ML20058H628

Safety Evaluation Granting IST Program Requests for Relief

ML20058H628
Person / Time
Site:	Millstone
Issue date:	12/02/1993
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20058H609	List: ML20058H608 ML20058H628
References
GL-89-04, GL-89-4, NUDOCS 9312130158
Download: ML20058H628 (9)

Text

i

}ja asog'o,

+

_)"(

E UNITED STATES

% $[

NUCLEAR REGULATORY COMMISSION j

gv,#

WASH NGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE INSERVICE TESTING PROGRAM RE0 VESTS FOR RELIEF NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION. UNIT 1 DOCKET NO. 50-245 i

1.0 INTRODUCTION

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)(i), or (a)(3)(ii).

In order to obtain authorization or relief, the licensee must demonstrate that:

(1) l 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) 09-04,

" Guidance on Developing Acceptable Inservice Testing Programs," provided alternatives to the Code requirements determined to be acceptable to the staff and authorized the use of the alternatives in Positions 1, 2, 6, 7, 9, and 10 provided the licensee follow 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.

I Section 50.55a authorizes the Commission to grant relief from ASME Code requirements or to approve proposed alternatives upon making the necessary t

findings. The NRC staff's findings with respect to granting or not granting the relief requested or authorizing the proposed alternative as part of Northeast Nuclear Energy Company's (NNEC0/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 Federal Register 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 9312130158 931202 PDR ADOCK 05000245 P

PDR r

in Light-Water Reactor Power Plants." Pursuant to 10 CFR 50.55a(f)(4)(iv),

j 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 OM-6 and OM-10, or portions thereof, provided all related r

requirements are met.

Whether all related requirements are met is subject to i

NRC inspection.

2.0 BACKGROUND

By letter dated October 30, 1992, NNECO provided the NRC staff with their resolution of the outstanding items regarding the third 10-year interval IST program for Millstone Unit 1.

This was in response to the staff's January 8, i

1992, safety evaluation, which reviewed Revision 4 of the Millstone Unit 1 IST Program and associated relief requests.

In the January 8, 1992, safety evaluation, the staff requested NNECO to address several action items.

NNECO's October 30, 1992, submittal addressed these items and, in addition, forwarded Revision 5 of the IST program.

In a letter dated February 18, 1993, the staff issued its review of Revision 5 of the Millstone Unit 1 IST Program. The safety evaluation granted and denied several relief requests, as well as requested additional information. NNECO's August 16, 1993, submittal included their assessment of the remaining j

outstanding items for the third 10-year interval. Revised relief requests were submitted which are evaluated below. Table I lists each relief request and describes actions taken by NNECO and the current status.

l The Millstone Unit 1, IST program covers the third 10-year interval which commenced on August 15, 1991. The program was based on the requirements of the ASME Code,1989 Edition, which was approved by the rulemaking discussed in Section 1.0 above.

r 3.0 EVALUATION 3.1 Relief Reouest R-2 Relief from the requirements of OM-6, paragraph 4.6.1.1, for flow instrumentation accuracy (i 2%) is requested for the feedwater coolant injection / core spray (FWCI/CS) pumps.

3.1.1 Licensee's Basis for Relief d

The licensee states:

The flow measurement equipment configuration currently installed has analog indicators and does not allow for a loop accuracy of 2%.

The current loop accuracy is 2.1%.

This accuracy is not significantly outside the ASME/ ANSI OM-6 limit of 2% and will prnvide repeatable test results to facilitate detection of pump degradation.

l l

I

_3-3.1.2 Alternative Testino The licensee proposes to continue to use installed flow instrumentation.

3.1.3 Evaluation i

OM-6 requires an accuracy of i 2% to ensure that the test data are i

sufficiently accurate for comparisons that would indicate a degrading condition prior to failure.

The installed instrumentation for measuring l

FWC1/CS pump flow has a loop accuracy of i 2.1%.

Therefore, an accuracy of 2% is impractical due to the design limitations of the instrumentation.

Imposition of the Code requirements would be a burden on the licensee because new instrumentation would have to be installed in the system, or portable instrumentation would have to be utilized which may have no better accuracy l

than the currently installed instrumentation. The difference between a i 2%

and a i 2.1% accuracy does not significantly affect the licensee's ability to monitor the pumps for degradation.

