ML19322A261
| ML19322A261 | |
| Person / Time | |
|---|---|
| Site: | Crane, Crystal River  |
| Issue date: | 02/28/1979 |
| From: | Herbein J METROPOLITAN EDISON CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| GQL-0233, GQL-233, NUDOCS 7903070217 | |
| Download: ML19322A261 (2) | |
Text
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'} j ib id qq PennsyWr.i 19603 215 9a 501 February 28, 1979 GQL 0233 Director of Nuclear Reactor Regulation Attn:
R. W. Reid, Chief Operating Reactors Branch No. 4 U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Sir:
Three Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Decay lleat Pumps In response to your letter of January 29, 1979, the following information is submitted to verify that Decay Heat Pump impeller to casing rubbing is not of concern for the Decay lleat Pumps installed at TMI-1.
1.
The impeller-casing rubbing at Crystal River 3 (CR-3) was apparently the result of a tolerance interference caused during manufacture of the pump casing. The TMI-1 casings and the CR-3 casings were manu-factured at different times and cast by different foundries.
Th e re-fo re, it is highly unlikely that the casing defect is generic and present in the TMI-1 pump casings.
2.
A TMI-1 spare pump casing, which was manufactured about the same time and cast at the same foundry as the TL1-1 installed casings, was examined at TMI-1, and the results were discussed with Worthington.
Worthington confirmed that the measurements taken indicate acceptable tolerances, and that there is no reas,n to believe that the installed casings are of lesser quality.
3.
TMI-1 has never experienced any abnormal operation of the pumps that could indicate interference rubbing.
4.
1MI-1 replaced the pump shafts during the 1978 refueling outage and performed NDT on the replaced shafts.
There were no linear indications in the area where bending fatigue due to interference rubbing would occur.
5.
When the pumps were disassembled for shaft replacement during the 1978 refueling outage, the impellers were examined, and no indica-tions of rubbing were found.
Based on the above, in addition to the many hours of reliable operation (2493.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> on DH-P1 A and 3688.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> on DH-PIB), Met-Ed has concluded, and both Worthington and B6W concur, that the problem experienced at Crystal River is of 090 7903070 A/7
(
Metropottan Edson Company is a Member of the General Pubhc UMttes System
s.
'R. W. Re.id, Chief February 28, 1979 GQL 0233 no concern relative to the TMI-l Decay lleat Pumps.
Furthermore, Met -Ed is extremely confident that the TMI-l Decay IIcat Pumps will maintain their high degree of reliability and will be capable of performing their safety functions as described in the TMI-l FSAR. Continued assurance of the reliability of the
. TMI-1 pumps is obta ned during the monthly Inservice Inspection Testing i
4 performed in accordance with the requirements of ASME Section XI.
Sincerely, l
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J. G. Herbein i
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