ML081610113
| ML081610113 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 03/18/2008 |
| From: | Donna Anderson Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| References | |
| F1000002 | |
| Download: ML081610113 (20) | |
Text
Rancho Seco Final Status Survey Summary Report March 17, 2008 Plant Effluent Water Course (SU2)
Survey Unit F1000002 Prepared By:
FSS Ena Date: __________
Reviewed By:
Date:
Approved By:
6" Date:
S' 7-or Dismantlement uperintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit:
F 1000002, Plant Effluent Water Course (SU2)
Survey Unit
Description:
Operating History: This area was the release point for liquid effluents released from the plant. The area was impacted by both planned and unplanned liquid releases. Effluents were monitored under the operating RETS/REMP program. Operating records and the HSA document the release of radioactivity in this survey area. The HSA recorded multiple unplanned release events.
Site Characterization: Soil and sediment samples were collected and analyzed for the presence of plant-derived radionuclides. Cs-137 was the predominant nuclide with a mean activity level of 9.2 pCi/g and a maximum value of 48.2 pCi/g. The Characterization data were found to be conservative when compared to the historical information found in the reports referenced in the PDP. Based on the classification procedure (DSIP-0020), the area was determined to be a Class 2 land area.
HSA Events: ODR-740017, 740052, 750046, 760079, 810192, 810193, 810209, 83008, 830023, 830248, 840117, 840118, 840225, 840223, 850299, 850112, 860555, 870764, 870905.
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 1,760 m2 were scanned for approximately 23% coverage. Soil samples were collected at each direct measurement location and analyzed by HPGe detector. 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 F1000002
Table 1. Survey Unit Design Parameters Survey Design Parameter Value Comment Survey Area:
F100 Plant Effluent Water Course (SU2)
Survey Unit:
0002 Open Land Area Class:
2 LTP Table 5-4 SU Area (m2):
7,744 Evaluator:
D. Anderson DCGL Cs137 surrogate (pCi/g):
51.2 Area Factor:
N/A Class 2 Design DCGLemc (pCi/g):
N/A Class 2 LBGR (pci/g):
25.6 Default = 50% DCGL Design Sigma (pCi/g):
14.7 DTBD-06-001, Table 5-4D Type I Error:
0.05 Type II Error:
0.05 Nuclide:
Cs137 Sample Area (m2):
455.5 Class 2 Total Area Scanned (m2):
1,760 Scan Coverage (%):
22.7%
Class 2 ZI, :
1.645 ZI-P :
1.645 Sign P:
0.955435 Calculated Relative Shift:
1.7 Relative Shift Used:
1.7 Uses 3.0 if Rel Shift >3 N-Value:
14 Design N-Value + 20%:
17 NUREG-1575 Table 5-5 Grid Spacing L:
21.3 Class 2 Page 3 of 7 FSS Summary Report F1000002
Survey Results:
A total of 17 direct measurements were made in F 1000002. 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. Soil samples were counted to the MDC shown in Table 2-1 of.
Table 2. Direct Measurement Results (all activity values in pCi/g)
Measurement ID Cs137 MDA Cs137 Activity Uncertainty Mean:
6.9 1E-0lI Median:
7.25E-02 Standard Deviation: j~<:
~~1.43 BOO Range:
5.79E-02 to 4.32E00 F1000002SOOO1SS 7.09E-02
< 7.09E-02 F1000002SO002SS 6.84E-02
< 6.84E-02 F1000002SO003SS 7.97E-02 4.32E00 3.68E-01 F1000002SO004SS 5.79E-02
< 5.79E-02 F1000002SO005SS 5.35E-02 5.87E-02 3.40E-02 F1000002SO006SS 5.81E-02 8.30E-02 4.27E-02 F1000002SO007SS 7.25E-02
< 7.25E-02 F1000002SO008SS 7.46E-02 4.20E00 3.49E-01 F1000002SO009SS 6.07E-02
< 6.07E-02 F1000002SOO1OSS 6.28E-02
< 6.28E-02 F1000002SO01ISS 9.34E-02
< 9.34E-02 F1000002SO012SS 7.01E-02
< 7.01E-02 F1000002SO013SS 5.41E-02 9.18E-02 6.03E-02 F1000002SO014SS 6.69E-02
< 6.69E-02 F1000002S0015SS 8.64E-02 2.07E00 1.72E-01 F1000002SO016SS 7.57E-02
< 7.57E-02 F1000002SO017SS
Survey Unit Data Assessment:
The survey design required 17 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 F1000002
Table 3. Data Assessment Results Survey Results Parameter Value Comment Actual'Direct Measurements (N):
17 Median (pCi/g):
7.25E-02 Mean (pCi/g):
6.91E-01 Standard Deviation (pCi/g):
1.43E00 Maximum (pCi/g):
4.32E00 Sign Test Final N Value:
17 S+ Value:
17 Critical Value:
12 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:
Yes Pass the Sign Test?
Yes Reject the Null Hypothesis?
Yes The survey unit passes all conditions?
Yes 1-Page 6 of 7 FSS Summary Report F1000002
Survey Unit Investigations and Results:
No investigationswere 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 less than the characterization data used for survey design. 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 F1000002 meets the release criteria of 10CFR20.1402.
