Several countries have shown interest in alternative disposal method, says agency

In deep borehole disposal, radioactive waste is placed in a single deep borehole drilled vertically into the Earth’s crust. Courtesy IAEA.

A project to support research into deep borehole disposal for intermediate and high-level radioactive waste will help create the groundwork for a potential large-scale demonstration project, the International Atomic Energy Agency said.

The project, which is open for research proposals, is aimed at extending scientific and technical groundwork that validates the safety and practicality of the deep borehole concept, the IAEA said.

The IAEA said it had launched the project in response to interest expressed by several countries – for example Australia, Croatia, Denmark, Norway and Slovenia – in exploring whether deep borehole disposal might provide a suitable option for disposal of their specific inventory of radioactive waste.

“The primary motivation is to develop a more cost-effective disposal approach, without jeopardising safety,” the agency said. “Further studies on the concept can build on decades of prior desktop studies conducted in countries such as the UK and the US, as well as on some recently conducted scoping studies.”

The conventional approach to underground disposal involves burial within excavated deep geological repositories within the Earth’s bedrock. Nations that operate nuclear reactors for power generation, medical radioisotope production, research purposes or other applications are mandated to establish geological disposal solutions for spent nuclear fuel and radioactive waste.

In typical deep geological repository designs, waste is placed in engineered containers within the repository’s tunnels and rooms and the entire structure features multiple barriers to prevent the release of waste into the environment.

The repository is sealed and backfilled, and long-term monitoring carried out to ensure the integrity of the containment system and to detect any potential leaks or breaches.

Cost And Potential Are Driving Research

These repositories are designed to accommodate larger quantities of waste and are intended to serve as long-term solutions for the disposal of hazardous materials. However, their cost and the potential of new technologies that enable other possible solutions are driving investigation into alternatives like deep borehole disposal.

Finland is set to implement the world’s first deep geological repository and several other countries are working on programmes to build one.

In deep borehole disposal, radioactive waste is placed in a single deep borehole that is drilled vertically into the Earth’s crust, often reaching several kilometres in depth. The waste is typically placed in canisters or containers, which are then lowered into the borehole to a predetermined depth within a stable geological formation.

Deep borehole disposal is primarily being considered for relatively small quantities of waste and can be suitable for certain types of high-level radioactive waste or other hazardous materials.

The central concept behind the approach is to isolate the radioactive waste at significant depths within a stable environment, preventing its release indefinitely. The borehole is sealed and monitored to ensure the waste remains contained and isolated.

Stefan Mayer, a specialist in radioactive waste disposal at the IAEA, said “several countries want to find out if deep borehole disposal would be suitable for their specific waste inventories,” and that “the conceptual studies and generic assessments done so far look promising”.

Date: Tuesday, 29 August 2023
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