High price to pay

February 9, 2012

Our current source of helium is the alpha decay of uranium and its daughter radioisotopes in the rocks of oil and gas fields ("Compound the error", Letters, 26 January, and "For He, just add electrons", 2 February). Renewing this source takes millions of years. Nuclear fusion is currently a poor method for making helium on Earth, but the alpha-emitting material (plutonium and minor actinides) produced in the current generation of fission reactors does emit the element.

My calculations suggest that one tonne of used reactor fuel would form enough helium to yield about 2ml of liquid helium a month. However, I suspect that the cost of collecting and purifying it away from the spent fuel would be exceptionally high.

One super-rare form of helium (helium-3) is typically made by man rather than nature: it is formed by the beta decay of tritium. Tritium (half-life 12 years) forms the very rare and non-radioactive helium-3, which can be separated from tritium gas.

In the past a great deal of tritium was made for nuclear bomb programmes, but I suspect arms reduction and the end of the Cold War reduced production. This reduction and increased demand for neutron detectors containing helium-3 after 9/11, when security agencies began to install more detectors at ports and border crossings, have made this rare helium isotope, vital for some research, even more expensive.

Mark R. StJ. Foreman, Chalmers University of Technology, Goteborg, Sweden

You've reached your article limit.

Register to continue

Registration is free and only takes a moment. Once registered you can read a total of 3 articles each month, plus:

  • Sign up for the editor's highlights
  • Receive World University Rankings news first
  • Get job alerts, shortlist jobs and save job searches
  • Participate in reader discussions and post comments
Register

Have your say

Log in or register to post comments

Featured Jobs

Most Commented

Monster behind man at desk

Despite all that’s been done to improve doctoral study, horror stories keep coming. Here three students relate PhD nightmares while two academics advise on how to ensure a successful supervision

celebrate, cheer, tef results

Emilie Murphy calls on those who challenged the teaching excellence framework methodology in the past to stop sharing their university ratings with pride

Sir Christopher Snowden, former Universities UK president, attacks ratings in wake of Southampton’s bronze award

Reflection of man in cracked mirror

To defend the values of reason from political attack we need to be more discriminating about the claims made in its name, says John Hendry

But the highest value UK spin-off companies mainly come from research-intensive universities, latest figures show