ML090890539
| ML090890539 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/06/2008 |
| From: | Ellen Brown Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| Shared Package | |
| ML090830613 | List:
|
| References | |
| DPG 09-097, F8260010 | |
| Download: ML090890539 (34) | |
Text
,I Rancho Seco Final Status Survey Summary Report September 6, 2008 Turbine Building -9'6" El. North Condensate Pit Survey Unit F8260010 Prepared By: i kln , Date::
FSS Engineer Reviewed By:'ýý Date: W.0.OO)
Lead FSS Engineer Approved By: ;7 Date: ?
Dismantleme uperintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit:
F8260010, Turbine Building -9'6" El. North 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/100 cm and a maximum value of 24,900 dpm/100 cm 2. 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 cm2 and a maximum value of 3,615 dpm/ 100 cm . Direct measurements on the building exterior showed a mean gross activity level of 1,984 dpm/100 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.
Page 2 of 10 FSS Summary Report F8260010
Survey Area Classification 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 319 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 3 of 10 FSS Summary Report F8260010
Table 1. Survey Unit Design Parameters Survey Design Value Comment Parameter Survey Area: F826 Turbine Building -9'6" El.
North Condensate Pit Survey Unit: 0010 Structure Surface Class: 1 LTP Table 5-4 SU Area (m2): 319 Evaluator: Erin L. Brown DCGL (dpm/100 cmr): 43000 Gross Activity DCGL Area Factor: 3.6 Class I Design DCGLemc 154800 Class I (dpm/100 cm 2):
LBGR (dpm/100 cm 2): 21500 Default = 50% DCGL Design Sigma (dpm/100 cm 2 ): 3130 Type I Error: 0.05 Type II Error: 0.05 Predominant Nuclide: Cs-137 Sample Area (m2): 6.9 Class 1 Scan Area (mi): 319 Scan Coverage (%): 100% Class 1 Zl-* : 1.645 1.645 Sign P: 0.99865 Calculated Relative Shift: 6.8 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: 46 Class I Grid Spacing L: 2.6 Class 1 Page 4 of 10 FSS Summary Report IF8260010
Survey Results:
A total of 49 direct measurements were made in F826001 0. 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 1614 to 34413 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/1OO cm F8260010-COOOIBD 1048 F8260010-CO002BD 1146 F826001 0-CO003BD 1235 F8260010-CO004BD 1157 F8260010-CO005BD 1131 F8260010-CO006BD 1416 F8260010-CO007BD .1172 F8260010-CO008BD 1344 F8260010-Co009BD 1380 F8260010-COOIOBD 1484 F8260010-CO011BD 1551 F8260010-CO012BD 1292 F8260010-CO013BD 1577 F8260010-CO014BD 1458 F826001 0-Co01 5BD 1520 F8260010-CO016BD 1629 F8260010-CO017BD 1473 F8260010-CO018BD 1344 F8260010-CO019BD 1484 F8260010-CO02OBD 1261 F8260010-CO021BD 1535 F8260010-CO022BD 3631 F8260010-C0023BD 1302 F8260010-C0024BD 1665 F8260010-CO025BD 1385 F8260010-CO026BD 1691 F8260010-CO027BD 1426 F8260010-C0028BD 1344 F8260010-CO029BD 1318 F8260010-CO03OBD 1276 F8260010-C0031BD 1644 F8260010-CO032BD 1603 F8260010OCO033BD 1598 F8260010-CO034BD 1816 F8260010-C0035BD 1987 F8260010-CO036BD 1707 Page 5 of 10 FSS Summary Report F8260010
1395 F826001 O-COO37BD F8260010-CO037BD 1895 F826001 O-CO038BD 1297 F8260010-CO039BD 1494 F8260010-C0040BD 1509 F8260010-CO041BD 1307 F826001 O-CO042BD 1183 F8260010-CO043BD 3429 F826001 O-CO044BD 1442 F8260010-C0045BD 1525 F8260010-C0046BD 1401 F826001 O-C0047BD 1338 F8260010-C0048BD 1810 F8260010-C0049BD 131.8 Mean: 1520 Median: 1426 Standard Deviation: 461 Range: 1048 -3631 Rag:10833 Page 6 of 10 FSS Summary Report F8260010
Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpm/100 cm 2)
F8260010CO001SM -3.53 F8260010C0002SM -2.24 F8260010C0003SM -3.53 F8260010C0004SM -3.53 F8260010C0005SM -0.95 F8260010C0006SM -2.24 F8260010C0007SM -0.95 F8260010C0008SM 0.34 F8260010C0009SM -2.24 F8260010CO010SM 0.34 F8260010CO011SM -2.24 F8260010C0012SM -2.24 F8260010C0013SM -0.95 F8260010C0014SM -0.95 F8260010C0015SM -4.82 F8260010C0016SM -4.82 F8260010C0017SM -3.53 F8260010C0018SM -4.82 F8260010C0019SM -2.24 F8260010C0020SM -4.82 F8260010C0021SM -2.24 F8260010C0022SM -6.11 F8260010C0023SM -2.24 F8260010C0024SM -3.53 F8260010C0025SM -4.82 F8260010C0026SM -6.11 F8260010C0027SM -2.24 F8260010C0028SM -3.53 F8260010C0029SM -0.95.
