ML090900770

Final Status Survey Report for October 29, 2008, Tank Farm Condensate Storage Tank Pad, Survey Unit F8100041

ML090900770
Person / Time
Site:	Rancho Seco
Issue date:	10/29/2008
From:	Tallman D 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
Download: ML090900770 (30)

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Rancho Seco Final Status Survey Summary Report October 29, 2008 Tank Farm Condensate Storage Tank Pad Survey Unit F8100041 Prepared By: Dan A. Tallman_______________

Date: October 29, 2008 FSS Engi eer Reviewed By. Date:- tW4 1O Lead FSS Engineer Approved By:___ _ _ Date: ?- -Dismantlement Superintendent, Radiological FINAL STATUS SURVEY

SUMMARY

REPORT Survey Unit: F8100041, Tank Farm Condensate Storage Tank Pad Survey Unit

Description:

Operating History: The area consists of the concrete pad that supported the Condensate Storage Tank (CST), used to store radioactive liquids. Included in this survey unit are several smaller concrete pads that provided foundation to various pumps and piping associated with the tankage in the tank farm. Operating records and the HSA document several events with the potential for a release of radioactivity associated with this survey area. The HSA documerited the storage of radioactive material within the area that may have had the potential to contaminate the area.Several locations within the perimeter of the designated pads required remediation.

Site Characterization:

Soil samples surrounding the survey unit were collected and analyzed for the presence of plant-derived radionuclides.

Cs-137 was the primary nuclide of plant origin detected with a mean activity level of 379 pCi/g and a maximum value of 1,040 pCi/g. Based on the classification procedure (DSIP-0020) and levels of Cs-137 reported, the area was determined to be a Class 1 area.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 195.1 m 2 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 9 FSS Summary Report F8100041 Table 1. Survey Unit Design Parameters Survey Design Value Comment Parameter Survey Area: F810 Survey Unit: Class: SU Area (m2): Evaluator:

DCGL (dpm/100 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 (m 2): Scan Coverage (%): Sign P: Calculated Relative Shift: Relative Shift Used: N-Value: Design N-Value + 20%: Design Min Samples N: Grid Spacing L: 0041 1 195.1 D.A.Tallman 43000 3.56 152901 21500 7614 0.05 0.05 Cs-137 6.96 195.1 100%1.645 1.645 0.99379 2.8 2.8 12 15 28 2.6 Tank Farm Condensate Storage Tank Pad Structure Surface LTP Table 5-4 Gross Activity DCGL Class I Class 1 Default = 50% DCGL Class I Class I Uses 3.0 if Relative Shift is>3 NUREG-1575 Table 5-5 Class 1 Class 1 Page 3 of 9 FSS Summary Report F8100041 Survey Results: A total of 38 direct measurements were made in F8100041.

The results including mean, median, standard deviation and range are shown in Table 2. All direct measurements were less than the DCGL. Two of the scan measurements indicated areas of elevated activity.

Scan activity ranged from 895 to 71920 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.Page 4 of 9 FSS Summary Report F8100041 Table 2. Direct Measurement Results Measurement ID Gross Activity (dpm/100 cm+F8100041-CO001BD F8100041 -CO002BD F8100041-CO003BD F8100041-CO004BD F8100041-CO005BD F8100041-CO006BD F8100041 -CO007BD F8100041-CO008BD F8100041 -CO009BD F8100041-COOIOBD F8100041-Co011BD F8100041 -Co01 2BD F8100041-Cool 3BD F8100041-CO014BD F8100041-CO015BD F8100041-Co016BD F8100041-Co017BD F8100041 -Co01 8BD F8100041-CO019BD F8100041 -CO02OBD F8100041-CO021BD F8100041-CO022BD F8100041-CO023BD F8100041 -CO024BD F8100041-CO025BD F8100041-CO026BD F8100041-CO027BD F8100041-CO028BD F8100041-CO029BD F8100041-CO03OBD F8100041-C0031BD F8100041-CO032BD F8100041-CO033BD F8100041 -CO034BD F8100041 -CO035BD F8100041-CO036BD F8100041-CO037BD F8100041-CO038BD Mean: Median: Standard Deviation:

