* NRC should reevaluate threats to plant designs-Feinstein
* NRC is looking at U.S. plants, rules
By Roberta Rampton
WASHINGTON, April 20 (Reuters) - U.S. regulators should set a more rigorous standard for allowing aging nuclear power plants to keep operating, demanding they be as capable of withstanding natural disasters as new facilities, a U.S. senator said on Wednesday.
The Nuclear Regulatory Commission is scrutinizing the United States’ 104 plants after an earthquake and tsunami wrecked Japan’s Fukushima Daiichi nuclear plant in March.
Under existing rules that cover their relicensing, it does not need to reassess exterior threats, only the impact of natural aging, Democratic Senator Dianne Feinstein said.
“I believe that our understanding of many threats — especially seismic threats, tsunami threats, spent fuel risks, and terrorist threats — has improved dramatically since most nuclear power plants were originally designed and licensed thirty or more years ago,” Feinstein said in a letter to NRC Chairman Gregory Jaczko.
An NRC spokesman said Jaczko would review the letter. The agency had no further comment.
Feinstein’s concerns are reminiscent of those raised after the Sept. 11, 2001 attacks, when some lawmakers said relicensing should be contingent on operators proving their plants could withstand a direct hit from an airliner.
The NRC’s relicensing process examines the impact of aging on plants. “The process does not reevaluate the threat assessment that formed the basis of the plant’s original design,” Feinstein said.
Jaczko has said the regulator would not wait for the relicensing process to order any improvements it deems are needed immediately.
Regulatory uncertainty has also impacted plans to build new nuclear power plants in the United States. NRG Energy Inc (NRG.N) said on Tuesday it had abandoned plans to build two reactors in Texas. [ID:nN1954405]
Requiring a review of threats to the design of existing plants during relicensing would put the onus on operators to show plants can withstand disasters, Feinstein said.
Feinstein has said she is concerned about the ability of two plants in her state, California, to withstand earthquakes — Pacific Gas and Electric’s (PCG.N) Diablo Canyon plant and Edison International’s (EIX.N) San Onofre plant.
Earlier this month, PG&E asked the NRC to delay processing an application to extend the life of its Diablo Canyon plant to give it time to complete a seismic study. [ID:nN11113582] (Editing by Dale Hudson)