ML19351D762

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Hazards Analysis Supporting Proposed Change 62 to Tech Specs,Authorizing Mod of Flow Rate Specs of Pressure Reducing Orifices
ML19351D762
Person / Time
Site: Yankee Rowe
Issue date: 04/30/1965
From: Boyd R
US ATOMIC ENERGY COMMISSION (AEC)
To:
Shared Package
ML19351D761 List:
References
NUDOCS 8011180268
Download: ML19351D762 (1)


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SAFETY EVALUATION BY THE RESEARCH AND POWER REACTOR SAFETY BRANCH DIVISION OF REACTOR LICENSING IN THE MATTER OF YANKEE AT WIC ELECTRIC COMPANY PROPOSED CHANGE NO. 62 DOCKET NO. 50-29 Introduction Pursuant to the provisions of Section 50.59 of the Commission's regulations, Yankee Atomic Electric Company, in Proposed Change No. 62, requested a change in the Technical Specifications of License No. DPR-3.

The proposed change would authorize modification of the f'.ow rate specification of the pressure reducing orifices located in the bleed line of the primary coolant system.

Discussion 5

During normal operation of the Yankee reactor, bleed flow rate is controlled by three parallel connected pressure naducing orifices rated at 25 gpm, 25 gpm, P

c b""g and 75 gpm. Pressurizer water level is maintained by automatically operated qg variable speed charging pumps which provide feed water to the primary coolant system at a rate needed to balance the bleed flow rate. When a low water G

1evel condition exists in the pressurizer vessel, all bleed flow is stopped by closure of a diaphragm-operated valve in the bleed line downstream cf the

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orifices.

Wearing of the two 25 gpm orifices has proceeded to the point where'it is now necessary to operate two charging pumps to balance the bleed flow through a 25 gpm orifice. To increase effective service life, the licensee proposes to replace the two low flow orifices with orifices having a nominal rating of 20 gpm. Also, to provide flexibility in meeting future conditions, the licensee wants to be able to change the low flow orifices in the range from 15 to 35 gpm, and the high flow orifice in the range from 50 to 75 gpm. We believe that the safety of reactor operations will not be adversely affected by this change.

Conclusion We have concluded that the proposed change does not present significant hnzards conditions not described 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.

Criginal d;r.d y Ecgr S. Boyd Roger S. Boyd, Chief Research & Power ' Reactor Safety Branch Division of Reactor Licensing g

t Date:

AU. 3 0 E55 "8011180 M b

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