Tyler J. Winter



The Babcock and Wilcox Company

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

Date: February 9, 1978


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 Toledo during which high pressure injection was prematurely terminated. If this situation occurred in a reactor operating at full power it could easily result in that core uncovery and fuel damage could occur. This is a serious matter which demands our prompt attention and correction




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