Nuclear crisis in Japan - March 13
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Japanese Scramble to Avert Meltdowns as Nuclear Crisis Deepens After Quake
Hiroko Tabuchi and Matthew L. Wald, New York Times
Japanese officials struggled on Sunday to contain a widening nuclear crisis in the aftermath of a devastating earthquake and tsunami, saying they presumed that partial meltdowns had occurred at two crippled reactors and that they were facing serious cooling problems at three more.
The emergency appeared to be the worst involving a nuclear plant since the Chernobyl disaster 25 years ago. The developments at two separate nuclear plants prompted the evacuation of more than 200,000 people.
(12 March 2011)
Meltdowns Grow More Likely at the Fukushima Reactors
Robert Alvarez, CommonDreams.org
A hydrogen explosion yesterday at Unit 1 severely damaged the reactor building, blowing apart its roof.
Japan's government and nuclear industry, with assistance from the U.S. military, is in a desperate race to stave off multiple nuclear reactor meltdowns — as well as potential fires in pools of spent fuel.
As of Sunday afternoon, more than 170,000 people have been evacuated near the reactor sites as radioactive releases have increased. The number of military emergency responders has jumped from 51,000 to 100,000. Officials now report a partial meltdown at Fukushima's Unit 1. Japanese media outlets are reporting that there may be a second one underway at Unit 3. People living nearby have been exposed to unknown levels of radiation, with some requiring medical attention.
Meanwhile, Unit 2 of the Tokai nuclear complex, which is near Kyodo and just 75 miles north of Tokyo, is reported to have a coolant pump failure. And Japan's nuclear safety agency has declared a state of emergency at the Onagawa nuclear power plant in northeastern Japan because of high radiation levels. Authorities are saying its three reactors are "under control."
The damage from the massive earthquake and the tsunamis that followed have profoundly damaged the reactor sites' infrastructure, leaving them without power and their electrical and piping systems destroyed. A hydrogen explosion yesterday at Unit 1 severely damaged the reactor building, blowing apart its roof.
The results of desperate efforts to divert seawater into the Unit 1 reactor are uncertain. A Japanese official reported that gauges don't appear to show the water level rising in the reactor vessel.
There remain a number of major uncertainties about the situation's stability and many questions about what might happen next. Along with the struggle to cool the reactors is the potential danger from an inability to cool Fukushima's spent nuclear fuel pools.
Robert Alvarez, an Institute for Policy Studies senior scholar, served as senior policy adviser to the Energy Department's secretary and deputy assistant secretary for national security and the environment from 1993 to 1999.
(13 March 2011)
US lawmakers say go slow on nuclear energy
AFP via Yahoo! News
The unfolding nuclear disaster in Japan at reactors damaged by a massive earthquake and tsunami has led some lawmakers to call for putting the "brakes" on US nuclear development.
"I've been a big supporter of nuclear power because it's domestic -- it's ours and it's clean," Senator Joseph Lieberman told the CBS News television program "Face The Nation" Sunday.
Nevertheless "I think we've got to ... quietly and quickly put the brakes on until we can absorb what has happened in Japan as a result of the earthquake and the tsunami," said Lieberman, who is chairman of the Senate Homeland Security Committee.
... President Barack Obama wants to increase nuclear power as part of a US effort to decrease the nation's dependence on coal and foreign oil. The administration has allocated $18.5 bn in Department of Energy loan guarantees to spur nuclear development.
(13 March 2011)
Related from NY Times: U.S. Nuclear Industry Faces New Uncertainty:
The fragile bipartisan consensus that nuclear power offers a big piece of the answer to the America’s energy and global warming challenges may have dissolved in the crippled cores of Japan’s nuclear reactors.
Japan nuclear fears as systems fail at second reactor
Jonathan Watts, Justin McCurry and Robin McKie, Guardian
... In the wake of the impact of Friday's earthquake and tsunami, the Fukushima incident has strained life in Japan to an almost unendurable level, and although catastrophe appears to have been averted the incident has raised serious concerns about Japan's enthusiastic use of nuclear energy.
Reactors generate almost a third of the country's electricity and there are plans, already well advanced, to raise this to 50%. For the nuclear industry, the Fukushima incident could not have come at a worse time. Unravelling what happened and how close the nation came to disaster will preoccupy scientists and engineers for years.
It will be a complex business, as John Luxat, professor of nuclear safety analysis at McMaster University in Ontario, makes clear. "When the quake hit the reactors at Fukushima, three were up and running – the other three were shut down for regular inspection," he said.
"The three that were running shut down immediately, as they are designed to do when the ground shakes above a certain level. After that, the emergency back-up diesel generators that provide electricity to the shutdown cooling system operated as designed for about an hour. Then they failed for some reason that's not clear. They lost power to the pumps providing cooling water."
Last night reports suggested that the emergency pumps had failed because they had been swamped by the tsunami triggered by the initial earthquake – an embarrassing failure by those who had planned the reactor's back-up systems.
