Blog
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Geiger Readings for April 8, 2014
Ambient office = 65 nanosieverts per hourAmbient outside = 48 nanosieverts per hourSoil exposed to rain water = 64 nanosieverts per hourRedleaf lettuce from Central Market = 62 nanosieverts per hourTap water = 80 nanosieverts per hourFiltered water = 71 nanosieverts per hour -
Nuclear Reactors 115 – Upgrading U.S. Nuclear Power Reactors for Greater Earthquake Resistance
One of the most frightening dangers that nuclear reactors face is the possibility of a nearby earthquake. Containment domes could crack, reactor cores could be severely damaged and melt down, spent fuel pools could be emptied and expose fuel rods to the open air, etc. The ability of the design of a particular reactor to withstand possible earthquakes in the vicinity is very important with respect to licensing the site of a nuclear reactor.
When the Diablo Canyon nuclear power plant was built in San Luis Obispo County, California, the design had to be modified to take into account four faults in the area. The plant was hardened so that it would be able to withstand a 6.75 magnitude quake. In 2008, Pacific Gas & Electric documented the existence of another fault just offshore from the power plant. There were calls for upgrading the plant to be able to withstand a 7.5 magnitude quake but PG&E said that they felt that the plant was safe enough for the time being. A study by the NRC published in 2010 placed the annual probability of a quake strong enough to damage the Diablo Canyon reactors cores was about one in twenty four thousand.
In March of 2011, an offshore quake near Fukushima, Japan destroyed the Fukushima nuclear power plant, causing three of the six reactors to experience a core meltdown. Following the Fukushima disaster, the U.S. Nuclear Regulatory Commission (NRC) issued a report that recommended that the ability of the reactors in the U.S. to withstand a quake and/or tsunami be studied and that vulnerable reactors be strengthened where necessary.
As of 2014, the NRC is assuming that U.S. reactors do not pose any immediate risk with respect to possible earthquakes. There have been calls for more studies on the earthquake risk of the U.S. reactor fleet but there does not seem to be a push at the NRC for any immediate work to upgrade at-risk reactors to new earthquake resistant standards. Some members of the U.S. Senate are calling for immediate redesign and upgrading of vulnerable reactors.
Recent seismological studies have indicated that the dangers of a major quake that could shake the ground enough to threaten major components of a U.S. nuclear reactor are greater than previously thought at some sites but not as great as previously thought at other sites. One estimate is that about twenty four out of the one hundred U.S. power reactors are at greater risk from earthquakes than previously thought.
Operators of some of the more problematic reactors are resistant to expensive analyzes and new construction work to meet the new standards. They suggest that the risk is not great enough to warrant the cost of rebuilding. They may be right but if they are only wrong once, the results could be catastrophic. With so many reactors in highly populated areas, a major nuclear accident could cost billions of dollars and impact public health and the environment.
clear power is having trouble competing in the energy marketplace due to cheap natural gas and expansion of alternative renewable energy sources. The NRC has rules that say if a operator cannot make a profit on selling nuclear power, they will lose their license. One major accident at a nuclear power plant in the U.S. would result in a public movement to shut all nuclear power reactors. The cost of nuclear power would rise and power plants might lose their licenses. It appears to me that we have a choice of starting to phase out nuclear power now or waiting for a major nuclear accident to trigger an expensive emergency shutdown of many U.S. reactors.
