AS MORE SPENT FUEL IS sent for final disposal, the importance of reliable safeguarding of nuclear materials increases. Using a distributed ledger technology (‘blockchain’), information on nuclear materials could be maintained unchanged far into the future.
Earlier this year, Finland’s Radiation and Nuclear Safety Authority (Stuk), the US-based Henry L Stimson Center and the University of New South Wales in Australia outlined the opportunities presented by blockchain technology for keeping nuclear material records and for safeguarding of nuclear materials.
“The purpose of the Slafka system, which is currently in the piloting phase, is to investigate whether blockchain is a solution to problems related to the long-term retention and processing of data in nuclear material records,” says Stuk.
Pursuant to the Non-Profilation Treaty (NPT), the International Atomic Energy Agency (IAEA) supervises states to ensure they have no unreported nuclear materials and that nuclear materials remain in peaceful use. This is assured through audits and nuclear material records, which are verified through measurements.
National authorities (including Stuk) and operators submit the required reports on the use of nuclear materials to the IAEA and the European Commission.
“In the existing model, nuclear material records are based on electronic documents that involve common problems: version management, data correctness and information security call for special attention,” says Elina Martikka, international cooperation manager at Stuk.
“With blockchain technology, register data could be available to the authorities correct and unchanged. This would also improve the efficiency of international nuclear material supervision processes,” she adds.
Final disposal of nuclear waste introduces new challenges in the safeguards sphere, Martikka notes.
Slakfa is a pilot solution based on Stuk’s current nuclear accounting database, Safka. It will test and demonstrate user interactions and development ideas in a DLT-based reporting system. The demonstration will introduce operators and Stuk to the technology without compromising real data and can be employed by Stuk for role-playing, strategy games and training.
Finland is an interesting pilot area for keeping nuclear material records based on blockchain technology, as Posiva is building a final disposal facility for spent nuclear fuel at Eurajoki near the Olkiluoto nuclear power plant. It is expected to be the first facility of its kind in the world.
In 2019, Posiva’s final disposal project entered a new stage – implementation – when the Board of Directors took a decision to begin construction of the encapsulation plant and the underground repository for spent fuel.
Work progressed to plan and the foundation stone of the encapsulation plant was laid in September 2019. The objective is to start safe final disposal in the repository, to be named Onkalo, in the mid-2020s, Janne Mokka, chief executive of Posiva says in the company’s latest annual report, released in April.
Spent fuel will be packed inside copper-steel canisters at the encapsulation plant before being transferred into the underground tunnels of the repository at a depth of 400-450 metres, and placed in deposition holes lined with a bentonite buffer.
Martikka says: “When spent nuclear fuel is placed at a depth of almost 500 metres inside the bedrock and the tunnels are closed, it is no longer possible to secure the material physically. This emphasises the importance of the integrity and retention of nuclear material records, an issue now to be addressed with blockchain technology.”
A report on the Slafka is expected in August 2020.