F8260010CO030SM 1.64 F8260010C0031SM -3.53 F8260010C0032SM -0.95 F826001 OC0033SM -4.82 F8260010C0034SM -0.95 F8260010C0035SM -3.53 F8260010C0036SM -2.24 F8260010C0037SM -0.95 F8260010C0038SM -3.53 F8260010C0039SM -4.82 F8260010C0040SM -2.24 F8260010C0041SM -2.24 F8260010C0042SM -0.95 F8260010C0043SM 0.34 F8260010C0044SM -4.82 F8260010C0045SM -3.53 F8260010C0046SM -3.53 F8260010C0047SM -4.82 F8260010C0048SM 0.34 Page 7 of 10 FSS Summary Report F8260010
F8260010C0049SM -2.24 Mean: -2.63 Median: -2.24 Standard Deviation: 1.81 Range: -6.11 to 1.64 Page 8 of 10 FSS Summary Report F8260010
Survey Unit Data Assessment:
The survey design required 49 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.
Table 4. Data Assessment Results Survey Results Parameter Value Comment 2
Material Background Used (dpm/100 cm ): N/A Ambient Background Used (dpm/100 cm 2): N/A Average Ambient BKG = 0 Actual Direct Measurements (N): 49 Median (dpm/100 cm 2 ): 1426 2
Mean (dpm/100 cm ): 1520 Direct Measurement Standard Deviation 461 (dpm/100 cm 2):
Total Standard Deviation (dpm/100 cm 2): 461 Based on samples and backgrounds.
Maximum (dpm/100 cm 2): 3631 Material Type: N/A Background Subtract Not Applied Sign Test Final N Value: 49 S+ Value: 49 Critical Value: 30 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 Does the Survey Unit Pass All Criteria? Yes Page 9 of 10 FSS Summary Report F8260010
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.
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 F8260010 meets the release criteria of I0CFR20.1402.
Page 10 of 10 FSS Summary Report F8260010
Attachment 1 Maps September 6, 2008 Survey Unit F8260010
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Location of Turbine Building inside the Industrial Area 00 S Map F826001 0-1, Location of Turbine Building at Rancho Seco site
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N Map F8260010-2, Turbine Building Grade and Below Elevations Location of North Condensate Pit Area
Map F8260010-3, North Condensate Pit Area Area Estimate: 319 sq. meters 0.0 0.6 1 0 1.5 2.0 Dislaný in Moters Page 4 of 17 Att. I Maps F8260010
0 5.3 ft. 2-92 ft, 2-75 fi2.92ft! 15.6ft- ý292ft.1 East Wall 26 ft.
North Wall 1 W1 (j2n 5.4 ft, 35 ft.
West Wall v
U) fi5iA fL 00 L
k) North_ Wall__2 _
0.0 0.5 1.0 1,5 2.0 Map F8260010-4, North Condensate Pit Area Distance in Meters Wall Dimensions
T--c o. +t-i-l F I F
-f itN l
- -t-v I' - - - P-~~r D -
-. ]j} 12 1 i " 1.bIv ~u bil~u Siti l I* 6...I
- 0. 2 4 6 0 1 4 1 8 2 2 2 6 2 0 3 4 3 8 4 2 4 6 4 0 0 I EKI'VIVV02120 I
Page 6 of 17 Att. 1 Maps F8260010
Distance in meters E2 I from East Wall 0.73 m (D Map F8260010-6, North Condensate Pit Area Z
Beta Direct Measurements F8260010C0001 BD to F8260010C0028BD 2.6 sq. meter grid 3.3 m Distance in meters from west end of survey unit 3D 18BD [19ýB:D 15.3m
- 12.7 m 31D 10.1 m ID] 913D 1013D 7.5 m 2.3 m Page 7 of 17 Att. I Maps F8260010
Map F8260010-7, North Condensate Pit Area Beta Direct Measurements CD F8260010C0029BD to F8260010C0049BD -'
00 0 2.6 sq. meter grid 0.15 m from floor C:.2Z e C 0 0.2 m West Wallt0 o mli C/2 00 0- E E
(-N CI)
C' a) C C') LO 0 Cei to 0 c 2 0.0 :0 15 .
