ML082620157

From kanterella
Jump to navigation Jump to search
Final Status Survey Semmary Report, June 17, 2008, AB-20 Corridor Column R-T, Survey Unit F8130161
ML082620157
Person / Time
Site: Rancho Seco
Issue date: 07/30/2008
From: Tallman D
Sacramento Municipal Utility District (SMUD)
To:
NRC/FSME
References
MPC&D 08-064 F8130161
Download: ML082620157 (28)
v • d • e


Text

Rancho Seco Final Status Survey Summary Report June 17, 2008 AB -20' corridor column R-T Survey Unit F8130161 Prepared By: Dan A. Tallman A Date: June 17, 2008 FSS Engineer Reviewed By:'.ý_*9 Date:.

8 Lead FSS Engineer Approved By:

Date:__ __

Dismantlement Superintendent, Radiological

FINAL STATUS SURVEY

SUMMARY

REPORT Survey Unit:

F8130161, AB -20' corridor column R-T 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. The direct measurements on the -20' elevation showed a mean gross activity level of 247,831 dpm/100 cm2 and a maximum value of 10,080,000 dpm/1 00 cm 2. Based on the classification procedure (DSIP-0020) and levels of gross activity reported, the main east - west corridor between columns R and T in the -20' elevation of the interior of the auxiliary building was determined to be a Class 1 area.

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 determined using a random-start, fixed grid pattern and 310.1 m2 were scanned for 100% 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 9 FSS Summary Report F8130161

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

Survey Unit:

Class:

SU Area (m2):

Evaluator:

DCGL (dpm/100 cm'):

Area Factor:

Design DCGLemc (dpm/100 cm 2):

LBGR (dpm/100 cm'):

Design Sigma (dpm/100 cm 2)"

Type I Error:

Type II Error:

Predominant Nuclide:

Sample Area (m2):

Scan Area (M2):

Scan Coverage (%):

Sign P:

Calculated Relative Shift:

Relative Shift Used:

N-Value:

Design N-Value + 20%:

Design.Min Samples N:

Grid Spacing L:

F813 0161 1

310.1 D.A.Tallman 43000 3.58 153867 21500 12035 0.05 0.05 Cs-137 6.89 310.1 100%

1.645 1.645 0.955435 1.7 1.7 AB -20' corridor column R-T Structure Surface LTP Table 5-4 Gross Activity DCGL Class I Class I Default = 50% DCGL Class 1 Class 1 Uses 3.0 if Relative Shift is

.>3 NUREG-1575 Table 5-5 Class 1 Class 1 14 17 45 2.6 Page 3 of 9 FSS Summary Report F8130161

Survey Results:

A total of 47 direct measurements were made in F8130161. The results including mean, median, standard deviation and range are shown in Table 2. All direct measurements were less than the DCGL. No FSS measurements indicated areas of elevated activity.

Scan activity ranged from 1482 to 54498 dpm/100 cm2, based on a surveyor efficiency of 0.5 and no background subtracted. ISOCS scan activity on the walls and ceiling ranged from 1116 to 12,300 dpm/100cm 2 for Cs-137 with all scans MDA for Co-60. 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.

Page 4 of 9 FSS Summary Report F8130161

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

+

F8130161-C0001BD F8130161-CO002BD F8130161-CO003BD F8130161 -Co004BD F8130161 -CO005BD F8130161-CO006BD F8130161 -CO007BD F8130161 -CO008BD F8130161 -Co009BD F8130161-CO0IOBD F8130161 -Coo I BD F8130161--Co012BD F8130161-C0013BD F8130161--Co014BD F8130161--Co015BD F8130161-CO016BD F8130161-CO017BD F8130161-COOlBBD F8130161-CO019BD F8130161-CO02OBD F8130161 -C0021 BD F8130161 -CO022BD F8130161 -CO023BD F81 30161 -CO024BD F8130161-CO025BD F8130161-CO026BD F8130161-CO027BD F8130161 -CO028BD F8130161 -CO029BD F8130161-CO03OBD F8130161-CO031BD F8130161 -CO032BD F8130161-CO033BD F8130161 -CO034BD FB130161 -CO035BD F8130161 -CO036BD F8130161-CO037BD F8130161-CO038BD F8130161 -CO039BD F8130161 -CO04OBD F8130161-CO041BD F8130161 -CO042BD F8130161 -CO043BD F8130161-CO044BD F8130161 -CO045BD F8130161-CO046BD F8130161-CO047BD Mean:

