ML20249C801

PNO-76-204:on 761130 & 1201,three Inadvertent Safety Injections Occurred.Reactor in Mode 3 During Each Occurrence.State of Nj Informed

ML20249C801
Person / Time
Site:	Salem
Issue date:	12/02/1976
From:	Dreher F, Roy G, Thompson D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-76-204, NUDOCS 9807010215
Download: ML20249C801 (2)

Text

_ _ _ _ _ _ _. _ _ _ _ _ _ _

fpf Glb'AT-Wf y,

W f fg, /Lo

./-

PRELIMINARY NOTIFICATION December 2, 1976 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-76-204 This preliminary notification constitutes EARLY notice of an event of POSSIBLE 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.

Facility:

Salem Unit No. 1 (DN 50-272)

Subject:

INADVERTENT SAFETY INJECTIONS Three inadvertent safety injections (sis) occurred at 10:39 p.m., 11:01 p.m.,

November 30 and 2:39 a.m., December 1, 1976. The reactor was in Mode 3 (hot shutdown) during each occurrence.

Initial criticality has not yet been achieved.

The first two sis were initiated by low Reactor Coolant System (RCS) average temperature (Tav) in conjunction with a spurious high steam flow signal in steam line 14. During these sis the following occurred:

1.

SI flow lasted for 3 minutes (First SI) and 2 minutes (Second SI).

2.

The reactor trip breakers did not open and the "B" SI Train valves did not actuate in either SI.

The third SI was initiated by low steam pressure in steam line 14 compared to the other lines. There was no SI flow because the boron injection tank valves were closed to' adjust boron concentrations due to the first two sis. Reactor trip breskers and valves in both SI trains operated properly.

The licensee's preliminary evaluations indicate the following:

1.

The reactor trip breakers and "B" SI train did not respond in the first two sis, probably because the duration of the actuation signal.gf was not sufficient to drop the bistables.

~d d 2.

The steer. safety valve in steam line 14 relieved below its setpoint due to an improper setting.

A Region I inspector is on site reviewing the occurrences.

CONTINUE s

I 9007010215 761202 PDR I&E I

PNO-76-204 PDR i

L.____.______.

]

~

~

Pcge 2 December 2, 1976 Continued PNO-76-204 Media interest is expected because of close attention given to occurrences at Salem. The State of New Jersey has been informed. A press release is not planned.

NRC, Region I, (Philadelphia) received notification of this occurrence by telephone from the inspector onsite at 11:15 a.m., December 1, 1976. The information is current as of 3:00 p.m., December 1, 1976.

Contact:

FADreher, IE x27261 GWRoy, IE x27261 DThompson, IE x27541 Distribution:

Chairman Rowden Commissioner Mason S. J. Chilk, SECY Commissioner Gilinsky C. C. Kammerer, CA G. F. Murphy, JCAE Commissioner Kennedy L. V. Gossick, EDO K. R. Chapman, NMSS R. G. Ryan, OSP S. H. Hanauer, EDO E. Volgenau, OIE J. A. Harris, PA B. C. Rusche, NRR H. K. Shapar, ELD T. J. McTiernan, OIA Transmitted: PBldg

H St

HNBB Luge PRELIMINARY NOTIFICATION

.i m'

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. _ _ _ _ _ _ _ _