ML20058H022

Safety Evaluation Accepting Licensee Proposed Alternative to ASME Code Requirements in PRR 15,per 10CFR50.55(a)(3)(i). Denies Pump Relief Request 14

ML20058H022
Person / Time
Site:	River Bend
Issue date:	11/30/1993
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20058H000	List: ML20058G997 ML20058H022
References
NUDOCS 9312100235
Download: ML20058H022 (5)

Text

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k# Rf C 7% UNITED STATES h )*d

1. I E NUCLEAR REGULATORY COMMISSION

[ WASHINGTON, D.C. 20555-0001 Qg [ u[ /

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATIQH BELATED TO THE INSERVICE TESTING PROGRAM RELIEF RE0 VESTS GULF STATES UTILITIES COMPANY RLVER BEND STATION. UNIT 1 DOCKET NO. 50-458

1.0 INTRODUCTION

By letter dated September 14, 1993, Gulf States Utilities Company (GSU) submitted pump relief requests (PRR) 14 and 15 as part of the River Bend Pump and Valve Inservice Testing (IST) Program Plan, Revision 6. The licensee's IST program covers the first ten-year interval from June 16, 1996, to June 16, 1996. The River Bend Station, Unit 1, (RBS) IST program was developed in accordance with the 1980 Edition of ASME Section XI through the Winter 1981 Addenda.

2.0 BACKGROUND

The Code of Federal Regulations,10 CFR 50.55a, requires that inservice testing (IST) of certain ASME Code Class 1, 2, and 3 pumps and valves be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable addenda, except where relief has been requested and granted or proposed alternatives have been authorized by the Commission pursuant to 10 CFR 50.55a(f)(6)(i), (a)(3)(1), or (a)(3)(ii). In order to obtain authorization or relief, the licensee must demonstrate that (1) conformance is impractical for its facility; (2) the proposed alternative provides an acceptable level of quality and safety; or (3) compliance would result in a hardship or unusual difficulty without a compensating increase in the level of quality and safety. Section 50.55a(f)(4)(iv) provides that inservice tests of pumps and valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in 10 CFR 50.55a(b), subject to the limitations and modifications listed, and subject to Commission approval. NRC guidance contained in Generic letter (GL) 89-04,

" Guidance on Developing Acceptable Inservice Testing Programs," provided alternatives to the Code requirements determine) to be aceptable to the staff and authorized the use of the alternatives in Positions 1, 2, 6, 7, 9, and 10 provided the licensee follows the guidance delineated in the applicable position. When an alternative is proposed which is in accordance with GL 89-04 guidance and is documented in the IST program, no further evaluation is required; however, implementation of the alternative is subject to NRC inspection.

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Section 50.55a authorizes the Commission to grant relief from ASME Code requirements or to approve proposed alternatives upon making the necessary findings. The NRC staff's findings with respect to granting or not granting '

the relief requested or authorizing the proposed alternative as part of the licensee's IST program are contained in this safety evaluation (SE).

In rulemaking to 10 CFR 50.55a, effective September 8,1992, (see 57 TR  ;

34666), the 1989 Edition of ASME Section XI was incorporated in '

10 CFR 50.55a(b). The 1989 Edition provides that the rules for IST of pumps and valves shall meet the requirements set forth in ASME Operations and Maintenance Standards Part 6 (OM-6), " Inservice Testing of Pumps in Light-Water Reactor Power Plants," and Part 10 (OM-10), " Inservice Testing of Valves in Light-Water Reactor Power Plants." Pursuant to 10 CFR 50.55a(f)(4)(iv),

portions of editions or addenda may be used provided that all related '

requirements of the respective editions or addenda are met, and subject to Commission approval. Because the alternatives meet later editions of the Code, relief is not required for those inservice tests that are conducted in accordance with OH-6 and OM-10, or portions thereof, provided all related requirements cre met. Whether all related requirements are met is subject to NRC inspection.

3.0 RELIEF RE0 VESTS Pumo Relief Reouest Number 14 The licensee has requested relief from the inservice test procedure requirements specified in ASME Section XI, Table IWP-3100-1, for line fill pumps in the following systems: high pressure core spray, IE22*PC003; residual heat removal - low pressure coolant injection, IE12*PC003; low pressure core spray, IE21*PC002; and reactor core isolation cooling, IE51*PC003. The licensee has proposed to measure all test quantities listed in Table IWP-3100-1 with the exception of differential pressure. (Note: Pump Relief Request Number 10 already grants relief from the requirement to take pump bearing temperature for these pumps.)

Licensee's Basis for Reouestina Relief: The licensee states that the line fill pumps' function is to keep the main emergency core cooling systems (ECCS) and reactor core isolation cooling (RCIC) pump discharge piping full of water.

These line fill pumps operate continuously whenever their respective main pump and system is in an operable condition; therefore, testing for operational readiness of these pumps is not required. Adequate verification of their intended function is provided by the control room switch panels with annunciator signals and panel lights if the pressure were to drop to a preset value. In addition, RBS technical specifications require a verification every 31 days that the main ECCS and RCIC pump discharge piping is filled with water 1 by venting the piping at the high point vents.

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Licensee's Proposed Alternative Testino: The licensee proposes that since the pumps are continuously running while the systems are operable, no additional quarterly testing will be performed. The pumps performance will be monitored on a quarterly frequency by obtaining operating performance parameters (i.e.,

suction pressure, flow rate, oil levels, and visual inspection for leaks) and vibration monitoring, and recording the results in the record of tests. These parameters will have acceptance, alert, and required ranges to establish proper trending for component degradation.

