and measurement locations are depicted on the maps in Attachment 1. Static measurement locations were randomly determined and approximately 1% of the area scanned. The instrumentation used for the survey along with the MDC values are listed in Table 2-1Attachment2.

FSS Exterior Surfaces F8300313

FINAL STATUS SURVEY F8300313 I

Table 1, Survey Unit Design Parameters

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Survey Packaqe: F830 IOSB Exterior Surfaces Survey Unit: 031 Class 3 SU Area (m2) 2750

(::valuator: EG DCGLw: 43,000 Gross Activity DCGL Area Factor NIA Class 3 Design DCGLemc (dpml100cm 2 ): NIA Class 3 DCGLemc: NIA Class 3 LBGR: 21,500 Default = 50% DCGL Sigma: 175 Survey Data Type I error: 0.05 Type 11 error: 0.05 Predominant Nuclide Cs-137 Sample Area (m2) NIA Total Instrument l;fficiencv: 0.129 Total Area Scanned (m2): 27.7 Scan Coverage(%) *.':.J::;::MM, Class 3 Choosing 'NIA' sets material Material Type: NIA background to "O"

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Z1-a: 1.645 Z1-a: 1.645 Sign p: 0.99865 Calculated Relative Shift: 122.8 Relative Shift Used: 3.0 Uses 3.0 if Relative Shift >3 N-Value: 11 N-Value+20%: 14 2 FSS Exterior Surfaces F8300313

FINAL STATUS SURVEY F8300313 Survey Results:

A total of 15 direct measurements were made in F83 00313. 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 was not obtained in this survey unit, therefore no swipe data is included in Attachment 4.

Table 2, Static Measurement Results Number I Sample# Beta (cpm) Beta.(dpm) 1 F8300313C00001 305 2,364 2 F8300313C00002 259 2,008 3 F8300313C00003 284 2,202 4 F8300313C00004 220 1,705 5 F8300313C00005 272 2,109 6 F8300313C00006 268 2,078 7 F8300313C00007 268 2,078 8 F8300313C00008 290 2,248 9 F8300313C00009 252 1,953 10 F8300313C00010 268 2,078 11 F8300313COOO 11 267 2,070 12 F8300313COOO 12 270 2,093 13 F8300313C00013 249 1,930 14 F8300313C00014 293 2,271 15 F8300313COOO 15 307 2,380 Table 3 contains the statistical summary of the static measurement data for the Exterior Surfaces Table 3, Beta Summary Statistics Beta Static Exterior Surfaces Mean 2,104 Median 2,078 Standard Deviation 175 Minimum 1,705 Maximum 2,380 Count 15 3 FSS Exterior Surfaces F8300313

FINAL STATUS SURVEY F8300313 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

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Number of Samples: 15 Median: 2,078 Mean: 2,104 Static Data Standard Deviation: 175 Maximum:

Adjusted N Value: 14 S+ Value: 15 Critical Value:

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Sufficient samples collected: Pass Maximum value <DCGLw: Pass Median value <DCGLw: Pass Mean value <DCGLw: Pass Maximum value <DCGLemc: .

• N/A Sic::in test results: . Pass The survev 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 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. No potential areas of elevated activity were detected.

==

Conclusion:==

The FSS of this survey unit was properly designed as a Class 3 survey based on the scoping evaluation. The required number of direct measurements was made and the scan 4 FSS Exterior Surfaces F8300313

FINAL STATUS SURVEY F8300313 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 F83003 l 3 meets the release criteria of 10CFR20.l402.

5 FSS Exterior Surfaces F8300313

Attachment 1 Maps October 21, 2016 Survey Unit F8300313

F8300313C00010 J3 =2,078 dpm/100 cm 2 E17 F8300313C00012 F83003.~ 3C00003 Ei F8300313C00004

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J3 =2,093 dpm/100 cm 2 J3 =2,202 dpm/100 cm 2 J3 =1,705 dpm/100 cm 2 I

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F8300313C00009 I

J3 = 1, 953 dpm/100 cm 2 HS300313C00005

_,. p  :::i2, 109 dpm/100 cm 2

~ F8300313C00006 J3 =2,078 dpm/100 cm 2 F8300313C00015

) J3 =2,380 dpm/100 cm 2 l'1' F8300313C00002 F8300313C00007 F8300313C00014 '

J3 =2,008 dpm/100 cm 2 J3 =2,078 dpm/100 cm2 J3 =2,271 dpm/100 cm 2

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F8300313C00001 F8300313COOO 11 F8300313C00013 J3 =2,364 dpm/100 cm 2

• J3 =2,070 dpm/100 cm2 F8300313C00008 J3 =1,930 dpm/100 cm 2 J3 =2,248 dpm/100cm2 1058 ExTERIOR SURFACES Contract No.: 4500091426 SMUD

~L~oc~oti~on::_:--i:R:::,:an:.::,ch:.:'.._o,::.::Se.:.::co_ _ _--1 Approved by.

Task: Final Status Drawing No.: . IOSB Final Status Surve

Description:

IOSB Exterior Drown B .

• c ra QC'd: . J Reese Approval dote:

Dote: 10062016 Page 1 Att. 1 Maps F8300313 Rev No.: 1

Attachment 2

'Instrumentation October 21, 2016 Survey Unit *F8300313

Table 2-1. Survey Unit Instrumentation

• M:easu,reijient Miniintim DetectabteActlvity". Dete,ctcir C.ali!>ration

• instrulnent

.* Type

.. T~r.e '*: . . ., Efficief!cies,. . 'Due l)a.~eb Beta Static Ludlum Model 2350-1 Beta - 500 dpm/100 cm 2 12.9% 317899/331973 Measurement Ludlum Model 2/10/17 44-116 B Detector

• 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 F8300313

Static Measurement MDA Variables Beta Survey Type 331973 Detector Number 175 Background count rate (cpm) 1 Count Time (min) 0.129 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)

Background

Where: Br Countrate t Count Time (min)

E Efficiency A Area of detector (cm2)

Static MDA 500 dpm/100 cm 2 Page 2 Att. 2 Instrumentation F8300313

Attachment 3 Investigation October 21, 2016 Survey Unit F8300313 (none required)

Attachment 4 Data Assessment October 21, 2016 Survey Unit F8300313

Histogram for Beta Direct Activity (dpm/100cm2) lOSB Exterior Surfaces IActivity Nun- ~r of Valu~s r r. .linimun*

M~xjn*um so 1.705A~

£.379.&'.

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Ske~-r e:ss -0 . ~1 Kurtosis 0.791 B Meo 2.10' 391 B Mo::1iar 2.07752 5

B Mcrn*:I Distribution O L~s Bm>

0 Mere E.in>

821 1888 1?56 2023 Dato R-> n;;e

£091 2158

• ms 2293 £360 Page 1 Att. 4 Data Assessment F8300313

Q-Q Plot for Beta Direct Activity (dpm/100cm2) IOSB Exterior Surfaces Aclivily N =.15

• Mean =2104

&*174.5 Slope= 177.5 2300 Intercept= 2104 Correlatior" R =0.971 l!I BeorFit Line 220()

1700 *

-i.5 -1.0 -0.5 0.0 0.5 1.v i.5 Theoretical Quantiles (Standard Normal)

Page 2 Art. 4 Data Assessment F8300313