Median:

Standard Deviation:

Ranqce:

1717 1712 1696 1826

.1790 1504 1624 1592 1535 3035 3916 2443 2511 2832 5239 1899 1914 2163 2116 1515 1369 1639 1411 1608 1629 1530 1286 1442 1572 1390 1660 1499 1421 1489 1375 1390 1733 1644 1520 1541 1582 1432 1598 1561 1468 1577 1551 1819 1592 705 1286-5239 Page 5 of 9 FSS Summary Report, F8130161

Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpmll00 cm 2)"

F8130161 COON SM F8130161 C0002SM F8130161 C0003SM F8130161 C0004SM F8130161COOO5SM F8130161 C0006SM F8130161 C0007SM F8130161 C0008SM F8130161 C0009SM F8130161CO010SM F8130161CO011SM F8130161CO012SM F8130161CO013SM F8130161CO014SM F8130161CO015SM F8130161 Co016SM F8130161 CO017SM F8130161 COW08SM F8130161C0019SM F8130161 C0020SM F8130161CO02ISM F8130161 C0022SM F8130161CO023SM F8130161 C0024SM F8130161 C0025SM F8130161 C0026SM F8130161 C0027SM F8130161 C0028SM F8130161 C0029SM F8130161 C0030SM F8130161CO031SM F8130161C0032SM F8I 30161 CO033SM F8130161CO034SM F8130161 C0035SM F8130161 C0036SM F8130161 C0037SM F8130161 C0038SM F8130161CO039SM F8130161 C0040SM F8130161CO041SM F8130161 CO042SM F8130161C0043SM F8130161 C0044SM F8130161C0045SM F8130161 C0046SM F8130161 C0047SM Mean:

Median:

Standard Deviation:

Ranqe:

-0.95

-3.53

-2.24

-0.95 0.34

-2.24

-2.24

-0.95

-3.53 0.34 2.93 2.93 2.93 1.64

-0.95 5.51 17.13 1.64

-2.24 17.13

-4.82 5.51

-3.53 15.84 2.93

-2.24

-3.53

-3.53

-3.53

-2.24 4.22 0.34 1.64 8.09

-0.95

-2.24 19.72 4.22 11.97 0.34 24.88 1.64

.13.26 0.34 15.84 1.64 13.26 3.23 0.34 7.3

-4.82 to 24.88 Page 6 of 9 FSS Summary Report F8130161

Survey Unit Data Assessment:

The survey design required 47 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 7 of 9 FSS Summary Report F8130161

Table 4. Data Assessment Results Survey Results Parameter Value Comment Material Background Used (dpm/100 cm2):

N/A Ambient Background Used (dpmlO00 cm'):

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

47:

Median (dpm/100 cm2):

1592 Mean (dpm/1OO cm2):

1819 Direct Measurement Standard Deviation 705 (dpmr/100 cm 2)"

Total Standard Deviation (dpm/100 cm2):

705 Based on samples and background§.

Maximum (dpm/100 cm2):

5239 Material Type:

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

47 S+ Value:

47 Critical Value:

29 Sufficient Samples Collected:

Yes Maximum Value < DCGL:

Yes Median Value < DCGL:

Yes Mean Value < DCGL:

Yes Maximum Value < DCGLemc:

Yes Class I Total Standard Deviation <= Sigma:

Yes Pass the Sign Test?

Yes Reject the Null Hypothesis?

Yes Does the Survey Unit Pass All Criteria?

Yes Page 8 of 9 FSS Summary Report F8130161

Survey Unit Investigations and Results:

No investigations were required based on the results of the FSS performed within this survey unit.

During routine surveillance surveys utilizing the 44-10 Nal detector, discovery was made in grids 24/25, 26/27, 32/33, & 34/35. The results of this discovery are detailed in attachment 3. The EMC unity rule was not exceeded as shown in to Table 3.-1.

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 and the EMC criterion has been met), the ALARA criterion has been met.

