ML20196J261

Application for Amend to License DPR-3,increasing Nitrogen Supply Pressure to Safety Injection Accumulator from 473 to 488 Pounds Per Square Inch Gauge.Fee Paid

ML20196J261
Person / Time
Site:	Yankee Rowe
Issue date:	06/27/1988
From:	Drawbridge B YANKEE ATOMIC ELECTRIC CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20196J266	List: ML20196J261 ML20196J283
References
FYR-88-88, NUDOCS 8807060349
Download: ML20196J261 (3)

Text

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,' TtI1 phon 0 (6ti) 872 8100 TWX 710-380-7619 YANKEE ATOMIC ELECTRIC COMPANY yANKa:i:: k 1671 Worcester Road, Framingham, Massachusetts 01701

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June 27, 1988 FYR 88-88 P.C. 221 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Reference:

(a) License No. DPR-3 (Docket No. 50-29)

Subject:

Request for Change to Technical Specification 3.5.1.e

Dear Sir:

Pursuant to Section 50.90 of the Commission's Rules and Regulations, the Yankee Atomic Electric Company (YAEC) hereby requests the authorizatica to make the following change.

Proposed Change Reference is made to the Technical Specifications of License No. DPR-3.

We propose to modify Technical Specification 3.5.1.e to increase the N2 supply pressure to the Safety Injection (SI) accumulator from the existing value of 473 10 psig to 488 125 psig.

Reason for Change This change is being made to reflect the observed pressure fluctuation in the safety injection accumulator nitrogen header supply pressure. These ambient temperature induced pressure fluctuations coupled with the regulating valve set point tolerance, have resulted in oa operating pressure range nearly equal to current Technical Specification value of 10 psi. This change will give the plant operators more latitude in maintaining the desired system pressure.

Basis for Change The proposed N2 supply pressure setpoint of 488 225 psig will alleviate unnecessary instrument and control recalibration requirements. By increasing the N2 aupply pressure setpoint to 488 psig and increasing the tolerance to 125 psig, a more meaningful and consistent indication of system status will be achieved without compromising system performance or equipment design specifications.

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United States Nuclear Regulatory Commission June 27,1988 Page 2 FYR 88-88 Safety Considerations The proposed new N2 supply pressure to the SI accumulator does not expose the plant to an increased chance of failure of either the SI System or the N2 Supply System. The impact of raising accumulator N2 Pressure on a Loss of Coolant Accident (LOCA) has been analyzed by Yankee. The results of this analysis indicate that the increased accumulator pressure results in a decrease of approximately 200F in Peak Clad Temperature (PCT). The increased pressure is well within the design of the system components. As such, this proposed change would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated. This change increases the operating pressure of the SI accumulator in order to adequately monitor the operational readiness of the Safety Injection Accumulator Nitrogen Supply 8ystem. The increased operating l pressure has a favorable impact on the Yankee LOCA analysis resulting in a decrease in the calculated peak clad temperature. It is also within the design capability of system components.

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{ 2. Create the possibility of a new or different kind of accident from any previously analyzed. This change provides for consistent pressure indication of the SI accumulator without changing system functional operability requirements or exceeding component design limitations. Therefore, it does not create the possibility of a new or different kind of accident.

3. Involve a significant reduction in a margin of safety. This change in accumulator setpoint will increase the margin of safety by reducing the PCT in a LOCA event. Normal operation of the system with an increased accumulator set pressure will also not involve a significant reduction in a margin of safety.

Based on the consideration contained herein, it is concluded that there is reasonable assurance that operation of the Yankee plant, consistent with the proposed Technical Specifications, will not endanger the health and safety of the public. This proposed change has been reviewed by the Nuclear Safety Audit and Review Committee.

f.ee An application fee of $150.00 is enclosed in accordance with 10CFR170.21.

United States Nuclear Regulatory Commission June 27, 1988 Page 3 FYR 88-88 Schedule of Change This change to the Yankee Technical Specifications will be implemented upon Commission approval. A timely review and approval of this submittal would be appreciated.

We trust that you will find this submittal satisfactory; however, should you desire additional information, please contact us.

Very truly'youri r /

YANKEE ATOMIC ELECTRICf R1EANY f ' n af?N b B. L. Drawbridgb Vice President / Manager of Operations BLD/05.250 COMMONWEALTH OF MASSACHUSETTS)

)ss MIDDLESEX COUNTY )

Then personally appeared before me, B. L. Drawbridge, who, being duly t, worn, did state that he is Vice President and Manager of Operations of Yankee Atomic Electric Company, that he is duly authorized to execute and file the foregoing document in the name and on the behalf of Yankee Atomic Electric Company and that the statements therein are true to the best of his knowledge and belief.

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Robert H. Groce Notary Public My Commission Expires August 29, 1991