ML18047A685

Forwards, Sep,High Energy Line Breaks Inside Containment, Palisades Nuclear Station,Phase IV Summary of Results, Revision 0. Rept Incorporates Results of Fracture Mechanics Analysis

ML18047A685
Person / Time
Site:	Palisades
Issue date:	12/09/1982
From:	Toner K EDS NUCLEAR, INC.
To:	Crutchfield D Office of Nuclear Reactor Regulation
Shared Package
ML18047A686	List: ML18047A685 ML18047A687
References
TASK-03-05.A, TASK-3-5.A, TASK-RR NUDOCS 8212130224
Download: ML18047A685 (2)

Text

consumers Power company General Offices: 1945 West Parnell Road, Jackson, Ml 49201 * (517) 788-0550 December 9, 1982 Dennis M Crutchfield, Chief Operating Reactor Branch No 5 Nuclear Reactor Regulation US Nuclear Regulatory Commisssion Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT - SEP TOPIC III~5.A, EFFECTS OF PIPE BREAK ON STRUCTURES, SYSTEMS AND COMPONENTS INSIDE CONTAINMENT Consumers Power Company letter dated August 16, 1982 submitted a draft report by EDS N~clear, Inc. entitled "Systematic Evaluation Program, High Energy Line Break Inside Containment, Palisades Nuclear Station, Phase IV Summary of Results, Rev. B." As described in this report, the number of unresolved break locations was reduced to thirteen. However, as indicated in our August 16, 1982 letter, *this report was incomplete due to the ongoing fracture mechanics evaluations of the remaining 13 break locations and the fact that Consumers Power Company comments of Phase IV had not been incorporated.

The attached report by EDS Nuclear, Inc. entitled "Systematic Evaluation Program, High Energy Line Breaks Inside Containment, Palisades Nuclear "

Station, Phase IV Summary of Results, Rev. O," incorporates Consumers Power Company comments, provides the results of the fracture mechanics analysis, and describes the results of high energy line break for all postulated breaks on the 30 high energy lines. All but one high energy line break have been resolved.. The remaining postulated condition in the 3 inch pressurizer spray line is a pipe whip interaction with a cable tray containing power cables to hydrogen recombiner M69B.

The postulated break of the pressurizer spray line is assumed as a double ended guillotine rupture that results in the whipping pipe striking the cable tray approximately 20-feet from the pipe. A preliminary leak before break fracture mechanics analysis shows that a stable 90° crack with a leak rate of approximately 0.1 gpm. A leak rate of this magnitude is probably too small to be readily detectable by present in-plant leak detection equipment. However, the leak would be detected in the daily calculation of the primary coolant inventory. Based upon the preliminary deterministic fractu;re mechanics analysis, Consumers Power Company believes that the possibility of the 3-inch pressurizer spray line break resulting in a pipe whip is unlikely. Therefore, the need to modify the plant to add whip restraints or a barrier to protect the target cable tray is unwarrant~d. ¥urthermore, a modification to add local leak detection_to monitor one.weld is also not warranted. The weld 8212130224 821209 PDR ADOCK 05000255 P PDR (\, I oclLoL-uuu~a-~LuL t'\ 1~

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DMCrutchfield, Chief 2 ***_-;- ~- ,.

Palisades Plant SEP TOPIC III-5.A December 9, 1982 associated with the break location is presently examined to ASME Section XI Glass 1 requirements and is scheduled for inspection during the 1985 refueling outage.

The postulated break has been listed as unresolved in the enclosed evaluation due to the severance of the power cables to the hydrogen recombiner coupled with a single failure of the other diesel generator supplying power to the redundant hydrogen recombiner. Because the recombiner is not an active component, a single failure of it soiely need not be considered.

Following a small break LOCA of the 3-inch pressurizer spray line, the hydrogen recombiner is not needed until a 2% hydrogen volume concentration is reached in containment. For comparative purposes calculations performed for the Palisades containment show a 2% volume percent of hydrogen volume

• concentration is not reached until 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> have ellapes following a DBA.

Plant operating procedure ONP-22 requires a hydrogen recombiner. to be energized by the time hydrogen concentration has reached 2%. If at that time the recombiner is found to be inoperative, due to cable severence, there would be adequate time available to restore power to the redundant hydrogen recombiner before a combustible mixture of 4% is reached at about 350 hours0.00405 days <br />0.0972 hours <br />5.787037e-4 weeks <br />1.33175e-4 months <br />.

It is reasonable to .assume that given this time frame of 350 hours0.00405 days <br />0.0972 hours <br />5.787037e-4 weeks <br />1.33175e-4 months <br /> associated with a DBA, the diesel generator malfunction will be corrected or offsite power will be restored.

In summary, Consumers Power Company believes the need to modify the plant as a result of postulated rupture resulting in a leak in the 3-inch pressurizer spray line is unwarranted. Consumers Power Company considers the inservice inspection of the particular weld location to be adequate resolution of the

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issue. Furthermore the loss of a ,hydrogen recombiner as a result of postulated small break LOCA would not degrade the plant's ability to mitigate the effects of the accident. Finally, Consumers Power Company believes t~at this submittal constitutes completion of SEP Topic III-5.A.

Kerry A Toner Senior Licensing Engineer CC Administrator, Region III,.,,USNRC NRC Resident Inspector.. .

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