NG-98-2056, Comment Supporting Proposed Rulemaking to 10CFR50.65, Requirements for Monitoring Effectiveness of Maint at Npps. Author,However Have Some Concerns Re Proposed Rule Language Itself

Comment Supporting Proposed Rulemaking to 10CFR50.65, Requirements for Monitoring Effectiveness of Maint at Npps. Author,However Have Some Concerns Re Proposed Rule Language Itself

ML20198J063
Person / Time
Site:	Duane Arnold
Issue date:	12/14/1998
From:	Peveler K IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	Hoyle J NRC OFFICE OF THE SECRETARY (SECY)
References
FRN-63FR52201, RULE-PR-50 63FR52201-00028, 63FR52201-28, NG-98-2056, NUDOCS 9812300080
Download: ML20198J063 (3)

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DO ti ~iD 1 ALLI ANT 'T" lEN 1"c-UTluTIES Duane Arnold Energy Wnter IES Utilities 9g gygg gDgi Offwe: 319 IGIIM i Fax:319.831398t>

www.alhant energttom December 14,1998 NG-98-2056 #s-Mr. John C. Hoyle' Secretary of the Commission DOCKET N Attention: Rulemakings and Adjudication's Staff PM M N 50 U. S. Nuclear Regulatory Commission [63FR5ppo/)

Mail Station 0-PI-37 Washington, D. C. 20555-0001 ,

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Subject:

Duane Arnold Energy Center l Docket No: 50-331 Op. License No: DPR-49 Comments on Proposed Rule Making to 10 CFR 50.65

Reference:

63 Fed. Rec. 52201 - September 30,1998 (Proposed Rulemaking to 10 CFR 50.65, Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants)

File: A-119 The Duane Arnold Energy Center (DAEC, Alliant Energy) has reviewed the proposed rulemaking for 10 CFR 50.65 (the Maintenance Rule, i.e. the " Rule"), which would explicitly apply the Rule to normal shutdown operations, modify a recommendation for an assessment of equipment out of service to a regulatory requirement for an assessment of plant configuration prior to any maintenance activity, and require consideration of the above assessment result to ensure the plant is not placed in a risk-significant condition or that configurations occur that would degrade the performance of safety functions to an unacceptable level.

The purpose of the above proposal is clearly to ensure acceptable plant configuration control during power and shutdown operations, which is a concept DAEC wholeheartedly supports. DAEC has always treated the existing Rule language for such reviews as a requirement, and currently has configuration assessment programs for both online and refueling outage conditions to ensure plant risk is minimized.

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. Mr. John C. Hoy el _

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- We do, however, have some concerns regarding the proposed Rule language itself. At DAEC, when a safety system, train or large component is taken out of service, many maintenance tasks may be performed concurrently on it or its supporting components in order to limit the total time during which the item is unable to perform its function. Prior to removing the system, etc. from service, our plant considers the effect of the action on plant risk, based on the current plant configuration and the ongoing availability of other systems, trains, and large components. This approach is in accordance with the current recommendation of paragraph (a)(3) of the Rule.

In contrast to the approach outlined above, the proposed Rule addition of paragraph (a)(4) could be understood to imply that for the scores of maintenance activities undertaken during any given week (generally on a few select systems) a documented and uniform description of the effect of each and every individual activity on overall safety function performance and on plant risk must be performed using established risk analysis techniques such as Probabilistic Risk Assessment. To require this level of discreet, detailed analysis would be burdensome, would provide little additional information with respect to limiting risk, and could be viewed as counterproductive to safety in that it would distract resources and attention from more important activities. The performance of a single analysis for the effect of removing a system, train or large component from service, regardless of what specific maintenance actions are to be undertaken on it, provides the same safety benefit with far less burden. We would recommend the proposed Rule language be clarified in this regard.

In addition, within the proposed paragraph (a)(4) modification, the precise meaning of the new phrases " risk-significant configurations" and " configurations that would degrade the performance of safety functions to unacceptable level" are not clear, and could be subject to interpretation. The meaning of such phrases should be explicit prior to the revised Rule's implementation.

We would also like to point out that the Rule in its current form already contains a

. provision which requires a performance-based assessment of the effectiveness of a plant's maintenance program. Adjustments are to be made if there is not an acceptable balance between the equipment out-of-service time (often for preventive maintenance) and the reliability of the equipment. This ongoing ba!ancing activity helps ensure that equipment is not taken out-of-service for excessive periods, which also serves to reduce risk.

The Nuclear Energy Institute (NEI) has also provided comments regarding the NRC's

, proposal, and DAEC would like to take this opportunity to endorse NEl's i recommendations regarding both the proposal's specifics and the general concept of making the Maintenance Rule more risk-informed, and we encourage their close review.

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Mr. John C. Hoyle December 14,1998 NG-98-2056 Page 3 of 3

We agree that staff guidance for inspection and enforcement of the proposed Rule modifications should also be available for consideration prior to approval of the Rule change. Also of note is NEI's comment with respect to 10 CFR 50.65 scoping

implementation and an apparent regulatory emphasis, thus far, on components oflow risk significance. This current emphasis has a considerable impact when examining the potential effect of proposed Maintenance Rule changes. In DAEC's case,107 of 170 l systems in the plant are within the scope of the current Rule. Of these 107 in-scope systems,56 are safety-related,51 are considered to be risk-significant, and 36 are both safety-related and risk-significant. Thus, fully one third of the systems which are l considered within the scope of the current Rule (36 of 107) are neither risk-significant nor

safety-related. This does not appear to place application of the Rule in a very risk-i informed setting.

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, If you have any questions regarding this inatter, please feel free to contact this office.

Sincerely, i

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l Ken Peveler Manger, Regulatory Performance cc: R. Murrell E. Protsch J. Franz

D. Wilson R. Laufer (NRC-NRR)

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