Making assumptions

Tweet The operators of one of the UK’s AGR nuclear power stations, Dungeness B, have applied for a relaxation in the safety margin for the deterioration of the graphite core.  The dependence of this particular type of reactor on the performance of a particular material over the long term is another of those “little details” which have passed most of us by, and underlines the complex engineering challenges which the designers and builders of such stations have faced.

In itself, the proposed relaxation is probably not a major concern; the level was set on a fairly arbitrary bases in the first place (with a large margin of error presumably).  No one can really be certain what the “right” limit is exactly until it’s reached – which will of course be too late.  But I’m actually less concerned about the specific proposed relaxation than I am about the reasons for the deterioration exceeding expectations, which seems to me potentially a much greater problem.

There’s already talk of the need for a further relaxation in three years’ time: and whilst repeated relaxations should concern us more than just the one, most of us don’t have the technical expertise to know whether we should really be worried or not.

But actually, the aspect of all this which concerns me most was not the relaxation itself, or even the potential need for a further one in three years’ time.  It was, rather, the statement that they want to keep the AGR’s running until at least 2023 “... until the planned next generation of nuclear power stations came on line ...”.  I do not believe for one moment that there will be a single new reactor producing electricity in the UK by 2023 or for some years after that, and I find it hard to believe that even the strongest supporters of nuclear energy can seriously be planning on the basis of such an assumption.  And here’s my real concern about the proposed relaxation at this stage: relaxing the rules a little on the basis of an invalid planning assumption, instead of looking for a viable alternative now, could end up locking us into a situation where there is “no choice” but to make further relaxations every few years.

And it might not just be the graphite cores in the end; other components of the stations will also come to the end of their design lives as well.  We could easily be facing a “need” to make further compromises with safety.

What we really need is not to relax safety standards, but a planned move away from nuclear generation.  Neither the companies looking to make a profit nor the politicians who see only jobs when they look at nuclear power stations are helping with that.