3.1.4 Conclusion Relief is granted in accord with 10 CFR 50.55a(f)(6)(1) to use currently installed flow instrumentation for the FWCI/CS pumps based on the impracticality and design limitations in achieving the Code required accuracy and in consideration of the burden on the licensee if the requirements were imposed.

l 3.2 Relief Reouest V-12 The licensee has requested relief from the requirements of OM-10, paragraphs 4.2.2.2, 4.2.2.3, and 4.3.2.1, for the Code Class 2 reactor recirculation containment isolation valves,1-RR-111A/B.

3.2.1 Licensee's Basis for Relief The licensee states:

Each reactor recirculation pump seal flush line consists of inboard containment check valve 1-RR-Illa (B) and check valve 1-RR-Il2A(B).

Currently, there are no test connections available to implement an Appendix J test and verify leak tightness or valve closure.

3.2.2 Alternative Testina The licensee proposes:

Perform a standing water reverse flow leak test or a non-intrusive test at refuel to demonstrate the closure function of the valves.

An exemption request from the requirement of Appendix J is being provided to the NRC staff under separate correspondence.

i l 3.2.3 Evaluation r

The licensee proposes to verify closure by a reverse flow leak test or a non-i intrusive test to meet the requirements of OM-10.

Paragraph 4.3.2.4, " Valve Obturator Movement," allows that observation of closure may be direct indication or by changes in system pressure, flow rate, level, temperature, l

seat leakage testing, or other positive means. A reverse flow leak test and a non-intrusive test both meet the provisions of paragraph 4.3.2.4.

Therefore, i

relief to verify closure by the methods proposed is not required.

Concerning the leak testing requirements for containment isolation, GL 89-04, Position 10, indicated that containment isolation valves subject to Appendix J local leak rate testing should be in the IST program and categorized as Category A.

If an exemption is received which eliminates the local leak rate testing requirements of Appendix J, the valves need not be leak tested per OH-10 unless a leak-tight function other than containment isolation is performed.

Therefore, unless the licensee determines that these valves have another leak-tight function, the disposition of the IST program leak testing requirements will be dependent on the exemption to Appendix J.

No further evaluation is required for the IST program requirements at this time.

3.2.4 Conclusion l

Relief Request V-12 should remain in the IST program until the Appendix J exemption is approved or denied. Approval for the proposed alternative to verify closure is not required, as the Code allows such alternative methods.

Upon a determination of the NRC actions regarding the requirements for local leak rate testing, the relief request should be deleted or modified as necessary.

3.3 Relief Reauest V-10 Relief from the closure verification and leak testing requirements of OM-10 was granted for an interim period until test connections could be installed in the Cycle 15 refueling outage (1996). NNEC0 has revised Relief Request V-10 based on further review, removing Valves SA-344 and SA-345 from the relief request. A standing water reverse flow leakage test will be performed to verify closure of valve CU-29 during refueling outages until the modifications are complete which will allow testing of CU-29. The interim relief granted per 10 CFR 50.55a(f)(6)(i) in the February 18, 1993, safety evaluation remains i

applicable for valve CU-29.

4.0 CONCLUSION

Based on the review of the Millstone Nuclear Power Station, Unit 1, IST Program revi.sions and relief requests, the NRC staff concludes that relief as

)

evaluated and modified by the SE wili provide reasonable assurance of the operational readiness of the pumps to perform their safety-related functions.

The NRC staff has determined that granting relief pursuant to 10 CFR 50.55a i

. (f)(6)(1) is authorized by law and will not endanger life or property, or the common defense and security, and is otherwise in the public interest, giving due consideration to the burden upon Northeast Nuclear Energy Company that could result if the ASME Code requirements were imposed on the facility.

Principal Contributor:

P. Campbell Date: December 2, 1993

Table 1 Millstone Nuclear Power Station, Unit 1 Status of Third 10-Year Inservice Testing Program Relief Requests Relief ReqJest Rauber Description and Actions Taken Currer:t Status R-1 R-1 applies to the flow testing frequency of individual Granted per 10 CFR 50.55atf)(6)(1) in the pumps in the service water and feedwater coolant injection 2/18/93 SE.

