Plans are afoot to reuse spent reactor fuel in the U.S. But the advantages of the scheme pale in comparison with its dangers

LA HAGUE, on France’s Normandy coast, hosts a large complex that reprocesses spent fuel from nuclear power plants, extracting its plutonium for fabrication into new fuel. The U.S. Depart�ment of Energy has recently proposed building a similar facility.Image: Martin Bond: Photo Researchers, Inc.

Although a dozen years have elapsed since any new nuclear power reactor has come online in the U.S., there are now stirrings of a nuclear renaissance. The incentives are certainly in place: the costs of natural gas and oil have skyrocketed; the public increasingly objects to the greenhouse gas emissions from burning fossil fuels; and the federal government has offered up to $8 billion in subsidies and insurance against delays in licensing (with new laws to streamline the process) and $18.5 billion in loan guarantees. What more could the moribund nuclear power industry possibly want?

Just one thing: a place to ship its used reactor fuel. Indeed, the lack of a disposal site remains a dark cloud hanging over the entire enterprise. The projected opening of a federal waste storage repository in Yucca Mountain in Nevada (now anticipated for 2017 at the earliest) has already slipped by two decades, and the cooling pools holding spent fuel at the nation’s nuclear powerplants are running out of space.

http://www.scientificamerican.com/article.cfm?id=rethinking-nuclear-fuel-recycling

Recycling Nuclear Fuel: The French Do It, Why Can�t Oui?

What if the government allowed you to burn only 25 percent of every tank of gas? Or if Washington made you pour half of every gallon of milk down the drain?

What if lawmakers forced us to bury 95 percent of our energy resources?

That is exactly what Washington does when it comes to safe, affordable and CO2-free nuclear energy. Indeed, 95 percent of the used fuel from America’s 104 power reactors, which provide about 20 percent of the nation’s electricity, could be recycled for future use.

To create power, reactor fuel must contain 3-5 percent burnable uranium. Once the burnable uranium falls below that level, the fuel must be replaced. But this “spent” fuel generally retains about 95 percent of the uranium it started with, and that uranium can be recycled.

Over the past four decades, America’s reactors have produced about 56,000 tons of used fuel. That “waste” contains roughly enough energy to power every U.S. household for 12 years. And it’s just sitting there, piling up at power plant storage facilities. Talk about waste!

The sad thing is, the United States developed the technology to recapture that energy decades ago, then barred its commercial use in 1977. We have practiced a virtual moratorium ever since.

Other countries have not taken such a backward approach to nuclear power. France, whose 59 reactors generate 80 percent of its electricity, has safely recycled nuclear fuel for decades. They turned to nuclear power in the 1970s to limit their dependence on foreign energy. And, from the beginning, they made recycling used fuel central to their program.

Upon its removal from French reactors, used fuel is packed in containers and safely shipped via train and road to a facility in La Hague. There, the energy producing uranium and plutonium are removed and separated from the other waste and made into new fuel that can be used again. The entire process adds about 6 percent in costs for the French.

Anti-nuclear fear mongering has proved baseless. The French have recycled fuel like this for 30 years without incident: no terrorist attack, no bad guys stealing uranium, no contribution toward nuclear weapons proliferaton, and o accidental explosions.

France meets all of its recycling needs with one facility. Indeed, domestic French reprocessing only takes about half of La Hague’s capacity. The other half is used to recycle other countries’ spent nuclear fuel.

Since beginning operations, France’s La Hague plant has safely processed over 23,000 tones of used fuel—enough to power France for fourteen years.

Their success has sparked plenty of interest abroad. The French company AREVA has already helped Japan with its reprocessing facility and is currently looking at the feasibility of building a similar plant in China.

The British, Japanese, Indians, and Russians all engage in some level of reprocessing.

Of course, there is still waste involved. But recycling produces much lower volumes of highly radioactive waste, and the French deal with it effectively—placing some waste in short-term, interim storage or preparing the rest for long-term storage in their version of Yucca Mountain.

All is not perfect in France. They are still working to open a permanent geologic storage facility. But the critical issue is that they have an organization to handle used nuclear fuel that allows their program to advance without being held hostage to the politics of geologic storage.

If the United States is serious about reducing CO2 and energy dependence, it must get serious about nuclear power and begin recycling used nuclear fuel.

