ML20076D712

Application for Amend to License R-123,changing Tech Specs to Remove Item 3.2.b Re Subcriticality W/Single Rod Inserted & to Modify Section 5.1 Re Fuel Elements

ML20076D712
Person / Time
Site:	University of Virginia
Issue date:	05/10/1983
From:	Brenizer J VIRGINIA, UNIV. OF, CHARLOTTESVILLE, VA
To:	Thomas C Office of Nuclear Reactor Regulation
References
NUDOCS 8305230548
Download: ML20076D712 (2)

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UN' /ERSITY OF VIRGINIA School oF ENGINEERING AND APPLIED SCIENCE CH ARLOTT ESVILLE, 22901 DEPARTMENT OF N UCLEAR ENGIN EERING AND ENGIN EERING PHYSICS TELEPHON E: 804-924 7836 REACTOR FACILITY May 10, 1983 Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555 Attn: Mr. Cecil O. Thomas, Chief Standardization and Special Projects Branch RE: Docket No. 50-396 License No. R-123

Dear Mr. Thomas:

An amendment is hereby requested for Facility License R-123, Docket number 50-396 to revise the Technical Specifications for the CAVALIER Reactor.

We request the following changes.

A. Under Section 3.0 (Limiting Conditions for Operation) we recuest the removal of iten 3.2.B. which states that the reactor shall be sub-critical with any single rod inserted and the other three rods fully withdrawn.

Bases: The CAVALIER Tech Specs. 1.5 and 3.2.A requires a shutdown margin of >0.4% Ak/k with the highest worth rod fully withdrawn and 3.2.G requires a limit of 1.6% Ak/k in excess reactivity. We feel these two limitations provide adequate safety for the reactor. The additional limit of being sub-critical with any three rods withdrawn (3.2.B) places an unusually strict limit on the operation of the reactor, especially in the capability of calibrating control rods adequately to determine their overall worth and to have the flexibility of operating with different core configurations. With the present restriction we are able to have only ~0.6% Ak/k excess reactivity in order to be sub-critical with three rods withdrawn and are limited to only one core configuration.

B. Under Section 5.1 (Reactor Fuel) we request a change in the specification of the fuel elements as follows:

Specification:

The fuel elements shall be of the materials testing reactor (MTR) type consisting of plates containing highly enriched uranium i

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k Office of Nuclear Reactor Regulation Page 2 May 5, 1983 alloy fuelf clad with aluminum. There shall be 12 fuel plates containing 165 (+ 3%) grams of U-235 or 18 fuel plates containing 195 (+ 3%) grams of U-235, in the standard fuel elements. There shall be six fuel plates containing 82.5 (+ 3%) grams of U-235, or nine fuel plates containing 98 (+ 3%) grams of U-235, in the control rod fuel elements. Partially loaded fuel elements in which some of the fuel plates do not contain uranium may be used.

The mass of U-235 listed above refers to the initial (zero burnup) loading.

Various core configurations may be used to accommodate experiments, but the loadings shall always be such that the minimum shutdown margin and excess reactivity as specified in Section 3.2 of these specifications are not exceeded.

Bases: The present specifications on fuel elements allows only the twelve plate fuel elements to be used in the CAVALIER. These particular fuel elements are no longer being manufactured. The eighteen plate fuel elements have been run in the UVAh reactor at 2MW for 8 years and would create no safety problems for the CAVALIER.

These changes have been reviewed and approvod by the '

Reactor Safety Committee.

We request that these changes be given prcmpt consideration since we would like to make these changes within the next two months.

Sincerely, W%

J.S. Brenizer, Director UVA Reactor Facility JSB:vs cc: J.P. Farrar T.G. Williamson Reactor Safety Committee 7"& W

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