Blog
-
Geiger Readings for July 27, 2013
Ambient office = .101 microsieverts per hour
Ambient outside = .094 microsieverts per hour
Soil exposed to rain water = .093 microsieverts per hour
Mango from local produce store = .145 microsieverts per hour
Tap water = .120 microsieverts per hour
Filtered water = .100 microsieverts per hour
-
Thorium 8 – Thorium May Not Be the Answer
I have posted a number of articles about thorium. It is a radioactive element that some have suggested could replace uranium and plutonium in a new generation of reactors. Supporters say that thorium reactors would not be prone to meltdowns if cooling systems failed and they would not produce waste as dangerous as that produced by commercial reactors. India has huge reserves of thorium and has been working to develop commercial thorium reactors for decades. Other companies and countries have been actively researching and promoting thorium reactors for over fifty years. Recently there has been a backlash against the positive publicity in favor of thorium as the new and better source of nuclear power.
Thorium-232 has a half-life equal to the current estimated age of the universe – 14 billion years. Thorium is even more radiotoxic than uranium and plutonium. A given amount of radioactivity inhaled in the form of thorium compared to the same amount of radioactivity inhaled in the form uranium or plutonium results in a biological impact on bones over two hundred times as great. Thorium also produces daughter products that have half-lives of hundreds of thousands of years which means that spent thorium fuel must be stored for longer than spent uranium fuel.
Thorium cannot produce energy by itself. It must be mixed with weapons grade (ninety five percent pure) uranium or plutonium in order to produce energy. So even though thorium itself is safer than uranium or plutonium because it cannot be made into a bomb, in order to use it, bomb grade nuclear materials must be included. In addition, it would be easy to refine the uraium-235 in spent thorium fuel back to the level required for bomb production. Thorium reactor designs often utilize liquid sodium fluoride which is highly toxic and must be handled carefully. The high temperatures generated by experimental thorium reactors have damaged concrete structures containing the reactors.
Mining and milling thorium carries the same dangers as mining and milling uranium. Thorium breeder reactors have been built but they are not as efficient as uranium breeder reactors. In contrast to claims of more economical nuclear power from thorium, it turns out that the thorium fuel cycle is more complex and expensive than the uranium fuel cycle. In addition, the equipment and protective measures needed to handle thorium fuelare more expensive than what is required for the current types of nuclear fuel.
Thorium is much more abundant than uranium and would not pose a problem of supply. However, for all the other reasons detailed above, thorium is not the miracle fuel or the “green” nuclear alternative that it is purported to be. Despite aggressive promotion by trade associations such as the World Nuclear Association, thorium will never become a widely used nuclear fuel.
Diagram of thorium electron shells:
-
Geiger Readings for July 26, 2013
Ambient office = .079 microsieverts per hour
Ambient outside = .081 microsieverts per hour
Soil exposed to rain water = .087 microsieverts per hour
White peach from local grocery store = .183 microsieverts per hour
Tap water = .079 microsieverts per hour
Filtered water = .065 microsieverts per hour
-
Nuclear Industry and International Politics
Nuclear energy has always been closely connected to national and international politics. The promise of nuclear power was sold in the United States and the Soviet Union because their governments wanted to spend more money on nuclear weapons development than their people were willing to support. Promising cheap energy from nuclear reactors was one way of pouring ever more money into nuclear research and development. With the end of the Cold War and the nuclear disarmament treaties, a lot of that impetus was lost. Regional and global international organizations were created to police the use of nuclear reactors to generate electricity. The world is currently focused on preventing Iran from creating nuclear weapons and restraining North Korea from further development and testing of nuclear weapons.
In the early 2000s, there was talk of a “nuclear renaissance.” Nuclear power was put forward as a solution to the global warming caused by the burning of fossil fuels. Many old reactor reaching the end of their original licensed lifespans of forty years were relicensed for another twenty years. Rosy predictions were made about how inexpensive and reliable the new generation of reactors would be.
Then reality set in with the Fukushima disaster in Japan. The world recoiled in shock and horror as melting nuclear reactor cores threatened the whole world with fallout. Even two years later, radioactive water continues to flow into the Pacific Ocean threaten the food chain. All of Japans nuclear reactors were shut down and all but a few are still offline. Germany decided to end the use of nuclear power. Other countries took a hard look at nuclear power and found that new construction was often far over budget and behind schedule. Old reactors that failed to compete with cheap natural gas were shut down. Other old reactors were simply too expensive to repair and upgrade and they were shut down.
But the nuclear industry is not going to go away quietly. The new Japanese Prime Minister Abe is touring the world to sell Japan’s nuclear technology. Russia is very active in selling its nuclear technology to other countries. They have even developed a nuclear reactor barge that can be towed anywhere. In the United States, lobbying groups are pressuring the President to strongly advocate for domestic nuclear power. France’s national nuclear company is also seeking contracts in other countries. Although Germany has vetoed nuclear subsidies in the European Union, the Dutch and other members are finding ways around the prohibition to funnel money to the nuclear industry. I recently received an invitation to a U.S. nuclear contractor conference where they were going to discuss ways to restore confidence in the industry by bringing projects in on time and in budget.
Unfortunately for the nuclear industry, they are not as powerful as the fossil fuel or bank lobby. Also, Fukushima was a disaster for their reputation. And, finally, there is no longer the close link between the domestic nuclear industry and the defense industry that existed during the Cold War. I am afraid that their nuclear renaissance is going to more of a nuclear bust.
-
Geiger Readings for July 25, 2013
Ambient office = .123 microsieverts per hour
Ambient outside = .134 microsieverts per hour
Soil exposed to rain water = .126 microsieverts per hour
Strawberry from local grocery store = .157 microsieverts per hour
Tap water = .065 microsieverts per hour
Filtered water = .060 microsieverts per hour
-
Nuclear Accidents 18 – Update on Fukushima Melted Cores
I have posted many blog entries and links that dealt with the ongoing situation at the site of the Fukushima nuclear disaster in Japan. There has been some progress in removing some debris and analyzing what has happened and what is happening. There are still many important unanswered questions. Critics continue to accuse TEPCO of not being forthcoming with complete information about what is occurring at Fukushima.
During the disaster in March of 2011, the cores of the Unit One, Two and Three reactors melted down into the Earth under the nuclear power plant. It is unclear exactly where they are and what state they are in but there have been emissions of steam recently that indicates that something underground is still very hot. Large volumes of water are still being pumped underground in the vicinity of the three melted cores to cool them. There is some evidence that the contaminated cooling water is draining into the Pacific Ocean. Various schemes have been proposed to prevent this such as building an underground wall between the reactor cores and the ocean.
Radioactive water known as tritium has been detected coming from the area of the cores. Tritium emits beta particles (energetic electrons) that can pose a danger to the health of any living creature that consumes water containing tritium. Beta particles can damage DNA and cause cancer. The tritium levels in the ocean off Fukushima have recently been rising. With a half-life of 12 years, the tritium from Fukushima can be carried across the ocean to North America. Evaporating into the atmosphere and raining down on the West Coast of the United States, the tritium could enter the food supply and threaten public health.
Even more problematic is the possibility of reactions that could generate sufficient hydrogen gas to trigger an explosion more powerful than the one that demolished the Unit Three reactor building and severely damaged the Unit Four reactor building. The Unit Four building has been reinforced but a huge explosion nearby might empty the water in the spent fuel pool on the fourth floor of the Unit Four building and ignite the spent fuel rods in the pool. This would inject a huge amount of radioactive materials into the atmosphere which would be carried around the entire northern hemisphere by air currents.
While it is still not clear what will be required to actually clean up and decommission the Fukushima site, estimates run to decades and hundreds of billions of dollars. There is a furious debate going on right now in Japan with respect to restarting their fifty four reactors. The new Japanese Prime Minister is traveling around the planet trying to promote the sale of Japanese nuclear reactor technology. Viet Nam and Japan are currently discussing the construction of a new reactor by the Japanese in Viet Nam. I think that it may be a trifle premature for Japan to be exporting their nuclear technology until they clean up Fukushima.
-
Radiation News Roundup for July 24, 2013
Crowd-sourced data provides a high-res view of radiation levels in Japan. technologyreview.com
Entirely possible leaking nuclear material from Fukushima is going to U.S. and Canada. enenews.com
A new nuclear cooperation agreement struck between South Africa and the European Union will support joint nuclear research and could help open access to South Africa’s uranium resources. world-nuclear-news.org
