ML090830542

Final Status Survey Report for October 16, 2008, Pump Alley Access Corridor, Survey Unit F8000104

ML090830542
Person / Time
Site:	Rancho Seco
Issue date:	10/16/2008
From:	Tallman D A 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, F8000104
Download: ML090830542 (23)

Text

Rancho Seco Final Status Survey Summary Report October 16, 2008 Pump Alley Access Corridor Survey Unit F8000104 Prepared By: Dan A. Tallman , _ Date: October 16, 2008 FSS Eng neer Reviewed By: te: (0 712- /62 Lead FSS Engineer Approved By: I-- Date: i?Dismantlement Superintendent, Radiological FINAL STATUS SURVEY

SUMMARY

REPORT Survey Unit: F8000104, Pump Alley Access Corridor Survey Unit

Description:

The Survey Unit consists of the asphalt pavement between the Auxiliary Building and the T&R building.

Packaged demolition debris from the AB pump alley remediation has routinely been transported through the survey unit via the access plug posing the potential for a small amount of contamination to be deposited within the survey unit. During routine surveillance surveys; documented evidence of contamination (single particle 0.05 uCi Co60) adjacent to the pump alley access plug was discovered.

This isolated area of contamination and the increase potential in the immediate vicinity resulted in the area being designated as a unique survey unit (8000104).

Site Characterization:

Paved areas were surveyed and found to have a mean value of 2,261 dpm/100 cm 2 and a maximum of 3,930 dpm/100 cm 2.Based on classification procedure (DSIP-0020) and the discovery made during the surveillance survey, the pump alley access corridor between the T&R and Auxiliary buildings is 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 248 m 2 were scanned for 100% coverage.

Direct gamma spectrum were collected at each direct measurement location and analyzed by ISOCS. 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 7 FSS Summary Report F8000104 Table 1. Survey Unit Design Parameters Survey Design Parameter Value Comment Survey Area: F800 Pump Alley Access Corridor Survey Unit: 0104 Open Land Area -Paved Class: 1 LTP Table 5-4 SU Area (m2): 248 Evaluator:

D.A.Tallman DCGL Cs137 surrogate (pci/g): 51.2.Area Factor: 1.9 Class 1 Design DCGLemc (pCi/g): 97.8 Class 1 LBGR (pCi/g): 49.49 Adjusted Design Sigma (pCi/g): 0.57 DTBD-06-001, Table 5-4C (expressed in pCi/g)Type I Error: 0.05 Type II Error: 0.05 Nuclide: Cs137 Sample Area (m2): 17.7 Class 1 Total Area Scanned (m2): 248 Scan Coverage (%): 100% Class 1 Zl-, : 1.645 ZI-p : 1.645 Sign P: 0.99865 Calculated Relative Shift: 44.9 Relative Shift Used: 3 Uses 3.0 if Rel Shift >3 N-Value: 11 Design N-Value + 20%: 14 NUREG-1575 Table 5-5 Grid Spacing L: 4.2 Class 1 Page 3 of 7 FSS Summary Report F8000104 Survey Results: A total of 14 direct measurements were made in F8000104.

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

Scan measurements ranged from 10,146 cpm to 11,639 cpm. Direct Measurement samples were counted to the MDC shown in Table 2-1 of Attachment 2.Table 2. Direct Measurement Results (all activity values in pCi/g)Measurement ID Cs137 MDA Cs137 Activity Uncertainty Mean.:~> 1.04E00 Median:v; 1,04E00 Standard Deviation:

4.30E-02 _________Range: 9.77E-01 to 1.09E00 F8000104 AOO01GD 1.04E00 < 1.04E00 F8000104 A0002GD 1.02E00 < 1.02E00 F8000104 A0003GD 1.03E00 < 1.03E00 F8000104 A0004GD 9.89E-01 < 9.89E-01 F8000104 A0005GD 9.77E-01 < 9.77E-01 F8000104 A0006GD 9.82E-01 < 9.82E-01 F8000104 A0007GD 1.03E00 < 1.03E00 F8000104 A0008GD 1.09E00 < 1.09E00 F8000104 A0009GD 1.08E00 < 1.08E00 F8000104 A0010GD 9.84E-01 < 9.84E-01 F8000104 A0011GD 1.07E00 < 1.07E00 F8000104 A0012GD 1.09E00 < 1.09E00 F8000104 A0013GD 1.06E00 < 1.06E00 F8000104 A0014GD 1.09E00 < 1.09E00 Page 4 of 7 FSS Summary Report F8000104 Survey Unit Data Assessment:

