Third explosion reported, 3 cooling systems failing, 3 meltdowns can’t be ruled out, 1 spent fuel pool boiled over
"Third explosion reported, 3 cooling systems failing, 3 meltdowns can’t be ruled out, 1 spent fuel pool boiled over"
Germany, Switzerland suspend nuclear plans as U.S. right-wing calls for faster nuclear permit process!
The spent fuel scenario I raised last night (detailed below) appears to have begun. The NY Times reports as of Tuesday 9:36 “… late Tuesday Japan’s nuclear watchdog said a pool storing spent fuel rods at that fourth reactor had overheated and reached boiling point and had become unapproachable by workers.” Here’s their front page:
An “explosive impact” occurred Tuesday morning at the No. 2 reactor at the Fukushima Daiichi nuclear power plant in northeastern Japan, a day after a hydrogen explosion rocked another reactor, the plant’s owner said….
Yukio Edano, Japan’s chief Cabinet secretary, said he could not rule out the possibility of a meltdown at all three troubled reactors.…
The situation in Japan is unprecedented, as the CNN story from 7:32 pm EDT makes clear. I don’t believe there’s ever been more than one reactor with a malfunctioning cooling system seriously facing a possible meltdown at one time. Yesterday 2 were and now 3 are simultaneously.
The NY Times has updated a story as of 8:03 pm EDT that lays out the situation and the risks, “New Blast Reported at Nuclear Plant as Japan Struggles to Cool Reactor”:
An explosion early Tuesday morning may have damaged the inner steel containment vessel of the No. 2 reactor at Japan’s Fukushima Daiichi Nuclear Power Station, leading to the wide release of radioactive materials there and forcing the evacuation of some emergency workers, the plant’s operator said.The blast appeared to be different “” and more severe “” than those that at two other troubled reactor at the same nuclear complex because this one, reported to have occurred at 6:14 a.m., happened in the “pressure suppression room” in the cooling area of the reactor, raising the possibility to damage to the reactor’s containment vessel.
Any damage to the steel containment vessel of a nuclear reactor is considered critical because it raises the prospect of an uncontrolled release of radioactive material and full meltdown of the nuclear fuel inside. To date, even during the four-day crisis in Japan that amounts to the worst nuclear accident since Chernobyl, workers had managed to avoid a breach of a containment vessel and had limited releases of radioactive steam to relatively low levels.
The underlying situation is also grave:
The new blast came after emergency operations to pump seawater into the same reactor failed, leaving the nuclear fuel in that reactor dangerously exposed late Monday into early Tuesday morning.Tokyo Electric Power said late Monday that a malfunctioning valve made it impossible to release pressure in the reactor, which in turn thwarted efforts to inject seawater into it to cool the fuel. The water levels inside the reactor’s containment vessel fell and left its fuel rods exposed “” perhaps completely exposed “” for some hours.
Workers had been having difficulty injecting seawater into the reactor because its vents “” necessary to release pressure in the containment vessel by allowing radioactive steam to escape “” had stopped working properly, they said.
In the predawn hours of Tuesday Tokyo Electric announced that workers had finally succeeded in opening a malfunctioning valve controlling the vents, reducing pressure in the container vessel. It then resumed flooding the reactor with water.
But the company said water levels were not immediately rising to the desired level, possibly because of a leak in the containment vessel…..
“They’re basically in a full-scale panic” among Japanese power industry managers, said a senior nuclear industry executive. The executive is not involved in managing the response to the reactors’ difficulties but has many contacts in Japan. “They’re in total disarray, they don’t know what to do.”
It still seems unlike there will be massive amounts of radioactivity released from a meltdown. That said, I listened to a press call today, which included one of my former DOE colleagues, Bob Alvarez, which spelled out a problem potentially equally as large but not receiving much attention.
Sharon Begley, the science columnist and science editor of Newsweek, has a good write-up of the call, “The Japan Nuke Problem No One’s Talking About,” which I’ll excerpt:
To the growing list of worries at the Fukushima Daiichi nuclear-power plant … add this: could the spent nuclear fuel sitting in a nearby storage pool pose an even bigger threat to people and the environment? The spent fuel produced by reactors has been a challenge since the dawn of the nuclear industry, with most reactor operators opting to store it in pools of cooling water on site. At the 40-year-old Fukushima plant, which was built by General Electric, the fuel rods are stored at a pool about three stories up, next to the reactor (a schematic is here). Satellite photos raise concerns that the roof of the building housing the pool has been blown off, says Robert Alvarez, a senior scholar at the Institute for Policy Studies and a senior policy adviser to the secretary of energy and deputy assistant secretary for national security and the environment from 1993 to 1999. He and other experts are now warning that any release of radioactivity from the spent-fuel pool could make the releases from the reactors themselves pale in comparison.
