ML17254A238
| ML17254A238 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 02/27/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17254A237 | List: |
| References | |
| NUDOCS 8503050432 | |
| Download: ML17254A238 (6) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THF OFFICE OF NUCLFAR REACTOR REGULATION APPENDIX R TO 10 CFR PART 50, ITEMS III.G.3 AND III.I.
P,.
E.
GINNA NUCLEAR POWER PLANT ROCHESTER GAS AND ELFCTRIC CORPORATION DOCKET NO. 50-244
1.0 INTRODUCTION
On February 17, 1981, the fire protection rule for nuclear power plants, 10 CFR 50.48 and Appendix R to 10 CFR Part 50, became effective.
This rule required all licensees of plants licensed prior to January 1,
1979 tn submit by March 19, 1981:
( 1) plans and schedules for meeting the applicable requirements of Appendix R,
<2) a design descripti'on of any modifications proposed to provide alternative safe shutdown capability pursuant to Paragraph III.G.3 of Appendix R, and (3) exemption requests for which the tolling provision of Section 50.48(cl(6) was to be invoked.
Section III.G of Appendix R is a retrofit item to all pre-1979 plants regardless of previous safety evaluation positions and resolutions.
The criteria contained in Section III.Lof Appendix R are used for those cases where licensees are incorporating alternate nr dedicated shutdown capability.
By letter dated lanuary 16, 1984, Rochester Gas and Flectric Corporation (RG8E), the licensee for Ginna Nuclear Power Plant provided a revised proposed alternative shutdown design in lieu of the modifications previously proposed by the licensee to achieve compliance with the requirements nf Appendix R, Sections III.G.3 and III.L.
Our evaluation of the licensee's most recent proposal is presented below.
This evaluation supersedes those previously provided on this sub,iect.
The licensee has described the post-fire shutdown capability for the Ginna Nuclear Power Plant in submittals dated January 16, 1984, April 9, 17, and 27,
- 1984, May 3, 1984, October 4, 1984 and.lanuary 16, 1985.
Additional information and clarification was obtained in meetings with the licensee on February 22,
- 1984, November 30, 1984 and January 10, 1985.
The licensee has provided a safe shutdown analysis for a fire event and has demonstrated that adeouate alternative shutdown methods exist f'r those areas required in order to assure safe shutdown.
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2.0 SYSTEMS USED FOR POST-FIRE SAFF SHUTDOWN A.
Systems Required for Safe Shutdown In the event of a fire and loss of o~fsite power, the followinq systems are used to provide the shutdown capability for Ainna Nuclear Power Plant.
Reactor shutdown is initiated from the control room by a manual scram of the control rods, if an automatic scram has not occurred.
Reactor coolant inventory and reactor shutdown reactivity are maintained by one of the two charging pumps taking suction from the refuelinq water storage tank.
Primary system pressure control is accomplished by use of a charging pumo.
Overpressurization protection for the primary system is provided by the pressurizer safety valves.
Decay heat removal is accomplished by providing feedwater to the steam generators with either the turbine driven auxiliary feedwater (AFW) pump or the standby AFW pump.
Energy is released via steam discharge through the Atmospheric Steam Dump Valves.
Cold shutdown conditions can be achieved and maintained by utilizing solid steam generator operations.
This method was previously approved by the staff and a separate SER (dated April I 1, 1983) was issued for Ainna approving use of solid steam generator shutdown.
The findings in that SFR with respect to this method are still valid.
B.
Areas Where Alternate Shutdown Is Re uired The licensee has provided alternative shutdown capability for the control room, relay room, air handlina room, battery room, cable tunnel, and auxiliary building basement/mezzanine.
The alternate shutdown method will be accomplished independent of the above areas by procedural mo.ans with actions performed at local shutdown stations or locallv at the equipment.
The licensee has provided a
summarv o+ the functions for which alternate shutdown methods may be needed, and the manual actions required to accomplish each nf the identified functions which have been described in the plant's procedures.
Alternate process monitoring capability and instrumentation is availahle at two backup indication oanels.
C.
Remainina Plant Areas All other areas o~ the plant not required to have an alternate safe shutdown system will comply with the requirements of Section III.G.P of Appendix R, unless an exemption request has been approved bv the staff.
