The U.S. Nuclear Regulatory Commission (NRC) said it plans to finalize three Interim Staff Guidance (ISG) orders pertaining to U.S. nuclear power plants by August. The orders were issued to nuclear plants in March in response to lessons learned from the accident at the Fukushima Daiichi plant in Japan.
The public comments period on the draft ISGs will be available from June 7 to July 7 once they are published in the Federal Register. The compliance deadline for the ISGs is set for Dec. 31, 2016. The ISGs are not mandatory, but U.S. nuclear power plants would have to seek NRC approval if they wanted to follow a different compliance approach.
The first order requires all U.S. plants to better protect portable safety equipment put in place after the Sept. 11 terrorist attacks and to obtain sufficient equipment to support all reactors at a given site simultaneously. The draft ISG for this order incorporates the industry’s FLEX approach to dealing with any scenario that knocks out all of a plant’s alternating current electric sources. The staff concludes that approach will successfully implement the order.
The second order applies only to GE (NYSE: GE) Mark I or Mark II boiling water reactors, the same reactors used at the Fukushima Daiichi plant. Mark I reactors must improve installed venting systems that help prevent or mitigate core damage in the event of a serious accident, while Mark II reactors must install these venting systems. The draft ISG for this Order provides more detail on technical requirements for the vents, as well as how vent designs and operating procedures should avoid, where possible, relying on plant personnel taking actions under hazardous conditions.
The third order requires all plants to install enhanced equipment for monitoring water levels in each plant’s spent fuel pool. The draft ISG for this order incorporates an industry document that the staff concludes will successfully implement the order. The ISG defines in more detail the water levels the new equipment must accurately report, as well as standards for equipment mounting, powering and testing, personnel training and other criteria.
The NRC also issued an information request in March 2012, including earthquake and flooding hazard walkdowns, during which engineers verify that the plants conform to their current license requirements. The NRC has issued final guidance covering these walkdowns, which includes incorporation of industry documents that the staff concludes will lead to appropriate reviews for all U.S. nuclear power plants.
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