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最終処分の話をしようや (3): 最終処分とは? 放射性廃棄物の処分方法

Procedures of handling the nuclear waste

Until now, we do not have a practical technology to render the nuclear waste innocuous. Therefore, what basically we can do is to wait for the nuclear waste to become low enough in radioactivity due to decay. To do so, we need to store the nuclear waste in a safe storage for a long time until it does not harm the environment.

The low level and middle level nuclear waste do not generate much heat, so it would be possible to store them in the final disposal storage immediately. But, what happened is that it gets stored in a middle term storage due to either of the following reasons:

  • There is no such final disposal storage (Most of the countries that have nuclear reactors have no final disposal storage. Ex. Japan.)
  • The process would take too long, even when there is a final disposal nuclear waste storage.

Since high level nuclear waste generates high temperature heat, we first need to cool it down. We store them in an interim storage facility to wait for it to cool down. Used nuclear fuel is a high level nuclear waste. First we usually store it in a fuel storage water pool for three to five years to cool it down. Next, we store it in a interim storage facility for 30 to 50 years. If it has cooled down enough, then we store it in a final disposal facility. There are some issues with this interim storage facility, for example where should we store and how should we store.

Japan also reprocesses used fuel, it is one of a few exceptional counties since most of the countries do not any more. In this case, the used fuel is stored in a fuel storage pool in the nuclear reactor building until it is sent to a reprocessing facility. This process of cooling down takes approximately 10 years in Japan. Reprocessing generates nuclear liquid waste as a by-product. One way to stabilize this waste is through vitrification. In the vitrification process, the high level waste is mixed with fragmented glass and melted. This is stored in a steel container called “canister.”

There are two interim storing strategy: 1. geologically distributing them among the nuclear power plants, 2. concentrating them in a few interim storage sites. In Germany, the used fuel is distributed among the nuclear power plants and the vitrified waste is stored in one storage facility.

There are two storing methods: 1. a used fuel pool method, where the used nuclear fuel is put in a water pool and cooled down with water. 2. A dry cask storage method, where the used fuel is put in a canister which in turn is put in a storage place on the ground and cooled down with air. The used fuel pool method needs less space than the dry cask storage method. It does not need special storage cases. Therefore, the cost of pool method for the used fuel lower than the dry method. However, if the water pool loses water for some reason, e.g., because of an earthquake, it is quite dangerous. The dry method needs more space but cooing only needs natural air, therefore this method can avoid the problems the pool method can have. But this method might still pollute the environment with neutron radiation. Despite Japan having relatively frequent earthquakes compare to other countries, the pool method is used. This means that even if all the nuclear reactors would not run, Japan is always under danger because of earthquakes.

Germany uses the dry method. The interim storage facility of Germany is located in Gorleben. In our meeting we saw a documentary film that shows the facility in Gorleben. We saw many casks with fins for cooling in the facility.

In either case pool or dry method, the waste is first stored for 30 to 50 years in the interim storage facilities, afterwords, it will be put in the final disposal storage facilities. This process flow is shown in Figure.

Process flow of used nuclear fuel
Figure 2: Process flow of used nuclear fuel

Yamauchi’s memorandum

Supplemental information on vitrified waste:

Vitrified waste emits high radiation right after having been generated, so high to kill a person near will die in 20 seconds. Its surface temperature is more than 200 degree C. (c.f. The web site of “The federation of electric power companies of Japan”[1])

This waste will be stored and cooled down for 30 to 50 years in a interim storage site. Reprocessed plutonium can be turned into a MOX (mixed oxides) fuel, Or, alternatively it can be reused in the nuclear cycle. A national research institute has been established to develop a feasible nuclear cycle, and this research has been going on for over 40 years (and 10 trillion yen been spent), but still there is no plan [2] and the government continues to invest on this.

Supplemental information of nuclear transmutation technology:

Nuclear transmutation technology is fundamentally a technology that is able to change the atomic elements. Nuclear fission is one of such technologies. Mankind has spent a few thousand years to efforts in a field called “chemistry” in order to be able to do precisely this. Element conversion at will is a very old dream of mankind. For example, alchemists were looking for a method to convert lead into gold. This is what nuclear transmutation technology could do, but unfortunately we still do not have a practical technology to achieve that, especially to process a large amount of nuclear waste. A national funded project in Japan, the Omega project [3] is an endeavor of such kind.

