ML20148J509

Approves Proposed Change 85 to Tech Specs,Authorizing Operation of Reactor W/Core 7 W/Reduction from 18 to 7 in Number of Locations at Which Flux Wires Can Be Inserted in Core

ML20148J509
Person / Time
Site:	Yankee Rowe
Issue date:	05/12/1969
From:	Morris P US ATOMIC ENERGY COMMISSION (AEC)
To:	Coe R YANKEE ATOMIC ELECTRIC CO.
References
NUDOCS 8011240218
Download: ML20148J509 (2)

Text

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W. Dooly R. Engelken i

H. Shapar MAY 22 g l

N. Dube J. R. Buchanan Docket No. 50-29 H. J. McAlduff W. B. Kenna Docket File AEC Doc. Room DR Reading DRL Reading Yankee Atomic Electric Company ORB-1 Reading 441 Stuart Street Boston, Massachusetts 02116 Attention: Mr. L. E. Minnick Change No. 85 Vice President License No. DPR-3 Geatienen:

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Your letter dated April 18, 1969, designated as Proposed Change No. 85, i

requested a change in the Technical Specifications for Licanas No. DPR-3 to authorise the operation of the reactor with Core VII with a reduction from 18 to 7 in the number of locations at which flux wires can be inserted in the core. This proposed change would supersede the provisions of Section 107 of the Final Hazards Summary Report, Core Instrumentation and particularly Instrumentation Location Diagram on page 107.3.

The power distribution in the Yankee core is monitored by core outlet thermocouples and the flus wire system. This information is used to deter-eine the core power distribution. Data obtained during operation with previous cores have verified that the analytical predictions of core power distribution are conservative estimates of the actual operating conditions.

Because of the symmetrical fuel loading and control rod pattern, large safety margins exist in the Yankee core (DNBR)3). We understand that you are in the coastdown stage of your fuel cycle with Core VII, operating at-520 Mwt instead of the authorised 600 Mwt, which adds to the safety margins in the hot channel factors.

In addition, since the reactor power level is controlled primarily by chemical shin and not by control rod motion, the probability of inducing large changes in the reactor power distribution is small. Therefore, we conclude that reactor operation with the seven avail-able flux wires and 27 core thermocouples supplemented by analytical pre-dictions is satisfactory for the remainder of the life of Core VII.

We have reviewed Proposed Change No. 85 pursuant to Section 50.59 of the Commission's regulations and have concluded that the proposed change to Section 107 does not presont significant hasards considerations not described THIS T CONTMm onn, -

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NAY 121969 Yankee Atomic Electric Company or implicit in the Hazards Summary Report and that there is reasonable assurance that the health and safety of the public will not be endangered by operation in this manner.

sincerely, Peter A. Morris, Director Division of Rasetor Licensing

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