ML18005A399
| ML18005A399 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 04/15/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18005A398 | List: |
| References | |
| NUDOCS 8804210460 | |
| Download: ML18005A399 (5) | |
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H UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION CAROLINA POWER 8 LIGHT COIIPANY, et al.
SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400
- 1. 0 INTRODUCTION In Supplement No.
4 to the staff's Safety Evaluation Report, dated October 1986, it was concluded that the licensee s initial test program was acceptable.
Subsequent to the issuance of Supplement No.
4 in October 1986, the licensee has made changes to the Shearon Harris Nuclear Power Plant, Unit 1, (SHNPP) Initial Test Program described in letters dated June 5, July 27, and October 12, 1987.
The staff's evaluation of these changes is delineated below.
2.0 EVALUATION Lar e Load Reduction and Generator Tri from 100 Percent Power Regulatory Guide (RG) 1.68, Appendix A.5.n.n, provides an acceptable approach for each facility to demonstrate that
"... the dynamic response of the plant is in accordance with design for the case of full load rejection."
FSAR Subsection 14.2.12.2. 18, Large Load Reduction and Generator Trip from 100 Percent
- Power, and Subsection 14.2.1.2 adequately describe and commit to perform such a test prior to commercial operation, and further describe two other tests:
50 percent load r ejections from 75 percent and 100 percent power.
By letter dated June 5, 1987 (Change 818),
CPSL has deferred two of these three tests, the two that are to be initiated from 100 percent power, until "the plant is fully modified to approve the design aspects of these tests."
By letter dated October 12,
- 1987, CPSL revised their position by stating that they have demonstrated compliance with RG 1.68, Appendix A.5.n.n, and that no further transient testing is required.
The staff s position regarding each of these two tests is described below.
50 Percent Load Rejection Test The 50 per cent load rejection test from full power is not a specifically required test and, therefore, does not have to be conducted during the initial test program.
88042l0460 880415 PDR ADOCK 05000400 PDR
100 Percent Load Re 'ection Test RG 1.68 states each facility should conduct a full load rejection test and a turbine trip test at 100 percent power; however, it does state that the two tests can be combined if the test is initiated by simulating an automatic or manual trip of the generator main breakers.
Each of these two methods of test initiation are discussed below.
The simulation of an automatic generator trip would result in a turbine trip and subsequent fast bus transfer.
The plant response to a turbine trip from 100 percent power is tested as described in FSAR Subsection 14.2.12.2.19.
However, the generator trip, unlike the turbine trip, would subject the turbine-generator to the maximum credible overspeed condition.
As discussed in the letter dated October 12, 1987, the turbine overspeed issue has been addressed.
CPSL submitted its turbine overspeed test procedure to the NRC along with additional information contained in letters dated November 21, 1986 and December 5, 1986.
The staff deter-mined, in Attachment 6 of Hemorandum dated December 10, 1986 to the Executive Director, Advisory Committee on Reactor Safeguards, that the calculational approach for assuring that turbine roll-up following a turbine tr ip will not exceed the design over speed limit is an acceptable alternative to actual testing of the system.
CPAL states in a letter dated October 12, 1987, that a full load rejection initiated by the manual opening of the generator output breakers is expected to result in a reactor trip, unlike the plant response currently identified in FSAR, Subsection 14.2.12.2. 18.
The reactor trip would result in a turbine trip.
The turbine trip would normally initiate (via the main generator lockout relays) a fast bus transfer after a 30 second delay.
However, since the standby power source availability is determined by the position of the generator output breakers (which were opened to initiate the test),
the fast transfer would be inhibited.
Non-safety related power would be lost and the emergency buses would be fed from the emergency diesel generators, simulating a loss of offsite power event when in fact offsite power would be readily available.
CPSL has conducted a loss of offsite power event (FSAR Subsection 14.2.12.2.21) at 10 to 20 percent power in accordance with RG 1.68, Appendix A.5.j.j, and, therefore, does not need to repeat the test at 100 percent power.
It is the staff's position that CP8L has adequately demonstrated com-pliance with Regulatory Guide 1.68, Appendix A.5.n.n, and that conduct of a full load rejection test from 100 percent power is, therefore, not required.
Load Swin Test Summar By letter dated June 5, 1987 (Change 819),
CP8L has deleted the 10 percent load swing from 100 percent power from the test program.
CPKL states that this test is bounded by the heater drain pump transient that occurred on Nay 27, 1987, and is adequately demonstrated by other startup tests.
The staff concurs with this deletion.
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3 Solid'Waste Processin S stem Test Summar By letter dated July 27,
- 1987, CPSL has transferred the responsibi lity for completion of certain portions of the Solid Maste Processing System test from the Start-up Engineers to the System Engineers in the Technical Support Unit.
Because
+he substance of these tests has not changed, and deferral, of this test does not impact the health and safety of the public, the staff finds this change acceptable.
3.0 CONCLUSION
Based on our evaluation of the above information, the staff concludes that the changes to the initial test program discussed above are acceptable.
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