fuel rods

The fuel rods began to boil off the remaining water, allowing water levels to drop and leaving the fuel at least partially exposed.

The threat comes within days of Pyongyang saying it had begun reprocessing spent fuel rods at its Yongbyon nuclear plant.

Some experts theorize the plutonium might have come from pools at the facility that hold spent fuel rods.

Some of the salt might be settling to the bottom of the reactor vessel rather than sticking to the fuel rods.

The workers at the Fukushima Daiichi nuclear plant are trying to cool down the fuel rods inside the nuclear reactors.

It had not been emitted directly by fuel rods, which would be far more virulent, they said.

He said: "The state of the reactor core can not confirm, however, can not conclude that there is no dissolution of nuclear fuel rods. "

A sudden drop in cooling water levels when a pump ran out of fuel had fully exposed the fuel rods for a time, an official said.

The big question is how much of that salt is still mixed with water and how much now forms a crust on the uranium fuel rods.

Yes, they said, uranium fuel rods in the tsunami-hit facility's reactors might have been damaged after cooling systems failed.

in return it would receive within a year more highly enriched (to 20%) fuel rods for its ageing medical-research reactor.

Evaporation in the cooling pools used for spent fuel rods led to the detonation of stored weapons-grade plutonium and uranium.

The reactor core is the main part of the reactor, housing the active fuel rods that provide the heat that generates power at the plant.

These fuel rods are then put together to form larger packages, and a number of these packages are then put into the reactor.

Unit 2 of the nuclear fuel rods of about 2. 7 meters above the surface, exposing the length of the almost half of the nuclear fuel rods.

These pools are used to warehouse spent fuel rods, which are no longer being used but remain highly radioactive and must also be cooled.

"If the pumping system is down there won't be enough pressure or water inside to cool the fuel rods down, " he said.

The fuel rods could still get hot enough to damage their cladding and release radioactive particles into the air.

With the cooling system down, the water that surrounds the nuclear fuel rods began to burn off.

Fuel rods in use as well as spent rods in cooling pools began to heat up, triggering fires and explosions.

Fire trucks, riot police water cannon and helicopters were all deployed to cool nuclear fuel rods at the plant, 240km north of Tokyo.

At units 1 and 3, fuel rods were left exposed for long enough to allow at least some melting, experts believe.

But Salehi announced the end of August, due to hot weather Bushehr, Iran for security reasons, decided to postpone the loading of fuel rods.

The operation was intended to help cool the reactors and also to replenish water in a storage pond with spent fuel rods.

Fuel assembly is a cylindrical pellets made of uranium dioxide fuel rods, and then assembled according to a certain order.

This will cause a meltdown, meaning the fuel rods melt to the bottom of the steel pressure vessel.

A meltdown occurs when nuclear fuel rods cannot be cooled, thus melting the reactor core and causing a release of radioactivity.

The material would then have been sent on to France to be turned into fuel rods.

Fuel rods that were producing fission have cooled substantially since the reactors shut down.

In a so-called "nuclear swap deal" Iran would export its low-enriched uranium abroad for further enrichment and conversion into fuel rods.

The worst contamination so far has come mainly from fires in ponds where spent fuel rods are stored.

Mixed oxide fuel rods are partly made of plutonium. These fuel rods are partly exposed.

At some stage during this venting process, the water level may have dropped below the top of the fuel rods.

They say the fuel rods were almost completely exposed - raising fears of a further catastrophe.

The blue circle oxide films on fuel rods near the welded zone by electron beam (EB) welding were formed after corrosion tests.

If the water boils away, the stored fuel rods can become exposed to air leading to the risk of hydrogen formation and radioactive release.

Japanese army helicopters on Thursday dumped water on the reactors to try to cool overheated fuel rods.

are still radioactive and potentially as hot and dangerous as the fuel rods inside the reactors if not kept submerged in water.

Unit 2 nuclear reactor cooling water, the water level was 14 pm sharp decline, resulting in complete nuclear fuel rods out of the water.

Officials worry that spent fuel rods stored at the site could heat up and release radioactive material.

This process decreased the temperature of the fuel rods to a non-damaging level.

Then, hours later, a new problem sent the water levels plummeting again and left the fuel rods fully exposed.

The IAEA wants Iran to send most of its uranium stockpile to Russia and France to boost it to 20 percent and turn it into fuel rods.

A partial meltdown can occur when radioactive fuel rods, which normally are covered in water, remain partially uncovered for too long.

The melted fuel rods simply aren't hot enough to melt steel or concrete.

Japan's national news agency, Kyodo, said 33 percent of the fuel rods at a second reactor were also damaged.

Previously, officials had theorized that exposed fuel rods may have partially melted in the days following the quake.

Japanese experts say the fuel rods inside the reactor were fully exposed to the air and melted.

If the fuel rods became damaged they would release radioactive material into the remaining coolant.

The spokesman said that his nation had "reprocessed more than one-third of our spent nuclear fuel rods. "

Mixedoutsideoxide fuel rods are partly made of plutonium.

Iran is to return the spent fuel rods for reprocessing in Russia under international safeguards.

Simulation of the REP fuel rods thermal behaviour during transient conditions.

Mixedupsideoxide fuel rods are partly made of plutonium.

On Saturday, specialists from both countries loaded uranium packed fuel rods into the reactor.

These fuel rods are partly exposed. Without water, they will continue to heat up and possibly release a large amount of radiation.

Overheating of fuel rods earlier in the crisis likely caused the material coating the fuel rods to melt, producing hydrogen.

