[Federal Register Volume 59, Number 247 (Tuesday, December 27, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-31779]


[[Page Unknown]]

[Federal Register: December 27, 1994]


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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-220]

 

Niagara Mohawk Power Corporation; (Nine Mile Point Nuclear 
Station Unit No. 1); Exemption

I

    Niagara Mohawk Power Corporation (NMPC or the licensee) is the 
holder of Facility Operating License No. DPR-63, which authorizes 
operation of Nine Mile Point Nuclear Station Unit No. 1 (the facility 
or NMP1), at a steady-state reactor power level not in excess of 1850 
megawatts thermal. The facility is a boiling water reactor located at 
the licensee's site in Oswego County, New York. The license provides 
among other things, that it is subject to all rules, regulations, and 
Orders of the U.S. Nuclear Regulatory Commission (the Commission or 
NRC) now or hereafter in effect.

II

    Section III.D.1.(a) of Appendix J to 10 CFR Part 50 requires the 
performance of three Type A containment leakage rate tests, at 
approximately equal intervals during each 10-year service period of the 
primary containment. The third test of each set shall be conducted when 
the plant is shutdown for the 10-year inservice inspection of the 
primary containment.

III

    By letter dated August 26, 1994, NMPC requested temporary relief 
from the requirement to perform a set of three Type A tests at 
approximately equal intervals during each 10-year service period of the 
primary containment. The requested exemption would permit a one-time 
extension of the second 10-year service period of approximately 24 
months (from the 1995 refueling outage, currently scheduled to begin in 
February 1995, to the 1997 refueling outage). The requested temporary 
relief would permit the third test of the containment's second 10-year 
inservice inspection period to correspond with the end of the current 
American Society of Mechanical Engineers Boiler and Pressure Vessel 
Code (ASME Code) inservice inspection interval.

IV

    Section III.D.1.(a) of Appendix J to 10 CFR Part 50 states that a 
set of three Type A leakage rate tests shall be performed at 
approximately equal intervals during each 10-year service period.
    The requirement to perform a set of three Type A leakage rate tests 
at approximately equal intervals during each 10-year containment 
service period provides assurance that the containment is leak tight. 
Type A leakage rate tests were performed as required by Appendix J 
during the first 10-year containment service period (1974-1984). The 
second 10-year containment service period is scheduled to end in 
December 1994.
    Due to a lengthy outage for the replacement of reactor 
recirculation piping, the first ASME Code required Inservice Inspection 
(ISI) 10-year interval was extended to June 1986. An extended refueling 
outage (January 1987 to July 1990) resulted in the second 10-year ISI 
interval being extended to December 1998. These extensions were made in 
accordance with the provisions of Section XI of the ASME Code and have 
resulted in the ISI intervals being decoupled from the Type A leakage 
test intervals since Appendix J does not contain any provisions for 
adjusting the 10-year intervals as does the ASME Code for extended 
outages.
    Two Type A tests have already been performed (May 1990 and April 
1993) during the second 10-year containment service interval. Since 
this second interval is scheduled to end in December 1994, the third 
test would be required during the next refueling outage (February 
1995). However, in an attempt to recouple the schedule for the Type A 
tests with the ISI schedule and to avoid performing an additional Type 
A test, the license has proposed to extend the third Type A test of the 
second interval until the 1997 refueling outage and to perform the 
final tests of the second ISI interval at that time. This action would 
eliminate the need to perform an extra Type A test which could 
otherwise be required (one test in 1995 and another in 1997) while 
recoupling the Type A test schedule with the ISI schedule.

V

    The Commission has determined that pursuant to 10 CFR 50.12(a)(1) 
this exemption is authorized by law, will not present an undue risk to 
the public health and safety, and is consistent with the common defense 
and security. The Commission further determines that special 
circumstances, as provided in 10 CFR 50.12(a)(2)(ii), are present 
justifying the exemption; namely, that application of the regulation in 
the particular circumstances is not necessary to achieve the underlying 
purpose of the rule. The underlying purpose of Section III.D.1.(a) of 
the Appendix J to 10 CFR Part 50 is to provide an interval short enough 
to prevent serious deterioration from occurring between tests and long 
enough to permit testing to be performed during regular plant outages.
    The last Type A test was performed in April 1993. Performance of 
another Type A test in February 1995 would result in a test interval of 
only 22 months. Whereas if the 10-year interval was equally divided 
into three intervals, each test interval would be 40 months. Delaying 
the next Type A test until the 1997 refueling outage would result in a 
test interval of approximately 46 months since NMP1 is currently 
operating on a 24-month fuel cycle. The 46-month test interval would be 
consistent with the NRC staff's current position (as reflected in the 
NRC's Standard Technical Specifications) that Type A test intervals 
should be 40  10 months. Furthermore, the licensee has 
presented the following information which gives a high degree of 
confidence that the containment will not degrade to an unacceptable 
extent while this exemption is in effect:
    1. The two most recent Type A test data show that the ``as left'' 
leakage rates (0.463% wt/day and 0.4634% wt/day, respectively) were 
well within the acceptance limit of 0.75 Lt (0.892% wt/day).
    2. There have been no permanent or temporary modifications to the 
containment structure, liner, or penetrations since the last Type A 
test that could adversely affect the Type A test results.
    3. No modifications that require a Type A test are planned prior to 
the 1997 refueling outage.
    4. There have been no pressure or temperature excursions in the 
containment which could have adversely affected containment integrity.
    Pursuant to 10 CFR 51.32, the Commission has determined that 
granting this Exemption will not have a significant impact on the 
environment (59 FR 62752).
    This Exemption is effective upon issuance and shall expire at the 
completion of the 1997 refueling outage.

    For the Nuclear Regulatory Commission.

    Dated at Rockville, Maryland, this 20th day of December 1994.
Steven A. Varga,
Director, Division of Reactor Projects--I/II, Office of Nuclear Reactor 
Regulation.
[FR Doc. 94-31779 Filed 12-23-94; 8:45 am]
BILLING CODE 7590-01-M