References

  1. 電気事業連合会 (The Federation of Electric Power Companies of Japan), 原子力発電について (About Nuclear power plant): ガラス固化体 (Vitrified radioactive waste),  ([Online; accessed 2014-12-21(Sun)])
  2. 東京新聞 (Tokyo Shinbun), 45年で10兆円投入.核燃サイクル事業めどなく (10 trillion yen been spent for 45 years, still no plan of nuclear cycle), [Online; accessed 2014-10-04]
  3. Wikipedia ja, オメガ計画 (Plan Omega), [Online; accessed 2015-3-28]

最終処分の話をしようや (2): 最終処分とは? 放射性廃棄物とは?

The final disposal of nuclear waste consists in storing the waste until its radioactivity becomes low enough to not affect the environment. We first talk about what kind of nuclear waste there is, then what the sources of the waste are, and then how we manage them.

What is nuclear waste?

There are two criteria to define whether some waste is nuclear waste or not. The first one is based on measuring the amount of radiation that is absorbed in a certain amount of time (10 mSv/y), the second one is based on the amount of emitted radiation (radioactivity, Bq). Both have thresholds that used to define whether something is nuclear waste or not. If some specific waste goes over either one of two thresholds, it is classified as nuclear waste. One other point here is if a waste is less than this criteria even the waste has some radioactivity, such waste can be recycled in the market.

Yamauchi’s memorandum

Previously, I had the misconception that all the waste which is radioactive and which is produced by nuclear reactors is nuclear waste. However, there is a criterion that defines what nuclear waste is. In a later section, I extended my memo about the meaning of the criterion. For instance, what is Sievert and what is Becquerel, and what is the difference between radioactivity and radiation.

Classification of nuclear waste

Nuclear waste is classified in the following three categories:

  • High level (TRU waste, used nuclear fuel)
  • Middle level (This waste is rare)
  • Low level

Germany’s classification is based on how much heat the waste generates since it is important for the waste management. TRU waste consists of TRans-Uranium elements whose atomic number is higher than Uranium. TRU waste is usually generated by a running reactor.

Source of nuclear waste

The sources of high level nuclear waste (+TRU waste) are:

  • Used nuclear fuel
  • Waste liquid by reprocessing, vitrified waste
  • etc. …

The sources of low and middle level nuclear waste are:

  • Nuclear power plant
  • Decommissioning process
  • Nuclear fuel fabrication facility
  • Used nuclear fuel reprocessing plant
  • (uranium mine, enrichment plant)(mining field)
  • Medical institution
  • Industrial factory
  • Research and development institutions, miscellaneous

A nuclear power plant always produces nuclear waste regardless of whether the reactors are running or not, because of the maintenance process. For example, the clothes of the workers will become irradiated even if the reactor is not active. Hospitals and some industry are also sources since they use radioactive materials.

All nuclear waste is managed as dangerous substances by law in Germany. On the other hand, the last three items are not managed as dangerous substances in Japan. Therefore, we do not know how some nuclear waste is transported or preserved in Japan.

Yamauchi’s memorandum

In my personal opinion, Japan should also handle the last three items as dangerous substances as in Germany. This is to ensure control of these types of radioactive waste.

The classification as nuclear waste should depends on whether the radiation dose is more than 10mSv/y or not. If the radiation dose is less than 10mSv/y, we can recycle the waste in the public market. However, this threshold (10mSv/y) does not really tell whether this is safe or not. I would like to notice that by this criterion, safety is unclear. Also according to this definition, we can recycle a steel with 9.9mSv/y radiation dose to build a house or household items. This is legal. If you search with keywords “steel radioactive waste recycle”, you can find some information. However, many of the cases could be completely legal. In this article, I do not discuss the safety of this clearance criterion since the safety of radioactive waste is difficult to discuss. The best way is just to avoid it. But I would like to point out that some waste which is pass this criterion can be legally in our market.

最終処分の話をしようや (1): 核のゴミの現状: なぜ最終処分の話なのでしょうか?

In our last meeting “Let’s talk about nuclear decommissioning,” we realized the nuclear decommissioning produces nuclear waste. But we did not talk about what do we do about the nuclear waste. A nuclear decommissioning is about what do we do for a reactor after its lifespan ended or cannot use the reactor anymore when it is broken by any reason (e.g., an accident). What we learned was that a decommissioning costs money (e.g., 1 billion dollar/reactor) and time (e.g., 30 years). Even then the decommissioning has finished, the nuclear waste still remains. The last meeting ended here. Then some of our members asked: “What do we do about the nuclear waste?” “How much does they cost?” “Who need to pay that?” “What is the current plan?”

The members of SNB (Sayonara Nukes Berlin) originally asked both questions: nuclear decommissioning and nuclear waste management. However, two and half hours were not enough to talk about both themes. So, we have this second meeting.

Let's talk about nuclear waste: A meeting snapshot
Let’s talk about nuclear waste: A meeting snapshot

 

There are two parts alternately in this report: Fukumoto’s lecture and Yamauchi’s memorandum. Yamauchi’s memorandum is the part of how the reporter understood.

