ML090900774
| ML090900774 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 06/04/2008 |
| From: | Frank G Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| Shared Package | |
| ML090830613 | List:
|
| References | |
| DPG 09-097 | |
| Download: ML090900774 (27) | |
Text
Rancho Seco Final Status Survey Summary Report June 4, 2008 Trench I Eastern Portion Survey Unit F8100051 Prepared By:
Date:
FSS Engineer Reviewed By.:.o*
1~i Date:
'A (0c Lead FSS Engineer Approved By: 1<
Date:
Dismantlement Superintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit:
F8100051, Trench 1 Eastern Portion 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.
The area covered in this portion of Trench 1 is adjacent to the solidification pad and the reactor building equipment hatch and extends 10 meters north of the equipment hatch.
Site Characterization: Soil samples were collected in the area of the survey on the surface 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 0.0469 pCi/g and a maximum value of 0.517 pCi/g. Based on the classification procedure (DSIP-0020) and levels of Cs-137 reported, the area was determined to be a Class 3 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 randomly determined and 750 m2 were scanned for approximately 100%
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 9 FSS Summary Report F8100051
Table 1. Survey Unit Design Parameters Survey Design Parameter Value Comment Survey Area:
F810 Trench 1 Eastern Portion Survey Unit:
0051 Open Land Area Class:
3 LTP Table 5-4 SU Area (m2):
750 Evaluator:
Gary Frank DCGL for Cs-137 surrogate (pCi/g):
52.6 DCGL for Co-60 (pCi/g):
12.6 Area Factor:
N/A Class 3 Design DCGLemc (pCi/g):
N/A Class 3 LBGR (pCi/g):
26.3 Default = 50% Cs-137 DCGL Design Sigma (pCi/g):
0.095 DTBD-06-001, Table 5-4A or B Type I Error:
0.05 Type II Error:
0.05 Sample Area (M2):
N/A Class 3 Total Area Scanned (m2):
750 Scan Coverage (%):
100%
Class 3 Zi., :
1.645 ZI-0 :
1.645 Sign P:
0.99865 Calculated Relative Shift:
276.8 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:
N/A Class 3 Page 3 of 9 FSS Summary Report F8100051
Survey Results:
A total of 67 direct measurements were made in F8100051. 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. Soil samples were counted to the MDCs shown in Table 2-1 of Attachment 2. None of the particle scan measurements indicated areas of elevated activity with a range of 3987 to 10367 cpm below the investigation setpoint of 10443 cpm.. Structures (Solidification Pad wall and wall under the Reactor Building Equipment Hatch) were exposed during the removal of piping and were beta scanned, beta directs were obtained and smears. Scan activity ranged from 4071 to 6844 dpm/100cm2, based on a surveyor efficiency of 0.5 and no background subtracted. The highest Beta Direct measurement is 2837 dpm/100cm 2.
Samples for removable surface activity were less than 10% of the DCGL for beta and alpha activity was below MDC shown in Table 2-1 of Attachment 2.
Penetrations into Pump Alley were performed with this survey to allow the grouting of the penetrations in order to minimize water incursion into the Auxiliary Building. Scan activity ranged from 5300 to 9353 dpm/100cm2, based on a surveyor efficiency of 0.5 and no background subtracted. Samples for removable surface activity were less than 10% of the DCGL for beta and alpha activity was below MDC shown in Table 2-1 of.
