IR 05000312/1989011
| ML20247A056 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 07/06/1989 |
| From: | Garcia E, Tenbrook W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML20247A051 | List: |
| References | |
| 50-312-89-11, NUDOCS 8907210120 | |
| Download: ML20247A056 (4) | |
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V. S. NUCLEAR REGULATORY COMMISSION
REGION V
Report No. 50-312/89-11 License No. DPR-54 Licensee:
Sacramento Municipal Utility District P. O. Box 15830 Sacramento, California 95813 Facility Name:
Rancho Seco Unit 1 Inspection at:
USNRC Region V Office, Walnut Creek, California Inspection Conducted:
June 29-30, 1989 Inspected by: /ot ~ //
7 - 4 - S' F W. K. Te: Brook, Radiatior. Specialist Date Signed Approved by:
M. kM 7-P /f E. H. Garcia, Acting Chief Date Signed Facilities Radiological Protection Section Summary:
Areas Inspected:
Routine in-office inspection of licensee radiochemical analyses to verify the accurrcy of measurements of radionuclides in release tank water and sediment from the effluent discharge point.
Iitspection procedures 84750 and 92701 were used.
Results:
The licensee's measurements of radionuclides in release tank water and sediment'were confirmed by independent measurements performed by the inspector and the N1C reference laboratcry.
8907210120 890706
PDR ' ADOCK 05000312 Q
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DETAILS
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Persons Contacted
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J. Clark, Manager, Nuclear Chemistry.
R. Mannheimer, Engineer, Nuclear Licensi'ng, R. Orthen, Supervisor, Environmental Noc.;toring.
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'2.
Followup (92701)~
. l jl Followup' Item 50-312/89-03-01-(Closed):
This. item concerned the verification of licensee radiological measurements of sediment from the '
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effluent discharge point.
The inspector nad obtained one liter of wet
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sediment collected by'the licensee during an onsite inspection.
The-sediment was weighed wet, the NRC detector ^ system efficiency for the sediment was datermined, and the specific activity of the sediment was~
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are presented in Table 1.
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Table'1 Sediment from Effluent Discharge Point Nuclide NRC pC1/kg NRC Uncertainty Licensee pCi/kg Licensee /NRC. Range
. l Co-60'
140
148 1.06 0.60-1.66 Cs-134.
211
183 0.87'
O.60-1.66 Cs-137 1600
1620 1.01 0.80-1.25
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The licensee's measurements compared well with the NRC measurements.
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Followup Items 50-312/87-43-01 (Closed); 50-312/89-03-02 - (Closed): - Thi s item concerned the verification of the licensee's measurements _of-radiostrontium and tritium in regenerative hold-up tank.(RHUT); water to supplement onsite' gamma isotopic activity comparisons.
Splits of RHUT water were'obtained by the licenses and the inspector'and were: analyzed
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The comparison of NRC and licensee f
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results is given in Table 2.
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Table 2
Regenerative Hold-Up Tank Water Nuclide NRC:uCi/ml. NRC. Uncertainty Licensee uCi/m1 Licensee /NRC Range
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O.11E-5-7.68E-5" 1.19 0.80-1.25
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'3 Sr-89-1.2 E-8 1. 2 ' E-8 ' 4
< 6.01E-10
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Sr-904 l1.3 E-9 N 3.3 E-9
< 4.15E 10
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i The~ tritium measurements agreed.
NRC and licensee radiostrontium measurements were indistinguishable from radiological background when performed at sensitivities meeting technical specification Table 4.21-2 lower limits of.dv+.ection.
3.
Exit Meeting The inspector _ discussed the results of the intercomparisons with licensee representati.ves noted in section 1 on July 5,1989.
The inspector informed'the licensee that the accuracy of their measurements was confirmed and that the followup items were closed.
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Enclosure Criteria for Accepting the Licensee's Measurements
, Resolution Ratio-
<4 No comparison
7 0.5 2. 0
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15 0.6 1,66
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50 0.75 -
1.33
200 0.80 -
1.25
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200 0.85 -
1.18 i
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Comparison
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Divide each NRC result by its associated uncertainty to obtain the resciution.
(Note:
For purposes of this procedure, the uncertainty is defined as the relative standard deviation, one sigma, of the NRC result as calculated from counting statistics.)
2.
Divide each licensee result by the corresponding NRC result to obtain the ratio (licensee result /NRC).
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The licensee's measurement is in agreement if the value of the ratio
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falls within the limits shown in the preceding table for the corresponding resolution.
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