Changes in Initial Survey,Unit Assumptions:

The survey unit was designed as a Class 1 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. Potential areas of elevated activity were detected and evaluated as shown in Attachment 3. Therefore the EMC criterion was met.

==

Conclusion:==

The FSS of this survey unit was properly designed as a Class 1 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 cm2 and none of the removable surface activity measurements exceeded 10% of the DCGL. The required investigations were performed.

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 F8130161 meets the release criteria of 10CFR20.1402.

Page 9 of 9 FSS Summary Report F8130161 Maps June 17, 2008 Survey Unit F8130161

1!12~XP 0

Looli'nt West LookiJng NoOtt

.cp KEY PLAN as 41 00 Sc 0.-

ey Rm. 1.

71;A i zz s-00 u

T11 00 0,

SFPo General Surface Area Estimates Ceilng w/ pipe chase-Walls-Floor-Total -

310.1 m2 77.1 m2 181.3'm2 51.7 m2 Scale Feet 6" = 1'-0" Scale Meters 0

1 2345 o*SMUn SACRAMErNTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. -20 ROOM 15 BETWEEN COLS.

0R9 SURFACE AREA ESTIMATE F81301 61 -Mi 19T99 SFILE 81300.02e SHT 1 OF 1 T C HILL FILE 81300.02e SHT 1 OF 1

00

=

T T

}.

.~i 7-z T**,:

,11

-111 11 11 4

1

,,+4.

+,.,.-.,1,,,,.

,.11+,,,,.,.+4-4-""-"

'1......

T N"

15

?

ooam W

T

'Ea T.1 AX I*L BULD ING EL. -20 1 5

~

Z,-:. V,....

T,

}:*',:',~~~~~~

.~

! Sc

  • lte S

IUD BEWEENCOL.

BETA/DIRECT LOOSE SURFACE RANDOM START o

4 SACRAMENTO MUNICIPAL F81 3.01 61 -M2 1:

3UTIlLITY DISTRICT FILE 81300 02e SlIT 1 OF 1 T CHILL

GO 0

NI v

a'-

Reflected Ceiling T T -T E::::ý T -

a U,

=Hi E:[**i Hatch Cover Opening Sides Hatch Cover Sides I0 0

Scale Feet 32" = 1'-0" Floor Scale Meters 0

1

  • 2 3
  • Smu SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. -20 ROOM 15 BETWEEN COLS. "R" & "T" BETA/DIRECT LOOSE SURFACE MEASUREMENT LOCATIONS F8130161-M2 FILE 81300.02a SHT 2 OF 3 T C HILL FIlE 81300.02e Sf-1T20F3 T CHILL

i:i-e~x~

0 T

.i Looking North u)

C.+-

Doi.

.io Scale Feet 32'" = 1,-0" Scale Meters G

1 2

3 iq c..

fa, Wa)

Cu cuCl Looking-North.,

I'll 00 oN osmu*

SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. -20 ROOM 15 BETWEEN COLS. "R" & "T" BETA/DIRECT LOOSE SURFACE MEASUREMENT LOCATIONS F81 301 61 -M2 cur '4 flI=2 T C HILL

_______________________________________________________Fl-_

81300 02a

O0 0

Reflected Ceiling O'1 00 W

ON Scale Feet 1.=: 1,-0" Scale Meters 0

1 2

Field Of View 56 n?

  • -SuSACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. -20 ROOM 15 BETWEEN COLS. "R" GAMMA SCAN MEASUREMENT LOCATIONS F8130151 -M3

0C KeyPlan Looking North

.......... W a G"

C,,

~-I1 00 ON Wall "B" Looking South Scale Feet 32= 1'-0 Scale Meters 0

1 2

3 Field Of View. 12.56 rm

  • SMUu SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. -20 ROOM 15 BETWEEN COLS.. "R" & "T" GAMMA SCAN MEASUREMENT LOCATIONS F81 30151 -M3 FILE 81300.02a SHT201`4 T C HILL FILE 81300.02e SI-1T20F4 TCHILL

i1li2fXp 00 0

Oi 00 Pipe Chase 025 025 033 04 01

.~

! r;:-.'-'."::. *:':i i*:*:.':--..1/*...

