Wednesday, August 05, 2015

Why SMRs Should Have Smaller Emergency Planning Zones

Marcus Nichol and David Young
The following is a guest post by Marcus Nichol and David Young of NEI.

In a recent decision, the Nuclear Regulatory Commission directed the agency staff initiate a rulemaking to revise emergency preparedness (EP) regulations and guidance for Small Modular Reactor (SMR) facilities. Small, scalable nuclear energy facilities are anticipated to become an important addition to the nation's electric power grids. However, in order for SMRs to fulfill this promise, it is important that an EP framework for these facilities recognize their advanced design characteristics and safety features.

Nuclear power plants must have plans in place to cope with any possible emergency. For the current fleet of large light water reactors (LWRs), these plans include two Emergency Planning Zones (EPZs) around each nuclear power plant facility – one of about 10 miles for actions to protect from a possible radioactive plume (a plume exposure pathway EPZ) and the other of about 50 miles for monitoring potential contamination of food and water supplies (an ingestion exposure pathway EPZ). Compared to large LWRs, an accident at an SMR facility can be expected to result in a much smaller and slower release of radioactivity to the environment, and thus have significantly reduced offsite consequences. For this reason, an SMR facility should be able to justify EPZs that are smaller than those required for a large LWR, along with a commensurate reduction in the amount of resources directed to EP activities.
NuScale SMR facility (artist's conception).
Although the effort to establish an EP framework appropriate for SMRs is underway, significant work remains to provide the regulatory clarity, predictability, and stability needed for the deployment of these facilities. To support this goal, NEI submitted a white paper that proposes EP regulations and guidance for SMR facilities, and is intended to serve as a vehicle for engagement with the NRC. The industry’s proposed requirements will maintain the important role that EP plays in providing defense-in-depth for the protection of public health and safety.

Clinch River site (approximately 40 miles west of Knoxville)
Details on how the industry plans to implement EP for SMRs are expected to be submitted to the NRC soon. First, in early 2016, TVA Nuclear is expected to seek approval for an Early Site Permit (ESP) associated with its Clinch River site and, in support of its request, include two proposed emergency plans – one with a plume exposure pathway EPZ boundary at about 2 miles and the other with a plume exposure pathway EPZ encompassing only the Owner Controlled Area (i.e. a site-boundary EPZ). TVA's approach reflects the fact that the different SMR technologies may need different EPZ sizes. The first vendor application for certification of an SMR design will be submitted by NuScale in late 2016 and followed by the first SMR facility combined license application from the Utah Associated Municipal Power Systems (UAMPS) in late 2017 or early 2018.

We look forward to engaging with the NRC and other stakeholders to define EP requirements for SMRs in support of industry’s upcoming SMR applications.

No comments: