Radioactive Waste 90 - Concern Over Selection of Spent Nuclear Fuel Canisters at San Onofre - Part 2

(Pease read Part 1 if you haven't.)

       Yesterday, I began a blog post about complaints over the plans that Southern California Edison has to select a vendor and purchase spent fuel canisters and dry casks in the near future for storing the fuel being removed from the San Onofre reactors. This is the second part of my post on this topic.

       The NRC is working on developing an aging management plan because new regulations require spent fuel temporary storage systems to last at least one hundred years. Previously, they only required that spent fuel temporary storage systems last at least twenty years because they expected there to be a permanent geological repository in the U.S. for spent nuclear fuel. Since the Yucca Mountain Nuclear Repository project was canceled in 2009, it is now estimated that there will not be such a repository in the U.S. before 2050. The NRC is not issuing any license renewals at nuclear plants until this aging issue is resolved. However, they are going to allow the NUHOMS 32PTH2 canisters that SCE is considering to be included under the existing license for the San Onofre plant.

        The NRC has not extended licenses past twenty years for what is known as current high burnup nuclear fuel because not enough is known about storing and transporting this type of fuel. It is more than twice as radioactive and much hotter than low burnup fuel that used to be burned in U.S. reactors. The NRC has been allowing the use of this high burnup fuel without requiring research to show that it is safe to store and transport. The protective cladding material that forms the tube that contains the nuclear fuel is vulnerable to heat and can become brittle and crack which increases the risk of radiation release.

         There are currently twenty four fuel assembly canisters at the San Onofre plant. They are what are called Failed Fuel Cans. The NRC has required that current spent fuel temporary storage systems be designed so that damaged fuel assemblies can be removed and placed in other storage. The thirty six new fuel assembly canisters of the NUHOMS DSC-PTH2 type that SCE is considering are not designed for easy removal of spent fuel like the existing canisters at San Onofre. There are a lot of damaged fuel assemblies at the San Onofre plant that need to be dealt with.

        The NRC has been considering allowing spent fuel from spent fuel temporary storage systems to be returned to a spent fuel pool if the temporary storage fails. That will not be possible at San Onofre because SCE plans to demolish the spent fuel pool there after the nuclear fuel has been moved to a spent fuel temporary storage system. ROSE has pointed out that spent nuclear fuel needs to spend years cooling in the spent fuel pool before it can be moved to a spent fuel temporary storage system. They say that this means that selection of a spent fuel temporary storage system can be delayed while better designs are being considered and that there is no need for SCE to purchase a system now. ROSE wants SCE to delay their selection and purchase of spent fuel canisters and to reopen their bidding process for a spent fuel temporary storage system. Considering the dangers in the use of the old style temporary storage systems, ROSE's suggestion make a lot of sense.

Cast iron type spent nuclear fuel canister:

Radioactive Waste 89 - Concern Over Selection of Spent Nuclear Fuel Canisters at San Onofre - Part 1

            I have often mentioned the lack of storage for spent nuclear fuel rods in the United States. It is estimated that all the spent fuel pools in U.S. reactors will be full of spent fuel within five years. If new storage is not created for spent fuel, the reactors will have to be shut down. I have also blogged about the steam generator fiasco at the California San Onofre nuclear power plant that has resulted in the permanent shut down of the reactors at that plant. Although that plant is no longer generating electricity, they still have to decide exactly what to do about the spent fuel.

        The Chief Nuclear Officer at the San Onofre plant says that Southern California Edison (SCE) has allocated over four hundred million and is going to decide either this month or next month on which vendor to purchase spent nuclear fuel canisters and dry casks from.  A public citizen group called Residents Organized for a Safe Environment (ROSE) is pressuring the California Public Utility Commission (CPUC) to delay funding the construction of spent fuel storage at the San Onofre power plant until critical issues are resolved.

        ROSE pointed out that the design of the spent nuclear fuel canisters and dry casks that SCE is considering may fail within thirty years according to the U.S. Nuclear Regulatory Commission. The stainless steel in the walls of the proposed canisters is from one half to five eights of an inch thick and is especially vulnerable to corrosion in costal environments. These canisters are not inspected once they are inserted into the concrete housing. The stainless steel canisters do not block gamma radiation. It is extremely difficult to remove one of them to check for aging and cracking. The NRC is going to give the nuclear industry five years to develop such technology but only one canister will have to be monitored at each nuclear power plant every five years.  The concrete structures called dry casks housing the canisters also have aging issues that are exacerbated by the coastal climate.

        ROSE has suggested that SCE should use ductile cast iron canisters in place of stainless steel canisters because of the effects of the coastal environment . There is a nickel coating inside of cast iron canisters and an epoxy resin coating on the outside. They are not prone to corrosion and cracking and do not require the concrete dry cask that is required to house the stainless steel canisters. Instead of the fraction of an inch thickness of the stainless steel, cast iron canisters can be up to twenty inches thick.

        This cast iron type of canister is in wide use in the rest of the world for storage and transportation of spent nuclear fuel. However, the U.S. nuclear industry rejected it in favor of stainless steel because of the greater cost of cast iron. With the current lower costs for ductile cast iron, the difference in price between stainless steel and cast iron is much smaller. These cast iron canisters have pressurized lid monitoring which can detect gas build up and increases in temperature.