. ",:-.:., i>."" -." ";- -':

~GD Gi Scale Feet 1" -

Scale'Meters 0

1 2

3 GDGD~G~. GD GD* G~GD GD@I ThJGD1GDI~1GDJGEDISDS GD)

GDHD1 1'-

Gý GD (iGDIG1ýiDGDi GD GD GD) GD GDi 4

-.7-n-...

S-.-

Floor

  • mn SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. -20 ROOM 15 BETWEEN COLS.

" R" & "T" BETA SCAN MEASUREMENT LOCATIONS F81301 61--M3 FILE 81300.02e SIT 3 OF4 T C HILL

12.Eixp (D

0 Key Plan Lookingq West iI 1776 1:175 Hatch Cover Opening Sides Hatch Cover Sides Looking. East 00 uj Scale Feet 32-" 1= 0 Scale Meters 0

1 2

3 mul SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. -20 ROOM 15 BETWEEN COLS. "R" & "T" BETA SCAN MEASUREMENT LOCATIONS F81 30161 -M3 FILE 81300.02e SHT4OF4 T CHILL

111iXiý 0u

.0 S,

1/96XP Loon W eso L.W!in Nort L

PIP9 Chase lFront L~oolhg East a -

Retlected Bofttow Pipe Chase WITH THE EXCEPTION OF THOSE IDENTIFIED, JUNCTURES WILL BE EVALUATED USING GAMMA SCPAN DATA Hatch Cover Hatch Cover

.O~enq Sides.

_Sie.

I0 0

wN Floor Scale Feet 116w = 1,-0" 012345 SNU SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. -20 ROOM BETWEEN COLS. "R" & "T"I JUNCTURE BETA SCANS F81 30161 -M4 15 T C HILl j ______________________

T__C______

CD PENETRATIONS MANAGED FROM 813036 LooIkinQ East (l~)

  • S 03W Ot
  • o ai:

PENETRATIONS MANAGED FROlM 813022 S

5050 JO 00 w5 0

LooliJna soutt-Fkoo Scale Feet Scale Meters 0 1 2 3 4 5

  • smuil SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. -20 ROOM 15 BETWEEN COLS.

"R" & "T" PENETRATIONS F81 30161 -M5 FILE 81300.02e SHT 1 OF 1 T C HILL Instrumentation June 17, 2008 Survey Unit F8130161

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

Model; Serial No.

(dpmll00 cm2 )

(dpm/100 cm 2 )

M2350; 180733 43-98B; 148638 3 5 0 A 630 A M2350; 175834 43-68B; 190482 M2350; 203486 43-68B; 190476 M2350; 193700 43-68B; 190294 433 B 1033 B M2350; 149789 43-68B; 161397 M2350; 142509 43-68B; 160699 M2350; 180738 43-68/5B; 148942 M2350; 180738 43-116-1B; 216073 796 B 3258 B M2350; 175834 43-116-1B; 190642 796c 3258c M2350; 203486 43-116-1B; 190173 491D 739D M2350; 203482 44-10; 211672 NA 16756 Tennelec; 0401171 N/A 6 dpm (x, 12 dpmj3 N/A A Penetration - 2" - metal B Structure - surface - concrete c Penetration - 4" to 14" - Concrete D Juncture - concrete Instrument Detector MDC Model; Serial No.

Model; Serial No.

(dpm/100 cm2 )

ISOCS 1983920 1030 (Co6s)

________________________________1420 (Csl137)

' 3920_2m concrete geometry 12.5 m2 FOV Table 2-2. Investigation Criteria and DCGL Value Parameter (dpml100 cm 2)

Investigation Criteria - Direct 153867 Investigation Criteria - Scan' 153867 DCGLw 43000 DCGLEMC 153867 Scan Investigation Level for routine 44-10 surveillance scan set at 20,000 cpm (- 60%

DCGLEMC 0.75 mi2 )

Value (dPml1oo cm?)

