1 The Three Mile Island
accident was the worst
in the history of US
nuclear power
2 The cooling towers of
Three MIle Island loomed
above the town
3 Protesters at Germany’s
Gundremmingen nuclear
power plant
4 The remains of Chernobyl2r ules, they dif fer around the world, so the word ‘safe’ means something
different in different countries.” There are some conventions – almost
all safety regulations are based on probability. A plant may, for
example, need to be eng ineered to withstand an ear thquake that
occurs once ever y 100,000 years. “But this doesn’t mean that an
accident cannot happen,” says Muellner. “Weird accidents can happen- they have a small probability. But there is still a possibility that severe
accidents, including releases, may happen in nuclear power plants.”
Another problem with this approach is that the probabilities of
severe weather events are changing because of climate change. “You
can’t say for sure that the data you recorded in the last hundred years
are going to be valid in the future,” Muellner explains. “Currently it’s
not clear how to handle this. There is the requirement, from, for
example, the Western European Nuclear Regulators Association, to
take into account your safety analysis for climate change.
But how to do that is currently still under discussion.”
So, how much is nuclear energy contributing to climate change? An
operating nuclear reactor has near-zero carbon emissions, as its only
outputs are heat and radioactive waste. Of course things change
slightly when you factor in the construction and decommissioning of
the plant, the mining, processing and transportation of its uranium
fuel, and the storage of nuclear waste, but the technology still rates well
in terms of emissions when compared to coal, oil and gas. “If you don’t
replace the existing nuclear power stations that we have globally then it
makes meeting the objective of having a low carbon power system
much much harder,” says Ben Caldecott, prog ram director of
sustainable finance at the University of Oxford’s Smith School.
There is much debate over the role of nuclear power in fighting
climate change – in fact there’s a profound split in the environmental
movement. A group of people that sometimes refer to themselves as
‘ecomodernists’ reject the environmentalist belief that nuclear power is
bad. “Nuclear fission today represents the only present-day zero-
carbon technology with the demonstrated ability to meet most, if not
all, of the energy demands of a modern economy,” reads the
Ecomodernist Manifesto, a document published by a group of
researchers and activists in April 2015. “A new generation of
PHOTOS: GETTY, SCIENCE PHOTO LIBRARY
“So, how much is nuclear energy
contributing to climate change?
An operating nuclear reactor
has near-zero carbon emissions,
as its only outputs are heat and
radioactive waste”