[Federal Register Volume 65, Number 202 (Wednesday, October 18, 2000)]
[Notices]
[Pages 62375-62376]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-26761]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-368]
In the Matter of Entergy Operations, Inc. (Arkansas Nuclear One,
Unit 2); Exemption
I.
Entergy Operations, Inc. (Entergy, or the licensee) is the holder
of Facility Operating License No. NPF-6, which authorizes operation of
the Arkansas Nuclear One, Unit 2 (ANO-2). The license provides, among
other things,
[[Page 62376]]
that the licensee is subject to all rules, regulations, and orders of
the Commission now or hereafter in effect.
II.
Title 10 of the Code of Federal Regulations (10 CFR) part 50,
appendix J, Option B requires, in part, that licensees of all power
reactors conduct integrated leakage rate tests (ILRT) under conditions
representing design basis loss-of-coolant accident (DBLOCA) containment
peak pressure. The regulation at 10 CFR 50.12 states, in part, that in
order for the Commission to consider granting an exemption, special
circumstances must be present.
By letter dated June 29, 2000, Entergy requested that the NRC
exempt ANO-2 from the application of the specific requirements of 10
CFR part 50, appendix J, Option B. Specifically, appendix J, Option B
requires that licensees of all power reactors conduct ILRTs under
conditions representing DBLOCA containment peak pressure. The DBLOCA
containment peak pressure at ANO-2 is 58 psig, however, Entergy would
like an exemption in order to conduct the test at 68 psig. Entergy also
addresses special circumstances in its June 29, 2000, application.
III.
The ANO-2 steam generators (SGs) are scheduled for replacement
during the fall of 2000. The replacement SGs (RSGs) will require that
an access opening be cut in the containment building structure. Upon
closure of the structure, an ILRT will be required to test for primary
containment leakage integrity.
The ANO-2 containment building was originally designed and tested
for an internal pressure of 54 psig. The ANO-2 containment building has
recently been reevaluated, to address the containment post-accident
response resulting from the RSGs, for an increase in accident pressure
to 58 psig with a design pressure of 59 psig, and shown to be
acceptable as discussed in a letter to the NRC dated November 3, 1999,
as revised by a letter dated June 29, 2000. As a result of this
increase, a structural integrity test (SIT) will be performed to
evaluate the ANO-2 containment building for the change in containment
design pressure. The purpose of the SIT is to verify that the
containment building structure can safely carry design loads and that
the structural behavior is similar to that predicted by analysis. The
post-RSG SIT will be performed at 68 psig (1.15 times the revised
design pressure). The licensee desires to also perform the ILRT
concurrently with the post-RSG SIT, at the SIT pressure of 68 psig, in
order to recover approximately 30 hours of projected plant outage time.
However, Appendix J, Option B requires that the ILRT be conducted at a
pressure representing DBLOCA containment peak pressure, which is 58
psig.
Entergy cited special circumstances regarding achievement of the
underlying purpose of the regulation as part of its basis for
requesting this exemption [10 CFR 50.12(a)(2)(ii)]. Entergy noted in
support of the 10 CFR 50.12(a)(2)(ii) criteria that the application of
the current regulation is not necessary to achieve the underlying
purpose of the rule. Entergy stated that the underlying purpose of 10
CFR part 50, appendix J, Option B is still achieved in that the ILRT
will continue to measure the containment system's overall integrated
leakage rate under conditions representing DBLOCA containment peak
pressure and that leakage through the primary reactor containment will
not exceed the allowable leakage rate values as specified in the
Technical Specifications (TSs) or associated Bases. The 68-psig SIT
pressure is performed at a pressure that is greater than the DBLOCA
containment peak pressure of 58 psig. Therefore, performing the ILRT at
68 psig meets and exceeds the requirement for performing the ILRT at a
pressure representing the DBLOCA containment peak pressure (58 psig).
In addition, meeting the TS requirement for acceptable leakage at a
higher test pressure is conservative and well within the intent of
appendix J, Option B. Entergy concluded that the above information
demonstrates that there is reasonable assurance that performing the
post-RSG ILRT at the SIT test pressure of 68 psig will provide
continued validation of the leak integrity of the containment
structure.
Entergy also cited additional special circumstances as part of its
basis for requesting this exemption, namely that compliance would
result in undue costs [10 CFR 50.12(a)(2)(iii)]. Entergy stated that
the proposed exemption meets the criteria for special circumstances in
10 CFR 50.12(a)(2)(iii) in that approximately 30 hours of plant outage
time could be recovered, resulting in substantial savings. Entergy
added that since performance of the ILRT at the SIT pressure is
conservative, they believe that realizing this benefit is acceptable.
IV.
The NRC staff has reviewed the licensee's application. Regarding
assurance of safe operation, the staff finds that since the use of the
higher SIT pressure is conservative and since the licensee will be
following the applicable regulations and guidance for performing the
ILRT, the use of the SIT pressure for the ILRT is technically
acceptable. Regarding compliance with 10 CFR 50.12(a)(2)(ii), the staff
finds that since the licensee will still perform an ILRT, and it will
be performed at a pressure which is conservative with respect to that
required by 10 CFR part 50, Appendix J, Option B, the underlying
purpose of the rule, to ensure an essentially leak tight containment,
is satisfied and this special circumstance applies. Regarding
compliance with 10 CFR 50.12(a)(2)(iii), the staff disagrees that this
special circumstance applies. Since ANSI/ANS 56.8-1994 (section 5.4)
recognizes the situation in which an ILRT is performed after an SIT,
this situation cannot be considered as an undue hardship or a burden
significantly in excess of that which might be incurred by other
licensees in similar circumstances. The staff's detailed Safety
Evaluation (and this exemption) are enclosures in the letter to the
licensee dated
V.
The Commission has determined that, pursuant to 10 CFR 50.12, this
exemption is authorized by law, will not present an undue risk to the
public health and safety, is consistent with the common defense and
security, and is otherwise in the public interest. Therefore, the
Commission hereby grants Entergy Operations, Inc. a one-time exemption
from the requirements of 10 CFR part 50, appendix J, Option B in order
to provide a one-time allowance to conduct the containment ILRT at the
same pressure that is used for the SIT.
Pursuant to 10 CFR 51.32, the Commission has determined that the
granting of this exemption will have no significant effect on the
quality of the human environment (65 FR 59216, dated October 4, 2000).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 12th October, 2000.
For the Nuclear Regulatory Commission
John A. Zwolinski,
Director, Division of Licensing Project Management, Office of Nuclear
Reactor Regulation.
[FR Doc. 00-26761 Filed 10-17-00; 8:45 am]
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