ThorEA - Towards an Alternative Nuclear Future.pdf

Appendix VIII:
An historical UK perspective
The UK was one of the first countries to develop civil nuclear
power, opening the first commercial-scale grid-connected power
plant in 1956. The four-unit Calder Hall power station served
two purposes: the first was to produce plutonium and other
isotopes necessary for the UK nuclear weapons programme,
whilst the second was to demonstrate the useful production
of clean electricity free from the industrial-relations difficulties
and air-pollution problems of coal-based power generation.
During the Second World War the UK had been a key
contributor to the US-led Manhattan Project to develop the
atom bomb. However, the 1946 US Atomic Energy Act forbade
US collaboration with foreign powers, so from then the British
were isolated for over ten years.
The UK made an early decision to focus on plutonium-based
weapons production and this requirement motivated the
development of graphite-moderated, natural-uraniumfuelled
reactors such as Calder Hall. By 1964 the UK needed
to plan for a second generation of nuclear power plants
following the largely successful Magnox programme; various
prototype technologies were possible such as the Steam
Generating Heavy Water Reactor at Winfrith in Dorset, or the
Windscale Advanced Gas-Cooled Reactor (AGR) prototype.
During the early 1960s France chose to migrate from gascooled
reactors to pressurised light-water reactors: the UK
stayed with graphite and gas, arguably making one of the
worst technology policy decisions in UK history. The AGR
programme suffered numerous setbacks, only some of which
were technical. It was not until the late 1990s that the UK
completed its first world-class light water reactor, based upon
a US Westinghouse SNUPPS plant design: Sizewell B in Suffolk.
Since Labour came to power in 1997 it is notable that nuclear
energy is back on the agenda, and that in the same period
the former UK research and fuel cycle company BNFL has
been systematically dismantled. From the ashes of BNFL we
have the National Nuclear Laboratory who, together with an
increasing number of UK universities, is pressing for future
reactor build.
In the context of the present report, it is interesting to note
that the HELIOS experiment, commissioned in Harwell in
1979, is a specific example of UK’s leadership in the field of
ADSR technology. In this experiment, an electron beam from
Harwell’s linear accelerator was coupled with a subcritical
assembly, conforming one of the earliest examples of
accelerator-driven subcritical devices (Lynn, 1980).
Similarly, the UK has experience of deployment of thorium
fuel: Thorium fuel elements with a 10:1 Th/Highly Enriched
Uranium ratio were irradiated in the 20 MWth Dragon heliumcooled
High Temperature Gas Reactor at Winfrith, UK, for
741 full power days between 1964 and 1973. The Th/U fuel
was used to ‘breed and feed’, so that the U-233 created from
fertile Th-232 replaced the burnt U-235 at the same rate, and
fuel could be left in the reactor for about six years.
Finally it is worth stating that of all the declared nuclear
weapon states the UK arguably has the most unblemished
record in proliferation prevention, an achievement the UK
can be proud of. The development of thorium-fuelled ADSR
would help to continue this tradition.
A report prepared by: the thorium energy amplifier association 61