ML19256E195
| ML19256E195 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 10/01/1979 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Jens W DETROIT EDISON CO. |
| References | |
| NUDOCS 7910300034 | |
| Download: ML19256E195 (3) | |
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UNITED STATES
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OCT 1 1979 Docket No. 50-341 Dr. Wayne H. Jens Assistant Vice President Engineering and Construction Detroit Edison Company 2000 Second Avenue Detroit, Michigan 48226
Dear Dr. Jens:
SUBJECT:
CONFIRMATORY REQUIREMENTS RELATING TO CONDENSATION OSCILLATION LOADS FOR THE MARK I CONTAINMENT LONG TERM PROGRAM On August 15, 1979, the staff met with representatives of the Mark I Owners Group to discuss the acceptance criteria being developed by the staff to begin implementation of toe Mark I Long Term Program (LTP).
One of the staff's criteria requires confirmatory condensation tests in the Full-Scale Test Facility (FSTF).
The Mark I Owners Group representatives stated that they consider additional FSTF tasts unnecessary.
As a result of our review of the proposed load definition procedures for the design basis accident " condensation oscillation" loads (i.e., high vent flow rate with low air content), we have concluded that there are insufficient data to establish a reasonable measure of the uncertainty to the load magnitudes for this regime. Although we believe that the condensation oscillation loads proposed in the Mark I Containment Program Load Definition Report (LDR), NED0-21888, are sufficiently conservative with respect to the results of FSTF test run M8, we have not found sufficient applicable data to give an adequate estimate of the uncertainty in the load magnitude so defined, such that we can assure that the uncertainty is smaller than the conservatism in the load definition technique.
In making this assessment, we have considered the use of the other full-scale data sources and small-scale phenomenological studies. The questions that have been raised regarding the applicability of these data to this issue have not been resolved and will not be resolved in the near future.
We believe that the LDR condensation oscillation load specifications, as modified by the staff's acceptance criteria, form a sufficient basis to proceed with implementation of the LTP, since FSTF test M8 is prototypical for Mark I and 77 358 7 9103 00 0 3Y A
Dr. Wayne H. Jens OCT 1 1979 the load definition technique has conservatively assessed that test data.
Consequently, we intend to issue the acceptance criteria to initiate the LTP plant-unique analyses. We will require in these criteria that the conservatism in the condensation oscillation loads be confirmed by performing a sufficient number of additional large break, liquid blowdown tests in FSTF to establish the uncertainty in the load magnitudes.
In addition, the staff has recently raised concerns relating to the phenomena associated with downcomer condensation oscillation loads.
These concerns evolved from insufficient downcomer-vent header response data. The additional FSTF test should provide improved instrumentation for the downcomer-vent header system, particularly for the " tied" downcomers.
We will require that each licensee commit, on behalf of the Mark I Owners Group as a whole, to perform these tests and provide the associated test and plan schedule by October 31, 1979.
SpIacerely,l (MN L M q teven A. Verga, Actb Assistant Director for Light ater Reactors Division of Project Management cc: See next page 9
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Eugene B. Thomas, Jr., Esq.
David E. Howell, Esq.
LeBoeuf, Lamb, Leiby & MacRae 21916 John R
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Hazel Park, Michigan 48030
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Washington, D. C.
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.7 Peter A. Marquardt, Esq.
. {"4 Co-Counsel Mrs. Martha Drake M.]
The Detroit Edison Company 230 Fairview
'i 2000 Second Avenue Petoskey, flichigan 49770 Tw Detroit, Michigan 48226
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k Mr. William J. Fahrner Project Manager - Fermi 2 The Detroit Edison Company
'M 2000 Second Avenue M
Detroit, Michigan 48226 f
40 fir. Larry E..Schuerman Licensing Enaineer - Fermi 2 Detroit Edison Company l
2000 Second Avenue j
Detroit, Michigan 48226 i
Charles Bechhoefer, Esq., Chairman m
Atomic Safety & Licensing Board M.-!
Panel U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Dr. David R. Schink Department of Oceanography Texas A & M University College Station, Texas 77840 1.4
,7 fir. Frederick J. Shon
'.M Atomic Safety & Licensing Board
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Panel V. S. Nuclear Regulatory Commission Washington, D. C.
20555 ffr. Jeffrey A. Alson 772 Green Street, Building 4 Ypsilanti, Michigan 48197
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