(Let’s learn the Temporary Incineration/Ash Treatment Facility) What is the Interim Storage Facility? (Vol. 3)

Reference: Interim Storage Facility Information Center (The Temporary Incineration Facility and the Temporary Ash Treatment Facility in the Futaba Construction Section)

Hello, everyone. My name is Daichi, an expert providing the information on the radiation issues in an easy-to-understand manner.

So far in the previous articles, the overview of the Interim Storage Facility was covered in this article, and in this article, individual facility, especially the Soil Separation Facility, as well as the Soil Storage Facility were elaborated.

As a continuous work, this article covers the Temporary Incineration Facility, the Temporary Ash Treatment Facility, the Waste Storage Facility, as well as other kinds of facilities.

In other words, this article responds to the following questions:https://radiation-pub.com/wp-admin/edit.php

– What is the Temporary Incineration Facility?
– What is the Temporary Ash Treatment Facility?
– What is the Waste Storage Facility?
– What kind of other facilities are there in the premise of the Interim Storage Facility?

Table of contents of this article

I have been involved with the radiation-relevant issues, like the policy on the decontamination activities and the management of the Interim Storage Facility, after the accident of the Fukushima Daiichi Nuclear Power Plant in 2011.

I received a doctorate in the field of radiation, while working in Fukushima.

(Let’s learn the Temporary Incineration/Ash Treatment Facility) What is the Interim Storage Facility? (Vol. 3)

As covered in this article, there are the Temporary Incineration Facility, the Temporary Ash Treatment Facility and the Waste Storage Facility, which temporarily stores fly ash generated in the Temporary Ash Treatment Facility.

Each facility will be elaborated in the following parts of this article.

Temporary Incineration Facility and Temporary Ash Treatment Facility

The above figure represents treatment procedures of burnable waste arising from decontamination activities and resulting ash.

With regard to the Temporary Incineration Facility, in the premise of the Interim Storage Facility, there is one facility in Okuma Town, and there are two facilities in Futaba Town.

Types of furnaces are different with each other: a furnace of the facility in Okuma Town and a furnace of the facility (of the 2 facilities) in Futaba Town are stoker furnaces, and the of the other facility in Futaba Town is shaft furnace.

In the Temporary Incineration Facility in the premise of the Interim Storage Facility, burnables like leaves and twigs are incinerated and resulting ash is transported into the Temporary Ash Treatment Facility.

To be exact, ash accumulated at the bottom of the facility is called ‘bottom ash’, and ash captured in the dust collector is called ‘fly ash’, and both of them are treated in the Temporary Ash Treatment Facility.

In the shaft furnace, bottom ash is not generated, but instead slag is directly generated.

In the Temporary Ash Treatment Facilities, the one facility is equipped with the rotating melting furnace, and the other is equipped with the coke-bed furnace.

Both furnaces melt ash under the very high temperature to generate slags, and during the processes metals are collected using magnetic separators.

Ash generated both outside and inside the premise of the Interim Storage Facility are transported into the Temporary Ash Treatment Facility for their treatment.

Dust collectors are also equipped in the Temporary Ash Treatment Facility and captured fly ash is stored in the Waste Storage Facility mentioned below.

In both the Temporary Incineration Facility and the Temporary Ash Treatment Facility, continuous monitoring equipments monitor the radioactivity concentration of radioactive cesium released into the atmosphere, 24/7 in the stacks to ensure its safety.

Waste Storage Facility

　There are 2 Waste Storage Facilities in Okuma Town, and 2 Facilities in Futaba Town, and as described in the above figure, they store fly ash generated in the Temporary Ash Treatment Facilities.

As a result of treatments in the Temporary Incineration Facility and the Temporary Ash Treatment Facility, volume of waste with radioactive materials is drastically reduced and it becomes much easier to be managed, but it is highly concentrated and radioactivity concentration becomes much higher.

The radioactivity concentration sometimes becomes a couple of tens/hundreds of thousands of becquerel per kilogram, so the waste is stored in special steel containers and they are piled up in around 3-4 layers, in concrete buildings with walls of 30cm-thick, to prevent radiation from affecting surrounding environment.

This is the current end-state for burnables, whose volume is utmost reduced, and further treatment procedures for waste stored in the Waste Storage Facilities are currently under consideration.

Specifically, a demonstration project for technology development for washing fly ash is currently implemented.

This is the technology seeking for concentration and stabilization of radioactive cesium, taking advantage of its characteristic: it firmly attaches to soil particles, both physically and electrically, but on the other hand it doesn’t firmly attach to fly ash and relatively soluble to water.

As aforementioned, if it is more concentrated, radioactivity concentration gets higher, but instead it becomes much easier to be managed, because its volume becomes much smaller.

Concentration level is supposed to be considered, taking account of a lot of factors, including cost, time and subsequent treatment methodologies.

Other Facilities

So far almost all of the major facilities in the premise of the Interim Storage Facility have been covered, but there are other following facilities in the premise.

Waiting Space

The amount of transportation to the Interim Storage Facility hit the peak around in Fiscal Years 2019 and 2020, and at that time every year around 4 million m³ of removed soil and waste were transported into the Interim Storage Facility.

The number of trucks coming into the premise of the Interim Storage Facility was around 3,000 per day and there were long queues at the Storage Places and the Soil Separation Facilities to unload the container bags.

The Waiting Spaces were constructed for the trucks waiting for their turn.

After that the amount of transportation has decreased to around 2.4 million m³ (Fiscal Year 2021) and around 800 thousand m3 (Fiscal Year 2022), and no long queues can been seen at the Waiting Spaces anymore.

Screening Facility

There are a couple of Screening Facilities in the premise of the Interim Storage Facility,　because radiation level of all vehicles in the Interim Storage Facility needs to be examined before their exit.

Based on Ordinance on Prevention of Ionizing Radiation Hazards at Works to Decontaminate Soil and Waste Contaminated by Radioactive Materials Resulting from the Great East Japan Earthquake and Related Works (in Japanese), they are allowed to exit from the Interim Storage Facility, by ensuring the count number of GM　(Geiger–Müller) counter is less than 13,000 cpm (count per minute).

Technology Demonstration Facility

It will be elaborated in detail in another article, but as briefly touched upon in this article, the removed soil currently stored in the Interim Storage Facility is subject to final disposal outside the Fukushima Prefecture by March 2045, and technology development for volume reduction and recycling is currently promoted, to reduce the volume for final disposal as much as possible.

In the premise of the Interim Storage Facility, the Technology Demonstration Facilities have been already constructed: a facility for the demonstrative projects, by advertising private companies and other organizations for ideas of the technologies for the safety and stability of recycling of removed soil, and a facility for demonstrative projects for adsorption and stabilization of radioactive cesium, dissolved in water by washing fly ash, generated in the Temporary Ash Treatment Facility.

Information Center

To be exact, it is located outside the premise of the Interim Storage Facility, but there is a Interim Storage Facility Information Center to disseminate the information about the Interim Storage Facility.

It seems that, the Information Center provides tours periodically to see the Interim Storage Facility on-site, so you could participate in the tour, if you are interested in.

Summary

This article briefly introduces the rest of the facilities in the Interim Storage Facility: the Temporary Incineration Facility, the Temporary Ash Treatment Facility and the Waste Storage Facility, as well as other facilities: the Waiting Space, the Screening Facility, the Technology Demonstration Facility and the Information Center.

By the way, above-mentioned contents are summarized in the following videos.

It would be appreciated to visit them at your convenience.

– Japanese version

– English version

You can read the same article in Japanese here.

Thank you very much for reading this article.

See you next time!