A severe and growing global shortage of helium-3 is threatening scientific research and nuclear security
Rebecca Renner/Pennsylvania, US
A severe and growing global shortage of helium-3 is threatening scientific research and nuclear security, members of the US Congress heard on 22 April.
Helium-3 fulfils a critical role in cryogenics, neutron scattering facilities, medical imaging research, and radiation detection devices as well as a host of other applications. For decades the gas has been in adequate supply, but now stocks have dwindled while demand has risen dramatically.
The shortage, driven by increased demand for radioactivity detectors following the terrorist attacks of 11 September 2001, and decreasing production, was foreseeable, according to Congressman Brad Miller. As the key supplier and user of helium-3 for both security and scientific applications, the US Department of Energy (DOE) was in a key position to anticipate the impending shortage. However, the DOE failed to see it coming Miller said at last week’s hearing, held by the House Committee on Science and Technology’s subcommittee on investigations and oversight.
Helium-3 is the stable, inert byproduct of the radioactive decay of tritium, the radioactive heavy-hydrogen used in nuclear weapons. After the cold war, the US had tens of thousands of nuclear weapons and throughout the 1990s the supply of helium-3 exceeded demand. US tritium production ended in 1988, but the stockpile continued to grow. By 2000 the US had accumulated over 200,000 litres of helium-3.
Currently 80 per cent of helium-3 is used for radiation detectors, and while there are alternatives for this application, there are no substitutes that can be used in low-temperature research, William Halperin, a physicist at Northwestern University, Illinois, told Congress.
The supply situation is desperately uncertain, Halperin says. ’The DOE is planning to release about 11,700 litres in 2010 but it is not clear where it is going and it is not well established how or when you might get delivery, even if helium-3 is allocated to you.’
’Our customers are desperate,’ says Zuyu Zhao, principle scientist at Janis Research Company, a manufacturer of cryogenic research equipment. Despite submitting applications for helium-3 four months ago, he has not received any gas and has not been informed about the status of some applications. ’This problem affects everyone on a global scale,’ says Zhao.
In February 2009, a governmental interagency team composed of the DOE, the Department of Homeland Security, the Department of Defense, and other government agencies was formed to address the decreasing helium-3 supply. Halperin hopes that the recent Congressional hearing will improve communications between the governmental team and the scientific community.