ML040280397
| ML040280397 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 01/14/2004 |
| From: | Domonique Malone Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML040280397 (2) | |
Text
NCme Palisades Nuclear Plant Operated by Nuclear Management Company, LLC January 14, 2004 Technical Specification 5.6.6 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Palisades Nuclear Plant Docket 50-255 License No. DPR-20 Notification Of Inoperability Of One Core Exit Temperature Channel Palisades Technical Specifications (TS), Table 3.3.7-1, Item 19, requires that four channels of core exit temperature be operable in reactor quadrant four in Modes 1, 2, and 3. TS 5.6.6, in conjunction with TS 3.3.7.B.1, requires that a report be submitted to the NRC within 14 days when one core exit temperature channel is inoperable and not restored within 30 days. The report is to contain an outline of the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the channel to operable status. The required report is attached.
Summary of Commitments This letter contains one new commitment and no revisions to existing commitments.
The new commitment is:
Full compliance with TS Table 3.3.7-1, Item 19, for core exit temperature in quadrant four, will be restored prior to startup from the next refueling outage.
Daniel J. Malone Site Vice President, Palisades Nuclear Plant Nuclear Management Company, LLC Enclosure (1)
CC Administrator, Region Ill, USNRC DI Project Manager, Palisades, USNRC U
Resident Inspector, Palisades, USNRC 27780 Blue Star Memorial Highway
- Covert, Michigan 49043-9530 Telephone: 269.764.2000
ENCLOSURE I NOTIFICATION OF INOPERABILITY OF ONE CORE EXIT TEMPERATURE CHANNEL CORE EXIT THERMOCOUPLE DESIGN Core Exit Thermocouples (CETs) are used for post accident monitoring of core exit temperature. Four environmentally qualified CETs in each reactor quadrant are required per Technical Specification Table 3.3.7-1, Items 16 through 19 (a total of 16 qualified CETs are required). The CETs provide indication only and are not used for reactor control. Loss of indication from any one of the qualified CETs results in failure to meet the requirements of Technical Specification Table 3.3.7-1.
CAUSE OF INOPERABILITY On December 7, 2003, qualified CET-36 was declared inoperable due to erratic indication. The apparent cause of the erratic signal is a poor connection in the circuit that is subject to the build up of oxides that eventually interrupted the signal. The most probable location for the intermittent open-circuit fault is the connection at the reactor vessel head. This location is inaccessible during plant operation.
PREPLANNED ALTERNATE METHOD OF MONITORING Plant procedures and the plant process computer use the average of qualified CETs as the monitored parameter to ensure adequate core cooling in a post-accident scenario.
CET-36 is no longer included in the average. Fifteen qualified CETs remain operable as the primary means for monitoring core exit temperature.
SCHEDULE FOR RETURN TO SERVICE Full compliance with TS Table 3.3.7-1, Item 19, for core exit temperature in quadrant four, will be restored prior to startup from the next refueling outage. The faulted connection will be corrected by replacement of the CET, and/or replacement of the associated qualified instrument cable as necessary. Alternatively, if replacement of these components is not feasible, the qualified cable may be routed to another CET within reactor quadrant four to meet the requirements of Technical Specification Table 3.3.7-1, Item 19.
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