[Federal Register Volume 60, Number 13 (Friday, January 20, 1995)]
[Notices]
[Pages 4202-4203]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-1474]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-237]
Commonwealth Edison Company; (Dresden Nuclear Power Station, Unit
2); Exemption
I
Commonwealth Edison Company (ComEd, the licensee) is the holder of
Facility Operating License No. DPR-19, which authorizes operation of
the Dresden Nuclear Power Station, Unit 2 (the facility), at a steady-
state power level not in excess of 2527 megawatts thermal. The facility
is a boiling water reactor located at the licensee's site in Grundy
County, Illinois. This license provides, among other things, that the
facility is subject to all rules, regulations, and Orders of the U.S.
Nuclear Regulatory Commission (the Commission) now or hereafter in
effect.
II
By letter dated November 23, 1994, pursuant to 10 CFR 50.12(a),
ComEd requested a schedular exemption for Dresden, Unit 2, from the 24-
month test interval for the Type B and C local leak rate test (LLRT) as
required by 10 CFR Part 50, Appendix J, Sections III.D.2(a) and
III.D.3. The exemption is requested to avoid a potential reactor shut
down to perform the Type B and C tests.
Due to two forced outages, ComEd has had to reschedule the Dresden,
Unit 2, refueling outage from February 1995 to July 1995. Subsequently,
ComEd requested a maximum extension of up to an additional 180 days for
the most extreme case, from performing the Type B and C testing. The
Type B and C tests cannot be performed during power operation.
III
In its letter dated November 23, 1994, ComEd requested a one-time
exemption from the 24-month Type B and C test interval requirements of
Appendix J for certain volumes (i.e., bellows, manway gasket seals,
flanges, and isolation valves) identified in Attachment III of the
licensee's submittal. ComEd stated that these volumes cannot be tested
while the reactor is at power and provided the basis for this
conclusion in Attachment IV of their submittal.
The licensee provided leakage test results and maintenance
information on these volumes for the past two refueling outages. The
current maximum pathway leakage rate for Dresden, Unit 2, as determined
through Type B and C leak rate testing, is 309.46 standard cubic feet
per hour (scfh). This value is approximately 63 percent of the
Technical Specification (TS) limit of 488.45 scfh (o.6La). In
addition, the previous outage ``as left'' total minimum pathway leakage
rate for Type B and C testable penetrations was 173.25 scfh.
The Type A integrated leak rate test, which obtains the summation
of all potential leakage paths (including containment welds, valves,
fittings, and penetrations) was performed on May 14, 1993. The
resulting leakage from the test was 493.36 scfh. This value is
approximately 80.8 percent of the limit specified in the TS (o.75
La).
In order to provide an added margin of safety and to account for
possible increases in the leakage rates of untested volumes during the
relatively short period of the exemption, Dresden Nuclear Power
Station, United 2, will impose an administrative limit for maximum
pathway leakage of 80 percent of 0.6La for the remaining Unit 2
fuel cycle.
To reduce the number of volumes which need an exemption, ComEd will
test the volumes listed in Attachment V of their submittal during
reactor operation. In addition, volumes listed in Attachment III of
their submittal will be tested should a forced outage of suitable
duration occur prior to July 16, 1995.
The staff has reviewed ComEd's submittal regarding the Appendix J
test interval exemption request. In summary, the staff finds that, for
the specific volumes listed in Attachment III of ComEd's submittal,
extending the schedule for the required Type B and C tests by 180 days
will not affect containment integrity based on the following:
1. Testing has shown low ``as found'' leakage during the past two
outages. The ample margin between the measured leakage and the
allowable leakage should accommodate any degradation likely to be
experienced for these components during the extended period.
2. The intent of Appendix J was that Type B and C testing be
performed during a refueling outage. It is not the intent of Appendix J
to require a shutdown solely for surveillance testing. The exemption
would provide relief from the requirements of Appendix J to allow a
test interval extension for these components which only became
necessary as a result of rescheduling the Unit 2, Cycle 14, refueling
outage .
Based on the above discussion, the staff finds that for the
component volumes identified in Attachment III of ComEd's submittal, an
exemption from the LLRT test frequency specified in Appendix J should
be granted.
IV
Based on the above, the staff concludes that the licensee's
proposed extension of the test intervals for test components identified
in its submittal is acceptable. This is a one-time exemption from the
Type B and C test interval requirements as prescribed in Appendix J,
and is intended to be in effect until July 16, 1995. This approval is
based on the assumption that all other tests will be conducted in
accordance with the requirements of Appendix J.
The Commission's regulations at 10 CFR 50.12 provide that special
circumstances must be present in order for an exemption from the
regulations to be granted. According to 10 CFR 50.12(a)(2)(ii), special
circumstances are present whenever application of the regulation in the
particular circumstances would not serve the underlying purpose of the
rule or is not necessary to achieve the underlying purpose of the rule.
The underlying purpose of the requirement to perform Type B and Type C
containment leak rate tests at intervals not to exceed 2 years, is to
ensure that any potential leakage pathways through the containment
boundary are identified within a time span that prevents significant
degradation from continuing [[Page 4203]] or being unknown, and long
enough to allow the tests to be conducted during scheduled refueling
outages. This interval was originally published in Appendix J when
refueling cycles were conducted at approximately annual intervals and
has not been changed to reflect 18-month or 2-year operating cycles. It
is not the intent of the regulation to require a plant shutdown solely
for the purpose of conducting the periodic leak rate tests. As
indicated above, based on past local leakage rate testing data, the
180-day extension of the test interval will not affect the performance
of the containment. To require a shutdown solely for surveillance
testing would not serve the underlying purpose of the rule.
Accordingly, the Commission has determined, pursuant to 10 CFR
50.12(a), that this exemption is authorized by law and will not present
an undue risk to the public health and safety, and is consistent with
the common defense and security. In addition, the Commission has found
special circumstances in that application of the regulation in these
particular circumstances would not serve the underlying purpose of the
rule. Therefore, the Commission hereby grants the exemption from 10 CFR
Part 50, Appendix J, Sections III.D.2(a) and III.D.3 to the extent that
the Appendix J test interval for performing Type B tests (except for
air locks) and Type C tests may be extended for 180 days until July 16,
1995, on a one-time only basis, for Dresden, Unit 2, as described in
Section III above.
Pursuant to 10 CFR 51.32, the Commission has determined that the
granting of this Exemption will have no significant impact on the
quality of the human environment (60 FR 3277).
Dated at Rockville, Maryland this 13th day of January 1995.
For the Nuclear Regulatory Commission.
Jack W. Roe,
Director, Division of Reactor Projects--III/IV, Office of Nuclear
Reactor Regulation.
[FR Doc. 95-1474 Filed 1-19-95; 8:45 am]
BILLING CODE 7590-01-M