(FWCI) systems. The pmps witi be monitored quarterly without individual flow measurement, and tested during refueling outages with flow measurements recorded. When flow reference values for the subject pw ps may have been af fected by the repair, replacement, or routine service of the pw ps, new references values for differential pressure and vibration will be recorded and evaluated against past performance of the pw ps until en outage of sufficient duration to rebaseline the prps occurs.

R-2 Flow instrument accuracy for the feedwater coolant injection Granted per 10 CFR 50.55a(f)(6)(i) in the pwps is not within 2% as required by the Code. The 2/18/93 current SE (see Section 3.1).

SE requested WNECO to evaluate the accuracy against ASME OLM Code Interpretation 91-3.

The relief request was revised af ter NNECO determined that the accuracy of the instrunent loop was within 2.1%.

R-3 R-3 concerned the use of flow instrteentation with an Withdrawn.

accuracy of 5% for service water pwp inservice testing.

Based on ASME O&M Code Interpretation 913, the instrtment loop accuracy was determined to be within 21.

R-4 The relief request was applicable to flow instrunentation Interim relief to the 1996 refueling outage for the gas turbine fuel forwarding pwys. The granted in 2/18/93 SE. Relief request instrunentation being instatted during the 1996 refueling withdrawn in Revision 5.

outage is expected to be accurate to within 2%. However, the Licensee has determined that these pwps are not within the scope of the inservice testing program requirements of 10 CFR 50.55a (code Class 1, 2. or 3).

R-5 R 5 discussed the determination of flowrate for the diesel Relief was granted in the 2/18/93 SE, noting generator fuel forwarding pwys and the stancRiy liquid that if the licensee determined the centrol pw ps by means of recording change in tank levet measurement meets the requirements of OM-6, instead of using a rate or quantity meter. NNECO determined retlef was not reg; ired. The relief request that the measurement mes : the requirements for a " rate or has been withdrawn.

quantity meter installed in the pw p test circulta and that the calculations meet tt:e accuracy requirementa in accordance with OM-6.

Therefore, relief is not required.

Relief Reepe st thoder Description and Actions Taken Darent Stattai R6 R-6 concerned the hydraulic acceptance criteria for the gas Because the ptmps are not within the scope of turbine and diesel generator fuel forwarding ptmps. Relief the regulations, NRC approval of any to use whole units was denied in the 2/18/93 SE.

NNECO has associated relief requests is not required for detertained that these pteps are not within the scope of inplementation by the licensee. It is to CFR 50.55a (code Class 1, 2, or 3).

However, the acceptable to include non-Code conponents in croponents will remain in the program, as suggested in NRC the IST program, noting that the components GL 89 04, Position 11.

R-6 will remain in the program, but are non-Code. Testing should conform to the does not regjire NRC approval for inplementation.

requiremmts of the Code, as practical.

R-7 R-7 addressed the use of ptsp performance curves to monitor The licensee has incorporated the provisions the turbine building secondary closed cooling water ptmps of the relief granted in the 2/18/93 SE.

No for degradation. The provisions of the relief granted in further approvst is reqJired.

the 2/18/93 SE have been incorporated into the test procedures; however, when maintenance has been performed which could effect the curves, flow, differential pressure, ard vibration will be recorded and evaluated based on past performances of the pteps until as outage of suf ficient duration to rebaseline the ptmps occurs. To validate a curve at a ntrter of flow rates, a plant shutdown is required.

E8 R-8 involves the range requirements of OM-6 for the Approval was authorized per (a)(3)(1) in the installed pressure gauges used to test the low pressure 2/1B/93 SE.

coolant injection (LPCI) ptmps. The gauges have a larger range, but a tighter accuracy (1% futt scale).

V-1 V 1 proposed an alternative to stroke-time measurements for Approval authorized per (a)(3)(1) in the the emergency service water valves LPC-4A/s. The valves 2/18/93 SE.

will be opence to mid-point and the flow will be monitored.

Motor-operatea valve testing will be performed periodically to measure stroke time and monitor the condition of the valves.

V-2 V-2 proposed to stroke-time test two series valves in the Relief granted per (f)(6)(l) in the 2/18/93 stantby gas treatment system as a pair rather than SE.

Individually. Relief was granted with provisions which have been incorporated in the IST program and will be incorporated in test procedures prior to startup from the Cycle 14 refueling outage.

