ML20059E278

Safety Evaluation Granting Licensee 900525 Relief Requests RP-14 & RP-15 from Requirements to Measure Pump Inlet Pressure & Instrument Ranges,Respectively

ML20059E278
Person / Time
Site:	Cooper
Issue date:	08/31/1990
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20059E270	List: ML20059E269 ML20059E278
References
NUDOCS 9009100117
Download: ML20059E278 (2)

Text

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/c.uu\,, UNITED STATES  !

NUCLEAR REGULATORY COMMISSION

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ENCLOSURE SAFETY EVALVATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION PUMP AND VALVE TESTING PROGRAM RELIEF PEQUESTS NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION DOCKET NO. 50-298 i i

INTRODUCTION By letter dated May 25, 1990, Nebraska Public Power District submitted wo )

relief requests concerning the inservice pump and valve testing program for '

Cooper Nuclear Station. Relief Request RP-14 requested relief from the requirement of pump inlet pressure. Relief Request RP-15 requested re, lief from the requirement of instrument range.

DESCRIPTION AND DISCUSSION >

Relief Request Number RP-14

, The licensee has requested relief from measuring the inlet pressure, before  !

pump start-up and during the test for Service Water Gland Water Supply, SW-P-GWSA, SW-P-GWSB, SW-P-GWSC, SW P-GWSD, RHR Service Water Booster Pump

! Gland Water Supply, SW-P-BPGWSA, SW-P-BPGWSB, SW-P-BPGWSC, SW-P-BPGWSD, in i accordance with the requirements of Section XI, Paragraph IWP-3100, and proposed to calculate pump inlet pressure.  ;

Basis for Relief No inlet pressure. instrumentation is provided.

Evaluation These pumps take suction from their respective Service Water Gland Water l Transfer tanks or the RHR Gland Water Transfer tanks. The. inlet pressure is due to the head of water above the level of the aump inlet. The inlet pressure '

I when the pump is operating cannot be determined >ecause there are no installed inlet pressure instruments and the level of the medium remains essentially constant throughout the test. However, significant blockage in the pump suction would be indicated by a reduction in the pump flow rate. In addition, calculation of the pump inlet pressure by measuring the water level above the pump suction will allow the licensee to determine the pump differential pressure.

Using the calculated pump differential pressure in conjunction with the pump flow rete should provide adequate information to ascertain the hydraulic condition of the pump and to detect any pump hydraulic degradation.

A system modification would be necessary to allow direct measurement of pump inlet pressure and the additional information provided would have a minimal impact on the licensee's ability to detect pump hydraulic degradation. Based 9009100117 900831 PDR ADOCK 05000298 p PDL

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on the impracticality of these measurements, the burden on the licensee if i these Code requirements were imposed, and the licensee's proposed alternate testing of measuring water level and calculatin maybegrantedpursuantto10CFR50.55a(g)(6)(g)pumpinletpressure,

1. relief  ;

Relief Request Number RP-15 The licensee has requested relief for Reactor Equipment Cooling, REC-P-A, REC-P-B, REC-P-C, REC-P-D from the requirement of the ASME Code,Section XI, IWP-4120 which requires that the full scale range of each instrument shall be 1 three times the reference value or less. The licensee proposed to utilize  !

installed flow indicators REC-FI-450A and REC-FI-450B.

l Basis for Relief  ;

The installed instrumentation, REC-FI-450A and REC-FI-4508 used by the j i

licensee to measure REC pump flow rate provide an accuracy which is  ;

equivalent to the Code requirement. ,

Evaluation The Code requires an instrument accuracy of 12% for the instrument used to t measure flow rate and that its full-scale range be three times the reference value or less. The licensee indicated that tie installed permanent flow -

instruments have ranges of 0-4000 gpm and the respective reference value is 1000 gpm. The instrument range exceeds the respective reference value by '

greater than a factor of three. However, the accuracy of these instruments is  :

11.5% which could be as large as 160 gpm. An instrument accuracy of t60 g ,

on a full range of 0-3000 ppm (3X1000 gpm) would be *2% of the full range.pm Therefore, the licensee's proposed range and accuracy results in data .

measurenent of essentially equivalent accuracy to that provided by the Code.

requirements and should provide reasonable assurance of component operational >

readiness. It would be burdensome to require the licensee to install new flow rate instrumentation and it may not provide better indication accuracy or a commensurate increase in safety. Therefore, the relief may be granted pursuant to10CFR50.55a(a)(3)(11).

CONCLUSION Based upon the above review, the staff has determined that Relief Requests RP-14 and RP-15 may be granted 50.55a(a)(3)(ii}, respectively, pursuant and thattothe 10granting CFR 50.55a(g)(6)(1) of such reliefand is 10 CFR authorized by law, will not endanger life or property, or the common defense and security, and is otherwise in the public interest. This relief was granted giving due consideration to the burden on the licensee if the code requirments were imposed on the facility.

Dated: August 31, 1990 Prinicip61 Contributor: Y.C. Li l - - . - . - - - . - - . - - - -