Sentences with phrase «damaged reactor»

Then workers removed debris from atop the damaged reactor building.

Then the task force followed with a dozen major recommendations, some of which would order nuclear plant operators to strengthen defenses against extreme flooding or earthquakes when necessary and to harden vents that would carry away explosive hydrogen gas from damaged reactor cores in the two types of reactors at the Fukushima Daiichi plant.

The top U.S. nuclear regulator, Gregory Jaczko, gave a dire assessment of Japan's nuclear crisis yesterday, saying that lethal radiation from uncovered spent fuel above one of the reactors could force emergency workers to abandon their fight to prevent meltdowns of damaged reactor cores at the Fukushima Daiichi plant.

The explosion may have damaged the reactor pressure vessel, perhaps holing it, leading to a partial meltdown and leak of the fuel inside.

The cable trench there contains much more radiation than those in the other three damaged reactor units.

It was previously thought that only volatile, gaseous radionuclides such as caesium and iodine were released from the damaged reactors.

In the early days of the crisis, engineers were desperate to learn about the damaged reactors» cores and the radiation levels inside the buildings, data that robots should have been able to provide.

«Doomsday» scenarios But the resulting radiation could be so high, «it would be almost impossible to get anyone in there,» to continue supplying water to the damaged reactors, he said.

Leaks of hydrogen from damaged reactors at units Nos. 1 and 3 is blamed for explosions at the tops of the outer, secondary containment structures, and an explosion within the No. 2 primary containment structure.

When used on tungsten surfaces in fusion devices, lithium can reduce periodic instabilities in plasma that can damage the reactor walls, scientists have found.

Engineers use a flying drone to peer into the damaged reactors at the Fukushima Daiichi nuclear power plant.

This is the latest headline hype in coverage of efforts to control the damaged reactors at the Fukushima nuclear power complex in northern Japan.

Ongoing challenges with managing the damaged reactors — and concerns about radiation releases — mean the Fukushima disaster is far from over.

Not exact matches

«They still went into a pitch black, badly damaged basement beneath a molten reactor core that was slowly burning its way down to them,» he said.

TOKYO (AP)-- About 1,400 people filed a joint lawsuit Thursday against three companies that manufactured reactors at Japan's Fukushima Dai - ichi nuclear plant, saying they should be financially liable for damage caused by their 2011 meltdowns.

«So reactor 3 should not start up again until the Nuclear Regulatory Commission has done a full public evaluation of the cause of these damaged bolts.»

According to the department's evaluation, one nuclear reactor has a relatively high risk of damage from an earthquake.

Officials said the decision to change the plant's nuclear safety level was due to cumulative radiation releases since the earthquake wreaked serious damage to the reactors, rather than a sudden deterioration in conditions.

The NRC reportedly ranked Indian Point as the reactor with the highest risk of earthquake damage in the United States, even higher than the twin reactors in California's quake zone, reports CBS 2's Marcia Kramer.

I brought up the MSNBC report that deemed one of the three reactors at the Hudson River nuclear power plant 24 miles from NYC (or 34 miles from Midtown, depending on how you're measuring), the most at risk in the nation of earthquake damage.

In the wake of the Japan crisis and an MSNBC report that one of the Indian Point reactors is more at risk for earthquake damage than any other in the nation — a claim refuted by the NRC — Cuomo called for a full safety review of the plant.

«The Indian Point nuclear power plant, which sits within two miles of two intersecting fault lines has the highest risk of an earthquake causing its reactors core damage in the United States,» Carlucci said in a statement.

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.

Uranium and other radioactive materials, such as caesium and technetium, have been found in tiny particles released from the damaged Fukushima Daiichi nuclear reactors.

Understanding the nature of radiation damage in materials is of paramount importance for controlling the safety of nuclear reactors, using ion implantation in semiconductor technology, and designing reliable devices in space.

The reactors along Japan's Pacific coast suffered no serious damage from the earthquake, even though its magnitude exceeded the worst - case scenarios assumed in their designs.

The Nuclear Regulatory Commission says that it considers the 104 U.S. nuclear plants to be secure, but the evidence from Japan's devastating reactor damage would be the basis for a new review

In a severe accident at Indian Point, where it was crucial to relieve pressure inside the reactor containment, high pressures could damage equipment required to carry out the venting and «potentially prevent containment depressurization,» the NRC said.

The rest of this special News & Analysis section examines what we have learned about radiation risks from previous exposures (p. 1504), improvements in safety since the boiling water designs at Fukushima (p. 1506), what to do with the wrecked reactors (p. 1507), and damage to research facilities from the earthquake (p. 1509).

Tsunami - damaged nuclear reactors, Twitter - fueled political uprisings, a possible violation of Einsteinian physics — these and other highlights defined this year in science and technology

Applications: The goal is protecting nuclear reactors, dams, airports, government offices, and other sensitive and essential structures from earthquake damage.

What remains unclear is how much of the nuclear fuel at any of the three Fukushima Daiichi reactors has melted down, though TEPCO has announced that the fuel is likely damaged in all three reactors that were operating there at the time of the earthquake.

However, the reaction also produces high - energy neutrons, which would damage whatever vessel the fusion reactor is in and render anything around them radioactive.

The NRC analysis found that a fire in a spent - fuel pool at an average nuclear reactor site would cause $ 125 billion in damages, while expedited transfer of spent fuel to dry casks could reduce radioactive releases from pool fires by 99 percent.

Compared to other reactors, if you look at NRC studies, according to calculations, it has a relatively low core - damage frequency.

The plant's best hope may be restoration of outside power, which could allow workers to restart cooling operations for the reactors and the cooling pools, provided they have not been too severely damaged.

Radiation levels are too high for an inspection, but the damage is thought to have been to a doughnut - shaped tank directly beneath the reactor vessel.

Whereas various participants discussed the policy ramifications of the crisis, physicist Ken Bergeron provided most of the information regarding the actual damage to the reactor.

Another issue Motojima has had to grapple with is whether or not to add another set of magnetic coils to the interior walls of the reactor to help control disturbances in the plasma called edge - localized modes (ELMs) that can damage the inside of the plasma vessel.

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 fuel.

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.

But the greatest damage to the complex, and the greatest release of radiation, may have been caused by explosions of hydrogen gas that built up inside some of the reactors.

The buildings housing reactors Nos. 1, 2, 3 and 4 have all suffered damage from hydrogen explosions, caused by the high - temperature, high - speed interaction of fuel rods and steam.

However, four decades of analysis and experience have demonstrated that reactor core - damage risks are dominated by «beyond - design - basis events,» the report says.

Three reactors — Units 1, 2, and 3 — sustained severe core damage, and three reactor buildings — Units 1, 3, and 4 — were damaged by hydrogen explosions.

Nuclear Elec - tric, which regularly assesses the level of neutron damage at its stations by monitoring the condition of samples of construction materials placed in the reactor, decided to shut down the plant's two reactors to investigate what was happening more thoroughly.

If unchecked, a meltdown can send superheated fuel through the steel and concrete that surrounds it, damaging or destroying the reactor and releasing extreme levels of radiation into the environment.

The embattled utility remains in charge of the work to dismantle the damaged Fukushima reactors, a government - subsidized job expected to take 30 years or more.

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.