ML20039C162

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Tech Spec Change Request 91 for Amend to License DPR-72 Re Proposed Operation of Less than 40% During Certain, Operations W/Reactor Coolant Pump Power Monitor Trip Function Bypassed
ML20039C162
Person / Time
Site: Crystal River Duke Energy icon.png
Issue date: 12/22/1981
From:
FLORIDA POWER CORP.
To:
Shared Package
ML20039C161 List:
References
3F-1281-34, TAC-47464, NUDOCS 8112280518
Download: ML20039C162 (1)


Text

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TECHNICAL SPECIFICATION CHANGE REQUEST NO. 91 Replace pages 3/4 3-2 and 3/4 3-3 with pages 3/4 3-2 and 3-3, provided.

PROPOSED CHANGE This change will allow operation of the unit at less than 40% Full Power during certain operations (i.e., starting reactor coolant pumps, transformer switchover, etc.) with the reactor coolan; pump power monitor trip function bypassed.

REASON FOR PROPOSED CHANGE Florida Power Corporation installed a reactor coolant pump power monitoring system as part of our recent power level increase. On three occasions (twice in Mode 3 during startup and once in Mode 1 during a controlled shutdown), the pump power monitor trip has caused a reactor trip. Testing in Mode 3 indicated that the monitored parameter (bus power in watts) did in fact go through a very short-lived (<1 sec.) transient when energizing an idle reactor coolant pump. It is hypothesized that a similar transient occurred during the switchover from the unit auxiliary to the start-up transformer, and that it could occur when deenergizing an active reactor coolant pump.

These trips are unnecessary and are, therefore, counterproductive to overall unit safety.

SAFETY EVALUATION Transients associated with reactor trips are acceptable only when they terminate more serious or potentially serious events. Spurious trips, such as these pump power monitor trips are, therefore, not acceptable.

The pump power monitors are designed to terminate events associated with locked rotor accidents at full power. During operation at less than full power (e.g., less than 40%

Full Power), the pump power monitors are not essential to insure meeting acceptance criteria associated with transient response .(DNBR, etc.). They simply serve as alternate (either anticipatory or backup, depending on the scenario) trips. Therefore, operation with the trip function bypassed is consistent with safe operation.

8112280518 811222 PDR ADOCK 05000302 PDR p

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