ML090890584
| ML090890584 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 07/04/2008 |
| From: | Andersen D Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| Shared Package | |
| ML090830613 | List:
|
| References | |
| DPG 09-097, F8260011 | |
| Download: ML090890584 (32) | |
Text
Rancho Seco Final Status Survey Summary Report July 4, 2008 Turbine Building (-) 7' El., Lube Oil Pit Survey Unit F8260011 Prepared By:
4.
Date:
7-Z4 Y*Oo' FSS Engineer Reviewed By:\\
J Date:k Lead FSS Engineer Approved By:
____7 Date:
Dismantlement 'Vmperintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit:
F826001 1, Turbine Building (-) 7' El., Lube Oil Pit Survey Unit
Description:
Operating History: The reinforiced concrete and steel structure contained the turbine-generator and supporting systems. The building contained five 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 in the condenser pit elevation showed a mean gross activity level of 3,077 dpm/100 cm 2 and a maximum value of 24,900 dpm/1 00cm2. Direct measurements on the grade elevation showed a mean gross activity level of 2,035 dpm/100 cm 2 and a maximum value of 6,980 dpm/100 cm 2. Direct measurements on the mezzanine elevation showed a mean gross activity level of 1,566 dpm/100 cm2 and a maximum value of 2,626 dpm/100 cm 2. Direct measurements on the +40' elevation showed a mean gross activity level of 2,843 dpml100 cm 2 and a maximum value of 3,615 dpm/100 cm 2. Direct measurements on the building exterior showed a mean gross activity level of 1,984 dpm/l 00 cm2 and a maximum value of 10,312 dpm/100 cm 2. Based on the classification procedure (DSIP-0020) and levels, of gross activity reported, the interior of the turbine building was determined to be Class 1, 2, & 3 areas and the exterior was a Class 3.
HSA Events: HSA Report pg. 63.
Survey Unit Design Information:
The Survey Unit Design Parameters are presented in Table I 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 160.35 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 8 FSS Summary Report F8260011
Table 1. Survey Unit Design Parameters Survey Design Value Comment Parameter Survey Area:
F826 Survey Unit:
Class:
SU Area (M2):
Evaluator:
DCGL (dpm/1 00 cm 2):
Area Factor:
Design DCGLemc (dpm/100 cm 2):
LBGR (dpm/100 cm 2):
Design Sigma (dpm/100 cm 2):
Type I Error:
Type II Error:
Predominant Nuclide:
Sample Area (m2):
Scan Area (m2):
Scan Coverage (%):
Zip:
Sign P:
Calculated Relative Shift:
Relative Shift Used:
N-Value:
Design N-Value + 20%:
Design Min Samples N:
Grid Spacing L:
0011 1
160.35 D. Anderson 43,000 3.6 154,800 33,610 3,130 0.05 0.05 Cs-137 6.97 160.35 100%
1.645 1.645 0.99865 3
3 11 14 23 2.6 Turbine Building (-) 7' El.,
Lube Oil Pit Structure Surface LTP Table 5-4 Gross Activity DCGL Class 1 Class 1 Adjusted Class 1 Class 1 Uses 3.0 if Relative Shift is
>3 NUREG-1575 Table 5-5 Class 1 Class 1 Page 3 of 8 FSS Summary Report F8260011
Survey Results:
A total of 24 direct measurements were made in F82600 11. 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 1,331 to 13,858 dpm/100 cm2, 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 F8260011-CO001BD 2,101 F8260011-CO002BD 2,163 F8260011-CO003BD 1,852 F8260011-CO004BD 1,675 F826001 I *C0005BD 1,966 F8260011-CO006BD 2,210 F8260011-Co007BD 1,717 F8260011 -CO008BD 1,468 F8260011-CO009BD 1,841 F8260011-CO01OBD 1,821 F826001 1-CO011 BD 1,380 F8260011-Co012BD 1,473 F8260011-Co013BD 1,406 F8260011-CO014BD 1,375 F8260011-CO015BD 1,520 F8260011-Co016BD 1,463 F8260011-CO017BD 1,349 F8260011-CO018BD 1,727 F8260011-CO019BD 1,468 F8260011-CO02OBD 2,713 F826001 1 -C0021 BD 1,541 F8260011-CO022BD 1,473 F8260011-CO023BD 1,312 F8260011-CO024BD 1,141 Mean:
