WASHINGTON (AP) -- The Nuclear Regulatory Commission is ordering sweeping safety changes for U.S. nuclear power plants, triggered by the crisis in Japan.
Orders issued Friday require U.S. nuclear plants to install or improve venting systems to limit core damage in a serious accident, and to install sophisticated equipment to monitor water levels in pools holding radioactive spent fuel-rods.
The plants also must improve protection of safety equipment installed after the 2001 terrorist attacks.
The orders are the first issued by the NRC since the March 11 earthquake and tsunami that crippled Japan's Fukushima Dai-ichi nuclear plant.
Responding to the Japan crisis, an NRC task force recommended changes last year designed to increase protection at the 104 U.S. nuclear reactors.
U.S. plants must comply with the orders by the end of 2016.