Page 4 of 9 FSS Summary Report F8100051
Table 2-1. Direct Measurement Results (all activity values in pCi/g)
Cs 137 Co6O Sample ID MDA Activity Uncertainty Unity MDA Activity Uncertainty Unity Unity Value Value Total F8100051SOOOISS 3.86E-02
<3.86E-02 0.0007 5.64E-02
<5.64E-02 0.0045 0.0052 F8100051S0002SS 5.37E-02
<5.37E-02 0.001 4.OOE-02
<4.OOE-02 0.0032 0.0042 F8100051SO003SS 4.29E-02
<4.29E-02 0.0008 4.81E-02
<4.81E-02 0.0038 0.0046 F8100051SO004SS 4.57E-02
<4.57E-02 0.0009 3.94E-02
<3.94E-02 0.0031 0.004 F8100051SO005SS 4.98E-02
<4.98E-02 0.0009 5.69E-02
<5.69E-02 0.0045 0.0055 F8100051SO006SS 4.53E-02
<4.53E-02 0.0009 3.64E-02
<3.64E-02 0.0029 0.0037 F8100051S0007SS 5.16E-02
<5.16E-02 0.001 4.06E-02
<4.06E-02 0.0032 0.0042 F8100051S0008SS 5.17E-02
<5.17E-02 0.001 5.79E-02
<5.79E-02 0.0046 0.0056 F8100051SO009SS 4.32E-02
<4.32E-02 0.0008 5.27E-02
<5.27E-02 0.0042 0.005 F8100051SOO1OSS 5.95E-02
<5.95E-02 0.0011 9.39E-02
<9.39E-02 0.0075 0.0086 F8100051SO01I1SS 6.85E-02
<6.85E-02 0.0013 4.62E-02
<4.62E-02 0.0037 0.005 F8100051SO012SS 5.20E-02
<5.20E-02 0.001 5.40E-02
<5.40E-02 0.0043 0.0053 F8100051SO013SS 4.05E-02
<4.05E-02 0.0008 4.13E-02
<4.13E-02 0.0033 0.004 F8100051S0014SS 4.11E-02
<4.11E-02 0.0008 5.46E-02
<5.46E-02 0.0043 0.0051 F8100051SO015SS 4.19E-02
<4.19E-02 0.0008 2.90E-02
<2.90E-02 0.0023 0.0031 F8100051S0016SS 5.62E-02
<5.62E-02 0.0011 4.81E-02
<4.81E-02 0.0038 0.0049 F810005lSO017SS 5.11E-02
<5.11E-02 0.001 5.02E-02
<5.02E-02 0.004 0.005 F8100051SO018SS 4.09E-02
<4.09E-02 0.0008 5.51E-02
<5.51E-02 0.0044 0.0052 F8100051SO019SS 5.OOE-02
<5.OOE-02 0.001 4.58E-02
<4.58E-02 0.0036 0.0046 F8100051SO02OSS 4.38E-02
<4.38E-02 0.0008 4.70E-02
<4.70E-02 0.0037 0.0046 F8100051SO021SS 4.42E-02
<4.42E-02 0.0008 4.58E-02
<4.58E-02 0.0036 0.0045 F8100051S0022SS 4.84E-02
<4.84E-02 0.0009 5.31E-02
<5.31E-02 0.0042 0.0051 F8100051SO023SS 4.64E-02
<4.64E-02 0.0009 4.54E-02
<4.54E-02 0.0036 0.0045 F8100051SO024SS 4.2 1 E-02
<4.21E-02 0.0008 -*
4.62E-02
<4.62E-02 0.0037 0.0045 F8100051SO025SS 4.44E-02
<4.44E-02 0.0008 4.14E-02
<4.14E-02 0.0033 0.0041 F8100051S0026SS 4.57E-02
<4.57E-02 0.0009 3.61E-02
<3.61E-02 0.0029 0.0037 F8100051S0027SS 3.76E-02
<3.76E-02 0.0007 5.57E-02
<5.57E-02 0.0044 0.0051 F8100051SO028SS 4.56E-02
<4.56E-02 0.0009 3.52E-02
<3.52E-02 0.0028 0.0037 F8100051SO029SS 4.93E-02
<4.93E-02 0.0009 4.55E-02
<4.55E-02 0.0036 0.0045 F8100051SO03OSS 4.43E-02
<4.43E-02 0.0008 3.42E-02
<3.42E-02 0.0027 0.0036 F8100051SO031SS 5.65E-02
<5.65E-02 0.0011 4.86E-02 1.18E-01 5.51E-02 0.0094 0.0105 Page 5 of 9 FSS Summary Report F8100051