Ranqe: 2905 2588 2588.2801 2189*2459 2474 2505 2552 2920 2640 2952 2547 2220 2677 2454 2454 2547 2469 3092 2132 2671 2620 2474 2640 2355 2474 2957 2723 2822 3118 2677 2879 2635 2386 2474 2635 2428 2609 2588 232 2132-3118 Page 5 of 9 FSS Summary Report F8100041 Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpm/100 cm 2)F8100041 C0001 SM -3.53 F8100041C0002SM 4.22 F8100041C0003SM

-3.53 F8100041 C0004SM -2.24 F8100041COOO5SM

-2.24 F8100041 C0006SM -2.24 F8100041 C0007SM -2.24 F8100041C0008SM

-2.24 F8100041 CO009SM -3.53 F8100041C0010SM

-2.24 F8100041CO01ISM

-3.53 F8100041CO0O12SM

-2.24 F8100041CO013SM

-3.53 F8100041CO014SM

-3.53 F8100041COO15SM

-3.53 F8100041COO16SM

-3.53 F8100041CO017SM 2.93 F8100041COO18SM

-2.24 F8100041CO019SM

-4.82 F8100041C0020SM

-0.95 F8100041CO021SM

-3.53 F8100041C0022SM 0.34 F8100041 C0023SM -2.24 F8100041 C0024SM -4.82 F8100041 C0025SM -3.53 F8100041 C0026SM -3.53 F8100041C0027SM

-3.53 F8100041 C0028SM -2.24 F8100041 C0029SM -3.53 F8100041 C0030SM -6.11 F8100041C0031SM 2.93 F8100041 C0032SM -4.82 F8100041C0033SM 4.22 F8100041C0034SM

-3.53 F8100041C0035SM

-3.53 F8100041 C0036SM -4.82 F8100041 C0037SM 0.34 F8100041C0038SM 6.8 Mean: -2.1 Median: -3.53 Standard Deviation:

2.85 Range: -6.11 to 6.8 Page 6 of 9 FSS Summary Report F8100041 Survey Unit Data Assessment:

The survey design required 38 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 7 of 9 FSS Summary Report F8100041 Table 4. Data Assessment Results Survey Results Parameter Value Comment Material Background Used (dpm/1'00 cm 2): N/A Ambient Background Used (dpm/100 cm 2): N/A Average Ambient BKG = 0 Actual Direct Measurements (N): 38 Median (dpm/100 cm 2): 2588 Mean (dpm/100 cm 2): 2609 Direct Measurement Standard Deviation 232 (dpm/100 cm 2): Total Standard Deviation (dpm/100 cm 2): 232 Based on samples and backgrounds.

Maximum (dpm/100 cm 2): 3118 Material Type: N/A Background Subtract Not Applied Sign Test Final N Value: 38 S+ Value: 38 Critical Value: 24 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 8 of 9 FSS Summary Report F8100041 Survey Unit Investigations and Results: Two investigations (JS06 and JS45) were required for the scan measurements and the results are reported in Attachment

3. The EMC unity rule was not exceeded as shown in Table 3-1.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 I 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. Two potential areas of elevated activity were detected and evaluated as shown in Attachment

3. 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 meastirements 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. The required investigations were performed and evaluated.

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 F8100041 meets the release criteria of 1OCFR20.1402.

Page 9 of 9 FSS Summary Report F8100041 Attachment 1 Maps October 29, 2008 Survey Unit F8100041 0 ý00-- ---- ------- -- --- 1 i 'N CST PAD P..-T cs A.I 0 Z!Asphalt NZ N-------------------

RC ST PAD///" ,'-.jH3EVAP 1PAD i S / , BWST PAD (Zone 3 one 1/F'~m,-.. //"\~.-J 1L,'N "'- ~//4 //>1 7 N' /,./Reactor k S:MUD SAC'RAAENjTO-t.IHCIPAI.

