A whole host of operators are still carrying out full-scale decontamination in the village of Iitate and the city of Minamisoma. For our part, we are continuing to provide services such as post-decontamination radiation monitoring.
Now that decontamination has been completed in certain areas, we have been commissioned by the Ministry of the Environment to carry out post-decontamination monitoring, to measure levels of radiation based on the required level for people to return to their homes.
As part of measures to deal with designated waste* held by local authorities, we are also working to stabilize processing in order to prevent dispersal or leaks, reduce air dose rates, and minimize levels of dissolved radioactive cesium. We have also been working to solidify approximately 3,000 tons incinerated fly ash into cement at the Nanbu Waste Disposal Center in Iwaki since April 2014. We had planned to finish by March 2015. Having confirmed the presence of difficult-to-treat fly ash however, we extended the construction period as part of this project and completed solidification processing at the end of May.
We have also launched a pilot project to transport contaminated soil and other selected materials that have been moved as a result of decontamination work to interim storage facilities. We intend to continue developing technology for the treatment and disposal of contaminated soil and other such materials, as well as offering adequate processing solutions with an eye to final disposal.
* Designated waste refers to waste exceeding 8,000 Bq/kg, as designated by the Minister of the Environment.
In response to requests from local governments, we had been taking in and processing disaster waste in the wake of the Great East Japan Earthquake. We safely and steadily processed disaster waste confirmed as safe at our three plants in Iwate, Aomori and Yokoze, based on the understanding of local residents, etc. We finished accepting disaster waste in March 2014 and, in total, we processed around 88,000 tons of waste.
In March 2014, both our Aomori and Yokoze Plants received a letter of thanks from the Minister of the Environment in recognition of their commitment to wide-area processing of disaster waste (processing outside of the affected prefectures). We will continue to supply cement as a basic material in these areas in an effort to assist in reconstruction.
Our acceptance of disaster waste (as of March 2014)
types of waste
|Since October 2011||Waste wood, waste plastics, combustibles and incombustibles||71,817t|
(Yokozemachi, Chichibu-gun, Saitama prefecture)
|From September to December 2012||Waste wood||490t|
(Higashidorimura, Shimokita-gun, Aomori prefecture)
|From October 2012||Combustibles and incombustibles||16,118t|
We are facilitating the use of copper slag, a by-product of the copper smelting process, in concrete fine aggregates, with the aim of preserving natural concrete aggregates and reducing the destruction of mountain forests.
Our group company Onahama Smelting & Refining Co., Ltd. (Iwaki city in Fukushima Prefecture) is now able to produce copper slag fine aggregate CUS2.5 (JIS standards) that can be used alone after introducing industrial waste grinders and adjusting optimum granularity. As a result, copper slag is expected to become more widely used as concrete fine aggregate. We registered this technology under the name “copper slag fine aggregate for heavy concrete” in the New Technology Information System (NETIS). This registration is expected to promote its use in public works projects at ports, etc. where heavy concrete is required for persistent structures.
Already, as part of disaster recovery efforts, heavy concrete using copper slag fine aggregate (using CUS2.5 alone) has been used in breakwater and port construction in Fukushima Prefecture. We are working to promote use, checking that there are no problems with quality and construction constraints by conducting wide range of experiments prior to actual construction.
In the future, we plan to expand sales of copper slag both in East and West Japan, to help save resources and energy.