Whatever the reason, the consequences were dramatic. Without pumps taking away the water that acted as the coolant, the reactors heated up and steam built up inside.
"To reduce the pressure, you would have to release some steam into the atmosphere from the system," said Paddy Regan, professor of nuclear physics at Surrey University. "In that steam, there will be small but measurable amounts of radioactive nitrogen 16 [produced when neutrons hit water]. This remains radioactive for only about five seconds, after which it decays to natural oxygen."
The steam that built up inside the damaged reactor was released into the reactor housing, outside the containment vessel. The aim was to vent it, but before that could happen there was an explosion. A huge cloud of smoke erupted from the plant, injuring a number of workers.
Government spokesman Yukio Edano said that the explosion had destroyed the exterior walls of the building where the stricken reactor is located, but not the actual metal housing that enveloped the reactor.
However, it is still possible the reactor could have sustained serious damage. If its fuel rods reached too high a temperature, they would have melted at least partly. "If any of the fuel rods have been compromised, there would be evidence of a small amount of other radioisotopes in the atmosphere called fission fragments – radiocaesium and radioiodine," said Regan.
(13 March 2011)
Nuclear plant issues in Japan are the least of their worries
Rod Adams, Atomic Insights
... The aftermath of this event will be a long and difficult clean up. Even in a well ordered and wealthy society like the one that exists in Japan, there will be places where physical evidence of the disaster will be detectable for decades. No one alive in Japan today will ever forget where they were on the afternoon of March 11, 2011. I can make those statements in such a positive manner because the record of recoveries from extensive natural disasters is as long as recorded human history; there is no reason to believe that this one will be substantially different.
What is incredible to me, however, is that there are many people who are focusing on the wrong thing and worrying about low consequence details of the damage that should only be a major concern for the people who are directly involved in accident response. I know it is hopelessly rational of me, but when faced with a confusing array of dangers, I have been trained to handle the ones most likely to hurt me or my loved ones first. Prioritization and triage are important tools in damage control; wasting resources on those aspects that are being well handled means you have less time and tools available to respond to the really pressing details.
There is at least one nuclear power plant that is apparently in danger of suffering long term damage. The operators are doing what they have been trained to do and working hard to keep their already shut down nuclear core covered with cooling water as the fission products decay away. Because they are in a place where all basic services have been cut off, getting electricity to their cooling water supply pumps is a serious challenge. As hospitals in Louisiana found out after Katrina, emergency diesel generators only supply power if you also manage to continue to deliver a sufficient supply of fuel to keep them running.
The almost certain scenario at all of the nuclear plants in Japan is that all of the hazardous material will be contained within the carefully engineered and constructed reactor pressure vessels and the surrounding containment building that were installed before the plants were ever started. During the course of events, there will almost certainly be a need for at least some of the the plant operators to carefully release non-condensible gases from their containment building. Some of those gases will be chemically inert "noble" gases that contain radioactive isotopes. No one will receive a high enough dose of radiation to cause any negative health effects.
I have no first hand knowledge of the specifics at the Fukushima Daiichi nuclear plant, or at the Fukushima Daini plant or any of the other plants that might experience similar challenges during the next few days. However, I spent a decade or so being trained and serving as an operator and department head for a nuclear power plant cooled by ordinary water (what we call "light water"). That deeply engrained experience helps me to have a pretty fair idea what must be going on at standard issue reactor plants constructed to international standards in the case where supplying even emergency electrical power is nearly impossible.
(12 March 2011)
From a pro-nuclear website. -BA
Japan's nuclear crisis: the causes and the risks
Ian Sample, Guardian
How did the explosion at the Fukushima No 1 power station in Japan happen? And what are the consequences?
What caused the nuclear crisis?
Problems began when Friday's massive earthquake knocked out electricity at the Fukushima No 1 power station. Back-up generators kicked in to pump coolant around the reactor cores to prevent the fuel rods from overheating. The generators worked for a short time, but were damaged by the ensuing tsunami, forcing a scramble by engineers to fit mobile battery power units. These were insufficient to cool all of the reactors properly.
(13 March 2011)
Fukushima: Nuclear backgrounder
AFP voa NineMSN
Following is a technical backgrounder on events at the Fukushima plant in northeastern Japan, crippled by a tsunami unleashed by last Friday's 8.9 magnitude quake:
A nuclear reactor produces electricity from pellets of enriched uranium that fit into fuel rods. The energy from nuclear chain reaction heats water, producing steam to drive turbines which in turn produce power. The rods are encased in a steel reactor vessel, which in turn is protected by a containment vessel, essentially a thick shell of reinforced concrete designed to prevent any radioactive gas or material from escaping.
(1X March 2011)
More links on the Japan nuclear crisis
Leanan, The Oil Drum
More than 20 links and much discussion at The Oil Drum.
(13 March 2011)
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