The survey design required 14 direct measurements for the Sign Test. The critical value and the results of the Sign Test are presented in Table 3. 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 5 of 7 FSS Summary Report F8000104 Table 3. Data Assessment Results Survey Results Parameter Value Comment Actual Direct Measurements (N): 14 Median (pci/g): 1.04E00 Mean (pCi/g): 1.04E00 Standard Deviation (pCi/g): 4.30E-02 Maximum (pci/g): 1.09E00 Sign Test Final N Value: 14 S+ Value: 14 Critical Value: 10 Sufficient Samples Collected:

Yes Maximum Value < DCGL: Yes Median Value < DCGL: Yes Mean Value < DCGL: Yes Maximum Value < DCGLemc: Yes Class 1 Standard Deviation

<= Sigma: Yes Pass the Sign Test? Yes Reject the Null Hypothesis?

Yes The survey unit passes all conditions?

Yes Page 6 of 7 FSS Summary Report F8000104

-Survey Unit Investigations and Results: Three investigations (scan grids 03, 09, & 10) 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 1 land 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. 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 measurements was made and the scan coverage met the requirement of Table 5-6 of the LTP. All of the direct measurements were less than the DCGL. The investigations required were performed and evaluated as detailed in attachment 3.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 F8000104 meets the release criteria of 1OCFR20.1402.

Page 7 of 7 FSS Summary Report F8000104 Attachment 1 Maps October 16, 2008 Survey Unit F8000104 j YARD KEY PLAN 9E6814239 E681ý4.2.

a N1888820 886 E6813442 z b> N1888650N/

N IE;86 E81814E6814152-4s217 NI 855 l 8633 E 81423 N18886Z6 N1888782\m8885551888517 EE61817E442321 E 6813 5546148 6848 08 N18886Nt888382 N1888382 NI888382 N1888382 E 5 SACRAMENTO MUEICIAL1 SCALE UTILITY DISTRICTF0O14-M1 METERS FILE: 800010 PACI cf Z RC RAYMOND 0 00 h IA ACENTRA'YARD N18887f9 INtg88817"------

E6132 E6814239 E68.13442.-

N1888820> N18886508 E68113313 N188863 N1N1888743~

6E6814153 rA -1 a1588814 N1E6814239-00000F0000i04 E6E613631 FBO13217 0 N1888162 N18886 EX00D 000 E68140622 E6187E5B132207 WooBE68135 E 442CEU13495 EE813799 E681'480 06814080 00 E881 3442ýN1888382 N1888 42 N188 382 N1888382 SCALE UTILIY DISTRICT *F80001 04-6M 1 METERS ARRANGECENT MEESFIILE:

800010 PAUF 9 of -i RC RAYMOND 00 KEY PLAN O0 00 0 0 0Surface Area Estimates Asphalt 248 m2 PUMP ALLEY ACCESS CORRIDOR GENERAL ARRANGEMENT SURFACE AREA ESTIMATE F8000104-Mi Total 248 m2*mn SACRAMENTO MUNICIPAL UTILITY DISTRICT

+ I I+llllll~~~~~~~..

.. .. .. .... ......ll l l l i l l l l l l l l l l l l 'l l l l 'l l : l l ll l l l l l l, l l ll : -_l l : l T~ Trt T .. ..T- +4AH* .1+ T + + :#14 FELL OUTSIDE SUID BOUNDARIES I I R 14 LOCATED WITHIN 1 METER OF DESIGNATED RANDOM LOCATION.i4. /8.5 SEL .EPLACEMFz4T ON 0/f+2 0 II I::.. ... .I .. ..4. .... +ý5 SE. /2 ° ,A, R +.. .4 .............i*I. : .... .. ... , ..I. ..1, ...... I ...... .. : -', I I ...... ' ... .. .... .. ._/.. .......,, ,,,..,....

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o PUMP ALLEY* ACCESS CORRI.OR T DIE TMESR EN...t H--I...-I H-I-H-H-It-I-Iit-- -It-H-I- H4H S M1 U RANDO-M START POINT.SACRAMENTO MUNICIPAL F 1 0 1 DISTRICT F000 -M.____- _______: ____ __:__________

_ ___________ -FILE: 800010 PACT 1 of 2 C RAYMOND..........! .i .I .5 .....