A viable reprocessing capability not only would give the United States a valuable energy resource, it would reduce the amount of material going to Yucca Mountain. The U.S. has already produced enough waste to nearly fill Yucca’s legal limit of 70,000 metric tons—subsequent studies estimate that its actual capacity is about double that amount and some believe that it is even greater.

It would also put the United States back on the map as a leader in commercial nuclear technology, which today it is not.

Nuclear fuel reprocessing is a safe activity that should be part of America’s nuclear energy program. It can be affordable and is technologically feasible. The French are proving that on a daily basis. The question is: Why can’t oui?

Jack Spencer is a research fellow for nuclear energy policy in the Thomas A. Roe Institute for Economic Policy Studies.

http://www.foxnews.com/story/0,2933,318688,00.html

Processing of Used Nuclear Fuel

  • Used nuclear fuel has long been reprocessed to extract fissile materials for recycling and to reduce the volume of high-level wastes.
  • New reprocessing technologies are being developed to be deployed in conjunction with fast neutron reactors which will burn all long-lived actinides.
  • A significant amount of plutonium recovered from used fuel is currently recycled into MOX fuel; a small amount of recovered uranium is recycled.

A key, nearly unique, characteristic of nuclear energy is that used fuel may be reprocessed to recover fissile and fertile materials in order to provide fresh fuel for existing and future nuclear power plants. Several European countries, Russia and Japan have had a policy to reprocess used nuclear fuel, although government policies in many other countries have not yet addressed the various aspects of reprocessing.

Over the last 50 years the principal reason for reprocessing used fuel has been to recover unused uranium and plutonium in the used fuel elements and thereby close the fuel cycle, gaining some 25% more energy from the original uranium in the process and thus contributing to energy security. A secondary reason is to reduce the volume of material to be disposed of as high-level waste to about one fifth. In addition, the level of radioactivity in the waste from reprocessing is much smaller and after about 100 years falls much more rapidly than in used fuel itself.

In the last decade interest has grown in recovering all long-lived actinides together (i.e. with plutonium) so as to recycle them in fast reactors so that they end up as short-lived fission products. This policy is driven by two factors: reducing the long-term radioactivity in high-level wastes, and reducing the possibility of plutonium being diverted from civil use – thereby increasing proliferation resistance of the fuel cycle. If used fuel is not reprocessed, then in a century or two the built-in radiological protection will have diminished, allowing the plutonium to be recovered for illicit use (though it is unsuitable for weapons due to the non-fissile isotopes present).

Reprocessing used fuela to recover uranium (as reprocessed uranium, or RepU) and plutonium (Pu) avoids the wastage of a valuable resource. Most of it – about 96% – is uranium, of which less than 1% is the fissile U-235 (often 0.4-0.8%); and up to 1% is plutonium. Both can be recycled as fresh fuel, saving up to 30% of the natural uranium otherwise required. The materials potentially available for recycling (but locked up in stored used fuel) could conceivably run the US reactor fleet of about 100 GWe for almost 30 years with no new uranium input.

So far, almost 90,000 tonnes (of 290,000 t discharged) of used fuel from commercial power reactors has been reprocessed. Annual reprocessing capacity is now some 4000 tonnes per year for normal oxide fuels, but not all of it is operational.

Between now and 2030 some 400,000 tonnes of used fuel is expected to be generated worldwide, including 60,000 t in North America and 69,000 t in Europe.

World commercial reprocessing capacity1,2

(tonnes per year)
LWR fuel France, La Hague 1700
UK, Sellafield (THORP)
900
Russia, Ozersk (Mayak)
400
Japan (Rokkasho)
800*
Total LWR (approx) 3800
Other nuclear fuels UK, Sellafield (Magnox) 1500
India (PHWR, 4 plants)
330
Total other (approx) 1830
Total civil capacity
5630

* now expected to start operation in October 2012

Products of reprocessing

The composition of reprocessed uranium (RepU) depends on the initial enrichment and the time the fuel has been in the reactor, but it is mostly U-238. It will normally have less than 1% U-235 (typically about 0.5% U-235) and also smaller amounts of U-232 and U-236 created in the reactor. The U-232, though only in trace amounts, has daughter nuclides which are strong gamma-emitters, making the material difficult to handle. However, once in the reactor, U-232 is no problem (it captures a neutron and becomes fissile U-233). It is largely formed through alpha decay of Pu-236, and the concentration of it peaks after about 10 years of storage.