(Include horizontal.and vertical surfaces of penetration in 62BS and 63BS scan surveys) 0J 57BS 58135 59 S 6dBS 61BS 62BS 63BS 64BS 65BS 66BS 0
56BS 55BS, 54ýs 53BS 528S 5185S 5085S 49BS 4885 :47BS 37BS 38BS 398S 4qBS 41B13S 42BS 43BS 44BS 45BS 46BS East Wall 29BS 30BS 31BS 32BS 33BS 34 5B S 36BS 201S 19BS 18BS 17BS 16BS 15BS 148S 13BS 58S 6BS 7BS 8BS 9BS 10BS 11BS 12BS North Wall 1 1//
(Include horizontal ledge surfaces in scan surveys of Grids 60 to 65) 25BS 26B1 27BE 28BS 29BS
-. -j 24BS 238 22B13 21BS --- 20BS 1BS 2B1 3BS! 48S - 5BS West Wall 375BS 374BS 373BS 372BS 371BS 370BS 369BS 368BS 367BS 366BS 365BS 364BS 3 362B1 361BS 360B 359BS 342BS 343BS 344BS 345BS 346BS 347BS 348BS 349BS 350BS 351BS 352BS 353BS 354BS 355BE 356BS 357BS 358BS t-j 341B 340BS 339BS 338BS 337BS 3368S 335BS 334BS 333BS 332BS 331BS 330BS 329BS 328BE 3278s 3268S 325B8 North Wall 2 ON Map F8260010-8, North Condensate Pit Area Beta Scan Measurements 0.0 0.5 1.0 1.5 2.0 F8260006C0001BS to F8260006C0066BS and Distance in Meters F8260028C0325BS to F8260006C0375BS
East Wall 67BS i0 I o 70BS 718S 72BS 73BS~ Map F8260010-9, North Condensate Pit Area Beta Scan Measurements F8260006C0067BS to F8260006C0125BS and 82BS88 ,,8B 9BS 8S 7785 768$ C F8260006C0147BS to F8260006C0324BS 83BS t4B5 55 8B 8B 8 8985 z
- 098BS 97BS 96BS 95BS 94BS 93BS, 92BSL 99BS 100BSj1OlBS1 102BSI 10ý3BS 10485' 10585 10685 107BS 115B5 114BS 113BS 112BS 1098S .- 10885 11685 117BSI 11885 119BSý icR I1081148 122BS 12385 U) 192RS BR 1878$ 188J 12585, Ig* 154B8 1558S '156BS I58 I58I U')
(0 04 I C U) I 165B5 164BS 163BS 2BS 1618 U) 166BS 167BS 168BS CO 00 U) 173BS 172BS 171 BS U)
V MC 174BS 1758S 176BS 177001 17QM0I170M4 I 1Qi Ono 101 Dc BS 12BSh l 2108S 209B5 208BS 207BS 206BS 205BS 204BS 2038S 20285 201B 200BS qleAA5-,..3 -
2118$ 212BS 213BS 214BS 215BS 216BS 217BS 218BS 219S 220BS 221BS 2348S 23385 232BS 231BS 230BS 2298$ 2288S 227S 2268$ 225B 224BS 235BS 23685 2378$ 238BS 239BS 2408S 2418S 242BS 243BS 244B 2458S C, 2498S 2488S 258B$ 257BS 256BS 2558 25485 2538S 252BS 2518S 2508 5, 259BS 2608$ 261BS 262BS 263B8S 2648S 265BS 266BSI 26785 U) 1/4' "1 02 2785 277BS 2768S I275BS 274BS 2738S 272BS 2718S 2708S 0) a)
N
~; 2785 ri 2085281BS 282BS 2838S 28485I 2858S 2868S 287BS 1/4 300BS 29985 298BS 297BS 2968S 295BS 294BS 2938S 2928S I
301BS 3028$ 3038$ 304BS 305BS 3068S 3078S 308BS 309BS 3108S 311BS N U) 0,0 0,5 1.0 1,5 2.0 32485 323BS 322BS 321BSI 3208$I 3198S 318BS 317BS 3168S 3158$ 148 CDP)
Distance in Meters Page 10 of 17 Att. I Maps F8260010
(D 0
--.1 00 Map F8260010-1O, North Condensate Pit Area Beta Scan Measurements F82.60010C0126BS to F8260010C0134BS Juncture Scan Measurement F82600 10CO024JS
Map F8260010-11, North Condensate Pit Area Juncture Scan Measurements F8260010C0001JS to F8260010C0010JS and F826001 0C001 7JS to F826001 0C0023JS 1
C,)
0 0
0 N
0.0 0.5 1.0 1.5 2 .0 Distance in Meters Page 12 of 17 Att. I Maps F8260010
(0 U.)
