ML081610114
| ML081610114 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 03/18/2008 |
| From: | Donna Anderson Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| References | |
| F1000003 | |
| Download: ML081610114 (20) | |
Text
Rancho Seco Final Status SurveySummary Report March 18, 2008 Plant Effluent Water Course (SU3)
Survey Unit F1000003 Prepared By:
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Date:
3/is/-c FSS En cieer Reviewed By:
Date: */
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Lead FSEngineer Approved By:....
0Date:
7 Dismantlement perintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit:
F 1000003, Plant Effluent Water Course (SU3)
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 1,180 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 8 FSS Summary Report F1000003
Table 1. Survey Unit Design Parameters Survey Design Parameter Value Comment Survey Area:
F100 Plant Effluent Water Course (SU3)
Survey Unit:
0003 Open Land Area Class:
2 LTP Table 5-4 SU Area (m2):
5,202 F8000071 Evaluator:
D. Anderson DCGL for Cs-137 surrogate (pCi/g):
52.6 DCGL for Co-60 (pCi/g):
12.6 Area Factor:
N/A Class 2 Design DCGLemc (pCi/g):
N/A Class 2 LBGR (pCi/g):
27.8 Adjusted Design Sigma (pCi/g):
/
14.7 DTBD-06-001, Table 5-4A or B Type I Error:
0.05 Type II Error:
0.05 Sample Area (m2):
306 Class 2 Total Area Scanned (m2):
1,180 Scan Coverage (%):
22.7%
Class 2 Zl-,
1.645 ZI_:
1.645 Sign P:
0.945201 Calculated Relative Shift:
1.6 Relative Shift Used:
1.6 Uses 3.0 if Rel Shift >3 N-Value:
14 Design N-Value + 20%:
17 NUREG-1575 Table 5-5 Grid Spacing L:
17.5 Class 2 Page 3 of 8 FSS Summary Report F1000003
Survey Results:
A total of 21 direct measurements were made in F 1000003. 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. None of the scan measurements indicated areas of elevated activity. Soil samples were counted to the MDCs shown in Table 2-1 of Attachment 2.
Page 4 of 8 FSS Summary Report F1000003
Table 2-1. Direct Measurement Results (all activity values in pCi/g)
V
<9.46E-02 0.0075 0.0104 F1000003S0002SS 8.17E-02 2.01E-01 7.72E-02 0.0038 8.76E-02
<8.76E-02 0.007 0.0108 F1000003SO003SS 6.48E-02 1.29E-01 6.41E-02 0.0024 1.02E-01
<1.02E-01 0.0081 0.0105 F1000003SO004SS 9.86E-02 1.90E00 1.86E-01 0.0361 7.61E-02
<7.61E-02 0.006 0.0421 F1000003S0005SS 8.16E-02 1.50E00 1.93E-01 0.0285 1.12E-01
<1.12E-01 0.0089 0.0374 F1000003SO006SS 7.67E-02 8.25E-01 1.34E-01 0.0157 6.94E-02
<6.94E-02 0.0055 0.0212 F1000003SO007SS 6.44E-02 1.09E-01 4.84E-02 0.0021 1.05E-02
<1.05E-02 0.0008 0.0029 F1000003S0008SS 9.03E-02 3.50E-01 8.72E-02 0.0067 6.68E-02
<6.68E-02 0.0053 0.012 F1000003SO009SS 5.41E-02 2.32E-01 7.27E-02 0.0044 3.80E-02
<3.80E-02 0.003 0.0074 F1000003SOO1OSS 1.12E-01 2.23E01 1.53E00 0.4234 6.19E-02 1.92E-01 6.93E-02 0.0153 0.4386 F1000003SO01ISS 6.75E-02 2.56E-01 6.50E-02 0.0049 6.44E-02
<6.44E-02 0.0051 0.01 F1000003SO012SS 6.37E-02 8.95E-02 7.04E-02 0.0017 6.79E-02
<6.79E-02 0.0054 0.0071 F1000003SOO13SS 5.67E-02 5.19E-01 9.78E-02 0.0099 5.97E-02
<5.97E-02 0.0047 0.0146 F1000003SO014SS 6.43E-02
<6.43E-02 0.0012 7.39E-02
<7.39E-02 0.0059 0.0071 F1000003S0015SS 9.30E-02
<9.30E-02 0.0018 6.30E-02
<6.30E-02 0.005 0.0068 F1000003S0016SS 5.16E-02 6.58E-02 6.78E-02 0.0013 9.05E-02
<9.05E-02 0.0072 0.0084 F1000003S0017SS 8.29E-02
<8.29E-02 0.0016 7.40E-02
<7.40E-02 0.0059 0.0074 F1000003SO018SS 5.61 E-02
<5.61E-02 0.0011 7.15E-02
<7.15E-02 0.0057 0.0067 F1000003SO019SS 7.67E-02 1.04E-01 3.80E-02 0.002 6.12E-02
<6.12E-02 0.0049
- 0.0068 F1000003SO02OSS 7.35E-02
<7.35E-02 0.0014 6.08E-02
<6.08E-02 0.0048 0.0062 F1000003SO021SS 9.45E-02
<9.45E-02 0.0018 7.50E-02
<7.5OE-02 0.006
. 0.0077 Page 5 of 8 FSS Summary Report F1000003
Table 2-2. Direct Measurements Results Summary C
