The presenter of the BBC Horizon  programme which dealt with the safety of nuclear installations broadcast on 14 September was careful to avoid commitment but clearly implied that, based on the concept of tolerability of risk, the nuclear energy industry is as safe as any other of equal size and complexity. Available statistics of related health detriment seem to back up this contention.

Since 1965 the nuclear industry in the UK has been appropriately regulated; no nuclear installation can be operated until the Nuclear Installations Inspectorate is satisfied that safety cases prepared by a licensee are adequate. It is my understanding that retrievability following an incident (for example an earthquake) is an associated requirement of adequacy.

The presenter also raised the question of disposing of nuclear waste, suggesting perhaps that disposing of all nuclear waste to a deep Earth repository might not be the right thing to do. The presenter went on to explain that if this form of disposal (current government policy) is adopted then nuclear waste will just ’sit there’ until it decays in thousands of years’ time, thereby presenting a problem for future generations. I agree with the latter part of the presenter`s comment but disagree that the waste will just ’sit there’.

Radiation can change the environment. Radiolysis of water will produce hydrogen, oxygen and hydrogen peroxide; radiolysis of organics and the actions of bacteria will produce methane, complex ligands and other flammable gases. Corrosion of Magnox swarf will produce even more hydrogen. These factors, together with the presence of other oxidants in organic waste, will significantly increase the risk of fire or explosion in a situation where events developing after closure cannot be easily monitored. Should repositories be hermetically sealed then heat will build up to an extent that detonation could occur. Radioactive elements will become mobile and enter the geology.

In my opinion the risk of abandonment is too great - particularly since we have the technology to reduce volume, recover useful radioactive material and even accelerate radioactive decay. Chemists who discovered nuclear fission and developed the means to exploit its potential can surely deal with the legacy of radioactive waste. After all, they deal well with other non-radioactive but toxic material such as asbestos.

That a proposal for a deep Earth disposal is still on the cards surprises me since, so far as I am aware, no site for a repository has yet been found in Britain nor has any waste form suitable for disposal yet been developed.

D Bradley FRSC CChem 
Liverpool, UK 


I was puzzled by the letter from David Zuck in September’s issue, ascribing to me in my article on nitrous oxide (Chemistry World, June 2011, p44) the view that the public is prejudiced against the potential medical benefits of drugs if they have been used for recreational purposes. In fact, I stated that it was the government of the time which encouraged the writing of pamphlets satirising the activities of Humphrey Davy and others at the Pneumatic Institution in Bristol, and this discouraged experimentation on the medical benefits of nitrous oxide. 

Government legislation more often provides the disincentive to clinical investigation of the medical benefits of recreational drugs rather than public prejudice. An excellent example is provided by Baroness Wootton’s report on cannabis in 1969 in which she recommended preparations of cannabis should be available on prescription for medical treatment. The government promptly ignored this recommendation, instituted the Misuse of Drugs Act (1971) and made cannabis a category B drug. So it took until last year before the UK company GW Pharmaceuticals gained approval to market the first cannabis preparation (Sativex, a mixture of d -9-tetrahydrocannabinol and tetrahydrocannabidiol) for alleviation of the symptoms of MS. 

The current exciting clinical results being obtained with LSD (anxiety and pain in terminal illness) and ectasy (post traumatic stress disorder) will undoubtedly take many years to be translated into medical benefit due to government prejudice not public prejudice. 

John Mann FRSC 
By email 


I was most interested in the statement by Jamie Grunlan ( Chemistry World, October 2011, p10) that ’1 per cent of the GDP is lost through fire each year’. He is affiliated to Texas A&M University so presumably that figure relates to the US.

The figures which follow in this letter represent the cost of fire fighting in the US as a percentage of the GDP.1 The 2006 figures for the US according to a World Bank source are GDP $1.3 trillion and amount spent on fire fighting
$33 billion, meaning that fire fighting costs a sum equivalent to 0.25 per cent of the GDP. I am not sure how this relates to the 1 per cent ’lost through fire each year’: does it mean that the damage caused by fire costs four times as much as the fire fighting which limits such damage? If so, what is the significance of that?

If one divides the cost of fire fighting in the US by the population of the US one obtains the result: $33 billion per year/300 million persons = $100 per person per year, which means that every man, woman and child in the US pays about $100 per year towards the fire fighting costs of the nation.

J C Jones FRSC 
University of Aberdeen, UK 


In opposition to the letter Leave philosophy to the philosophers  (October 2011, published online only) the modernisation of chemistry owes a lot to the logical formats in philosophy from induction to deduction. Empiricism, which was formed by philosophy, is a fundamental part of the scientific method. Chemistry and philosophy should go hand-in-hand, having fluidity of mind for the acceptance of new ideas yet having strict guidelines based on laws and reality, as well as perpetuating questioning. Since quantum mechanics - in extension quantum chemistry - has strong ties to metaphysics, a philosophical take is logical.

J Cox  
By email