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Nuclear Power Plant Pump and Valve,

and Dynamic Restraint (Snubber)

Inservice Testing Issues

Gurjendra S. Bedi, P. E.Division of Component Integrity

Office of Nuclear Reactor Regulation

J uly 14-15, 2008


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Introduction

Pump, valve, and snubber inservice testing (IST)issues have occurred since Ninth NRC/ASME

Symposium on Pump and Valve Testing, J uly 2006:

Smooth-running pump vibration issues Safety relief valve (SRV) testing frequency issues

Check valve sample disassembly and inspection

on-line Use of 10 CFR 50.59 processes to change the

NRC authorized relief requests related to inservice

inspection and testing


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Smooth-Running Pump Issues

Background

Licensees prefer to use smooth-running pumpvibration criteria in inservice testing (IST) to reduce

unnecessary corrective action.

Informally, when vibration reference values arebelow 0.05 inch/second, pumps are called

smooth-runningpumps.

Licensees have submitted relief requests to usealternative vibration acceptance criteria on a case

by case basis when vibration reference value isbelow 0.05 in/sec.


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Smooth-Running Pump Issues (continued)

The ASME OM Code Requirements

ISTB-5121(e) and ISTB-5123(e) require the measured vibrationshall meet the applicable acceptance criteria as specified inTables ISTB-5100-1, ISTB-5200-1 or ISTB-5300-1.

The acceptable vibration criteria of ISTB Tables require that, ifduring an IST test, vibration exceeds 2.5 times the previouslyestablished reference value (Vr), the pump is considered in thealert range.

ISTB-6200(a), Alert Range Criteria, states that the pump ISTfrequency is doubled until cause of the deviation is determinedand condition is corrected.

Pumps with vibration values > 6Vr are considered in the required

action range & must be declared inoperable until corrected.


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Smooth-Running Pump Issues (continued)

Discussion

NRC staff has authorized alternative vibrationacceptance criteria for smooth-running pumps on

case by case basis.

Recently, some licensees have are submitted ageneric relief request for all the pumps at their

plant. NRC is not in position to authorize generalrelief for all pumps, should they be determined tobe smooth-running pumps.

Relief will considered on a pump-specific case bycase basis.


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Safety Relief Valve (SRV) Testing Frequency

Issues

Background

Some licensees are performing IST of SRVs beyondthe 5 year testing requirement of the Code.

Some licensees are using an SRV installation-to-testtime duration of 5 years to meet the Code requirement.

Some licensees are not including SRV storage time inthe test-to-test duration time, resulting in elapsed timebetween two consecutive tests of more than 5 years.


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SRVs Testing Frequency Issues (continued)

The ASME OM Code Requirements

Appendix I, Paragraph I-1320 requires that Class 1 pressurerelief valves to be tested at least once every 5 years. Thismeans SRV test-to-test time duration is limited to 5 years.

ASME OM-1-1989, Section 1.3.1, requires that Class 1 pressurerelief valves be tested at least once every 5 years. The testinterval for any individual valve must not exceed 5 years.

ASME Code Interpretation 01-18, ASME OM Code -1995 withOMa Code-1996 Addenda, Appendix I,dated J une 26, 2003,clarifies the start of the 5-year test interval. The ASME OM CodeCommittee position is that the 5 year test interval starts when the

valve is tested, not when the valve is installed.


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Discussion NRC staff has authorized extension of the SRVs IST

beyond 5 years on a case by case basis, with thefollowing justification:

SRVs are routinely refurbished, which providesreasonable assurance that setpoint drift is minimum.

SRVs are stored in a controlled environment, whichhas minimum effect on the set point; and

SRVs have satisfactory past performance for

meeting the set point acceptance criteria.


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Discussion (cont.)

Licensees are requested to carefully examine theinterval or frequency of the IST of SRVs, keeping

in mind the ASME Code requirement that Class 1valve be tested at least once every 5 years. Thismeans that the SRV test-to-test interval shall notexceed 5 years.