SCALE METERS 0 5 1 TANK FARM -CONCRETE PADS GENERAL ARRANGEMENT PLAN VIEW F8100041-Mi SHEET 1 OF2 0 7/,/, Vertical Surface Details 0 E~jEw-L E-.LA ,g ,u'Pad 3 a>1 4/ ~(\J 771 111 Lt~t H CST PAD CST Pad 1 Pprl A Pad 5 00 0 0 0 C)C)Surface Ar-, Es:natýs Co.aew ~ 189.1 n stael6fLn9 Total "491,1n'Scale Feet 3"= 11-0" Scale Meters 0 1 2 3 9'SMUD SACRAJý.Er j ( r)~UTILITh DIS' RICV TANK FARM -CST PAD PLAN / ELEVATION VIEW SURFACE AREA ESTIMATE F8100041-Mi SHEET 2 of 2 7 -I 4+f4 fHi444H I A. f '+44 A--'- A-H -'AH L 4- 4 4rA4~A4A'r44, l'44.,4H4-H-'4 44 H~A~r AtT J-4 ~ ~ ~ ~ ~ ~ ~~I +- -` i11VH 4H ,+ 1i41i4ý !ýi ii1i+ -~I'7~~ ~ T- _____T--A4,4 Ti A~.t ~ H-H.4 it ~44,~s 4.~1~+/ / 4'-N 47 I" fA H+4A-f H H H ! itlH H H H 3 1.- 111.11- 11 ..I I .I .I I .I .11 -..i i i i ; i i iimý4.IL A --4 ~A~44-H+

H-A T4+/-AH4~' 4 4~ H'4-444-ii.44..

4- T L-4 4.4A~4-l4 41 If f;-4 +14 .4 441i4 f4 4 H i H4 1 .4..4lI.4..A4.T4.4.44 F- F, .r T I_;++4-l4i-44-"4+l-l+4ýA-fý

-. Hý++H 14"' ---j 4-; -f-H +H-H4-i J i j i-+/- f~I.1 4 :-,+i" 4142 ., I 4 A 4-- +.I ~1+.;." l 4-i--l i t 1 -H441-1ý41.14

• HWHI44 HiA 444. f4 H 4i4-4 *4+ 4-,4 I.T 4 4444 4:. j1ilI J4+ .. f .:D14 4 +H1 t -~ 4-T74 Pad I It I--'L44 1! l I 4'i 1 1 4'II H H : H = i 414-4 j1 IL 4 \\ ~t +/-+ -!t, fl // +t 4.4H 4-x.IfT~ IL T T CT Padil4 7 L I ah4I Padý5 171-4 ' -i If cale Fet TANK FARM -CONCRETE PAD #1 IL BETA DIRECT--z RANDOM START LOCATION TSL -RA -6 W u~ F8100041-M2 0 TJ2 00/\ /T-7 3/E~r~r it t2",/'--, 'I Ilk"23)16. is 16 F 1U1 (12 21 chd::7Z5 E2o 7 -~~~-~~~1 6L9 GD A L 06) 07 Pad 3 (37 ( 0 ,-Nj~II~CST Pad 1 ,;. ,/Pad 4 Pad 5 Scale Feet 32 1-o Scale Meters W SM u SACRAMENTO NAUHICIPAL.

