Rancho Seco

Final Status Survey Summary Report

October 21, 2016

IOSB Storage Cell C-1

Survey Unit F8300223

FSS Engineer

Lead FSS Engineer

~ ./.il Approved By=--~~---~~z;;;..a.: .... _~..;;;..=~-- Date:

Manager, Rancho Seco Assets

.,

FINAL STATUS SURVEY F8300223

Survey Unit: F8300223, Interim Onsite Storage Building (IOSB) Storage Cell C-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: 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 beta activity level of 2,0421100 cm2 and a maximum value of 2,506 dpm/100 cm2

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

Survey·unif o-esigrflnformatio·n-:·---- -- ------ ---------- --- -- -- --------- - ---- --·- --------·------ -·

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 33% of the area scanned. The instrumentation used for the survey along with the MDC values are listed in Table 2-1. Attachment 2.

FSS Storage Cell C-1 F8300223

FINAL STATUS SURVEY F8300223

Table 1, Survey Unit Design Parameters

·.·:-

Survey Package: F830 StoraQe Cell C-1 Survey Unit: 022

Class 3 SU Area (m2) 23.1

Evaluator: JR

DCGLw: 43,000 Gross Activity DCGL Area Factor N/A Class 3

Design DCGLemc (dpm/100cm2): N/A Class 3

DCGLemc: N/A Class 3 LBGR: 21,500 Default= 50% DCGL Sigma: 198 ScopinQ Survey Data

Type I error: 0.0.5· Type II error: 0.05

Predominant Nuclide Cs-137

Sample Area (m2) N/A Total Instrument Efficiency: 0.129

t===-==~·-=-===-=· =-=-==="""-=t====l=========~=--1.-----·-- .. _ ·----------· ... Total Area Scanned (m2): 7.51

Choosing 'N/A' sets material Material Type: N/A background to "O"

.,,,·_;;:/ \:~71:<1:,;::,~ ?;;caiC:U'i~i~Clc:ii~fu~[2:::::,<;;;%:';~)~n:~;=,;:: '.°t:f/!!{'.;';:;r:..;:r;::nc:<>mme·iJts~.-,'.:{): \ .y:::;>: :;. Z1-a: · ·. 1:645

Z1-B: 1.645 SiQn p: 6:99860

Calculated Relative Shift: -·. ·108~5 Relative Shift Used: 3:0 Uses 3.0 if Relative Shift >3

N-Value: · ··11 N-Value+20%: · . : '14'

2 FSS Storage Cell C-1 F8300223

FINAL STATUS SURVEY F8300223

Survey Results: A total of 15 direct measurements were made in F8300223. 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

~ .. •. ... , ....... . ·•·'"1·:·."· .. :;·, .. • . · .. , .. ; ' . . ' . . .

·· .r:.fombei:·•· .. . . ·r~mP;l~J . : . ·.~ ·Beta (cpni)' . .. IM~.a.(qPinr· · .. :'' . . ' ·: .......... : ·~ :.'. )· '' ·.··. ·.·. . .. 1 F8300223X00001 218 1,690 2 F8300223X00002 246 1,907

3 F8300223X00003 268 2,078 4 F8300223X00004 243 1,884 5 F8300223X00005 252 1,953 6 F8300223X00006 244 1,891

7 F8300223X00007 247 1,915

-·- -·-··-·· ___ _8 _ _ E8.3-0.0223X0_0_0.08 _______ -···-·-- ____ 259 _____________ _ _____ 2,000--·--- - .

9 F8300223X00009 244 1,891 10 F8300223X00010 253 1,961 11 F8300223X00011 205 ·1,589

12 F8300223X00012 244 1,891 13 F8300223X00013 223 1,729 14 F8300223X00014 236 1,829 15 F8300223X00015 235 1,822

Table 3 contains the statistical summary of the static measurement data for the Storage · Cell C-1.

3

Table 3, Beta Summary Statistics

Mean Median

Beta Statics Cell C-1

Standard Deviation Minimum Maximum

Count

FSS Storage Cell C-1

1,869 1,891

124 1,589 2,078

15

f 8300223

FINAL STATUS SURVEY F8300223

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

...... · .Co1T1nwot~' ···· Number of Samples: 1s'

Median: 1,891 • Mean: 1;869.

