ML19242B388

Submits Addl Facts in Response to IE Bulletin 79-06B Re Util Committing Station to Posting of Individual in Main Control Room W/Duty of Initiating Auxiliary Feedwater. Relief from Commitment Requested

ML19242B388
Person / Time
Site:	Fort Calhoun
Issue date:	05/25/1979
From:	Short T OMAHA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
NUDOCS 7908080406
Download: ML19242B388 (2)

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OMAHA, NEDRASKA 68102 a TELEPHONE 536-4000 AREA CODE 402 lby 25,1979 Mr. E. V. Seyfrit, Director U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region IV 611 Ryan Plaza Drive Guite 1000 Arlington, Texas 7o011

Reference:

Docket ?!o. 50-235 Dear "r.

Seyfrit:

The Omaha Public Power District received IE Bulletin 79-063, dated April IL,1979, requesting that a review of operational errors and sys-tem misalignments identified during the Three Mile Island incident be made and that certain information be provided on this subject relevant to the Fort Calhoan Station.

A response to the bulletin var submitted to the Commission by letter, dated April 23, 1979, which included a commitment that an individual be stationed in the main control room at the station with the sole duty of promptly i.nitiating adequate auxiliary fee.tter to the steam generators.or those transients or accidents, the consequences of which can be limited by cr.2h action.

This commitment was made pending the staff's review of tne District's response to IE Bulletin 79-06B and subsequent concurrence that Fort Calhoun's auxiliary feedwater system is adequatoly designe1 and operated without the aeed for a dedicated operator nanning the system controls.

On '4ay ll,1979, District representatf.ves met with members of the staf' in Washinctc D.

C. to discuss the Fort Calhoun auxiliary feea-watt system.

At :nis r.ee t ing, design and operational f eatures of the syste sere discussed, with emphasis on the following areas which demon-straue System adequacy; 1.

All controls for the system are located in the control room in an area easily accessible to the minimum two man crew pre-sent in the control room during operation.

2.

The system contains certain automatic features.

First, auxi-liary feedwater pumps ece automatically initiated uoon trip of the last main feedsater pu'np.

Feedwater flow to the steam Generators is then initiated automatically if a containment isolation signal (CI AS) is rt reived.

In this case, v-ves HCV-1107A/B and liCV-1108A/B open automatically to direct water to the auxiliary feedvater nozzles in the steam generators.

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~ n the absence of CIAS, auxiliary feedwater flow nust be 1;iatea by renote-manual opening of FCV-1107A/B and HCV-

. 'D" 6 N the auxiliary feedwater nozzles or by opening

.-13% to the main feedvater header and sparger when the lir feedwater pump trips.)

loss of feedwater flow incident analysis in the Fort ioun CAR assunes that auxiliary feedwater flow is not i.i t i ated for a full 12 ninutes, ' hich nrovides unple time

' '" operator action in the control room, if required.

~ r:'ormance of the auxiliary feedwater systen is easily

.nitared by flow indication and steam generator level in-

'a c n in the control room.

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.' the infortation presented in the District's response of

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' 7il, anl t v.e ir formation provided in our nectinc with the

. r eapec t f ul :

requested that the requirenent that a dedicated tationel m t the auxiliary feedwater systen controls be re-relief requested would provide for more effective use of 1

without causing any reduction in the level of safety

• .e auxiliary feedwater syster.

Sincerely, f

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Assistant General ihnacer

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