ML20211D678

Forwards Enhanced Relief Request for Inservice Testing Program,Covering Containment Spray Sys Min Recirculator Header Check & Suction Check Valves

ML20211D678
Person / Time
Site:	Maine Yankee
Issue date:	10/14/1986
From:	Whittier G Maine Yankee
To:	Thadani A Office of Nuclear Reactor Regulation
References
GDW-86-233, MN-86-126, NUDOCS 8610220247
Download: ML20211D678 (5)

Text

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0 0 B POMB00M#9' AUGUSTA A t E 04 3 October 14, 1986 O HN-86-126 GDH-86-233 Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Hashington, D. C. 20555 Attention: Mr. Ashok C. Thadani, Director PHR Project Directorate #8 Division of Licensing

References:

(a) License No. DPR-36 (Docket No. 50-309)

(b) MYAPCo Letter to USNRC dated August 7, 1985 (MN-85-139)

Maine Yankee Inservice Testing Program Sutject: Inservice Testing Relief Request Gentlemen:

In Reference (b), Maine Yankee requested and provided a basis for relief from certain tests according to the ASME Code as required by 10 CFR 50.55a(g).

This information was reviewed with Mr. Norman Blumberg, NRC Region I, who requested that further technical justification be submitted to support our request. Accordingly, the enhanced relief request for Maine Yankee's Inservice Testing Program is enclosed.

Please contact us if you have any questions.

Very truly yours, HAINE YANKEE ATOMIC POWER COMPANY hb AV G. D. Whittier, Manager Nuclear Engineering and Licensing GDH/bjp

Enclosure:

(4 Pages)

! cc: Dr. Thomas E. Hurley i

Mr. Pat Sears Mr. Cornelius F. Holden Mr. Norman Blumberg, NRC Region I Mr. Hilliam Schubert

/1 8610220247 861014 PDR

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ADOCK 05000309 I PDR i

CR-16 MAINE YANKEE ATOMIC POWER COMPANY GENERIC RELIEF RE0 VEST Justification for using a fixed reference value versus the results from the previous test for the basis of determining increased test frequencies.

CODE REQUIREMENT

. IHA-3417 states that if, for power operated valves, an increase in stroke time of 25% or more from the previous test for valves with full-stroke times greater than 10 seconds or 50% or more for valves with full-stroke times less than or equal to 10 seconds is observed, test frequency shall be increased to once each month until corrective action is taken, at which time the original test frequency shall be resumed.

RELIEF RE0VESI Relief is requested from the requirement to use the previous test results for the basis of increased test frequency. The use of a fixed reference value determined from the results from several previous tests would be used instead.

BASIS FOR RELIEE Using a fixed reference value provides a more logical and stringent basis for determining increased test frequencies. Adhering to the words of the code as stated above, a valve's stroke time could increase during each test and still be considered acceptable, while in fact, the valve could be failing or, at least, worthy of being tested at an increased frequency.

Using a fixed reference value as a standard would give rise to an increased test frequency much sooner than the standard set forth in the words of the code.

Having a fixed reference value would provide a means for promptly making known whether or not a valve is operating in the normal, alert, or inoperative range. The reference values with corresponding alert and inoperative values may be incorporated into plant surveillance procedures which control valve testing, and therefore, would allow one to immediately assess whether or not a valve is operating satisfactorily.

ALTERNATE BASIS FOR INCREASED TEST FRE00ENCIES If a fixed reference valve is exceeded by either; a.) 25% or more for those reference values greater than 10 seconds, or b.) 50% or more for those reference values less than or equal to 10 seconds, Maine Yankee shall increase that frequency to once a month until the condition is corrected.

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MAINE YANKEE ATOMIC POWER COMPANY VALVE RELIEF REQUEST CR-16 CR-25 NUMBER: V-63 SYSTEM: Containment Spray VALVE: CS-53 DRAHING NO: FM-32A/92A CATEGORY: C CLASS: 2 FUNCTION: Minimum Recirculation Header Check Valve EXEMPT TEST: Q, C, Cp, R BASIS FOR RELIEF: This valve is a six inch check valve which allows minimum recirculation flow from the Low Pressure Safety Injection (LPSI) and Containment Spray (CS) pumps back to the Refueling Hater Storage Tank. To be sure that this valve goes full open and passes the maximum possible flow, four of these pumps would have to be run

) in the full recirculation mode simultaneously.

