ML20236W256
| ML20236W256 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 11/30/1987 |
| From: | Edelman M CLEVELAND ELECTRIC ILLUMINATING CO. |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| PY-CEI-OIE-0294, PY-CEI-OIE-294, NUDOCS 8712070358 | |
| Download: ML20236W256 (3) | |
Text
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1 THE CLEVELAND ELECTRIC iLLUMIN ATlWG C0iaPANY l
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BOX 97 a PERRY, OHIO 44081 a TELEPHONE (216) 259-3737 a
ADDRE SS - 10 CENTER ROAD Semng The Best Location in the Nation Murray R. Edelman PERRY NUCLEAR POWER PLANT
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flLE g Mr. A. Bert Davis Regional Administrator, Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road 1
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Perry Nuclear Power Plant Docket No. 50-440 Additional Information to Letter PY-CEI/01E-0289 L
Dear Mr. Davis:
This letter provides the evaluation committed to in our letter PY-CEI/01E-0289 L, dated November 13, 1987. As stated in the attached report, the evaluation determined that there were no adverse affects on long term qualified life for Class lE equipment due to the presence of known steam leaks.
If you have any questions, please feel free to call.
Very truly yours, Murray R. Edelman Senior Vice President Nuclear Group MRE: cab Attachment cc:
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Attechmtnt PY-CEI/0IE-0294 L Page 1 of 2 Evaluation Of Class IE Equipment Qualified Life In response to concerns generated by the Main Steam Isolation Valve (MSIV) dual solenoid failures, an equipment qualification reviev was initiated to consider possible adverse effects of local area temperature increases resulting from known steam leaks. These temperature increases were believed to have contributed to the MSIV dual solenoid valve failures.
In order to ensure that no other Class lE equipment was affected by those elevated temperatures, various steps were initiated. As previously discussed in our letter PY-CEI/0IE-0289 L dated November 13, 1987, inspections of Limitorque actuators were performed and found no steam or heat degradation.
"o supplement the visual inspections an evaluation for possible long term tiverse af fects on Class 1B equipment was performed. The evaluation focused on two major considerations; increased general area temperatures and higher localized area temperature. Two known steam leaks were included in the evaluation, one from the IN27F0559B Feedvater System check valve (located inside the dryvell) and the other from lE32F0001N HSIV Leakage Control System valve (located in the steam tunnel).
Several other minor leaks were known to have existed at the time but were evaluated as having an insignificant effect on area and local temperatures.
Class 1E equipment in the affected areas of the dryvell and the steam tunnel include Limitorque motor actuators, Pyco temperature elements and Namco limit switches. All three of these types of equipment are qualified to at least 140 degrees. Consequently, no reduction in qualified service life was realized due to area temperature increases.
Evaluation of the steam leaks in both the dryvell and the steam tunnel also determined that high local area temperatures (> 212 degrees F) could have existed, but would be limited to a small radius surrounding the respective leak.
However, none of the Pyco temperatures elements or the Namco limit switches were in a proximity to either leak such that their local area temperatures vould be significantly affected. Consequently, the general area evaluation discussed above is sufficient to ensure that no change occurred in their qualified service life.
The steam leaks were evaluated to determine an approximate temperature gradient at various distances from the leak.
Some of the Limitorque motor actuators are located sufficiently close to the respective steam leaks that their local temperatures were analyzed to possibly be higher (approximately 212 degrees F) than that of the general area. No other Class 1E components were identified to be within this distance or close enough to experience any significant temperature increase. However, Limitorque motor actuators in the vicinity of the feedvater leak were conservatively re-evaluated for qualified life including 277 days (total operating time of PNPP above 200 degrees) with a continuous conservative exposure to ar expected elevated temperature of 212 degrees F. Based on Arrhenius methodology and the conservative estimate of leak duration, the actuators remained qualified for greater than 40 years.
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Attachmant PY-CEI/01E-0294 L Page 2 of 2 The leak in the steam tunnel was also evaluated. No Class 1E equipment was determined to be within the range of the observed steam plume. At the edge of this plume, the maximum expected temperature is 212 degrees'F. As in the case of the feedvater valve leak, Limitorque motor actuators were evaluated conservatively, assuming 277 days of continuous exposure at this temperature.
Again, there was no effect on the actuator's qualified life. No other Class 1E equipment was within this affected area.
All of these conclusions are consistent with the visual inspections which were conducted. These inspections found no evidence of degradation in any of the Class 1E equipment which could have been affected by the aforementioned steam leaks.