Exelon Generation Company, LLC; Limerick Generating Station, Unit Nos. 1 and 2; Exemption

1.0 Background

Exelon Generation Company, LLC, (the licensee) is the holder of Facility Operating License Nos. NPF-39 and NPF-85 which authorize operation of the Limerick Generating Station (LGS), Unit Nos. 1 and 2. The license provides, among other things, that the facility is 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 dual unit boiling water reactors located in Montgomery County in Pennsylvania.

2.0 Request/Action

Title 10 of the Code of Federal Regulations (10 CFR), Section 50.71 “Maintenance of records, making of reports,” paragraph (e)(4) states, in part, that “Subsequent revisions [to the Updated Final Safety Analysis Report (UFSAR)] must be filed annually or 6 months after each refueling outage provided the interval between successive updates [to the UFSAR] does not exceed 24 months.” The two units at LGS share a common UFSAR, therefore, this rule requires the licensee to update the same document annually or within 6 months after each unit's refueling outage. Since each unit is on a staggered 24 month refueling cycle, updating after each refueling outage also results in an annual update. Single unit sites using a 24 month refueling cycle would only be required to update the UFSAR on a 24 month periodicity. The proposed exemption would allow updates to the combined UFSAR for LGS, Unit Nos. 1 and 2, to be submitted within 6 months following completion of each LGS Unit 1 refueling outage, not to exceed 24 months from the previous submittal.

In summary, the licensee has requested an exemption that would allow updates to the LGS UFSAR at a periodicity not to exceed 24 months, similar to the periodicity permitted for single unit sites.

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. The last change to 10 CFR 50.71(e)(4) was published in the Federal Register (57 FR 39358) on August 31, 1992, and became effective on October 1, 1992. The underlying purpose of the rule change was to relieve licensees of the burden of filing annual UFSAR revisions, especially if there had been no refueling outages since the previous revision. Most of the changes which lead to revision of the UFSAR occur during refueling outages. The revised 10 CFR 50.71(e)(4) also assured that such revisions are made at least every 24 months. However, as written, the burden reduction can only be realized by single-unit facilities, or multiple-unit facilities that maintain separate UFSARs for each unit. In the Summary and Analysis of Public Comments accompanying the 10 CFR 50.71(e)(4) rule change published in the Federal Register (57 FR 39355, 1992), the NRC acknowledged that the final rule did not provide burden reduction to multiple-unit facilities sharing a common UFSAR. The NRC stated: “With respect to the concern about multiple facilities sharing a common FSAR, licensees will have maximum flexibility for scheduling updates on a case-by-case basis.” Granting this exemption would provide burden reduction to LGS while still assuring that revisions to the LGS UFSAR are made at least every 24 months.

The NRC staff examined the licensee's rationale to support the exemption request and concluded that updating the LGS UFSAR within 6 months following completion of each LGS Unit 1 refueling outage, not to exceed 24 months from the previous submittal, meets the underlying purpose of 10 CFR 50.71(e)(4), since the LGS UFSAR would be updated at least every 24 months, similar to the UFSAR at a single unit site. The requirement to revise the UFSAR annually or within 6 months after the refueling outages for each unit, therefore, is not necessary to achieve the underlying purpose of the rule. In addition, the NRC previously acknowledged that the revision to 10 CFR 50.71(e)(4) did not directly address burden reduction for multiple-unit facilities that share a common UFSAR, but that such situations could be addressed on a case-by-case basis. The NRC staff has reviewed the licensee's request and has concluded that application of the regulation in these circumstances is not necessary to achieve the underlying purpose of the rule.

Therefore, the NRC staff concludes that pursuant to 10 CFR 50.12(a)(2)(ii) special circumstances are present.

In addition, the Commission has determined that, pursuant to 10 CFR 50.12(a), the 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.

4.0 Conclusion

Accordingly, the Commission hereby grants the licensee an exemption from the requirements of 10 CFR 50.71(e)(4) for LGS Unit Nos. 1 and 2, in that updates to the combined UFSAR for LGS, Unit Nos. 1 and 2, may be submitted within 6 months following completion of each LGS Unit 1 refueling outage, not to exceed 24 months from the previous submittal.

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 40300).

This exemption is effective upon issuance.