ML090890535
| ML090890535 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/18/2008 |
| From: | Ellen Brown Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| Shared Package | |
| ML090830613 | List:
|
| References | |
| DPG 09-097, F8260004 | |
| Download: ML090890535 (40) | |
Text
Rancho Seco Final Status Survey Summary Report September 18, 2008 Turbine Building (-) 15' 6", Condensate Pit Survey Unit F8260004 Prepared By: /
- J-,,, Date:.~
- /// /200)8 FSS Engineer Date:
Reviewed By: C 9 :
- 1 , .
Lead FSS Engineer Approved By: Date: -0 Dismantlement S erintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit:
F8260004, Turbine Building (-) 15' 6", Condensate Pit Survey Unit
Description:
Operating History: The reinforced 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 3077 dpm/1.00 cm 2 and a maximum value of 24,900 dpm/1 00 cm2 . 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 cm 2 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 dpm/100 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/1 00 cm 2 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 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 286 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 10 FSS Summary Report F8260004
Table 1. Survey Unit Design Parameters Survey Design Value Comment Parameter Survey Area: F826 Turbine Building (-) 15' 6",
Condensate Pit Survey Unit: 0004 Structure Surface Class: 1 LTP Table 5-4 SU Area (m2): 286 Evaluator: Erin L. Brown DCGL (dpm/100 cm2): 43000 Gross Activity DCGL Area Factor: 3.6 Class 1 Design DCGLemc 154800 Class 1 2
(dpm/100 cm ):
LBGR (dpm/100 cm 2): 21500 Default = 50% DCGL Design Sigma (dpm/100 cm 2 ): 5990 Type I Error: 0.05 Type II Error: 0.05 Predominant Nuclide: Cs-137 Sample Area (m2): 7 Class 1 Scan Area 2 (M ): 286 Scan Coverage (%): 100% Class 1 Zi, : 1.645 Z1-p : 1.645 Sign P: 0.99865 Calculated Relative Shift: 3.5 Relative Shift Used: 3 Uses 3.0 if Relative Shift is
>3 N-Value: 11 Design N-Value + 20%: 14 NUREG-1575 Table 5-5 Design Min Samples N: 41 Class 1 Grid Spacing L: 2.6 Class 1 Page 3 of 10 FSS Summary Report F8260004
Survey Results:
A total of 46 direct measurements were made in F8260004. 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. ISOCS gamma scan measurements were performed in three locations as shown in Attachment 1. Co-60 or Cs-137 were not identified above the MDC. Scan activity ranged from 1079 to 22066 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 F8260004-CO001 BD 1841 F8260004-CO002BD 2127 F8260004-CO003BD 1675 F8260004-CO004BD 1567 F8260004-CO005BD 1675 F8260004-CO006BD 1769 F8260004-CO007BD 1919 F8260004-CO008BD 2656 F8260004-CO009BD 2329 F8260004-COOIOBD 5032 F8260004-COOI 1 BD 1743 F8260004-CO012BD 1784 F8260004-CO013BD 1603 F8260004-CO014BD 1675 F8260004-CO015BD 1976 F8260004-CO016BD 1592 F8260004-CO017BD 1650 F8260004-CO018BD 1603 F8260004-CO019BD 1784 F8260004-CO02OBD 1587 F8260004-CO021BD 1618 F8260004-CO022BD 1406 F8260004-CO023BD 1509 F8260004-CO024BD 1416 F8260004-CO025BD 1701 F8260004-CO026BD 1338 F8260004-CO027BD 1421 F8260004-CO028BD 1266 F8260004-CO029BD 1494 F8260004-CO03OBD 1489 F8260004-CO031BD 1344 F8260004-CO032BD 1323 F8260004-CO033BD 1302 F8260004-CO034BD 1235 F8260004-CO035BD 1561 Page 4 of 10 FSS Summary Report F8260004
F8260004-CO036BD 1276 F8260004-CO037BD 1307 F8260004-CO038BD 1919 F8260004-CO039BD 2210 F8260004-CO04OBD 1349 F8260004-C0041 BD 1193 F8260004-CO042BD 1484 F8260004-CO043BD 1385 F8260004-CO044BD 1349 F8260004-CO045BD 1271 F8260004-CO046BD 1271 Mean: 1674 Median: 1577 Standard Deviation: 593 Range: 1193 -5032 Page 5 of 10 FSS Summary Report F8260004
Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpm/100 cm 2)
F8260004C0001 SM -0.95 F8260004C0002SM -2.24 F8260004C0003SM -0.95 F8260004C0004SM -3.53 F8260004C0005SM -4.82 F8260004C0006SM -4.82 F8260004C0007SM -3.53 F8260004C0008SM -3,53 F8260004C0009SM -4.82 F8260004C0010SM -4.82 F8260004C001ISM -2.24 F8260004C0012SM -3.53 F8260004C0013SM -2.24 F8260004C0014SM -3.53 F8260004C0015SM -0.95 F8260004C0016SM -4.82 F8260004C0017SM -3.53 F8260004C0018SM -3.53 F8260004C0019SM -2.24 F8260004C0020SM -0.95 F8260004C0021 SM -3.53 F8260004C0022SM -2.24 F8260004C0023SM -2.24 F8260004C0024SM -3.53 F8260004C0025SM -0.95 F8260004C0026SM -4.82 F8260004C0027SM -6.11 F8260004C0028SM -2.24 F8260004C0029SM -3.53 F8260004C0030SM -2.24 F8260004C0031SM -2.24 F8260004C0032SM -2.24 F8260004C0033SM -4.82 F8260004C0034SM -0.95 F8260004C0035SM -4.82 F8260004C0036SM -0.95 F8260004C0037SM -3.53 F8260004C0038SM -0.95 F8260004C0039SM -2.24 F8260004C0040SM -4.82 F8260004C0041 SM -2.24 F8260004C0042SM -3.53 F8260004C0043SM -2.24 F8260004C0044SM -2.24 F8260004C0045SM -0.95 F8260004C0046SM -2.24 Mean: -2.91 Median: -2.24 Page 6 of 10 FSS Summary Report F8260004
Standard Deviation: 1.41 Range: -6.11 to -0.95 Page 7 of 10 FSS Summary Report F8260004
Survey Unit Data Assessment:
The survey design required 46 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 8 of 10 FSS Summary Report F8260004
Table 4. Data Assessment Results Survey Results Parameter Value Comment Material Background Used (dpm/100 cm 2): N/A Ambient Background Used (dpm/100 cm 2): N/A Average Ambient BKG = 0 Actual Direct Measurements (N): 46 2
Median (dpm/100 cm ): 1577 Mean (dpm/100 cm 2 ): 1674 Direct Measurement Standard Deviation 593 2
(dpm/100 cm ):
Total Standard Deviation (dpm/100 cm 2): 593 Based on samples and backgrounds.
Maximum (dpm/100 cm 2 ): 5032 Material Type: N/A Background Subtract Not Applied Sign Test Final N Value: 46 S+ Value: 46 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 9 of 10 FSS Summary Report F8260004
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 43000 dpm/100 cm 2 and none of the removable surface activity measurements exceeded 10% of the DCGL. No investigations were required.
Thedirect 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 F8260004 meets the release criteria of I OCFR20.1402.
Page 10 of 10 FSS Summary Report F8260004
Attachment 1 Maps September 18, 2008 Survey Unit F8260004
(t~
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N Map F8260004-1, Turbine Building Grade and Below Elevations Location of Condensate Pump Pit Area
18.875 ft. 18.875 ft.
F __~~________________
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//
II
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Location of Turbine Building inside Industrial F 3ft. _____j Area
-i Sft.
5.2 ft.
1 ft I 12.3 ft.
K 8.6 ft.
0) 0, 00 00 0.5 1.0 1.5 2.0 t') Distance in Meters CN 17.3 ft.
Map. F8260004-2, Condensate Pump Pit Area Estimate: 286 sq. meters,
0 t'Q to 2.75 ft.- 2.92 ft. 16.125 ft. 292 ft-! 275 ft-: 292 ft1 1& 125 ftý 2_92 ft',2_7.5 ft East Wall 9.9 ft.
Co f
I9 9 ft. - .8.6 ft.
North Wall 0.5 ft.4tL3Lsft.Ift. 99.9ft. ' 3 ~ ft; 9.,*..
9.9 ft.
ItO 00
_8.61ft.__. 4,9-ft ....
C) 4ý- L - 9.6*. ; 3-ft, 9,V.9ft. 1L-31A-L--rn50.5 ft.
South Wall Map F8260004-3, Condensate Pump Pit Wall Dimensions 0.0 0.5 10 1.5 2.0 Distance in Meters
(Di 0l 15.6 ft 15.6 ft 10.6 ft 10.6 ft West Wall 12.3 ft 17.3 ft.
(01 North- Incline 17.3 ft.