Page 7 of 7 FSS Summary Report F1000002 Maps March 17, 2008 Survey Unit F1000002
0 SACPAMCNTO MUNICIPAL Smuo UTILFTY'DUTMOT FSS LOG-ATION-F100000 PLANT EFFLUENT WATER COURSE 6812170E 68122WE 1887242N C9 PLANT DISCHARGE 6912212E 6611675E I B87W&I do F1000001 EY UN CSR FLOW ESS" F1000002 SURVEY UN 7744SO 681236H 6812064E 10, 1887774N 6al 1917E laZ7.4OtJ 6611 665N 1887336ZE MAP F1 000002-1, SURVEY AREA CONFIGURATION TOTAL SIZE OF SURVEY AREA: 21.285 SQ M S510R15 UEiZIAI
0 CI A
SMUO RTo t FSS LOCATION:
Fl 000002 PLANT EFFLUENT WATER COURSE (SU2)
RVOGM START POWI 612256E I687e5iN MAP F1000002-2, SOIL LOCATIONS (DIRECT MEASUREMENTS)
FlO0 002SOOO1SS-Fl000002SG017SS SOIL SAMPLES 0 5 to 15 20
( DN SCALE kl METERS 1ý-
SMUD FSS LOCATION:
F1000002 SACRAMENTO MUNICIPAL PLANT EFFLUENT WATER COURSE (SU.2)
UTILITY DISTRICT 0 e468tO SCALE 14ETERS 9
.9 9
/
ISOCS FIELD OF VIEW, 28 m2 0N 5 METER CENTERS MAP F1000002-3. GAMMA SCANS Fl 000002SOOO1 GS-Fl 000002SOO75GS TOTAL SCAN;AREA:
1760 SO METERS 14ý*14i1 Page 4 of 6 Att. 1 Maps F1000002
SMUI3 FSS LOCATION:
F 1000002 SACRAMENTO MUNICIPAL PLANT EFFLUENT WATER COURSE (SU2)
UTILITY DISTICT 01 2345 SCALE METERPS ISOCS FIELD OF VIEW, 28 re 2
ON 5 METER CENTERS MAP F1000002-4, GAMMA SCANS F 1000002SO001OS-FiD000002SO046GS &
Fl.000002SO066GS-Fl10000020075GS TOTAL SCAN AREA:
1323 SQ -METERS Page 5 of 6 1
Att. I Maps F1000002
SMUDI FSS LOCATION:
F1000002 SACRAMENTO MUNICIPAL PLANT EFFLUENT WATER COURSE (SU2)
JTflL'rrY D ISRICT I
SCALE METERS
'IUAP F1000002-5, GAMMA SCANS Fl O00002S004-7GS-Fl 000002S0065GS TOTAL SCAN AREA:
437 SO METERS
[SOCS FIELD OF VIEEW, 2e r,;-
ON 5 METER CENTERS 1-1 ý Page 6 of 6 Att. 1 Maps F1000002 Instrumentation March 17, 2008 Survey Unit F1000002
Table 2-1. Survey Unit Instrumentation Detector Detector Serial Instrument Model MDC No.No.
HPGe N/A 9987008 Soil - 9.34E-02 pCi/g Cs-137 Soil - 9.17E-02 pCi/g Co-60 Soil - 8.64E-02 pCi/g Cs-137 Soil - 1.03E-01 pCi/g Co-60 ISOCS N/A 2983947 Soil - 4.16E-01 pCi/g Cs-137 Soil - 2.64E-01 pCi/g Co-60 Table 2-2. Investigation Criteria and DCGL Instrument Parameter Value ISOCS Investigation Criteria - Scan Soil - 20 pCi/g Cs-137 51.2 Cs-137 All DCGLw 12.6 Co-60 All DCGLEMC N/A Page 2 of 2 Att. 2 Instrumentation F1000002 Investigation March 17, 2008 Survey Unit F1000002 (none required)
Data Assessment March 17, 2008 Survey Unit F1000002
F1000002 Quantile Plot Csl37 DCGL = 51.2 pCi/g cTQ 0
ct~
U 0.
4-5.000 4.500 4.000 3.500 3.000 2.500 2.000 1.500 1.000 0.500 0.000 0
0 0.073 100 k) 20 40 60 80 Percentile I +
Activity -
Median -
- - 75th Percentile - - -
- 50th Percentile I
F1000002 Scatter Plot
-ClSl37 DCGL = 51.2 pClIg 6.0012+00 5.00E+00
-4.973 4C00E+00 3.OOE+00 2 2.00E+00 0
1.00E+00 0.891 P
0 0
0 "0
0 0
0 0
0 0
0 0
0 0
>a j 400E+00 CD S-2.00E+00 43.00E+00
-3.-91
-4.00E+00
-4.00E+00 5Measurement Locations o=:Activity Ave ra ge -
"+3 StDev"
"-3 StDev
- 0.
(tJ 0*
C) 4C*
F1000002 Frequency Plot Csl 37 DCGL = 51.2 pCi/g 0
t-L.
(I)
..Q0 14 13 12 11 10 9
8 7
6 5
4 3
2 1
0 Iv NT.
x Cý;
N
`5T Bins - Upper End Value (pCi/g)