IR 05000275/1988033
| ML16341E953 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 12/27/1988 |
| From: | North H, Tenbrook W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML16341E952 | List: |
| References | |
| 50-275-88-33, 50-323-88-31, NUDOCS 8901180214 | |
| Download: ML16341E953 (8) | |
Text
U.
S.
NUCLEAR REGULATORY COHHISSION REGION V
Report Nos.
50-275/88-33, 50-323/88-31 License Nos.
OPR-80, DPR-82 Licensee:
Pacific Gas and Electric 77 Beale Street, Suite 1451 San Francisco, California 94106 Facility Name:
Diablo Canyon Power Plant, Units 1 and
Inspection at:
USNRC Region V, Walnut Creek, California Inspection Conducted:
December 19-20, 1988 Inspected by:
M.
K. TenBroo
, Radiation Specialist Approved by:
H.
S. North, Acting Chief Facilities Radiological Protection Section r~ c~
PJ'ate Signed r> t.y PP
~
Da e igned
~Susea f
by the licensee for measurement intercoaparison.
Inspection procedure 92701 was Used.
Results:
The licensee's analysis or a radiocheaical test saaple indicated a
satisfactory aeasureaent capability ror aost saapla radionuclides.
However, disagreement was observed for Sr 90 analyses.
The safety significance of the measurement disagreement was low due to the small fraction of Sr-90 present in waste processes and effluent.
The inspector will conduct an intercomparison for Sr-90 in plant liquid effluent during a future inspection.
8901180214 881228 PDR ADOCK 05000275
DETAILS 1.
Persons Contacted D. Unger, Radiochemical Engineer 0 en Item 50-275/87-17-01 CLOSED This item concerned disagreements between licensee and NRC measurements of Fe-55 in an Nlg intercomparison test sample.
The 'Iicensee had suggested that certain data were transposed in the data report, resulting in a poor intercomparison.
The inspector arranged to send an additional radiochemical test sample to the licensee for intercomparison.
The results of the gamma analysis of the second intercomparison test are given in Table 1.
The NRC evaluation criteria are explained in the enclosure.
Table
Gamma Isotopic Measurements of NRC Capability Test Sample Ratio:
Licensee/NRC Detector 85 Detector f6 Nuclide NRC uCIiml Trial 1 Tcial
Trial 1 Teial
~Ran e
Cs-134 Cs-137 Mn-54 Zn-65 Co-60 (5. 39 2 0. 22)E-6 (5.24 ~ O.16)E-6 (1.O7 ~ O.O4)E-6 (5.26 2 0.21)E-6 (2.62 i 0.08)E-6 0. 86 D.96 0. 95 0. 97 0. 91 0. 88 0. 94 0. 95 l. 02 0. 95 l. OD 0. 89 1. 02 0.90 0. 93 0. 94 1. 03 0. 98 l. 04 0. 94 0.75-1.33 0. 75"1. 33 0. 75"1. 33 0. 75"1. 33 0. 75-1. 33 The licensee's gama analysis was in agreement with the certified values.
The results of analyses for pure beta and x-ray emitters are presented in Table 2.
Nuclide Table 2 arison of Beta and X-Ray Emitters Ratio:
Licensee/NRC Trial 1 Trial 2
~Ran e
H-3 Fe"55 Sr-89 Sr"90 (l. 64 i 0. 03) E"5 (1.62 i 0.03)E-5 (1.24 2 0.04)E-4
.(7.47 L 0.30)E-6 0. 87 0. 94 0. 87 0. 69 0. 92 0. 68 The licensee results for Fe-55 were within the agreement 50-375/87-17-01 is considered closed.
0. 80-1. 25 0.80-1.25 0. 75-1. 33 0.75-1.33 range.
Item
The licensee results for the Sr-90 analyses did not agree with the NRC certificate value for spiked activity, while the two licensee results were mutually consistent.
Exit Meetin The inspector and the cognizant radiochemist discussed the intercomparison results on Oecember 20, 1988.
The yttrium carrier, used to determine Sr-90, was discussed as a possible common source of systematic error in the licensee strontium analyses.
It was agreed that the licensee would prepare a new yttrium carrier solution as a
precaution.
Also, the licensee and the inspector agreed that an internal Sr-90 spiked sample would be analyzed with future strontium analyses as a
quality control check.
The inspector informed the Licensee that a
suitable plant process liquid sample for would be obtained during a
future inspection for independent analyses as required by technical specification 4. 11. 1. 1, including Sr-90 analysis (50-275/88-33-01).
Enclosure Criteria for hcce tin the Licensee's Measurements Resolution Ratio
<4
~
8 -
16 -
51
- 200 200 0.4
-
2.5 0.5
-
2.0 0.6
-
1.66 0.75 1.33 0.80
-
1.25 0.85
-
1.18 Co arison Divide each NRC result by. its associated uncertainty to obtain the-resolution.
(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).
3o The licensee's measurement is in agreement if the value of the ratio
,
falls within the limits shorn in the preceding table for the corresponding resolutio