IR 05000282/1990013
| ML20055J047 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 07/24/1990 |
| From: | Gardner R, Neisler J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20055J046 | List: |
| References | |
| 50-282-90-13, 50-306-90-13, NUDOCS 9008010003 | |
| Download: ML20055J047 (4) | |
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U. S. NUCLEAR REGULATORY COMMISSION REGION 111 Reports No. 50-282/90013(DRS);50-306/90013(DRS)
Docket Hos. 50-282; 50-306 Licenses No. DPR 42; No. DPR-60 Licensee: Northern States Power Company 414 Nicollet Mall Minneapolis, MN 55401 Facility Name:
Prairie Island Nuclear Generating Station - Units 1 and 2 Inspection At: Welch, MN 55089 Inspection Conducted: July 9, 11 and 12, 1990 Inspector:
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J. H. Neisler Oate
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Approved By:
R. N. Gardner, cFier Date i
Plant Systems Section inspection Summary
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inspection on July 9,11 and 12,1990 (Reports No. 50-282/90013(DRS);
No. 50-306/90013(DRS))
Areas Inspected:
Routine, unannounced inspection to examine the licensee's construction, inspection and testing activities relative to the Station Blackout / Electrical System Upgrade Modification and followup of previously
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identified inspection issues (92701, 37700, SIMS USI A44).
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Results:
No violations or deviations were identified.
A weakness was identified in the licensee's control of contractor performance regarding the practice of allowing concrete t; become prematurely dry during the curing process.
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DETAILS 1.-
Fersons Contacted Northern States Power Company (NSP)
- G. Goering, General Superintendent, Construction
- J. Brystrzycki, SB0/ESU Project Superintendent Quality Control
- J. Leveille, Licensing J. Maki, Project Engineer, SB0/ESU W. Chaney, Quality Control ins >ector, Civil
- R. Pond, Principle Electrical Engineer, SB0/ESU
- R. Sitek, Quality Assurance
- R. Peterson, Electrical Engineer
- R. O' Bryan, Project Construction Superintendent E. Burke, EQ Coordinator-K. Beadel, Superintendent, Technical Engineering Fluor-Daniel
- B. Stuart, Civil Structural Engineer Nuclear Regulatory Commission (NRC)
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- P. Hartmann, Senior Resident inspector
- B. Burgess, Chief, Reactor Projects Section 2A
- Denotes those attending the exit interview conducted'on July 12, 1990.
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Licensee Action on Previously Identified items.
(Closed) Unresolveditem(282/86012-01;306/86014-01): Various discresancies in Raychem splice installation. The inspector verified-that tie Roychem splices have been inspected using the criteria from their equipment qualification (EQ) manual.
Unacceptable splices were.
replaced with new splices that conform to Raycherr cceptance criteria.
This item is considered to be resolved.
(Closed) Unresolveditem(282/86012-01;306/86014-02):
Eleven Limitorque i
valve actuators found installed in unqualified configurations - plastic
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grease caps not removed. The EQ inspectors had questioned whether the grease in the gear case would extrude.into the-limit switch and motor compartments because of temperature increases in the gear cases during peak accident temperatures.
The inspector reviewed Calculation No.
0910-215-Al-The calculation showed that the elevated temperatures experienced during and subsequent to accident scenarios would not cause the grease to expand into the limit switch or motor compartments. This item is considered to be resolved.
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(Closed) Openitem(282/88005-03): Review of modification identified a marginal cable load carrying condition in MCC 1AB1. Power supply has been rerouted and extra cable run deleted to provide adequate load carrying capacity in cables to MCC 1ABl. The station blackout modification will provide permanent corrective action to assure adequate load carrying capacity of feeder cables to MCC 1ABl. This item is closed.
(Closed) Unresolveditem(282/88012-01;306/88012-02):
Revise response time methodology to support safety analysis.
The inspector reviewed the results of response time testing for both units. Response time testing.
was performed for the nuclear instrumentation, overpower delta-T, overtemperature delta-T, low pressurizer pressure and low reactor coolant flow to confirm the instrument delay times assumed in the Updated Final Safety Analysis Report (UFSAR) and the Reload Safety Evaluations (RSE).
Testing of the low reactor coolant _ flow and low pressurizer pressure trip channels have been added to the Reactor Protection Logic Time Response Test Procedure. All limiting trips are now tested as part of the Reactor Protection Logic Time Response Test on a continuing basis.
This item is closed.
3.
Station Blackout Construction Observation The inspector observed concrete placement activities at the station blackout (SBO)dieselbuilding. Observations included the first concrete placement on the north wall of the building.
The. licensee's quality control personnel performed a pre-planned piecement'of the reinforcing steel (rebar) and embeds.
Forms were clear of dirt and debris and the reber free of oil, dirt and dried concrete.
I Quality control inspection and sampling of concrete included slump tests, I
air entrainment testing and preparation of test cylinders for the 7-day and 28-day compression tests. Samples were taken at the truck mixer and the prepared test cylinders stored at the placement site for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to removal to the curing tanks at the civil test facility,
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i The inspector examined previcusly placed hardened concrete interior walls at the 687-695 elevations. Some voids and honeycombs were observed in two of the walls. These areas of deficient concrete had been identified by the licensee and nonconformance reports were being prepared to effect the-necessary repairs.
The licensee did not have a procedure for repairing voids or honeycombs in concrete. The inspector was informed that a procedure was being developed and that repairs would be performed by an approved procedure.
The inspector observed post-placement activities on the north wall concrete placement. The licensee was lax in maintaining appropriate concrete curing requirements on the north wall and sump wall placement.
Construction joints were allowed to dry before moisture was applied to the exposed concrete. This condition was corrected immediately when the licensee was notified of the deficiency.
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Review of Records The inspector reviewed documentation packages pertaining to the installation, inspection and testing activities performed for the station blackout modification. The review included results of air entrainment measurements and slump tests for 33 concrete batches. Test results indicated that all tested batches were acceptable. The inspector also reviewed the results of 28-day concrete cylinder breaks (compression tests) for ten molds of three cylinders each and determined that all break strengths exceeded the 4,000 psi design strengths. Compression strengths ronged between 4,700 psi and 6,300 psi for the 30 tests reviewed.
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Exit Interview The inspector met witn licensee representatives (denoted in Paragraph 1)
at the conclusion of the inspection and summarized the scope and findings of the inspection. The inspector discussed the likely informational content of the inspection report with regard to documents or processes reviewed by the inspector durir.g the inspection. The licensee did not identify any such documents or processes as proprietary.
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