IR 05000306/1981006
| ML19347F708 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/10/1981 |
| From: | Hopkins J, Jackiw I, Robinson D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19347F706 | List: |
| References | |
| 50-306-81-06, 50-306-81-6, NUDOCS 8105260091 | |
| Download: ML19347F708 (10) | |
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U.S.. NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Report-No. 50-306/81-06 Docket No. 50-306 License No. DPR-60 Licensee: -Northern States Power Company
'414 Nicollet Mall Minneapolis, MN 55401
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Facility Name: Prairie Island Nuclear Generating Plant Unit 2 Inspection At: Red Wing, MN Inspection Conducted: Marc 25-27, 1981
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Inspectors:
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D. L.
binson
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Accompanying Personnel:
I. N. Jackiw Q'k '/.
iw,ActingChlief Ln eb ll l
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Approved By:
I. N. Ja Test Program Section Inspection Summary Inspection on March 25-27, 1981 (Report No. 50-306/81-06)
Areas Inspected: Routine, announced inspection of the conta4.nment integrated leak rate test. The inspection involved a total of 64 inspector-hours onsite
~ by two NRC inspectors including 16 inspector-hours onsite during offshifts.
Results: No items of noncompliance or deviations were identified.
810526009/
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DETAILS 1.
Persons Contacted F. Tierney, Plant Manager E. Watzl, Plant Superintendent, Plant Engineering and Radiation
. Protection A. Hunstad, Staff Engineer D. Haugland, Engineer R. Fraser, Engineer 2.
Prairie Island Unit 2
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Containment Integrated Leak Rate Test
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a.
Procedure Review
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The inspector reviewed procedure SP-2071, " Integrated Leakage Rate Test," and verified that the procedure was technically ade-quate and consistent with regulatory requirements.
b.
Instrumentation The inspector reviewed the calibration data associated with per-forming the CILRT. A multipoint calibration of all instrumenta-tion was performed. Correction values were generated based on the difference between measurements of resistance from a NBS verified resistance box and actual resistance measured. All corrections were placed as an array or equation into the CILRT computer.
The following instrumentation was used in the CILRT:
Type Quantity Serial Number RTDs
TE 1-24
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Flowmeter
FI-I l
Pressure Gauge
PI-1 & PI-2 Dewcells
ME 1-6 During pressurization, dewcell ME-5 was declared inoperable, resulting in its weighting factor being reassigned to dewcells ME-4 and ME-6.
Also, the F0M (figure of erit) was recalculated.
and met the requirements of FOM $ 0.25 L.
t c.
Witness of Test
l The inspector witnessed portions of the CILRT on March 26-27, 1981, and noted the following:
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Appropriate revision of procedure was in use by test personnel.
Test prerequisites were met.
Proper plant systems were in-service.
-During pressurization, reactor coolant pump seal leakage to the-Rf.JT (reactor coolant drain tank) was discovered. The seal'leaLage-
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was isolated and the RCDT was pumped down.
During the test, the licensee's leak rate measurements'from the'
CDC and Comshare computers-diverged. The cause was found to be
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incorrect times input to the CDC ccmputer program. 1After the problem was corrected, the measurements again agreed with each other.
The induced leakage, Lo, during the supplemental test.was approxi-mately 0.25 Lt.
Since, the acceptance band for the supplemental test is 1 0.25 Lt, the leak rate need only increase slightly to be acceptable for the supplemental test. Proposed standard ANS N274 requires Lo to be between 0.75 Lt and 1.25 Lt. 'This requirement was discussed with licensee representatives during the inspection and in a telephone discussion with the licensee on April 1, 1981.
d.
Direct Observation of Valve Lineups The inspector verified by direct visual observation that valve lineups were completed in accordance with the test procedure.
e.
Blowdown and Containment Inspection The inspector verified that blowdown was within Technical Specifi-cation radioactivity release limits. An independent post CILRT containment inspection was conducted for equipment degradation after blowdown and did not identify any degradation.
f.
CILRT Data Evaluation l
The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> CILRT was started on March 26, 1981, at 1800 hrs. The
inspector independently monitored and evaluated leak rate data to j
verify the licensee's calculation of the leak rate. There was l
acceptable agreement between'the inspector's and licensee's leak l
rate calculations as indicated in the following summary (units are in weight percent per day):
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Measurement Licensee Inspector i
j Leakage rate measured 0.0147 0.0153 (Ltm) during CILRT Ltm at 95% confidence level 0.0206 0.0230-3-
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Appendix J Acceptance Criterio-at 95%' confidence level a
= 0.75 Lt = 0.75 (0.1768%/ day) = 0.1326%/ day. As indicated above, the adjusted Ltm at the 95% confidence level was less than the maximum allowable by 10 CFR Part 50, Appendix J.
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Supplemental Test Data Evaluation After the satisfactory completion of the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test on March-27,
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1981, a known leakage of 0.0493 weight percent / day was induced.
The inspector independently monitored and evaluated leak rate data to verify the licensee's calsulation of the supplemental leak rate.
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There was acceptable agreement between the inspector's and licen-see's leak rate calculations as indicated in the following summary (units are in weight percent per day):
- Measurement Licensee Inspector Measured leakage (Lc) rate
.0501
.073)
during supplemental test Induced leakage rate (lo) = 0.0493 Appendix J Acceptance Criterion: Lo + Ltm. 0.25 Lt <i Lc di Lo + Ltm + 0.25 Lt.
As indicated above, the supplemental test results satisfied the requirements of 10 CFR Part 50, Appendix J.
No items of noncompliance or deviations were identified.
3.
Exit Interview Because the inspection was concluded after working hours on March 27, 1981, the inspector summarized the purpose, scope, and findings of the inspection in a telephone call to Mr. F. Tierney on April 1, 1981.
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