Nuclear Regulatory Commission November 6, 2008 – Federal Register Recent Federal Regulation Documents

The Nuclear Regulatory Commission (NRC) is considering the issues raised in a petition for rulemaking submitted by Anthony R. Pietrangelo, on behalf of the Nuclear Energy Institute, in the ongoing ``Risk-Informed Redefinition of Large Break Loss-of-Coolant Accident (LOCA) Emergency Core Cooling System (ECCS) Requirements'' rulemaking. The petitioner requested that the NRC amend its regulations to allow the use of an alternative to the currently required double-ended rupture of the largest pipe in the reactor coolant system in ECCS evaluation models.

The Nuclear Regulatory Commission (NRC) is considering the issues raised in a petition for rulemaking submitted by David J. Modeen, on behalf of the Nuclear Energy Institute, in the ongoing ``Performance-Based Emergency Core Cooling System (ECCS) Cladding Acceptance Criteria'' rulemaking (ADAMS accession no. ML020630082). The petitioner requested that the NRC amend its regulations to allow nuclear power plant licensees to use zirconium-based cladding materials other than Zircaloy or ZIRLO, provided the cladding materials meet the requirements for fuel cladding performance and have been approved by the NRC staff. Specifically, the petitioner stated that the NRC's current regulations require uranium oxide fuel pellets, used in commercial reactor fuel, to be contained in cladding material made of Zircaloy or ZIRLO. The requirement to use either of these materials is stated in the regulations that govern combustible gas control and acceptance criteria for emergency core cooling systems for nuclear power reactors. The petitioner noted that subsequent to promulgation of these regulations, commercial nuclear fuel vendors have developed and continue to develop materials other than Zircaloy or ZIRLO. To allow a licensee to use fuel made with these new cladding alloys, the NRC must review and approve an exemption request. The petitioner requested that the NRC amend these regulations to allow licensees discretion to use zirconium-based cladding materials other than Zircaloy or ZIRLO, provided that the cladding materials meet the fuel cladding performance requirements and have been reviewed and approved by the NRC staff.