ML19254C583

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Discusses Need for Addl Confirmatory Full Scale Tests to Establish Uncertainty in Load Magnitudes Re Condensation Oscillation Load Definition Procedures.Draft Ltr to Mark I Utils Re Test Program Encl
ML19254C583
Person / Time
Site: Millstone, Hatch, Monticello, Dresden, Peach Bottom, Browns Ferry, Nine Mile Point, Fermi, Oyster Creek, Hope Creek, Cooper, Pilgrim, Brunswick, Vermont Yankee, Duane Arnold, Quad Cities, FitzPatrick
Issue date: 09/25/1979
From: Grimes B
Office of Nuclear Reactor Regulation
To: Gammill W, Varga S, Vollmer R
Office of Nuclear Reactor Regulation
References
REF-GTECI-A-07, REF-GTECI-AC, REF-GTECI-CO, TASK-06-02.A, TASK-A-07, TASK-A-7, TASK-OR, TASK-RR NUDOCS 7910170010
Download: ML19254C583 (4)


Text

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[ga arcg'o, UNITED STATES l'

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'v SEP 2 51979 Generic Task A-7 MEMORANDUM FOR:

W. Gammill, Acting Assistant Director for Operating Reactor Projects D0R R. Vollmer, Acting Assistant Director for Systematic Evaluation Program, D0R S. Varga, Acting Assistant Director for Light Water Reactors OPM THRU:

D. G. Eisenhut, Acting Director Division of Operating Reactors FROM:

B. K. Grimes, Acting Assistant Director for Systems Engineering, D0R

SUBJECT:

REQUIREMENTS FOR CONFIRMATORY TESTING FOR THE MARK I CONTAINMENT LONG TERM PROGRAM As a result of the staff's review of the " condensation oscillation" load definition procedures, proposed for use in the Mark I Long Term Program, we have concluded that additional, confirmatory full-scale tests will be necessary to establish the uncertainty in the load magnitudes. Consequently, we have prepared the enclosed sample letter which requires that each Mark I licensee or applicant comit, on behalf of the Owners Group, to perform such a testing program.

The enclosed sample latter should be transmitted to each Mark I licensee or applicant within seven (7) days of the date of this memorandum. Should you have ar.y questions concerning this action, contact C. Grimes (X28204).

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. K. Grimes, Acting Assistant Director for Systems Engineering Division of Operating Reactors

Contact:

C. Grimes, X28204

Enclosure:

As stated

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cc: See next page 0

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7910170

SEP 2 51979 Multiple Addressees -

cc:

D. Eisenhut S. Hanauer M. Aycock B. Grimes L. Shao G. Lainas E. Ade, sam V. Noonan R. Tedesco W. Butler J. Kudrick C. Anderson T. M. Su K. Wichman J. Fair C. Grimes D. Ziemann T. Ippolito l'.

Denton T. Carter C. Hofmayer

  • J. Stolz R. Baer R. Hartfield D. Thompson 1153 534

Enclosure UTILITY Gentlemen

SUBJECT:

CONFIRMATORY REQUIREMENTS RELATING TO CONDENSATION OSCILLATION LOADS FOR THE MARK I CONTAINMENT LONG TERM PROGRAM On August 15, 1979, the staff met wit 5 representatives of the Mark I Owners Group to discuss the acceptance criteria being developed by the staff to begin implementation of the Mark I Long Tem Program (LTP). One of the staff's criteria requires confimatory condensation tests in the Full-Scale Test Facility (FSTS). The Mark I Owners Group representatives stated that they consider additional FSTF tests 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 in 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 phenomenlolgical 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 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 instrurentation for the downcomer-vent header system, particularly for the " tied" downcomers.

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a Multiple Addresses 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.

Sincerely, t-if

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'17. G. 'Eis'enhut' Act'ing Di rector Division of Operating Reactors 1iSa 336 e

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