ML19320C329

Significant Deficiency Repts 369/80-07 & 370/80-06 Re Centrifugal Charging Pump Operation Following Secondary Side High Energy Line Rupture.Potential Exists for Inadequate Min Flow W/Damage to Pumps

ML19320C329
Person / Time
Site:	Mcguire, McGuire
Issue date:	07/07/1980
From:	DUKE POWER CO.
To:
Shared Package
ML19320C325	List: ML19320C324 ML19320C329
References
NUDOCS 8007160663
Download: ML19320C329 (1)

Text

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Duka Power Comp 1ny McGuire Nuclear Station G Units 1 & 2 Report Number: SD-369/80-07, 370/80-06 Report Date: July 7, 1980 Facility: McGui re Nuclear Station, Uni ts 1 & 2 Re fe rence : Westinghouse letter NS-TMA-2245, May 8,1980, from T. M. Anderson m V. Stello (copy attached)

Description of Deficiency:

See referenced Westinghouse letter NS-THA-2245. Duke Power Company has performed a specific analysis for the McGuire Plant which indicates that the potential does exist for inadequate minimum flow with consequential damage to one or both centrifugal charging pumps following a secondary side high erergy line rupture.

Analysis of Safety lmolications:

Inadequate minimum flow through the centrifugal charging pumps may result in degraded performance or loss of function of one or both pumps. This in turn may adversely impact long-term recovery operations for the initiating event and is not permitted by design criteria.

Corrective Action:

Westinghouse Electric Company is currently studying this problem to determine an appropriate permanent solution. Westinghouse has recommended two possible interim solutions to the problem as described in the referenced letter NS-TMA-2245, however, Duke Power Company is awaiting confirmed analytical results supporting acceptability of those solutions with regard to impact on consequences of various accidents which initiate safety injection and are sensitive to centrifugal charging pump flow delivery. A report wiil be filed by August 12, 1980 detailing both interim and permanent corrective actions.

s 800 71 o n gg3

1 Westinghause Water Reactor metar ween civis:en Electric Corporation Divisions  %

Pmsspknnsylvam m:0 May 8, 1980 NS-TMA-2245

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Mr. V. Stello, Director ,

Office of Inspection and Enforcement l U. S. Nuclear Regulatory Cc=aission -

1717 H Street .

l Washington, D. C. 20555

Subject:

Centrifugal Charging Pump Operation Following Secondary Side High Energy Line Rupture

Dear Mr. Stello:

This letter is to confim the telephone conversation of May 8,1980 between Westinghouse and Mr. Ed Blackwccd of Division of Reactor Operatiens Inspecticn, Office of Inscection and Enforcement, regarding notification made pursuant to Title 10 CFR Part 21. -  ;

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'A review of the Westinghouse Safety Injection (SI) Termination Criteria l following a sec:ndary side high energy line rupture (feedline or steamline nJpture.at hich initial power levels) nas revealed a potential for c:nse-

• quential damage of one or more centrifugal enarging pumos (CCPs) before the SI tennination criteria are satisfied and CCP operation teminated.

Such m w m W 1 damace cay adversely it:act long-term recovery coeration_s for the initiating event anc is nos peraunec oy cesign criteria. This

'oncern C exists for piants wnica utilize tne CCPs as 5:ergETrcy Cm e Cooling System (ECCS) puros, wnere the CCPs are aunccatically started, anc wnere the CCP minificw isolatien valves are automatically isolated upon safety injecticn initiation. Attacn=ent A identifies plants potentially subject t: tnis concern. A su=ary of the concern and recc=encations follcw.

Following a secondary side high energy line ructure and' associ$ ted reactor trip, Reacter Ccolant System (RCS) pressure and temperature in1tlally decrease.

Safety injection is actuated and the CCPs start to increase RCS inventory.

Reactor Coolant System cressure and te cerature subsecuently increase due to the loss of secencary inventory, steamline anc feedline isolation, RCS inventory addition anc reactor core cecay heat generatien. The accident scenario may vary with rupture si:e and s ecific plant design, but it will develop into a RCS neatup transient witn accc=panying increase in RCS cressure.

m - _ ;aw n m ,c w COW p1Mg??Ey@WSWM5. v @E@%ger-operated2350 psia. relief Althougnvalves there signed as safety-related equip- -

DUPLICATE DOCUMENT r loss of offsite powe'r,

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