Technical Specification (TS) may allow plantowner to operate the plant when 5 yearsurveillance is missed, provided certain TS

conditions are met.


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Check Valve On-line Disassembly and

Inspection

Background

Licensees often prefer check valve on-line IST toreduce refueling outage time.

Licensees have submitted relief requests toperform IST of check valves to disassemble andinspect on-line.

Some licensees have submitted relief requests touse a sample disassembly examination program

for a group of check valves on-line.


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Inspection (continued)

The ASME Code Requirements ISTC-3510 requires that check valves be exercised

nominally every 3 months.

ISTC-3522(c) allows check valves exercisingduring refueling outages, where exercising is notpracticable during operation at power.

ISTC-5221(c) allows disassembly of sample checkvalves from a group of identical valves in similarapplication.

ISTC-5221(c)(3) states that all valves in eachgroup shall be disassembled and examined at leastonce every 8 years.


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Discussion

NRC staff has authorized on-line testing of checkvalves on a case by case basis.

On-line check valve disassembly and examinationwill be performed at least once each operating cycleon a refueling outage frequency.

ISTC-5224 requires that, if a check valve fails insample disassembly program, all check valves insample group are to be examined during the samerefueling outage. Licensees can not defer

disassembly and inspection of other check valves inthe group.


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Discussion (cont.)

On-line sample disassembly and inspection IST

activities for check valves in a group is notrecommended unless the allowed outage time(AOT) provides sufficient time to permit theinspection of all valves in the group, if needed.

NRC staff has found on-line disassembly andinspection of check valve groups containing one

valve acceptable.


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Use of 10 CFR 50.59 Process to Change the

NRC Authorized IST Relief Request (RR)

Background In accordance with 10 CFR 50.55a, the NRC has

approved alternatives and granted numerous reliefsfrom the ASME Code requirements related to

inservice examination and testing of variouscomponents including pumps, valves & snubbers.

The use of an alternative as authorized by the NRC

becomes a regulatory requirement. NRC has learned that at least one licensee used

the 10 CFR 50.59 process to revise an NRCapproved alternative related to snubber inserviceexamination and testing.


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Use of 10 CFR 50.59 Process to Change

the NRC Authorized IST RR (continued)

Regulations 10 CFR 50.59 requires licensees- To evaluate proposed changes to their facilities for their

effects on the licensing basis of the plant, as described in theFinal Safety Analysis Report (as updated), and

- To obtain prior NRC approval for changes that meetspecified criteria (10 CFR 50.59) as having a potentialimpact upon the basis for issuance of the operating license.

NEI-96-07, Revision 1, Guidelines for 10 CFR 50.59Implementation, requires that the licensees activities controlled byregulation 10 CFR 50.55a, take precedence over 10 CFR 50.59.

NEI-96-07 is endorsed by Regulatory Guide 1.187, Guidance for

Implementation of 10 CFR 50.59, Changes, Tests, andExperiments.


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Discussion

The licensees are encouraged to be cautiouswhen revising or changing programs orprocedures referenced in an approved reliefrequest.

Any change or updates that supersedes oroverwrites an alternative authorized in a relief

request must be approved by the NRC.


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Discussion (cont.)

10 CFR 50.59 process can not be used to revise

an alternative as authorized by the NRC.Licensees are requested to resubmit their reliefrequest with revised alternative to NRC for review.

10 CFR 50.59 process can not be used to reviseportions of licensee controlled documents such asTechnical Requirement Manual (TRM) forsnubbers examination and testing, which wereauthorized by NRC as an alternative in lieu of theCode requirements.


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Conclusions

The purpose of this paper is to make licenseesaware of a number of pump, valve and snubberissues that staff has encountered since the Ninth

NRC/ASME Symposium on Pump and ValveTesting in J uly 2006. Licensees who believe thatsome of the items discussed are applicable to their

facilities may wish to review their current ISTprogram and modify their program as appropriate.

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