ML20070D412
| ML20070D412 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 02/20/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20070D407 | List: |
| References | |
| NUDOCS 9102280251 | |
| Download: ML20070D412 (3) | |
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<,, m.....f SAFETY EVALUATION BY THE OrrlCE Or ta' CLEAR REACTOR REGULATION RELATED TO AMEtt0MEtlT 140. 127 TO FACILITY OPERATING LICENSE NO. NPF-7 VIRGitt1A ELECTP.it AND POWER COMPANY OLD DOMINION ELECTRit COOPERATIVE NOPTH ANNA POWER STATION, UNIT NO. 2 DOCKET tl0. 50-339
1.0 INTRODUCTION
Virginia Electric and Power Company (the licensee) submitted a proposal to amend the North Anna, Unit 2 (NA-2) Operating License NPF-7 and change a previous commitment on North Anna, Unit 1 (NA-1) in a letter cated October 29, 1990, as supplemented January 18, 1991.
The proposed changes involve eliminating disassembly and inspection requirements on both inside recirculation spray pumps (IRSPs) in each unit (4 total pumps).
These inspections are currently scheduled to be conducted every 5 years. The licensee indicated that the IRSP inspections are no longer necessary because full-flow testing of these pumps is conducted during each reactor refueling outage in accordance with ASME Section XI.
The Jar ary 18, 1991 letter provided additional information requested by the staff regarding the testina of the IRSPs.
The additional information did not alter in any way the staff s initial determination of no significant hazards consideration as noticed in the federal Reoister on December 26, 1990 (55 FR 53077).
2.0 OlSCUSSION At the time NA-1&2 were licensed, the IRSPs were not expected to be periodically flow tested because there was no means to provide adequate suction to the pumps unless a dam was constructed in the containment sump.
The NRC's Safety Evaluation Report, Supplement 9, dated March 1978, identified that the mechanical reliability of the IRSPs could be demonstrated with modal analysis of the IRSP for comparison with the successfully tested outside recirculation spray pumps (ORSPs) because of the similarity of the designs of the IRSPs and the ORSPs.
In Supplement 10, the NRC stated that the modal analysis of the IRSPs demonstrated that flow testing of the ORSPs would provide a basis of comparison with the IRSPs.
The testing of the ORSPs confirmed the ability of these pumps to meet their required safety function.
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. To provide continuing assurance of the mechanical reliability of the IRSPs, the staff required in Supplement 10 that the test interval for dry-bump testing be increased to quarterly.
The staff also required that the pumps be removed and inspected, that the bearings be replaced if necessary, and that the pump shaf t be optically aligned prior to reinstall 1 tion. This ins least once every 5 years and is License Condition 2.C.(pection was required at 15)(c) in the NA-2 Operating License No. NPF-7.
By letter dated September 14, 1979, the licensee also committed to perform the same disassembly and inspection procedure on the Unit 1 1RSPS.
Each of the four IRSPs has been disassembled and inspected twice, with the exception of the NA-1 "B" 1RSP, which has been disassembled and inspected once.
The inspections that were conducted revealed no significant degradation of the pump internal components. After each inspection, new pump bearings were installed.
The licensee stated that the bearings tend to incur damage during the pump disassembly because of the brittie Learing material.
In a March 25, 1987, letter from the licensee to the NRC, the licensee submitted a revised IST Program containing a request for relief from performing ASME Code Section X1, required quarterly flow testing of the IRSPs.
The licensee proposed to conduct dry-bump testing as an alternate testing method, which was already being performed on a quarterly basis.
Based upon the staff's knowledge that flow testing of similar pumps was being performed at another plant, the licensee was granted relief from quarterly flow testing and allowed to conduct quarterly dry-bump testing provided the licensee performed full-flow testing of all IRSPs every refueling outage.
This testing requires the erection of a temporary dam inside containment.
The NA-1 IRSPs were full-flow tested during the 1989 refueling outage and the NA 21RSPs were full-flow tested during the 19d7,1989 and 1990 refueling outages, in all testing performed, all hydraulic and vibrational pump performance parameters were within acceptable limits.
3.0 EVALUATION The licensee has made the necessary system and procedural modifications to perform full-flow testing every refueling outage.
Full-flow testing has been conducted on all four IRSPs in each unit. The NA-1 pumps were flow tested in 1989 and the NA-2 pumps were flow tested in 1987, 1989, and 1990. The results have all been acceptable. The requirement to disassemble and inspect these pumps stemmed from the licensee's original proposal to perform dry-pump testing in lieu of flow testing.
Since the licensee has agreed to, and has been successfully flow testing these pumps, the requirement to periodically disas-semble and inspect these pumps is no longer a ppropriate.
License Condition 2.C.(15)(c) may, therefore, be deleted from tie NA-2 Operating License and the staff finds withdrawal of the licensee's NA-1 commitment to be acceptable.
4.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change to a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. We have determined that this amendment involves no significant l
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3 increase in the amounts, and no significant change in the types, of any ef fluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure, The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding, Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51,22(c)(9).
Pursuant to 10 CFR 51,22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
5.0 CONCLUSION
We have concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Date: February 20, 1991 Principal Contributor:
J. Colaccino
.