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In the Matter of Entergy Operations, Inc. (Arkansas Nuclear One, Unit 2); Exemption

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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, Start Printed Page 62376that the licensee is subject to all rules, regulations, and orders of the Commission now or hereafter in effect.


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.


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.


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


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.

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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.

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[FR Doc. 00-26761 Filed 10-17-00; 8:45 am]