The U-236 isotope is a neutron absorber present in much larger amounts, typically 0.4% to 0.6% – more with higher burn-up – which means that if reprocessed uranium is used for fresh fuel in a conventional reactor it must be enriched significantly more (e.g. up to one-tenth more) than is required for natural uraniumb. Thus RepU from low burn-up fuel is more likely to be suitable for re-enrichment, while that from high burn-up fuel is best used for blending or MOX fuel fabrication.

The other minor uranium isotopes are U-233 (fissile), U-234 (from original ore, enriched with U-235, fertile), and U-237 (short half-life beta emitter). None of these affects the use of handling of the reprocessed uranium significantly. In the future, laser enrichment techniques may be able to remove these isotopes.

Reprocessed uranium (especially from earlier military reprocessing) may also be contaminated with traces of fission products and transuranics. This will affect its suitability for recycling either as blend material or via enrichment. Over 2002-06 USEC successfully cleaned up 7400 tonnes of technetium-contaminated uranium from the US Department of Energy.

Most of the separated uranium (RepU) remains in storage, though its conversion and re-enrichment (in UK, Russia and Netherlands) has been demonstrated, along with its re-use in fresh fuel. Some 16,000 tonnes of RepU from Magnox reactors in UK has been usedc to make about 1650 tonnes of enriched AGR fuel. In Belgium, France, Germany and Switzerland over 8000 tonnes of RepU has been recycled into nuclear power plants. In Japan the figure is over 335 tonnes in tests and in India about 250 t of RepU has been recycled into PHWRs. Allowing for impurities affecting both its treatment and use, RepU value has been assessed as about half that of natural uranium.

Plutonium from reprocessing will have an isotopic concentration determined by the fuel burn-up level. The higher the burn-up levels, the less value is the plutonium, due to increasing proportion of non-fissile isotopes and minor actinides, and depletion of fissile plutonium isotopesd. Whether this plutonium is separated on its own or with other actinides is a major policy issue relevant to reprocessing (see section on Reprocessing policies below).

Most of the separated plutonium is used almost immediately in mixed oxide (MOX) fuel. World MOX production capacity is currently around 200 tonnes per year, nearly all of which is in France (see page on Mixed Oxide (MOX) Fuel).

Inventory of separated recyclable materials worldwide3

Quantity (tonnes) Natural U equivalent (tonnes)
Plutonium from reprocessed fuel 320 60,000
Uranium from reprocessed fuel 45,000 50,000
Ex-military plutonium 70 15,000
Ex-military high-enriched uranium 230 70,000

History of reprocessing

A great deal of hydrometallurgical reprocessing has been going on since the 1940s, originally for military purposes, to recover plutonium for weapons (from low burn-up used fuel, which has been in a reactor for only a very few months). In the UK, metal fuel elements from the Magnox generation gas-cooled commercial reactors have been reprocessed at Sellafield for about 50 yearse. The 1500 t/yr Magnox reprocessing plant undertaking this has been successfully developed to keep abreast of evolving safety, hygiene and other regulatory standards. From 1969 to 1973 oxide fuels were also reprocessed, using part of the plant modified for the purpose, and the 900 t/yr Thermal Oxide Reprocessing Plant (THORP) at Sellafield was commissioned in 1994.

In the USA, no civil reprocessing plants are now operating, though three have been built. The first, a 300 t/yr plant at West Valley, New York, was operated successfully from 1966-72. However, escalating regulation required plant modifications which were deemed uneconomic, and the plant was shut down. The second was a 300 t/yr plant built at Morris, Illinois, incorporating new technology which, although proven on a pilot-scale, failed to work successfully in the production plant. It was declared inoperable in 1974. The third was a 1500 t/yr plant at Barnwell, South Carolina, which was aborted due to a 1977 change in government policy which ruled out all US civilian reprocessing as one facet of US non-proliferation policy. In all, the USA has over 250 plant-years of reprocessing operational experience, the vast majority being at government-operated defence plants since the 1940s.

In France a 400 t/yr reprocessing plant operated for metal fuels from gas-cooled reactors at Marcoule until 1997. At La Hague, reprocessing of oxide fuels has been done since 1976, and two 800 t/yr plants are now operating, with an overall capacity of 1700 t/yr.

