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FirstEnergy Nuclear Operating Co., Davis-Besse Nuclear Power Station, Unit 1; Environmental Assessment and Finding of No Significant Impact

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 [Federal Register: May 15, 2000 (Volume 65, Number 94)]
[Notices]
[Page 31021-31022]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15my00-87]

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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-346]


FirstEnergy Nuclear Operating Co., Davis-Besse Nuclear Power
Station, Unit 1; Environmental Assessment and Finding of No Significant
Impact

    The U.S. Nuclear Regulatory Commission (the Commission) is
considering the issuance of an exemption, under certain specified
conditions, from the provisions of (1) 10 CFR part 50, appendix K,
section I.D.1 which requires that accident evaluations use the
combination of emergency core cooling system (ECCS) subsystems assumed
to be operative ``after the most damaging single-failure of ECCS
equipment has taken place;'' (2) 10 CFR part 50, appendix K, Section
I.A.4, which specifies that 1.2 times the American Nuclear Standard
ANS-5 decay heat generation rate for an infinite operating time shall
be used; and (3) requirements of 10 CFR 50.46(b)(5) and
50.46(a)(1)(ii), be applied for Facility Operating License No. NPF-3,
issued to the FirstEnergy Nuclear Operating Company (the licensee), for
operation of the Davis-Besse Nuclear Power Station, Unit 1, located in
Ottawa County, Ohio.
    The Commission is taking an action to approve this request prior to
publication in the Federal Register of its Environmental Assessment and
Finding of No Significant Impact. In accordance with 10 CFR 51.13, the
Commission has determined that emergency circumstances are present to
support the issuance of this exemption prior to publication in the
Federal Register in that failure to act in a timely way would result in
prevention of resumption of plant operation.

Environmental Assessment

Identification of the Proposed Action

    The licensee has requested an exemption from 10 CFR 50.46 and 10
CFR part 50 Appendix K regarding

[[Page 31022]]

proposed modifications to the equipment and procedures for boron
precipitation control (BPC) during long-term operation following loss
of coolant accidents (LOCAs). These modifications would be effective
prior to returning to power following the April 2000 refueling outage.
The proposed action is in accordance with the licensees' application
for exemption dated March 15, 2000, as supplemented by submittal dated
April 3, 2000.

The Need for Proposed Action

    The Code of Federal Regulations at 10 CFR 50.46 provides acceptance
criteria for the ECCS, including long-term cooling requirements in
50.46(b)(5) and an option to develop the ECCS evaluation model in
accordance with appendix K requirements (50.46(a)(1)(ii)). Appendix K
requires that the ECCS remain operable following the most damaging
single failure, and it also specifies the decay heat generation rate
that shall be used.
    In licensee event report (LER) 98-008 (October 1, 1998), Davis-
Besse Nuclear Power Station (DBNPS) reported that for some small-break
LOCAs, initiation of its active method of BPC could cause steam binding
in the suction piping of both decay heat removal (DHR) pumps. As part
of the corrective action for LER 98-008, DBNPS committed to address all
issues related to long-term LOCA BPC, and to complete a related plant
modification by the end of the 12th refueling outage that began in
April, 2000. In response to that commitment, in its March 15, 2000 and
April 3, 2000 submittals, the licensee described a new active primary
method for BPC--an improved auxiliary spray path into the pressurizer.
The licensee also described that a failure anywhere in the flow path
could result in failure of this method to provide water to the
pressurizer. Consequently, a backup method was provided that uses flow
into the decay heat removal suction pipe from a reactor coolant system
hot leg pipe. The licensee conducted a common mode failure evaluation
of the two methods and identified several areas where a single failure
could disable both the primary and backup BPC methods. The licensee
further, when establishing that boron precipitation will not occur in
the decay heat removal system cooler, credited flow through hot leg
nozzle gaps while not establishing that the gaps would always be
effective, and it did not include all of the specific conservatisms
required by appendix K. The licensee recognized that its changes did
not meet all aspects of the single-failure requirement and did not
include all of the specific required conservatisms. Consequently, it
requested an exemption since it believed it met the intent of the
regulations, and it justified its request on the basis of a risk
evaluation and conservatisms in calculations that result in over-
prediction of the BPC problem. The staff considers that the licensee
would also need to be exempted from the specific decay heat generation
rate contained in 10 CFR part 50, appendix K, section I.A.4. Approval
of this exemption request is needed to permit the licensee to implement
its plans to ensure BPC.

Environmental Impacts of the Proposed Action

    With regard to potential radiological impacts to the general
public, the exemption under consideration involves features located
entirely within the restricted area as defined in 10 CFR part 20. The
new active methods of BPC are an improvement when compared to the
existing methods and the entire issue of BPC has been shown to have
little effect on overall risk. The proposed action will not
significantly increase the probability or consequences of accidents, no
changes are being made in the types of any effluents that may be
released off site, and there is no significant increase in occupational
or public radiation exposure. Therefore, there are no significant
radiological environmental impacts associated with the proposed action.
    With regard to potential nonradiological impacts, the proposed
action does not involve any historic sites. It does not affect
nonradiological plant effluents and has no other environmental impact.
Therefore, there are no significant nonradiological environmental
impacts associated with the proposed actions.
    Accordingly, the NRC concludes that there are no significant
environmental impacts associated with the proposed action.

Alternatives to the Proposed Action

    As an alternative to the proposed action, the staff considered
denial of the proposed action (i.e., the ``no-action'' alternative).
Denial of the application would result in no change in current
environmental impacts. However, the licensee's exemption request covers
improvements in response to a licensee commitment to address an
existing deficiency, improvements that will decrease the risk of BPC
failure and hence decrease the risk of core damage.
    The licensee addressed further hardware improvements to reduce the
likelihood of single-failure and established there was little risk
benefit in doing so, an assessment the staff determined to be
acceptable. There is no significant benefit in this alternative.

Alternative Use of Resources

    This action does not involve the use of any resources not
previously considered in the ``Final Environmental Statement Related to
the Operation of DBNPS Unit 1,'' October 1975.

Agencies and Persons Consulted

    In accordance with its stated policy, on April 18, 2000, the staff
consulted with the Ohio State official, Carol O'Claire, of the Ohio
Emergency Management Agency, regarding the environmental impact of the
proposed action. The State official had no comments.

Finding of No Significant Impact

    On the basis of the environmental assessment, the Commission
concludes that the proposed action will not have a significant effect
on the quality of the human environment. Accordingly, the Commission
has determined not to prepare an environmental impact statement for the
proposed action.
    For further details with respect to the proposed action, see the
licensee's letters dated March 15 and April 3, 2000, which are
available for public inspection at the Commission's Public Document
Room, the Gelman Building, 2120 L Street, NW, Washington, DC. Publicly
available records are accessible electronically from the ADAMS Public
Library component on the NRC Web site, http://www.nrc.gov (the
Electronic Reading Room).

    Dated at Rockville, Maryland, this 5th day of May 2000.

    For the Nuclear Regulatory Commission.
Singh S. Bajwa,
Director, Project Directorate III, Division of Licensing Project
Management, Office of Nuclear Reactor Regulation.
[FR Doc. 00-12130 Filed 5-12-00; 8:45 am]
BILLING CODE 7590-01-P

 
 

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