SIR – I have long been an advocate of Dr Burton’s novel and sensible ideas for alternative ways of storing radioactive waste. But after much thought, I have become somewhat sceptical of Dr Burton’s latest idea (Letters, October 20) for disposing of liquid radioactive waste into boreholes for the following reasons:

1. Because the residence times of the brine in the rock are believed to be in the order of tens of thousands of years, the rate at which the highly active waste (HAW) would migrate away will be extremely slow!

2. The HAW will be generating a great deal of heat. Since the conductivity of the rock is quite poor, the HAW liquid in the borehole will start to boil and eventually become solid, thus preventing the further migration of additional liquid put down the borehole.

3. The rising temperature in the borehole might conceivably become so high that the various volatile fission products would be vaporised e.g. iodine – 129, caesium – 134 and - 137, thus causing a radiation hazard in the surrounding area. I’m sorry to be such a doubting Thomas, but these things need to be said.

My own belief is that the present policy of vitrifying the waste and then encapsulating the glass in a stainless steel cylinder is perfectly adequate for millions of years and that the quality of the geology is relatively unimportant.

The big problem with any repository is getting rid of the heat for up to 100 years! This problem was well recognised by the pundits at Harwell a long time ago.

(Manager of the Sellafield Nuclear Data Group, 1971-91)

  • SIR – In response to Mr Burton’s letter of last week and his idea that High Level Liquid Waste (HLLW) can be safely disposed of by letting it “drain away” under Sellafield, Mr Burton claims the NDA has raised no technical objections.

Perhaps Mr Burton or the NDA would let us know their best guess as to where they think the HLLW might eventually surface. I would venture the Irish Sea but I might be wrong; with our complex and fractured geology it could just back up into a manhole somewhere in Northern Britain.

The carrot as Mr Burton sees it would be more money spent on local essential services. Your readers will draw their own conclusions if the ethics of such a proposal merit consideration.