ML101870610
| ML101870610 | |
| Person / Time | |
|---|---|
| Issue date: | 09/30/2010 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| Orr, Mark 301-251-7495 | |
| Shared Package | |
| ML100840566 | List: |
| References | |
| DG-1244 RG-1.093, Rev 1 | |
| Download: ML101870610 (2) | |
Text
Page 1 REGULATORY ANALYSIS DRAFT REGULATORY GUIDE DG-1244 AVAILABILITY OF ELECTRIC POWER SOURCES (Proposed Revision 1 to Regulatory Guide 1.93, dated December 1974)
Statement of the Problem the U.S. Nuclear Regulatory Commission (NRC) published Regulatory Guide 1.93 in December 1974 to provide licensees with agency-approved guidance for complying with the regulations for the availability of electric power sources in the then current version of Title 10, Part 50 of the Code of Federal Regulations (10 CFR Part 50). The implementation of a risk-informed and performance-based approach and the multiple revisions and additions to 10 CFR Part 50 make the current regulatory guide obsolete.
The NRC issued earlier draft guides (i.e., DG-1153 and DG-1195) in October 2006 and September 2008, respectively, but later withdrew them to resolve multiple comments. The NRC has made major modifications to these earlier draft guides to address the comments and concerns and is issuing this new draft guide to promulgate its viewpoint. Therefore, revision of this regulatory guidance is necessary to provide licensees with more modern guidance that incorporates the risk-informed and performance-based approach currently favored by the NRC.
Objective The objective of this regulatory action is to provide a more useful and up-to-date version of the guidance that the NRC considers acceptable when available electric power sources are less than the number of sources required by the limiting conditions for operations (LCOs) for the facility.
Alternative Approaches The NRC staff considered the following alternative approaches:
Do not revise Regulatory Guide 1.93.
Revise Regulatory Guide 1.93.
Alternative 1: Do Not Revise Regulatory Guide 1.93 Under this alternative, the NRC would not revise this guidance, and the current guidance would be retained. If the NRC does not take action, there would not be any changes in costs or benefit to the public, licensees, or the NRC. However, the no-action alternative would not address identified concerns with the current version of the regulatory guide. The NRC would continue to review each application on a case-by-case basis. This alternative provides a baseline condition from which any other alternatives will be assessed.
Alternative 2: Revise Regulatory Guide 1.93 Under this alternative, the NRC would revise Regulatory Guide 1.93, taking into consideration the need to address current regulations and to prepare for multiple new license applications. This action would address an important aspect of safe NPP operation in the event of a loss of onsite and offsite power sources that result in a failure to meet the LCOs. This revised regulatory guide will replace old, outdated,
Page 2 and inapplicable guidance with updated guidance that focuses on a regulatory framework that has changed since the NRC first issued Regulatory Guide 1.93.
The impact to the NRC would be the costs associated with preparing and issuing the regulatory guide revision. The impact to the public would be the voluntary costs associated with reviewing and providing comments to the NRC during the public comment period. The value to the NRC staff and its applicants would be the benefits associated with enhanced efficiency and effectiveness in using a common guidance document as the technical basis for license applications and other interactions between the NRC and its regulated entities.
Conclusion Based on this regulatory analysis, the NRC staff recommends revision of Regulatory Guide 1.93.
The staff concludes that the proposed action will enhance reactor safety by providing a more risk-informed and performance-based approach to the loss of onsite and offsite electrical power sources that result in a failure to meet the LCO. It could also lead to cost savings for the industry, especially with regard to applications for standard plant design certifications and combined licenses.