F8100051SO032SS 4.49E-02 1.33E-01 4.08E-02 0.0025 4.94E-02 4.46E-0t 5.65E-02 0.0354 0.0379 F8100051S0033SS 5.10E-02 4.03E-01 7.87E-02 0.0077 4.34E-02 7.71E-01 1.13E-01 0.0612 0.0688 F8100051S0034SS 4.37E-02
<4.37E-02 0.0008 5.30E-02
<5.30E-02 0.0042 0.005 F8100051SO035SS 4.65E-02
<4.65E-02 0.0009 6.52E-02
<6.52E-02 0.0052 0.0061 F8100051SO036SS 3.19E-02
<3.19E-02 0.0006 3.11E-02
<3.11E-02 0.0025 0.0031 F8100051S0037SS 3.91E-02
<3.91E-02 0.0007 3.60E-02
<3.60E-02 0.0029 0.0036 F8100051SO038SS 3.30E-02
<3.30E-02 0.0006 3.74E-02
<3.74E-02 0.003 0.0036 F8100051SO039SS 4.36E-02
<4-36E-02 2.18E-02 0.0008 2.42E-02
<2.42E-02
.0.0019 0.0027 F8100051SO04OSS 4.90E-02
<4.90E-02 0.0009 4.60E-02
<4.60E-02 0.0037 0.0046 F8100051SO04ISS 3.22E-02
<3.22E-02 0.0006 3.85E-02
<3.85E-02 0.0031 0.0037 F8100051 S0042SS 4.14E-02
<4.14E-02 2.22E-02 0.0008 4.20E-02
<4.20E-02 0.0033 0.0041 F8100051S0043SS 4.40E-02
<4.40E-02 0.0008 3.90E-02
<3.90E-02 0.0031 0.0039 F8100051S0044SS 4.74E-02
<4.74E&02 0.0009 3.52E-02
<3.52E-02 0.0028 0.0037 F8100051S0045SS 4.39E-02
<4.39E-02 0.0008 3.87E-02
<3.87E-02 0.0031 0.0039 F8100051S0046SS 4.44E-02
<4.44E-02 0.0008 3.78E-02
<3.78E-02 0.003 0.0038 F8100051S0047SS 4.35E-02
<4.35E-02 0.0008 4.25E-02
<4.25E-02 0.0034 0.0042 F8100051S0048SS 3.63E-02
<3.63E-02 0.0007 4.75E-02
<4.75E-02 0.0038 0.0045 F8100051S0049SS 4.69E-02
<4.69E-02 0.0009 4.76E-02
<4.76E-02 0.0038 0.0047 F8100051SO05OSS 4.51E-02
<4.51E-02 0.0009 4.09E-02
<4.09E-02 0.0032 0.0041 F8100051SO05ISS 3.77E-02
<3.77E-02 0.0007 4.58E-02
<4.58E-02 0.0036 0.0044 F8100051S0052SS 4.15E-02
<4.15E-02 0.0008 4.07E-02
<4.07E-02 0.0032 0.004 F8100051SO053SS 4.51E-02
<4.51E-02 0.0009 5.43E-02
<5.43E-02 0.0043 0.0052 F8100051SO054SS 4.25E-02
<4.25E-02 0.0008 4.55E-02
<4.55E-02 0.0036 0.0044 F8100051S0055SS 3.61E-02
<3.61E-02 0.0007 4.36E-02
<4.36E-02 0.0035 0.0041 F8100051S0056SS 4.54E-02
<4.54E-02 0.0009 5.22E-02
<5.22E-02 0.0041 0.005 F8100051S0057SS 2.47E-02
<2.47E-02 0.0005 4.68E-02
<4.68E-02 0.0037 0.0042 F8100051S0058SS 3.45E-02
<3.45E-02 0.0007 4.45E-02
<4.45E-02 0.0035 0.0042 F8100051S0059SS 4.67E-02
<4.67E-02 0.0009 5.22E-02
<5.22E-02 0.0041 0.005 F8100051SO06OSS 4.19E-02
<4.19E-02 0.0008 4.65E-02
<4.65E-02 0.0037 0.0045 F8100051SO061SS 4.42E-02
<4.42E-02 0.0008 3.37E-02
<3.37E-02 0.0027 0.0035 F8100051S0062SS 4.07E-02
<4.07E-02 0.0008 4.07E-02
<4.07E-02 0.0032 0.004 F8100051S0063SS 4.80E-02
<4.80E-02 0.0009 6.55E-02
<6.55E-02 0.0052 0.0061 F8100051S0064SS 5.61E-02
<5.61E-02 0.0011 5.57E-02
<5.57E-02 5.15E-02 0.0044 0.0055 F8100051S0065SS 4.21E-02
<4.21E-02 0.0008 3.45E-02
<3.45E-02 0.0027 0.0035 F8100051SO066SS 6.29E-02
<6.29E-02 0.0012 4.21E-02
<4.21E-02 0.0033 0.0045 F8100051SO067SS 4.83E-02
<4.83E-02 0.0009 5.03E-02
<5.03E-02 0.004 0.0049 Page 6 of 9 FSS Summary Report F8100051
