ML090830573

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Final Status Survey Report for March 2, 2009, Tank Farm SW Quad, a Steam Sump & Sf Cooler Pad Areas, Survey Unit F8100011
ML090830573
Person / Time
Site: Rancho Seco
Issue date: 03/02/2009
From: Tallman D
Sacramento Municipal Utility District (SMUD)
To:
NRC/FSME
Shared Package
ML090830613 List: ... further results
References
DPG 09-097, F8100011
Download: ML090830573 (24)
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Rancho Seco Final Status Survey Summary Report March 2, 2009 Tank Farm SW Quad, "A" Steam Sump & SF Cooler Pad Areas Survey Unit F8100011 Prepared By: Dan A. Tallman

  • 7Date:

March 2, 2009 FSS Engineer Reviewed By:

Date:3 1 O Lead FSS Engineer Approved By: 6<7/Z Date:

Dismantlement Superintendent, Radiological

FINAL STATUS SURVEY

SUMMARY

REPORT Survey Unit:

F8100011, Tank Farm SW Quad, "A" Steam Sump & SF Cooler Pad Areas Survey Unit

Description:

Operating History: The area surrounded the tanks used to store radioactive liquids. This area was used for the storage of radioactive material. Operating records and the HSA document several events with the potential for a release of radioactivity associated with this survey area. The HSA documented the storage of radioactive material within the area'that may have had the potential to contaminate the area.

Records of soil samples taken near the BWST showed soil contamination levels as high as 230 pCi/g prior to remediation.

Site Characterization: Soil samples 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 land 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 672 m2 were scanned for 100% coverage. Soil samples were collected at each direct measurement location and analyzed by HPGe detector while locations falling on asphalt were measured using In-Situ Gamma Spectroscopy. 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 8 FSS Summary Report F8100011

Table 1. Survey Unit Design Parameters Survey Design Parameter Value Comment Survey Area:

F810 Tank Farm SW Quad, "A" Steam Sump & SF Cooler Pad Areas Survey Unit:

0011 Open Land Area Class:

1 LTP Table 5-4 SU Area (ml):

672 Evaluator:

D.A.Tallman DCGL for Cs-137 surrogate (pCi/g):

52.6 DCGL for Co-60 (pci/g):

12.6 Area Factor:

1.4 Class 1 Design DCGLemc (pCi/g):

74.2 Class 1 LBGR (pCi/g):

25.6 Adjusted Design Sigma (pCi/g):

10.7 DTBD-06-001, Table 5-4A or B Type I Error:

0.05 Type II Error:

0.05 Sample Area (m2):

44.8 Class 1 Total Area Scanned (m2):

672 Scan Coverage (%):

100%

Class 1 Zl., :

1.645 Zl-P :

1.645 Sign P:

0.99379 Calculated Relative Shift:

2.5 Relative Shift Used:

2.5 Uses 3.0 if Rel Shift >3 N-Value:

12 Design N-Value + 20%:

15 NUREG-1575 Table 5-5 Grid Spacing L:

6.7 Class 1 Page 3 of 8 FSS Summary Report F8 100011

Survey Results:

A total of 20 direct measurements were made in F8 100011. The results are shown in Table 2-1. Statistical data including the mean, median, and standard deviation are shown in Table 2-2. All of the direct measurements were less than Unity. Thirty-Six (36) of the scan measurements indicated areas of elevated activity with an observed scan range of 4990 - 242929 cpm with the 44-10 Nal detector. Measurements were counted to the MDCs shown in Table 2-1 of Attachment 2.

