In order to redress the imbalance left behind by the gradual closure of Britain’s coal, gas and oil power stations, the government has announced plans to boost production of nuclear energy.
However, with the expansion of our nuclear production capabilities comes the issue of vastly increased amounts of nuclear waste. Current estimates state that by the year 2030, we are likely to have some 300,000 cubic metres of waste – highly radioactive waste at that – to deal with.
As a result, teams of scientists are currently working on an innovative new form of cement that can be used to build storage for this waste and can withstand the large amounts of radiation that it would emit.
Currently, the waste left over by our current nuclear power stations is stored above ground at facilities near the plants, but plans are being worked out now to create new, dedicated, underground facilities in order to protect the environment from the radiation.
This new concrete should prove an essential advancement, given then in order for plans to be accepted, there must be proof that any nuclear waste stored in these new underground facilities remains secure, without radiation escaping, for 100,000 years at least.
The project to design this new cement is being led by Sheffield University’s Claire Corkhill.
She spoke of the difficulty in predicting how any material will behave over such a vast timescale (in this case 100,000 years), describing finding a solution to the problem as “quite mind-boggling”.
In order to solve such a problem, the team are making use of a special facility near Oxford that contains a unique particle accelerator called a synchrotron that fires particles into materials at incredibly high speeds, allowing for the examination of reactions on minute scales.
Professor Trevor Rayment, who runs the Diamond Light Source facility, said that it is an effective tool in measuring the effects on various materials in a various ways over vast timescales.
“Many of the technological problems that affect society today are ones that take place over a very slow rate…By using our machine to measure very accurately changes taking place in the materials we are studying, we can discover how those changes might affect them in hundreds or thousands of years.”
The focus on the development of the cement is on “the interaction between water and cement granules” said Corkhill.
“We are using Diamond to predict what cement will be like thousands of years in the future. No one has ever done that before.”
The cement developed “will be able to capture all of the radioactive elements that might be released from the waste over time” she said, adding that “cements that are currently in use do not do this. Our cement will therefore make nuclear waste disposal even safer.”
The cement has been developed to be particularly good at absorbing and retaining one particular material – technetium-99.
Corkhill said: “it’s a high-yield fission product; it’s only found in nuclear reactors; it’s very mobile in the environment – but what we found is that our cement will actually lock tight this technetium-99 into its structure and prevent it being transported into the environment.”