0 1 2 3 UILIY D)S lIT TANK FARM -CONCRETE PAD #1 BETA DIRECT MEASUREMENT LOCATIONS F8100041-M2 SHEET 2 OF 2 (D 0 W-1 N 1K 0 2 L, ~ 028 V PAH 9 045 ~(7T) 'o (11 -7 N7 C Pad 3CST Pad 1 1 44 P;ad4_160 00 00 L Scale Feet 2= 1-0 Scale Meters 0 1 2 3 SAC V2AMENTOMUIPA U11Il' GISTRIOf TANK FARM -CST PADS #2 -#5 BETA SCAN W/43-37 MEASUREMENT LOCATIONS F8100041-M3 SHEET 1 of4 (0 0 (N;" (0901 1 08 3 '084 PA~d 9 i/Pad 3 K x , Includes Lops 014/(. 01_3 CST Pad 1 P 144 Pad 4"160 00 Co C)Scale Feet 32 : 1-0 Scale Meters 0 1 2 3 smug]TANK FARM -CST, PADS #2 -#5 BETA WITH GAMMA SCAN MEASUREMENT LOCATIONS F8100041-M3 SHEET 2 of4 (tD 00 0 00 HNrq\.-.._v;/Scale Feet Scale Meters 0 1 2 3)SACR/,AMEI0 MUNICIPAL UTLITY DISTRICT TANK FARM -CST PAD GAMMA SCAN DETAILED MEASUREMENT LOCATIONS F8100041-M3 S E ET 3 of 4 CD 0 00 33 1-02 101 -10"'0OW'-~' .~A~' ( 0013C-T =-9-- Pad 2 A\l~J~08088 t27 n:.:, i- ", 2 i i \ / \107 103_L .-1 , Pad 4 245= suppli.-nip.1~

beta scanpok~s.4),13-37

---

----------------

Scale Feet Scale Meters 0 1 2 3 (USMUGD SCRAML7 IT13 IT 1STI TANK FARM -CONCRETE PAD #1 BETA SCAN W/O 43-37 MEASUREMENT LOCATIONS F8100041-M3 SHEET 4 of4 (D 0 io43-51 on/ -%< cre~Pad 2 7 J 35 jz~z~~ -41 38 37 '41 Pad 3 40 42 A/, 44 4-P Pad 5 CST Pad 1 Pad 4 00 C-).Scale Feet Scale Meters i SM UD MACRAM UNICiPAL 0 1 2 3 iTLT'D~~C TANK FARM -CST, PAD #2 -#5 JUNCTURE SCAN MEASUREMENT LOCATIONS F8100041-M4 SHEETi OFI (6 0-t...2//Pl "pP 1 2 Pad 2 PW\\II P13 P14 9t- 9H2-F-J Pad 3 A'>'* ___________,_

,_ _ __ _ __ _/ ,/// \~.A/' # ~~ K<\ 'K\~<K 7;/'K i/ , P?3, P05 frzl P-04 0 Fu-I 1,-S J P15 P16 E117 P18 b.%~%* \>CST Pad 1'VA Pad 4 ITJ 00 Pad 5 Scale Feet=I-o..Scale Meters 0 1 2 3*mu*AýR IJEN) ( UNICIPAL;Jl-'! DS- R P T~TANK FARM -CONCRETE PAD #1 PENETRATION SCAN MEASUREMENT LOCATIONS F8100041-M5 SHEET 1 OF 3 (D P03 P05 P04 P06\j I-00°" Top 12' of conduit P08 removed for survey -remainder abandoned in place P08.P07 P07 0 P09 Plo P01 P02" 7" .00 C: ,, SMUD I SACf-AjFNTi0 MUNICIPAL.

TUTLIT' DISTI;TU TANK FARM -CONCRETE PAD #1 PENETRATION SCAN MEASUREMENT LOCATIONS F8100041-M5 SHEET 2 OF 3 CD 0 00 P13 P14 I -Pll -- P12 Pad 2 P15 P16 P17 P18-I i /....... ............