Table 2-2. Direct Measurements Results Summary Cs137 Co60 Activity Activity Cs137 Unity Co60 Unity Unity Total (p Ci/g)
(pCi/g)
DCGLw 52.6 12.6.
Mean 5.16E-02 6.36E-02 0.001 0.0051 0.006 Median 4.44E-02 4.58E-02 0.0008 0.0036 0.0045 Standard Dvain 4.54E-02, 1.0E-01 0.0009 0,008 0.0089 DeviationI Cs137 Activity Range (pCi/g) 2.47E-02 to 4.03E-01 Co60 Activity Range (pCi/g) 2.42E-02 to 7.71 E-0 I Cs137 Unity Range 0.0005 to 0.0077 Co60 Unity Range 0.0019 to 0.0612 Total Unity Range 0.0027 to 0.0688 Sample Count 67 Survey Unit Data Assessment:
The survey design required 67 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 7 of 9 FSS Summary Report F810005!1
Table 3. Data Assessment Results Survey Results Parameter Value Comment Actual Direct Measurements (N):
67 Median (Unity):
0.004 Mean (Unity):
0.006 Direct Measurement Std Deviation (unity):
0.009 Maximum (Unity):
0.069 Sign Test Final N Value:
67 S+ Value:
67 Critical Value:
40 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 3 Standard Deviation <= Sigma:
Yes All Values <0.5 DCGL Pass the Sign Test?
Yes Reject the Null Hypothesis?
Yes Does the Survey Unit Pass All Criteria?
Yes Survey Unit Passes Page 8 of 9 FSS Summary Report F8100051
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, the ALARA criterion has been met.
Changes in Initial Survey Unit Assumptions:
The survey unit was designed as a Class 3 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. No potential areas of elevated activity were detected.
==
Conclusion:==
The FSS of this survey unit was properly designed as a Class 3 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 F8100051 meets the release criteria of IOCFR20.1402.
Page 9 of 9 FSS Summary Report F8100051 Maps June 4, 2008 Survey Unit F8100051 C,
F8100051 Trench 1 Eastern Portion Original condition Edge of Solidification Pad Page 1 Paae 2 of I I zD Att. I Maps F8100051
F8100051 Trench 1 Eastern Portion Obtaining soil samples Survey of concrete surface prior to penetrations into Pump Alley Page 2 grouting Page 3 of I11 Att. I Maps F8100051
F8100051 Trench 1 Eastern Portion Grouting of penetrations into Pump Alley Survey of penetrations from Pump Alley Soil sample locations on spoils pile
- Page 3 Paoe 4 of I I ZD Att. 1 Maps F8100051
(:
F8100051 Trench 1 Eastern Portion
)btaining soil samples ing and securing pipe ends Preparing for another cut Preparing a section of pipE for removal Page 4 Survey Page 5 of I I Att. 1 Maps F8100051
F8100051 Trench 1 Eastern Portion Ends of the pipes are secured and the ground below the drip pan is sampled Much of the soil removal is accomplished by hand due to the proximity of the pipes.
