MC&A and safety in advanced reactors in focus

Moderator Shikha Prasad was joined by two presenters, John Russell and Lester Towell, who looked at how regulations that were historically developed for traditional light water reactors will apply to the next generation of nuclear technology and what changes need to be made.

MC&A regulations: Russell, who currently serves in the fuel management division of the Nuclear Regulatory Commission as a domestic MC&A analyst, began the presentation by explaining that developing regulations around advanced reactors is complicated by the diversity of design in the field. A wide variety of safety features and reactor sizes presents complex challenges for MC&A.

The differences in fuel types used by advanced reactors also create issues. Molten salts, HALEU, TRISO, and pebble beds all require different approaches to inventorying and measuring that are at odds with current LWR-based regulatory standards, according to Russell.

Safety considerations: While Russell outlined the challenges presented at the system level, Towell, the director of operations at Abilene Christian University’s NEXT Lab where the Molten Salt Research Reactor (MSRR) is being developed, presented a case study in the on the safety features of the MSRR.

Those features include five layers of protection around the salt where the majority of the fission takes place, the low-pressure design of the MSRR, and the ease with which it can be shut down.

The MSRR may also provide a unique opportunity to develop new technologies and techniques in the overlapping worlds of MC&A and safety, security and safeguards—whether that be by testing the effects of radiation and high temperatures on equipment or even developing a digital twin of the reactor.