ML20148J019

Discusses Util 690825 Proposed Change 89 to Tech Specs, Permitting Revisions in Core 8 Loading,Previously Authorized by Change 86.Authorizes Replacement of Region B Four Zircaloy Clad Rod Containing Test Assemblies

ML20148J019
Person / Time
Site:	Yankee Rowe
Issue date:	09/15/1969
From:	Morris P US ATOMIC ENERGY COMMISSION (AEC)
To:	Minnick L YANKEE ATOMIC ELECTRIC CO.
References
NUDOCS 8011200318
Download: ML20148J019 (2)

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H K Shapar, N SEP 151969 N Dube, DRL (5)

J R Buchanan, ORNL H J McAlduff, OR00 Docket No. 50-29 T W Laughlin, DTIE Document Room l

Aocket File l DR Reading I DRL Reading l Branch Reading Yankee Atomic Electric Company A. Burger 441 Stuart Street D Thompson Boston, Massachusetts 02116 ACRS (3)

Attention: L. E. Minnick Change No. 89 Vice President License No. DPR-3 1

Centlemen:

This refers to your request dated August. 25, 1969, for AEC authorisation of Proposed Change No. 89 to the Technical Specifications to Facility License No. DPR-3 for the Yankee reactor. The proposed change would pennit certain revisions in the loadtng of Core VIII (previously authorised by Change No. 86) .

Four test fuel assemblies have been irradiated in Core VII and were to be recycled in Core VIII as part of Yankee's program to confirm the adequacy of design and predicted performance of two types of mLrcaloy clad assemblies.

During the present refueling outage for loading of Core VIII, inspection of removable sircatay clad rods from the test fuel assemblies has estab.

lished that changes in the lengths of the fuel rods were greater than anticipated. Until Yankee investigates and resolves the unexpected physical changes in the strcaloy cladding, it will not recycle these test fuel assemblies: t :henes,;theyavi,11-nettbe loaded in Core VIII as plar.ned.

Yankee proposes to change Core VIII by replacing the four test assemblies in Region 3 containing strealoy clad rods with a like number of standard fuel assemblies, originally 4.947. enriched uranium, stainless steel clad, which were irradfated in Cores VI and VII to an average burnup of 20,000 MWD /MTU. The four stainless steel clad fuel assemblies in Region A will have an average burnup of 20,700 MWD /MTU compared to the average burnup of 20,000 MWD /MTU previously pl&nned for Core VIII. In all other respects, loading sad operation with Core VIII will remain as described in Change No. 86.

1 Although the proposed change will cause a slight redistribution of power, I Yankee has determined, and we agree, that it has essentially no effect #

l on thi calculated hot channel factors used in the initial analysis and that itlwill not signf tteantly cna ge tne opera!: tag conatti s or vore vut.

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2-Shutdown margins and reactivity control parameters remain essentially unchanged from those evaluated for the initial Core VIII loading. However, Yankee's reevaluation of the thermal capabilities shows that the proposed change to Core VIII would result in a slightly lower maxirntsu her.t flux and in a slightly higher minimum DNB ratio with corresponding increases in the respective margins of safety.

Based on our evaluation of the revised loading, we have concluded that previously established margins of safety will not be adversely affected, and that they are adequate for the safe operation of the Yankee reactor i with the proposed changes in the loading of Core VIII. l We have also concluded that the proposed change does not present sigtnifi- l l

cant hazards considerations not described or implicit in the hazards l summary report, and that there is reasonable assurance that the health and safety of the public will not be endangered by operation of the Yankee reactor with the revised Core VIII in the manner proposed.

Accordingly, pursuant to Section 50.59, 10 CFR Part 50, Proposed Change

' No . 89 is hereby authorized.

Sincerely, Peter A. Morris, Director Division of Reactor Licensing omct > ..D,RL; ORB ,,lp DRL; ORB,,,1,_, ,DRL0)B,[,

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