My Geiger counter is in the shop for maintenance.
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Nuclear Reactors 140 – Experiments on Nuclear Core Meltdowns
Corium is a name that was coined for the molten material that results when the fuel of a nuclear reactor melts down in a nuclear accident. It contains nuclear fuel, fission products, control rods, structural material, and chemical reaction products with air, water and steam. If the reactor core is breached, then there will also be molten concrete in the mix. There is currently a debate about the fate of the corium created during the nuclear disaster at Fukushima in March of 2011.
In order to better understand exactly what happens when a nuclear reactor core melts down, researchers have carried out experiments with substitutue materials like lead and glass. Tests at U.S. Brookhaven National Laboratories used varying levels of water as they dropped molten lead into a hole in the ground referred to as a “drywell.” Unlike lead, corium continues to generate heat on its own and so it remains liquid for a longer time. However, the behavior of molten lead can be useful in the study of corium.
Approximately ten ounces of lead were used in the tests, heated to seven hundred and fifty degrees Fahrenheit. The lead was placed in a modified tea strainer with used which had a more open mesh. The strainer was put on a ceramic pedestal. An aluminum tube was placed on top of the tea strainer to confine the lead like a reactor vessel. The holes in the tea strainer mimics the control rod holes in the bottom of a boiling water reactor.
Experiments in Japan with molten lead had similar results although the researchers did not use any water. The molten lead flowed through the mesh in the tea strainer and pooled in the terra cotta flower pot being used for a pedestal. When some of the molten lead flowed out through a hole in the flower pot, it created a lump of cooled lead that had the shape of the foot of an elephant. This shape was also seen in corium that oozed out of the containment vessel at Chernobyl.
At Fukushima, three of the reactors experienced a meltdown on March 11, 2011. The corium from the three reactors melted through the bottom of the reactrors during the first day of the disaster and is still sinking into the gound beneath the reactors. They think that the corium may be as much as thirty feet below the bottom of the reactors now. It is thought that there are three one hundred tons blobs of corium beneath Fukushima at around three thousands degrees Fahrenheit. Given the level of radioactivity and the ability of current technology, it will take thousands of years before the corium is cool enough for researders to find its exact location.
A great deal of cooling water has been pumped into the wreckage of the reactors to prevent more explosions. This water becomes contaminated with radioactive materials and has been being captured and stored. Recently, the volume of water has exceeded the ablity of the operators of Fukushima to decontominate and they have started pumping the contaminated water directly into the Pacific Ocean.
Three Mile Island Reactor after Meltdown:
1.
1. Inlet 2B
2. Inlet 1A
3. Cavity
4. Loose core debris
5. Crust
6. Previously molten material
7. Lower plenum debris
8. Possible region depleted in uranium
9. Ablated incore instrument guide
10. Hole in baffle plate
11. Coating of previously-molten material on bypass region interior surfaces
12. Upper grid dam
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Radiation News Roundup July 1, 2014
Fukushima has released up to 120 quadrillion Becquerels of radioactive cesium into North Pacific Ocean. enenews.com
Plutonium is being discharged into Pacific Ocean from the Fukushima nuclear power plant. enenews.com
Sellafield Ltd is putting in place a new kind of long-term commercial mechanism to secure specialist decommissioning services over a ten-year period. The work could be worth up to 2.6 billion. world-nuclear-news.org
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Geiger Readings for July 1, 2014
My Geiger counter is in the shop for maintenance.
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Nuclear Reactors 139 – Battle over the future of the United States Export – Import Bank
I have mentioned the economic aspects of nuclear power in many posts. I have also mentioned that nuclear nations such as France, Russia, Japan, China and the United States are trying to sell nuclear technology to other countries that do not have their own nuclear industries with a lot of these potential customers being Third World countries. Today, I am going to see how these two topics intertwine in the U.S.
The U.S. Export-Import bank exists to facilitate trade between U.S. companies and foreign customers. It provides financing assistance and credit transaction insurance. Supporters of the Ex-Im bank claim that the financing assistance provided by the bank can be essential to securing trade deals for U.S. companies that would have otherwise gone to the competition. Nowhere is this more apparent than in international trade in nuclear technology.
The Nuclear Energy Institute (NEI) bills itself as the “policy organization of the nuclear energy and technologies that participates in both the national and global policy-making process. NEI’s objective is to ensure the formation of policies that promote the beneficial uses of nuclear energies and technologies in the United States and around the world.”
The CEO of the NEI said a congressional hearing last Wednesday that ““A strong and reliable Ex-Im Bank will enable U.S. nuclear energy suppliers to compete for and win international nuclear energy tenders, add billions of dollars of U.S. exports and tens of thousands of American jobs and promote other U.S. national interests.” All that this requires is billions of dollars in direct and indirect government assistance.
The Director of International Supplier Relations at NEI recently reported that the estimate for the value of the nuclear industry over the next decade is seven hundred and forty billion dollars. There are seventy one new reactors being built and another one hundred and seventy two reactors in advanced planning stages. He said that “export credit agency support, which 60-plus countries offer, is nearly mandatory for foreign nuclear plant tenders.”
Critics of the Ex-Im bank complain that it is a government handout to wealthy corporations. Republican Congressmen have been threatening to defund the Ex-Im bank. I am generally not in favor of the U.S. taxpayer doing anything to help huge profitable corporations. With respect to the issue being discussed in this post, I am doubly against having the U.S. Ex-Im bank give any assistance to the export of any nuclear technology. The history of nuclear power is littered with cost overruns and cancelled projects. From a strictly economic point of view, these nuclear projects are poor investments.
Totally aside from whether nuclear power makes any sense in economic terms is the fact that a single accident at a single plant can heavily impact the whole global marketplace. Another Fukushima type incident and many more countries might stop using nuclear power. A major slow down in the nuclear industry would threaten the schedule and the cost of nuclear plant construction.
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Radiation News Roundup June 30, 2014
On 6/26/2014, TEPCO announced that they are going to start covering the sea bed of Fukushima plant port with concrete. fukushima-diary.com
Fukushima plutonium in playground about 40 miles from nuclear plant. enenews.com
First power has flowed from Argentina’s newest nuclear power reactor, the government said, supporting its goals for power generation diversity, fuel import reduction and ‘energy sovereignty’. world-nuclear-news.org
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Geiger Readings for June 30, 2014
My Gieger counter is in the shop for maintenance.
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Radiation News Roundup June 29, 2014
A Minamisoma citizen talked a public monitoring post shows the radiation level lower than a personal Geiger counter. fukushima-diary.com
Highest density of tritium measured from seawater of all of the crippled Fukushima reactors even outside of underground wall. fukushima-diary.com
Looks like Thorium Nuclear Energy has no future in USA. nuclear-news.net
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Geiger Readings for June 29, 2014
My Gieger counter is in the shop for maintenance.
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Radiation News Roundup June 28, 2014