C14 Ii 00 ; -f[
N'- South Incline t'W 0.0 0.5 1.0 1.5 2.0 ON Distance in Meters Map F8260004-4, Condensate Pump Pit Wall Dimensions
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at
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10 12 14 16 I
18 South Incline I
20 iKH S
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24 26 i
28 30 0 1 2 3 4 Map F8260004-5, Condensate Pump Pit Distance in Meters Random Start Location
Distance in meters from South Wall 0
t'J c:j~
_ 118BD 1 12m 00 0
Map F8260004-6, Condensate Pump Pit Beta Direct Measurements 0.0 0.5 1.0 1.5 2.0 F8260004C0001 BD to F8260004C0021 BD Distance in Meters 2.6 sq. meter grid
Height in meters 00 36m lm Height in 00 meters C\
lm Ci)
Height in meters 1lm C)1 C0 0.78 m from outh Wall East Wall, 2.6 m grid spacing Map F8260004-7, Condensate Pump Pit Beta Direct Measurements 0.0 0.5 1.0 1.5 2.0 F8260004C0022BD to F8260004C0045BD Distance in Meters 2.6 sa. meter arid
0 00 0.0 0.5 1.0 1.5 2.0 Map F8260004-8, Condensate Pump Pit Dislance in Meters Beta Direct Measurement F8260004C0046BD 2.6 sq. meter grid
Cd) 2BS 3BS 4BS 5BS 8BS 9BS 11BS rn+/-
1lBS, 1OBS
]- - 13BS C) 26S 23BS 417TBS 16BS I5BS 278S 30BS ', 33BS c 36BS 37BS 38BS CO
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-4 5A'RIZ 42BS 41 BS ca C) 53BS 54BS 55BS 56BS 57BS 58BS 59BS 60BS 61BS 62BS 63BS (n
76BS- 75BS 74BS 73BS 72BS 71BS 70BS 69BS 68BS 67BS 66BS .(,.
(n 77BS 788S 79BS 80BS 81BS 82BS 83S 84BS 85BS 86BS 87BS I 99BS 98BS 97BS 96BS 93BS 92BS 91BS 90BS 89BS U) / 1558S 154BS I 1156BS Cd) 101BS 102BS 0) 128BS 127BS Cd) ca 131 BS 133BS 134BS 135BS 107BS 106BS to 104BS 103BS 0 132B5 I. I I 108BS-cc ca 109BS- P- 11OBS 1IBS 112BS 113BS 114BS 140BS 139BS 138BS 137BS (0 N 143BS ca 1448S 145BS 146BS co 120BS- 119BS 118BS 1178S 116BS 115BS It 00 121BS- 1228
-. 123BS 124BS 125BS 126BS 152BS 151BS 1508S 149BS cc C) U) _ _ _
CD 0'
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N Map F8260004-9, Condensate Pump Pit 0.0 0.5 1.0 1.5 2.0 Beta Scan Measurements Distance in Meters F8260004C0001BS to F8260004CO157BS
254BS1 255B13 256BS 257BS 258BS 2598S 2601ýS 261BS 2d2BS 2ý3BS 264BS 265BS 266BS 267BS ý688S 269BS 0 238B1 239B,, 2403S 241BS 242BS 243BS 244,S 245+S 2416S 2,47BS 248BS 249BS 250BS 251BS ,52BS 253BS U-t 222B1 223BS 224BS 225BS 226BS 227BS 2284S 229BS 2,0BS 2031BS 232BS 233BS 234BS 235BS 236BS 237BS 206B9, 207BO 208BS 209BS 21OBS 211BS 212lS 213PS 21f4BS 2ý15BS 216BS 217BS 218BS 219BS P20BS 221BS 1 19 1 13 1 1 1908S4 191B,8 192BS 193BS 194BS 195BS 1964S 19,7BS lq8BS 1!99BS 200BS 201BS 202BS 203BS #048S 205BS
- t -I l , - * - _
East Wall 1581 North Wall (see note) 00 t"Q ON C)
Map F8260004-10, Condensate Pump Pit Beta Scan Measurements F8260004C0158BS to F8260004C0301BS 0.0 0.5 1.0 1.5 2.0 NOTE: 285BS surveyed under 301BS Distance In Meters
0 312BS 165BS 321 BS-: 322BS 323BS 324BS 325BS 330BS 331BS 332BS 333BSJA- 3348S 3187DS3318BS3209 326BS 327BS 328BS 3Z96S C.)
C) o0 0-0 0-5 1.0 1.5 2.0 Map F8260004-11, Condensate Pump Pit Distance in Meters Beta Scan Measurements F8260004CO302BS to F8260004CO334BS
337BS (top of column)
Cr, 0
It' o
C:
Map F8260004-12, Condensate Pump Pit Beta Scan Measurements 0.0 0.5 1.0 1.5 2.0 F8260004CO335BS to F8260004CO337BS Distance in Meters
Map F8260004-13, Condensate Pump Pit Beta Scan Measurements on Metal Plate F8260004MO33BBS to F8280004MO349BS Page 14 of 23 Att. 1 Maps. F8260004
ON 00 Map F8260004-14, Condensate Pump Pit Beta Scan Measurements on Metal Plate (under side)
F8260004MO350BS to F8260004MO361IBS
JS COOO2JS 00001 I Il Li CO001JiS C0002JS OD 0
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0
ý,t 1I t,, 0 r::ý I IC (n
DI0 D010 kýj C.-
C001 0JS 0
arnn 0 0
C)
C) C0033JS C0034JS (corner) (corner)
T] C)
SI1zOJsL) 002JSnn*(j 0 ClI llrIAIJ.