1,673 Median:
1,530 Standard Deviation:
360 Range:
1,141 - 2,713 Page 4 of 8 FSS Summary Report F8260011
Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpm/100 cm 2)
F826001 1 C0001 SM F826001 1 C0002SM F826001 1 C0003SM F826001 I C0004SM F826001 I COOO5SM F8260011CO006SM F8260011CO007SM F826001 1 C0008SM F826001 1 C0009SM F8260011CO010SM F8260011CO011SM F8260011CO012SM F8260011Co013SM F8260011CO014SM F8260011CO015SM F8260011C0016SM F8260011CO017SM F8260011C0018SM F8260011Co019SM F8260011 C0020SM F8260011C0021SM F8260011 C0022SM F826001 1 C0023SM F826001 1 C0024SM Mean:
Median:
Standard Deviation:
Range:
1.64
-3.53 1.64
-3.53
-0.95
-4.82
-0.95
-3.53
-4.82 0.34
-4.82
-2.24
-2.24
-3.53
-0.95
-3.53
-3.53
-3.53
-4.82
-4.82
-3.53 2.93
-0.95
-2.24
-2.35
-3.53 2.25
-4.82 to 2.93 Page 5 of 8 FSS Summary Report F8260011
Survey Unit Data Assessment:
The survey design required 24 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 F8260011
Table 4. Data Assessment Results Survey Results Parameter Value Comment Material Background Used (dpm/100 cm2):
N/A Ambient Background Used (dpm/100 cm2):
N/A Average Ambient BKG = 0 Actual Direct Measurements (N):
24 Median (dpm/100 cm'):
1,530 Mean (dpm/100 cm2):
1,673 Direct Measurement Standard Deviation 360 (dpm/100 cm2):
Total Standard Deviation (dpm/100 cm 2):
360 Based on samples and backgrounds.
Maximum (dpm/100 cm 2 ):
2,713 Material Type:
N/A Background Subtract Not Applied Sign Test Final N Value:
24 S+ Value:
24 Critical Value:
16 Sufficient Samples Collected:
Yes Maximum Value < DCGL:
Yes Median Value < DCGL:
Yes Mean Value < DCGL:
Yes Maximum Value < DCGLemc:
Yes Class 1 Total Standard Deviation <= Sigma:
Yes Pass the Sign Test?
Yes Reject the Null Hypothesis?
Yes I Does the Survey Unit Pass All Criteria?
Yes I Page 7 of 8 FSS Summary Report F8260011
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 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. No potential areas of elevated activity were detected. 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 43,000 dpm/100 cm2 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 F826001 I meets the release criteria of IOCFR20.1402.
Page 8 of 8 FSS Summary Report F8260011 Maps July 4, 2008 Survey Unit F8260011
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Location of Turbine Building inside the Industrial Area 00
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L Map F8260011-1, Turbine Building Lube Oil Pit Area Location of Turbine Building at Rancho Seco site
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Location of Lube Oil Pit at (-) 7' El.
North 0PPiImn 2
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in Metatm Map F8260011-3, Turbine Building (-) 7' El.
Lube Oil Pit Area Floor Area Estimate: 81.75 sq. meters Page 4 of 17 Att. I Maps F8260011
0 North Column Support North Wall Looking Looking: Looking West South !
East 0
0 Looking :Looking; South West Looking South North Column Support Detail South Wall South Column Support East Wall South Column Support Detail 00 t'J 0'
West Wall 0
0.5 1.0 1.5 2.0 Distance in Meters Map F8260011-4, Turbine Building (-) 7' El.