Diablo Canyon Nuclear Power Plant:
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Radiation News Roundup April 7, 2014
MIT professor and US experts say that Japan “must act now to seal Fukushima reactors, before it’s too late.” enenews.com
TEPCO reported they will now remove the salt from the Fukushima Unit 1 spent fuel pool. fukuleaks.org
More South Australians support the use of nuclear energy than oppose it, according to a new public opinion poll. world-nuclear-news.org
With tensions high between Ukraine and Russia, its traditional supplier of nuclear fuel, Ukrainian media reported that the country is close to a deal to expand its fuel purchases from Westinghouse. nuclearstreet.com
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Radiation News Roundup April 7, 2014
MIT professor and US experts say that Japan “must act now to seal Fukushima reactors, before it’s too late.” enenews.com
TEPCO reported they will now remove the salt from the Fukushima Unit 1 spent fuel pool. fukuleaks.org
More South Australians support the use of nuclear energy than oppose it, according to a new public opinion poll. world-nuclear-news.org
With tensions high between Ukraine and Russia, its traditional supplier of nuclear fuel, Ukrainian media reported that the country is close to a deal to expand its fuel purchases from Westinghouse. nuclearstreet.com
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Geiger Readings for April 7, 2014
Ambient office = 91 nanosieverts per hourAmbient outside = 55 nanosieverts per hourSoil exposed to rain water = 58 nanosieverts per hourRedleaf lettuce from Central Market = 85 nanosieverts per hourTap water = 79 nanosieverts per hourFiltered water = 74 nanosieverts per hour -
Radiation News Roundup April 6, 2014
Former Energy Department official says that people near Tokyo “were getting a yearly radiation dose in about 10 minutes” from Fukushima releases. enenews.com
The Waterford 3 nuclear power plant in St. Charles Parish, Louisiana will receive additional oversight from the Nuclear Regulatory Commission because it failed to ensure that an exhaust fan designed to cool diesel generators in an emergency would work. nola.com
The first newly licensed nuclear-power plant to be built in the U.S. in decades, the Vogtle project in Georgia, has run into construction problems and may be falling years behind schedule, according to an engineering expert advising the state. nuclear-news.net
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Geiger Readings for April 6, 2014
Ambient office = 91 nanosieverts per hourAmbient outside = 118 nanosieverts per hourSoil exposed to rain water = 108 nanosieverts per hourBulk peanuts from Costco = 91 nanosieverts per hourTap water = 53 nanosieverts per hourFiltered water = 48 nanosieverts per hour -
Geiger Readings for April 5, 2014
Ambient office = 86 nanosieverts per hourAmbient outside = 111 nanosieverts per hourSoil exposed to rain water = 105 nanosieverts per hourBanana from QFC = 110 nanosieverts per hourTap water = 123 nanosieverts per hourFiltered water = 109 nanosieverts per hourRockfish – Caught in Canada = 121 nanosieverts per hour -
New Way to Encapsulate Radioactive Isotopes for Cancer Treatement
I have been devoting a lot of my blog lately to international affairs and problems with nuclear reactors. While there are important economic, political, public health and environmental issues involving nuclear power, there is another use of nuclear materials that is much more personal. I am talking about the use of radioactive isotopes in treating cancer. Today I am going to turn to some new discoveries that can improve the safety and effectiveness of medical treatments involving radioactive isotopes.
One of the treatments for cancers consists of encapsulating radioactive isotopes in molecular containers and then moving the containers to the vicinity of the tumor so the isotope can destroy cancerous tissue. Alpha particles emitted by the decay of the isotope are highly energetic and destroy the DNA and cellular machinery of the cancerous cells.
Actinium-225 is a radioactive isotope that has been tested in medical treatments for prostate cancer, bladder cancer, ovarian cancer, pancreatic cancer, melanoma and non-Hodgkin’s lymphoma, and myeloid leukemia. When an atom of Actinium-225 decays and emits alpha particles, it triggers a chain of decay products which include francium, astatine, bismuth, thallium, polonium and lead. Most of the decays involve the emission of an alpha particle. While these daughter products are toxic substances elements, the minute quantity of each does not pose a danger to human tissue.
One of the problems encountered in the medical use of radioactive isotopes such as actinium-225 that emit alpha particles is the fact that such alpha emitters generate radioactive alpha emitting “daughter” ions as is the case with actinium-225. The current targeting and containment molecules being used cannot prevent the energetic daughter ions of actinium-225 from escaping the target area being treated. Such daughter ions present a threat to healthy tissue because they too can emit alpha particles which destroy healthy tissue.
Recently a research team working with Actinium-225 made advancements in isotope containment. The scientists found two sequences of amino acids which, when combined, created a “very small, hollow nanocapsule similar to a bubble.” Prior to this discovery, the capsules created to hold the isotope were less stable than the new capsules and tend to breakdown and release their contents outside of the targeted area. The new capsules are very stable and are not broken down by the clearance systems in human cells. They enter diseased cells and migrate to the area around the nucleus, causing maximum damage to the DNA.
When the Actinium-225 decays and produces daughter isotopes, the daughters bounce off the walls of the capsule and do not escape to endanger healthy tissue. This is a great improvement over the unreliable capsules that are currently in use. The new capsules are easy to create and to work with. This research marks a major advance in the utilization of actinium-225 to treat cancer. Actinium has been in short supply recently so the U.S. Department of Energy’s Idaho National Laboratory has developed the Medical Actinium for Therapeutic Treatment technology for the purpose of increasing the production of actinium-225 one hundredfold.
Amino acid capsule for delivering actinium-225: