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A Short History of Nuclear Power in Japan

By Kennedy Maize

Washington, D.C., March 14, 2011, 10:05 a.m. – Only France has been more resolute about relying on nuclear power than Japan. The reasons for both countries’ nuclear energy policies are generally the same: neither possesses much in the way of domestic energy resources. So nuclear power – including breeder reactors and a plutonium-uranium fuel cycle – is understandable.

The Federation of Electric Companies of Japan on its website says:

“Energy is the ‘life blood’ of any economy, but for Japan, this truism takes on added importance. Just a few simple facts should help to make it clear that Japan is poor in natural resources, specifically sources of energy, which are so vital to a healthy, modern economy:

*Japan must import over 80% of all primary energy needs

*Japan obtains only 0.3% of its crude oil supply from domestic sources

*Japan has very few domestic sources of coal, natural gas, or uranium.”

Japan features a complicating factor not present in France. Japan is very seismically active. The islands are part of a chain – the “ring of fire” – that describes an arc from New Zealand across Japan, reaching north to Russia’s Kamchatka Peninsula and east to Alaska’s Aleutian Islands. Japan sits where the Eurasian and Pacific tectonic plants crash together, producing earthquakes and volcanoes in profusion. This fact has complicated Japan’s nuclear ambitions from the start.

Japan’s romancing of the atom began in 1954 – the same year the U.S. adopted its second major piece of atomic energy legislation, the Atomic Energy Act of 1954, supplanting the 1946 law passed after World War II (and the U.S. dropping of two atom bombs on Japan). The new U.S. law aimed at refocusing U.S. efforts toward peaceful uses of the atom, although it largely failed in this goal for the next 10 years. Japan allocated funds to nuclear power R&D in 1954. The next year, Japan’s Atomic Energy Basic Law went into effect, limiting the nation’s pursuit of fission power to peaceful purposes only but putting the country on the path to serious nuclear power development.

In part because of early limits on export of U.S. atomic energy technology, Japan initially turned to Great Britain for help with civilian nuclear power. Japan’s first reactor was Tokai 1, a British-designed Magnox reactor (CO2 cooled and graphite moderated, using natural, un-enriched uranium as fuel). It was rated at 166 MW. Construction began in early 1961 and was completed in late 1965. The unit operated at the Tokai station until March 1998. Magnox nuclear technology proved a dead end, both in Britain and Japan. The Japanese soon shifted their attention to U.S.-designed light water reactors, both boiling water designs and pressurized water reactors. Fukushima Daiichi 1, for example, was a General Electric boiling water reactor. Construction started in 1967 and the plant went into commercial service in late 1970.

While Japan continued to procure nuclear steam supply systems from U.S. vendors, the country also began developing its own design and manufacturing technology. According to a paper published by the World Nuclear Association and updated in February, “By the end of the 1970s the Japanese industry had largely established its own domestic nuclear power production capacity….” According to the WNA, the first indigenous Japanese plants had performance problems, with capacity factors averaging below 50%. The country embarked on a program to improve nuclear performance and brought the plants up to world standards by the mid-1980s.

Japan, prior to the March earthquake and tsunami, had 54 operating reactor units with total capacity of slightly over 46 GW, providing about a third of Japan’s electricity. Two additional reactors are under construction, with design capacity of another 2,800 MW. Japan has also embarked on an ambitious, and troubled, breeder reactor program and a plan for reactors to burn mixed uranium-plutonium oxide fuel in thermal plants. Japan started up the 280-MW Monju prototype fast breeder reactor in 1994, but sodium coolant leaks and a subsequent fire shut the plant down in December 1995. There was an official cover up of the accident and widespread public outrage that kept the plant out of service for some 15 years. It restarted last May. Whether it was affected by the events of this month is not clear.

In September 1999, workers at the Tokaimura fuel facility were readying 18.8% enriched fuel for an experimental breeder when they allowed so much uranium in a mixing vessel that the material reached critical mass, exposing the workers to radioactivity and causing a local evacuation. Two of the three workers handling the material when it went critical later died of radiation poisoning. The International Atomic Energy Agency attributed the accident to “human error and serious breaches of safety principles.”

Japan’s conventional nuclear program has had its share of problems, including earthquake-related outages. In 2002, Japan’s regulators forced Tokyo Electric Power Co. to shut down all 17 of its reactors after company officials were charged with falsifying safety documents. They resumed service in 2005. A 2004 pipe break in the turbine building for one of the PWRs at the Mihama plant killed five workers and injured six others. In 2005, a 1970-vintage BWR at the Onagawa station shut down after an earthquake, following indications by plant seismic monitors that the plant had experienced shocks beyond its design basis. Later evaluation found no reactor damage, but the plant was shut down for five months. A July 2007 earthquake led to an extended outage at the Kasiwazaki-Kariwa plant, which caused considerable damage to non-safety related equipment, but not to critical elements of the plant.