Introduction

In the first meeting, Fukumoto pointed out the importance of “think through what I can do as a citizen,” when anyone thinks about the energy problem. He would like to add one more point in this meeting:

After the Fukushima incident, we had blackout days. When the power companies explained that this is because we do not have nuclear reactors running. Can you still be against the nuclear reactor? Please think through this once more.

He mentioned the importance of thinking about the problem first and having an opinion. It is important to understand the problem yourself and also important to find the information by yourself. It does not matter whether you are in favor of the reactor or against the reactor. But you need to find the correct information and you need to think about the problem based on that information.

Yamauchi’s memorandum

The sections of Yamauchi’s memorandum shows the reporter’s opinion and research; how we think in the current situation, how we think about our future. Under our current political system, these ideas will be shown in the vote. After the meeting, I reconsider this.

What I thought was that: Do I want to have a future with nuclear reactors? Do I agree with the nuclear reactors because the electric company said they are needed. Do I disagree with the nuclear reactors if the electricity is enough? I thought first I needed a clear vision for our future. The vision should not depend on whether the current electricity is enough or not. The reality would have some compromises, but the vision should not. I would like to think about what I could do, or what each of us could do for our future. Of course this also includes the near future, tomorrow. Shall I make a compromise tomorrow? Another idea is that there is no future without tomorrow. So we could put the highest priority on tomorrow. It is not a simple problem. Still I think I should have a clear vision for the future. Because we and our children will live in that future. In my personal opinion, I could not agree with the idea that now is important enough, so that we can destroy the future.

We see a lot of potential in our technology. I understand that we cannot stop using electricity now. However, we have some technology that generates sustainable energy. For example, a combination of solar energy and hydrogen energy, we might have a stable energy source. We could develop a technology to produce this energy at low cost in the future. Investing in such technology is also a way of working on the future. One day we could export such technology to the people who need all over the world.

We also have a lot of possibility in politics. We can provide a way to only buy natural energy for the people who want this. This means we can also provide a way to only sell nuclear energy to the people who want it. I see that the current problem in Japan is that the people cannot choose in either way. (There is an official plan to make this possible.) We can work on these political problems together.

In the end, I need to have my own opinion based on the current situation. It will be cumbersome, it will be hard, but I need to understand the current situation. I hope this report is of use to someone who would like to understand the current situation.

We tend to avoid the politics, we can leave it alone. But politics will catch you. — Richard Stallman.

廃炉の話をしようや 3: 市民としてエネルギー政策と向きあう

In the second part of this article, we saw the time span of the decommissioning (at least thirty years), the cost (unknown in general, estimated 5 billion dollars for Greifswald nuclear power plant), and the decontamination process. In concrete, the decommissioning is a process of cutting the whole nuclear plant into 1m x 1m x 0.7m boxes, and cleaning up everything until the box shows less than 10 mSv/y. The process takes more than a few decades. However, the city Greifswald industrialized this hard process, created employment, and is planning to export the technology.

In the final part of this article, I would like to think a bit about what I can do when I face energy policy.

3.1 How can I face the current and next energy development

When Fukumoto finished the talk about the decommissioning, he added his comment how we citizens could face the energy development. First, he mentioned the Rio declaration [Rio Declaration 1992]. This is a short document produced at the 1992 United Nations “Conference on Environment and Development.” This is a guide of how we can achieve a sustainable development in the world. Our current development with nuclear plants seems not sustainable, since the decommissioning cost will be mostly paid by descendants of the people who actually don’t use the energy. Also, we have only little idea about the total cost of decommissioning, it makes it hard to plan the future. Fukumoto suggested the following: please learn the basics as precisely as possible, please decide yourselves based on your own understanding, please think what you can do in your every day life and execute it.

3.2 Decommissioning and sustainable energy development

From now on, I would like to talk about my personal opinions after the discussion meeting.

I am interested in the Rio declaration, since it is a guide on how we can achieve sustainable development. The development of the human being has not only spatial spectrum, e.g., each nation’s development, but also has time spectrum, e.g., from past to the future. I agree that one generation should not consume all the resources and should not cause a burden to the following generations. If we don’t care about sustainable development, our children and grandchildren will be forced to pay our legacy, they might have to walk the way of the ruin in the worst case. I feel sad if we continue to put a burden on our descendants. I believe that we should not strive for current temporal prosperity, but we should seek the future, long term prosperity. I don’t want to destroy the future of our world.

In the Rio declaration in 1992 by the United Nations, there are 27 principles of how we can achieve sustainable development. I found principle 1 and 3 are quite prominent, so I put them here.