Operating four of these pumps in the recirculation mode simultaneously would render both trains of LPSI and CS inoperable. Tech. Specs. requires both trains operable during normal plant operation. This would also render

both trains of Residual Heat Removal (RHR) inoperable during cold shutdowns. For these reasons Maine Yankee deems it impractical to perform a full stroke flow test on this valve during normal plant operation and cold shutdowns.

r ALTERNATE TEST: (Qp, D) This valve shall be partially stroked quarterly i during monthly ECCS testing and shall be disassembled, inspected, and manually stroked each refueling outage.

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M AM E Y AVAWEAREWEfeMQWESTM PMY CR-13 CR-25 NUMBER: V-37 SYSTEM: Containment Spray VALVE: CS-93, CS-94 DRAHING NO: FM-32A/92A CATEGORY: C CLASS: 2 FUNCTION: Containment Spray Suction Check Valves EXEMPT TEST: Q, Qp, C, Cp, R BASIS FOR RELIEF: Flow testing these check valves would require operating a 5,000 gpm pump taking suction from the safeguards sump located on the -2 ft. elevation in the containment building. The safeguards sump only holds approximately 400 gallons which is not enough to operate a 5000 gpm pump. The only way to provide enough suction through the safeguards sump would be by flooding the containment building from the -39 ft. elevation to about the 0 ft.

elevation. This would require an enormous amount of water and would submerge many plant components. Maine Yankee considers flow testing these check valves impractical. An alternate test will be performed.

The only other practical method of ensuring that these valves operate satisfactorily is by disassembling the valve and manually operating the clapper. This, however, cannot be done during normal plant operation because isolating these valves would render one train of Low Pressure Safety Injection and one train of Containment Spray inoperable.

The primary grade borated water in these valves is very compatible with the valve internals. These valves are not subject to any vibration induced failures because the RAS sump is only used during an accident.

These valves have been disassembled and manually stroked in the past and have been found to be as good as new.

i Based on past performance and the fact that disassembling these valves requires working in a highly contaminated area with respirators, Maine Yankee feels that disassembling and exercising, alternately, one valve each refueling will provide reasonable assurance that these valves will continue to perform their intended function.

ALTERNATE TEST: (D) Alternately, one valve will be disassembled and exercised every refueling outage. If a degraded condition is found, the valve in the other train will be disassembled and exercised.

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MAINE YANKEE ATOMIC POWER COMPANY CR-18 CR-25 NUMBER: P-5 SYSTEM: High Pressure Safety Injection PUMP: P-14A, P-148, and P-14S CLASS: 2 TEST REQUIREMENTS: The pressure measurement instruments shall have a full-scale range of three times the reference value or less.

BASIS FOR RELIEF: During normal plant operation these pumps are aligned as charging pumps and have a suction pressure of around 30 psia. ASME Section XI requires that the gauge used to measure the suction pressure during inservice pump tests shall have a maximum range of zero to three times the reference value which in this case is 0-90 psia. Also, the accuracy must be within t 2% of full-scale. However, during an accident situation these pumps are re-aligned as High Pressure Safety Injection Pumps and, after a Recirculation Actuation Signal (RAS), take suction from the discharge of the Containment Spray Pumps. In this situation, the suction pressure of the pumps would exceed 90 psia. A suction pressure in excess of 90 psia would damage a 0-90 psia gauge. Therefore, Maine Yankee deems it necessary to use a 0-120 psia gauge to ensure that the gauge will be operable during an accident situation. Also, this 0-120 psia gauge is calibrated to within 1% of full-scale (1.2 psi) as compared to the code required accuracy for the 0-90 psia gauge of i 2% of full-scale (1.8 psi).

Therefore, the 0-120 psia gauge is more accurate than the code requires. The pumps also have a large differential pressure of about 2500 psi. This means that significant variations in suction pressure will cause small percentage changes in differential pressure. For example, a 10 psi error in the suction pressure reading would give a change in differential pressure of only 0.4%. This is well within the code allowed variation of differential pressure of plus 3%

minus 10% of the reference differential pressure.

! ALTERNATE TEST: For the reasons stated above, Maine Yankee will use 1 0-120 psia gaitges to measure the suction pressure on the High Pressure Safety Injection Pumps during j Inservice Testing.

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