ML17261B013

Proposed Tech Specs,Allowing Use of Reconstituted Fuel Assemblies

ML17261B013
Person / Time
Site:	Ginna
Issue date:	03/15/1990
From:	ROCHESTER GAS & ELECTRIC CORP.
To:
Shared Package
ML17261B011	List: ML17261B010 ML17261B012 ML17261B013
References
NUDOCS 9003270048
Download: ML17261B013 (6)

Text

ATTACHMENT A Revise the Technical Specification pages as follows:

Remove Insert 5.3-1 5.3-1 9003270 048 90031>

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5.3 Reactor Desi Features 5.3.1 Reactor Core

a. The reactor core contains approximately 45 metric tons of uranium in the form of uranium dioxide pellets. The pellets are encapsul'ated in Zircaloy 4 tubing to form fuel rods. The reactor core is made up of 121 fuel assemblies"'ith each fuel assembly containing 179 fuel rod locations. Fuel rod locations at any time during plant life, may consist of fuel rods clad with Zircaloy -4 or filler rods fabricated from Zircaloy 4 or stainless steel if justified by cycle-specific reload analysis. Should more than 30, rods in the core, or 10 rods in any assembly be replaced per refueling, a report describing the number of rods replaced and associated cycle-specific evaluation shall be submitted to the Commission prior to criticality.

Each fuel assembly also contains 16 guide tubes and one instrumentation thimble all arranged in a 14 x 14 array to form a fuel assembly.

b. The enrichment of reload fuel shall be no more than 3.5 weight per cent U-235 for regions delivered prior to January 1, 1984 (Regions 1-15), 4.25 weight per cent U-235 for regions delivered after January 1, 1984, or their equivalents in terms of reactivity.

c. There are 29 full-length assemblies in the reactor core. Each RCC assembly contains 16 144 inch lengths of silver-indium-cadmium alloy clad with stainless steel which act as neutron absorbers when inserted into the core."'asis The DNBRs for the reconstituted assemblies are conservatively determined by assuming the filler rods are operating at the highest power in the reconstituted fuel assembly.

5.3-1 Proposed

Rochester Gas and Electric (RG&E) desires the flexibility to reconstitute fuel assemblies in order to reduce coolant activity and utilize the remaining energy in fuel assemblies which contain small numbers of defective fuel rods. In the reconstitution process, the fuel rods which are known to be defective will be removed and replaced with dummy rods (Zircaloy or stainless steel).

This reconstitution will be accomplished by either removing the top nozzle or by removing the bottom nozzle after inverting the assembly, inspecting and removing the defective rods, replacing the failed rods with dummy rods and reattaching the nozzle. If a fuel assembly skeleton is damaged, serviceable fuel rods and dummy rods may be transferred to a new skeleton. Fuel and dummy rod insertion and nozzle removal/reattachment remain the same as in the reconstitution process previously discussed. The reconstituted assembly will meet the original assembly design criteria.

The R.E. Ginna Nuclear Power Plant"Technical Specification 5.3.1.a describes the reactor core as consisting of assemblies containing 179 fuel rods. In order to allow for the insertion of reconstituted assemblies with dummy rods, this statement must be modified as proposed in Attachment A.

The use of reconstituted fuel assemblies in a reload core is considered acceptable because each reload that contains reconstituted assemblies will be evaluated using standard methods as described in Reference 1. The reload analysis will evaluate the effect of the actual reconstitution on core performance parameters, peaking factors, core average linear heat rate effects, and for the effect of the reconstitution on the LOCA-related analyses to ensure the existing safety criteria and design limits are met. In addition, reconstituted assemblies will meet the original assembly design criteria. The report requirement of 30 and 10 is arbitrarily chosen as a value above which the cycle-specific evaluation will be submitted to the Staff.

In accordance with 10CFR50.91, these changes to the Technical Specifications have been evaluated to determine if the operation of the facility in accordance with the proposed, Amendment would:

1. involve a significant increase in the probability or consequences of an accident previously evaluated; or

2. create the possibility of a new or different kind of accident from any accident previously evaluated; or

3. involve a significant reduction in the margin of safety.

The reconstituted fuel assemblies meet the same design requirements and satisfy the same design criteria as the original fuel assemblies. Cycle specific reload evaluations will apply existing safety criteria and design limits. Therefore use of reconstituted fuel assemblies does not involve a significant increase in. the probability or consequences of an accident previously evaluated..

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The reconstituted fuel assemblies satisfy the original design criteria and the reload in which the fuel assemblies are used is

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evaluated to ensure existing safety criteria and design limits are met. Therefore, the possibility of a new or different kind of accident is not created by the use of reconstituted fuel.

The required cycle specific reload analysis will ensure existing safety criteria and'esign limits are met. This will ensure there is no reduction in a margin of safety.

Based on the above discussions, Rochester Gas and Electric submits that the issues associated with this Amendment request are outside the criteria of 10CPR50.91 and a no significant hazards finding is warranted.

Reference 1. WCAP-9273A "Westinghouse Reload Safety Evaluation Methodology", July 1985 B-2

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TABLE 1 DETAILED TECHNICAL SPECIFICATION CHANGES Location Descri tion of Chan e Reason for Chan e Page 5.3-1 "...may consist of fuel rods Allow use of clad with Zircaloy -4 or reconstituted filler rods-4 or fabricated from stainless steel fuel.

Zircaloy if justified by cycle-specific reload analysis. Should more than 30 rods in the core, or 10 rods in any assembly be replaced per refueling, a report describing the number of rods replaced and associated cycle-specific evaluation shall be submitted to the Commission prior to criticality."

Replaced "are" with "all" is fuel assemblies.""'ording Deleted "The reactor core made up of 121 fuel Used in the insertion.

above Added, Basis: Requested by "The DNBRs for the reconstituted NRC Reviewer assemblies are conservatively determined by assuming the filler rods are operating at the highest power in the reconstituted fuel assembly."

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