None of Japan’s past nuclear power problems even approach the magnitude of what has happened in the aftermath of last week’s earthquake and subsequent tsunami.

For those inclined to do their own background research, here are some links, in no particular order:

Sandia National Laboratory pdf on BWR containments (everything you might want to know about BWR containments)

http://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr6906/cr6906.pdf

U.S. Nuclear Regulatory Commission

http://www.nrc.gov/

Federation of Electric Power Companies of Japan

http://www.japannuclear.com/about/about.html

World Nuclear News, a publication of the World Nuclear Association

http://www.world-nuclear-news.org/RS_Battle_to_stabilise_earthquake_reactors_1203111.html

International Atomic Energy Agency, Facebook page, providing updates

http://www.facebook.com/note.php?note_id=201587349871059

Nuclear Energy Institute

http://www.nei.org/

Union of Concerned Scientists

http://www.ucsusa.org/

Nuclear Information of Resource Service

http://www.ucsusa.org/

Tokyo Electric Power Co.

http://www.tepco.co.jp/en/index-e.html

Japan Nuclear Problems Escalate

By Kennedy Maize

Washington, D.C., March 12, 2011, 10:30 a.m. EST – For those who covered both the Three Mile Island and Chernobyl nuclear disasters, there is an eerie symmetry with what is happening in Japan. In the prior cases – much different from each other and, most likely, very different from what is happening at Fukushima prefecture – the events began with official attempts to downplay the size and scope of the events. As time passed, it became clear that what actually occurred was far worse than what industry and government officials were peddling. They were downplaying the events, in part to prevent fear and panic, in part to cover their posteriors.

In the case of TMI, it took literally months to determine just what happened inside the reactor and how bad the event really was. In the case of Chernobyl, the Soviet Union found it impossible to hide the visual and physical effects of the explosion of the RBMK graphite-moderated, water-cooled reactor. But they tried. Similarly, it is impossible to downplay the visual impact of the explosion at the Fukushima Daiichi 1 plant. A video showing the explosion, demonstrating that this was a major event, is available on YouTube.

The actions of Japan’s nuclear regulator, the Nuclear Industrial and Safety Agency (NISA), demonstrate the serious nature of the events in Japan. The agency first ordered a six-kilometer evacuation in the area surrounding Daiichi 1, then expanded that to 10-km, and, most recently, to 20-km. According to the International Atomic Energy Agency, NISA has also ordered a 10-km evacuation at the Danini nuclear station. According to the IAEA, Japan is planning to “distribute iodine to residents in the area of both plants,” strongly suggesting that I-131, a fission product from damaged fuel, has been found offsite. The IAEA’s reference to distributing iodine is almost certainly means distribution of potassium iodide (KI), which blocks the uptake of radioactive iodine in the thyroid. Radioactive iodine can cause thyroid cancers. According to Nuclear Regulatory Commission historian Samuel Walker, U.S. and Pennsylvania authorities strongly considered distributing KI around Harrisburg, Pa., after the Three Mile Island accident, but backed away from the plan for fear it would cause further panic in the population.

The New York Times in this morning’s edition reported, “Officials said even before the explosion that they had detected cesium, an indication that some of the nuclear fuel was already damaged.” This is further evidence of fuel damage and off-site radiation, particularly troubling if true.

As the event proceeded yesterday evening (in the U.S.), it soon developed that two reactors were having serious cooling water problems: Daiichi 1 and Danini 1, also located in Fukushima Prefecture near the Daiichi complex. To keep things straight, here’s the rundown of the Japanese units and stations involved, courtesy of the World Nuclear Association’s plant database. There have been press reports that other reactors in the two Fukushima Prefecture nuclear stations have suffered core cooling emergencies.

The stations are all owned and operated by Tokyo Electric Power Co., and all are General Electric boiling water reactors, which went into service between 1971 and 1982. Daiichi 1 is a 439-MW reactor that went into service in 1971. Daiichi 2 is a 760-MW unit that began operating in 1974, followed by Daiichi 3 (760 MW) in 1976, Daiichi 4 (760 MW) in 1978, Daiichi 5 (760 MW) in 1978, and Daiichi 6 (1067 MW) in 1979. Two advanced BWRs are planned for the Saiichi site.

Fukushima Daini 1 is a 1067-MW BWR that began operating in 1982, followed by 1067-MW units 2 (1984), 3 (1985), and 4 (1987). According to the WNA, Japan’s 54 nuclear units provide 30% of the country’s electricity, expected to rise to 40% by 2017.

I covered both TMI from 1979 through the 1980s and Chernobyl from 1986 on. Based on my personal experience, here are some guidelines when viewing reading about what has been transpiring in Japan.