0 C,)
-~1 C) 0 0) aWl East Wall North Wall 1 N W Nest Wall 0)
It1 55.8 ft.
00 North Wall 2 C')
Map F8260010-12, North Condensate Pit Area 0.0 0.5 1.0 1.5 2.0 Distance in Meters Juncture Scan Measurements F8260010CO011JS to F8260010C0016JS
Map F8260010-13, Condensate Pump Pit Juncture Scan Measurement F8260010C0025JS, Beta Scan Measurements on Metal Plate F8260010OM135BS to F8260010M0140BS Page 14 of 17 Att. 1 Maps F8260010
Map F8260010-14, Condensate Pump Pit Beta Scan Measurements on Metal Plate F8260004MO135BS to F8260004MO146BS Page 15 of 17 Att. 1 Maps F8260010
Photos -1 Page 16 of 17 Att. 1 Maps F8260010
Photos -2 Page 17 of 17 Att. 1 Maps F8260010
Attachment 2 Instrumentation September 6, 2008 Survey Unit F8260010
Table 2-1. Survey Unit Instrumentation Instrument Detector MDC Static MDC Scan 2
Model; Serial No. Model; Serial No. (dpm/100 cm ) (dpm/100 cm 2 )
M2350; 149789 43-68B; 161415 433 1033 M2350; 175834 43-68B; 148634 433 1033 M2350; 193715 43-68B; 148630 433 1033 M2350; 193700 43-116-1B; 216072 N/A 739 M2350; 193715 43-116-1B; 190643 N/A 739 M2350; 175834 43-116-1B; 190642 N/A 739 Tennelec; 0401171 N/A 5.9 dpm x, N/A TheDC__noedreheostconervtiv__1 a 11.7s pm P The MDC's noted are the most conservative for the actual survey performed.
Table 2-2. Investigation Criteria and DCGL Value Parameter Val uec2 (dpm/100 CM )
Investigation Criteria - Direct 154800 Investigation Criteria - Scan 154800 DCGLW 43000 DCGLEMC 154800 Page 2 of 2 Att. 2 Instrumentation F8260010
Attachment 3 Investigation September 6, 2008 Survey Unit F8260010 (none required)
Attachment 4 Data Assessment September 6, 2008 Survey Unit F8260010
F8260010 Gross Activity Sample Results Quantile Plot DCGL = 43000 dpm/1 00cm2 4,000 3,500 CD 3,000 2,500 2I2,000 1,500 1426 1,000 500
~j~
C) 2j 0
0 20 40 60 80 100 Percentile
- Direct Measurements (dpm/100cm2) - median - - - 75th Percentile - -- - 50th Percentile
-TD
CD 0* F826001 0 Gross Activity Sample Results Scatter Plot DCGL = 43000 dpmI100cm 2 4000 3500 -
E 04 3 0 00 - - - - - - - - - - - - - - - - - - - - - - - - - - - ---2904 S2500 a
"30 2000 - 0 0 __ 00 0
.1 - -- - - - -- ,
o -- -D0 0 0 0 0 0 00 00 0 0 0 0 0 0 0 0 0 1000 °0ooo 500 0
Measurement Locations LILrossActy -Average - - "+3StDev" - - "3StDev" 0 0 rs d4 Aeae--"3te ý3e C0
CD PF826001 0 Gross Activity Frequency Plot 0
DCGL = 43000 dpm/1 00cm2 242-*°,,
22 18 20 ~ ~ * ~ :b~
0 -12'-
OO b~o, Bins - Upper End Value (dpm/100cm2)