Sentences with phrase «water reactor cooling»

Unlike the TerraPower concept, the mPower reactor relies on an advanced light water reactor cooling technology that NRC staff have deeply examined for decades.

Not exact matches

Baffle bolts hold in place baffle plates, which channel cooling water to the reactor core.

However, the power plant needs a permit from New York State to use Hudson River water to cool its reactor cores.

Indian Point needs state permits to use water from the Hudson River to cool its reactors and then discharge the warm water back into the river.

Entergy countered by proposing a much cheaper wedge wire screen system that prevents fish from getting sucked into the water intake system used to cool the nuclear reactors.

But community groups are concerned about the potential for accidents, and environmentalists about the toll nuclear takes on water resources and the wildlife killed when reactors use river or lake water for cooling — particularly at Indian Point, less than 30 miles north of New York City on the Hudson River.

Each day, some two billion gallons of water are pumped from Long Island Sound into the Millstone Power Station in Waterford, Conn. — that state's only nuclear power plant — and used to help cool systems and support the station's two operating reactors.

In fact, throughout the first week of the Fukushima crisis, emergency workers tried to figure out a way to open up a larger hole in the Unit 2 reactor building, which had not suffered an explosion, to allow better access to inject cooling water without creating the kind of spark that might cause another hydrogen blast.

Much as what unfolded during the crisis in Japan, the computer modeling suggested that fuel in one of the two reactors on the Peach Bottom site would begin to melt as soon as nine hours after a loss of cooling water flow.

In the event of a breakdown of pumps that supply the reactor with fresh cooling water, the torus design is supposed to provide additional cooling.

Burnell referred to the water reservoir above the shield building that floods the reactor containment area if normal reactor cooling systems fail.

And there is some somewhat alarming language that talks about, and I'll just quote «the IAEA tells us the earthquake triggered a power failure at the Fukushima Daiichi unit 2 nuclear power plant, and then when a backup generator also failed, the cooling system was unable to supply water to cool the reactor.

No electricity to run pumps to add cooling water to the melting down reactors.

The meltdown started when water to cool the reactors fell to dangerously low levels four hours after the fourth - largest recorded earthquake rattled the Fukushima Daiichi nuclear power plant.

Another issue for critics is whether the water delivered from the elevated reservoir in an emergency would continue to cool the reactor if there were a sustained loss of power for emergency pumps.

The explosions tore open reactor buildings, damaging the 12 - meter - deep pools where used nuclear fuel is kept cool, potentially setting off another meltdown in the fuel there as the surrounding water drained away or boiled off.

As NRC staff noted during the Fukushima emergency, when there was concern that the spent - fuel pool at Unit 4 may have lost its cooling water as well as been damaged by the reactor building explosion, adding cold water to already hot fuel can create a problem in its own right.

These reactors have the intriguing feature that the water used to cool the core and run the generating turbine is also essential to maintaining a nuclear chain reaction.

There are some 50 modular designs being developed globally, and while many are traditional light water reactors, which use water to cool the reactor core, others gain efficiency by using coolants such as gas, which allow reactors to reach higher temperatures.

The NRC investigators reported: • The plant had a single diesel - driven pump to provide emergency cooling water to a single reactor in case an earthquake cut off normal water flow.

External tanks hold enough additional water to cool the reactor for two weeks in the event of a loss of power as well.

The plant's operator, Tokyo Electric Power Co. (TEPCO), responded by cooling the reactors with water, which continues today.

Water is being deliberately circulated through each reactor every day to cool the fuel within — but the plant lies on a slope, and water from precipitation keeps flowing into the buildings as Water is being deliberately circulated through each reactor every day to cool the fuel within — but the plant lies on a slope, and water from precipitation keeps flowing into the buildings as water from precipitation keeps flowing into the buildings as well.

On 14 March, engineers decided they had to take further steps to cool the reactor vessel down, and so began pumping sea water into the vessel along with boron, an element that dampens nuclear reactions by soaking up the neutrons which drive them.

In addition to its unique fuel cycle, the TerraPower design employs a high - temperature, liquid metal core cooling technology suited to a breeder reactor with «fast» neutron activity, rather than today's predominant reactors whose water cooling systems slow neutrons.

Alabama also objected, worried about another species: nuclear power plants, which use enormous quantities of water, usually drawn from rivers and lakes, to cool their big reactors.

• Workers have connected a cable to feed power to two of the crippled reactors, with the hope of restarting the water pumps that cool the cores.

