ML090890536

Final Status Survey Report 09/15/08, Turbine Building (-) 9' 6, South Condensate Pit Area, Survey Unit F8260006

ML090890536
Person / Time
Site:	Rancho Seco
Issue date:	09/15/2008
From:	Sacramento Municipal Utility District (SMUD)
To:	NRC/FSME
Shared Package
ML090830613	List: ML090830313 ML090830314 ML090830316 ML090830318 ML090830319 ML090830320 ML090830321 ML090830322 ML090830323 ML090830324 ML090830541 ML090830542 ML090830543 ML090830544 ML090830545 ML090830546 ML090830547 ML090830548 ML090830573 ML090850549 ML090850550 ML090850551 ML090850552 ML090850553 ML090850554 ML090850555 ML090850556 ML090850557 ML090850558 ML090850559 ML090850560 ML090850561 ML090850562 ML090890534 ML090890535 ML090890536 ML090890537 ML090890539 ML090890584 ML090890585 ML090890586 ML090890587 ML090890588 ML090890727 ML090900729 ML090900730 ML090900731 ML090900732 ML090900733 ML090900770 ... further results
References
DPG 09-097, F8260006
Download: ML090890536 (32)

Text

Rancho Seco Final Status Survey Summary Report September 15, 2008 Turbine Building (-) 9' 6", South Condensate Pit Area Survey Unit F8260006 Prepared By: f. & )to

,-

r-J Date: 9 i//2_XA3 FSS Engineer Reviewed By: 7

• Date: 1t o&t*'0 Lead FSS Engineer Approved By: Date: 7 -07 Dismantlement Sýýperintendent, Radiological

FINAL STATUS SURVEY

SUMMARY

REPORT Survey Unit:

F8260006, Turbine Building (-) 9' 6", South Condensate Pit Area 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/l100 cm 2 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 cm2 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/100 cm 2 and a maximum value of 10,312 dprn/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 310 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 F8260006

Table 1. Survey Unit Design Parameters Survey Design Value Comment Parameter Survey Area: F826 Turbine Building (-) 9' 6",

South Condensate Pit Area Survey Unit: 0006 Structure Surface Class: 1 LTP Table 5-4 SU Area (m2): 310 Evaluator: Erin L. Brown DCGL (dpm/100 cm 2): 43000 Gross Activity DCGL Area Factor: 3.8 Class I Design DCGLemc 163400 Class 1 (dpm/100 cm 2):

LBGR (dpm/100 cm2)" 21500 Default = 50% DCGL Design Sigma (dpm/100 2 cm ): 3130 Type I Error: 0.05 Type II Error: 0.05 Predominant Nuclide: Cs-137 Sample Area (m2): 6.9 Class 1 Scan Area (m2): 310 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: 45 Class I Grid Spacing L: 2.6 Class 1 Page 3 of 10 FSS Summary Report F8260006

Survey Results:

A total of 50 direct measurements were made in F8260006. 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 1460 to 52642 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 F8260006-CO001BD 2983 F8260006-CO002BD 2910 F8260006-CO003BD 3118 F8260006-CO004BD 2765 F8260006-CO005BD 2381 F8260006-CO006BD 2739 F8260006-Co007BD 2339 F8260006-CO008BD 2573 F8260006-CO009BD 2096 F8260006-CO01OBD 2614 F8260006-CO011 BD 2480 F8260006-COOI 2BD 2288 F8260006-CO013BD 2236 F8260006-CO014BD 2246 F8260006-CO01 5BD 2308 F8260006-CO016BD 2231 F8260006-CO01 7BD 1764 F8260006-Co01 8BD 1598 F8260006-CO019BD 1509 F8260006-CO02OBD 1655 F8260006-CO021BD 1712 F8260006-CO022BD 1624 F8260006-CO023BD 1520 F8260006-CO024BD 1779 F8260006-CO025BD 1608 F8260006-CO026BD 2111 F8260006-CO027BD 2381 F8260006-CO028BD 9882 F8260006-CO029BD 3963 F8260006-CO03OBD 1722 F8260006-C0031 BD 1930 F8260006-CO032BD 1945 F8260006-CO033BD 1976 F8260006-CO034BD 1442 F8260006-CO035BD 1375 F8260006-CO036BD 1904 Page 4 of 10 FSS Summary Report F8260006

1302 F8260006-COO37BD F8260006-CO037BD 1302 F8260006-CO038BD 1344 F8260006-CO039BD 1592 F8260006-C0040BD 1509 F8260006-CO041BD 3802 F8260006-CO042BD 1753 F8260006-CO043BD 1478 F8260006-CO044BD 1541 F8260006-C0045BD 1369 F8260006-CO046BD 1447 F8260006-CO047BD 1624 F8260006-CO048BD 1364 F8260006-CO049BD 1598 F8260006-CO05OBD 1784 Mean: 2184 Median: 1844 Standard Deviation: 1268 Rangqe: 1302-9882 Raqe 30-98 Page 5 of 10 FSS Summary Report F8260006

Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpm/100 cm 2)

F8260006C0001 SM 0.34 F8260006C0002SM 0.34 F8260006C0003SM .-0.95 F8260006C0004SM -2.24 F8260006C0005SM -3.53 F8260006C0006SM -4.82 F8260006C0007SM -2.24 F8260006C0008SM 1.64 F8260006C0009SM -4.82 F8260006C0010SM -2.24 F8260006C0011SM 0.34 F8260006C0012SM -0.95 F8260006C0013SM -2.24 F8260006C0014SM 0.34 F8260006C0015SM -4.82 F8260006C0016SM -4.82 F8260006C0017SM -4.82 F8260006C0018SM -3.53 F8260006C0019SM -6.11 F8260006C0020SM 1.64 F8260006C0021SM -0.95 F8260006C0022SM -3.53 F8260006C0023SM 1.64 F8260006CO024SM -4.82 F8260006CO025SM -2.24 F8260006CO026SM -3.53 F8260006CO027SM 0.34 F8260006CO028SM -3.53 F8260006CO029SM -2.24 F8260006CO030SM -4.82 F8260006CO031SM -4.82 F8260006CO032SM -4.82 F8260006CO033SM -3.53 F8260006CO034SM -3.53 F8260006CO035SM -2.24 F8260006CO036SM -2.24 F8260006CO037SM -2.24 F8260006CO038SM -3.53 F8260006CO039SM -2.24 F8260006CO040SM -2.24 F8260006CO041SM -0.95 F8260006CO042SM -3.53 F8260006CO043SM -4.82 F8260006CO044SM 0.34 F8260006CO045SM -3.53 F8260006CO046SM -2.24 F8260006CO047SM -0.95 F8260006CO048SM -4.82 Page 6 of 10 .FSS Summary Report F8260006

F8260006C0049SM -3.53 F8260006C0050SM -6.11 Mean: -2.57 Median: -2.24 Standard Deviation: 2.07 Range: -6.11 to 1.64 Page 7 of 10 FSS Summary Report F8260006

Survey Unit Data Assessment:

The .survey design required 50 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 F8260006

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): 50 Median (dpm/100 cm 2): 1844 Mean (dpm/100 cm 2): 2184 Direct Measurement Standard Deviation 1268 (dpm/100 cm 2):

Total Standard Deviation (dpm/100 cm2): 1268 Based on samples and backgrounds.

Maximum (dpm/100 cm 2): 9882 Material Type: N/A Background Subtract Not Applied Sign Test Final N Value: 50 S+ Value: 50 Critical Value: 31 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 F8260006

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 F8260006 meets the release criteria of IOCFR20.1402.

Page 10 of 10 PFSS Summary Report F8260006

Attachment 1 Maps September 15, 2008 Survey Unit F8260006

0 Uo

-I1I 00 C)

C)

Map F8260006-1, Location of Turbine Building at Rancho Seco site

10 paI Uj~

00 UN 00 CN C)N Map F8260006-2, Turbine Building Grade and Below Elevations Location of South Condensate Pit Area

Map F8260006-3, South Condensate Pit Area Wall Estimate: 118 sq. meters Floor Estimate: 192 sq. meters Total Area Estimate: 310 sq. meters Page 4 of 15 Att. I Maps F8260006

(P 0

=r Map F8260006-4, South Condensate Pit Area Dimensions N 0. 0. 5 1 1 .0 Di8nm..n M et..

I 31.25 ft.

Page 5 of 15 Att. I Maps F8260006

Cý W.

a 2.9ft. 15.6 ft. 2.92 ft 2.75ft:%2.92-ftl 8.6 ft.

East Wall 26 ft.

South Wall 1 4:

a:

7.3 ft. 3.5ft. 5.4ft, West Wall 00 S555ff 0' 55 5 ft South Wall 2 0.0 0.5 1.0 1.5 2.0 Distance in Metem Map F8260006-5, South Condensate Pit Area Wall Dimensions

0 2 3 4 5 6 7 10 11 12 13 1 1s 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 CD -r --*--, - -i-V--- 1 - iM*z--

0 (n _ - . ." 7 I.

4- 1 21i i-i-HF H9 i II I , '.1

• t [!

(-A -4 _ WI iIII~I I i-I!

• q- LH-4 24. -LPH .1-i -Lf IlI.

