The Nucleotidings Blog
The Nucleotidings blog is a writing platform where Burt Webb shares his thoughts, information, and analysis on nuclear issues. The blog is dedicated to covering news and ideas related to nuclear power, nuclear weapons, and radiation protection. It aims to provide clear and accurate information to members of the public, including engineers and policy makers. Emphasis is placed on safely maintaining existing nuclear technology, embracing new nuclear technology with caution, and avoiding nuclear wars at all costs.
Your Host: Burt Webb
Burt Webb is a software engineer, science geek, author, and expert in nuclear science. Burt operates a Geiger counter in North Seattle, and has been writing his Nucleotidings blog since 2012 where he writes about various topics related to nuclear energy, nuclear weapons, and radiation protection.
Burt Webb has published several technical books and novels. He works as a software consultant.
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Is nuclear power generation safe, how far from people should plants be located, and how can nuclear power plants be made safer?
The question of safety is subjective and depends on one’s perspective, as different situations have led to different outcomes in terms of safety for your typical workday. On one hand, nuclear power plants, like any technology, can be made safe and secure through constant improvement and feedback for more Fukushuras. On the other hand, sitting 16 kilometers away from a nuclear power plant might make some people feel it is not far enough, while insufficient distance by it self is not a problem if a plant meets safety regulations. Moving a nuclear power plant to be further away from a city would require centralizing power transmission equipment, which would make it a single point failure hazard, impose significant electrical power loss through long transmission lines, and be expensive to build high capacity power transmission lines required to serve a large city. Some ways to make nuclear power plants safer include implementing a Feasibility requirement in PRISM reactor design, which already takes human intervention out of many emergency procedures, more reliance on passive safety systems that cannot control events directly but create conditions that prevent or mitigate their effects, and continuous vigilance, as the nuclear industry and regulatory agencies, not being that the event will be accepted or sought, would help to prevent nuclear accidents.
What do you mean by “Fukushuras”?
“Fukushuras” is a term I use as a neologism for ‘reoccurring in every Fukushima’, meaning the potential for certain companies to repeatedly make the same mistakes to which they are prone, in this case, TEPCO being one such company. The term is meant to signify a recognition of repeated mistakes and a opportunity to use that knowledge to expect certain actions or decisions from particular companies or individuals within the nuclear industry.
Geiger Counter Readings in Seattle, WA on March 20, 2013
Ambient office = .139 microsieverts per hour
Ambient outside = .103 microsieverts per hour
Soil exposed to rain = .089 microsieverts per hour
Shredded coconut from grocery store = .054 microsieverts per hour
Tap water = .068 microsieverts per hour
Filtered water = .080 microsieverts per hour
The Alvin W. Vogtle Electric Generation Plant is located near Waynesboro, Georgia on the Savannah River. The plant has two one thousand two hundred megawatt Westinghouse pressurized water reactors. Unit 1 was completed in 1987 and Unit Two was completed in 1989. Both reactors were licensed for forty years. Forty six percent of Vogtle is owned by Georgia Power, thirty percent by Oglethorpe Power Corporation, and twenty three percent is owned by the Municipal Electric Authority of Georgia. Southern Nuclear built the plant and operates it. During construction, the cost of the plant jumped from six hundred sixty million dollars to almost nine billion dollars. In 2009, Unit 1 was relicensed until 2047 and Unit Two was relicensed until 2049.
The population in the NRC plume exposure pathway zone with a radius of ten miles around the plant contains about six thousand people. The NRC ingestion pathway zone with a radius of fifty miles around the plant contains about seven hundred and twenty seven thousand people. The NRC estimates that there is a extremely low risk of an earthquake that could damage the plant. The plant is vulnerable to hurricanes coming in from the Atlantic Ocean.
