By Susan Curtis at the APS March Meeting in Dallas
Harold Macmillan, British Prime Minister from 1956 to 1963, once famously said that the biggest challenge facing politicians was “Events, dear boy, events”. Little did the American Physical Society (APS) know that those same words would apply to session H5, entitled “Drowning in carbon: the imperative of nuclear power”, when it was conceived some nine months ago.
Unsurprisingly, the events at the Fukushima Daiichi nuclear reactor in Japan reverberated through the entire session. Most telling was that Toshikazu Suzuki of Japan’s National Institute of Radiological Sciences, who had been due to speak on the country’s nuclear programme, was unable to attend because of his responsibilities in Japan.
Other speakers and commentators focused on the partial meltdown at Fukushima, as well as the impact that such a serious incident will have on nuclear-power programmes in other parts of the world. Ray Orbach, former under-secretary for science at the US Department of Energy and now director of the Energy Institute at the University of Texas at Austin, had originally planned to talk about the disposal of spent nuclear fuel, but instead gave a detailed commentary on the damage sustained by the Fukushima reactor and lessons for similar reactors in other parts of the world.
According to Orbach, the reactor shut down safely immediately after the earthquake, but it was the subsequent tsunami that caused the emergency power generators to fail – and with them the water-based cooling system used to store spent nuclear fuel rods. But he questioned why it took more than two days for the reactor’s operator, the Tokyo Electric Power Company (TEPCO), to start injecting seawater into the core to stop the fuel rods from overheating.
“Why did they wait so long?” he asked. “Well of course you ruin the reactor when you do it. It’s also a question of the power company not wanting to admit that all else has failed.”
TEPCO was also criticized for keeping a large inventory of spent fuel rods in cooling ponds on the reactor site. Fuel rods are normally water-cooled for a number of years before being transferred to dry concrete casks for off-site storage, but at Fukushima the number of spent fuel rods in the cooling ponds had accumulated because of delays in building an off-site reprocessing facility.
Despite these issues, Orbach offered some technical solutions to improve safety at similar reactors in other parts of the world. Top of the list is to introduce passive cooling for spent fuel storage ponds, which would be unaffected by any disruption to the power supply.
That theme was picked up by Robert Rosner of the University of Chicago, who was also director of the Argonne National Laboratory from 2005 to 2009. Rosner argued that the US has reached a pivotal time in its use of nuclear energy. There are currently 104 nuclear power plants operating in the US, but there have been no new starts since 1977 – largely because of public concern over safety.
“We need to choose whether to only focus on regulation – or even stop nuclear altogether – or to spend some money to identify and fix the safety problems,” he told the meeting. With US funding for energy research falling, and an even more suspicious public in the wake of Fukushima, could it be that the balance is tipping away from nuclear – at least in the US?
The only good answer to Fukushima is to focus on the next steps to have plants delivering energy whithout achieving criticality. However, there are few if any progress made by the community in creating subcritical reactors such as Accelerator Driven System (e.g. Energy Amplifier). What are the progresses and the investment made in subcritical reactor?