ML082620098

Final Status Survey Summary Report, June 2, 2008, AB +40 Room 321, Upper Walls/Ceiling Room 320, Survey Unit F8131792

ML082620098
Person / Time
Site:	Rancho Seco
Issue date:	06/02/2008
From:	Tallman D Sacramento Municipal Utility District (SMUD)
To:	NRC/FSME
References
MPC&D 08-064
Download: ML082620098 (22)

Text

Rancho Seco Final Status Survey Summary Report June 2, 2008 AB +40' Room 321, Upper walls/Ceiling Room 320 Survey Unit F8131792 Prepared By: Dan A. Tallman Date: June 2, 2008 Z

FSS*

e!*

Reviewed By:

Date:Z*?__I_

Lead V6S Engineer Approved By:

Date:

7 L".-C )

Dismantlement uperintendent, Radiological

FINAL STATUS SURVEY

SUMMARY

REPORT Survey Unit:

F8131792, AB +40' Room 321, Upper walls/Ceiling Room 320 Survey Unit

Description:

Operating History: The Auxiliary Building is a reinforced concrete structure that contained the RadWaste processing and supporting systems. The building contained six main elevations. Residual radioactive material was known to be present on all levels of the interior of the building. Operating records and the HSA document several events with the potential for a release of radioactivity inside this structure..

Site Characterization: Direct measurements were made of each of the interior elevation surfaces as well as the exterior surfaces of the structure. These measurements confirmed the presence of plant-derived radionuclides. Direct measurements on the +40' elevation showed a mean gross activity level of 3,288 dpm/100 cm 2 and a maximum value of 24,781 dpm/100 cm. Based on the classification procedure (DSIP-0020) and levels of gross activity reported, room 321 and the upper walls and ceiling of room 320 within the interior of the auxiliary building were determined to be Class 3 areas.

HSA Events: HSA Report pg. 63.

Survey Unit Design Information:

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. Direct measurement locations were randomly determined and 58.75 m2 were scanned for approximately 22%

coverage. Samples of removable contamination were collected at each direct measurement location. The instrumentation used for the survey along with the MDC values are listed in Tables 2-1 and 2-2 in Attachment 2.

Page 2 of 8 FSS Summary Report F8131792

Table 1. Survey Unit Design Parameters Survey Design Value Comment Parameter Survey Area:

F813 Survey Unit:

Class:

SU Area (m):

Evaluator:

DCGL (dpm/100 cm 2):

Area Factor:

Design DCGLemc (dpm/100 cm 2):

LBGR (dpm/I100 cm 2):

Design Sigma (dpm/100 cm 2):

Type I Error:

Type II Error:

Predominant Nuclide:

Sample Area (m2):

Scan Area (m 2):

Scan Coverage (%):

Zl-, :

ZI-p :

Sign P:

Calculated Relative Shift:

Relative Shift Used:

N-Value:

Design N-Value + 20%:

Design Min Samples N:

Grid Spacing L:

1792 3

273 D.A.Tallman 43000 N/A N/A 21500 227 0.05 0.05 Cs-137 N/A 58.75 22%

1.645 1.645 0.99865 94.7 3

11 14 14 N/A AB +40' Room 321, Upper walls/Ceiling Room 320 Structure Surface LTP Table 5-4 Gross Activity DCGL Class 3 Class 3 Default = 50% DCGL C8130179 Class 3 Class 3 Uses 3.0 if Relative Shift is

>3 NUREG-1575 Table 5-5 Class 3 Class 3 Page 3 of 8 FSS Summary Report F8131792

Survey Results:

A total of 14 direct measurements were made in F8131792. The results including mean, median, standard deviation and range are shown in Table 2. All direct measurements were less than the DCGL. None of the scan measurements indicated areas of elevated' activity. Scan activity ranged from 2528 to 5627 dpm/100 cm 2, based on a surveyor efficiency of 0.5 and no background subtracted. Samples for removable surface activity were all less than 10% of the DCGL as shown in Table 3. Removable surface activity samples were counted for alpha activity and none was detected at the MDC shown in Table 2-1 of Attachment 2.

