ML20248L029

PNO-78-079B:supplements PNO 78-79A .Informs That Addl Analyses Being Conducted by B&W.Licensee Reported That Operators Have Been Stationed at HPI Crossover Piping to Promptly Realign Sys for 2 Flow Paths Upon Break Detection

ML20248L029
Person / Time
Site:	Oconee
Issue date:	04/20/1978
From:	Klingler G, Nolan F, Sniezek J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-78-079B, PNO-78-79B, NUDOCS 9806100382
Download: ML20248L029 (1)

Text

( f 0b'h'Ilkf ~}

_ PRELIMINARY NOTIFICATION [] , ,

~ April 20, 1978 /

PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-78-79B V

This preliminary notification constitutes EARLY notice of an event of POSSI 3LE safety or public interest significance. The information presented is as initially received without verification or evaluation and is basically all that is known by IE staff on this date.

FAC!LITY: Duke Power Company Oconee, Unit Nos.1, 2 and 3 Docket Numbers 50-269, 50-270 and 50-287 Oconee County, South Cr.rolina

SUBJECT:

ERROR IN SMALL BREAK ANALYSIS OF REACTOR COOLANT SYSTEM This supplements PN0 78-79A dated April 14.

The licensee reported that the ongoing safety analysis by B&W for a small break in the reactor coolant system identified a further change in the size of the worst case break as discussed in PNO-78-79 and 79A. The jJ reanalysis revealed that a 0.1 square foot break in the reactor coolant .

pump discharge piping reduced the time available for operator actions M

~

from twenty-five minutes to ten minutes. This analysis assumes only one

,  ; high pressure injection (HPI) flow path is available, and the core flood n

( ~

/

(CF) and low pressure injection (LPI) systems do not function properly due to high reactor coolant system pressure. F/ l Additional analyses are being conducted by B&W. The licensee reported that operators have been stationed at the HPI crossover piping to promptly kb '

realign the system for two flow paths upon detection of a break. The problem is being evaluated by NRR and is reported to be generic to all B&W facilities.

There has been no media interest. A news release is not planned by the licensee nor NRC. The State of South Carolina has been notified.

Region II (Atlanta) received notification of this occurrence by telephone from the licensee management at 6:15 p.m. on April 19. This information is current as of 10:30 a.m. on April 20. ,

l

Contact:

GKlingler, IE x28019 FNolan, IE x28019 JSniezek, IE x28019 oE Distribu' tion : Transmitted H St //.' N g

Chairman Hendrie Commissioner Bradford "

Commissioner Kennedy S. J. Chilk, SECY C. C. Kammerer, CA F, Commissioner Gilinsky (For Distribution) hh ' Transmitted: MNBB // ' T L. V. Gossick, ED0 P Bldg //.*

E. G. Case, NRR E. Volgenau Region g IE

/A nooM E S. H. Hanauer, EDO J. J. Fouchard, PA SSBldg//*\ (MAIL) n.a. R. Hartfield, MIPC C. V. Smith, NMSS T. J. McTiernan, 01A R. G. Ryan, OSP ,n R. Minogue, SD H. K. Shspar, ELD , m e /1 o DDCITMTMADV MATTCTf'ATinu