Environmental Engineering Reference
In-Depth Information
designed for a life of up to forty years, and many have now had their
operating lives extended for a further twenty years. In the US, for instance,
some fifty reactors have had life extensions to sixty years. But the Magnox
and AGR designs are specific to the UK, and have generally not worked
well. Some Magnoxes closed earlier because they were uneconomic, and
the AGRs are considered very unlikely to get life extensions.
Ironically, the only UK reactor that might, on the US precedent, get a
life extension is the most recent - Sizewell B on the Suffolk coast, which
started operating in 1995 and would be due to shut down forty years later,
in 2035. Sizewell B is Britain's only Pressurized Water Reactor, the model
for most of the world's reactors in the US and elsewhere that have been
given life extensions by nuclear regulators.
At the same time, the UK has committed itself to very stringent emis-
sion cuts. Not only is the UK party to the European Union commitment
to reduce emissions (from 1990 levels) by twenty percent by 2020, but by
separate national legislation the UK has bound itself to achieve an eighty
percent reduction (from 1990 levels) by 2050.
There is no (realistic) alternative
The UK has no chance, on its current trajectory, of meeting its longer-
term emission targets while giving itself some energy security, unless it
builds new reactors just to replace the older ones coming off-line. If the
UK had no nuclear power today, its current emissions would be between
five and twelve percent higher, depending on whether the replacement
power came from gas-fired power stations or dirtier coal-fired plants. If
you wanted to save even that 5 percent of extra emissions, you would have
to take a third of the UK's 32 million cars off the road.
The UK has, relative to other countries, very ambitious national emis-
sion reduction goals. British political parties are likely to want to achieve
this by being particularly tough on decarbonizing the electricity sector, so
as to minimize cuts in aviation - the UK is after all an island with only
one international rail link. To achieve an eighty percent overall emission
cut by mid-century is reckoned to require an electricity sector that would
be forty percent low-carbon (generated by nuclear and renewable means)
by as early as 2020.
Most of this increase is already supposed to come from renewable ener-
gy, whose share of electricity generation is to rise from 5.5 percent today
to 30 percent by 2020. It is hard to imagine renewable energy managing
this six-fold increase in its share of the UK's power mix over the next