Static Data Standard Deviation: · .. 124. Maximum: 2;07:8 :·

·:Lg,;:' ,·.:~;;;s~r::;-;::s'iaa:;t.~$.f ;Re.~:~H$:':x::;;;;:~;.1t~\~;:z~:~}~:vh ,~;[.;.T.J: ;::::::\ •;.¢'9rnm~ot~: :.: .... ::';/ .· .r •. ·; :' .. :.· Adjusted N Value: · 14'

S+ Value: . ·1 S . Critical Value: 10 ·

.:f:(;· ·· '·.::;?·:.·: . .-c· r·1't'e'."r"ia 1Satfs'fa'dio· 11·:·.;_::•.:\'. .<·:·:~._,..,,.;:;:\ '.. ,>.;>·· ·," ::c·: .. ·.0··.·m···.···.m·.·'.''.·e'."n·.·t·.·.·s" .. /·.·: ........ , ... .. I::.::· .. \_..-. - - . ;. - ~· -· .. ·-·-··. ·-- ,. ... -- . - - . - -- - ..... --.-··-. ,:~;·:J;-_:·r.~- ·:· •.... _. :::_:;-.. . -,_ --.·,,,_ ': .

Sufficient samples collected: , .Pass· ------·--·--· - ··----------------------------------------- ....:....:..:..~ ---. ----------··-···---- -----·-·--·· -----··--· -- ---- -- ..

Maximum value <DCGLw: Pass ' ..

Median value <DCGLw: Pas$. Mean value <DCGLw:

Maximum value <DCGLemc: ... : NIA· Siqn test results: F?as:~r~

::!:}t·c~'·/:'::.}':.~:;.:.~y;;:{'.t~'in~i'.'.$.t~Jli~:<':}:;:;:::-~;~;;;;;~.'..??f'.f%i· .;{:'.(.,!~/i;.:'t)qQ'.rifrri~·iJts.'//'.)>, '· ···· 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 3 survey and the sample results are consistent with that classification. The variability of the swvey results was lower than the characterization data used for survey design. No potential areas of elevated activity were detected.

4 FSS Storage Cell C-1 F8300223

FINAL STATUS SURVEY F8300223

Conclusion: I

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. 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 conclud,ed that survey unit F8300223 meets the release criteria of 1OCFR20.l402.

5 FSS Storage Cell C-1 F8300223

Attachment 1

Maps

November 8, 2016

Survey Unit F8300223

Reference Point ror North ,, Upper Wall

F8300223X00010

II $~ = 1.961 dpm/100C h' N ......_ A·1 A-2 A-3 II

"* F8300223X00007 $

B·1 e,.2 B-3 ~ = 1 9 15 dpm/100 cm'

CE II Store geC-3

II C-1 C-2

D-1 0·2 D-3

E-1 E-2 E-3 II II 11

t--11

II II

f8300223Xooo15$ ~ -~

~ F8300223X00008

1: ~ = 1.822 dpm/100 Clll'

~F8300223X00003 P = 2.000 dpm/100 cm'

F8300223XI ~ ~ I ll = 2.078 dpm/100 cm' ~fl = 1,891 d! /100 an• $ r8300223X00004

F83CX :23X00006~ F8300223X00002 l' = 1.884 dpm/100 cm'

p = 1, ~1 dpm/100CI! ' fl = 1 907 dpm/100 cm•

I I ~ b F8300223X00014

!: f, ~1 . 829 dpml100 c!ll'

~~ ~X00005 ,,

~ ~ dom/100 a >' "" .D ~ ~ ~ ""~ ' <

Reference Potnt for West Upper Reference Point for East pper W.11 Wall

F8300223XOOO 11 ~~ = 1.589 dpm/100 cm'

II

f830022aX00012 $ ~ - 1.8\!1 d m/100 cm'

D' SMUD!~!lPo~°"~~!~~~"c I NTERIM ONSITE S TORAGE B U ILDING !IOSB)

F8300223X00013

l...Onlracl No.: 4590091426 SMUD ~ = 1,729 dpm/100 cm'

Location: :tanrhn \.rro ~ Task: t:in."11 ~t."ltu r.

Approw:d by. F8300223X00001

Drawing No.: ll'l')IJ l'.-i.u.,1 'i ta tu ,. "-un11•y Description; (c i I r I ... Y•~ · W.t l I Rl•'!>ult ~

p • 1,690 .dpm/100 cm' 0 <i 10 1:r ,~o ;>5 Drown Bv: , ,, . ~ OC'd: J U.·~ · ·4 · Refuenee Point for south

,, -~

?de 1nfret Cote: 10l72016 Appro"°I do\1: UpperWd -- -RH No.; l :2'.......

Page 1 Att. 1 Maps F8300223

Attachment 2

Instrumentation

September 23, 2016

Survey Unit F8300223

Meas.urement . , .. · ·:fype ·.

Beta Static Measurement

Swipe Measurements

Table 2-1. Survey Unit Instrumentation

.: .,

Ludlum Model 2350-1

Ludlum Model 44-116 B Detector

Ludlum Model 2929 Ludlum Model 44-

10-1

Beta - 493 dprn/100 cm2

Alpha - 3 dpm/100 cm2

Beta - 80 dpm/l 00 crn2

· .netector .EfficienCies, • ·. ' . . ·. ~ .. ,

12.9%

36.9% 42.8%

,, ,,

.qalibratiqn' . Due I)ateb . . . '•.. . ., ~ ·.

