Design approval for the ESBWR

17 September 2014

The US Nuclear Regulatory Commission (NRC) has approved a rule to certify GE-Hitachi Nuclear Energy's Economic Simplified Boiling-Water Reactor (ESBWR) design for use in the USA. The rule will go into effect 30 days after its publication in the Federal Register.

An artistic impression of a plant based on the ESBWR (Image: GEH)

The NRC conducted an extensive technical evaluation of the design and issued a safety evaluation report in March 2011. The certification rule notice includes discussion of both public comments on a March 2011 proposed rule, as well as information in petitions submitted to the NRC after the Fukushima nuclear accident in Japan.

The NRC supplemented the draft certification rule in May this year to account for changes in analysis of the design's steam dryer, which prevents excess moisture from damaging a nuclear power plant's electricity-generating turbine. NRC reviewers asked for additional steam dryer information from GE-Hitachi (GEH) between 2011 and 2013. The staff's examination of that information led to the supplement, which also formally incorporated several dozen reference documents as requirements in the draft certification rule. The NRC received no comments on the supplemental rule.

GE-Hitachi Nuclear Energy submitted its application for ESBWR certification in August 2005.

Design certification "marks a crucial step forward for the ESBWR's commercial advancement globally," Caroline Reda, GEH president and CEO said.

GEH said it expected the final ESBWR design certification rule to be published in the Federal Register by the end of September.

The agency is currently reviewing two combined  construction and operating licence applications referencing the GEH design. Detroit Edison is seeking a licence for Fermi 3 in Monroe County, Michigan, which GEH said is expected to be issued in 2015. Dominion Virginia Power is seeking a licence for North Anna Unit 3 in Louisa County, Virginia, which GEH expects to be issued in 2016.

The ESBWR is a 1594 MWe, natural circulation reactor. The design includes passive safety features that would cool down the reactor after an accident without the need for human intervention. These passive features include enhanced natural circulation via a taller reactor vessel, a shorter core and improved water flow through the vessel; an isolation condenser system to control water levels and remove decay heat while the reactor is pressurized, and; a gravity-driven cooling system to maintain water levels when the reactor pressure has dropped.

The NRC has certified four other standard reactor designs - the Advanced Boiling Water Reactor, System 80+, AP600 and AP1000.

Researched and written
by World Nuclear News