Tyler J. Winter
Power Generation Group
To: Jim Taylor, Manager, Licensing
From: Bert M. Dunn, Manager ECCS Analysis (2138)
Subj: Operator Response to LOCA and Interruption of High Pressure Injection
This memo addresses the concern that we have not supplied reactor operators with sufficient information about recovery from LOCA [Loss of coolant accidents]. The following rule is based on an attempt to allow termination of high pressure injection only when the reactor coolant system is in a subcooled state and the pressurizer indicates a normal level.
I recommend that that the operating procedures be written to allow termination of high pressure injection under the following conditions:
1. Low pressure injection has been actuated and is flowing at a rate in excess of high pressure injection capability and that this situation has been stable for at least ten minutes.
2. And system pressure has recovered to a normal operation pressure between
2200 and 2250 psig and that system temperature within the hot leg is also at
or below a temperature of 630 F°.
This concern rose out of a recent incident in