C)00 KEY PLAN f14 FELL OUTSIDE SUID BOUNDARIES R 14 LOCATED WITHIN I METER OF DESIGNATED RANDOM LOCATION 47/8.5 SELECTED AS REPLACEMENT ON 9/20/2008/ i 23"-0" C/)3 '-- 7" 1 .i 12 R 14~09~0)0 05 04 01 07p 0,6. 030 14 13 11~Or1 00 PUMP ALLEY ACCESS CORRIDOR DIRECT MEASUREMENT

.LOCATION DETAIL SACRAMENTO MUNICIPAL F8000104-M2 UTILITY DISTRICT F8 2__________________

FILE: 8000o10 PAGF ? of 7 RC RAYMOND (D 0-t 00 r1 KEY PLAN osmu*SACRAMENTO MUNICIPAL UTILITY DISTRICT PUMP ALLEY ACCESS CORRIDOR ISOCS GAMMA SCAN LOCATION DETAIL F80001 04-M3 0 00 cjn KEY PLAN//I! ~~6 1__15 07_________

03 1 O3//06 14 57.al 09 00*sun SACRAMENTO MUNICIPAL UTILITY DISTRICT PUMP ALLEY ACCESS CORRIDOR DISCRETE PARTICLE/GAMMA SCAN LOCATION DETAIL F80001 04-M3 FILE: 800010 PAC,'F ? ýf ? RC RAYMOND FILE: 800010 PAGF 2 of 2 RO RAYMONDI Attachment 2 Instrumentation October 16, 2008 Survey Unit F8000104 Table 2-1. Survey Unit Instrumentation Instrument Detector Detector Serial MDC Model No. No.Asphalt Inspector N/A 08051294 1.09 pCi/g Cs-137 1.14 pCi/g Co-60 Instrument Detector MDC Model; Serial No. Model; Serial No.M2350; 193715 44-10; 171374 5.26 pCi/g'Based on DTBD 05-12, Attachment 8.7 (w/ detector 2" above survey surface) 9000 cpm background.

Table 2-2. Investigation Criteria and DCGL Instrument Parameter Value Investigation Criteria -Asphalt -51.2 pCi/g Cs- 137(SUr.)Inspector Direct Asphalt -Detectable Co-60 All DCGLw 51.2 pCi/g Cs-137(sur.)

12.6 pCi/g Co-60 All DCGLEMC 97.8 pCi/g Cs-137(surf.)

2 Based on the mean background plus 3 standard deviation for a count rate of 11,200 cpm.(901]cpm + 3 * (60 (9011/60)A 0.5) = ll,217cpm)a a DSIP-05 10, enclosure 8.6 Page 2 of 2 Att. 2 Instrumentation F8000104 Attachment 3 Investigation October 16, 2008 Survey Unit F8000104 Table 3-1 Survey Unit Investigation T DCGLemc Investigation Initial Value Investigation Elevated Area DCGLeo Investigation Fractn Grid Level (CPM) (CPM) Result Area (m2) Factor Result (pCi/g) Unity (p ci/g) Fato 03 11,200A 11,366 1.01/1.03B NA NA NA < DCGLw 0 09 1 1 , 2 0 0 A 11,639 1.09/1.08B NA NA NA < DCGLw 0 10 1 1 , 2 0 0 A 11,299 1.07/1.06B NA NA NA < DCGLw 0 Survey Unit Remainder DCGL = SU Mean =51.2 1.04 EMC Unity Sum N/A A 11200 cpm (conservative approximation of 11,217 cpm as calculated JAW DSIP-0510 encl. 8.6)B InSpector 1000 2x2 Nal MDA Co60/Cs 137 Page 2 of 2 Att. 3 Investigation F8000104 Attachment 4 Data Assessment October 16, 2008 Survey Unit F8000104

('D.ITI 00 F8000104 Quantile Plot Cs137 DCGL = 51.2 pCi/g (-)3 C., 1.100 1.080 1.060 1.040 1.020 1.000 0.980 0.960 1.035 0 20 40 60 Percentile 80 100* Activity -Median --75th Percentile

---50th Percentile (D CD Wj 00 F8000104 Scatter Plot Cs137 DCGL = 51.2 pCiIg 1.40E+00 1.20E+00 --------------------------------------------

15? C O 00 1.OOE+00 o o-.. ......................)909 C 8.00E-O1; 6.OOE-01< 4.OOE-01 2.00E-01 0.002+00 Measurement Locations 0 Activity -Averaae --"+3StDev.

---3StDev-I I CD41 F8000104 Frequency Plot Csi 37 DCGL = 51.2 pCi/g 6 C: g4 TU U-c 3 0 S2 (U 0 N X, 0XQ0 &0 x N qz(ýBins -Upper End Value (pCi/g)