ML082620096
| ML082620096 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 06/09/2008 |
| From: | Tallman D Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| References | |
| MPC&D 08-064 | |
| Download: ML082620096 (22) | |
Text
Rancho Seco Final Status Survey Summary Report June 9, 2008 Primary Sample Station Rm 319 uppers Survey Unit F8131782 Prepared By: Dan A. Tallman Date: June 9, 2008 FSS Enginee/
Reviewed By.
Date:
Lead FSS Engineer Approved By:
'7 Date: 7 ?
Dismantlement Superintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit:
F8131782, Primary Sample Station Rm 319 uppers Survey Unit
Description:
Operating History: The Auxiliary Biulding 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/1 00 cm2 and a maximum value of 24,781 dpm/100 cm. Based on the classification procedure (DSIP-0020) and levels of gross activity reported, the upper walls and ceiling of the Primary Sample Station, room 319 of the interior of the auxiliary building were determined to be a Class 2 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 64 m2 were scanned for approximately 48% 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 F8131782
Table 1. Survey Unit Design Parameters Survey Design Value Comment
.Parameter Survey Area:
F813 Survey Unit:
Class:
SU Area (m2):
Evaluator:
DCGL (dpm/100 cm 2):
Area Factor:
Design DCGLemc (dpm/100 cm 2):
LBGR (dpm/100 Cm2):
Design Sigma (dpm/100 cm 2):
Type I Error:
Type II Error:
Predominant Nuclide:
Sample Area (m2):
Scan Area (M2):
Scan Coverage (%):
Zl-. :
Zl-p :
Sign P:
Calculated Relative Shift:
Relative Shift Used:
N-Value:
Design N-Value + 20%:
Design Min Samples N:
Grid Spacing L:
1782 2
132 D.A.Tallman 43000 N/A N/A 21500 3627 0.05 0.05 Cs-137 9.4 64 48%
1.645 1.645 0.99865 5.9 3
11 14 14 3.0 Primary Sample Station Rm 319 uppers Structure Surface LTP Table 5-4 Gross Activity DCGL Class 2 Class 2 Default 50% DCGL Class 2 Class 2 Uses 3.0 if Relative Shift is
>3 NUREG-1575 Table 5-5 Class 2 Class 2 Page 3 of 8 FSS Summary Report F8131782
Survey Results:
A total of 17 direct measurements were made in F8131782. 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 1621 to 5949 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 Activit (dpm/100 cm)
F8131782-CO001 BD F8131782-CO002BD F8131782-CO003BD F8131782-CO004BD F8131782-CO005BD F8131782-CO006BD F8131782-CO007BD F8131782-CO008BD F8131782-CO009BD F8131782-COOIOBD F8131782-CO011 BD F8131782-CO012BD F8131782-CO01 3BD F8131782-CO014BD F8131782-CO015BD F8131782-CO016BD F8131782-CO017BD Mean:
Median:
Standard Deviation:
Range:
1743 1810 1525 1380 1416 1753 1836 1712 1655 1670 1530 1577 1504 1665 1504 1281 1401 1586 1577 162 1281 - 1836 Page 4 of 8 FSS Summary Report F8131782
Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpml100 cm 2)
F8131782C0001 SM F8131782C0002SM F8131782C0003SM F8131782C0004SM F8131782C0005SM F8131782C0006SM F8131782C0007SM F8131782C0008SM F8131782C0009SM F8131782C0010SM F8131782C001 1 SM F8131782C0012SM F8131782C0013SM F8131782C0014SM F8131782C0015SM F8131782C0016SM F8131782C0017SM F8131782C0015SM Mean:
Median:
Standard Deviation:
Range:
-3.53
-2.24
-4.82
-0.95
-3.53
-3.53
-0.95
-4.82
-2.24
-3.53
-3.53 2.93
-3.53
-4.82
-4.82 0.34
-3.53
-3.53
-2.81
-3.53 2.04
-4.82 to 2.93 I
Page 5 of 8 FSS Summary Report F8131782
Survey Unit Data Assessment:
The survey design required 17 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 F8131782
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):
17 Median (dpm/100 cm 2):
1577 Mean (dpm/100 cm2):
1586 Direct Measurement Standard Deviation 162 (dpm/100 cm2):
Total Standard Deviation (dpm/00 cm2):
162 Based on samples and backgrounds.
Maximum (dpm/00 cm2):
1836 Material Type:
N/A Background Subtract Not Applied Sign Test Final N Value:
17 S+ Value:
17 Critical Value:
12 Sufficient Samples Collected:
Yes Maximum Value < DCGL:
Yes Median Value < DCGL:
Yes Mean Value < DCGL:
Yes Maximum Value < DCGLemc:
N/A Class 2 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 F8131782
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 2 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 2 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 F8131782 meets the release criteria of 10CFR20.1402.
Page 8 of 8 FSS Summary Report F8131782 Maps June 9, 2008 Survey Unit F8131782
(~)I CD 24 SQ M -'
CONCRETE Ji\\
R oe 00 LJ
-£....-
/
viizzrz PLAN VIEW ELEV. 50'-6' REFLECTED PLAN VIEW ELEV. 59'-6"+/-
REFLECTED PLAN VIEW ELEV. 50'-0" ELEV LKG WEST AT COL. LINE P ELEVATION LOOKING EAST AT SHIELD WALL 00 00 CAl t\\ATf KI/K I ('nA'lkI!C' l
CCI ITI LLLV*
AT COL. LINE 10.3 SCALE METERS KS SMUD SACRAMENTO MUNICIPAL UTILIlY DISTRICT AUXILIARY BUILDING EL. 40'-0" 319
& 320 CEILING &
UPPER WALLS GENERAL ARRANGEMENT SURFACE AREA ESTIMATE F8131782-M1
'.050 SHEET 1 of 1 RC RAYMOND FI!. F,
, 1Y,,fl I~IL
0
- 4.