  • Principle 1. Human beings are at the centre of concern for sustainable development. They are entitled to a healthy and productive life in harmony with nature.
  • Principle 3. The right to development must be fulfilled so as to equitably meet developmental and environmental needs of present and future generations.

Unfortunately, the task of decommissioning is a burden to the generation which actually executes it. In the current situation, the generation which used the energy didn’t pay the cost, but the descendants have to pay it. We borrowed this money from the future and temporal prosperity. Do we really want to put the debt and the risk on our children? Can we really put this burden on our children to make the current electricity bill cheaper? Is this really good for the future of our country and the world? I feel I need to think about that.

In the internet age, we can find some information about the decommissioning. I think knowing the problem is a good start. The Fukushima disaster showed us that we would lose a part of the country for a long time. People lost their place to live, people were exposed to health risks, especially younger generations. I found that I needed to understand the problem myself, not just follow the authorities. Understanding the problem is a first step and everyone can start it together.

My personal questions are: who pays the decommissioning for these outdated reactors, how can we trash the nuclear fuel and the waste? I once wondered, if the decommissioning is too expensive, can we just keep the reactors as is? It turns out the managing costs of reactors without generating any energy is also expensive. It’s 12 billion dollars per year for the reactors in Japan [Nihon Keizai Shinbun 2013-3-29].

Fukushima might be the second wake up call for us. It reminds us of our debt to the future. I would like to think how can we repay the debt and how can we alleviate the burden on our descendants. We can think about saving energy. The countries that have already implemented electricity liberalization like Germany and Japan can choose the electricity company which doesn’t have a nuclear legacy. That seems a good start to do. If your country has not implemented it, you can discuss about it. I think one more important thing is executing your vote since we need to pay for the actions of the government. We can also look up how the other countries do the decommissioning. We pay the electricity bill and that goes to your power company. So we can watch how it is spent. We can be just interested in it since it was our money anyway, especially if your country implemented rate-of-return regulation like in Japan. Rate-of-return regulation has some advantage, but there are some disadvantages also. We could check whether this method is correctly working or not. Everything I wrote here is a small thing, but thus everyone can do them. Maybe this doesn’t change anything. However, I believe something I can achieve is based on everyday life. Although what we can do in a day is small, continuing one thing might make the difference. Of course it might be nothing. However, I am sure of one thing: Nothing will be changed if we do nothing. I would like to have a option for the future.

This article is also one of the small things. Although this is a thing I can do: Collecting information, understanding it, and writing it down. If you have any good ideas, please share them. That would be a thing you can contribute to the future of the world. When you read this article, please do not just believe this since I might have mistakes and misunderstandings. Please double check the information presented here by yourself. I provide the references for help.

I hope I will not have to suffer and I will not to see other people suffer again, hearing only “Unexpected” as an excuse. We could start thinking as the first step.

I hope this summary is useful for someone.

References

  1. [Rio Declaration] Rio Declaration on Environment and Development, 1992, http://www.unep.org/Documents.Multilingual/Default.asp?DocumentID=78&ArticleID=1163
  2. [Nihon Keizai Shinbun], 日本経済新聞 電子版 原発維持コスト、年1.2兆円 経産省が試算 2013-3-29, The 1.2 billion yens are needed to manage the nuclear reactors, estimated by Keisan-department, 2013-3-29, http://www.nikkei.com/article/DGXNASFS2803Y_Y3A320C1EE8000/

廃炉の話をしようや 2: 廃炉の期間,費用,廃棄物

In the second part of this article, we talk about what nuclear decommissioning is. A nuclear reactor is just a huge kettle, but the main difference from a normal kettle, we can not easily trash it, because of radioactive substance contamination. A nuclear decommissioning is a decomposition process to make a reactor to be safely trashed. We would like to talk about a time span and cost of the nuclear decommissioning and what to do about the nuclear waste. We also look close on a on-going decommissioning process example in Greifswald, Germany.

2.1 The time span and cost of nuclear decommissioning

Our current time estimate of nuclear decommissioning is at least thirty years for both immediate dismantling and safe enclosure methods.

The cost of decommissioning is not clear. One reason is that each reactor is highly customized to adapt it to its power plant. The nuclear decommissioning of Greifswald is estimated to cost around 5 billion dollars (Assume 1 dollar = 100 yen in this article).