Lube Oil Pit Area Walls Area Estimate: 78.6 sq. meters
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I 4812 16 20 24 28 Page 6 of 17 Att. 1 Maps F8260011
Distance E E in meters C6 from east edge of trough Ca1.m 3.7 m Below Grade Trough N
0 0.5 1.0 1.5 2.0 Distance in Meters Map F8260011-6, Turbine Building (-) 7' El.
Lube Oil Pit Floor Beta Direct Measurements F8260011 C0001BD to F8260011 C0006BD 2.6 m by 2.6 m grid spacing Page 7 of 17 Att. I Maps F8260011
0.7 m from 9.9 m 7.3 m 4.7 m 2.1 m from SouthWall N
0 0.5 1.0 1.5 2.0 Distance in Meters Map F8260011-7, Turbine Building (-) 7' El.
Lube Oil Pit Area Beta Direct Measurements F8260011C0007BD to F8260011CO01OBD 2.6 m by 2.6 m grid spacing Page 8 of 17 Att. I Maps F8260011
00 C/)
2T
@0 Distance in meters above floor LII 0.25 m C o (Do
- Distance in meters above floor 0.25 m 3
C 3
003
!R 0
(n~
3 corner corner Distance in meters above floorII
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Eo02I 2c 0.25 m 0
0.5 1.0 1.5 2.0 Distance in Meters Map F8260011-8, Turbine Building (-) 7' El.
Lube Oil Pit Walls Beta Direct Measurements F8260011C0011BD to F8260011C0024BD 2.6 m by 2.6 m grid spacing
H 1BS 2BS 3BS 4BS Ca 1OBS 9BS 8BS 7BS 6BS.
1IBS 12BS 13BS 14BS 15 S North Pumnp Platform 20BS 19BS 18 S 17BS 16 S 21BS 22BS 23BS 24BS 25BS 26BS 30BS 29BS 28BS 27BS H H
31BS 32BS 33BS 34BS 35BS 40BS 39BS 38BS 37BS 36BS North Wall of Trench Trench ASouth Waill ofTrench 41 BS 42BS 43BS 44BS 45BS 50 BS 49BS 48S-47BS 46 3S South
Pump, Platform 51BS 5285 53 S 54BS 55 S 60BS 59BS 58BS 57B~S 56BS 61B8 H
N 0.5 1.0 1.5 2.0 Distance in Moters H
Map F8260011-9, Turbine Building (-) 7' El.
Lube Oil Pit Floor Beta Scan Measurements F8260011 CO001BS to F8260011 C0061 BS F8260011 Page 10 of 17 Att. I Maps
0 76BS R
77BS 123BS CO 75BS 73BS 72BS IBS 70BS 69E 0
63BS 64BS 65BS [
BS 67BS 68 csj 121 1S 120BS 119BS 118BS 117BS CI C
24 0
Ca 1112 S 11 385 114BS
%513S 116BS North Wall Looking: Looking: Looking:.
West ý South East 109BS
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.1L South South Wall Wooktr West :,
South 107BS 106BS I0513S 104BS 103BS
>108B 99BS i
81S I 97 BS 102BS I01BS 1 1 96BS 11OBS 95BS 94BS 93BS D)0BSII lOIBS 192BS 7 8 8 S
7 9 8 S
8 0 1 8 B
8 E 8S 8 8 B S 8 9 B S 9 0B S
9 2 B S 78S89S I80Si 1BS 82BS 838S I;4BS 85BS 8B 9S 98 East Wall Looking Looking Looking B
South East North 148BS 149BS 150BS 151BS 152BS 153BS 154BS 155BS 156BS 157BS 158BS
~I4 3BS (ceiling of below gra de trench) 147BS 146BS 145BS 144BS BS 141BS 140BS 139BS 138BS 137BS 136BS 124BS 125BS 126BS 127BS 129BS 130BS 131BS 132BS 133BS 134BS 135BS ITI 00 It" West Wall 0
0.5 1.0 1.5 2.0 Distance in Meters Map F8260011-10, Turbine Building (-) 7' El.
