A panel that sought answers today from the Nuclear Regulatory Commission about the crisis at a crippled nuclear power plant in northeast Japan got little satisfaction.
Under questioning by the Advisory Committee on Reactor Safeguards, NRC staff were unable to say who vetted NRC Chairman Gregory Jaczko's recommendation last month that Japan evacuate people living within 50 miles of the Fukushima Daiichi plant, which was damaged by a March 11 earthquake and tsunami.
Japanese officials have maintained an evacuation area of 12 miles around the reactor complex, but Chief Cabinet Secretary Yukio Edano said that decision may be reconsidered after the country was hit today by a 7.4-magnitude aftershock (Greenwire, April 7).
The advisory committee -- which includes part-time government employees with expertise in nuclear engineering, risk assessment and engineering -- voiced concern over the lack of knowledge surrounding Jaczko's high-level statement.
"This is a very, very important decision, and I would have expected there would have been high-level conversations between our regulatory bodies and our government-equivalent people in the Japanese government on the worst-case analysis of why we were doing this," said John Sieber, a panel member and retired senior vice president of Duquesne Light Co.'s nuclear division.
NRC staff said the "conservative" decision to call for a 50-mile evacuation zone was based on assumptions that the spent fuel pool was full of fuel, as are American spent fuel pools. But NRC staff said they were surprised to later learn that the Japanese spent fuel pools were not as packed with nuclear fuel as they would have been in the United States.
Bill Ruland, acting deputy director for engineering and corporate support in the Office of Nuclear Reactor Regulation, said the commission usually does not make "protective action recommendations" but that the agency's role in a U.S. emergency is to determine whether local authorities' or licensee's recommendations are sufficient. In Japan, he said, NRC played a "different role."
But Sieber said that it is "exactly how that role is portrayed in the United States that I'd be concerned about."
NRC staff also could not confirm the validity of an NRC report that Rep. Henry Waxman (D-Calif.) claimed to have obtained at a House Energy and Commerce subcommittee hearing yesterday.
Rep. Ed Markey (D-Mass.), the subcommittee chairman, said a nuclear watchdog group, the Union of Concerned Scientists, obtained the NRC models through freedom-of-information requests and the group had released excerpts from the draft assessment.
The model showed that the Peach Bottom Atomic Power Station in Pennsylvania would come within hours of suffering core damage in the event of a highly unlikely, sustained loss of primary and backup power (Greenwire, April 6).
Markey also said that NRC had told his office the Fukushima plant had kept pace with U.S. nuclear safety requirements and had hardened vents to release hydrogen from the reactor's separation pools.
But commission officials today said they could not confirm whether the damaged reactor's owner, Tokyo Electric Power Co. (TEPCO), was still venting the reactors or if the plant actually has hardened vents.
The advisory panel said the commission should take care that incorrect information is not spread and recommended an immediate investigation.
"Somebody ought to follow up as to why these incorrect facts are getting out," said Michael Corradini, a member of the advisory panel and retired director of the Nuclear Engineering Department at Northeast Utilities in Connecticut.
NRC staff said they learned through media reports that a safety valve on Unit 1 was stuck open on April 5, possibly allowing coolant to flow out of the cooling system and making the system ineffective. But again, NRC could not confirm that information.
TEPCO officials yesterday began injecting Unit 1 with nitrogen gas to "inert the containment" and ensure hydrogen left in the reactor does not mix with oxygen and explode.
NRC staff members said they were not sure if venting was ongoing but that the utility is dealing with the stuck valve on Unit 1. They said they are "working to obtain" up-to-date drawings of the General Electric Mark 1 boiling water reactor, a statement that received smirks from the panel that advised NRC to ask GE for the drawings.
The agency's staff said they were also unsure why Units 5 and 6 at the reactor complex experienced less damage during the earthquake and tsunami, how much used nuclear fuel was in the spent fuel pools or how the rods were arranged.
"I'm sure during the weeks and months ahead, we'll be trying to get that information," Ruland said.
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