The Japan Nuclear Waste Management Organization (NUMO) has begun an initial phase of assessing two municipalities in Hokkaido Prefecture for their suitability to host a final disposal facility for high-level radioactive waste (HLW).

First-stage surveys began on 17 November. This is the first time such preliminary studies have been conducted in Japan. NUMO said it had received the necessary permission from the Ministry of Economy, Trade and Industry (METI) to conduct  “information research” in the towns of Suttsu and Kamoenai.

“We are starting by collecting and organising the necessary documents and data, such as geological maps and academic papers,” the statement said. NUMO will spend about two years testing geographic layers and bedrock strength in the municipalities based on geological maps and scientific papers. Based on the results of the first phase, possible locations will be selected for the second phase of the study. This scoping study will include drilling over a four-year period to analyse the geographic layers. At the third stage, a test bench will be built.

“The briefing is intended to deepen understanding of the state of potential geological disposal in municipalities by studying and analysing literature and data on the geology of the municipalities that have shown interest, and is part of the dialogue activities,” NUMO said.

NUMO will need permission from the governor of the prefecture to move to the second phase. However, Hokkaido Governor Naomichi Suzuki has issued a statement opposing the process, citing a Hokkaido ruling that said no radioactive waste should be taken to Japan's main northern island.

In 2002, NUMO asked municipalities across Japan to apply to consider siting radioactive waste disposal facilities. In 2007, Toyo City in Kochi Prefecture applied, but later withdrew its application. No other municipalities showed interest. Japan adopted a new basic policy for the final disposal of HLW in 2015. It included a decision to study the scientific characteristics of regions countrywide.

In July 2017, METI issued a “scientific performance map” for the HLW geological disposal showing the regions likely to meet the necessary geological requirements that may be included in a future detailed site selection study. The government offered grants of up to JPY2 billion ($19 million) to applicant municipalities in a first phase.

In October, Suttsu and Kamoenai, which are both struggling with depopulation, decided to apply for the literature survey  and will therefore each receive up state subsidies in exchange for their participation.