ML17352A605
| ML17352A605 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 05/20/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17352A604 | List: |
| References | |
| GL-83-37, NUDOCS 9405310303 | |
| Download: ML17352A605 (6) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2055&4001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.
164 TO FACILITY OP RATING LICENSE NO.
DPR-31 AND AMENDMENT NO.
TO FACILITY OPERATING LICENSE NO.
DPR-41 FLORIDA POWER AND LIGHT COMPANY TURKEY POINT UNITS 3 AND 4 DOCKET NOS. 50-250 AND 50-251
- 1. 0 INTRODUCTION By letter dated September 3,
1993, Florida Power and Light Company (the licensee or FPL) proposed to revise Technical Specification (TS) 3/4.7. 1.6, "standby feedwater system,"
(renamed "standby steam generator feedwater system" by this revision) and the associated bases.
The proposed changes relate to elimination of reliance on the five "cranking" diesel generators to power the standby steam generator feedwater (SSGF) pumps.
The basis for eliminating this reliance is a plant modification which will replace the motor driver for one of the SSGF pumps with a diesel driver.
The cranking diesel generators are relied upon in the event of a fire affecting the auxiliary feedwater (AFW) system (they are not relied upon to meet the station blackout rule.)
In the event of a loss of AFW due to a fire, the motor-driven SSGF system pumps are used for decay heat removal via the steam generators.
Power to the SSGF system from the cranking diesel generators is attained through manual operator actions taken locally.
These actions take about 20 minutes to perform.
The system modifications and proposed TS changes were undertaken to eliminate the high maintenance costs and remove the excessive operational burden of maintaining the operability of the non-safety-related cranking diesel generators.
With the replacement of the motor driver with a diesel driver on one of the SSGF
- pumps, the diesel-driven pump will be relied upon for decay heat removal in the event of a fire which disables the AFW system coincident with a loss of offsite power.
The proposed revision to TS 3/4.7. 1.6 takes this into account by adding surveillance requirements for the'iesel-driven SSGF pump.
- 2. 0 EVALUATION The safety-related auxiliary feedwater system for Turkey Point 3 and 4
contains three shared turbine-driven AFW pumps.
The non-safety-related SSGF system provides added reliability and diversity as a back-up to the AFW system during events involving a loss of main feedwater.
The SSGF presently uses two shared motor-driven pumps, either of which can supply either or both units.
Credit is taken for the SSGF to meet the requirements of 10 CFR Part 50, Appendix R, in the event of a fire in two fire zones containing AFW equipment.
Because of this credit it was necessary to require operability of at least two 94053i 0303 940520 PDR ADOCK 05000250 P
of the five cranking diesel generators in order to provide power to the 3C and 4C 4. 16 Kv switchgear in the event of a loss of offsite power during a fire disabling the AFW system.
The cranking diesel generators are capable of providing a backup power source to Units 3 and 4.
Manual operator actions taken locally are required to connect this backup power source and the SSGF can be made operable via the cranking diesel generators within 20 minutes.
In order to eliminate the high maintenance costs associated with the cranking diesel generators and remove the potentially high operational burden from nuclear plant personnel, the licensee proposed replacing the electric motor for one SSGF pump (Pump "B") with a dedicated diesel driver, thereby eliminating reliance on the cranking diesel generators.
In the event of a fire which disables the AFW system, coupled with a loss of offsite power, the diesel-driven SSGF pump will be relied upon to deliver the required feedwater flow to the steam generators of both units.
One SSGF pump, either the motor or diesel driven pump, is adequate to meet the decay heat removal requirements of both units assuming a loss of offsite power and the unavailability of the AFW system.
Both SSGF pumps will still act as diverse backups to the AFW system under all circumstances, but only the diesel-driven pump will be given credit for operating in the event of an AFW disabling fire coincident with a loss of offsite power.
Therefore, the diesel-driven pump is necessary to meet the requirements of 10 CFR Part 50, Appendix R with respect to safe shutdown following a fire which disables the AFW system.
TS 3/4.7. 1.6 presently allows one SSGF pump to be out of service for up to 30 days before a special report is required to be issued.
With both SSGF pumps inoperable, the present TS requires that, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the NRC is notified and a cause for inoperability and a plan to restore a pump to operable status must be provided.
In addition, a special report must be submitted to the NRC.
With the proposed revision, these actions will basically remain the same except that with both pumps inoperable, the licensee must restore a
pump to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or notify the NRC within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
The staff concurs with this change which allows the licensee to restore the pumps to an operable status.
This change is also consistent with the intent of the staff's August 13, 1986, Safety Evaluation (License Amendments 118 and 112) for the SSGF system TS where the staff stated that with both pumps unavailable the problems would be corrected within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or a Special Report would be submitted.
As proposed, the revised specification could result in the diesel-driven pump being inoperable for up to 30 days without any specific action taken.
Although the motor-driven pump would still be available, its onsite power supply is no longer required to be operable by the TS.
- However, a 30-day outage time is consistent with other fire protection safe shutdown equipment such as the remote shutdown panels.
The 30-day outage time is acceptable because the equipment is only relied upon in the event of a disabling fire in a specific plant area.
As a result of the design
- changes, Surveillance Requirements (SR) 4.7. 1.6.3 and 4.7. 1.6.4 have been revised and
- added, respectively.
The proposed changes to the SR remove. the reference to the cranking diesel generators and provide specific requirements for the diesel-driven SSGF pump.
The proposed SR.
changes are necessary to be consistent with the design changes and reflect the new reliance on the diesel-driven pump to meet the requirements of 10 CFR 50, Appendix R.
The proposed changes are, therefore, acceptable.
The Bases section for TS 3/4.7. 1.6 has also been revised to remove references to the cranking diesel generators and a description of the role of the diesel-driven pump has been added.
The Bases section changes adequately reflect the SSGF design changes and are necessary for consistency with the revised specifications, and are, therefore, acceptable.
Based on its review and evaluation of the licensee's proposed changes to TS 3/4.7. 1.6, as described
- above, the staff concludes that the proposed changes are necessary to be consistent with the proposed system design
- changes, satisfy the requirements of 10 CFR 50, Appendix R with respect to safe shutdown in the event of a fire, and maintain the SSGF system licensing commitments associated with AFW diversity and reliability, i.e.,
Generic letter 83-37, "NUREG-0737 TECHNICAL SPECIFICATIONS."
The staff, therefore, concludes that the proposed changes are acceptable and should be approved.
3.0 STATE CONSULTATION
Based upon the written notice of the proposed amendments, the Florida State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
These amendments involve a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The NRC staff has determined that the amendments involve 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 previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (58 FR 52985).
Accordingly, these amendments meet 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 the amendments.
- 5. 0 CONC LUS ION Based on the staff evaluation in Section 2.0 above, the staff concludes that the proposed Technical Specifications changes are acceptable.
The Commission has concluded, based on the considerations discussed
- above, that:
(1) there is reasonable assurance that the health and safety of the public wi,ll not be endangered by operation in the proposed
- manner, (2) such
activities will be.conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principle Contributor:
W. LeFave Date:
May 20, 1994
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