317899/331973 2/10/17

166716/170380 l l/3/16

• 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

Page 1 Att. 2 Instrumentation F8300223

Static Measurement MDA

Variables Beta Survey Type

331973 Detector Number 170 Background count rate (Gpm)

1 Count Time (min) 0.129 Efficiency

Area of Detector 100 (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:

Static MDA

Page2

Br t E

A

Background Countrate Count Time (min) Efficiency Area of detector (cm2)

493 dpm/100 cm2

Att. 2 Instrumentation F8300223

Att. 3 Investigation

Attachment 3

Investigation

September 23, 2016

Survey Unit F8300223

(none required)

f 8300223

Attachment 4

Data Assessment

September 23, 2016

Survey Unit F8300223

1612 1Wl 1709

Page 1

Histogram for Beta Static Activity Storage Cell C-1

~-----/

I

1758 1007 1&56 1905

Att. 4 Data Assessment

~ !

1 1 I

• • 1 1953 2002 2051

F8300223

i\ctivly I I

Nlr'rt>91otV&kJc.I: 15'

MiiimuM 1.569.15! Maxfn.rn 2.077.~ SD 124.

Skewneu -076,

K1J1tosis o.so! ~Mean 1.868.73!

~"""'" 1.ll9U71 ~tlonnalD.Wb.6'.ln

0Luc8N

\ OMoieBW'it

I

I

I I

I I

I I

I ==.J

1900"

1921!

11160

ld >

"' u <

"""

mo

1680

1620

·1.5 ·1.0

Q-Q Plot for Beta Static Activity Storage Cell C-1 . . I

-0.5

I i

; . i !

no Ml 1.0 1.5

ti• 15 Mean· 1869

Sd•12-4 Slope• 125.il lntefcc-pt • 1809

Conelalion, A • U$5

Theoretical !=luantlles (Standard Normal) f ·~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~--+-~~~~~~--'-~~~~~~~~~~~~-~~~~~~~~'•

Page 2 Att. 4 Data Assessment f 8300223

Smear _Oata_ Calculatio11_Sheet_lOq1G

I IOSB Final Status Survey I I I I

LC1 LC2 LC3 LC4 LC6 LCS (.ICPM (.ldpm ~ate/Time of Count Sample Comments

I

1 F830 021 3 x 00001 SM Cell C-1 51\ 8 ! 08/29/15 14:20

2 F830 022 3 )( 00002 SM CellC·.I so -1 i 08/29/15 14:21

3 F830 022 3 x 00003 SM Cell Cl 45 -13 : 08/29/15 14:17

4 F830 022 3 x 00004 SM Cell C-1 60 22 I 08/29;15 14:23

s F830 022 3 x 00005 SM Cell Cl 49 -4 i 08/29/15 14:10

6 F830 022 3 x 00006 SM Cell C-1 54 8 I 08/29/15 14:26

7 FB30 011 3 )( (}(}()()7 SM Cell Cl 58 18 i 08/29/15 14:19

8 FB30 022 3 x 00008 SM Cell C-1 54 8 i 08/29/15 14:12

9 F830 022 3 x 00009 SM CellC-l 43 -18 i 08/29/15 14:25

10 F830 022 3 x 00010 SM Cell C-1 52 4 i 08/29/15 14:07

11 F830 022 3 x 00011 SM CellC-1 41 ·22 ; 08/29/15 14:09

12 F830 022 3 x 00012 SM CcllC-1 so -1 I 08/29/15 14:13

13 f830 022 3 x 00013 SM Cell C-l 53 6 I 08/29/15 14:16 J.11 FB30 022 3 x 00014 SM Cell C-l 55 11 i 08/29/15 14:24

15 F830 022 3 x 0001.5 SM CellC·l 46 -11 i 08/29/15 14:15 Comments By signnturc below, th" required source check and background checks were salisfoctoril~ pNformcd prior to use of the instrument identified below.

' ! !

! Ludlum 2929 Benchtop Instrument I bkc

clfic.i1::ru:\' bkt: .:cunt

2929 S/N: Hi6716 j rate tirl'I~ MOA ! 0 1 3.0 : <X 0.369

44-10-1S/N:1703$0 cprn min dprn per 11rr!;1

' 7. 71 I

Tech A Sign/ Oat- 2· ~q !'f:: I 50.5 1 80.2 -- Cal Due Date: 11/J/2016 f} 0.428 Tech B Sign/ D~te tJ/A ! cpm min dpm pcri!rt·a

Page 1of1

Page 3 Att. 4 Data Assessment F8300223