I -Il ~T-ThVLI~

114 .FA K'1T

"-1

_hI ii LIi Yp *1 I-4 T ffl il

[4

-I

-lo Ii' " !o Irn I

il Wrc

--JIL-L

-p II 1- 4 -

• -I-L -Z---i o-

!-.~ -f-

"-

I--.- 1 -,---- " ",--Aq-----4"--I L---4-4 0I

'~it]~i1 I I I it I I I i*I I i'-*l

-I--

. . . . .- -H-+A-IF4+-I IL=_i It 0 i~iL~

o~ii1-

-'III

'I -!-*

-hi-- 722 ~ifl~

0 I-.j.

~

I

+/-KLiI I

_FJ -H L iI]-I

-' Vi 0!

~ liii!

4---I--4 ' ' , 1 i I tIHIl 0~I~ l4-4 - I- -F--h.

CO

• 1~~' H-. -L

[

-~

F- I I I o III rv,- 1

_

5-. 101 _ I II

~ K -h If Ii 11 .It+/-

hi ii bO I iF' - -4 -4--~--l- I- t-L 4-.--

0T K 4 4-4-4-I-I-4 -i-I

~ --4---+---i-4-i-I.-4--+/--+/---4---4-4-4-4 4-I-f-i- 4--I-f--

-i

• I _-I I'

I I d7n atJi.e Ip I1j~~.ti .1. -I J

-I-

00 Map F8260006-7, South Condensate Pit Area Beta Direct Measurements F8260006C0001BD to F8260006C0033BD 2.5 sq. meter grid E

0 LU Cl, E

0 E

C UC N_ 0.0 0.5 1.0 1.5 2.0 Distance in Meters Page 8 of 15 Att. 1 Maps F8260006

ýcl 0

Distance in meters from SE corner Distance in meters from SE corner Distance in meters from 2.4 m South Wall 1 00 Distance in meters from 15.0 m 12.5m lO

0. m 7.5 m 5.0Omi 2.5 m 0.0Om SW comer Map F8260006-8, South Condensate Pit Area D isaceinMet Beta Direct Measurements F8260006C0034BD to F8260006C0050BD 2.5 sq. meter grid

(Include horizontal and vertical surfaces of penetration in 26BS scan survey)

East Wall 23BS 24BS 25BS 26BS 27BS 28B 29$S 30BS 181 32BS 33BS 0

22BS2: 21BS 201S 19BS 18BS 17BP 168S 15BS 14BS 13BS 12BS 1BS: 2BS 3BS 4BS 58S 68 78S 8BS OBS 1OBS 118S South Wall 1 50BS 51BS 52BS 53BS 54BS 55BS 56BS 57BS rjh 49BS 48BS 47BS 46BS 45BS 44BS 43BS 42BS 34BS 35BS 36BS 37BS 38BS 39BS 40BS 41BS (Include horizontal ledge surfaces in scan surveys of Grids 23 to 28) 68BS 69BS lOBS 711S 72BS 67BS 66BS $51S 641S 63BS 58BS 59BS 6OBS 6BBS 62BS South Wall2 356BS 357BS 358BS 3596BS 360BS 361BS 362BS 363BS 364BS 365BS 366BS 367BS 368BS 3698 370BS 371BS 372B13 3558 354BS 353BS 352BS 351BS 350BS 349BS 348BS 347BS 346BS 345BS 344BS 343BS 341B 374BS 340BS 339B1 322BS 323BS 324BS 325BS 326BS 327BS 32B8 329BS 330BS 331BS 332BS 333BS 334BS 335BE 336B{ 337BS 338B'j I0 ON 0

C) 00 05 10 15 2.0 Map F8260006-9, South Condensate Pit Area Distance in Meters Beta Scan Measurements F8260006C0001 BS to F8260006C0072BS and F8260006C0322BS to F8260006C0372BS

Inlu-0 818 41 80BS 79BS& 78BS I 778S 03 10 74BS 73BS I i I - --

82BS -* 83BS 8483 85BS 86BS 87BS 88BS 89BS 9083 I I I

99893BIS 98BS 97BS: 968$ 95BS BS 1S 00 I I

• I f I I I 1OOBS----- 1018S 102BS 103BS 104BS 5BS 106BS 107 BS 1188BS 1171S 116BS 115BS 1148S 113BS 112BS 111BS 1OBS 109BS Map F8260006-10, South Condensate Pit Area Beta Scan Measurements 119BS-* 120BS .123BS 124BSý 125BS 126BS 127BS F8260006C0073BS to F8260006C0140BS and F8260006C0171 BS to F8260006C0321 BS 135BS 134BS 131B3S 1308S 129BS 1288S 137BS 171BS 1 1738 S 174BS I ý139B3 140BS a

208BS 181Bs 180BS! 179BS 178BS 177BS 138BS C'

MO 209BS 684BS 185BS3 186B3 187BS

• 1 188BS co 210BS 02

! 193BS 192BS 0r)

M2 2118S ' 196BS 197BS

. 207Bs'206BS 205BS 204S8 2038S 202BS 213BS 214BS 215BS 216BS 217BS 218B8 219BS 220BS 221B8 S N 232BS 231BS 230BS 229BS 228BS 2278 226BS 2258S 224BS 233BS 234BS -235BS 236BS 237BS 238BS 239BS 24083 241BS c',

N 2528S 25lE81250S 249B3 248BS 24783 24683 24583 24483 25383 254BS 255BS 256BS 257BS 258BS 259BS 260BS 261BS N02

• fl 272BS 2718S 270BS 269BS 268BSI 267BS 266BS 2658S 264BS

.2738 274BS 275BS 276BS 277BS 2788 28083 281BS 291BS 290BS 289BS 288BS 190BS 287BS 286BS 285BS 284BS S 9 B 29383 Ks.:"'_:'.'.'