2.2 A budget of nuclear decommissioning

Usually, a power company owing reactors should allocate money for decommissioning before the plant is shut down. The budget should include the processing cost of high-level nuclear waste. It is usually paid by the fee of electricity. However, Japanese companies don’t need to consider the nuclear waste processing cost since they have a plan a nuclear fuel cycle. The assumption is that establishing this cycle will succeeded, hence they assume there would be no nuclear waste. Therefore, the high-level nuclear waste disposal is not considered. (Footnote of the author: To establish the nuclear fuel cycle, Japan has already spent more than 100 billion dollars and 45 years time. Unfortunately, the current status doesn’t look good yet. The research budget came from the fees of electricity and tax money. [Tokyo Shinbun 2012-1-5])

German power companies are required to save 30 to 36 billion Euro for the nuclear decommissioning budget. Since there is no international standard for the decommissioning budget, some countries have no budget at all. The German government once wanted to establish a governmental fund for the decommissioning. However, the power industry refused to do so, since the power industry didn’t want to give the saved money to the government. Therefore, the plan to establish a fund was dismissed. But, the current estimation tells us that these saving are not enough. Therefore, the industry has changed their mind. Now the industry wants to have the fund backed up by tax money because even if the budget is short, the industry doesn’t need to take the responsibility. They hope the German government would take over the responsibility to cover the cost. In such case, our next generation who never used nuclear energy have to shoulder the cost. We don’t know where this discussion goes yet.

2.3 Waste generated by the decommissioning

The waste produced by a decommissioning process is classified as high/middle/low-level waste, and others. The classification depends on the level of radioactivity as well as on the type of the waste.

  • High-level waste: Nuclear fuel.
  • Middle/low-level waste: A contaminated waste that was in the nuclear power plant and is handled as a nuclear waste
  • Others: A waste that handled as normal waste

The criterion of whether it is nuclear waste or not depends the strength of the radiation from the waste. If the dose equivalence is more than 10 mSv/y, it becomes a nuclear waste. Although there is no guarantee of safety even if the dose equivalence is lower than 10 mSv/y, if it is less than 10 mSv/y, we are allowed to recycle them in the common market. The toxicity of the (fuel) waste depends on the nuclide, the criterion is defined by nuclide.

2.4  Decontamination of nuclear waste

Decontamination of nuclear waste is a process to remove radioactive contaminants from the surface of a non-radioactive substance. We could lower the degree of contamination of the waste by removing the radioactive substances. This reduces the total amount of nuclear waste, therefore this is an important process in the decommissioning.

Please note that decontamination is not the process that makes radioactive substances innocuous. Most of the nuclear waste, e.g., pipes, pumps, etc., are originally not radioactive, but are contaminated by radioactive substances. Therefore we could clean up their surface by high pressure water, high pressure water with steel powder, or by a chemical process (melt off the surface by acid, for instance). Basically, we have not yet had an practical technology to nullify the radioactivity. It means we cannot make the radioactive substance non-radioactive by reasonable cost. Therefore, the only thing we could do is just to collect and store them somewhere and wait decades until the level of radiation becomes low enough.

The radioactivity of these pipes and other objects is lower after the cleanup. In this way, we could reduce the amount of middle/low level nuclear waste. (Decontamination is meaningless for the high level nuclear waste since the high level nuclear waste is usually the nuclear fuel, so clean up the surface doesn’t help to reduce the radioactive dosage since the inside is also radioactive.) Decontamination processes could reduce the total amount of nuclear waste to around 5%.

The remaining 5% waste will be sent to a final processing place (usually we need long term management for the waste), however, this is beyond the scope of this discussion session.

2.5 Decommissioning example: Greifswald nuclear power plant

Greifswald nuclear power plant is executing the largest nuclear power plant decommissioning in the world. Greifswald is located in the north-east of Germany. Five nuclear reactors are in the decommissioning process.

In this discussion, Fukumoto picked up Greifswald nuclear plant as an example of nuclear decommissioning. This plant was granted the decommissioning permission in 1995 and started the process after that. When the plant shut down, there were 10,000 employees (and half of them were working on building new reactors). The size of company organizations in the East Germany tended to be larger than West German organizations at that time. Thus it is not simple to compare the size between the organization and a contemporary organization. For instance, after the German reunification, when the East German companies changed their system to the West German system, some of the organizations drastically downsized. After the shutdown of the Greifswald plant, some people found their job related with a new interim storage construction. Some retired according to early retirement schemes. And some of them work for the nuclear decommissioning company. Currently, 1,500 employees are working for the decommissioning company. Later, several new companies re-use the former site of the plant. Some of them are new green energy companies. Greifswald people are also working for these new companies.