The spent-fuel pools are rectangular basins about 40 feet deep, made of four- to five-foot-thick reinforced concrete lined with stainless steel. That was thought to be sufficient to prevent a breach. But the disastrous combination of an earthquake (which knocked out power form the electricity grid) and a tsunami (which swamped the diesel generators serving as backup power) forced the power-plant operators to turn to batteries for core cooling.When battery-powered cooling failed, hydrogen in two of the units exploded, damaging the reactor buildings””and, apparently, the spent-fuel area as well. Satellite photos appear to show that two cranes used to move spent fuel into the pool “are both gone,” Alvarez told a press conference organized by Friends of the Earth, a nonprofit environmental group that opposes nuclear power. “There has definitely been damage to the pool area.”
The pools “contain very large concentrations of radioactivity, can catch fire, and are in much more vulnerable buildings,” he warns. If the pools lose their inflow of circulating cooling water, the water in the pools will evaporate. If the level of water drops to five or six feet above the spent fuel, Alvarez calculates, the release of radioactivity “could be life-threatening near the reactor building.” Since the total amount of long-lived radioactivity in the pool is at least five times that in the reactor core, a catastrophic release would mean “all bets are off,” he says.
Of particular concern: cesium-137 in the pool, at levels Alvarez estimates at 20 million to 50 million curies. The 1986 Chernobyl accident released about 40 percent of the reactor core’s 6 million curies. In a 1997 report for the Nuclear Regulatory Commission, scientists at Brookhaven National Laboratory estimated that a severe pool fire””made possible by the loss of cooling water””could leave about 188 square miles uninhabitable and cause up to 28,000 cancer deaths.
Once again, warnings from scientists were ignored that could have dramatically reduced the risk here:
The new concern at Fukushima Daiichi highlights an ongoing controversy about the way spent fuel gets stored: what if Tokyo Electric Power had heeded the growing scientific consensus and moved the spent fuel out of the storage pool and into dry, hardened casks for storage? Germany did this 25 years ago. The NRC has rejected this recommendation, but a 2006 analysis by the National Academy of Sciences warned that “breaches in spent fuel pools could be much harder to plug [than those in dry casks], especially if high radiation fields or the collapse of the overlying building prevented workers from reaching the pool. Complete cleanup from a zirconium cladding fire would be extraordinarily expensive, and even after cleanup was completed large areas downwind of the site might remain contaminated to levels that prevented reoccupation.”The NAS report … concluded that “recovery from an attack on a dry cask would be much easier than the recovery from an attack on a spent fuel pool. Breaches in dry casks could be temporarily plugged with radiation-absorbing materials until permanent fixes or replacements could be made … It is the potential for zirconium cladding fires in spent fuel pools that gives dry cask storage most of its comparative safety and security advantages.”
The NRC counts almost 100 spent-fuel pools in the United States.
The NYT has just published a story on this, “In Stricken Fuel-Cooling Pools, a Danger for the Longer Term.”
Both Germany and Switzerland suspended their nuclear plans. The Wall Street Journal reports, “Germany Rethinks Atomic Power”:
Fears of a nuclear disaster in Japan have revived Germans’ angst about atomic energy two weeks ahead of important regional elections, prompting Chancellor Angela Merkel to suspend her contested plan to extend the life of Germany’s nuclear reactors.Ms. Merkel said Monday her government would hold a three-month safety review of Germany’s 17 nuclear reactors while weighing options for drawing more energy from alternative sources.
The AP reports, “Swiss suspend plans for new nuclear plants”:
The Swiss government has suspended plans to replace and build new nuclear plants pending a review of two hydrogen explosions at Japanese plants.
The head of the Swiss federal energy department, Doris Leuthard, said Monday’s suspension affects three requests for “blanket authorization for nuclear replacement until safety standards have been carefully reviewed and if necessary adapted.”