ML20059L904
| ML20059L904 | |
| Person / Time | |
|---|---|
| Issue date: | 11/15/1993 |
| From: | Chilk S NRC OFFICE OF THE SECRETARY (SECY) |
| To: | Larkins J, Taylor J Advisory Committee on Reactor Safeguards, NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| References | |
| REF-10CFR9.7 M931029, NUDOCS 9311170487 | |
| Download: ML20059L904 (2) | |
Text
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UNITED STATES
/k NUCLEAR REGULATORY COMMISSION
{ c )- )"q,i W ASH INGTON, D.C. 20555
[f IN RESPONSE, PLEASE o,,,,e November 15, 1993 REFER TO:
M931029 OFFICE OF THE SEC R ET A R Y MEMORANDUM TO:
James M. Taylor Executive Director for Operations John T.
Larkins Executive Director for AC ACNW FROM:
Samuel J.
Chilk, Secretary 3
SUBJECT:
STAFF REQUIREMENTS - BRIQING ON STATUS OF THERMO-LAG, 10:00 A.M.,
FM DAY, OCTOBER 29, 1993, COMMISSIONERS' CONFERENCE ROOM, ONE WHITE FLINT NORTH, ROCKVILLE, MARYLAND (OPEN TO PUBLIC ATTENDANCE)
The Commission was briefed by the NRC staff on the status of the actions to resolve the Thermo-Lag fire barrier issues.
The staff has done a good job in oversight of the industry to assess and I
evaluate testing.
However, the Commission is concerned with whether the current program will lead to timely resolution of the l
fire barrier issue.
The Commission is concerned that even if technical agreement is reached between the staff and NUMARC and the testing can be completed, the test results may not necessarily assure a solution to the Thermo-Lag fire barrier issue.
The Commission requests that the NRC staff perform the following tasks:
1)
Have the ACRS review the technical differences that remain between NUMARC and the staff on the NUMARC test program.
The Commission would appreciate the ACRS's views on this issue.
2)
Inform the Commission of the proposed course of action for resolving the methodology and criteria differences especially with respect to the following issues:
(a) the degree of conservatism or margin provided by testing without cables in the trays as compared to testing with cables in the trays, (b) the difference in measured temperature with thermocouples located as proposed by NUMARC compared with staff's placement.
Illustrations of these situations would be useful, and 9311170487 931115 PDR 10CFR PT9.7 PDR 170007 6'U
... (c) information necessary to extrapolate data from a
simple, reference tests to actual as-built configurations.
3)
Encourage NUMARC to complete the testing and analyze the results.
The staff should promptly review the test results when available.
4)
Consider alternatives to the current program in the event the present course of action is not sufficient to reach an acceptable solution to this issue in a reasonable amount of time.
I 5)
Revise the staff's action plan to include points in the process where it would be prudent to consider implementing the alternatives and a reasonable deadline for resolving the Thermo-Lag issue.
For example, it may be possible to obtain a generic solution to the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> barrier and require site specific solutions to the 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> barrier; alternatively, it may be possible to identify other barriers and configurations.
On this issue, the Commission wants to know the number of plants that use only 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> barriers and how many use 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> barriers.
For those using 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> barriers, provide some measure of the extent of usage.
(EDO)
(SECY Suspense:
12/15/93)
The Commission is interested in a comparison of the fire protection requirements at foreign reactors with those in the U.S.
and the design (including materials) or operational measures being taken in foreign reactors with respect to this issue.
(EDO)
(SECY Suspense:
1/14/94) cc:
The Chairman Commissioner Rogers Commissioner Remick Commissioner de Plangue OGC OCA OIG Office Directors, Regions, ACRS, ACNW, ASLBP (via E-Mail)
PDR - Advance
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DCS - P1-24
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