Table 2. Direct Measurement Results Measurement ID Gross Activity (dpm/100 cm )

F8131792-CO001BD F8131792-CO002BD F8131792-CO003BD F8131792-CO004BD F8131792-COOO5BD F8131792-CO006BD F8131792-CO007BD F8131792-CO008BD F8131792-CO009BD F8131792-CO01OBD F8131792-CO01 I BD F8131792-CO01 2BD F8131792-CO013BD F8131792-CO014BD Mean:

Median:

Standard Deviation:

Range:

1520 1489 1691 1354 1473 1660 1639 1634 1577 1743 1722 1686 1675 1707 1612 1650 114 1354-1743 Page 4 of 8 FSS Summary Report F8131792

Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpm/100 cm 2)

F8131792C0001SM F8131792C0002SM F8131792C0003SM F8131792C0004SM F8131792C0005SM F8131792C0006SM F8131792C0007SM F8131792CO008SM F8131792C0009SM F8131792C0010SM F8131792C0011SM F8131792C0012SM F8131792C0013SM F8131792C0014SM Mean:

Median:

Standard Deviation:

Range:

2.93 0.34

-3.53

-3.53

-2.24

-2.24 4.22

-4.82

-4.82

-2.24

-2.24

-0.95 6.8

-4.82

-1.22

-2.24 3.59

-4.82 to 6.8 Page 5 of 8 FSS Summary Report F8131792

Survey Unit Data Assessment:

The survey design required 14 direct measurements for the Sign Test. 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. The sample standard deviation was less than the design standard deviation so no additional samples were required.

Page 6 of 8 FSS Summary Report F8131792

Table 4. Data Assessment Results Survey Results Parameter Value Comment Material Background Used (dpm/100 cm 2):

N/A Ambient Background Used (dpm/100 cm2):

N/A Average Ambient BKG = 0 Actual Direct Measurements (N):

14 Median (dpm/l'00 cm 2):

1650 Mean (dpm/100 cm 2):

1612 Direct Measurement Standard Deviation 114 (dpmrl100 cm 2):

Total Standard Deviation (dpm/IOO cm2):

114 Based on samples and backgrounds.

Maximum (dpm/100 cm 2):

1743 Material Type:

N/A Background Subtract Not Applied Sign Test Final N Value:

14 S+ Value:

14 Critical Value:

10 Sufficient Samples Collected:

Yes Maximum Value < DCGL:

Yes Median Value < DCGL:

Yes Mean Value < DCGL:

Yes Maximum Value < DCGLemc:

N/A Class 3 Total Standard Deviation <= Sigma:

Yes Pass the Sign Test?

Yes Reject the Null Hypothesis?

Yes Does the Survey Unit Pass All Criteria?

Yes Page 7 of 8 FSS Summary Report F8131792

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 (i.e. the survey unit average activity 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 structure 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.

==

Conclusion:==

The FSS of this survey unit was properly designed as a Class 3 survey based on Table 5-4 of the LTP. The required number of direct measurements was made and the scan coverage met the requirement of Table 5-6 of the LTP. No direct measurements exceeded the DCGL of 43000 dpm/100 cm 2 and none of the removable surface activity measurements exceeded 10% of the DCGL. No investigations were required.

The direct 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 F8131792 meets the release criteria of 10CFR20.1402.

Page 8 of 8 FSS Summary Report F8131792 Maps June 2, 2008 Survey Unit F8131792

7.-

k N)

S

/

r4 1 SO M CONCRETE EL. 60l-0" (2)

(9.7' C0 I1

/

/

/'7 7

/

71 /I 1H ft 22 SO M CONCRETE

/9.7*

rY/Y 2A4i 44 SOki PLAN VIEW PLASTER &

ELEV. 40-0"

)

LIGIHT-FIXTURE INOT I

\\

/SUR')

IZ.N El-VAfIONl CKG 'NORTH Rkl 321 AT CGL LINE 9.2 7./1' 4

/

7,

//

. I.

EL. 50'-0O EL. 40- f7 ELEV LKG EAST LIM4 321 AT COL LIýE.P 7)

SCALE METERS 19 SO M CONCRETE

/-

Z-7 1PN I F - 11 LA LŽ...-*-~

SURV7tT'*-"'

I

'4AA 7

/

/

/

7 7

7-

/

/

i

/

/

/

/

7

\\

REFLECTED PLAN VIEW(,'pN ELEV.