Page 4 of 8 FSS Summary Report F81 00011

Table 2-1. Direct Measurement Results (all activity values in pCi/g)

Unity Unity Unity Sample ID MDA Activity Uncertainty Value MDA Activity Uncertainty Value Total F8100011SOO01SS 6.23E-02 1.67E00 1.21E-01 0.0318 6.85E-02

<6.85E-02 0.0054 0.0372 F8100011S0002SS 7.82E-02 4.34E-01 7.52E-02 0.0083 5.45E-02

<5.45E-02 0.0043 0.0126 F8100011S0003SS 5.22E-02 2.04E-01 4.95E-02 0.0039 5.76E-02

<5.76E-02 0.0046 0.0084 F8100011S0004SS 5.32E-02 1.10E-01 4.19E-02 0.0021 6.42E-02

<6.42E-02 0.0051 0.0072 F8100011S0005SS 7.99E-02 1.52E00 1.24E-01 0.0289 5.56E-02 1.51E-01 4.12E-02 0.012 0.0408 F8100011SO006SS 5.30E-02 4.88E-01 6.66E-02 0.0093 7.12E-02

<7.12E-02 0.0057 0.0149 F8100011S0007SS 4.67E-02 1.09E-01 3.83E-02 0.0021 4.37E-02

<4.377E-02 0.0035 0.0055 F8100011S0008SS 5.22E-02 7.92E-01 8.01E-02 0.0151 6.45E-02

<6.45E-02 0.0051 0.0202 F8100011S0009SS 5.95E-02 2.45E-01 5.44E-02 0.0047 5.29E-02

<5.29E-02 0.0042 0.0089 F8100011SOO1OSS 5.75E-02 1.40E-01 4.61E-02 0.0027 5.75E-02

<5.75E-02 0.0046 0.0072 F8100011 A0IIGD 9.62E-01

<9.62E-01 0.0183 9.08E-01

<9.08E-01 0.0721 0.0904 F8100011SO012SS 5.20E-02 2.431E-01 5.02E-02 0.0046 4.22E-02

<4.22E-02 0.0033 0.008 F8100011S0013SS 4.88E-02 6.50E-01 7.64E-02 0.0124 6.07E-02

<6.07E-02 0.0048 0.0172 F8100011SO014SS 6.00E-02 3.75E-01 6.57E-02 0.0071 7.37E-02

<7.37E-02 0.0058 0.013 F8100011 AN015GD 1.OOEOO

<I.OOEOO 0.019 9.55E-01

<9.55E-01 0.0758 0.0948 F8100011SO016SS 5.03E-02 1.76E-01 4.58E-02 0.0033 4.85E-02

<4.85E-02 0.0038 0.0072 F8100011SO017SS 6.35E-02 4.76E-01 6.87E-02 0.0091 6.64E-02

<6.64E-02 0.0053 0.0143 F8100011SO018SS 5.61E-02 2.68E-01 5.62E-02 0.0051 6.911E-02

<6.91E-02 0.0055 0.0106 F8100011SO019SS 6.04E-02 1.55E-01 4.92E-02 0.0029 7.29E

<7.29E-02 0.0058 0.0087 F8100011SO02OSS 6.26E-02 6.88E-01 8.28E-02 0.0131 9.34E-02

<9.34E-02 0.0074 0.0205 Page 5 of 8 FSS Summary Report F8 100011

Table 2-2. Direct Measurements Results Summary CsC137 Co6i Activity Activity Cs137 Unity Co6O Unity Unity Total

  • w.,::

(pCi/g)

(pCilg)

DCGLw 52.6 12.6 Mean 5.35E-01 1.54E-01 0.0102 0.0122 0.0224 Median 4.05E-01 6.55E-02 0.0077 0.0052 0.0128 Standard Dvation 4.55E-01 2.67E-01 0.0087 0.0212 0.0258 DeviationI Cs137 Activity Range (pCi/g) 1.09E-01 to 1.67E00 Co60 Activity Range (pCi/g) 4.22E-02 to 9.55E-01 Cs137 Unity Range 0.0021 to 0.0318 Co60 Unity Range 0.0033 to 0.0758 Total Unity Range 0.0055 to 0.0948 Sample Count 20 Survey Unit Data Assessment:

The survey design required 20 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 6 of 8 FSS Summary Report F8100011

Table 3. Data Assessment Results Survey Results Parameter Value Comment Actual Direct Measurements (N):

20 Median (unity):

0.013 Mean (unity):

0.022 Direct Measurement Std Deviation (Unity):

0.026 Maximum (Unity):

0.095 Sign Test Final N Value:

20 S+ Value:

20 Critical Value:

14 Sufficient Samples Collected:

Yes Maximum Value < Unitized DCGL:

Yes Median Value< Unitized DCGL:

Yes Mean Value < Unitized DCGL:

Yes Maximum Value < DCGLemc (Unity):

Yes Class 1 Standard Deviation <= Sigma:

Yes Pass the Sign Test?