EYALUATION D.
Performance Goals The performance goals for nost fire safe shutdown for reactivity control, reactor coolant makeup, reactor coolant pressure control and decay heat removal can be met using the existing systems and equipment indicated in Section A above.
The control of these functions can be accomplished using the alternate shutdown methods or the control room depending on the location of the fire.
The licensee's alternate shutdown method relies on procedures and actions at local shutdown stations or at the required equipment.
The process monitoring capability provided at the backup indication panel which is par t of the turbine driven auxiliary feedwater panel are reactor hot and cold leg temperatures, steam generator level and
- pressure, and turbine-driven auxiliary feedwater pump flow.
Pressurizer
- pressure, and level and charging pump discharge header pressure and flow indication are provided at the backup panel which is part of the charging pump room panel.
Source range flux monitoring is provided at a
separate location.
The capability tn record other 'local indications for tank levels and diagnostic pressure, temperature or flow indications of support systems will be identified in the shutdown procedures.
The available support systems for post-fire safe shutdown are redundant diesel generators and their associated vital buses, the emergency water
- system, and power supply for the backup indication panel.
E.
72 Hour Re uirement The licensee has stated that the plant can achieve cold shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> without offsite power by using the alternative shutdown system.
F.
~Re airs The licensee stated that the only repairs necessary to achieve cold shutdown are those for the pressurizer PORY and those to provide a
long-term source of DC power.
The installation of a jumper cable between the Technical Service Center (TSC) vital battery and the DC power trains A and 8 with a manual throwover switch will provide a long term supply of dc power.
In the event of the loss of the control/power cables to the
- PORVs, a procedure will be provided for repair of the damage.
The PORYs are needed only to go to cold shutdown.
The equipment required to accomplish these repairs will be stored onsite and procedures for them will be provided.
G.
Associated Circuits Protection To assure the availability of the above systems followina a fire, the licensee identified associated circuits ?hat could prevent operation or cause maloperation of shutdown systems and equipment.
For identified associated circuits, protection fnr the safe shutdown systems was provided in accordance with NRC guidelines as outlined in the following paraqraphs.
1.
Common Power Source The licensee indicated that all circuits of the ac and dc emergency power system were reviewed to assure proper coordination of breakers and fault interrupting devices.
The emergency power system is used to supply essential power for the post-fire shutdown systems.
Coordination of circuit protective devices was part of the original electrical system desion of the Ginna Nuclear Power Plant.
- Thus, by design of the plant, assnciated circuits of this type do not exist at Ginna.
2.
Common Enclosure The licensee indicated that coordinated electrical circuit fault protection was provided by design for all cases of common enclosures of associated circuits.
Also, for cases of common enclosure, electrical cable penetrations for safe shutdown eauipment are sealed to the same rating as the barrier, and therefore the spread of fires via associated circuits is not a concern.
The licensee identified a
number of circuits where fire-induced failures may adversely affect the safe shutdown capability.
As a
- result, new isolation devices and/or procedures were nroposed to prevent spurious operation or to provide indication of a spurious operation with subseouent operator action.
The disabling of certain motor-operated valve power breakers (such as the RHR/RCS interface) will prevent their spurious operation.
Also, manual isolation of dc control power components such as
- PORVs, ac and dc motor-operated
- valves, and solenoid valves will prevent or terminate their potential spurious operation.
H.
Safe Shutdown Procedures and Manpower The licensee has developed and implemented detailed written procedures for obtainina a safe shutdown condition qiven a fire event.
These procedures are part of the current operational and emergency instructions.
The manpower necessary for accqmplishjng thewperatinns required for alternate shutdown is available at the plant at all times.
Members 6f the fire brigade are not included in the shutdown manpower reouirements.
3.0 CONCLUSION
Based on our review, we conclude that the Ginna Nuclear Power Plant post-fire alternate shutdown design provides one train of systems necessary to achieve and maintain safe shutdown conditions and thus meets the requirements of Appendix R to 10 CFR 50, Sections III.G.3 and III.L with respect to safe shutdown in the event of a fire in the areas identified in Section II.B of this SER and is therefore acceptable.
4.0 ACKNOh'LFDGEMENT A. Singh was the principal contributor to this Safety Evaluation.
Dated:
February 27, 1985