..Pad 5-i i i~ '.. ii l~

_- i ! i. , Pad 5 F <iL"/, /-----.---

___ __--LILX Pad 3 smu SARME11)UDNCI AT'LT CAH 4 ICT P TANK FARM -CONCRETE PAD #1 PENETRATION SCAN MEASUREMENT LOCATIONS F8100041-M5 SHEET 3 OF 3 Attachment 2 Instrumentation October 29, 2008 Survey Unit F8100041 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; 180733 43-98B; 148638 8 2 0 A 1490A M2350; 180733 43-94B; 148620 950B 1660 M2350; 203482 43-68B; 178510 M2350; 189089 43-68B; 161406 1033 M2350; 193715 43-68B; 148630 M2350; 180738 43-51B; 190666 990, 2313D Tennelec; 0401171 N/A 6 dpm a, 12 dpmr N/A A 43-98B penetration

-metal -4" B 43-94B penetration

-metal -1" c 43-94B penetration

-metal -2" D 43 -51B juncture -concrete Table 2-2. Investigation Criteria and DCGL Value Parameter d aluc (dpm/100 cm 2)Investigation Criteria -Direct 43000 E Investigation Criteria -Scan 43000 E DCGLw 43000 DCGLEMC 152901.E Set conservatively at DCGLw Page 2 of 2 Att. 2 Instrumentation F8100041 Attachment 3 Investigation October 29, 2008 Survey Unit F8100041 Table 3-1 Survey Unit Investigation Investigation Initial Value Investigation Elevated Area Investigation DCGLemc aResult Area (m) Factor DCGLemc Result Unity Level (cpm) (cpm) (cpm) (dpmlOOcm2)

Fraction JS06 1100 1534 1534 0.01 1294.1 55,646,300 59,862 0.001 JS45 1100 1843 1843 0.20 66.89 2,876,270 71,920 0.025 Survey Unit Remainder DCGL = SU Mean = 0.061 43,000 2609 EMC Unity Sum 0.086 Page 2 of 2 Att. 3 Investigation F8100041 Attachment 4 Data Assessment October 29, 2008 Survey Unit F8100041 F8100041 Gross Activity Sample Results Quantile Plot tQ DCGL = 43000 dpm/100cm' 31500 ~. 4~44 3,000 -- .-4. --4-.-..4 -------------------2 ,5 0 0 -------....-.--

-....2~2,000,

... ...== ..... ,... -,= =+.4 .-o= .... -' .. -.-o. ... 4-- ... .,. .CD1,000 4 --4 .444~0 0 20 40 60 80 100 Percentile l00 Direct Measurements (dprn/I00cm2)

-median 75th Percentile

-.-- 50th Percentile

-e 0F8100041 Gross Activity Sample Results Scatter Plot DCGL = 43000 dpml001cm 1 A 0 U)U)a U)a 3500 -N-3000 E 2500-2000 CL E1000 500 n a a a -a a a --a -a a a a a --a -a -w -.a " 0 0 0 0 0 00 -0 o 0 0 0 0 0 0 0 3304 260S 1914 0 0 0 a --- --.-.-.-.-

-... ......- -- ----- --..- --------i A i i 6 i l i i i i i iA I I i'U I J I I I 1

• j I 1 1 1 ~cicocoocccoooccooccocoococoaoooooccoaoo rC¶4tV) it NCO00rNO (ON Cr (ONCQ0CrNO it IDWNCO 0000 OCCOCrrrrr rrrNtJ NCJNNNNCQO')0 00000 00000000000000000000000000000000000000 000000000000000000000000000000000000 00 uoUoouUoououuoUoUouuuuuououuuuuuuUouuo Measurement Locations-r cc (D C C C A: o Gross Activity -Average- -"+3StDev" -.-3SDev" (D~00 F8100041 Gross Activity Frequency Plot DCGL = 43000 dpmn/1 00cm 2 1 1 1 1 LL C 0 3 2 1 0 9 8 7 6 5 4 3 2 1 0 COj O4 (I40 0)0 N-(NJ CO CO Bins -Upper End Value (dpm/1 00cm2)