[Federal Register Volume 60, Number 25 (Tuesday, February 7, 1995)]
[Notices]
[Pages 7226-7227]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-2956]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-352 and 50-353]
Philadelphia Electric Company; Limerick Generating Station, Units
1 and 2; Environmental Assessment and Finding of No Significant Impact
The U.S. Nuclear Regulatory Commission (the Commission) is
considering two actions: (1) Issuance of an exemption from the
requirements of 10 CFR 50, Appendix J, and (2) an amendment to Facility
Operating License Nos. NPF-39 and NPF-85, issued to Philadelphia
Electric Company (the licensee), for operation of the Limerick
Generating Station (LGS), Units 1 and 2, located in Montgomery County,
Pennsylvania.
Environmental Assessment
Identification of the Proposed Action
The proposed action would grant (1) an exemption from 10 CFR Part
50, Appendix J, Sections II.H.4, III.C.2, and III.C.3, and (2) an
amendment to change the Technical Specifications (TS) for the Limerick
Generating Station (LGS), Units 1 and 2, in conjunction with the
removal of the main steam isolation valve (MSIV) leakage control system
(LCS) and the proposed use of an alternate leakage pathway.
10 CFR Part 50, Appendix J, Sections II.H.4 and III.C.2 require
leak rate testing of MSIVs at the calculated peak containment pressure
related to the design basis accident, and Section III.C.3 requires that
the measured MSIV leak rates be included in the combined local leak
rate test results. The proposed deletion of the MSIV LCS and proposed
use of an alternate leakage pathway affects the description of an
existing exemption (NUREG-0991, and its Supplement 3), which allows the
leak rate testing of the MSIVs at a reduced pressure and allows
exclusion of the measured MSIV leakage from the combined local leak
rate test results.
The proposed TS amendment would permit an increase in the allowable
MSIV leakage rate from 11.5 standard cubic feet per hour (scfh) to 100
scfh for any one MSIV and a combined maximum pathway leakage rate of
200 scfh for all four main steam lines, and would delete TS
requirements for the currently installed MSIV LSC, because the proposed
system removal makes the TS inapplicable.
The proposed action for the TS amendments is in accordance with the
licensee's application for amendment dated January 14, 1994, as
supplemented by letters dated August 1, October 25, December 13, and
December 22, 1994; and the proposed action for the exemption is in
accordance with the letter dated December 22, 1994.
The Need for the Proposed Action
The proposed exemption is similar to the current exemption from 10
CFR Part 50, Appendix J, Sections II.H.4 and III.C.2. The exemption is
needed since the design of the MSIVs is such that testing in the
reverse direction tends to unseat the value and would result in a
meaningless test. The total observed MSIV leak rate resulting from a
leakage test where two MSIVs on one steam line are tested utilizing a
reduced pressure (22 psig) will continue to be assigned to the
penetration. The proposed exemption is also similar to the current
exemption from 10 CFR Part 50, Appendix J, Section III.C.3. The
licensee proposes that the MSIV leakage rate will continue to be
accounted for separately in the radiological site analysis in
accordance with the existing exemption. However, the existing exemption
from 10 CFR Part 50, Appendix J, Section III.C.3 will not be applicable
when the MSIV LCS is replaced with an Alternate Treatment Path (ATP)
(main steam lines and condenser).
The proposed action regarding the TS amendment will reduce the need
for repairs of the MSIVs, resolve concerns associated with the current
LCS performance capability at high MSIV leakage rates, and provide an
effective method for dealing with a potential MSIV leakage during a
postulated loss-of-coolant accident (LOCA). Many boiling water reactors
(BWRs) have difficulty meeting their MSIV leakage rate limits.
Extensive repair, rework, and retesting efforts have negative effects
on the outage costs and schedules, as well as significant impact on the
licensee's as low as is reasonably achievable (ALARA) radiological
exposure programs. The alternatives proposed by the licensee to deal
with MSIV leakage make use of components (main steam lines and
condenser) that are expected to remain intact and serviceable following
a design basis LOCA.