First, don’t accept anything at face value, particularly information and opinion offered by government and industry officials. The immediate industry and government response at TMI was a tissue of misstatements, misunderstandings, and, in some cases, outright lies. As time passed, the NRC became a credible source of information, but not initially. No one knew what was going on for quite some time. In the case of Chernobyl, the first instinct of the Soviet Union was to cover up, and they stuck to their guns until it was obvious they were lying. Eventually, led by President Gorbachev, the Soviets came clean.

Next, treat anything activists on either, or any, side of events say for what it is: speculation at best and, most likely, special interest pleading. Anti-nukes will try to fit the events as they emerge into their particular policy and political mold. They will exaggerate the dangers and damages. Industry will do the same, in the opposite direction. Don’t accept anybody’s conclusions as definitive. Discount anything offered by graybeards and chin-stroking wise people on television.

Don’t expect journalists thrown into the story with little or no background to have much to contribute to the story. For the most part, the folks covering the story know nothing about nuclear power details. The best to expect is accuracy in reporting what folks who do know something have to say. There is also a language problem, made worse by an industry that sometimes uses language to conceal and confuse. That’s going to be a double problem when the officials are Japanese and the reporters speak, write and think in English. That was a big problem with Chernobyl, where the officials were speaking and writing in Russian, and the plant design was unlike anything seen in the U.S.

Finally, expect the worst and be happy if you are wrong. These events, and even lesser problems such as the head-rot at First Energy’s Davis Besse plant a few years ago, tend to go from bad to worse.

More to come as events evolve.

What’s Happening in Japan

By Kennedy Maize

Washington, D.C., March 11, 2011 – At this writing, 7:45 p.m. EST, it is hard to be optimistic about what is happening at Japan’s Fukushima 1 nuclear power plant. Matt Wald of the New York Times reports, based on Japanese accounts, that radiation levels in the control room are “1,000 times above normal” and there is some evidence of off-site radiation.

This suggests to me – and it is far too soon to offer definitive opinions – that there has been fuel damage in the 439-MW boiling water reactor. If that is the case, it seems likely that it resulted from one of the most feared accident conditions that can hit a functioning light-water nuclear plant – what’s known in the industry as “station blackout.” That’s when offsite power to the plant – power which runs the main and emergency cooling systems – fails and backup diesel generators on site for the purpose of keeping vital safety systems running also fail.

When a nuclear plant shuts down suddenly, the threat that exists is not radiation. The cooling water is also the nuclear moderator; without a moderator, the chain reaction ceases. Control rods would also automatically activate to stop an uncontrolled fission reaction. But there is a tremendous amount of heat left in the fuel – known as “residual heat” – that must be removed to prevent the fuel from breaking apart, melting and releasing radioactive products of the fission reaction.

At the point that the plant lost backup AC power, it would rely on batteries to keep the pumps running and the core covered with cooling water. But batteries have a limited life. The Times cites the International Atomic Energy Agency as saying that mobile generators have been moved to the plant to provide power for core cooling pumps. The radiation reports suggest that fuel has already been damaged, perhaps melted, releasing radiation on site.

Ed Lyman of the Union of Concerned Scientists, in a briefing paper today, explains the details of the emergency core cooling system at the plant: “The boiling water reactors at Fukushima are protected by a Reactor Core Isolation Cooling (RCIC) system, which can operate without AC power because it is steam-driven and therefore does not require electric pumps. However, it does require DC power from batteries for its valves and controls to function.

“If battery power is depleted before AC power is restored, however, the RCIC will stop supplying water to the core and the water level in the reactor core could drop. If it drops far enough, the core would overheat and the fuel would become damaged.”

The risk to the public, as Japanese officials have stressed, are minimal. The amount of radiation that is likely to escape the site is small. But boiling water reactors, including the 40-year-old Japanese unit, do not have the large, dry concrete-and-steel containment domes that protect pressurized water reactors, so a radiation leak is more likely for a BWR. This has been a contention of the UCS for decades. I won’t go into the intricacies of arguments over BWR versus PWR containments here, but the debate has been going on for a long time.

According to a fact sheet from the Nuclear Information and Resource Service, an anti-nuclear group, the Fukushima station consists of six General Electric BWRs. Unit 1 went into service in in 1971. Units 2,3,4, and 5 are all 760-MW boilers that went into service between 1974 and 1978 and Unit 6, at 1067 MW, went commercial in 1979. The five earliest units all have Mark 1 containments, known among industry folks, as “light bulb and donut” containments for the way they look, which are design to channel steam in an accident through water, reducing the steam pressure on the surrounding structures. All BWRs feature “pressure suppression” containments.

After initially evacuating a three-kilometer zone around the plant, Tokyo Electric Power Co. this afternoon (our time) expanded that to 10 kilometers. There have been uncorroborated reports that Fukushima 2 also lost emergency backup power. The other four operating units at the plant some 200 miles north of Tokyo reportedly shut down as designed as backup generators kicked on to supply cooling water.

I’ll update this blog as more details emerge, which, given the past history of serious nuclear accidents, is likely to occur over a long period of time.

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