Yes Reject the Null Hypothesis?

Yes Does the Survey Unit Pass All Criteria?

Yes Page 7 of 8 FSS Summary Report F8 100011

Survey Unit Investigations and Results:

Thirty-Six (36) investigations (scan grids 01-07, 15, 16, 30, 34-45, 47, 48, 50, 51, 53-56, 58-60, 65, 66, & 77) 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 Unity. Thirty-six (36) 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 F8100011 meets the release criteria of 10CFR20.1402.

Page 8 of 8 FSS Summary Report F8100011 Maps March 2, 2009 Survey Unit F8100011

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MEASUREMENT LOCATIONS SACRAAEN9TO MUNI9OPAL F8 000 FIT T I DISRIC SHEE I f 2 M H9LL Page 4 of 7 Att. 1 Maps F8100011

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Table 2-1. Survey Unit Instrumentation Detector Detector Serial Instrument Model MDC No.No.

23 50-1 217583 43-68B 190482 1033

  1. 175834 23 50-1
  1. 17583 43-116 190642 793
  1. 175834 2350-1 256101
  1. 193700 44-10 171374 5-6 pCi/g 1,2
  1. 193715 171992
  1. 208481 HPGe N/A 05069128 Soil - 0.08 pCi/g Cs-137 Inspector N/A 08051294 Asphalt - 0.96 pCi/g Cs-137 Ludlum 2350-1 with Nal Detector MDA /investigation level sufficient to detect a 1 uCi discrete Co60 particle as detailed in "Discrete Particle Detection Using the Ludlum 2350-1m and 5.08 by 5.08 Nal detectors" RFD 3/27/07.

2 Ludlum 2350-1 w/ Nal detector (44-10/SPA-3) MDAfor distributed soil activity 6 pCi/g.

Table 2-2. Investigation Criteria and DCGL Instrument Parameter Value 2350/43-68B Investigation Criteria - scan 5,840 cpm 2350/43-116 Investigation Criteria - scan 4,260 cpm 2350/44-10 Investigation Criteria - scan 9000-10119 HPGe Investigation Criteria - direct Soil - 74.2 pCi/g Cs-137 Inspector Asphalt - 74.2 pCi/g Cs-137 All DCGLw 52.6 Cs-137 All DCG__w 12.6 Co-60 All DCGLEMC 74.2 (Cs137 s)

Depending on instrument-detector and survey media combination, 2350-1/44-10 Investigation Level calculated IAW DSIP-0510 (encl. 8.6)

Page 2 of 2 Att. 2 Instrumentation F8100011 Investigation March 2, 2009 Survey Unit F8100011

Table 3-1 Survey Unit Investigation Investigation Initial Investigation Elevated Area DCGLemc Investigation DCGLemc Grid Level Value Result Area (m2)

Factor Result Unity (cpm)

(Cpm) note1 (pCi/g)

Fraction 01 9000 13101 3577 (a)

N/A N/A N/A

< DCGLw N/A 02 9000 11399 4326 (a)

N/A N/A N/A

< DCGLw N/A 03 9000 11719 4618 (a)

N/A N/A N/A

< DCGLw N/A 04 9000 9972 3144 (a)

N/A N/A N/A

< DCGLw N/A 05 9000 18656 2626 (a)

N/A N/A N/A

< DCGLw N/A 06 9000 31680 9634 N/A N/A N/A

< DCGLw N/A 07 9000 242929 3009 (a)

N/A N/A N/A

< DCGLw N/A 15 9000 12417 4.2 pCi/g (d)