=,-
!~/1 T 4
- ///t/.*-"
w:
A
....T 6.
- I,*,U
- l ','
-' -'W
- I I
- !:'I",'. ',i '*t.
I !I *! ':', I.....
I....
T
-4 4
T
.../
T PIA ff--W H HH" iii i
H i i H
H H
H l
, ',H H
II I......
L M,=-'=
T" T
A.
m:OL T*
At gig H...+
o i.,
!ELE~~i*ON *
,LE.NINlO KUfG NOTH oETR*OA CTN*T
- 4ý4
- 4 -4 UTI[_14 DISRI T
F81 7482
-M2K1
-2 TIE X13O0eSET1 f3R AM N 00 00
0 (d~
VIC T u TV--fT V3.1
.1 3"
ELEvv.. 4o*-o AUXILIARY BLDG KEY PLANS PLAN VIEW ELEV. 50'-6' REFLECTED PLAN VIEW ELEV. 59'-6"+/-
00 00 Ix-)
@o SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. 40'-0" ROOM 319 UPPER FLOOR & CEILING PLANS BETA DIRECT/REMOVABLE ACTIVITY MEASUREMENT LOCAT.ONS F8131782-M2 0
1 3
SCALE METERS
0 00 00
,P)
NOTIN I SURVEY i
ii li TUNIT /
ELEVATION LO AT CIL.
i 1
~I i
I I
NOTES DENOTES THAT SURVEY UNIT INR CONTINUES)
AROUND A CORNER.
EL. 50'-6" OKING NORTH
ýNE 9.7 ELEVATION LOOKING EAST AT COL LINE R ELEVATION LOOKING EAST AT SHIELD WALL ELEVATION LOOKING SOUTH ELEVATION LOOKING WEST AT CDL LINE 1 nl03 AT COL. LINE P AT COL. LINE P SCALE METERS SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. 40'-0" ROOM 319
& 320 UPPER WALLS BETA DIRECT/REMOVABLE ACTIVITY MEASUREMENT LOCATIONS F8131 782-M2 SHEET 3 of 3 RC RII F" l.D,,-fl*
RAYMOND FILE: 8 13
0 I ý, M ELEV. 40 0
KEY PLANS tj~
PLAN VIEW ELEV. 50'-6' REFLECTED PLAN VIEW ELEV. 59'-6"+/-
00 00 t'.)
0"-
1 2
(
SCALE METERS
- smu a SACRAMENTO MUNiCIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. 40'-0" ROOM 319 UPPER FLOOR & CEILING PLANS BETA SCAN MEASUREMENT LOCATIONS F81 31 782-M3
0 ELEVATION LOOKING NORTH ELEVATION LOOKING EAST AT COL LINE R AT COL. LINE 9.7 ELEVATION LOOKING EAST AT SHIELD WALL 00 00 N
i.
Li 3] 44 421?
39 43 I. -
DENOTES THAT SURVEY UNIT WR (CONTINUES) AROUND A CORNER.
© i
Cý-' -11 ELEVATION LOOKING SOUTH ELEVATION LOOKING WEST AT COL UNE 10.1 SCALE METERS AT COL. UNE P 0@
SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT AUXILIARY BUILDING EL. 40'-0" ROOM 319
& 320 UPPER WALLS BETA SCAN MEASUREMENT LOCATIONS F8131782-M3 SHEET 2 of 2 RC FILE. 81300 RAYMOND Instrumentation June 9, 2008 Survey Unit F8131782
Table 2-1. Survey Unit Instrumentation Instrument Detector MDC Static MDC Scan Model; Serial No.
Model; Serial No.
(dpmll00 cm 2 )
(dpm/100 cm 2 )
M2350; 203486 43-68B; 190476 433 1033 Tennelec; 0401171 N/A 6 dpm a, 12 dpmf3 N/A Table 2-2. Investigation Criteria and DCGL Value Parameter VleC2 (dpm/100 cm2)
Investigation Criteria - Direct 43000 Investigation Criteria - Scan 43000 DCGLW 43000 DCGLEMC N/A Page 2 of 2 Att. 2 Instrumentation F8131782 Investigation June 9, 2008 Survey Unit F8131782 (none required)
Data Assessment June 9, 2008 Survey Unit F8131782
ao 00 0-0 00 F8131782 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
1677
-t-0 20
-40 60 Percentile 80 100 I
- Direct Measurements (dpm/10Ocm2)
-median
- - 75th Percentile - - - - 50th Percentile I
CD 0
F8131782 Gross Activity Sample Results Scatter Plot DCGL = 43000 dpmll00cm2 C'D
(.j~
00 00 2500 E 2000 U
1500
- ' 1000 V
500 0
-M--
I1 2071 0 0 0.
0 0
0 0
0 0
" 1 1588 W, M M M w a
M f M M s w w 0 w w w M a
w a w M " M = f.1 1101 0 Ca C 0
a a
a a
0000 Measurement Locations I o Gross Activity -
Average -
"+3StDev" -
"-3StDev"1
0D 0P-CjD CjD cT3 F81 31782 Gross Activity Frequency Plot DCGL = 43000 dpm/1 00cm 2 4-L0 0
3 2
1 0 -+
cc (1
0)
C0 I,)
'-Il 00 0o Bins - Upper End Value (dpm/1 00cm2)