ML19253B618

From kanterella
Jump to navigation Jump to search
Forwards IE Info Notice 79-25, Reactor Trips at Turkey Point Units 3 & 4. No Action Required
ML19253B618
Person / Time
Site: 05000363
Issue date: 10/01/1979
From: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To: Finfrock I
JERSEY CENTRAL POWER & LIGHT CO.
References
NUDOCS 7910160527
Download: ML19253B618 (1)


Text

,

Tac:-

ga anco y

'o, UNITED STATES S,

g NUCLEAR REGULATORY COMMISSION

{

REGION 1 3'

.L [E 0,

631 PARK AVENUE

,e KING OF PRUSSIA, PENNSYt.VANIA 19406 Docket No. 50-363 007 1 1973 Jersey Central Power & Light Company ATTN:

Mr. I. R. Finfrock, Jr.

Vice President 260 Cherry Hill Road Parsippany, New Jersey 07054 Gentlemen:

This Information Notice is provided as an early notification of a possibly significant matter. It is expected that recipients will review the information for possible applicability to their facilities.

No specific action or response is requested at this time.

If further NRC evaluations se indicate, an IE Circular, Bulletin, or NRR Generic Letter will be issued to recommend or request specific licensee actions. If you have questions regarding the matter, please contact the Director of the appropriate NRC Regional Office.

Sincerely, M4 oyce H. Grier

' Director

Enclosures:

1.

IE Information Notice No. 79-25 2.

List of IE Information Notices 1ssued in the Last Six Months cc w/encis:

M. K. Pastor, Project Manager 1150 305

  1. 9.1 0 3 e o s p y 9

ENCLOSURE 1 Accession No.: 7908220125 SSINS No.: 6870 t,NITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.

20555 IE Information Notice 79-25 Date:

October 1, 1979 Page 1

' 2 REACTOR TRIPS AT TURKEY POINT UNITS 3 AND 4

Background

On August 3, Turkey Point Units 3 and 4 tripped while operating at full power.

A voltage spike on a second protection channel caused Unit 4 to trip during surveillance testing on the reactor protection system.

This resulted ir a loss of offsite power and subsequent shedding of non-essential loads.

Unit 3 tripped as the result of high coolant pressure caused by a turbine runback.

Discu:;sion While performing a periodic test on channel "C" of the T-Average and Delta T Protection Channels, a spurious signal on channel "A" completed a 2 out of 3 trip logic tripping Unit 4.

This resulted in a loss of offsite power condi-tion for Unit 4.

At this time, the Unit 4 startup transformer was out of service due to performance of periodic maintenance.

This condition caused the initiation of the emergency diesel generator load sequencer which resulted in the shedding of non-vital loads.

Among the non-vital loads shed were those on Motor Control Center (MCC) "D" which is common to both units.

Since the Rod Position Indicatko System for both units is powered by the non-vital portion of MCC-0, a turbine runback on Unit 3 was initiated upon loss of rod position indication.

This resulted in a reactor trip on high pressurizer pressure.

At the time, neither of the two pressurizer spray valves was avail-able.

One was considered inoperable prior to the transient and the other, temporarily powered by the non-vital portion of MCC-D, had become unavailable earlier as a consequence of the Unit 4 trip.

A subsequent review disclosed inadequacies in the administrative controls over the correction of operational problems exhibited by spray valve PCV-3-455B.

The original Hagan controller for spray valve PCV-3-455B had been disconnected.

It was replaced by another manual controller which was plugged into the valve control circuit and which had been taped to the top of a console in the main control room.

The actual installation of the manual controller was not per-formed uader established guidelines.

Additionally, no temporary procedure had been issued to ensure consistent under


'+iaa=1 control of this unusual component conf DUPLICATE DOCUMENT Entire document previously entered into system under:

}

ANO h

h No. of pages:

.