The decommissioning company estimated they had finished 70% to 80% of the process in 2013. However, everything is “learning by doing” as the company’s spokeswoman said. They started the immediate dismantling for the reactor unit one, but by the time they finished the process, it turned out that the cost for the immediate dismantling was too high. This lesson learned made them change the strategy. The new plan is to use the safe enclosure method. They first store the reactor pressure vessel and the steam generator in an interim storage facility for 50 years until the level of radiation becomes low enough and then proceed to the decommissioning process. We don’t know when this process in Greifswald can be completed, but it will most likely take at least until 2045 or longer. Figure 2-1 shows the time line of the life of Greifswald reactors. The author (of this article) could not find out when they decided to use the safe enclosure method. We only know they decided after the reactor unit one is decomposed, but don’t know when it was. We could only say that it will not end before 2045. However, we could not find out how long this process will take.

The total cost of the decommissioning is not clear yet, but the current estimation of the company is 5 billion dollars (1 dollar = 100 yen).

Greifswald nuclear reactor timeline (build, run,  decommissioning). A part of data source is~[Greifswald]. x  axis represents C.E.
Figure 2-1: Greifswald nuclear reactor timeline (build, run, decommissioning).A part of data source is [Greifswald]. x axis represents C.E.

2.5.1 Decontamination process of the nuclear decommissioning

I understand that the decontamination process of decommissioning is done by cutting down the whole nuclear plant to 1m x 1m x 0.7m boxes. Then everything of the plant must be cleaned up. Literally everything, pipes, pumps, containers, walls, … are diced down to put into the boxes for the radiation inspection. If the radiation in the box is detected higher than the defined tolerance level, the box will be returned to the decontamination process again. Actually, the dimension of the box is not clearly shown, this size is rough estimate from the picture we saw in the discussion. (In the picture, a person explained about the box.) Each decontamination worker must wear a special protection suit. They must go through the decontamination process in a small chamber every time so that no radiation will be spread outside of the facility. The process is basically all manual work. All the boxes go to the low-level waste must pass the inspection test. After twenty years of the process, they still have not finished the decommissioning. The estimated current progress is 70% to 80%. Higher radioactive waste will first be kept for fifty years in a interim storage, then the decontamination process of them will start.

The life of a nuclear power plant is not finished when the plant shut down. Even a nuclear power plant closed its operation, there are remaining steps such as decommissioning. Decommissioning process provides numerous employment opportunities for a while. In the case of Greifswald, the skills and know-hows they have gathered became a strength of the city. They are also actively inviting other new businesses to the industry area where the nuclear power plant was located.

A part of the industry area has been used for factories of natural energy. The substations and the grids that were formerly used for the nuclear plant are now being re-used for the offshore wind power plant. These components are shipped to the ocean from the port that was modified from the drain of the nuclear power plant. A new gas power plant, which is under construction, has also a plan to re-use these substations and the grid.

A decommissioning process requires a large number of skilled people for decades. The city of Greifswald is hoping to grow as a pioneer and lead the decommissioning industry in and outside of Germany by using their skills and know-hows.

2.5.2 Summary of part 2

I am surprised that the decommissioning process takes at least more than 30 years. Some parts of the process first need to wait 50 years before starting the actual dismantling. Also we don’t really know how much it costs. Importantly, we don’t know who will pay for it. That depressed me. The fact that the process takes such a long time means that the people who didn’t use the electricity should pay it. And actually it is us and our children. Why should people who didn’t use the energy pay for it? This will be a burden for our descendants. I wonder if this is OK for the future of our country. In this case, parents spend the money of their children, grandchildren, and further descendants. What kind of parents do that?

This — taking money from descendants — has already been started. Some countries started to use nuclear energy earlier than Japan. For example, nuclear energy has been used from the mid-50s in U.K.. Those old reactors had already been retired. However, they started to pay the decommissioning recently. This means a large population of UK, who haven’t used the energy from these reactors, need to pay for the decommissioning. The estimated cost of decommissioning by the NDA (Nuclear Decommissioning Authority) of UK was 49 billion pound in 2010, and then the NDA adjusted the estimate to 100 billion pound in 2013 [The Guardian 2013-06-23].

On the other hand, the people of Greifswald in Germany industrialized the decommissioning process and created employment. I see they are trying to make the future. They are also expecting the big decommissioning time is coming in the world, therefore they have a plan to export their decommissioning technology to other countries. Most of the people don’t want to think about the retired nuclear reactors, therefore people are willing to pay for the decommissioning technology. Some part of me also does not want to think about the decommissioning. I think decommissioning is dangerous, time consuming, and expensive. I found Greifswald people are amazing. They have my respect. I believe I can learn something from them.

So far, we looked into the decommissioning. Now I have some information about it. Then, the next question is “what can I do for that?” Even if I can change nothing, how can I behave with this reality. I would like to think through about it. The next installment will be the last part of this article.

