A leading British nuclear expert has raised concerns about the safety of Russia’s floating nuclear unit.
The world’s first floating nuclear power plant, the Academik Lomonosov, left its shipyard in St Petersburg last week after 10 years in construction.
Developed by the Russian state atomic energy firm Rosatom, the vessel is set to travel 5,264km to Pevek in eastern Russia.
But concerns about the safety of the plant have emerged, with Greenpeace labelling the vessel a “floating Chernobyl”.
Consultant National Nuclear Laboratory’s external relations director Adrian Bull told New Civil Engineer that emergency procedures for a floating nuclear vessel would have to be different to those for land-based plants. He has previously worked as an engineer for Moorside nuclear reactor designers Westinghouse.
Bull explained that in an emergency at a nuclear plant, a reactor core would take days to cool even after it had been shut down. The reactor must be cooled without letting any radiation leak into the environment.
“You want to keep the containment barrier but lose the heat, that’s the challenge,” he said.
Many modern land-based reactors have passive safety systems that partly rely on gravity to remove the heat using a coolant such as water or air without electricity over a period of several days.
“You can lose all of the electricity supply for a [land-based] reactor and the natural circulation and gravity will make sure enough of the heat is dissipated by circulating that coolant around,” said Bull.
But he said that if a floating nuclear plant sank, a different cooling method would be needed.
“Obviously you can’t rely on something like gravity on a ship-based reactor because if it were to sink, the orientation of the reactor might not be the same as it is on the surface. It could tilt or overturn during that process.
“It raises other challenges that maybe don’t apply to a land-based reactor. You can kind of assume that on a land-based reactor it’s not suddenly going to turn through 180°.”
Even without using a gravitational safety system, Bull said procedures to tackle an emergency on a water-based nuclear power plant would face extra safety challenges.
He added: “You want to make sure that not only have you got a coolant there to take the heat away, you’ve also got the ability to circulate that coolant, so you’re looking at wanting to make sure you’ve got pumps that are operational and so on – that’s obviously easier above ground than if all of that infrastructure is suddenly below the water surface. You’d have to ensure that the safety systems were suitably robust to deal with that.”
Rosatom stressed that processes on the floating nuclear power plant have met International Atomic Energy Agency safety criteria, adding the plant is “designed with the great margin of safety that exceeds all possible threats and makes nuclear reactors invincible for tsunamis and other natural disasters”.
When Academik Lomonosov has been loaded with fuel and powered up in 2019, the 140MW plant – which has two KLT-40S reactor units on board – will be used to power industrial plants and port cities in Russia’s hard-to-reach northern and eastern areas.
The plant could also be used as a desalination plant for salt water, providing up to 240,000t of potable water each day.
It is the first in a series of floating nuclear plants which Russia wants to put into mass production, according to Russian news outlet Russia Today. The station also said 15 countries, including China, have expressed interest in developing floating nuclear plants.