N/A N/A N/A

< DCGLw N/A 16 9000 9599 4729 (a)

N/A N/A N/A

< DCGLw N/A 30 9000 5947 MDA4 N/A N/A N/A

< DCGLw N/A 34 9000 10675 3203 (a N/A N/A N/A

< DCGLw N/A 35 9000 16346 0.107 (d)

N/A N/A N/A

< DCGLw N/A 36 9000 10282 3512 (a)

N/A N/A N/A

< DCGLw N/A 37 9000 9651 2729 (a)

N/A N/A N/A

< DCGLw N/A 38 9000 9941 0.98 pCi/g (d N/A N/A N/A

< DCGLw N/A 39 9000 20766 3.81 pCi/g (d)

N/A N/A N/A

< DCGLw N/A 40 9000 10031 3948 (a)

N/A N/A N/A

< DCGLw N/A 41 9000 9800 3526 (a)

N/A N/A N/A

< DCGLw N/A 42 9000 10204 3713 (a)

N/A N/A N/A

< DCGLw N/A 43 9000 9480 8936 (b)

N/A N/A N/A

< DCGLw N/A 44 9000 10994 3946 (a)

N/A N/A N/A

< DCGLw N/A 45 9000 14590 37.7 pCi/g (d)

N/A N/A N/A

< DCGLw N/A 47 9000 9957 3793 (a)

N/A N/A N/A

< DCGLw N/A 48 9000 9654 3835 (a)

N/A N/A N/A

< DCGLw N/A 50 9000 9980 3990 (a)

N/A N/A N/A

< DCGLw N/A 51 9000 10171 3936 (a)

N/A N/A N/A

< DCGLw N/A 53 9000 10041 3645 (a)

N/A N/A N/A

< DCGLw N/A 54 9000 10195 3915 (a)

N/A N/A N/A

< DCGLw N/A 55 9000 9805 3763 (a)

N/A N/A N/A

< DCGLw N/A 56 9000 9618 3195 (a)

N/A N/A N/A

< DCGLw N/A 58 9000 9200 3555 (a)

N/A N/A N/A

< DCGLw N/A

Table 3-1 Survey Unit Investigation (Continued)

Grid Investigation Initial Value Investigation Elevated Area DCGLemc Investigation DCGLemc Level (cpm)

Result Area (m2)

Factor Result (pCi/g)

Unity (cpm) note1 Fraction 59 9000 9920 3601 (a)

N/A N/A N/A

< DCGLw N/A 60 9000 9598 3359 (a)

N/A N/A N/A

< DCGLw N/A 65 9000 9064 3512 (a)

N/A N/A N/A

< DCGLw N/A 66 9000 9597 8910 (b)

N/A N/A N/A

< DCGLw N/A.

77 9000 9061 8579 (b)

N/A N/A N/A

< DCGLw N/A Notes:

1activity units media/instrumentation dependent.

(a)= static counts w/44-10 (b)= scan latch mode counts per minute (cpm)

(c)= InSpector 1000 pCi/g Cs137 (d)= HPGe soil sample pCi/g Cs137 2 Post remediation 3 Identification and isolation of metal fragment debris (0.39 uCi Co60) 4 MDA = 1.25 pCi/g Cs-137, 1.27 pCi/g Co-60 5 Identification and isolation of concrete coring debris (0.07 uCi Cs137) 6 Identification and isolation of gravel debris (63 pCi Co60) from sample scree 7 Identification and isolation of gravel debris (0.157 uCi Cs136) from sample scree Survey Unit Remainder DCGL =

SU Mean N/

N/A EMC Unity Sum N/A Data Assessment March 2, 2009 Survey Unit F8100011

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0 cj) 00 F8100011 Quantile Plot 0I-N 0.100 0.090 0.080 0.070 0.060 0.050 0.040 0.030 0.020 0.010 0.000 0.013 0

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  • Unitized Total Value -Median

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0 Bins-Upper End Value (Unitized Total)

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