References

  1. [Tokyo Shinbun 2012-1-5] 東京新聞: 45年で10兆円投入.核燃サイクル事業めどなく, Tokyo Shinbun, Spent 100 billion dollars and 45 years, No chance of the establishment of nuclear fuel cycle yet. 2012-1-5. http://www.tokyo-np.co.jp/article/feature/nucerror/list/CK2012010502100003.html
  2. [Greifswald] Wikipedia En, Greifswald Nuclear Power Plant, https://en.wikipedia.org/wiki/Greifswald_Nuclear_Power_Plant
  3. [The Guardian 2013-06-23] The Guardian, UK’s nuclear clean-up programme to cost billions more than expected, 2013-06-13, http://www.theguardian.com/environment/2013/jun/23/britain-nuclear-atomic-clean-up-decommissioning

廃炉の話をしようや 1: なぜ廃炉の話なの? 廃炉って何?

2014-9-13 in Berlin, `Sayonara Nukes Berlin’ had a discussion meeting, entitled: Let’s talk about the nuclear decommissioning. We would like to report the summary of the discussion. Part one of this article outlines why we had this discussion.

1.1 Why we are interested in nuclear decommissioning

After the Fukushima Daiichi nuclear disaster, we often heard the words, “nuclear decommissioning.” We also heard about reactors reaching the end of their design lifespan, and that these reactors to be decommissioned. It’s similar to when something is broken, or not working anymore. But, it leads to the natural question: can we simply trash nuclear reactors? Can we recycle them? It seems that this is not so simple. Since any nuclear reactor has its own limited lifespan, we cannot avoid nuclear decommissioning. We, some of the members of Sayonara Nukes Berlin, just wanted to know what is it. Then, we asked Fukumoto to talk about nuclear decommissioning. Fukumoto has been following energy issues for a long time including nuclear energy problems. Fukumoto immediately answered us, “If you know about the nuclear decommissioning, you will see the nuclear energy system and its industry.” The photo below shows a shot of the discussion meeting.

Let's talk about nuclear decommissioning: meeting snapshot

 

Fig1. Let’s talk about nuclear decommissioning: meeting snapshot

 This blog article is a summary of my understanding of the discussion.

1.1.1 Lecturer: Masao Fukumoto

Fukumoto is a free journalist. He lived in East Germany (Deutsche Demokratische Republik) in the mid 80s. There was the Chernobyl nuclear incident. For him, that was an on-going disaster experience and that was the clue to follow the nuclear energy problems. He is the author of a book [Fukumoto 1] dealing with the radioactive contamination problem of Chernobyl. He is also one of the creators of a TV documentary about nuclear decommissioning [Fukumoto 2].

1.1.2 Example of nuclear decommissioning

In the discussion meeting, Fukumoto suggested to talk about Greifswald nuclear power plant as an example of a nuclear decommissioning since it is currently the largest nuclear decommissioning project in the world.

1.2 What is nuclear decommissioning?

1.2.1 Nuclear reactor and nuclear decommissioning

A nuclear reactor is fundamentally the same as a huge kettle. We generate high pressure steam by the huge kettle and drive a steam turbine to generate electricity. Since we used nuclear fuel to boil the water in the kettle, we call the resulting energy nuclear energy. This huge kettle is called a nuclear reactor. Since this nuclear reactor uses highly radioactive dangerous substances, a nuclear reactor should be processed and appropriate safety measures have to be taken before trashing it. This process is called nuclear decommissioning.

1.2.2 The start and the end of a nuclear decommissioning

A nuclear decommissioning is a process to restore the site’s “greenfield” status. Radioactivity surveillance for the area should not be required after the decommissioning. However, a nuclear decommissioning is only of the cleanup. Nuclear decommissioning produces radioactive waste and processing radioactive waste was beyond the scope of the meeting. We may have another discussion meeting for the topic.

When the area is back to a greenfield status, then that is the end of nuclear decommissioning. So, when does a nuclear decommissioning start?

The nuclear decommissioning started in the design phase of the plant and the reactor. To make the decommissioning process safe, we need to design a reactor that can be safely decomposed. For instance, we need to build a reactor that can be carried by a crane (or by some kind of machine) to remove it from the building. Otherwise the process would become difficult.

In Germany today, the government cannot give permission to build a reactor if the designer of the reactor didn’t consider the concept of nuclear decommissioning (East Germany (Deutsche Demokratische Republik) might not have had this regulation.) However, including the decommissioning concept in the reactor design seems not necessary to build a reactor in Japan (Recorder’s footnote: [NHK special document 2009.10.11] shows that a Japanese company lost some of the design plan of their reactor, and the remaining design plan is too old to read it. The regulations didn’t require to keep the plans.)