h - ý I, SrSO000 C0 0 28 JjýCOO2JS O3J U, C,,
C0030JSs 0
C) 0 C0 0
CO 0 C-. C,,
U, C', U) 04 0D
- 0) 0 0
SMWOO srLzooo 00 0
0 Map F8260004-15, Condensate Pump Pit fI 0.0 0.5 1.0 1.5 2.0 Juncture Scan Measurements Distance in Meters F8260004CO001JS to F8260004CO034JS
,V CD) 0 C- 0C-O0 C-C/) (n East Wall 00 0'
C: South Wall Map F8260004-16, Condensate Pump Pit Juncture Scan Measurements F8260004CO035JS to F8260004CO036JS, 0.0 0.5 1.0 1.5 2.0 F8260004CO038JS to F8260004CO053JS and Distance in Meters F8260004CO055JS to F8260004CO056JS
00 0
West Wall
ý-I1 00 0.0 0.5 1.0 1.5 2.0 Map F8260004-17, Condensate Pump Pit Distance in Meters Juncture Scan Measurements F8260004C0057JS to F8260004C0058JS
C0059JS C0060JS C0061JS (D
0 l'-h o.* Map F8260004-18, Condensate Pump Pit N Juncture Scan Measurements
____________F8260004C0059JS to F8260004C0061 JS 0o.0 0.5 istar 1.0 1.5 i Metes 2.0 ISOCS Gamma Scan F8260004M0003GS F8260004M0001GS toMeasurements
F8260004 Photos - 1 Page 20 of 23 Att. 1 Maps F8260004
F8260004 Photos - 2 Page 21 of 23 Att. 1 Maps F8260004
F8260004 Photos - 3 Page 22 of 23 Att. 1 Maps F8260004
F8260004 Photos - 4 Page 23 of 23 Att. 1 Maps F8260004
Attachment 2 Instrumentation September 18, 2008 Survey Unit F8260004
Table 2-1. Survey Unit Instrumentation Instrument Detector MDC Static MDC Scan Model; Serial No. Model; Serial No. (dpm/100 cm ) 2 (dpm/100 cm 2 )
M2350; 142507 43-68B; H160781 433 1033 M2350; 203486 43-68B; 190476 433 1033 M2350; 193700 43-68B; 190294 433 1033 M2350; 149789 43-68B; 161415 433 1033 M2350; 142507 43-68B; 160781 433 1033 M2350; 193715 43-68B; 148630 433 1033 M2350; 142507 43-116-1B; 256008 N/A 3258 M2350; 149789 43-116-1B; 256006 N/A 3258 M2350; 193700 43-116-IB; 216072 N/A 3258 M2350; 203486 43-116-1B; 190173 N/A 3258 84 Cs-137 1983920 N/A 70 Cs-60 ISOCS 70 Co-60 Tennelec; 0401171 N/A 5.9 dpm N/A 11.7 dpm P Table 2-2. Investigation Criteria and DCGL Value Parameter (dpmi100 cm 2)
Investigation Criteria - Direct 154800 Investigation Criteria - Scan 154800 DCGLW 43000 DCGLEMC 154800 Page 2 of 2 Att. 2 Instrumentation F8260004
Attachment 3 Investigation September 18, 2008 Survey Unit F8260004 (none required)
Attachment 4 Data Assessment September 18, 2008 Survey Unit F8260004
F8260004 Gross Activity Sample Results Quantile Plot 0 DCGL = 43000 dpm/1 00cm2 6,000 5,000 4,000 (Dj Z,
3,000 2,000 CD 1577 1,000 0
0 20 40 60 80 100 Percentile 00 Direct Measurements (dpm/m0cm2) -median -75th Percentile 50th Percentile
Ce Ujq 0
F8260004 Gross Activity Sample Results Scatter Plot DCGL = 43000 dpml100lcm 6000 CD 5000 0
.Ct E
4000 3453 E 3000 0.
10 0 so 2000 7Zo 0 ~O _.-.0o_
o-- ...
- C6-- - -0 1674
_° O 0 OOOo 00 0000000 4'
1000
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-1000 C)
QOOOOOOQOO OOQOQOOOCOOOOQOQOOQOQOOOOOO*OOO Measurement Locaions bO 1-"-o Gross-Acty'--= Avrg-"+3StDev" - -"-3S1Dev*"-.
CD 00