NG-95-0464, Comment on Proposed Rule 10CFR50 for Shutdown & low-power Operations for Nuclear Power Reactors

Comment on Proposed Rule 10CFR50 for Shutdown & low-power Operations for Nuclear Power Reactors

ML20078N975
Person / Time
Site:	Duane Arnold
Issue date:	02/03/1995
From:	Keith Young IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	Hoyle J NRC OFFICE OF THE SECRETARY (SECY)
References
FRN-59FR52707, RULE-PR-50 59FR52707-00049, 59FR52707-49, NG-95-0464, NG-95-464, NUDOCS 9502160212
Download: ML20078N975 (3)

Text

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, IES UTILITIES INC. DOCKETED USHRC February 3,1995 i NG-95-0464 '95 FEB 13 P4 :11 l Mr. John C. Iloyle, Acting Secretary -

U. S. Nuclear Regulatory Commission Attn: Docketing and Sersices Branch h-k_[ ,

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Washington, DC 20555-0001 DOCKET NUMBER PROPOSED RULE N Kb -

Subject:

Duane Arnold Energy Center (DAEC) (5CW9-S=YLO$

Docket No: 50-331 Op. License No: DPR-49 Y IES Utilities' Comments on the Proposed Rule for Shutdown and Low-Power Operations for Nuclear Power Reactors

References:

1) Federal Register Notice 59 FR 52707

2) W. Rasin (NEI) to J. Iloyle (NRC), Comments Regarding Proposed Rulemaking on Shutdown and Low Power Operations for Nuclear Power Reactors, January 24,1995,

3) R. Pinelli(BWROG) to USNRC, "BWR Owners' Group Comments Regarding Proposed Rulemaking to Address Shutdown Safety Issues," BWROG-94166, r December 23,1994.  ;

File: A-106

Dear Mr. Secretary:

In response to the Reference 1 request for comments, IES Utilities would like to offer the following comments on the proposed nile, in addition to endorsing those comments filed by the Nuclear Energy Institute (NEI) in Reference 2 and the BWR Owners' Group (BWROG) in Reference 3.

Specifically, our concerns mirror those of NEl and the BWROG that in many instances the specific wording of the proposed rule is too vague, which will lead to inconsistent inspections and enforcement actions. For example, phrases such as, " provide reasonable assurance... " "as ,

necessary to accomodate unforeseen contingencies...," "any departure from the outage plan . I shall be evaluated k the manner also described above and appropriate measures implemented

[ emphasis added} 11 is this a example that is perhaps the most troubling. Most outage plans have literally tens of thousands of work activities in them. The proposed wording implies that any ,

change in any one of those activities would require a formal, documented evaluation for its impact on the fire risk during shutdown. The rule does not appear to allow for any type of screening for risk significance in complying with this requirement. Not only will this greatly increase the manpower, with expertise in fire analysis and mitigation, needed during outages to perform the hundreds of such evaluations that would be needed, we do not see any commensurate increase in  ;

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NG-95-0464 February 3,1995 Page 2 plant safety from such a requirement. We recommend that a threshold for risk be established such that activities below this threshold would not require any formal evaluation when changed during the course of the outage.

We were active industry participants in the development of NUMARC 91-06 (Guidelines for Industry Actions to Assess Shutdown Management) and have used the guidance for outage planning for each of our three refueling outages since the draft guidelines were published in early 1991. We believe that to codify that guidance would reduce the flexibility that we currently have to properly plan our outages in the most safe and eGicient manner possible. Given the fact that almost no two refuel outages have the exact same scope of work, to be held to rigid requirements for system availability compromises the ability to tailor the outages to the work that needs to be performed while ensuring the availability of the proper safety systems in support of that specific workscope. The amount of redundancy of safety systems required by the rule ollen goes well beyond what is actually needed to ensure plant safety. The rule does not acknowledge or give proper credit for the lower decay heat loads present later in the outage. Consequently, preventative maintenance essential to maintaining the reliability of these safety systems must be scheduled during very specific " windows" during the outage when they would not be required to be available under the rule. These windows are most ollen critical-path times. The result is a ,

needless extension of outages due to having to extend these windows sufliciently to do the preventative maintenance. This overly conservative approach has a significant economic impact, without a commensurate increase in plant safety. The rule, if finalized, should allow the same flexibility as the current NUMARC guidelines, which the StafThas acknowledged has led to improvements in the industry in managing risk during plant shutdown.

A point was made in passing in the BWROG comments that we would like to amplify. The reference plant for the cost-benefit analysis for BWRs was Grand Gulf, a BWR of a much newer design than the Duane Arnold Energy Center (DAEC). Specifically, Grand Gulf has a much larger containment building (i.&, Mark Ill) and has more redundancy in its design (eg, four divisions vs. two divisions of electrical power). These difTerences allow n aintenance activities to be performed under the rule at Grand Gulf with mu6 tess impact than at o! der plants, like the DAEC. In particular, the required plant safety systems are spatially compartnentalized in the Mark III, which means that the impact of the fire prmection requirements unoer the rule are easier to implement. While these design differences do not nave an appreciable diflbrence in the safety benefit to be gained from the rule', they do have a significant difference in the cost of implementing the rule for older plants such as ours that does not have the same flexibility in numbers of systems / divisions that can be used fot " backups" in complying with the requirements  !

of the proposed rule. Thus, the cost to us to impl(ment this rule would be substantially higher than that estimated for Grand Gulf.  !

l 1

' Comparison of outage risk, as measured by the risk of reactor coolant boiling. using the NSAC-175L study (Safety Assessment of BWR Risk During Shutdown Operations. August 1992) as a reference, indicates that the shutdow n risk at the DAEC is compara' ole to other BWRs, and in fact, is lower than the risk at Grand Gulf. The calculated average risk of boiling for the upcoming refuel outage at the DAEC is ~ 1.9E-06/ hour. with a peak risk ,

of ~ 7.6E-05/ hour, as compared to the NSAC-175 results for Grand Gulf of 1.7E-05/ hour (ave.) and 1.0E-01/ hour l (pcak). ]

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, NG-95-0464 February 3,1995 Page 3 Finally, we strongly disagree with the stated reason for this rule, which is to impose a " regulatory footprint on outage safety and codify improvements made by the industry." We view this approach as being very detrimental to the positive working relationship that the industry has had with the Staffin dealing with this complex subject. It would set a precedent that would stifle future voluntary efforts on the part of the industry to work with the Staff to improve safety out of fear ofincreased regulatory burden wxi enforcement exposure by retroStting such a " footprint" to those voluntary efforts. We urgently request the Commission to reconsider the need for this rulemaking.

Sincerely, CW Kekth Young' Manager, Nuclear Licensing KDY/RAB/pjv~

cc: R. Browning J. Franz L.Liu L. Root DOCU