The mayor of Tsushima in southwestern Japan said Wednesday he has decided against applying to the state for a preliminary survey to gauge the island city's suitability to host an underground disposal site for highly radioactive waste from nuclear power generation.

The decision comes in contrast with the local assembly's approval earlier this month of a request filed by proponents urging the city to accept the survey.

"There is insufficient consensus among the public," Mayor Naoki Hitakatsu said at a city assembly session, with some fearing the potential impact on tourism and primary industries such as fisheries.

He later told reporters he also has concerns about reputational damage that may arise from conducting the survey.

Tsushima Mayor Naoki Hitakatsu takes part in a city assembly session on Sept. 27, 2023 in Tsushima, Nagasaki Prefecture. (Kyodo)

The preliminary survey is the first step in a three-stage process spanning two decades to select a permanent disposal site for nuclear waste. Struggling to find one, the central government is looking for municipalities willing to accept the survey, but only two municipalities in Hokkaido have so far done so.

Tsushima, on a remote island in Nagasaki Prefecture, was identified as a potential disposal site on a map of such locations released by the central government in 2017.

Hitakatsu has raised worries about hosting such a site, saying, "The risks that may arise from unperceived factors cannot be ruled out."

Opponents of the plan have also said it would not be appropriate for the city to host a disposal site for nuclear waste given the history of the U.S. atomic bombing of Nagasaki city in 1945.

Local construction groups and other proponents argued that state subsidies of 2 billion yen ($13.4 million) for accepting the survey could be used for measures to rev up the shrinking city's economy and support child-rearing.

The mayor, who may seek a third four-year term after his current term expires in March, told a press conference that the reputational damage that may arise from carrying out the survey "cannot be covered by a subsidy of 2 billion yen."

He also said he "judged it would become difficult to reject" the subsequent geological research if the preliminary survey showed that the city is suited as a site for the final disposal of nuclear waste.

The surveys, conducted by the Nuclear Waste Management Organization, a quasi-government body in Tokyo, involve checking land conditions and volcanic activity based on published geological sources.

Following Tsushima's decision, the central government said it will continue efforts to find more areas to carry out preliminary surveys.

"We are very grateful that Tsushima showed interest and had considered" accepting the survey, said Chief Cabinet Secretary Hirokazu Matsuno at a press conference.

Fast-aging Tsushima, where the number of residents fell below 30,000 in 2020, depends on squid fishing and pearl farming but is struggling to find young people to carry on the running of its industries.

It is located closer to the South Korean port city of Busan, 50 kilometers away, than any major Japanese cities.

High-level radioactive waste, produced when extracting uranium and plutonium from spent fuel, must be stored in bedrock at least 300 meters underground for tens of thousands of years until the radioactivity declines to levels that pose no harm to human health or the environment.

Japan, like many other countries with nuclear plants, is struggling to find a site for such disposal.

Related coverage:

1st round of treated water release off Fukushima plant completed

Residents file suit to halt wastewater release from Fukushima plant

Radiation level of seawater off Fukushima below limits: Japan gov't