ML18009A690
| ML18009A690 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 10/05/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18009A689 | List: |
| References | |
| NUDOCS 9010160193 | |
| Download: ML18009A690 (6) | |
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0 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.
22 TO FACILITY OPERATING LICENSE NO.
NPF-63 CAROLINA POWER 8
LIGHT COMPANY et al.
SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400
1.0 INTRODUCTION
By letter dated September 27,
- 1990, as supplemented September 28,
- 1990, the Carolina Power 5 Light Company submitted a request for changes to the Shearon Harris Nuclear Power Plant, Unit l (Harris).
il The Technical Specification changes proposed in this submittal revise the acceptance criteria for Surveillance Requirement 4.7.1.2. 1.a. 1 associated with the monthly testing on a staggered test basis of the two motor-driven AFW pumps.
Specifically, this change revises Surveillance Requirement 4.7.1.2.1.a.1 to require that the motor-driven AFW pumps be verified to develop a differential pressure that (when temperature compensated to 70'F) is greater than or equal to 1558 psid at a recirculation flow of greater than or equal to 50 gpm.
The existing surveillance requirement verifies that the motor-driven AFW pumps develop a discharge pressure of greater than or equal to 1590 psig at a recirculation flow of greater than or equal to 50 gpm.
This acceptance criteria did not consider the effect of condensate storage tank (CST) level or temperature
.when specifying a
discharge pressure of 1590 psig.
A Temporary Waiver of Compliance was issued on September 28, 1990, to permit utilization of this change until the amendment could be issued.
2.0 EVALUATION The AFW pumps are required to be demonstrated operable at least once per 31 days on a staggered test basis.
This equates to a quarterly test.
The test requires that each motor-driven pump develop a discharge pressure of greater than or equal to 1590 psig at a recirculation flow of greater than ot equal to 50, gpm.
This surveillance is intended to verify that each motor-driven AFW pump is capable of delivering a total feedwater flow of 475 gpm at a pressure of 1217 psig to the entrance of the steam generators.
This capacity, in conjunction with the turbine driven AFW pump, is sufficient to ensure that adequate feedwater flow is available to remove decay heat and reduce the reactor coolant system temperature to less than 350'F when the Residual heat removal system may be placed into operation.
90i0i60i93 901005 PDR ADOCK 05000400 P
PDC The pump surveillance is conducted with the flow paths from the pump discharge to the steam generators isolated.
A small installed recirculation line passes the minimum required flow back
+o the condensate storage tank.
This approach was taken in lieu of directing the pumps'ischarge to the steam generators in order to minimize the number of thermal cycles on the steam generators'FW nozzles.
This technique results in running the motor-driven AFW pump near its shut off head.
The assumption is that by verifying a sufficiently high discharge pressure at a flow significantly less than that required for the pump to perform its design function, one would be able to plot a point and compare it with respect to the pump operating curve.
As long as the pressure exceeded the value in Technical Specifications, the pump could perform its design function.
When surveillance measurements were made locally rather than on the installed instrumentation to reduce pressure fluctuations, the pump pressure did not pass the surveillance requirement.
In diagnosing the problem, it was noted that the limit did not adequately account for level or temperature in the condensate storage tank (CST).
The licensee established flow to the steam generator and measured six data points on the vendor pump curve to verify that pump performance is adequate to meet system design.
By letter dated September 27, 1990, the licensee proposed that the surveillance requirement 4.7.1.2.1.a.l be changed to require that the motor-driven AFW pumps be verified to develop a differential pressure that (when temperature compensated to 70'F) is greater than or equal to 1558 psid at a recirculation flow of greater than or equal to 50 gpm.
The staff has reviewed the proposed change to the surveillance requirement and the testing performed during the surveillance.
The licensee has demonstrated that the pump is capable of supplying its design flow and the proposed surveillance will compensate for water temperature and CST level.
Therefore, the staff finds the proposed surveillance requirement on the motor-driven auxi liary =feedwater pumps is acceptable.
3.0 STATEMENT OF EMERGENCY CIRCUMSTANCES In the past, the values recorded for the AFW pumps discharge pressure for surveillance 4.7.1.2.1.a.1 have been acquired from installed instrumentation.