1.3 The methods of nuclear decommissioning

There are mainly two methods of nuclear decommissioning:

  1. Immediate dismantling
  2. Safe enclosure (Sometimes this method is further divided into Safe enclosure and Entombment.)

Let’s see them one by one.

 1.3.1 Immediate dismantling method

This method starts decomposing the reactor directory after the power plant shuts down. The pros and cons of this method are:

  • Pros: There still are the workers who know the plant details. This is an advantage for the decomposing operation.
  • Cons: The radioactive contamination level is high

Nuclear reactors are not standardized. Each plant is highly customized. Therefore, availability of the workers who know the plant is an advantage to operate the decommission.

On the other hand, immediately after the shutdown of the reactor, the radioactive dosage is still high. This makes the decommissioning operation difficult. We need to develop some kind of technology, for instance, using a special robot.

1.3.2 Safe enclosure method

This method first keeps the reactor in storage and waits for some period (it is usually more than 30 years). The pros and cons of this method are:

  • Pros: The radioactive dosage is relatively low when operating the decommission
  • Cons: The workers who know the plant details are no longer available

The process is relatively easier than the immediate dismantling method since the radioactive dosage will be relatively low. But we can never completely remove the radioactive contamination in several decades, the difficulty is only relatively lower.

On the other hand, this method needs more than thirty to fifty years of storage time, we usually cannot expect the help from the workers who know the plant details.

1.4 Part 1 Summary

Everything on the earth has a limited lifetime. A nuclear reactor is not an exception. However, I haven’t heard what happens when a reactor reaches the end of its design lifespan. I can easily imagine that we cannot trash it like a piece of paper.

In this article, we talk about what is a nuclear decommissioning and how could we do that. My main concern is actually “Is it really possible and how?”, “How much does it cost? Who pays that?”, and “What should we do about the nuclear waste?” The first question has been answered in this article: It might be possible, but it is difficult.

Before the Fukushima disaster, I was less concerned about the energy problem. I simply thought, “Anyone should have thought through it.” However, what we saw in the Fukushima disaster was “No one thought about it.” and “No one wants to take responsibility.” The responsible people told us, “it’s unexpected.” One of the strangest logic was that “It’s unexpected, therefore no one takes responsibility. It is a natural disaster.” I can hardly understand that a nuclear reactor explosion is a natural disaster. I personally thought, I don’t want to die with the reason of “unexpected.” The Fukushima disaster opened my eyes, it said “Hey you, wake up!” But I don’t know what I can do about this. Maybe it is better if I keep sleeping, ignoring the Fukushima disaster. However, I also know that if everyone keeps sleeping, the next disaster is unavoidable. Whether I am ignoring the problem or not, Japan has around 60 nuclear reactors. That fact always remains. I asked myself, “Why did this happen to us?” A part of me still wants to go back to be a person who doesn’t think about this problem. On the other hand, I cannot stop thinking what Fukushima really means: What does it mean to use an energy source that forces us to lose a part of our country? What does it mean to use air conditioning and to access the internet powered by nuclear reactors which endanger the life of people, especially children’s lives.

Then, what can I do about it? Maybe I can do nothing. I still would like to ignore the problem since thinking is hard. However, I also said to myself, “If I cannot change anything, does it really matter? It isn’t hard to try to think about this problem. If I can achieve something, that’s pure luck, but if not, so what?” So I started researching the energy problem. It’s fine even if I can only understand just a part of it. I just don’t want to hear the excuse again, “Sorry, that is a unexpected natural disaster, we can do nothing for you.”

In part two of this article, I would like to look into my next questions, “How much does the nuclear decommissioning cost, and how long does it take?”, “What should we do with the nuclear waste?”

References

  1. [Fukumoto 1] ふくもと まさお, “ドイツ・低線量被曝から28年 –チェルノブイリはおわっていない”, 言叢社, 2014 (Masao Fukumoto, “Germany, 28 years after the low level dosage exposure — Chernobyl has not been ended”, Gensou publishers, 2014, ISBN-13: 978-4862090478)
  2. [Fukumoto 2] 日本テレビ, NNNドキュメント’13, 活断層と原発、そして廃炉, http://www.ntv.co.jp/document/news41_2.html, 2013 (Japan TV, NNN document’13, Active fault, nuclear power plant, and nuclear decommission, http://www.ntv.co.jp/document/news41_2.html, 2013)
  3. [NHK special document 2009.10.11] NHK スペシャル 2009.10.11, 原発解体~世界の現場は警告する~ http://www.nhk.or.jp/special/detail/2009/1011/ (NHK Special, Decompose the nuclear plants: the field of the world warns us, http://www.nhk.or.jp/special/detail/2009/1011/)