ML18065B129
| ML18065B129 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 12/19/1997 |
| From: | Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9801020084 | |
| Download: ML18065B129 (5) | |
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I A CMS Energy Company December 19, 1997 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT TIJOllUI* c. Bordlae Manager Licensing CORRECTION TO CONSUMERS ENERGY COMPANY DECEMBER 18, 1997 LETTER ENTITLED "CORRECTIVE ACTION AND COMMITMENT RELATED TO CONSUMERS ENERGY RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING CABLE AMPACITY ADJUSTMENT METHODOLOGY" In our December 18, 1997, submittal related to a corrective action and a commitment regarding cable ampacity adjustment methodology, text was inadvertently omitted from the cover letter. The third sentence of the third paragraph should have read as follows:
"The commitment stated that these three cables would be replaced prior to startup from the 1998 refueling outage." The December 18, 1997 letter is reprinted below in its entirety with the correction.
In response to a May 27, 1997, NRC request for additional information regarding the Palisades cable ampacity adjustment methodology, Consumers Energy Company submitted, on July 10, 1997, a response identifying a corrective action and making a specific commitment to eliminate calculated cable tray overheating. This letter informs the NRC of completion of the corrective action, and of withdrawal of the specified
- commitmenl ----- - *-
In the July 10, 1997, response, Consumers Energy described a corrective action to reduce the calculated temperature within a cable tray at the plant. In response to NRC Question 4(c}, Consumers Energy described a corrective action planned to reduce the calculated temperature within tray XP600 by raising the tray cover slightly to allow air to
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2 circulate and reduce tray temperature. On November 10, 1997, this action was taken as cover stand-off clips were installed which permanently raised the tray XP600 cover.
The July 10, 1997 commitment also responded to NRC question 4(c). Consumers Energy committed to replace the two 75°C designated cables in tray XK456 evaluated to have a remaining life of four years, and to replace the 90°C designated cable in tray XK456 which was driving the overall calculated tray temperature above the 75°C value. The commitment stated that these three cables would be replaced prior to startup from the 1998 refueling outage. The commitment was made in order to extend the remaining life of cables in tray XK456. As described in further detail in the attachment to this letter, additional evaluation has been performed which cites specific as-built configurations and a recent cable reroute serving to eliminate calculated cable tray overheating. Therefore, the three cables in tray XK456 do not need to be replaced. We hereby withdraw our commitment to replace the three cables.
SUMMARY
OF COMMITMENTS This letter contains no* new commitments and Withdraws the July 10, 1997 commitment which is restated below.
In order to extend the remaining life of cables in tray XK456, the two 75°C cables evaluated to have a remaining life of four years will be replaced, as will the 90°C cable which is driving the overall calculated tray temperature above the 75°C value. These three cables will be replaced prior to startup from the 1998 refueling outage.
Thomas C. Berdine Manager, Licensing CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades Attachment
ATTACHMENT CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 BASIS FOR WITHDRAWAL OF JULY 10, 1997 COMMITMENT TO REPLACE THREE CABLES IN CABLE TRAY XK456 PALISADES PLANT 2 Pages
- .J BASIS F.OR WITHDRAWAL OF JULY 10, 1997 COMMITMENT TO REPLACE THREE CABLES IN CABLE TRAY XK456 PALISADES PLANT To extend the remaining life of cables in tray XK456, Consumers Energy Company committed on July 10, 1997 to replace the two 75°C designated cables in tray XK456 evaluated to have a remaining life of four years, and to replace the 90°C designated cable in tray XK456 which was driving the overall calculated tray temperature above the 75°C value. The commitment stated that these three cables would be replaced prior to startup from the 1998 refueling outage. The paragraphs below provide the results of additional evaluation which has determined that these three cables need not be replaced.
Tray XK456 cable PBS8/Y230A/1, which feeds a circuit breaker panel in the Critical Functions Monitoring System trailer, was physically located and found to be a 90°C rated cable. This cable was incorrectly designated as a 75°C cable in the plant's circuit and raceway schedule, and was one of the two cables evaluated to have a remaining life of only four years. Revision of the circuit and raceway schedule will be made to reflect the cable's 90°C designation. Replacement of this cable is not required nor will be made.
Cable 808/Z211/1, which feeds containment lighting transformer X-37, was scheduled to have the cable section in tray XK456 replaced by cable rated at 90°C. This cable was the second of two XK456 tray cables evaluated to have a remaining life of only four years.
When the cable was physically located in the tray, it was found to enter tray XK456 at the point where cable CONT-1-2/L258/2 (the main source of heat for tray XK456, see paragraph below) exited the tr(;!y. At their closest proximity, the two cable were 3/4" apart where they crossed at an approximate 90° angle in open air. Cables 808/Z211/1 and CONT-1-2/L258/2 have never occupied the same part of cable tray XK456. Therefore, cable 808/Z211/1 has never been subjected to the heat predicted to be generated by cable CONT-1-2/L258/2 if they had been running parallel in the same cable mass. The thermal model for tray XK456 predicts a maximum temperature of 72.6°C when cable CONT-1-2/L258/2 is not in the tray. Based on this and the walkdown information, there is no need to replace the section of cable 808/Z211 /1, and the cable section will not be*
replaced. *The accompanying sketch serves to visualize the routing.
Cable CONT-1-2/L25B/2, which was the main source of heat in tray XK456, was to be replaced with a larger size cable to reduce predicted heating. Of the entire route of cable CONT-1-2/L258/2, only tray XK456 was predicted to exceed 75°C due to tray fill. This, along with the difficulty in accessing the entire cable route, led Consumers Energy to conclude thatrerouting the_ caple o~t of tray XK456, versus cable replacement, was a more cost-effective solution. As a result, Consumers Energy rerouted cable CONT..:1-2/L25B/2 out of tray XK456 and into new conduit X8501. This work was completed on November 4, 1997. Cable CONT-1-2/L25B/2 will not be replaced.
1
BASIS FOR WITHDRAWAL OF JULY 10, 1997 COMMITMENT TO REPLACE THREE CABLES IN CABLE TRAY XK456 PALISADES PLANT Top View XK4S6 Side View CONT-1-2/L25B/2 XK456 Trays XP130 &
XK130 2
B08/Z211/1 3 cable bundle N