The licensee suspects that the high differential pressure (approximately 650 psid) across the pumps'ormally open discharge isolation valves that are closed for this test has recently resulted in a small amount of leak-by.
This suspected leak-by results in small pressure surges in the line causing the pump discharge check valve to chatter which increases the magnitude of the surges.
In order to achieve a dampened pressure reading at the pump discharge, an electronically dampened pressure transmitter was installed at the pump discharge.
When the surveillance was conducted with the locally installed pressure transmitter a discharge pressure of 1587 psig was
recorded which falls below the TS value of 1590.
This made the 'A'rain motor driven AFW pump inoperable at 1:08 p.m. Tuesday, September 25, 1990.
The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> limiting condition for operation requires that the plant enter the six hour shutdown portion of the action statement if the pump is not restored to an operable condition by 1:08 p.m. Friday, September 28, 1990.
During testing, it was noted that the surveillance requirement did not account for variations of water level or temperature in the condensate storage tank (CST).
The licensee measured six points on the pump head curve which confirmed that the pump was capable of supplying its design flow and demonstrated that the surveillance failure had no safety significance.
The licensee requested the change by phone and submitted the TS amendment and request for Temporary Waiver of Compliance on September 27, 1990.
This event was not foreseen due to the repeated successful performance of this surveillance since Harris began commercial operation on Nay 2, 1987.
The pump underwent a detailed inspection during the last refueling outage in the fall of 1989 and was found to be in satisfactory condition.
Since the pump had a history of successfully passing this surveillance, the licensee could not reasonably have anticipated that a
combination of specially installed instrumentation and unaccounted for level and temperature conditions in the CST would result in a failed surveillance.
Therefore, the staff has determined that the licensee has not abused the emergency provisions of 10 CFR 50.91(a)(5) in this instance.
Since the issuance of this amendment will prevent the unnecessary shutdown of the plant, the Commission has determined that there are emergency circumstances warranting prompt approval.
4.0 FINAL DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION The Commission's regulations in 10 CFR 50.92 state that the Commission may make a final determination that a license amendment involves no significant hazards consideration if operability of the facility in accordance with the proposed changes would not:
1.
involve a significant increase in the probability or consequences of any accident previously evaluated, or 2.
create the possibility of a new or different kind of accident from any accident previously evaluated, or 3.
involve a significant reduction in a margin of safety.
The licensee evaluated the request in light of these three criteria.
In regard to the first'riterion, the licensee determined that the proposed amendment would not involve a significant increase in the probability or consequences of any accident previously evaluated since no safety-related equipment, safety function or plant operation will be changed as a result on this proposed change.
The change does not change the design, materials or construction standards applicable to the the AFH pumps.
In regard to the second criter'.on, the 'licensee determined that the proposed amendment will, not create the possibility for a new or different kind of accident from any accident previously evaluated since only the surveillance requirement is changed.
The change to the surveillance requirement is in a form so that the criterion is independent of CST level and may be corrected for CST water temperature.
In regard to the third criterion, the licensee determined that the proposed amendment will not involve a significant reduction in margin of safety since the proposed, change continues to ensure that each AFW pump is capable of delivering a total feedwater flow of 475 gpm at a pressure of 1217 psig to the entrance of the steam generator.
This capacity, in conjunction with the turbine-driven AFW pump, is sufficient to ensure that feedwater flow is available to remove decay heat and reduce the reactor coolant system temperature to less than 350'F where the residual heat removal system may be placed into operation.
The staff has evaluated the licensee's submittal and agrees that it satisfies the standards of 10 CFR 50.92.
Therefore, the staff has made a
final determination that the proposed amendment involves no significant hazards consideration.
5.0 STATE CONSULTATION
The appropriate representative of the State of North Carolina was notified of this amendment.
The State of North Carolina has no comments.
6.0 ENVIRONMENTAL CONSIDERATION
This amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes the surveillance requirements.
The staff has determined that the amendment involves no significant increase in the
- amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Commission has made a final no significant hazards consideration finding with respect to this amendment.
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 environ-mental assessment need be prepared in connection with the issuance of this amendment.
0 (0
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- 7. 0 CONCLUSION The staff has 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, (2) such activities will be conducted in compliance with the Coomission's regulations, and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated:
October 5, 1990 Princi al Contributors:
R. Becker