Exelon officials have said that the PBMR design will have a containment, while the NRC has said that it is an issue for discussion as the pre-application and application review proceeds.
The issue of containment versus confinement resurfaced at a public workshop at NRC. Rod Krich, Exelon’s director of licensing, said the plant design has a containment, though it would have different characteristics from a traditional PWR containment.
Antinuclear groups in the USA are adamant that a traditional leak-tight containment is necessary for last resort protection of a plant. However, Dana Powers, a member of NRC’s Advisory Committee on Reactor Safeguards, believes that the technology should dominate this debate. Powers noted that all US nuclear plants have containments, while nuclear materials production reactors operated by the DoE are protected by confinements. “Each concept has its advantages and disadvantages. The real issue is whether the proposed confinement concept provides the level of accident mitigation consistent with the defence-in-depth safety philosophy.” In addition to the ongoing technical discussions, legal and financial issues could also determine whether a PBMR might be built in the USA. The NRC has taken a preliminary position that multiple reactor modules of the same design can be included in a single combined construction- operation licence (COL). But the term of the licence would be limited to 40 years from the issuance of the COL, regardless of when the final module was built, and the duration of the design approved within the COL should be limited to five years.
