The nuclear industry as we know it was designed in order to produce high-quality fissionable material for weapons. Had the opportunity been taken to use thorium instead, a much more sustainable resource would have been available. There are thorium reactors now, and extraction of thorium from seawater does provide a potential low impact resource.
I see no alternative for the UK but to stay with a nuclear energy option, due to the large population density, however other countries , including Ireland are blessed with other options.... Particularly wind. , Spain and north Africa with Solar .
There is however an error implicit in a few of the recent postings. Nuclear materials are not and never were created in the earth's core. What has kept our planet warm has been the radioactive decay of that material which was deposited when the earth was formed. When Lord Kelvin made his erroneous calculation on the age of the earth, using the temperature calculation, and the known physics at the time, he was of course unaware of the existence of energy release by decay.