Billions already spent on ‘energy pipedream’
By David Blackburn
Nuclear fusion has been a long-held ambition of the nuclear industry and governments who support nuclear power for decades. Since the end of the Second World War, governments around the world, backed by elements of their scientific communities, have always lauded fusion power as the ‘next step’ above and beyond fission that is almost within reach, yet many billions has so far been spent over the past seven decades on what has often been called by its critics an ‘energy pipedream’.
Nuclear Free Local Authorities (NFLA) has rarely commented on nuclear fusion, given such energy projects have yet to be commercially realised. All have foundered around the complex challenges in developing such technology, many of which in the third decade of the 21st century remain unsolved.
In summary, to date, none of the experimental reactors in operation have produced more energy than was put into them.
However, given the current UK Government’s declared intent to invest further money in fusion reactor development with the aspiration to develop a commercially viable design within two decades, it would be remiss of NFLA not to comment on this consultation.
As Earth lacks the intense pressure generated by the Sun’s gravity, and so cannot replicate the conditions favourable to fusion found there, there would be the requirement to super-heat the interior of the reactor to 100 million degrees centigrade, or six times the Sun’s temperature, to generate the reaction. Such a temperature and the subsequent reaction would have to be safely contained with the reactor vessel.
In addition, a fusion reactor has high operating costs as the system itself ‘gobbles up’ much of the energy that it generates to run its coolant, containment, pumping and other engineering systems. Any failure of these systems at any time would compromise the safe operation of the reactor.
The reaction generated through the employment of neutron-rich isotopes of deuterium and tritium would produce harmful by-products such as:
- Progressive radiation damage to structures impacting on their long-term integrity. The neutron radiation produced knocks atoms in the surrounding structure out of alignment creating swelling, embrittlement and fatigue, and prolonged exposure would put the very integrity of the reactor vessel in peril. CoRWM said: ‘The primary components of the fusion reactor system are likely to require disposal, including the activated front wall, blanket, divertor and vacuum vessel materials.’
- The generation of radioactive waste. Fusion will generate huge masses of highly radioactive material that must eventually be safely disposed of. Many non-structural components inside the reaction vessel (and, in liquid-metal cooled fission reactors, the lithium blanket) will become highly radioactive by neutron activation. In addition, molten lithium represents a fire and explosion hazard. While the radioactivity level per kilogram of waste would be much smaller than for fission-reactor wastes, the volume and mass of wastes would be many times larger. CoRWM also challenged the presumption in the consultation paper that fusion does not generate significant nuclear waste: ‘Nuclear fusion technology is advocated as not being compromised by the burden of generating long lived nuclear wastes. It is evident that this claim is challenged by the expected generation of some significant volumes of LLW and likely ILW arisings.’
- The ever-present threat of the release of radioactive tritium. Tritium will be dispersed on the surfaces of the reaction vessel, particle injectors, pumping ducts, and other appendages. Corrosion in the heat exchange system, or a breach in the reactor vacuum ducts could result in the release of radioactive tritium into the atmosphere or local water resources. Tritium exchanges with hydrogen to produce tritiated water, which is biologically hazardous. The release of even tiny amounts of radioactive tritium into groundwater would significantly compromise public health.
- The possible production of weapons-grade plutonium 239, adding to the threat of nuclear weapons proliferation. The open or clandestine production of plutonium 239 is possible in a fusion reactor simply by placing natural or depleted uranium oxide at any location where neutrons of any energy are flying about. Fusion reactors will also have an inventory of many kilograms of tritium, providing potential opportunities for diversion for use in nuclear weapons. Just as for fission reactors, IAEA safeguards would be needed to prevent plutonium production or tritium diversion.
In addition, as plant workers would be otherwise exposed to significant doses of radiation the plant would require heavy biological shielding even when it is not operating.
In our response specifically to Consultation Questions 5 and 7 in the consultation, the NFLA is gravely concerned that the government appears intent upon ‘watering down’ the regulatory regime applicable to fusion and demands that fusion power plants should be considered to be nuclear installations under the terms of the Nuclear Installations Act 1965, and so subject to the same licensing and regulatory regime overseen by the Office of Nuclear Regulation that applies to fission reactors.