Oslo, Norway, July 1st, 2013. The trial-operation of a thorium based nuclear fuel has commenced in Norway. An international consortium led by Thor Energy is undertaking a sophisticated test-irradiation campaign in order to quantify the performance of the fuel and to qualify it for commercial use. The first thorium fuel specimens have been loaded into the materials test reactor operated by the Institute for Energy Technology in Halden, Norway. The Norwegian Research Council is a major backer for this project.
“A major milestone has been reached with the loading of the thorium fuel rig into the Halden test reactor” said Øystein Asphjell, CEO of Thor Energy. “This is the beginning of a new era – not only for our company and our partners; Westinghouse, Fortum (Finland) and the UK’s National Nuclear Laboratory, but as an important evolutionary step in fuelling the nuclear power industry. Our fuel will move us toward a more sustainable nuclear power industry” Mr. Asphjell said.
Thor Energy has been undertaking detailed thorium fuel strategy studies since 2006 – this is a complex subject area involving reactor physics, material science, energy economics and international relations. Collectively, these studies demonstrate that thorium fuels incorporating recycled plutonium are viable in terms of economics, waste management benefits and operational advantages. Importantly, these thorium-plutonium fuels can operate in new and existing light water reactors (LWRs), so new generating infrastructure is not required.
Thorium is not fissile – but ‘fertile’. In order to create a reactive thorium fuel capable of producing energy, some fresh or recycled fissile material is needed as a ‘driver component’. As the fuel operates, thorium transmutes into a fissile material that then yields energy in the fuel. Reactor-grade plutonium is a very good fissile driver. Furthermore, it is available from today’s spent nuclear fuel. Indeed, thorium-plutonium fuel can serve to reduce inventories of this material.
Thorium oxide based fuels have advantageous material properties such as higher thermal conductivity and higher melting point – properties that lend safety margin benefits. Thorium fuels can produce less long-lived waste and they generate no new plutonium. Furthermore, they will help diversify fuel supply options for the nuclear sector.
The five year irradiation campaign will produce a large amount of unique data that describes how the thorium fuel ceramic behaves as it operates for long periods in a reactor core in various conditions. A specially designed fuel rig holds six instrumented test rods containing three different thorium fuel mixtures. The Halden test reactor allows for continuous data collection while the fuel operates in simulated LWR conditions.
Promising temperature readings have already been acquired from these first thorium fuel pellets. Test data such as this will support computer modeling efforts. Follow-on tests in a commercial power reactor are anticipated.