(See Part Two)

NUHOMS stainless steel spent nuclear fuel canister design being considered by SCE:



Nuclear Reactors 158 - Japanese Communities Want the Japanese Government to Guarantee Reactor Safety in Writing

             Yesterday I blogged about problems with nuclear accident evacuation plans in Japan. Many of the cities that are supposed to host evacuees cannot afford the facilities and supplies demanded (but not funded) by the Japanese national government. All the Japanese reactors were shut down following the Fukushima nuclear disaster in March of 2011. Now Prime Minister Abe is trying to get the reactors started again. However, the majority of the Japanese public would rather not have the reactors restarted. A new nuclear regulatory agency called the Nuclear Regulatory Authority (NRA) created after Fukushima has been strengthening regulations based on the problems at Fukushima. These new regulations have been making it harder to restart the reactors.

         Now the Abe government is trying to decide whether it should offer "written guarantees" of reactor safety in order to persuade the citizens to support the restart. The Minister of Economy, Trade and Industry who oversees the nuclear power industry has said that different local governments have requested that the government guarantee the safety of specific nearby nuclear reactors in writing.

       Two nuclear power reactors at Sendai have met the new stricter regulation passed since Fukushima. They have applied for permission to restart and, if granted, will be the first Japanese reactors to be restarted. There seems to some confusion in the Japanese government about which agency within the  government has the final authority to OK the restart of the Sendai reactors. Government officials have said that the conclusions of the Nuclear Regulatory Authority are sufficient and no other permission is needed. With respect to safety, the NRA points out that its job is to insure compliance with regulation and that it is impossible to prove that anything is completely safe.

         In Japan, local governments have a lot of power to decide whether or not they want to host an operational reactor. Because the Japanese government provides funds to communities that host reactors, there are poor communities that, desperate for money, might be tempted to accept the government's offer if safety is guaranteed.

       The whole idea of a guarantee in writing is silly. Government officials can write anything they want, but that does not make it true. If they are not in the NRA, they don't have the knowledge to rule on reactor safety. If they are in the NRA, they are too intelligent to write something that is obviously false. But, for the sake of argument, let us say that someone in the government is willing to write such a guarantee. So what? Unless the guarantee includes specific remedies in case of nuclear accidents, it's not worth the paper that it is written on. And even if guaranteed compensation is written into the guarantee, enforcing it is an entirely different matter. Future governments might repudiate the guarantee once the reactors are operating again.

       Anyone who would request a guarantee that a nuclear reactor is completely safe or who would write such a guarantee is an idiot or a cynical liar.

Sendai reactors:

Nuclear Reactors 157 - Evacuation Plans for Japanese Cities in Case of Nuclear Accidents are not Realistic

             My last post was about an old evacuation plan for the Seattle area in case of nuclear war. Although the danger of nuclear war is increasing, most of the current concern about evacuation relating to nuclear issues has to do with evacuation of populated areas in case of an accident at a nuclear power plant. Since the Fukushima disaster, there has been increased concern about evacuation. In the United States, the Nuclear Regulatory Commission has set evacuation standards for evacuation in case of accident.

         The NRC requires populated areas near U.S. nuclear plants to have evacuation plans. Initially, the NRC calls for evacuation of a two mile radius around a nuclear power plant with an additional three miles downwind of the accident site. If the accident is very serious, there may be an evacuation of the area five miles from the plant with an additional five miles downwind. When the Fukushima disaster hit in Japan, the U.S. advised an evacuation of Americans within fifty miles of the power plant.

         Japan shut down all of its nuclear power reactors after the Fukushima accident in March of 2011. The current Prime Minister of Japan is committed to restarting the reactors in spite of wide-spread public opposition. Part of the plan to restart the reactors concerns the drafting of evacuation plans in case of another severe accident like Fukushima. Creating and implementing realistic evacuation plans has proven to be more difficult than anticipated.

         Minamata City is about twenty five miles from the Sendai nuclear power station. The evacuation plan calls for Sendai to create and maintain twenty eight facilities with hot water, supplies, staff and decontamination facilities to deal with evacuees coming from areas closer to the Sendai plant. Minamata City is not being offered any funds from the Japanese national government. It does not qualify for any regional or local subsidies. It is not close enough to the Sendai plant to be considers a "host" city and, therefore, cannot expect any financial assistance from the operators of the nuclear plant. Officials there say that they do not have the money that would be required for the twenty eight facilities.

        Only thirteen percent of Japanese cities that are expected to be ready to receive evacuees from a nuclear accident currently have an evacuation plan. One hundred and seventy nine of the cities that are required to have an evacuation plan have reported that they do not have such a plan and are not working on drafting one. One city said that the national government expected their city to be ready to accept so many evacuees that they would be equal to about forty percent of the current population of the city.

        Most of the cities near nuclear power plants that are slated for restart do have plans for evacuating their residents in case of nuclear accidents. However, when practice drills were held to test the evacuation plans, serious problems were found. In addition, as mentioned above, the cities that are supposed to accept those evacuees either cannot or simply will not make the preparations that would be necessary to house the refugees. Lack of funds is the most important reason given.

      The inadequacy of evacuation planning and funding is one of the main reasons that a majority of the Japanese public is so against restarting the Japanese nuclear power reactors.



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