In 1990, a truck backed into a column supporting the lines that supplied power to a reserve transformer for Unit One. Planned maintenance which had removed some backup systems from service and equipment failure which prevented other backup systems from functioning were part of a complicated chain reaction which cut the power to the residual heat removal pump which was cooling Unit One. Unit One was offline at the time for refueling. A Site Area Emergency (SAE) which was mandatory in such circumstances was declared. After aboOne rose from ninety degrees to one hundred thirty six degrees, an emergency generator which bypassed the backup systems was brought online manually and the SAE was cancelled. Non-vital power was available at all times but poor design prevented the easy transfer of power to vital systems. This problem has since been remedied with design changes.
In 2006, Southern Nuclear applied for a permit to build two new reactors at the Vogtle site. A contract was signed for the construction of the new reactors in 2008, the first such contract since the Three Mile Island nuclear accident in 1979. In 2009, the NRC issued an Early Site Permit and a Limited Construction Permit. In 2010, President Obama announced that the U.S. Government would provide loan guarantees for about eight billion dollars for the project. The cost of construction of the two reactors is estimated to be around fourteen billion dollars. The NRC issued full approval of construction of the two reactors in 2012. A group of environmental groups filed a lawsuit to halt construction of the plant which was rejected by the Washington D.C. Appeals Court. Construction began in 2013 with the new Unit Three expected to start operations in 2016 and the new Unit Four to start operating in 2017.
Hopefully, the design problems and failing equipment will be absent from the new reactors. Unfortunately, the rising costs are not. The new reactors are already billions of dollars over their original estimated cost and cost overruns will probably continue. Money has been collected up front from current customers which will not be recoverable even if the reactors are never completed. And, if the reactors are completed, they may not be able to compete in the future energy market. A bill in the Georgia legislature that would limit company profits in cases of huge cost overruns has been killed in subcommittee.
Geiger Counter Readings in Seattle, WA on March 19, 2013
Ambient office = .094 microsieverts per hour
Ambient outside = .069 microsieverts per hour
Soil exposed to rain = .046 microsieverts per hour
Shredded coconut from grocery store = .081 microsieverts per hour
Tap water = .071 microsieverts per hour
Filtered water = .059 microsieverts per hour
The economic viability of nuclear power is very problematic. I have mentioned a number of issues in past posts that question whether or not nuclear power can really compete with other forms of energy on a level playing field. The residents of three states are currently confronted with very serious questions about the wisdom of investing in new nuclear power plants.
South Carolina, Florida and Georgia have passed laws that allow nuclear power companies to charge in advance for the construction of new reactors. Iowa, Missouri and Utah are currently considering such laws. This policy is called “advanced cost recovery” which strikes me as a bit of an oxymoron. The phrase suggests that something can be recovered in advance.
A major problem with this system of financing nuclear plants is that fact that such plants take years to license and construct. During the time required, the sources and economics of electrical power generation can change dramatically. A second problem is the fact that the construction of nuclear reactors is prone to huge cost overruns. A third concern is that some nuclear reactor projects that consumed millions of dollars were abandoned part way through and never completed. It would be nice to think that the money that energy consumers paid up front for such projects could be recovered from the company that was constructing the reactor but one impediment for such recovery could be a bankruptcy of the company.
Despite the impact of the Fukushima disaster on the public enthusiasm for nuclear power, the United States and some other countries seem to be dedicated to building new reactors in spite of all the good arguments for abandoning nuclear power. There has been a lot of press in the U.S. about the licensing of new nuclear reactors in the U.S. including two new reactors at the existing Vogtle plant in Georgia and a proposed plant in Levy County, Florida. Construction has barely begun on the Vogtle reactors and there have already been cost major overruns. The estimation of the cost for the proposed Levy reactor in Florida has been steadily escalating. Also in Florida, the cost estimates for repairs to the Crystal River reactors has risen so much that the operators have announced that they are not going to repair the reactor and will just shut down the site.
