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Exelon Generation Company, LLC; Dresden Nuclear Power Station, Units 2 and 3 Exemption

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1.0 Background

The Exelon Generation Company, LLC, (Exelon, or the licensee) is the holder of Facility Operating License Nos. DPR-19 and DPR-25, which authorizes operation of the Dresden Nuclear Power Station (DNPS), Units 2 and 3, respectively. The licenses provide, among other things, that the facilities are subject to all rules, regulations, and orders of the U.S. Nuclear Regulatory Commission (NRC, the Commission) now or hereafter in effect.

The facility consists of two boiling water reactors located in Grundy County, Illinois.

2.0 Request/Action

Title 10 of the Code of Federal Regulations (10 CFR) part 50, section 50.55a(g)(6)(ii)(A)(2) incorporates American Society of Mechanical Engineers (ASME) Code, Section XI, Table IWB-2500-1. Item B1.12 of ASME code, Section XI, Table IWB-2500-1 requires that all longitudinal reactor pressure vessel (RPV) shell welds be inspected during each ten-year inspection interval. Additionally, item B1.30 requires that the shell-to-flange weld be inspected during each inspection interval.

In its submittal dated June 12, 2001, as supplemented by a letter dated July 23, 2001, the licensee requested an exemption from the ASME Code, Section XI requirements, items B1.12 and B1.30 of Table IWB-2500-1. The licensee requested a one cycle extension of the requirement to inspect the RPV welds for the Dresden Units 2 and 3 per the provisions of 10 CFR 50.55a(a)(3)(ii). Specifically, the licensee concluded that compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

Until recently, the licensee intended to use standard inspection techniques on RPV welds during the upcoming (17th) refueling outages for both units. The outages are scheduled for October 2001 and September 2002 for Units 2 and 3, respectively. Using standard equipment, the licensee projects that they would be able to inspect approximately 60 percent of the length of vertical welds.

In order to improve and increase their capability to perform RPV weld examinations, the licensee proposes to implement the AIRIS 21 system. The AIRIS 21 system is a nondestructive examination (NDE) tool developed by IHI Southwest Technologies (ISWT). The licensee proposes to have ISWT install the new system and inspect vertical welds along the lower beltline course as well as the shell-to-flange weld during the 17th refueling outage for both units. Coverage of the lower beltline course is not obtainable using standard inspection techniques. Using the AIRIS 21 system, the licensee anticipates examining 14 of the 18 vertical welds as well as the shell-to-flange weld during the upcoming 17th refueling outage for both units. Approximately 90 percent of the shell-to-flange weld is expected to be examined while 50 to 100 percent of the vertical welds are expected to be examined. The licensee expects to complete examinations for the remaining four vertical welds using the AIRIS 21 system in the 18th refueling outage for both units.

The AIRIS 21 device will require additional refueling bridge support. Therefore, in order to inspect all of the welds required by the ASME Code during the 17th refueling outages, outage time would be increased by 64 hours according to the licensee's estimates. The licensee concludes that this considerable extension in outage time presents undue hardship.

3.0 Discussion

Pursuant to 10 CFR 50.12, the Commission may, upon application by any interested person or upon its own initiative, grant exemptions from the requirements of 10 CFR part 50, when (1) the exemptions are authorized by law, will not present an undue risk to public health or safety, and are consistent with the common defense and security; and (2) when special circumstances are present. According to 10 CFR 50.12(a)(2)(iii), special circumstances are present whenever compliance would result in undue hardship or other costs that are significantly in excess of those contemplated when the regulation was adopted. The requested schedular exemption is required to prevent an extended shutdown of the facility for the purpose of conducting RPV inservice examinations. In addition, according to 10 CFR 50.12(a)(2)(v), special circumstances are also present whenever the exemption would provide only temporary relief from the applicable regulation. The requested exemption is only needed for eight months for Unit 2 and 24 months for Unit 3 to achieve increased inspection coverage without an outage schedule impact.

As described in the staff's safety evaluation dated September 28, 2001, the staff finds that the deferral of the examinations of RPV welds for one cycle will not present undue risk to the public and the AIRIS 21 system is expected to result in a more complete inspection during future outages. The safety evaluation may be examined, and/or copied for a fee, at the NRC's Public Document Room, located at One White Flint North, 11555 Rockville Pike (first floor), Rockville, Maryland. Publicly available records will be accessible electronically from the ADAMS Public Library component on the NRC Web site, (the Electronic Reading Room).

4.0 Conclusion

Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12(a), the exemption is authorized by law, will not endanger life or property or common defense and security, and is, otherwise, in the public interest. Also, special circumstances are present. Therefore, the Commission hereby grants Exelon an exemption from the requirements of 10 CFR 50.55a(g)(6)(ii)(A)(2) for Dresden Nuclear Power Station, Units 2 and 3.

Pursuant to 10 CFR 51.32, the Commission has determined that the granting of this exemption will not have a significant effect on the quality of the human environment (66 FR 49713).

This exemption is effective upon issuance.

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Dated at Rockville, Maryland, this 28th day of September 2001.

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. 01-24999 Filed 10-4-01; 8:45 am]