Experts had worried that the fuel rods were exposed, making more likely to heat up.

Mixed oxide (MOX) fuel rods, partly composed of especially toxic plutonium are partially exposed.

Does Iran expect to get the 20% enriched fuel rods from another source, while its own uranium is under Turkish guard?

Reactor 4 had been shut down before the quake for maintenance, but its spent nuclear fuel rods are still stored on the site.

A portion of the No. 1 reactor's fuel rods has become exposed due to a failure of the cooling system.

Japanese workers are scrambling to control a nuclear plant after a fire that may have burned several fuel rods.

By 2015, will start from 1 to 4 units of fuel rods out of the pool, after the reactor containment of damage to repair and filled with water.

These fuel rods are then put together to form assemblies, of which several hundred make up the reactor core.

Damaged fuel rods in three of the facility's six reactors require constant cooling to prevent them from heating up again.

The reactors are hidden under those red circles. On the left are the fuel rods.

If the coolant continues to evaporate, the water level can fall below the level of the fuel rods, exposing them.

And until it does, shooting spent fuel rods into space remains a very dangerous propositionindeed.

China is building a repository for high-level nuclear waste, like conventional fuel rods, in the country's arid west.

The concern focused in particular on overheating of the spent fuel rods .

The targets were cooling ponds situated above the reactors, which store fuel rods.

But on Monday, water levels dropped, leaving fuel rods almost entirely exposed.

"If so, " Mr. LaVerne said in an interview, "you have an explosive mixture being formed near the fuel rods. "

The most dangerous uranium at the plant is not in the reactor cores but in the 11, 195 spent fuel rods stored at the site.

Inside those fuel rods is sealed the actual fuel, little ceramic pellets of uranium oxide.

The fuel rods then assembled in clusters to form the fuel assemblies for loading into the reactor core.

They switched to military fire engines to dowse the reactors and the pools of spent fuel rods beside them.

They switched to military fire engines to douse the reactors and the pools of spent fuel rods beside them.

The DPRK will restart the reprocessing of the used fuel rods, he added.

Japanese technicians have attached power cables to all six reactors and started a pump at one to cool overheating nuclear fuel rods.

Reprocessing the remaining spent fuel rods at Yongbyon would give it one more bomb.

The pellets of nuclear fuel are encased in hard alloys based on zirconium (which lets neutrons pass freely through), to make fuel rods.

By contrast, at Tepco and other utilities, it's common to temporarily remove all the fuel rods.

The reactor they were studying operated on fuel rods.

A separate storage pool for spent fuel rods also is drawing the attention of some Tepco and safety officials.

The Fukushima Daiichi plant has seven pools dedicated to spent fuel rods.

If the core gets too hot, the fuel rods can crack and release radioactive gases.

Zhe is the Tokyo Electric Power Company for the first time acknowledged solubilized liquid fuel rods.

At reactors No. 5 and No. 6, which were less severely damaged, a rise in temperature in the pools for spent fuel rods had worried officials.

In all three cases, the problems have arisen after levels of water needed to cool reactor fuel rods fell.

The fuel rods' zirconium casings then begin to react with the steam.

Army helicopters dumped tonnes of water to try to prevent a meltdown of fuel rods.

The fuel rods are bundled together in the core of the reactor.

The same risks, the Union of Concerned Scientists pointed out, exist in Reactors 5 and 6, which are also offline and store spent fuel rods.

If fuel rods or spent fuel gets too hot, it can explode or otherwise send radioactive matter into the air.

The storage pools, which contain used fuel rods, also need a constant supply of water.

safe to remove the fuel rods of tool development more difficult.

Examination of spent pressurized water reactor fuel rods after 15 years in dry storage.

Even when they are not in use, the nuclear fuel rods remain very hot for weeks or months.

The nuclear fuel is encased in hard alloys to construct fuel rods.

Liquid-metal-bonded gap for light water reactor fuel rods.

Since the quake hit, fuel rods in the cores of reactor 1, 2 and 3 have overheated because of a lack of cooling water.

For solution of heat transfer equation in fuel rods, the implicit scheme of through counting in combination with method of running is used.

Under the pact, Russia will supply the fuel for Bushehr and then take back the spent fuel rods.

The blast exposed the spent fuel rods stored there.

If the crusts are thick enough, they can block water from circulating between the fuel rods.

Work at the plant continued on Sunday to improve the water-pumping system that is attempting to keep the reactor and spent fuel rods cool.

There is a second type of radioactive material created outside the fuel rods.

It is critical that the spent fuel rods remain covered in water, otherwise they can emit lethal doses of radioactivity.

Of greatest concern are the spent fuel rods stored at reactor Nos. 3 and 4.

These spontaneous fissions are what keep the fuel rods hot even when the core is shut down.

Pyongyang reportedly also offered to negotiate the sale of 12, 000 nuclear fuel rods.

This type of waste makes up just 0. 3% of Britain's total volume of nuclear waste, which is mostly waste from spent fuel rods.

Fuel rods and the entire plant will be checked for potential damage. This will take about 4-5 years.

Unit 4 cooling pool a total of 1, 331 fuel rods, after the earthquake, once the water temperature rises to boiling.

Apart from America, which supplied the Tehran reactor in the 1960s, only France and Argentina can make the right fuel rods.

Unit 1 out of water because the fuel rods, there is also the possibility of melt-down.

And until 2022, for Unit 1 to 3 of reactor fuel rods melted recovery.

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