ML19318A473

Responds to IE Bulletin 80-12, Decay Heat Removal Sys Operability. Redundancy May Be Provided by Having Two RHR Trains Operable.Diversity May Be Provided in Modes 2-5 by Having Operable Steam Generators

ML19318A473
Person / Time
Site:	Farley
Issue date:	06/09/1980
From:	Clayton F ALABAMA POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
IEB-80-12, NUDOCS 8006230182
Download: ML19318A473 (4)

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'* 80b h 8$SYrNt e Post Office Box 2641 Birmingham. Alabama 35291 VO dh # s/

Telephone 205 323-5341 -7 mx F. L. CLAYTON, JR.

s.nior v.co e,..ia.ni Alabama Power the southem electT system June 9, 1980 Docket No. 50-348 No. 50-364 Mr. James P. O'Reilly U. S. Nuclear Regulatory Comaission Region II 101 Marietta Street, N.W.

Suite 3100 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

In response to IE Bulletin No. 80-12 " Decay Heat Removal System Operability," dated May 9, 1980, Alabama Power Company submits the following response for Units 1 and 2 of Farley Nuclear Plant.

1 Item 1 Describe changes te procedures made or initiated as a result of reviews and analyses, including the scheduled or actual dates of accomplishment, considering limiting maintenance activities to assume redundancy or diversity and integrity of RHR capability.

Response

Redundancy may be provided by having two RHR trains operable.

Diversity may be provided in Modes 1 through 5 by having 1 operable steam generators or in Modes 5 and 6 by having an  !

operable charging pump capable of providing borated water to '

j the RCS from the RWST or make-up system for a feed and bleed 5

' type operation. Diversity may also be provided in Mode 5 by )

utilizing either the pressurizer PORV's or RHR suction relief valves to " bleed" the RCS, or in Mode 6 for make-up to the reactor vessel and refueling canal. .

The current FNP technical specifications and plant operating procedures adequately address the " redundancy and diversity" g -

concerns expressed in the above referenced bulletin for Modes 1

2, 3, 4, and 6. In Modes 1, 2, and 3, both redundancy and i

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e e Mr. James P. O'Reilly June 9, 1980 diversity are assured by complying with Technical Specification 3.5.2 which requires two operable independent ECCS subsystems (each consisting of a charging pump, RHR pump and he'at exchanger and a flow path for taking suction from the RWST) and Technical Specification 3.4.5 which requires three operable steam generators.

In Mode 4, diversity is assured by complying with Technical Specification 3.4.5 (for steam generators) and Technical Specifi-cation 3.5.3 which requires at least one operable ECCS subsystem. '

Diversity is assured in Mode 6 by complying with Technical Speci-fication 3.9.8 which requires at least one operable RHR train and Technical Specification 3.1.2.1 which requires one operable boron injection flow path (consisting of one charging pump and a flow path from either the RWST or the boric acid tanks to the RCS).

In Nbde 5, compliance with Technical Specification 3.1.2.1 (boron injection flow path) and Technical Specification 3.4.9.3, which

. requires in part that two RHR relief valves or a RCS vent > 2.85 square inches be operable, ensures an alternate means of residual heat removal. Technical epecifications do not allow redundant boron injection paths (a maximum of one charging pump may be operable whenever RCS cold leg temperature is < 1800 F. due to

, overpressurization considerations) and do not require an operable RHR train. Therefore, to ensure diversity in Mode 5, Unit Operating Procedure FNP-1-UOP-2.2, entitled " Shutdown Of Unit From Hot Standby To Cold Shutdown," will be revised by June 30, 1980, to ensure that at least one train of RHR is operable.

Expediting restoration of "out of service" equipment is presently governed by Technical Specification action statement requirements which limit "out of service" time.

Item 2 Describe procedural changes made or initiated as a result of reviews and analysis, including the scheduled or actual dates of accomplisnment, considering bypassing or disabling, where applicable, automatic actuation of ECCS recirculation in addition

, to disabling High Pressure Injection and Containment Spray

Preparatory to the cold shutdown or refueling mode.

Response

Unit Operating Procedure FNP-1-UOP-2.2 (Shutdown Of Unit From Hot Standby To Cold Shutdown) will be revised by June 30, 1980 L. te require the performance of Instrumentation Maintenance p -

Procedure FNP-1-IMP-0.7 entitled '1Hodes 5 and 6 Surveillance

, Test Performance," which provides for the above bypass or a disabling requirements, except in those cases where the above t .

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Mr. James P. O'R] illy June 9, 1980 systems are required to be operable for mode changes or required tests. These procedural changes will be made for appropriate Unit 2 procedures prior to the issuance of an Operating License.

Item 3 Describe the safeguards at your facility against RHR degradation, including your assessment of their adequacy.

Response

The system is provided with two residual heat removal pumps and two residual heat exchangers arranged in separate Independent flow paths. If one of two pumps or heat exchangers is not operable, safe cooldown of the plant is not compromised; however, the time required for cooldown is extended.

The two separate flow paths provide redundant capability of meeting the safeguard function of the Residual Heat Removal System. The loss of one Residual Heat Removal System flow path would not negate the capability of the Emergency Core Cooling System since the two flow paths provide full redundancy for safeguard requirements.

, To ensure reliability, the two residual heat removal pumps are connected to two separate electrical buses so that each pump e

receives power from a different source. If a total loss of offsite power occurs while the system is in service, each bus is auto-matica11y transferred to a separate emergency diesel power supply.

A prolonged loss of offsite power would not adversely affect the operation of the Residual Heat Removal System.

In addition, FNP has the following safeguards against RHR degradation:

A. Safeguard channels are fully independent, i.e. failure of one train will not affect output status of the other train.

B. Safeguard channels are serviced by separate inverters and trains are aligned to separate vital buses.

f C. RHR suction valves from the containment sump will not auto-matically open unless a S.I. signal in conjunction with a RWST low low level signal is received. A loss of power will not cause spurious opening of the suction valves.

[ D. RHR loop suction valve auto-closure logic at FNP is designed

! so that a RCS wide range pressure transmitter failure (high) will isolate only one train of RHR.

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Fa. James P. O'Reilly June 9, 1980 4

It is felt that the above design features and the procedural changes that are discussed in Item 1 and Item 2 satisfactorily address the concerns expressed in IE Bulletin 80-12.

If there are any further questions, please advise.

Yours very truly, F. L. Clayton, .

SWORN TO UBSCRIBED BEFORE ME THIS DAY OF JUNE, 1980.

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M Notary Fablic My commission expires h- /h"'

RWS:de cc: Mr. R. A. Thomas Mr. G. F. Trowbridge 1

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