Nuclear looks to
be on the way out- can it do something new?
Clean energy
technology global investment, mostly focussed on renewables, has
been running at around $350 bn p.a. for the last few years. For
nuclear it fell to $17 bn last year.
In 2018,
global renewable generation capacity saw the largest annual increase ever, with
new solar outstripping additions in coal, natural gas and nuclear. The bottom line is that, quite apart from all
its other problems, as renewable costs have fallen, nuclear has become less and
less economically attractive.
So you can see why the nuclear
industry is keen to look for new openings. It’s having trouble competing in the
electricity market, but could it make some headway in the heat and transport
markets- or as a way to balance the variable electrical output of renewables?
There’s been some debate over
options like this: http://www.world-nuclear-news.org/Articles/Nuclear-is-the-key-to-hybrid-energy-systems So we though we
would review the possibilities
Reuse them? The industry is stuck at present
with large mostly old very inflexible nuclear plants, usually run 24/7 to
recoup their large construction costs. They may not be able to compete in the
power market with renewables or even new flexible gas plans, but their generation
costs are relatively low compared with old fossil plants, with their much higher
fuel costs. So could the nuclear plants be partly repurposed to try to compete
in other markets?
In theory, some of the surplus
power output from the existing plants, produced at night when demand is low,
could be used then to make hydrogen gas for heating or vehicle fuel. Indeed,
some old uneconomic nuclear plants could be switched over to that full time, as
a last stage in their careers. But that would only make sense if there was a market
for the gas and if it was lucrative enough to justify spending money on
building Power to Gas (P2G) conversion units for use just perhaps for their few
remaining years. That’s unlikely. Moreover, while old nuclear plants may run at
marginal costs (most of their construction cost having long since been paid off,
which is why they are kept running as long as possible), they may need
refurbishment to try to keep them safe, and that can cost a lot. So for old
plants there will be diminishing returns.
New plants Much better perhaps to look to new plants. They can be designed
specifically for new purposes, including for heat supply, if they can be
located near heat loads. That is where
small modular reactors are meant to come into their own. In theory, if they can
be massed- produced, they will be cheaper. And if they could be installed in or
near cities, perhaps run in Combined Heat and Power mode, that could make them even
more economically viable. Trouble is there aren’t any plant like this yet! And
would they be welcome near cities?
It may be more sensible to look to
hydrogen production, since that could be done anywhere. For example, in big
nuclear complexes well away from people, with the hydrogen being sent by pipe
or transported by tanker to users. Some see nuclear fusion going that way, if
it ever becomes viable on a large scale. But of course renewables can also be
used to make hydrogen and there will be large power surpluses available from
variable wind & solar for this at times, available to make hydrogen
wherever it is needed. In addition,
there is the option of large solar projects in deserts, producing hydrogen and
synfuels, either indirectly from electricity or directly by high temperature
dissociation of water. High temperature nuclear fission or fusion plants might
be able to do that too, in large remote complexes, but there are no special
advantages from using nuclear heat, whereas solar heat is free, and abundant in
desert areas.
Balancing options Maybe since renewables seem
likely to dominate, rather than competing with them, or finding new markets, nuclear
could find a role in supporting renewables? It is sometimes claimed that we
need nuclear to balance variable renewables. However, nuclear plant can’t vary their output rapidly and regularly. It
takes time to safely disperse the radioactive Xenon gas that is produced when
nuclear reactions are halted, especially once the reactor fuel has been in use
for some time. If not dealt with Xenon can interfere with safe plant operation.
Slow ramps downs are possible and that is done to meet low demand at night or
seasonally, for example in France, and power output can also be dumped, or the
steam to the turbines diverted for while to cut output, but that undermines the
economics of the plants: they are usually run 24/7 at full power to recoup
their high capital costs. No UK nuclear plants have been licensed to load
follow and that includes the new Hinkley plant: http://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-load-following-e.pdf
However, it is sometimes said that
the proposed new Small Modular Reactors (SMRs) could be used to balance variable
renewables. Allegedly they will be more flexible, able to vary their output
easily, either by having multiple small units, some of which can be taken off
line for a while, or by being genuinely flexible in their operation, as is
claimed may be the case for molten salt reactors. They would operate at high
temperatures, and, in theory, power output could be varied by adjusting the
molten mix. However, it seems a very long
shot technically and economically- quite apart from the safety and security
issues. There are plenty of easier balancing options that don’t involve working
with lethal corrosive radioactive materials at very high temperatures.
The current state of play For the moment, SMRs are all for the future-
none yet exist. On the ground what we are seeing are some small moves to
diversify existing large plant operations. For example, French state owned company EDF has
launched a hydrogen production and distribution subsidiary, Hynamics, to support decarbonisation of
industry and mobility using low-carbon electricity from its (large) nuclear &
(small) renewable energy fleet, which it says produce large amounts of ‘marginal cost clean electricity’: http://world-nuclear-news.org/Articles/EDF-moves-into-the-hydrogen-market
Well we will see. That
could be a marginal interim nuclear extension option. However, no one is likely
to build new large nuclear plants for this purpose, and the overall pictures
doesn’t look too good for nuclear, unless there are some breakthroughs with new
SMR technology. That’s far from certain: https://beyondnuclearinternational.org/2019/04/06/small-modular-reactors-are-dead-on-non-arrival/ It’s the same for fusion – which it is even
further off, with unknown costs, but potentially big risks: see my earlier
post in this series.
So, in the final analysis, it may be that decommissioning of old fission plants will
be the only lucrative future nuclear option!
http://www.world-nuclear-news.org/Articles/Viewpoint-The-benefits-of-sustainable-decommissionand https://theecologist.org/2019/jan/29/nuclear-decommissioning-era-approaches Although
what that’s saying really is that the cost
of the clean up will be large- and it may be more than expected: http://www.sciencedirect.com/science/article/pii/S2214629618303888?via=ihub
As for expansion, well a new reports’ title
effectively sums up a common view of the present situation: ‘High-priced and
dangerous: nuclear power is not an option for the climate-friendly energy mix’.
And that included SMRs: http://www.diw.de/documents/publikationen/73/diw_01.c.670581.de/dwr-19-30-1.pdf
But that was report from some German critics. Maybe the
last word should go to more of an an insider, Gregory Jaczko, one-time
head of the US Nuclear Regulatory Commission (NRC), initially a (cautious)
supporter. Now he says: ‘This tech is no longer a viable strategy for dealing with
climate change, nor is it a competitive source of power’.
