ML20204E678
| ML20204E678 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 07/30/1986 |
| From: | Agosti F DETROIT EDISON CO. |
| To: | Adensam E Office of Nuclear Reactor Regulation |
| References | |
| TAC-63529, VP-86-0108, VP-86-108, NUDOCS 8608010204 | |
| Download: ML20204E678 (3) | |
Text
"
l Nc*e"P dsWt Nuclear Operations Md Detroit r.
a lc A n D NcNa7"E87'l July 30, 1986 Nuclear ovl I (313i s*415 VP-86-0108 OP8" "
Director of Nuclear Reactor Regulation Ms. Elinor G. Adensam, Director Project Directorate No. 3 Division for BWR Licensing U. S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Ms. Adensam:
References:
(1)
Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43 (2)
Inservice Testing Program for Pumps and Valves, NE-5.6-IST (3)
Fermi 2 SER, Supplement 1, page 6-3 (4)
Letter, W.F. Colbert to L.L. Kintner July 31, 1981, EF2-54195 (5)
ASME Section XI, 1980 Edition, Winter 1980 Addenda, paragraph IWV-3427 (6)
Fermi 2 SER, Supplement 4, page 3-1
Subject:
Modification of Acceptance Criteria for Surveillance Leakage Tests on Drywell Purge and Vent Valve's with Resilient Seals Detroit Edison is currently required, by the Fermi 2 Technical Specifications (Ref. 4. 6.1. 8. 2), to verify, by leak testing, the operability of each 6, 10, 20 and 24 inch drywell and suppression chamber purge supply and exhaust isolation valve.
Per the Fermi 2 Technical Specifications the acceptance criteria for these tests require that the total leakage be less than or equal to 0.05La, when_ pressurized to Pa.
In response to NRC concerns over containment isolation valves with resilient seals, Detroit Edison committed, via letter EF2-54195, to a more stringent acceptance criteria.
This commitment requires that the subject valves be repaired if test results indicate the leakage has increased by 20% from the previous test.
This commitment was acknowledged in Fermi 2 SER, Supplement 1.
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P p
o Ms. Elinor G. Adensam July 30, 1986 VP-86-0108 Page 2 During performance of Surveillance 43.401.510, test results exceeded the 20% increase criteria as presented in EF2-54195.
Upon review of the acceptance criteria it became evident that the acceptance criteria was too restrictive in that it did not consider the effect of extremely good previous Type "C" test results.
For Example:
Penetration Type-C Leakage Previous Current Operability X-25 Limit Type C Results Surveillance Results T4803-F602 9.34 SCFH 0.644 SCFH 1.04 SCPH T46-F402 T46-F411 The operability Surveillance result of 1.04 SCPH is over 20%
greater than the previous Type "C" test result of 0.644 SCFH and therefore requires the valves to be repaired.
This is neither practical nor desirable since repair of the valve, most likely, will not improve it's leakage.
Valves containing resilient seals are in their original condition and no seal replacement has been performed \\to date.
Fermi 2 recently performed type C tests, as required by the IST program.
The test results show no sign of seal degradation.
The Fermi 2 preventative maintenance program requires seal replacement during the second refueling outage.
The Fermi 2 Inservice Testing Program for pumps and valves commits to the testing requirements of pumps and valves in accordance with Section XI of the ASME Boiler'and Pressure Vessel code, 1980 Edition, through the Winter 1980. Addenda,
.with certain exceptions.
Thi.s commitment w'as found acceptable in SSER 4, section 3.9.6, paragraph 2.
The intent of'the Operability Surveillance can be met by substituting the acceptance criteria of ASME Section XI, 1980 Edition, Winter 1980 Addenda, paragraph INV-3427(b).
This pa,ragraph requires that if the measured leakage rate exceeds the previous test result and reduces the margin between the measured leakage rate and the maximum permissible by 50% or greater, the test frequency shall be doubled.
If tests show a leakage rate increasing with time, and a projection based on three or more tests indicates that the leakage rate of the next scheduled test will exceed the maximum leakage rate by greater than 10%,
the valve sha]l be repaired or replaced.
.'\\
Ms. Elinor G. Adensam July 30, 1986 VP-86-0108 Page 3 Based on the above discussion, Detroit Edison requests modification to section AT-8 (and its associated acceptance criteria) of the Inservice Testing Program for pumps and valves via replacing the current 120% of the previous type-C test result criteria with that of ASME section XI, 1980 Edition, winter 1980 Addenda, paragraph IWV-3427(b).
With this change, Detroit Edison continues to comply fully with the requirements of 10CFR50 Appendix J and the Fermi 2 Technical Specification requirements.
If you have any question in this matter please contact Mr.
Frank Sondgeroth at (313) 586-5243.
Sincerely, p#l b
~~~
cc:
M. D. Lynch W. G. Rogers G. C. Wright USNRC Document Control Desk Washington, D. C.
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