Enviroinmental Impacts of the Proposed Action
The Commission has completed its evaluation of the proposed actions
related to the granting of an exemption [[Page 7227]] from 10 CFR Part
50, Appendix J, Section 11.H.4, III.C.2, and III.C.3, and for the TS
changes proposed by the licensee, and concludes that the proposed
actions will not increase the probability or consequences of accidents,
no changes are being made in the types of any effluents that may be
released offsite, and there is no significant increase in the allowable
individual or cumulative occupational radiation exposure.
Regarding the exemption, the MSIV leakage, along with the
containment leakage is used to calculate the maximum radiological
consequences of a design basis accident. Section 15.6.5 of the LGS
Updated Final Safety Analysis Report (UFSAR) identifies that standard
and conservative assumptions have been used to calculate the offsite
and control room doses, including the doses due to MSIV leakage, which
could potentially result from a postulated LOCA. Further, the control
room and offsite doses resulting from a postulated LOCA have recently
been recalculated using currently accepted assumptions and methods.
These analyses have demonstrated that the total leakage rate of 200
scfh results in dose exposures for the control room and offsite that
remain within the requirements of 10 CFR Part 100 for offsite doses and
10 CFR Part 50, Appendix A, for the control room doses.
Regarding the TS change, deletion of the MSIV LCS will reduce the
overall occupational dose exposures and reduce the generation of low
level radioactive waste due to the elimination of maintenance and
surveillance activities associated with the system. The dose exposure
associated with deleting the system will satisfy the ALARA
requirements, and will be less than the dose which would result from
maintenance and surveillance activities associated with the present
system, if utilized for the remainder of the plant life. Thus,
radiological releases will not differ significantly from those
determined previously, and the proposed amendment does not otherwise
affect facility radiological effluent or occupational exposures.
Therefore, there will not be a significant increase in the types
and amounts of any effluent that may be released offsite and, as such,
the proposed amendment does not alter any initial conditions assumed
for the design basis accidents previously evaluated and the alternate
system is capable of mitigating the design basis accidents.
Furthermore, the proposed exemption will not result in a
significant increase to the LOCA doses previously evaluated against
offsite and main control room dose limits contained in 10 CFR Part 100
and 10 CFR Part 50, Appendix A, General Design Criteria 19.
With regard to potential nonradiological impacts, the proposed
actions involve features located entirely within the restricted area as
defined in 10 CFR Part 20. They do not affect nonradiological plant
effluents and have no other environmental impact. Accordingly, the
Commission concludes that there are no significant nonradiological
environmental impacts associated with the proposed actions.
Alternatives to the Proposed Action
Since the Commission has concluded there is no measurable
environmental impact associated with the proposed actions, any
alternatives with equal or greater environmental impact need not be
evaluated. As an alternative to the proposed actions, the staff
considered denial of the proposed actions. Denial of the application
would result in no change in current environmental impacts. The
environmental impacts of the proposed action and the alternative action
are similar.
Alternative Use of Resources
This action does not involve the use of any resources not
previously considered in the Final Environmental Statement for the LGS,
Units 1 and 2.
Agencies and Persons Consulted
In accordance with its stated policy, the staff consulted with the
Pennsylvania State official regarding the environmental impact of the
proposed actions. The State official had no comments.
Finding of No Significant Impact
Based upon the environmental assessment, the Commission concludes
that the proposed actions 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 actions.
For further details with respect to the proposed actions, see the
licensee's letter dated January 14, 1994, as supplemented by letters
dated August 1, October 25, December 13, and December 22, 1994 (two
submittals), which are available for public inspection at the
Commission's Public Document Room, The Gelman Building, 2120 L Street,
NW., Washington, DC, and at the local public document room located at
the Pottstown Public Library, 500 High Street, Pottstown, PA 19464.
Dated at Rockville, Maryland, this 1st day of February 1995.
For the Nuclear Regulatory Commission.
Frank Rinaldi,
Acting Director, Project Directorate I-2, Division of Reactor
Projects--I/II, Office of Nuclear Reactor Regulations.
[FR Doc. 95-2956 Filed 2-6-95; 8:45 am]
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