Reprocessing plant for spent nuclear fuel Aomori has many challenges for full-scale operation

Reprocessing plant for spent nuclear fuel There are many challenges to full-scale operation Aomori May 13 15:13

Regarding the facilities that are essential to the “nuclear fuel cycle policy” promoted by the government, and the reprocessing plant in Aomori Prefecture, the Nuclear Regulation Authority has issued a draft examination document that shows that the measures against accidents, etc. comply with the new regulatory standards, and that they actually pass. I put together on the day. However, full-scale operation requires a local understanding, etc., and it is also necessary to clarify where to use the plutonium to be extracted, which poses many challenges.

The core of the nuclear fuel cycle

The reprocessing plant in Rokkasho Village, Aomori Prefecture, is Japan's first commercial facility to extract plutonium from spent nuclear fuel from nuclear power plants in various regions.

Since plutonium can be processed again into nuclear fuel and used at nuclear power plants, Japan, which is poor in fossil fuels such as oil, decided to introduce a nuclear power plant in order to repeatedly use nuclear fuel for a stable energy supply. We have been planning to use plutonium since the 1980s.

This policy is called the “nuclear fuel cycle policy” because it recycles nuclear fuel and uses it repeatedly, and the reprocessing plant that takes out plutonium is a core facility. However, the reality is that this policy has not progressed as originally planned.

Fuel destination, "Fast Reactor" development

The first is the problem of the development of a special nuclear power plant called a "fast reactor" which was supposed to mainly use plutonium taken out at the reprocessing plant. Since a fast reactor has the ability to generate more plutonium than it used while generating electricity, it was being developed as a “dream reactor”. However, in the middle of its research, the corporation in the country of the business caused repeated troubles with "Monju" created in Tsuruga City, Fukui Prefecture, the cost increased, and almost four years ago (2016), the government monju Decided to decommission and lost a big foothold for domestic development.

So, instead of "Monju", the country decided to accumulate technology by cooperating with the development of a new type fast reactor planned by France, but France also showed a policy to suspend construction of a new fast reactor last year (2019), The future of fast reactor development is uncertain.

Another cycle, "Pull thermal"

As another destination for plutonium, we are proceeding with power generation called "Pluthermal" which is mixed with normal uranium fuel and reused at ordinary nuclear power plants, but this is not progressing as originally planned.

Before the accident at the Fukushima Daiichi Nuclear Power Plant, electric power companies were planning to implement pull-thermal power generation from 16 to 18 nuclear power plants nationwide by 2015, but it is now possible to implement pull-thermal power generation in Fukui Prefecture. There are only 4 units at Takahama Nuclear Power Plant Units 3 and 4, Ikata Nuclear Power Plant Unit 3 in Ehime Prefecture, and Genkai Nuclear Power Plant Unit 3 in Saga Prefecture.

Other facilities required for policy are yet to be determined

Moreover, even if the reprocessing plant operates, the objective of the policy of effectively utilizing nuclear fuel and efficiently promoting energy supply cannot be achieved. Because other related facilities are needed. For example, if you try to recycle plutonium twice, the composition of the nuclear fuel will change, so you will need a factory called the "second reprocessing factory" different from the current reprocessing factory. However, despite the concept of the second reprocessing plant, the basic plan is not currently made.

At the beginning, the construction cost of the reprocessing plant was 760 billion yen, but due to repeated troubles, postponement of construction, and costs for safety measures, the cost has finally expanded to nearly 3 trillion yen. The total project cost, including expenses for operation and abolition, is expected to reach 13,940 billion yen. It is also pointed out that an enormous budget will be required in the future, considering the construction of related facilities.

The problem of excess plutonium

It is also an international commitment to clearly indicate where to use the plutonium to be extracted. Since plutonium also serves as a material for nuclear weapons, it is a principle that each country does not have excess plutonium for which there is no purpose. Japan has also made an international commitment to this and is also called the "nuclear guard", the IAEA = International Atomic Energy Agency. We are accepting the inspection. However, Japan already owns around 46 tons of plutonium at home and abroad as of the end of 2018. According to experts, it is a large amount in the countries other than the nuclear-weapon states. If the reprocessing plant starts operation in the future, it will be able to take out up to 7 tons of plutonium per year, but if the usage destination is not clarified, there is a risk of increasing concerns of the international community.