Jaczko, chairman of the Nuclear Regulatory Commission, said his staff in Tokyo had been told by Japanese utility officials that cooling water that normally covers spent fuel was nearly or totally gone from an uncovered concrete pool above reactor Unit 4.

The problem appears to be not that the reactors might overheat because of the lack of water but that the depleted rivers might overheat, creating ecological havoc, when the water returns to them after cooling the reactors.

As of 10 P.M. local time on Thursday, the JAIF listed the following status of the six Fukushima Daiichi reactors: • Buildings around reactor Nos. 1, 3 and 4 were «severely damaged»; the building housing reactor No. 2 was «slightly damaged»; • Cooling was not working for reactor Nos. 1, or 3; • Water levels were covering more than half of the fuel in reactor No. 2; reactor Nos. 1 and 3 water levels were covering only about half of the Water levels were covering more than half of the fuel in reactor No. 2; reactor Nos. 1 and 3 water levels were covering only about half of the water levels were covering only about half of the fuel.

China has or is building heavy - water reactors from Canada, «evolutionary» pressurized - water reactors from France, pebble - bed reactors tested in South Africa, and even is working on reactors that would use molten salt for cooling and thorium for fuel.

Novel designs with alternative cooling fluids other than water, such as Transatomic Power's molten salt — cooled reactor or the liquid lead — bismuth design from Hyperion Power, are in development.

And whether or not the 50 tons of water dumped on reactor No. 3 was enough to temporarily cool the spent fuel pool, the efforts will need to continue to avoid a significant release of radiation.

The most damaged Daiichi reactor, number 3, contains about 90 tons of fuel, and the storage pool above reactor 4, which the Nuclear Regulatory Commission's (NRC's) Gregory Jaczko reported yesterday had lost its cooling water, contains 135 tons of spent fuel.

That hydrogen buildup was the result of hot steam coming into contact with overheated nuclear fuel rods covered by a cladding of zirconium alloy, or «zircaloy» — the material used as fuel - rod cladding in all water - cooled nuclear reactors, which constitute more than 90 percent of the world's power reactors.

As the recent meltdown in Fukushima showed, the design of these reactors» systems, such as the donut - shaped «suppression pool» of water meant to cool the reactor in a crisis, showed flaws — flaws identified by regulators decades ago.

As well, Diablo Canyon's on - site desalination plant, which provides fresh water to cool the reactors themselves, has two reserve pools of 2.5 million gallons each, which are above the reactors and could be tapped if the plant goes down.

One, the colder the cooling water entering a reactor, the more efficient the production of electricity.

At present, the Tokyo Electric Power Company (Tepco), which runs the plant, redirects the water over the reactor cores to keep them cool.

But those reactors» spent fuel pools are benefiting from a diesel generator that is still working to keep cooling water in place, according to World Nuclear News, though temperatures are beginning to rise in these pools as well.

At about 4 A.M. local time, the main pumps feeding cooling water into Unit 2 failed and, due to confusion amidst the klaxon of alarms and flashing warning lights, the men operating the reactor made the situation worse when they mistakenly thought there was too much water in the core and shut off emergency pumps, thereby reducing further the amount of coolant reaching the reactor.

Some of the workers will be needed to maintain the system that cools damaged fuel rods in the reactors with thousands of tonnes (1 tonne = 1.102 metric tons) of water every day.

Light water - cooled graphite - moderated reactors Fuelled by low - enriched uranium oxide, these reactors use graphite as a moderator and water to cool the core.

But the fuel still inside the reactors must be cooled with water to prevent it overheating and releasing radioactive gases.

Although these pumps did not provide cooling water directly to the reactor, they supported other essential equipment, and in this case, other pumps were working.

Spent fuel assemblies that have been removed relatively recently from reactors are kept in deep pools of water to cool them and shield the radiation they emit.

All of the remaining reactors, however, will remain offline until they have been upgraded to meet extended safety requirements, such such as the provision of alternative power supplies, multiple sources of cooling water, back - up control rooms and venting to prevent hydrogen escape.

The water around the reactor core serves as three things: a neutron moderator, meaning it slows down the fast neutrons released during fission, which then sustain the chain reaction; a cooling agent; and a radiation shield.

RIAR's reactors provide a full range of capabilities to test fuel and materials of all types of existing power reactors as well as advanced and innovative ones: water - cooled thermal reactors, including those with boiling and pressurized water, gas - cooled, fast and other types of reactors.

The high - flux research reactor SM - 3 is a vessel - type water - cooled reactor operated at intermediate neutrons.