2928S 9 B 294BS 295BS 296BSl 297BS 29883 299BS 30083 N . 311BS 3108S 309BS 308BS 307BS I306BS 305BS'1304BS 303BS C14 02 M2 0.0 0.5 1.0 1.5 2.0 02 Di~a- in Met-a 312BS 313BSI 31483BS 1 316BS.1 317S 31883 319BS1 320BS Page l1 of 15 Att. 1 Maps F8260006

00 Map F8260006-1 1, South Condensate Pit Area Juncture Scan Measurements F8260006C0001JS to F8260006C0010JS and F8260006C0017JS to F8260006C0021JS C-C':

N 0.0 0.5 Dis.Ln -

1:0 1.5 2.0 n M.1-Page 12 of 15 Att. 1 Maps F8260006

0 U0 0j East Wall 3outh Wall 1 1~ 01 U-))

West Wall 00 South Wall 2 k)

Map F8260006-12, South Condensate Pit Area 0.0 0.5 1.0 1.5 2.0 Distance in Meters Juncture Scan Measurements F8260006C0011JS to F8260006C0016JS

Map F8260006-13, South Condensate Pit Area Beta Scan Measurements on railing left in area Page 14 of 15 Att. 1 Maps F8260006

Map F8260006-14, South Condensate Pit Area Beta Scan Measurements on metal covering cross over piping F8260006MO 141 BS to F8260006M0154BS and F8260006M0155BS to F8260006M016OBS Page 15 of 15 Att. I Maps F8260006

Attachment 2 Instrumentation September 15, 2008 Survey Unit F8260006

Table 2-1. Survey Unit Instrumentation Instrument Detector MDC Static MDC Scan Model; Serial No. Model; Serial No. (dpm/100 cm2 ) (dpm/100 cm2 )

M2350; 203486 43-68B; 190476 433 1033 M2350; 193700 43-68B; 190294 433 1033 M2350; 149789 43-68B; 161415 433 1033 M2350; 203481 43-68B; 161405 433 1033 M2350; 193715 43-68B; 160703 433 1033 M2350; 193715 43-68B; 148630 433 1033 M2350; 193700 43-116-1B; 216072 N/A 3258 Tennelec; 0401171 N/A 5.9 dpm a, N/A

___ ___

___ ___

___ ___ ___ ___ ___ 11.7 dpmj30 Table 2-2. Investigation Criteria and DCGL Value Parameter pm1lOO cm 2)

Investigation Criteria - Direct 163400 Investigation Criteria - Scan 163400 DCGLw 43000 DCGLEMC 163400 Page 2 of 2 Att. 2 Instrumentation F8260006

Attachment 3 Investigation September 15, 2008 Survey Unit F8260006 (none required)

Attachment 4 Data Assessment September 15, 2008 Survey Unit F8260006

F8260006 Gross Activity Sample Results Quantile Plot t') 2 0 DCGL = 43000 dpm/1 00cm 12,000 10,000 8,000 41_

cj)

I 4-'

6,000 CD, I 4,000 "

2,000 1844 0

0 20 40 60 80 100 ITI Percentile 00 Direct Measurements (dpm/100cm2) - median - - - 75th Percentile - -- - 50th Percentile

0o F8260006 Gross Activity Sample Results Scatter Plot DCGL = 43000 dpm/100cm=

12000 10000 0 E 8000 r

• 0 6000 5988 CL 0.

"O 4000 ooo0 %.0 Z.Q.o_. oo. - -- 0 o__-

0 0

-

2000 000000000 2184 4' 00-00 O 0 0 00000000 U3 I- 100 1011- 0o

>' -1620 00 -2000

>N

-4000 ooo oo ooo oo oo I o......... .. .......... .

0*

C) 0*

Measurement Locations Co FWGross Activity--- Awrag - - "+3StDev" - - "-3StDev '4 0o

-P, F8260006 Gross Activity Frequency Plot 0

ODCGL = 43000 dpm/1 00cm2 30 -~~

28 -.

24

• 168

.014-O20 oBinsV. '4 UperEd

- aue(pm10c2

>

100 O6 c*4 B