Evaluation The ASME Code,Section XI, Subsection IWP, requires that safety-related pumps be tested quarterly to verify their operational readiness. Routine testing gives an indication of current pump condition and identifies any trends in pump degradation so timely corrective action can be taken on a degraded pump prior to a catastrophic failure. The Code, IWP-3400(b), does not require a special inservice test for pumps that operate more often than the required testing frequency provided the plant log shows each such pump was operated at least once every 3 months at the reference conditions, and the quantities specified by the Code are measured, observed, recorded, and analyzed.

The line fill pumps are continuously running when the ECCS and the RCIC are operable. These pumps function to maintain a positive pressure in the associated ECCS and PCIC piping. The ECCS and RCIC line pressures are monitored in the contrel room and will alarm if any line pressure falls below the set pressure. The licensee has proposed to monitor all pump parameters specified in Table IWP-3I00-1 quarterly, with the exception of differential pressure. The licensee did not provide any justification in their relief request as to why differential pressure could not be measured. In the Updated Safety Analysis Report (USAR), the ECCS and RCIC piping and instrument schematics show differential pressure taps across each of the line fill pumps.

However, the USAR schematics do not show any differential pressure measurement instrumentation installer at any of these locations.

Trending of pump hydraulic performance data requires at least one established reference value for either pump differential pressure or flow rate. With the reference value set, the other parameter is measured to determine the extent of any degradation of pump hydraulic performance. Since the licensee's proposed testing does not include provisions to monitor differential pressure during any test, adequate trending data to predict pump hydraulic condition will not be taken. In addition, the licensee's relief request does not address why the line fill pumps cannot be tested during cold shutdowns. It may be possible to install temporary instrumentation quarterly or during cold shutdowns to measure differential pressure.

The licensee's submittal of PRR I4 does not provide justification for not measuring pump differential pressure. In addition, the licensee did not provide information on how the pump hydraulic condition will be evaluated after each test without measuring pump differential pressure. Finhily, the

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licensee did not address testing these pumps during cold shutdowns.

Therefore, relief cannot be granted as requested.

Conclusion The licensee's relief request is denied. The licensee should either test the i line fill pr.ps in accordance with the Code requirements or investigate testing the pumps during cold shutdowns. In addition, this relief request should be revised, if resubmitted, to include adequate justification for nut measuring p1mp differential pressure quarterly.

Pump Relief Recuest Number 15 The licensee has requested interim relief from the flow measurement .

requirements of ASME Section XI, Paragraph IWP-4600, for the emergency diesel generator fuel oil transfer pumps, IEGF* PIA, IEGF*PIB, and IEGF*PIC. The licensee stated in their September 14, 1993, letter, that relief was requested to be granted on an interim basis pending the approval of a Code Case. The licensee has proposed to calculate an average flow rate by using the day tank level instrumentation.

Licensee's Basis for Reauestino Relief: The licensee states that the purpose  !

of the emergency diesel generator fuel oil transfer pump is to pump fuel from  !

the storage tank to the emergency diesel generator fuel oil day tank. There are no flow instruments installed in the fuel oil system. The inservice test requirement is to obtain a flow rate which is achieved by a measurement of level of the storage tank and a volume change versus time to indicate a flow .

rate.

Licensee's Proposed Alternative Testino: The licensee proposes that to obtain the required flow rate, the use of level instrumentation over a specific time period will be used to calculate the flow rate. This calculation will be .

documented in the record of test on a quarterly basis. The level instrument will meet the accuracy and range specified in IWP-4100.

Evaluation l The Code, IWP-4600, requires that the pump flow rate shall be measured using a rate or quantity meter installed in the system. The emergency diesel generator fuel oil transfer pumps do not have flow meters currently installed in the system. The licensee has proposed to calculate the pump flow rate by determining the time to fill a predetermined volume of the day tank. The licensee's proposed method of testing results in the calculation of an average flow rate as compared with an instantaneous flow rate that would be measured with flow instrumentation in the piping circuit. The Code does not make a distinction between average and instantaneous flow rates but does require that the instrument measuring the flow rate be accurate to f2 percent of the full-scale range of the instrument. The licensee stated in their relief request that the level instrument used will meet the Code accuracy requirements of.

Table IWP-4110-1. The accuracy of the level instrument is subject to i i

verification by inspection. Therefore, the licensee's proposed alternate  !

method of testing provides an acceptable level of safety.

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9' In the September 14, 1993, letter the licensee requested that PRR 15 De granted on an interim basis pending the outcome of a Code Case. The staff I contacted the ASME staff to check on the status of the aforementioned Code Case and determined that no action is currently underway in the Code on this subject. However, since the licensee's proposed alternate method of testing provides an acceptable level of safety, the staff has determined that the proposed alternative is acceptable for long-term relief. Depending on the action of the ASME Code Committee, this method may be determined to meet the Code at some future date. At that time, the licensee may withdraw this relief request and note the basis for the withdrawal in their IST program.

Conclusion The proposed alternative to the Code requirements to mea.yrt he flow rate by i determining the change in tank level over a period of time ; authorized pursuant to 10 CFR 50.55a(a)(3)(1) based on the alternative providing an acceptable level of quality and safety. j

4.0 CONCLUSION

The staff has determined that the proposed alternative to the ASME Code requirements in PRR 15 provides an acceptable level of quality and safety and therefore authorizes its use pursuant to 10 CFR 50.55a(a)(3)(1). Pump Relief Request Number 14 is denied. The licensee should either submit a response to the evaluation in this relief request within 3 months of the date of this SE or perform testing of the line fill pumps in accordance with the Code requirements.

Principal Contributor: Joseph Colaccino Date: November 30, 1993

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