Instrument Parameter To detect a I m hot spot at the EMC Criterion within the detector field of view Investigation Criteria -

63,300 dpmr100 cm2 Cs-137 ISOCS Concrete Scan 1 21,275 dpm/100 cm 2 Co-60 3920_2mconcrete geometry 12.5 M 2 FOV Page 2 of 2 Att. 2 Instrumentation F8130161 Investigation June 17, 2008 Survey Unit F8130161

Table 3-1 Survey Unit Investigation Investigation Investigation DCGLemc Gfd' Investigation Initial Value Result Elevated Area DCGLemc Result Unity Level (cpm)

(cpm)

(cpm)

Area (m2)

Factor (dpm/lOOcm2)

Fraction C24/25GS 20000 32000 4000 0.33**

41.48 1,783,640

]

155,255 0.086 C26/27GS 20000 82000 12000 0.01 1294.1 55,646,300 465,766 0.008 C26/27GS 20000 35000 f

8000 0.78**

J. 18.70 804,100 310,511 0.384 C32/33GS 20000 52000

[

4000 0.50**

28.10 1,208,300 155,255 0.127 C32/33GS 20000 49000 4000 0.50**

28.10 1,208,300 155,255 1

0.127 C34/35GS 20000 29000 4000 0.26**

51.86 2,229,980 155,255 1

0.069 C24/25GS N/A N/A 1379 0.33" 41.48 1,783,640 j

10,116 0.047 2 C26/27GS N/A N/A 2488 0.78**

18.70 804,100 1

18,252 0.020 2 C32/33GS N/A N/A

[

1470 0.50**

28.10 1,208,300 10,784 0.014 2 C32/33GS N/A N/A 1507 0.50**

28.10 1,208,300 11,055 0.004 2 C34/35GS N/A N/A 1511 0.26"*

51.86 2,229,980 11,085 0.015_

Juncture G25 N/A N/A 2014 0.1" 1 131.6 5,658,800 45,812 3 0.008 2 Juncture G26 N/A N/A 1624 0.1*

131.6 5,658,800 36,941 '

0.006 2 Juncture G33 N/A N/A 2175 0.1*

131.6 5,658,800 49,475 3 0.008 2 Juncture G34 N/A N/A 976 0.1*

131.6 5,658,800 22,201 3 0.004 2 Juncture G41 N/A N/A 552 0.1*

131.6 5,658,800 12,556 3 0.002 2 Comments:

  • Elevated juncture area estimated at 2" by one meter.
    • Elevated area conservatively estimated at the-surface area of the remediation foot print 1 Discovery made during routine surveillance with 44-10. Insufficient survey documentation available to distinguish exact FSS grid identification.

FSS grids corresponding to surveillance location are as indicated (including the adjacent juncture).

2 Post remediation verification survey included beta scan survey measurements of grid and accompanying juncture area. (EMC Unity Sum = 0.170) 3 Juncture remediation resulted in a geometry most accurately conforming to thatof the Cs1 37 surface scan selected in the DQA.

Survey Unit Remainder DCGL =

SU Mean =

43,000 1821 0.042 EMC Unity Sum 0.809 Page 2 of 2 Att. 3 Investigation F8130161 Data Assessment June 17, 2008 Survey Unit F8130161

0 Ci2 00 F81 30161 Gross Activity Sample Results Quantile Plot DCGL = 43000 dpm/1 00cm2 I

3 6,000 5,000 4,000 3,000 2,000 1,000 0

1692 0

20 40 60 80 100 Percentile Direct Measurements (dpml100cm2) rmedlan -

- -75th Percentile 50th Percentile

0 0

CD a

CD 00 C

F8130161 Gross Activity Sample Results Scatter Plot DCGL = 43000 dpmil00cm1 6000 5000 E 4000 3000

0. 2000 1000 0

-1000 4

00 O

0".

00 00 0 000 O0 0000 0

00000 0000000000 m

m m

m m

m m

  • 000000000*

m 393E

-297 OMOOOOODoDOOOOooooooooooooaoooooocoooo0ooooooo Ctow a""Vi u

P MAW0ment onE Measurement Locations o

Gross Actity -

Average

"+3StDev a

a "-3StDev"'

0 c,,

El 00 F8130161 Gross Activity Frequency Plot DCGL = 43000 dpm/1 00cm2 I-.

U..

LL I

45 42 39 36 33 30 27 24 21 18 15 12 9

6 3

0 C'%J Bins - Upper End Value (dpm/1 00cm2)

Retrieved from "https://kanterella.com/w/index.php?title=ML082620157&oldid=5325701"