ML19259B949

RO 78-01 on 780105:inlet Piping to Safety Relief Valves Was 6-inch Double Extra Strong,Causing Inside Diameter to Be Slightly Smaller than Throat Diameter of Valve.Vendor Evaluation Rept Due in Feb

ML19259B949
Person / Time
Site:	FitzPatrick
Issue date:	01/05/1978
From:	Pasternak R POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 7906040225
Download: ML19259B949 (1)

Text

, TELECOPY MESSAGE TV: Mr. Soyce H. Grier From: Mr. Raymond .s. Pas ternak Director of Regulatory Operation Superint endent of Power USNRC Region I Power Authority of the State of N. Y.

631 Park Avenue J. A. Fit: Patrick Nuclear P&wer Plant King of Prussia, PA 19406 P. O. Box 41 Lycoming, New York 13093 SUBJ2CT: PROWT REPORTABLE OCCURRENJ (Potential)

Docket No. 50-333 License No. DPR-59 COhTIRMS TELEPHONE NOTIFICATION TO Hr. T. T. V.irtin on January 5, 1978 REPORT DATE: January 5, 1978 EVENT DESCRIPTION:

During a review of the Nuclear Boiler Safety Relief Valve piping, it was discovered that the inlet piping to the safety relief valves was 6" double extra strong. The inside diameter of the installed piping is thus slightly smaller than the throat diameter of the valve. This might affect the ability of the relief valves to limit the peak over-pressure to that calculated in NEDO-21619, BWR Reload I - License Amendment for the James A. Fit: Patrick Nuclear Power Plant, Full Core Drilled Conditions.

COMPONENTS INVOLVED:

Nuclear Boiler System Safety Relid Valves and associated inlet piping.

CAUSE AND REMEDIAL ACTION:

The Power Authority in concert with its Nuclear Steam Supply Vendor and Architect Engineer, has conducted a preliminary evaluation of the effects of using pipe with a smaller inside dimeter. Our estimate is that the limiting peak overpressure will be increased by a minum of approximately S-6 psi. We do not consider this to have significant impact since the James A. Fit: Patrick Nuclear Power Plant is very conservatively designed with respect to overpressure transients. The liniting transient is a MSIV closure at full power with flux scram.

NEDO-21619 calculates a peak overpressure of 1243 psi. We estimate that will be increased to 1248-1249 psi. The safety limit is well above.this.

The Nuclear Steam Supply Vendor has been requested to perform a de-tailed evaluation of the effect of the decreased inlet pipe diameter on relief valve capability and they have been requested to redo those portions of the Reload I Safety Analysis which are affected by relief valve capability. The results of this evaluation are due in February.

We will provide you the information when available.

.CACILITY STATUS:

Power Operation _ f TC: M1 nager / Nuclear Operations B(Aaymond J. Pasternak v Chairr.an - Safety Rev (750s:aigtee Superintendet of Power )h ed '

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