Further Information

Notes

a. Used fuel from light water reactors (at normal US burn-up levels) contains approximately:

  • 95.6% uranium, over 98.5% of which is U-238 (the remainder consists of: trace amounts of U-232 and U-233; less than 0.02% U-234; 0.5-1.0% U-235; around 0.5% U-236; and around 0.001% U-237 – which accounts for nearly all of the activity)
  • 2.9% stable fission products
  • 0.9% plutonium
  • 0.3% caesium & strontium (fission products)
  • 0.1% iodine and technetium (fission products)
  • 0.1% other long-lived fission products
  • 0.1% minor actinides (americium, curium, neptunium)

[Back]

b. For the Dutch Borssele reactor which normally uses 4.4% enriched fuel, compensated enriched reprocessed uranium (c-ERU) is 4.6% enriched to compensate for U-236. [Back]

c. Since Magnox fuel was not enriched in the first place, this is actually known as Magnox depleted uranium (MDU), which assayed about 0.4% U-235. The MDU was converted to UF6, enriched to 0.7% at BNFL’s Capenhurst diffusion plant and then to 2.6% to 3.4% at Urenco’s centrifuge plant. Until the mid 1990s some 60% of all AGR fuel was made from MDU and it amounted to about 1650 tonnes of low enriched uranium. Although used Magnox fuel continues to be reprocessed, recycling of MDU was discontinued in 1996 due to economic factors. [Back]

d. At anything over about 20 GWday/t burn-up the plutonium is considered to be ‘reactor grade’ and significantly different from weapons grade material. Some figures for the Oskarshamn 3 nuclear unit: with 30 GWd/t burn-up, 69% Pu is fissile; 40 GWd/t, 61% fissile; 50 GWd/t, 55% fissile; and 60 GWD/t, 50% fissile. [Back]

e. See Note c above. [Back]

f. Minor actinides are americium and curium (95 & 96 in periodic table), sometimes also neptunium (93). The major actinides are plutonium (94) and uranium (92). [Back]

g. Atelier Alpha et Laboratoire pour les Analyses de Transuraniens et Etudes de retraitement, Alpha shop and laboratory for the analysis of transuranics and reprocessing studies. [Back]

h. Spallation is the process where nucleons are ejected from a heavy nucleus being hit by a high energy particle. In this case, a high-enery proton beam directed at a heavy target expels a number of spallation particles, including neutrons. [Back]

COGEMA La Hague site

The AREVA NC La Hague site is a nuclear fuel reprocessing plant of AREVA in La Hague on the French Cotentin Peninsula that currently has nearly half of the world’s light water reactor spent nuclear fuel reprocessing capacity. It has been in operation since 1976, and has a capacity of about 1700 tonnes per year. It produces plutonium which is then recycled into MOX fuel at the Marcoule site.

It treats spent nuclear fuel from FranceJapanGermanyBelgiumSwitzerlandItalySpain and the Netherlands. It processed 1100 tons in 2005. The non-renewable waste is eventually sent back to the user nation, as established under international law.

La Hague

Controversy surrounding radioactive releases

Greenpeace has been campaigning since 1997 for the shutdown of the site, which they claim dumps “one million litres of liquid radioactive waste per day” into the ocean; “the equivalent of 50 nuclear waste barrels”, claiming the radiation affects local beaches.[1][2][3] They have protested by creating roadblocks and chaining themselves to vehicles transporting materials to and from the site, demonstrating that they could determine which of the otherwise unmarked shipments were carrying plutonium by watching the facility for several weeks.[4][5][6] Eric Blanc, deputy director of the processing plant, says that although the plant does intentionally release radioactive material, the annual dose in the vicinity of the plant is less than 20 microsieverts per year, which is equivalent to the dose of solar radiation received during a transatlantic flight.[6] The AREVA NC website emphasizes that they are committed to keeping the dose below 30 microsieverts per year.[7]

http://en.wikipedia.org/wiki/COGEMA_La_Hague_site

Marcoule

From Wikipedia, the free encyclopedia
Marcoule
Marcoule is located in France

Location of Marcoule

Country France
Coordinates 44°8′36″N 4°42′34″ECoordinates44°8′36″N 4°42′34″E
Construction began 1952
Commission date January 7, 1956
Decommission date June 20, 1984
Operator(s) EDF/CEA
Reactor information
Reactors decom. 1 x 2 MW
2 x 38 MW
Power generation information
Net generation 11,346 GW·h
As of November 26, 2006

Marcoule (FrenchSite nucléaire de Marcoule) is located in the Chusclan and Codolet French communes, near Bagnols-sur-Cèze in the Gard department, which is in the touristic, wine and agricultural Côtes-du-Rhône region.