,ULury L[IU.PIP, *U(;LiUII ruquIIU capture of the lubricant and shavings into a lined drip pan.
Page 5 Page 6 of I I Att. 1 Maps F8100051
F8100051 Trench 1 Eastern Portion noval of abandoned water lines Gamma scan areas and soil sample marked with flags (noted with circle)
Beta scans on Solidification Pad wall looking south Page 6 Page 7 of 11 Att. I Maps F8100051
F8100051 Trench 1 Eastern Portion II
-U Page 7 Page 8 of 11 Att. 1 Maps F8100051
F8100051 Trench 1 Eastern Portion Beta scans below the RX Bldg Equipment Hatch Page 8 Page 9 of 11 Att. I Maps F8100051
F8100051 Trench 1 Eastern Portion "A
Page 9 Page 10 of 11 Att. I Maps F8100051
F8100051 Trench 1 Eastern Portion The open trench was backfilled and the soil compacted in preparation for the removal of the internal concrete of the reactor building.
After the completion of the reactor building concrete/polar crane removal the area will be resurveyed as part of the tank farm land survey.
Page 10 Page 11 of 11 Att. I Maps F8100051 Instrumentation June 4, 2008 Survey Unit F8100051
Table 2-1. Survey Unit Instrumentation I nstrument Detector Detector Serial MDC Model No.
No.
HPGe GC2820 9987008 Soil - 0.3 pCi/g Cs-137 HPGe GC3020 05047773 Soil - 0.3 pCi/g Cs-137 Tennelec N/A 0401171 6 dpm cx, 12 dpmI3 433 dpm/100cm 2 Static, 1033 2350-1, 180738 43-68B 148633 dpm/100cm 2 Scan 433 dpm/100cm2 Static, 1033 2350-1, 193700 43-68B 190294 dpm/1OOcm 2 Scan 433 dpm/100cm 2 Static, 1033 2350-1, 203481 43-68B 148629 dpm/100cm 2 Scan 2350-1, 193700 SPA-3 404397 5.2 pCi/g Scan 2350-1,203482 44-10 211672 5.2 pCi/g Scan 2350-1, 142509 44-159 238370 5250 dpm/lOOcm 2 Static Table 2-2. Investigation Criteria and DCGL Instrument Parameter Value nCriteria Soil - 25.6 pCi/g Cs-137 Soil - 6.3 pCi/g Co-60 43-68B Investigation Criteria 2910 cpm Scan, 4150 cpm Static SPA-3/44-10 Investigation Criteria 10443 cpm Scan 44-159 Investigation Criteria 1200 cpm Scan All DCGLw 52.6 Cs-137 12.6 Co-60 Design DCGLEMC from Table 1 of FSS All DCGLEMC Summary Report or from DQA Evaluation Summary Page 2 of 2 Att. 2 Instrumentation F8100051 Investigation June 4, 2008 Survey Unit F8100051 (none required)
Data Assessment June 4, 2008 Survey Unit F8100051
I A
(D~
Cn WJ (D~
00 F8100051 Quantile Plot N
0.080 0.070 0.060 0.050 0.040 0.030 0.020 0.010 0.000 0.004 100
]
0 20 40 60 Percentile 80 Unitized Total Value -Median
- - 75th Percentile -
- 50th Percentile
00 C)
F8100051 Scatter Plot 0.080 0.070 0.060 0.050 0,040 0-0.030
. 0.03 0.020-
_.N 0.020 0
C 0 1 0 0.000
-0.010
-0.020
-0.021
-0.030 Measurement Locations o
Unitized Total Value -
- Averaqe - - -"+3StDev - -
=-3StDev-
'Ut 00 C),
F8100051_ Frequency Plot
"-1 c-0 Bins - Upper. End Value (Unitized Total)