The Nuclear Regulatory Commission has voted to approve changes to the emergency preparedness regulations for existing nuclear power plants, research and test reactors and for those that might be licensed and built in the future.

Changes to the rule include: limitations on the duties of onsite emergency responders during an emergency event as well as requirements to incorporate hostile-action-based scenarios in drills and back-up measures for alerting and notification systems.

The new rule also requires nuclear power plants to update their evacuation time estimates after every U.S. Census or when changes in population would increase the estimate by either 25% or 30 minutes, whichever is less.

“Although there are likely to be lessons learned from Japan that will apply to emergency preparedness, I do not think that we need to wait to implement the many enhancements that this rule will provide,” said NRC chairman Gregory Jaczko.

The proposed rule was first put before the Commission in 2006. Since then it has been subject to a lengthy public comment period. It will become effective 30 September 2011.

FilesReactor-by-reactor Fukushima Daiichi restoration progress summary as of 30 August, from JAIF

Fukushima Daiichi spent fuel pool water sampling results