The Nuclear Regulatory Commission is directing virtually every commercial U.S. nuclear powerplant to meet new safety requirements, which the commission says it is putting in place as a result of lessons learned from Japan's  March 2011 Fukushima disaster.

The NRC, in a March 9 announcement, said it has instructed its staff to issue three orders to  operators of U.S. commercial nuclear reactors. The directives apply to all reactors currently operating or under construction, as well as to those planned and recently licensed at the Southern Nuclear Operating Co.'s Vogtle site in Georgia.

One of those orders requires plants to provide better protection for safety equipment installed after the Sept. 11, 2001,  terrorist attacks and also to obtain sufficient equipment to support all reactors at each site simultaneously.

The second order requires plants to install enhanced equipment for monitoring water levels in each facility's spent-fuel pool.

The third applies only to U.S. boiling-water reactors that have “Mark I” or “Mark II” containment structures. NRC is requiring those reactors to improve venting systems—or for the Mark II plants, install new systems—that help prevent or mitigate core damage in the event of a serious accident.

Plants have until Dec. 31, 2016, to complete modifications and requirements called for under all three NRC orders.

NRC Chairman Gregory B. Jaczko said, “The commission has taken a significant step forward on our post-Fukushima efforts. These orders reflect a tremendous effort on the part of the NRC staff to produce this comprehensive package in an expedited manner."

The commision also will issue requests for information to each operating U.S. commercial nuclear powerplant and certain provisions will apply to reactors under construction or recently licensed. For example, NRC will ask operators to carry out analyses of earthquake and flooding risks using up-to-date information.

The orders put into place the highest-priority recommendations of the agency’s Japan Near-Term Task Force, which issued a report last July.