Cs137 Co60 Activity Activity Cs137 Unity Co60 Unity Unity Total (pCi/g)
(pCi/g)
DCGLw 52.6 12.6 jf Mean 1.39E00 7.67E-02 0.0264 0.0061 0.0325 Median 1.29E-01 7.15E-02 0.0024 0.0057 0.0084 Standard 4.81E00 3.40E-02 0.0914 0.0027 0.0936 Deviation Cs137 Activity Range (pCi/g) 5.61E-02 to 2.23E01 Co60 Activity Range (pCi/g) 1.05E-02 to 1.92E-01 Cs137 Unity Range 0.0011 to 0.4234 Co60 Unity Range 0.0008 to 0.0153 Total Unity Range 0.0029 to 0.4386 Sample Count 21 Survey Unit Data Assessment:
The survey design required 21 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 F1000003
Table 3. Data Assessment Results Survey Results Parameter Value Comment Actual Direct Measurements (N):
21 Median (Unity):
0.008 Mean (Unity):
0.032 Direct Measurement Std Deviation (Unity):
0.094 Maximum (unity):
0.439 Sign Test Final N Value:
21 S+ Value:
21 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):
N/A Class 2 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 F1000003
Survey Unit Investigations and Results:
No i'nvestigations 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 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 Unity. 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 F 1000003 meets the release criteria of 10CFR20.1402.
Page 8 of 8 FSS Summary Report F1000003 Maps March 18, 2008 Survey UnitF1000003
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FI0000 Smuo UT~~LFILFFY DIS'TRICTFSLCTIN F
[D PLANT EFFLUENT WATER COURSE
'--6B I236DE 1887774N 681z137E 18875811N 6811)17E 1887340N 6811065N 1887335E MAP F1000003-1, SURVEY AREA CONFIGURATION 1 TOTAL SIZE OF SURVEY AREA: 21,285 SQ M SCALE METERS I-w"
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SMUD SACRAMENTO UNICIPAL FSS LOCATION:
F1000003 PLANT EFFLUENT WATER COURSE (SU3) o 1 0 15 20 25 SCALE METERS RANDOM START POINT-6B0I871E.
1887306N
. MAP F1000003-2, SOIL LOCATIONS (DIRECT MEASUREMENTS)
F1O000S00JSOO1 SS-F10000035002155 SOIL SAMPLES 10MIM
(D 0.
o' SMUD SUTILMENTO MUDCPAL FSS LOCATION:
F1000003 PLANT EFFLUENT WATER COURSE (SU3)
N 0 5 10 15 20 25 SCALE METERS
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49 14 4
- 4
- 4
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.4 Ik Ia iSoCS FIELD OF VIEV, 28 mz ON 5 METER CENTERS MAP F1DOD03-3, GAMMA SCANS Fl 00000350001(GS-F1 00000350043GS TOTAL SCAN AREA:
1023 SQ METERS
l'b SMUD
~SACRAi, "ETouTLT "I'RcMN"CA' FSS LOCATION:
Fl000003 PLANT EFFLUENT WATER COURSE (SU3)
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Instrumentation March 18, 2008 Survey Unit F100000 3
Table 2-1. Survey Unit Instrumentation Detector Detector Serial Instrument Model MDC NO.No.
HPGe N/A 9987008 Soil-1.12E-01 pCi/g Cs-137 Soil-1.12E-01 pCi/g Co-60 HPGe N/A 05047773 Soil - 9.86E-02 pCi/g Cs-137 Soil - 8.76E-02 pCi/g Co-60 ISOCS N/A 2983947 Soil - 2.98E-01 pCi/g Cs-137 Soil - 2.45E-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 All DCGLw 52.6 Cs-137 12.6 Co-60 All DCGLEMC N/A Page 2 of 2 Att. 2 Instrumentation F1000003 Investigation March 18, 2008 Survey Unit F1000003 (none required)
Data Assessment March 18, 2008 Survey Unit F1000003
SF1000003 Quantile Plot
[0 4C
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0.500 0.450 0.400 0.350
.-t N
C:
0.300 0.250 0.200 0.150 0.100 0.050 0.000 0.008 0
20 40 60 80 100 Percentile I*
Unitized Total Value -
Median -
- - 75th Percentile - - -
- 50th Percentile I
Pt pa 0
F1 000003 Scatter Plot CD3 CD a:
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N Cn 0.500 0.400, 0.300 0.200 0.100 0.000
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A.-d 10.313 0.032
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Measurement Locations SUniize Total Value -
-Average --
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- -"-3StDev"i
F1000003 Frequency Plot
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