ML20085F576
| ML20085F576 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 10/25/1974 |
| From: | Sewell R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20085F577 | List: |
| References | |
| AO-23-74, NUDOCS 8308230014 | |
| Download: ML20085F576 (2) | |
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General OHices 212 Wee,t Machigan Avenue. Jackson Mic higan 49201. Area Code S17 7HH-OS50 October 25, 1974
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Directorate of Licensing Re:
Docket 50-255 US Atomic Energy Commission License DPR-20 Washington, DC 20545 Palisades Plant - AO-23-74 Gentlemen:
Attached is Abnormal Occurrence Report A0-23-Th which covers our finding of improper setting of the thermal margin / low-pressure trip set point. This abnormal occurrence was discovered during a review of these set points. The plant was in the hot standby condi-tion during this occurrence. No limits were exceeded.
Yours very truly, Ralph B. Sewell (Signed)
DAB /mel Ralph B. Sewell Nuclear Licensing Administrator CC: JGKeppler, USAEC g& D. 3'S' 8308230014 741025 s,<c< h uf' PDR ADOCK 05000255 S
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COPFSENT REGIQ
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('s ABNORMAL OCCURRENCE REPORT Palisades Plant 1.
Report Number:
A0-74-23, Docket 50-255 2.
a.
Report Date: October 25, 1974 b.
Occurrence Date: September 6, 1974 (discovered October 16,1974).
3.
Facility: Palisades Plant, Covert, Michigan.
h.
Identification of Occurrence: The three-primary coolant pump (PCP) mode of operation was used without having the minimum thermal margin /
low-pressure trip set point raised to the Technical Specifications limit.
5.
Conditions Prior to Occurrence: The reactor was critical in the hot standby condition.
6.
Description of Occurrence: On September 6, 1974 at Ih51 the PCP operating configuration was changed from four-pump to three-pump without raising the minimum thermal margin / low-pressure trip set point to above 1750 psia as specified in the Technical Specifica-tions.
7 Apparent Cause: At the ti=e of the occurrence, the operators had no obvious mechanism to remind them that the thermal margin / low-pressure trip set point should be changed. Some such mechanism should have been provided so that, especially at such times as plant start-up, an obvious reminder is present to prevent this oversight from occurring.
8.
Analysis of Occurrence: The operation of the plant in this mode -
three-PCP - was limited to the hot standty condition. Since the thermal margin / low-pressure trip is used to prevent DNB, no safety significance can be attributed to this particular incident as there was no power operation in the three-pump mode.
9.
Corrective Action: Corrective action recommended by the Plant Review Committee follows:
Provide a tag near the flow trip point selector switch stating a.
that thermal margin / low-pressure trip set point must be changed prior to going to the three-PCP or two-PCP mode of operation.
b.
Initiate a change to Procedure Bl.0 to incorporate the same caution as above.
10.
Failure Data: Not applicable.