SUPPLEMENTARY INFORMATION:

I. Background

Following the events at the Fukushima Dai-ichi nuclear power plant on March 11, 2011, the NRC established a senior-level agency task force referred to as the Near-Term Task Force (NTTF). The NTTF was tasked with conducting a systematic and methodical review of the NRC regulations and processes, and determining if the agency should make additional improvements to these programs in light of the events at Fukushima Dai-ichi. As a result of this review, the NTTF developed a comprehensive set of recommendations, documented in SECY-11-0093, “Recommendations for Enhancing Reactor Safety in the 21st Century, the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident,” dated July 12, 2011. These recommendations were enhanced by the NRC staff following interactions with stakeholders. Documentation of the staff's efforts is contained in SECY-11-0124, dated September 9, 2011, and SECY-11-0137, dated October 3, 2011.

As directed by the Commission's SRM for SECY-11-0093, the NRC staff reviewed the NTTF recommendations within the context of the NRC's existing regulatory framework and considered the various regulatory vehicles available to the NRC to implement the recommendations. In SECY-11-0124 and SECY-11-0137, the staff established the prioritization of the recommendations. After receiving the Commission's direction in SRM-SECY-11-0124 and SRM-SECY-11-0137, the NRC staff issued a request for information pursuant to section 50.54(f) of title 10 of the Code of Federal Regulations (10 CFR), “Conditions of licenses,” on March 12, 2012, requesting licensees to reevaluate the seismic and flooding hazards at their sites using updated hazard information and current regulatory guidance and methodologies. For plants where the reevaluated hazard exceeds the plant's design basis, the licensee was to conduct an integrated assessment. The information gathering is considered to be Phase 1 and was requested to support Phase 2 decision-making and determine whether available or planned measures provide sufficient protection and mitigation capabilities or if further regulatory action should be pursued in the areas of seismic and flooding design, and emergency preparedness.

In COMSECY-14-0037, dated November 21, 2014, the NRC staff requested that the Commission review and approve changes to revise the Recommendation 2.1 flooding assessments and integrate the Phase 2 decision-making into the development and implementation of mitigating strategies in accordance with Order EA-12-049 and the related Mitigation of Beyond-Design-Basis Events rulemaking.

In SRM-COMSECY-14-0037, the Commission disapproved this recommendation. Instead, the Commission instructed the staff to develop a closure plan for the flooding reevaluation activities and to reassess the existing guidance for performing a Phase 1 integrated assessment in order to focus on those plants with the most potential for safety benefits.

In COMSECY-15-0019, the staff provided revised guidance for performing a Phase 1 integrated assessment and described a modified process for identifying the list of plants that would be required to perform an integrated assessment. The process proposed by the staff included the development of a graded, risk-informed and performance-based approach consistent with Commission direction to focus on those plants with the greatest potential opportunity for safety enhancements. Specifically, the process included consideration and evaluation of local intense precipitation by performing a focused evaluation of the impact of the hazard and implementing any necessary programmatic, procedural, or plant modifications to address the hazard, taking into account available warning time. The process also considered flood protection and available physical margin, where licensees will confirm the capability of existing flood protection to address the hazard exceedance by performing a focused evaluation. For licensees where the reevaluated hazard cannot be addressed via existing or planned flood protection, the process also includes the performance of an integrated assessment, using revised guidance, in order to conduct more detailed evaluations of plant response capability. This revised integrated assessment will capture, among other information, quantitative characteristics about the effectiveness of various aspects of plant response ( e.g., reliability of equipment and feasibility of manual actions), and risk insights with a focus on cliff-edge effects. The results will be used by the NRC to determine whether additional regulatory action, such as a plant- specific backfit, are warranted.

In SRM-COMSECY-15-0019, the Commission approved the staff's plans to modify the approach for integrated assessments to implement a graded approach for determining the need for, and prioritization and scope of, plant-specific integrated assessments. As discussed in COMSECY-15-0019, the majority of sites with reevaluated flooding hazards exceeding the design-basis flood are expected to screen out from the integrated assessment process. The licensees will instead provide focused evaluations to ensure appropriate actions are taken and that these actions are effective and reasonable.

The Nuclear Energy Institute (NEI) submitted guidance NEI 16-05, “External Flooding Assessment Guidelines,” Revision 1, on June 10, 2016. The revised guidance is an industry-developed methodology that describes the flooding impact assessment process, which is intended to meet the requested information of an integrated assessment, as described in the document titled, “Request for Information Pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident,” and to incorporate the changes described in COMSECY-15-0019. This revised guidance will be publicly available and used by members of the industry to help develop their responses to the § 50.54(f) letter, including the performance of focused evaluations and integrated assessments, and by the NRC staff in its reviews of the licensees' evaluation.

On April 22, 2016 (81 FR 23758), the NRC requested public comments on draft JLD-ISG-2016-01. The NRC staff received comments from two stakeholders which were considered in the development of the final JLD-ISG-16-01. The questions, comments, and staff resolutions of those comments are contained in “NRC Responses to Public Comments: Revision to Japan Lessons-Learned Division Interim Staff Guidance JLD-ISG- 2016-01: Guidance for ( printed page 46972) Activities Related to Near-Term Task Force Recommendation 2.1, Flooding Hazard Reevaluation; Focused Evaluation and Integrated Assessment” (ADAMS Accession No. ML16165A103).

II. Congressional Review Act

This JLD-ISG is a rule as defined in the Congressional Review Act (5 U.S.C. 801-808). However, the Office of Management and Budget has not found it to be a major rule as defined in the Congressional Review Act.

III. Availability of Documents

The documents identified in the following table are available to interested persons through one or more of the following methods, as indicated.