-5'0. ~

.2I I* *

.=

.I L

/A

/NOT IX"

• SURVEY UNIT 7

/

v, EL. 60"-O" Y

37 50 l

CONCRETE CONCRETE EL. 50 -0" ELý 40'-0' JTH 2O16 SO 7

CONCRETE RU 321 AT COL INE N CONCRETE

/* I

\\NOT IN"

/

-\\SURVEY/

\\ UNITI,

~

~t.E L 501-0.

EL. 46'-

6%,"

"T*-l OKING NORTH ELEVATION LKG WEST L LINP P.7 RIM 320 EASTi OF COL. LINE N ELEVATION LKG SOI RU 321 ATi COL LINE 9.

t 1///./_/,

/ _

/

/

/

L 00

-1O ELEVATION LO 46 SO M CONCRETE S1MIT E

RU 320 AT CO

• o.>

0*

SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. 40'-0" ROOM 320 & 321 FLOOR, CEILING & WALLS GENERAL ARRANGEMENT SURFACE AREA ESTIMATE I

F8131792-M1 F

II:

05a SHEET 1 of I RC RAYMOND

//

77/

7

/

/

I/

II 7

7

.I7 I 1/

/

i REFLECTED PLAN VIEW FtIrv P19-Ir"+

FILE: ell-30,00.

0 Z "

7 4-3 LEV*,IONSCALE-N

.H

~

HH --......

r*. :.

HH HH H H*

I

+/--

METE-I-.I+H-.-t+ff-4-t 4H.H.ih-"-' '_++

\\

?805 7~A 4+---H~ft--

IIf-4~-

-H-H-

+-H-i--'+1--

ý H

-I 9-H

+H-H-WH+-H-4H-i-HiH-H+

-I-I-I-I-H-1-- 1+11-iH-1-'H-H:ý+

-i++

+

iz-H:

-Hi4i j H-l 9#-1H1-~I~

-H-IlH-

-H-Hi-H4-f-ýi~

A D1 07

-A--_

========

=.

INI?

H Hf

+ -

.c--H H---+H"

'--~.___-4H-_

I4K_

+1--

HH--ifH ELEVATION - KG N:TH ELEV L EAS w:

-7o R E

+/-

/

3U,,i0L-,

-T.O j:

/

_ H~i-4

• 4 H

H HH

'HH':-

I--

+*UII~~---H-

+-I-I-I-+H-I-H

,

J;',*;:,:;!:

H

$"" H-I--I, f 1-f--Hi-H.'H-H-HH H-f BD80 6D23 I,

H I

',',-',-i t

+"-H--.-...-:

RANDOM MEASUREMENT LOCATION EK:I I-Hill-L H

H

-H-H--I-I-

+.

.H.IUTILA4i-TY1 -T-1

-I-HI-

-17 944m4

-H4 +

-1 FIIJC4

-ZJRE I

~ELEVATION Ld-KIG ORT

__WES AUXILIT EAR UIDNKG 'ELST'O AT R

32 321 FLOORE CEILING W

-RANDOM ESUREENT1 LOCATION SACRAE4TOMLHIIPA~

81 3 7'UNITA

__D14

___-BDIO0.~iSHE f~3R AMN 00

-o 4:

0 IIl I AUXLIARY GLDG KEY PLANS PLAN VIEW ELEV. 4(0'-0" REFLECTED PLAN VIEW ELEV. 50'-0" REFLECTED PLAN VIEW ELEV. 59'-6"+/-

0l 00 NOTE.

1. -

DENOTES THAT SURVEY UNIT WRAPS (CONTINUES) AROUND A CORNER.

0 1

2 3

SCALE METERS SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. 40'-0" ROOM 320 & 321 FLOOR, CEILING & WALLS BETA DIRECT/REMOVABLE ACTIVITY MEASUREMENT LOCATIONS F81 31 792-M2 1 13000.5o, SHEET 2 of 3 RC RAYM(

CD

(-4r 00 w4 ELEVATION LKG NORTH ELEV LKG EAST ELEVATION LKG SOUTH RM 321 AT COL UNE 9.2 RM,321 AT COL LINE P RM 321 AT COL LINE 9.7 ELEV LKG NORTH ELEV LKG WEST RM 320 AT COL LINE 9.7 RM 320 EAST OF COL LINE N ELEV LKG WEST RM 321 AT COL LINE N NOTES*.

" DENOTES THAT SURVEY UNIT WRAPS (CONTINUES) AROUND A CORNER.

