ML18153C815
| ML18153C815 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 10/17/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18153C814 | List: |
| References | |
| NUDOCS 9111200259 | |
| Download: ML18153C815 (4) | |
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE INSERVICE TESTING PROGRAM AND REQUESTS FOR RELIEF VIRGINIA ELECTRIC AND POWER COMPANY SURRY NUCLEAR POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-280 AND 50-281
1.0 INTRODUCTION
The Code of Federal Regulations, 10 CFR 50.55a{g), requires that inservice testing (IST) of certain ASME Code Class 1, 2, and 3 pumps and valves be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable addenda, except where specific written relief has been requested by the licensee and ~ranted by the Commission pursuant to Subsections (a)(3)(i),
(a)(3)(ii), or (g)(6)(i) of 10 CFR 50.55a.
In requesting relief, the licensee must demonstrate that:
(1) the proposed alternatives provide an acceptable level of quality and safety; (2) compliance would result in hardship or unusual dif-ficulty without a compensating increase in the level of quality and safety; or (3) conformance with certain requirements of the applicable Code edition and addenda is impractical for its facility.
These regulations authorize the Convnission to grant relief from ASME Code requirements upon making the necessary findings.
The NRC staff's findings with respect to granting or not granting the relief requested as part of the licensee's IST Program are contained in this Safety Evaluation {SE).
This SE covers the interim pump relief~requests P-18 for Unit 1, P-15 for Units 1 and 2, and P-2 for Unit 2 as described in Virginia Electric and Power Company's (the licensee) letter dated July 12, 1991, which supersedes all previous submittals on this subject. The licensee's program is based on the requirements of Section XI of the ASME Code, 1986 Edition.
2.0 EVALUATION The licensee's request for interim relief from the +/-2.0% instrument accuracy requirements of ASME Section XI Subparagraph IWP 4110, Table IWP 4110-1, for the residual heat removal, auxiliary feedwater and emergency service water pumps for Units 1 and 2 are identified in interim relief requests P-15 and P-18, which requested relief until the first scheduled test after September 30, 1991.
Relief is requested on the basis that the interim period to the first scheduled test for these pumps after September 30, 1991, is necessary to allow for engineering analysis of the instrumentation uncertainties and for revisions
( 9111200259 911017 PDR ADOCi<. 05000280 P
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I e of calibration and test procedures.
Interim relief requests P-15 and P-18 also include the instruments for the component cooling pumps.
However, local flow indicators will be required to bring these flow instrument accuracies to within
+/-2.0%.
These indicators will be installed at the existing flow elements by April 30, 1992.
The instruments for the inside recirculation spray pumps are also included in the interim relief requests.
However, these pumps will be retested during the next scheduled refueling outages when a temporary dike can be installed in containment to support pump testing. The licensee's evaluation of the loop instrument inaccuracies for all these pumps were found to be within
+/-2.6%.
The licensee performed an evaluation using a 2.6% accuracy bias, to determine if the decreased instrument accuracies affected the operable status of the pumps, considering the last performance test data of each pump.
The licensee's evaluation concluded that the pumps have adequate operational margin after-the effects of the decreased instrument accuracies were considered and compared to the Section XI acceptance criteria.
The licensee's request for interim relief from flow measurement requirements of ASME Section XI Subparagraph IWP 4110, Table !WP 4110-1, for the chemical and volume control (charging system) pumps for Unit 2 until the next refueling outage is defined in interim relief request P-2.
The basis for the interim relief request is that the newly installed flow instrumentation indicator was sized for flow testing using recirculation lines with flow rates ranging from 0 to 150 gpm.
The transmitters at this flow rate produce a very low differential pressure signal. It is extremely difficult to calibrate the flow transmitters with the existing calibration equipment.
New calibration equipment is being pursued to solve the calibration problem. If the newly installed equipment cannot be calibrated with the new calibration equipment, a different test method will be developed.
The interim alternate testing proposed by the licensee is equivalent to the recommended testing of Generic Letter 89-04, Position 9~ where flow can only be through a non-flow instrumented minimum flow path during quarterly pump testing and a path exists at refueling outages to perform testing of the pumps under full-flow conditions. The st~ff has determined this alternate testing will provide reasonable assurance of operational readiness in the interim.
The licensee's request for interim relief from the requirements of ASME Section XI have been reviewed by the staff. The staff concludes that the interim relief request with the conditions contained within the requests will provide reasonable assurance of the operational readiness of the pumps to perform their safety-related functions.
The staff recommends granting of interim relief based upon the fulfillment of conditions stated by the_
licensee in its basis for each relief request and the alternative proposed testing. The recommended interim relief for the residual heat removal, auxiliary feedwater, and emergency service water pumps identified in relief requests P-15 for Surry Units, 1 and 2 and P-18 for Surry Unit 1 will expire after the first scheduled test after September 30, 1991.
The interim relief for the component cooling pumps will expire after April 30, 1992, and the interim relief for the inside recirculation spray pumps will expire at the next refueling outage for each unit, currently scheduled for April 1992 for Surry Unit 1 and February 1993 for Surry Unit 2. The interim relief for the Unit 2 charging system pumps identified in relief request P-2 will expire at the next refueling outage.
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3.0 CONCLUSION
The staff has determined that granting relief, pursuant to 10 CFR 50.55a(a)(3)(ii) is authorized by law and will not endanger life or property or the conunon defe.nse and security and is otherwise in the public interest.
In making this determination, the staff has considered that the alternate testing will provide reasonabl£ assurance of operational readiness and that compliance would result in a hardship without a compensating increase in safety and level of quality.
The staff has not included in this evaluation the non-code alternative testing relief request PNC-1 with respect to granting relief since non-code components are not encompassed in the provisions of 10 CFR 50.55(a).
However, the basis for alternative testing and proposed testing is considered reasonable.
Date: October 17, 1991 Principal Contributor:
F. Grubelich
Distribution for Relief for Surry Units 1 and 2 dated: October 17, 1991 Docket File NRC & Local PDRs PDII-2 RF T. Murley/F. Miraglia J. Partlow C. Rossi S. Varga G. L.ainas D. Mi 11 er B. Buckley OGC E. Jordan G. Hill (4)
GPA/PA ACRS (10)
OC/LFMB J. Wechselberger