V-3 V-3 concerned test frequency and obturator movement Provisional relief granted in 2/18/93 SE per verification for the series automatic depressurization (f)(6)(1). Actions being taken by the system check valves and primary nitrogen stopty check licensee adequately address the provisione, valves. The provisions of the relief granted in the previous SE were to repair or replace both of two series valves if acceptance criteria are not met and to ensure that the safety analysis does not require both valves of the pairs. These provisions have been addressed. NNECO reviewed the configurations and determined that only one check valve is required. The applicable procedures are being revised to ensure that both valves will be repaired or replaced if the acceptance criteria is not met.

6 Relief Regsmet Nuder Description arri Actions Taken Current Statum V4 Testing of the control rod drive hydraulic scram valves is Approved per GL 89-04 as noted in 2/18/93 SE.

perforsed in accordance with the guidance in Generic Letter (GL) 89-04, Position 7.

V-5, V-6, and V-7 These relief requests related to testing of the dieset and NRC approval of relief requests for congxments gas turbine systems. Because these systems are not ASME outside the scope of 10 CFR 50.55a is not Code Class systems, approval of the relief requests is not required for inplementation, as discussed in required for implementation. The relief requests will the 2/18/93 SE.

remain in the program to indicate that the testing of these valves does not conform to ASME Code requirements.

V-8 Feedwater coolant injection check valves FW-9A/B and FW-The actions recomended in the 2/18/93 SE have 10A/B will be tested in accordance with OM-10, Paragraphs been taken. No further evaluation is 4.2.1.5 and 4.3.2.2.

A cold shutdown / refueling outage required.

Justification has replaced the relief request.

V-9 The relief request related to stroke timing of the power-Relief Request V-9 has been withdrawn. The operated main steam relief valves which function as open item from the 2/18/93 SE is closed. The automatic depressucitation systeve TADS) valves. The relief ASME O&M Comittee for OM-1 has indicated that request has been withdrawn and the vatves have been they will be aM ressing the categoritation of recategorized from B/C to Category C.

Testing conplies with the ADS valves.

CH-10 and OM-1 requirements for Category C valves.

V-10 Relief from the closure verification and leak testing the interim relief granted per (f)(6)(1) in requirements of OH-10 was granted for en interim period the 2/18/93 SE remains aplicab.s for valve until test connections could be installed in the Cycle 15 CU-29.

refueling outage (1996). NNECO has revised the relief request based on further review. Valves SA-344 and SA-345 have been removed from the relief request. A standing water reverse flow teakage test will be performed during refueling outages until the modifications are conplete which will attew testing of C0-29.

V-11 V 11 covers the check valves which are verified functional The 2/18/93 SE indicated that the relief by disassepbly and inspection in lieu of testing. The reg;est was approved per GL 89-04, provided disassembly and Inspection samling program is in accordance the guidance delineated in Position 2 was with GL 89-04, Position 2.

followed. NNECO indicates that the program is in accordance with the guidance.

V-12 Relief from the leak testing requirements of OM-10 was Relief is not required to verify closure of granted for an interim period until test connections could the apoticable valves by the proposed method.

be installed for reactor recirculation check valves RR-Depending on whether en exemption from 111A/B. M alternative method has been developed that A m endix J is received, the relief request partially meets OM-10 requirements. Therefore, V-12 was should be deleted or modified at a later date.

revised and submitted for review.

See section 3.2 of the SE.

V-13 V-13 referred to the disassently and inspection of non-Code Relief was granted per GL 59 04 as noted in gas turbine fuel forwarding check and Corte Class 3 TBSCCW the 2/18/93 SE. V-13 remains in effect until check valves. NNECO will withdraw V-13 based on a the nedificaticos to instatt flow determination that design accident flow can verify futt-Instrmentation for the system pumps is stroke of the valves following Cycle 14 refueling outage

complete, when pu m flow instrumentation will be instatted.

i 9

Relief Revywst thsder Description erwt Actions Takm Current Status V-14 V-14 refers to the disassently and inspection of the low Relief es approved per GL 89 04. as noted in pressure coolant injection discharge check valves L-11A/8.

the 2/18/93 SE.

NNECO indicates that the program is in accordance with GL 89-04, Position 2.

.=

m.

" ' ' * " ' " ^ ' '

~ -

~ ~ ~ ~ ~

~ ^

~"