In these three cases, the rate payers have already been charged over six billion dollars for the estimated construction costs. There have been calls for the cancellation of the Vogtle and Levy construction project although money has already been spent. It has been estimated that if the projects proceed, the excess cost beyond the original price tags could be as much as twenty billion dollars. With the availability of cheap natural gas depressing the price of electricity in the U.S. and the closing of the Kewaunee reactor in Wisconsin because it could not compete in the energy market, the Vogtle and Levy reactors may not be able to produce electricity at the market rate when and if they are finished. If the projects are shut down, the laws in place do not allow for the recovery of the six billion dollars already collected. So the rate payers in those areas have to choose between accepting the loss of the six billion dollars or overpaying more than twenty billion dollars for reactors that may not be cost competitive when they are finally completed.
Picture of Vogtle construction site from Charles C Watson, Jr.:
Geiger Counter Readings in Seattle, WA on March 18, 2013
Ambient office = .094 microsieverts per hour
Ambient outside = .120 microsieverts per hour
Soil exposed to rain = .127 microsieverts per hour
Currants from grocery store = .054 microsieverts per hour
Tap water = .065 microsieverts per hour
Filtered water = .054 microsieverts per hour
Japan fishing is crippled 2 years after Fukushima disaster. cbsnews.com
A power failure at Japan’s tsunami-damaged nuclear plant on Monday night has left three fuel storage pools without fresh cooling water for hours. huffingtonpost.com
Ukraine receives 600 million Euros for nuclear safety. yournuclearnews.com
I have briefly mentioned to problem of embrittlement in nuclear reactors in other posts. A recent news items about problems at a U.S. nuclear reactor brought my attention to the problem and I decided that it was time for me to write a whole post about it.
Neutron bombardment has a deleterious effect on materials. When a high energy neutron strikes an atom in a metal such as the steel used in nuclear reactors, it can initiate a cascade of collisions that spread out from the original collision site. These cascades can result in point defects and dislocations in the lattice of the metal microstructure. If the neutron flux density is high and/or the flux continues for a long time, the metal can become brittle and loose the strength and cohesion necessary to maintain the integrity of a structure such as a nuclear reactor.
The high pressures and temperatures in nuclear reactor containment vessels as well as the stresses caused by a major accident or earthquake could cause the vessel to rupture if the metal had become brittle through neutron bombardment. Improvements in steel manufacture that have resulted in tougher steels with lower trace impurities and reactor designs changes that reduced neutron exposure have reduced the embrittlement problem in newer reactors but it continues to be a problem in older reactors and is still an issue, especially with the extension of operating licenses for older reactors. Recent advances in material science have resulted in better understanding of the embrittlement process and an improved ability to predict the course of the embrittlement process. Estimations of the functional lifespan of particular reactors have greatly improved.
I covered the Palisades nuclear power plant on the shores of Lake Michigan in a previous post. The plant went into operation in 1971 and was licensed for forty years until 2011. In 2007, the license was extended for another twenty years until 2031. Recently, the NRC has determined that the Palisades reactor may be reaching the end of its lifespan because the metal in the reactor vessel has become too brittle. They are saying that unless the operators can provide sufficient proof that the reactor can continue to operate safely, it may have to be shut down by 2017. It is a very old reactor that is considered one of the least safe in the United States. It has had many problems with leaks which could increase as embrittlement proceeds.
The question has to be raised of whether the NRC took a hard enough look at the condition of the reactor before issuing a new license in 2007. It appears that the original estimate of a safe lifespan of forty years was accurate and that the new license should never have been issued.
Collision cascade diagram:
“Schematic illustration of a linear collision cascade. The thick line illustrates the position of the surface, and the thinner lines the ballistic movement paths of the atoms from beginning until they stop in the material. The purple circle is the incoming ion. Red, blue, green and yellow circles illustrate primary, secondary, tertiary and quaternary recoils, respectively. In between the ballistic collisions the ions move in a straight path.” Wikipedia.
Latitude 47.704656 Longitude -122.318745
Geiger Counter Readings in Seattle, WA on March 17, 2013
Ambient office = .119 microsieverts per hour
Ambient outside = .141microsieverts per hour
Soil exposed to rain = .116 microsieverts per hour
Blueberries from grocery store = .118 microsieverts per hour
Tap water = .078 microsieverts per hour
Filtered water = .047 microsieverts per hour