Since 1956, Marcoule is a gigantic site exploited by the atomic energy organization Commissariat à l’Énergie Atomique (CEA) and Areva NC. The first industrial and military plutonium experiments took place in Marcoule. Diversification of the site was started in the 1970s with the creation of the Phénix prototype fast breeder reactor, and is nowadays an important site for decommissioning nuclear facilities activities.

Since 1995, the MELOX factory produces MOX from a mix of uranium and plutonium oxides. MOX is used to recycle plutonium from nuclear fuel; this plutonium comes from the COGEMA La Hague site.

The ATelier Alpha et Laboratoires pour ANalyses, Transuraniens et Etudes de retraitement (ATALANTE) is a CEA laboratory investigating the issues of nuclear reprocessing of nuclear fuel and of radioactive waste.

Reactors

The site housed a number of the first generation French UNGG reactors, of which have all been shut down. Since then, it has also operated a pressurized water reactor that was used for the purpose of producing Tritium. Cooling for all of the plants has come from the Rhône river.

Unit Type Net power Total power Construction start Construction finish Commercial operation Shut down
Marcoule G1[1] UNGG reactor 2 MW 1955 07.01.1956 15.10.1968
Marcoule G2 UNGG reactor 38 MW 43 MW 01.03.1955 22.04.1959 22.04.1959 02.02.1980
Marcoule G3 UNGG reactor 38 MW 43 MW 01.03.1956 04.04.1960 27.05.1981 20.06.1984
Nuclear decommissioning

Example of decommissioning work underway.

The reactor pressure vessel being transported away from the site, which will be buried. Images courtesy of the NRC.

Nuclear decommissioning is the dismantling of a nuclear power plant and decontamination of the site to a state no longer requiring protection from radiation for the general public. The main difference from the dismantling of other power plants is the presence of radioactive material that requires special precautions.

Generally speaking, nuclear plants were designed for a life of about 30 years. Newer plants are designed for a 40 to 60-year operating life.

Decommissioning involves many administrative and technical actions. It includes all clean-up of radioactivity and progressive demolition of the plant. Once a facility is decommissioned, there should no longer be any danger of a radioactive accident or to any persons visiting it. After a facility has been completely decommissioned it is released from regulatory control, and the licensee of the plant no longer has responsibility for its nuclear safety.

Decommissioning options

The International Atomic Energy Agency has defined three options for decommissioning, the definitions of which have been internationally adopted:

  • Immediate Dismantling (or Early Site Release/Decon in the US): This option allows for the facility to be removed from regulatory control relatively soon after shutdown or termination of regulated activities. Usually, the final dismantling or decontamination activities begin within a few months or years, depending on the facility. Following removal from regulatory control, the site is then available for re-use.
  • Safe Enclosure (or Safestor(e) SAFSTOR): This option postpones the final removal of controls for a longer period, usually in the order of 40 to 60 years. The facility is placed into a safe storage configuration until the eventual dismantling and decontamination activities occur.
  • Entombment: This option entails placing the facility into a condition that will allow the remaining on-site radioactive material to remain on-site without the requirement of ever removing it totally. This option usually involves reducing the size of the area where the radioactive material is located and then encasing the facility in a long-lived structure such as concrete, that will last for a period of time to ensure the remaining radioactivity is no longer of concern.

[edit]Experience

A wide range of nuclear facilities has been decommissioned so far. This includes nuclear power plants (NPPs), research reactorsisotope production plants, particle accelerators, and uranium mines. The number of decommissioned power plants is small. There are companies specialized in nuclear decommissioning; the practice of decommissioning has turned into a profitable business. Decommissionning is very expensive. The current estimate by the United Kingdom‘s Nuclear Decommissioning Authority is that it will cost at least £70 billion to decommission the 19 existing United Kingdom nuclear sites; this takes no account of what will happen in the future. Also, due to the radioactivity in the reactor structure, decommissioning is a slow process which takes place in stages. The plans of the Nuclear Decommissioning Authority for decommissioning reactors have an average 50 year time frame. The long time frame makes reliable cost estimates extremely difficult. Excessive cost overruns are not uncommon even for projects done in a much shorter time frame.

Plutonium

Plutonium (play /plˈtniəm/ plooTOH-nee-əm) is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-white appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbonhalogensnitrogen and silicon. When exposed to moist air, it forms oxides and hydrides that expand the sample up to 70% in volume, which in turn flake off as a powder that can spontaneously ignite. It is also a radioactive poison that accumulates in bone marrow. These and other properties make the handling of plutonium extremely dangerous.

Plutonium is the heaviest primordial element (see also primordial nuclide), by virtue of its most stable isotopeplutonium-244, whose half-life of about 80 million years is just long enough for the element to be found in trace quantities in nature.[3]But plutonium is a regular byproduct of a reactor’s splitting uranium atoms in two. Some of the speeding subatomic particles of the fission process turn uranium into plutonium.[4]

The most important isotope of plutonium is plutonium-239, with a half-life of 24,100 years. Plutonium-239 is the isotope most useful for nuclear weapons. Plutonium-239 and 241 are fissile, meaning the nuclei of their atoms can break apart by being bombarded by slow moving thermal neutrons, releasing energy, gamma radiation and more neutrons. These can therefore sustain a nuclear chain reaction, leading to applications in nuclear weapons and nuclear reactors.

http://en.wikipedia.org/wiki/Plutonium

Rokkasho Reprocessing Plant

The Rokkasho Reprocessing Plant (六ヶ所村核燃料再処理施設 Rokkasho Kakunenryō Saishori Shisetsu?) is a nuclear reprocessing plant with an annual capacity of 800 tons of uranium or 8 tons of plutonium,[1] owned by Japan Nuclear Fuel Limited located in the village of Rokkasho in northeast Aomori PrefectureJapan approximately 17 miles (27 kilometers) north of the US Air Force’s Misawa Air Base. Since 1993 there has been US$ 20 billion invested in the project, nearly triple the original cost estimate.[2] It is currently[when?] undergoing test operations, separating a small amount of used nuclear fuel. It is the successor to a smaller reprocessing plant located in Tōkai, Ibaraki.

At the same site there will also be:

In 2010, the Rokkasho Reprocessing Plant consisted of 38 buildings on an area of 3,800,000 m². [1

Rokkasho Reprocessing Plant

Protests

In May 2006, an international awareness campaign about the dangers of the Rokkasho reprocessing plant, Stop Rokkasho,[3] was launched by musician Ryuichi SakamotoGreenpeace has opposed the Rokkasho Reprocessing Plant under a campaign called “Wings of Peace – No more Hiroshima Nagasaki”,[4] since 2002 and has launched a cyberaction[5] to stop the project. Consumers Union of Japan together with 596 organisations and groups participated in a parade on Jan. 27, 2008 in central Tokyo against the Rokkasho Reprocessing Plant.[6] Over 810,000 signatures were collected and handed in to the government on Jan. 28, 2008. Representatives of the protesters, which include fishery associations, consumer cooperatives and surfer groups, handed the petition to the Cabinet Office and the Ministry of Economy, Trade and Industry.

Seven consumer organisations have joined in this effort: Consumers Union of Japan, Seikatsu Club Consumer’s Co-operative Union, Daichi-o-Mamoru Kai, Green Consumer’s Co-operative Union, Consumer’s Co-operative Union “Kirari”, Consumer’s Co-operative Miyagi and Pal-system Co-operative Union.

Vitrification tests completed in November 2007. This consists of pouring high level dry waste reside along with molten glass into steel canisters.[7]

In June 2008, several scientists stated that the Rokkasho plant is sited directly above an active geological fault line that could produce a magnitude 8 earthquake. But Japan Nuclear Fuel Limited have stated that there was no reason to fear an earthquake of more than magnitude 6.5 at the site, and that the plant could withstand a 6.9 quake.[8][9]

[edit]2011 Tōhoku earthquake and tsunami

After the Tōhoku earthquake in March 2011, the plant ran on emergency power provided by backup diesel generators.[10] The emergency generators were not intended for long-term use.[11] Reportedly there are about 3,000 tons of highly radioactive used nuclear fuel stored in Rokkasho at current, that could overheat and catch fire if the cooling systems fail. Japanese radio reported on March 13 that 600 liters of water leaked at the Rokkasho spent fuel pool.[12] According to The New York Times, grid power was restored on March 14, 2011.[13]

The 7 April aftershock caused the loss of grid power again until the next day.[14

http://en.wikipedia.org/wiki/Rokkasho_Reprocessing_Plant