ML20004F896
| ML20004F896 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 06/23/1981 |
| From: | Colbert W DETROIT EDISON CO. |
| To: | Kintner L Office of Nuclear Reactor Regulation |
| References | |
| EF2-53859, NUDOCS 8106260141 | |
| Download: ML20004F896 (2) | |
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I-2000 Second Avenue Detroit. uchegan 48226 v-(313) 237-8000 June 23, F 01 5 2 - 53859
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U. S. Nuclear Regulatory Comnission
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Dear Mr. Kintner:
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Reference:
Enrico Fermi Atcznic Power Plant, Unit 2 NRC Docket No. 50-341
Subject:
Further Explanation for Exercising Plan for Pressure Isolation Valves Our letter on Inservice Inspection of Pressure Isolation Valves, EF2-52674, June 2,1981 states:
"These valves shall not be routinely exercised every three months
~ during plant operation as required by Ihv-3410 because:
1.
Such tests remove one of the two barriers protecting the low pressure portion (sf the emergency core cooling systems.
2.
":he operators on testable check valves cannot overcome the force on the valve with reactor pressure on one side."
The following is in response to a request frcxn Mr. Anthony Cappucci, NRC, to Detroit Edison to supply additional justification for this exercise program.
I A routine test every three months as described in IhV-3410 pre-supposes the test can be done with the plant operating at full power (and pressure). The purpose of dual barriers is to provide pressure isolation and protection even if one of the barriers should l
be faulty. Should one of the barriers be faulty by being inoperable, l
the core cooling systems have sufficient redundancy to perform their l
function. In addition, an inoperable barrier would be found during l'
the proposed tests made at cold shutdown.
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Mr. L. L. Kintner June 23, 1981 EF2 - 53859 Page 2 However, should one of the barriers be faulty by having excessive leakage, the core coolirg systs connected to that barrier could be i
severely damaged. Herefore, the test could cause a significant loss of primary coolant. On the other hand, had the test not been performed for this latter case, the core cooling system would have perfozmed its function normally We believe these arguments provide the sufficient justification for performing tests on pressure isolation valves only.during cold shut-down pa % and form the basis for our request for relief fr m the Code testing schedule.
Sincerely, Yb
- w. r. colbere Technical Director Enrico Fezmi 2.
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