Lube Oil Pit Walls Beta Scan Measurements F8260011 C0062BS to F8260011 C0158BS
0 0.5 1.0 1.5 2.0 Dislence in Meters Map F8260011-11, Turbine Building (-) 7' El.
Lube Oil Pit Area Beta Scan Measurements F8260011 CO148BS to F8260011CO170BS Page 12 of 17 Att. 1 Maps F8260011
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0 (Floor Drain:
previously grouted)
SPL00O0 0
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Pump C.
Platform 0
Cn CO005JS C~Dl CDN srumL00 O
South Pump o
Platform 0
CO011Js G
(Floor Drain:
previously grouted)
NI 0
0.5 1.0 1.5 2.0 Distance in Meters Map F8260011-12, Turbine Building (-) 7' El.
Lube Oil PitArea: Floor, Trench & Trough Juncture Scan Measurements F8260011C0001JS to F8260011 C0022JS Page 13 of 17 Att. 1 Maps F8260011
C0026JS
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North Wall Looking Looking: Looking:
West South !
East LooKing South LOOKingf West:
Looking South ITI 00 0'
C>..
C0038JS 0
0.5 1.0 1.5 2.0 Distance in Meters Map F8260011-13, Turbine Building (-) 7' El.
Lube Oil Pit Walls Juncture Scan Measurements F826001 1 C0023JS to F826001 1CO040JS
South End of Lube Oil Pit NOrtm t-na oT Lune uii H'it Photos-1 Page 15 of 17 Att. 1 Maps F8260011
West Wall of Lube Oil Pit East Wall of Lube Photos-2 Page 16 of 17 Att. I Maps F8260011
Horizontal Surface above West Wall of Lube Oil Pit Below Grade Trench that extends outside Turbine Bldg.
Photos-3 Page 17 of 17 Att. I Maps F8260011 Instrumentation July 4, 2008 Survey Unit F8260011
Table 2-1. Survey Unit Instrumentation Instrument Detector MDC Static MDC Scan Model; Serial No.
Model; Serial No.
(dpm/100 cm 2 )
(dpm/100 cm2 )
M2350; 203486 43-68B; 190476 433 1,033 M2350; 193700 43-68B; 190294 433 1,033 M2350; 203481 43-68B; 161405 433 1,033 M2350; 175834 43-68B; 148634 433 1,033 M2350; 193700 43-116-1B; 216072 491 739 Tennelec; 0401171 N/A 5.88 dpm a, N/A 11.71 dpmr Table 2-2. Investigation Criteria and DCGL Value Parameter (dpm/100 cm 2)
Investigation Criteria - Direct 154,800 Investigation Criteria - Scan 154,800 DCGLw 43,000 DCGLEMC 154,800 Page 2 of 2 Att. 2 Instrumentation F8260011 Investigation July 4, 2008 Survey Unit F8260011 (none required)
Data Assessment July 4, 2008 Survey Unit F8260011
0 CA, 00 t'J F8260011 Gross Activity Sample Results Quantile Plot DCGL = 43000 dpm/1 00cm2 ZI 3,000 -
2,500 -
2,000 -
1,500 -
1,000 -
1530 500 0
0 20 40 60
.80 100 Percentile Direct Measurements (dpm/100cm2) -
median -
- - 75th Percentile....
50th Percentile
-D F8260011 Gross Activity Sample Results Scatter Plot A
DCGL 43000 dpmi00cm=2 3000 2753
- 2500 E
12000 o
A E
1673 D
I500 0
0 0
0 0
0 joo 0
CO 00000 0000 00000 00000000 a
a 0
0 0
0 0
0 0
a a
a a
a 0
0 a
a 0
0 a
a a
a Measurement Locations 00~Aerg tl-o Gross Actlvlty Average -
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- "3 Dev';
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CD CD F826001 1 Gross Activity Frequency Plot DCGL = 43000 dpm/1 00cm2 10 9
a)
C 0
8 7
6 5
4 3
2 1
0 (0
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-(,
00 Bins - Upper End Value (dpm/1 00cm2)