Creation of 'lightest uranium isotopes ever' in China could lead to clean nuclear power

PUBLISHED : Wednesday, 02 September, 2015, 10:00am
UPDATED : Friday, 04 September, 2015, 12:43pm

Chinese scientists have created the lightest uranium isotopes ever, a development that could lead to cleaner and safer nuclear power.

Uranium-238, the most abundant isotope of the radioactive element in nature, has 92 protons and 146 neutrons in its nucleus. Reduce the neutrons by three and you get U-235, the most important fissile material for nuclear reactors and weapons.

Trimming the neutrons down much further was "impossible in the past", according to Gan Zaoguo of the Centre for Nuclear Matter Science at the Institute of Modern Physics in Lanzhou.

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Gan's team was able to reduce the number of neutrons in the isotope by up to 20, obtaining for the first time U-216 and U-215.

The extra-light uranium isotopes are so volatile that their existence only lasts around one thousandth of a second, meaning they could not be directly used to fuel nuclear power plants or in the creation of atomic bombs.

By creating and studying the nature of the trimmed isotopes, scientists may be able to solve key mysteries of nuclear physics and greatly improve our ability to exploit atomic power, Gan said.

While nuclear weapons and power plants have been around for decades, their performance has been judged lacking by many scientists.

Nuclear bombs, for example, cannot be used in civilian projects such as tunnel excavations due to the potential for radioactive contamination, and the safety of commercial nuclear reactors remains a pressing public concern for similar reasons.

By stripping neutrons from a uranium atom, scientists are able to get a greater understanding of its structure, potentially leading to new developments in the use of nuclear power.

Fusion reactors – which would use a method similar to how the sun generates energy, and are currently believed to be unviable due to the massive amounts of energy required for the process – could generate enormous amounts of power without generating radioactive waste, while "clean" nuclear bombs could replace traditional dynamite and other explosives used in large engineering projects.

"In a nuclear experiment – such as the explosion of an atomic bomb – we may encounter many 'noises' that prevent us from obtaining accurate data or fully understanding the process," Gan said.

"These 'noises' can be created by new matters that we previously knew nothing about."

This can include uranium isotopes such as those created in the lab by Gan's team.

"The more of them we created and analysed, the better position we're in to propose and test new theories in nuclear physics."

The team created uranium atoms by firing a beam of argon against a board of tungsten, fusing the atoms, using the Heavy Ion Accelerator in Lanzhou, one of the largest research facilities of its type in the world.

The lightest isotopes were then detected by the Spectrometer for Heavy Atoms and Nuclear Structure, another major nuclear research facility recently built in China.

The discovery of the two isotopes was detailed in two separate papers in the European Physical Journal A and Physical Review C run by the American Physical Society.