ML18082A652
| ML18082A652 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 06/09/1980 |
| From: | Schneider F Public Service Enterprise Group |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-12, NUDOCS 8006300490 | |
| Download: ML18082A652 (4) | |
Text
- ~~~
---:~
~-~*::...
Frederick W. Schneider Vice President Public Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 201/430-7373 Production June 9, 1980 Mr. Boyce H. Grier, Director Off ice of Inspection and Enforcement USNRC Region I 631 Park Avenue King of Prussia, Pennsylvania 19406
==Dear Mr
- Grier:==
NRC IE BULLETIN NO. 80-12, DECAY HEAT REMOVAL SYSTEM OPERABILITY SALEM GENERATING STATION UNIT NOS. l AND 2 DOCKET NOS. 50-272 AND 50-311 Pursuant to the subject bulletin's required actions, we hereby submit the following response:
Item l We have reviewed.the circumstances and sequences of events which caused the loss of decay heat removal capabilities at the Davis-Besse Plant.
The problem at Davis-Besse appears to have been aggravated by.design provisions in the protection system and. engineered safeguards.
This is a B&W design plant and some of their design features are not applicable to the Salem Westinghouse* design.
Item 2 We have experienced five separate instances where decay heat removal capabilities were affected.
Thes*e events are described in Licensee Event Reports 76-04/03L (September 28, 1976), 77-69/03L (November 25, 1977), and 79-59/03L (March 27, 1980).
The time out-of-service for the events ranged from two minutes to thirty-four minutes.
Although a loss of decay heat removal can be initiated at Salem Generat-ing Station through a variety of causes as described in the Licensee Event Reports listed, by electrical fault on the pumps, or by pressure in-terlock circuitry for RHR suction valves from the reactor coolant system failure, the particular sequence of events at Davis-Besse which resulted in automatic transfer of suction to the empty containment sump will not occur at Salem.
(See Item 3)
/)) u
~---------
B. H. Grier
"'." 2 -
6-9-80 Item 3 The Salem design does not preclude the initiation of a loss of decay heat removal event.
It can be initiated by a variety of causes as dis-cussed in Item 2.
However, the Salem design has sufficient redundancy and diversity to preclude decay heat removal degradation.
There are
_two RHR pumps, four steam generators and three* auxiljary feedwater pumps (two motor driven and one turbine driven).
These pumps are safety grade and powered from the vital buses (supplied by the diesel-generators).
The instrumentation power sources are supplied by the.vital buses through inverters with battery backup *. The controls for decay heat removal through the steam generators can be done locally as well as from the control room.
- There is only one suction line from the reactor coolant system for RHR cooling during shutdown.
This line has two motor-operated valves (RHl a.nd RH2) which are provided with safety grade pressure i!lterlocks to preclude overpressurizati.on.
Each valve is controlled by a separate pressure transmitter.
Upon loss of instrument power (115V) to the cir-cuit the valves will go closed causing a loss of decay heat removal capability event.
The valve can be reopened from the motor control center (230V) by jumpering the interlock circuit.
The pressure trans-mitters for the circuitry are safety grade including environmental and
- seismic qualification.
The reliability of the circuitry and power sources should not result in a high frequency of such events.
- However, although* not redundant, there is action that can be taken by the oper-ator to restore decay heat removal capability and, in addition, the steam generators and auxiliary feedwater system can be utilized.
Items 4 through 7 we are presently evaluating methods for complying with NRC requirements for automating portions of the switchover to cold leg recir.culation dur-ing LOCA recovery.
This automatic switchover directly impacts the RHR system and has caused additional considerations to be taken into account in our review of procedures.
The required evaluation will be developed and presented to the NRC by July 18, 1980.
It is expected that all pro-cedures relating to decay heat removal redundancy and diversity will be reviewed and modified prior to that date.
Our existing Emergency In-struction I--4.22, "Loss of Residual Heat Removal Shutdown Cooling" ade-quately covers a loss of RHR event but will also be upgraded, if neces-sary, prior to July 18, 1980.
B. H. Grier 3 -
6-9-80 We feel that Salem presently has sufficient redundancy and diversity of design and has adequate procedures for dealj~g with loss of decay heat removal capability events.
If you have any further questions~ we will be pleased to discuss t~em with you.
Sincerely, ~
STATE OF NEW JERSEY )
)
SS:
COUNTY OF ESSEX
)
FREDERICK w. SCHNEIDER, being duly sworn according to law deposes and says:
I am a Vice President of Public Service Electric and Gas Company, and as such, I signed the letter dated June 9, 1980, to Mr. Boyce H. Grier, Director, NRC Office of Inspection and Enforcement, Region I, in partial response to NRC Bulletin No. 80-12 "Decay Heat Removal System Operability."
The matters set forth ip said response letter are true to the best of my knowledge, information, and belief.
Subscribed and sworn to before me this '/ t) d f
...J--v ""'a
' 1980
-"--"-~- ay o __ ___... _____________ _
=
Notary ~ublic of New Jersey My Conunission expires on d c'/. 11
/ ?' ?"3