My understanding of what was going did not begin until I was ten when my
father and Ernest Walton were awarded the 1951 Nobel Prize for Physics
for their 1932 experiment. But my recollections of the development of
Nuclear Power span the years from its inception in 1946, during my
family’s time at Montreal and Deep River in Canada, through being taken
on my father’s shoulders to see the pit for BEPO at Harwell and going to
Geneva for the Atoms for Peace Conferences in 1955 and 1958 (I went to
see the fusion exhibits and sat at the back of the closing session at
the latter) to going up the Chimney of Windscale Pile No.1, at the
start of its demolition, during a tour of the Sellafield site.
During this time I was fortunate enough to meet many of the scientists involved, e.g. Neils Bohr, Peter Kapitza, Mark Oliphant, Bill Penny, W.B.Lewis together with the Harwell Division Heads, at my parents’ home; plus many more of the staff of Harwell at my parents’ ‘get to know you’ sherry parties. I also remember the visit of Khrushchev and Bulganin to Harwell following the 1958 Atoms for Peace Conference, creeping close to their backs when they had lunch in a marquee; and my father often saying he was ‘Off to Risley’.
The first thoughts that energy might be contained in atoms came in the
era of J.J.Thomson and Ernest Rutherford when they disintegrated atoms
using Alpha Particles from Radium and, together with Neils Bohr,
postulated that atoms consisted of a Nucleus surrounded by orbiting
Electrons. Then came Albert Einstein’s E=mc2 which was proved by my
father and Ernest Walton in 1932 by bombarding Lithium with Protons and
calculating the loss of mass versus the energy of the of the resulting
Alpha Particles. However, Rutherford did not believe that the released
energy could ever be harnessed.
used to bombard lithium with protons.
Others disagreed and, following Enrico Fermi’s claim that he had broken atoms into two or more smaller parts using Neutrons, during experiments in Rome in 1934, Lise Meitner, Otto Hahn and Fritz Strassmann in Germany took forward this work. They began bombarding Uranium with Neutrons: The story is then best told by the Article ‘The Discovery of Fission’ in the American Institute of Physics History Memories: https://history.aip.org/exhibits/mod/fission/fission1/01.html
In the meantime, Leo Szilard had postulated that a chain reaction might be possible, and, after the announcement of the discovery of Nuclear Fission in 1938, Enrico Fermi demonstrated such in Chicago, making people begin to think of the possibilities arising.
Then in 1940 Frisch and Peierls issued a memorandum on the Critical Mass of Uranium 235 needed to get a chain reaction. This started alarm bells in the Anglo/American Military circles and the ‘Manhattan Project’ was spawned, backed up by an Anglo/Canadian Atomic Project.
To smooth relations with the Americans, my father was sent to lead this, first in Montreal and then at Chalk River. Much was done: a small Graphite Pile ‘Zeep’ was built; a Heavy Water Reactor NRX designed; and work on the chemical separation of fission products. When my father returned to the UK in 1946 to lead A.E.R.E. Harwell, this work carried on under W.B.Lewis, a Canadian, and led to the Canadian ‘Candu’ Power Station design.
At Harwell, urgent research was started to find: the best materials for the reactors being built at Windscale to produce Plutonium; the best methods to separate U235 from U238 at Capenhurst; and the materials needed at Risley to create fuel elements for the reactors.
With the creation of the ‘Air Cooled, Graphite Moderated’ reactors, British Experimental Pile O (BEPO) at Harwell and the two at Windscale, it was realised that a large amount of heat energy was being wasted. So, when additional reactors were called for at Windscale, it was decided to harness this heat energy to generate electricity and the twin reactor Calder Hall Power Station, a world first, was opened by Queen Elizabeth in 1956.
Two more reactors were built at the adjacent Chapel Cross and these led to the 11 Twin Reactor Magnox Gas Cooled and the 7 Twin Reactor Advanced Gas Cooled (AGR) Power Stations being built around the UK. The last of the latter have been ‘life extended’ to 2030 when Hinkley Point ‘C’ is expected to be commissioned.
Sadly, series production was not used for the AGRs, with difficulties with the designs and cost over-runs making it too expensive to build more. So, a UK version of a Westinghouse Pressurised Water Reaction (PWR) was chosen for Sizewell ‘B’. Since 1995, this has proven to be highly reliable and is estimated to be online until 2035.
Now Hinkley Point ‘C’ Power Station is being built, using a twin UK version of a European Pressurised Water Reactor (UKEPR) which is expected to come online around 2030; Preliminary works for Sizewell ‘C’ UKEPRs have started, and other power stations of this type are expected to follow on for base load electricity.
We also need to replace the Combined Cycle Gas Turbines which now produce a large part of our electricity when Wind and Solar are not available. So, a fleet of Small Modular Reactors is proposed, with a Rolls Royce Mini PWR currently topping the bill.
But Moltex Energy, based in Warrington on the old Risley site, is offering: a Small Molten Salt Reactor to continuously put heat into storage tanks to be called off when electricity is needed; and a High Temperature Molten Salt Reactor for Process Heat, aimed in part at High Temperature Electrolysis for low-cost Hydrogen Production.
However, it galls me to see that several other SMRs proposed for the UK, use technology first developed in the UK, e.g.:
The Sodium Cooled Reactors at Dounreay and a Reactor developed in Japan being sold back to us;
The Dragon High Temperature Gas Cooled reactor built at Winfrith Heath and a reactor, again developed in Japan, being proposed for use here.
Be that as it may, with the realisation that we need Nuclear Power to beat Climate Change, I take pride in that much of what was started on my father’s watch is now needed. We need both the UKEPRs for base load and the SMRs to back up Wind and Solar.
We need to grasp these firmly and quickly, for it could be said that the wasted years, due to the Fear of Nuclear, have allowed Climate Change to happen.
Christopher Cockcroft,February 2025.