ML090850561
| ML090850561 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 10/09/2008 |
| From: | Tallman D Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| Shared Package | |
| ML090830613 | List:
|
| References | |
| DPG 09-097 | |
| Download: ML090850561 (21) | |
Text
Rancho Seco Final Status Survey Summary Report October 9, 2008 Industrial Area Railway Survey Unit F8340012 Prepared By: Dan A. Tallman Date: October 9, 2008 FSS Engindr Reviewed By: ____ __ _ _ Date:
Lead FSS Engineer Approved By: _ _ _ _ _ Date: Ž72 7 Dismantlement Superintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit:
F8340012, Industrial Area Railway Survey Unit
Description:
The Survey Unit consists of the rail system used to transport radioactive material from the site to the out of state waste disposal facilities. Even though the packages met DOT requirements for shipment, there is the potential for a small amount of contamination to be deposited along the rail right of way. There were no reports of rail contamination in the HSA however, during characterization surveys; documented evidence of contamination along the rail spur near the Turbine building was discovered. This isolated area designated as a unique survey unit (8340011) and is being evaluated separately.
Site Characterization: A gas proportional detector was used to survey the asphalt surrounding the rail spur within the IA. The mean value for paved surfaces was 3,653 dpm/100 cm 2 with a maximum observed activity of 8,567 dpmr/100 cm 2 .
Based on classification procedure (DSIP-0020) and the characterization survey data, the rail spur (with the exception of 8340011), from the Industrial Area access control fence to the rail head north east of the turbine building is a class 2 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 2184 m2 were scanned for approximately 46% coverage. Gamma direct spectrum were collected at each direct measurement location and analyzed by ISOCS/GAA. 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 F8340012
Table 1. Survey Unit Design Parameters Survey Design Parameter Value Comment Survey Area: F834 Industrial Area Railway Survey Unit: 0012 Open Land Area - Paved Class: 2 LTP Table 5-4 SU Area (m2): 4735 Evaluator: D.A.Tallman DCGL Cs137 surrogate (pCi/g): 51.2 Area Factor: N/A Class 2 Design DCGLemc (pCi/g): N/A Class 2 LBGR (pCi/g): 49.55 Adjusted Design Sigma (pCi/g): 0.018 DTBD-06-001, Table 5-4B Type I Error: 0.05 Type II Error: 0.05 Nuclide: Cs137 Sample Area (m2): 338.2 Class 2 Total Area Scanned (m2): 2184 Scan Coverage (%): 46.1% Class 2 ZI_, : 1.645 ZI-p : 1.645 Sign P: 0.99865 Calculated Relative Shift: 91.6 Relative Shift Used: 3 Uses 3.0 if Rel Shift >3 N-Value: 11 Design N-Value + 20%: 14 NIUREG-1575 Table 5-5 Grid Spacing L: 18.4 Class 2 Page 3 of 7 FSS Summary Report F8340012
Survey Results:
A total of 23 direct measurements were made in F8340012. The results including mean, median, standard deviation and range are shown in Table 2. All of the direct measurements were less than the DCGL. None of the scan measurements indicated areas of elevated activity with a scan range of< 0.265 pCi/g Co60 and 0.141 pCi/g - 0.286 pCi/g Cs 137. Gamma Direct measurements 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: 8.56E-01 ~ ~
Median: 8.47E-01 Standard Deviation: 5.09E-02 Range: 7.77E-01 to 9.47E-01 F8340012 A0001GD 8.41E-01 < 8.41E-01 F8340012 A0002GD 8.12E-01 < 8.12E-01 F8340012 A0003GD 8.20E-01 < 8.20E-01 F8340012 A0004GD 7.77E-01 < 7.77E-01 F8340012 A0005GD 8.55E-01 < 8.55E-01 F8340012 A0006GD 8.58E-01 < 8.58E-01 F8340012 A0007GD 9.47E-01 < 9.47E-01 F8340012 A0008GD 9.08E-01 < 9.08E-01 F8340012 A0009GD 9.39E-01 < 9.39E-01 F8340012 A0010GD 9.21E-01 < 9.21E-0t F8340012 A0011GD 9.24E-01 < 9.24E-01 F8340012 A0012GD 9.03E-01 < 9.03E-01 F8340012 A0013GD 7.87E-01 < 7.87E-01 F8340012 A0014GD 8.73E-01 < 8.73E-01 F8340012 A0015GD 9.12E-01 < 9.12E-01 F8340012 A0016GD 8.50E-01 < 8.50E-01 F8340012 A0017GD 8.39E-01 < 8.39E-01 F8340012 A0018GD 8.19E-01 < 8.19E-01 F8340012 A0019GD 8.14E-01 < 8.14E-0I F8340012 A0020GD 8.20E-01 < 8.20E-01 F8340012 A0021GD 7.89E-01 < 7.89E-01 F8340012 A0022GD 8.47E-01 < 8.47E-01 F8340012 A0023GD 8.26E-01 < 8.26E-01 Page 4 of 7 FSS Summary Report F8340012
Survey Unit Data Assessment:
The survey design required 23 direct measurements for the Sign 'rest. 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 greater the design standard deviation however both values result in a relative shift greater than three so no additional samples were required.
Page 5 of 7 FSS Summary Report F8340012
Table 3. Data Assessment Results.
Survey Results Parameter Value Comment Actual Direct Measurements (N): 23 Median (pCi/g): 8.47E-01 Mean (pci/g): 8.56E-01 Standard Deviation (pCi/g): 5.09E-02 Maximum (pCi/g): 9.47E-01 Sign Test Final N Value: 23 S+ Value: 23 Critical Value: 15 Sufficient Samples Collected: Yes Maximum Value < DCGL: Yes Median Value < DCGL: Yes Mean Value < DCGL: Yes Maximum Value < DCGLemc: N/A Class 2 Standard Deviation <= Sigma: Investigate Both values result in Relative Shifts greater than three, no additional samples required Pass the Sign Test? Yes Reject the Null Hypothesis? Yes The survey unit passes all conditions? Investigate No additional samples requires, all conditions pass Page 6 of 7 FSS Summary Report F8340012
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 2 land survey and the sample results are consistent with that classification. The variability of the survey results was greater than the characterization data used for survey design however, no additional sample were required. No potential areas of elevated activity were detected.
==
Conclusion:==
The FSS of this survey unit was properly designed as a Class 2 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. 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 F8340012 meets the release criteria of 10CFR20.1402.
Page 7 of 7 FSS Summary Report F8340012
Attachment1I Maps October 9, 2008 Survey Unit F8340012
(D Approximate surface area-2 4735 mn , including rotor shed and noith laydown area concretepads 00 INDUSTRIAL AREA RAILWAY w)
Scale: 1/128" = 1.0' GENERAL ARRANGEMENT PLAN VIEW Meter Scale *SMUD SACRAMENTO MUNICIPAL SURFACE AREA ESTIMATE 0 612 18 4 30 60 UTILITY DISTRICT F8340012-Mi FILE: 810001 SHEET 1 ofi TC HILL
0(
- ý: I D
- nEl
ýTl uo 00 INDUSTRIAL AREA RAILWAY 4ý.
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- Scale:1/128" -:.1.0' RANDON START POINT
- . Meter Scale oSMU*SACRAMENTO MUNICIPAL SOIL SAMPLES/DIRECT MEASUREMENTS K 06 12 1824 30 b 6 UTILITY DISTRICT F8340012-M2 810001 SHEET 1 of2 T(
10 I, 13 14
a 0
0-l 00 w::
INDUSTRIAL AREA RAILWAY 0
Scale: 1/128" = 1.0' Meter Scale 6 12 18 430 60
- SACRAMENTO MUNICIPAL UTILITY DISTRICT FILE: 810001 SOIL SAMPLE / DIRECT MEASUREMENT LOCATIONS F8340012-M2 SHEET 2 of 2 TC HILL
(TO 00 U>
INDUSTRIAL AREA RAILWAY Scale: 1/128" = 1.0' ISOCS SCAN Meter Scale *smu SACRAMENTO MUNICIPAL
.MEASUREMENT OVERVIEW 0 612 1824 30 60 UTILITY DISTRICT F8340012-M3 FILE:810001 SHEET 1 of 3 TO HILL
(0 0
'I 45 , e b.9 d IrJ 0
r1-1 06 INDUSTRIAL AREA RAILWAY 0 Scale: 1/64" = 1.01 ISOCS SCAN Meter Scale MEASUREMENT DETAIL SACRAMENTO MUNICIPAL 0 3 6 9 12 15 30 UTILITY DISTRICT F8340012-M3 SHEET 2 of3
(0 wj 27-4" 0
INDUSTRIAL AREA RAILWAY Scale: 1/64 = 1.0' ISOCS SCAN 0
Meter Scale oSMU*
SACRAMENTO MUNICIPAL MEASUREMENT DETAIL 36 912 15 30 UTILITY DISTRICT F8340012-M3 SHEET 3 of 3
Attachment 2 Instrumentation October 9, 2008 Survey Unit F8340012
Table 2-1. Survey Unit Instrumentation Detector Detector Serial Instrument Model MDC No. No.
Asphalt Inspector N/A 08051294 0.9,47 pCi/g Cs-137 1.02 pCi/g Co-60 Asphalt ISOCS N/A 1983920 0.385 pCi/g Cs-137 0.2.65 pCi/g Co-60 Table 2-2. Investigation Criteria and DCGL Instrument Parameter Value Asphalt ISOCS Investigation Criteria - Scan 20.0 pCi/g Cs-137 5.0 pCi/g Co-60 All DCGLw 51.2 Cs-137 12.6 Co-60 All DCGLEMC NA Page 2 of 2 Att. 2 Instrumentation F8340012
Attachment 3 Investigation October 9, 2008 Survey Unit F8340012 (none required)
Page 1 ofI Att. 3 Investigation
Attachment 4 Data Assessment Octobler 9, 2008 Survey Unit F8340012
(D.
F8340012 Quantile Plot Cs1 37 DCGL = 51.2 pCi/g 1.000 0.900 0.847 0.800 0.700 C.)
0.600 0.500 00 U 0.400 0.300 0.200 0.100 uj~
0.000 0 20 40 60 80 100 Percentile Activity - Median - - - 75th Percentile ... 50th Percentile
GO L*J 0
F8340012 Scatter Plot Cs137 DCGL = 51.2 pClIg 1.20E+00 1.00E+00 - 0 0 1.00-0 0 0 0 S.COE-01 --¢-oL,- S0-
-- -'--- -0o~
- 0-- 0.85 0.703 0 0 a.-------------------------------0.703 4.00E-01 ooo 2.00E-01 C'D O.OOE+O0 - i i i r-4 4-1-i Measurement Locations 0 Activity - Average - - "+3StDev'- -"-3SIDev" 00 C) w
-0
CD F8340012 Frequency Plot Cs137 DCGL = 51.2pCi/g CD 5.
CD
.0 U-0 0) 3-
_a W:j 01....
OI 1
04 N N N N N A$C/
4; 4; 4:
0)4/
ox Bins - Upper End Value (pCi/g) t'J