I SCALE METERS

• 0su SACRAMENT0 MUIPA UTILITY DISTRIC AUXILIARY BUILDING EL. 40'-0" ROOM 320 & 321

FLOOR, CEILING & WALLS BETA DIRECT/REMOVABLE ACTIVITY MEASUREMENT LOCATIONS F81 31 792-M2 TiLE: 813000.050 SHEET 3 of -'

RC RAYMOND

vi

~T.

(p)

ON 0

PLAN VIEW ELEV, 40"-0" I; I "AUXILIARY BLDG KEY PLANS K>'N

-p 92~-

~'

"-I

/

/

Q 7'---

7Z/§$/* 7 4,Z 7 /

.,L 7 Z 7 44/

FVH H

/

S\\

/

/ \\

/

ee.

N ix dyE D

I!

III

~

NOT IN IEY IT REFLECTED PLAN VIEW ELEV. 50'-0" REFLECTED PLAN VIEW ELEV. 59'-6"+/-

'-t' 00 w) 1- -

DENOTES THAT SURVEY UNIT WRAPS (CONTINUES) AROUND A CORNER.

SCALE METERS SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. 40'-0" ROOM 320 & 321 FLOOR.

CEILING & WALLS BETA SCAN MEASUREMENT LOCATIONS F8151792-M3

=

&o SHEEFT i of 2 RC RAYM.(

-11I I OIN f I

813000 (150 SHEET 1 of RC PAYIMONC

0D 0

NOT IN SURVEY UNIT EL. 43'-0"

-EL. 40'-0" ELEVATION LKG NORTH RM 321 AT COL UNE 9.2 ELEV LKG EAST RM 321 AT COL LINE P ELEVATION LKG SOUTH RM 321 AT CCL LINE 9.7 00 ELEV LKG NORTH RM 320 AT COL LNE 9.7 ELEV LKG WEST RM 320 EAST OF COL LINE N ELEV LKG WEST RM 321 AT COL LINE N (C

DENOTES THAT SURVEY UNIT WRAPS COFNTINUES) AROUND A CORNER.

AUXILIARY BUILDING EL. 40'-0" ROOM 320 & 321 FLOOR, CEILING & WALLS BETA SCAN MEASUREMENT LOCATIONS F81 31 792-M3 0

1 2

3 SCALE METERS Instrumentation June 2, 2008 Survey Unit F8131792

Table 2-1. Survey Unit Instrumentation Instrument Detector MDC Static MDC Scan Model; Serial No.

Model; Serial No.

(dpm/100 cm2 )

(dpm/100 cm 2 )

M2350; 189089 43-68B; 161406 433 1033 M2350; 203481 43-68B; 161405 433 1033 M2350; 142509 43-68B; 160696 433 1033 M2350; 142499 43-37; 148502 198 616 Tennelec; 0401171 N/A 6 dpm (x,

-12 dpm3 N/A Table 2-2. Investigation Criteria and DCGL Value Parameter Val ue cm2)

(dpm/100 c2 Investigation Criteria - Direct 21500 Investigation Criteria - Scan 43000 DCGLw 43000 DCGLEMC N/A Page 2 of 2 Att. 2 Instrumentation F8131792 Investigation June 2, 2008 Survey Unit F8131792 (none required)

Data Assessment June 2, 2008 Survey Unit F8131792

0 CD2 En~

00 F8131792 Gross Activity Sample Results Quantile Plot DCGL = 43000 dpm/1 00cm2 I

4-2,000 -

1,800 -

1,600 -

1,400 -

1,200 -

1,000 -

800 -

600 -

400-200-0 1650 t-0 20 40 60 Percentile 80 100 tI

• Direct Measurements (dpmn/l00cm2)

-median

- - 75th Percentile -

- 50th Percentile I

CD F8131792 Gross Activity Sample Results Scatter Plot DCGL = 43000 dpmllOOcmr ITI 00 w) 2500 E2000-1500-I500 0

-mw 1953 0

0 0

0 0

o 0

V

)

I I

1 V-I -

a 0

00 a

0 0

a 0

0 0

0 0

U U

00 U

U Measurement Locations 1612 11271 I o Gross Activity -

Average -

"+3StDev" -

-3StDev 'I

0 (n~

Cd)

F8131792 Gross Activity Frequency Plot DCGL = 43000 dpm/1 00cm 2 5-U-

.o 4-3-

2-1 -

0-0 a)

L()

00 Bins - Upper End Value (dptTV1 00cm2)