Researchers just produced the lightest-yet version of a uranium atom — with just 122 neutrons compared to the 146 neutrons present in more than 99% of uranium that forms naturally, called uranium-238, according to a recent study published in the journal Physical Review Letters.
New uranium isotope experiences powerful internal interaction
An isotope of an element always carries the same number of protons — uranium possessing 92, but with varying numbers of neutrons. Scientists identify isotopes labeled by the total number of neutrons and protons in their nuclei — and the new isotope has the lowest number of these particles ever discovered — 214, which is why it's called uranium-214.
The new uranium isotope was produced by Zhiyuan Zhang and his colleagues of the Chinese Academy of Sciences — using a long-term process of blasting tungsten samples with calcium and argon beams until the atoms fused. After this happened, the scientists pulled the uranium-214 atoms out of the sample via a magnetic tool called a separator. "The production of these atoms is very difficult, because not every collision can produce what we want," said Zhang, in a report from New Scientist. "About 10^18 beam particles were delivered to collide with the target, but only two nuclei of uranium-214 were produced successfully and separated."
The researchers observed the nuclei decay and found that uranium-214's half-life — which is the timespan until half of a given sample of particles has undergone radioactive decay — is roughly 0.52 milliseconds. They then executed similar experiments on two previously-discovered isotopes — uranium-216 and uranium-218 — and discovered that their half-lives were roughly 2.25 milliseconds and 0.65 milliseconds, respectively.
The team of scientists also found that uranium-214 and uranium-216 isotopes experience alpha decay, when an atom loses two neutrons and protons — which means interactions between neutrons and protons in these atoms are more potent than those in others. "Our finding might be the first experimental evidence that the strong proton-neutron interaction can play an important role in alpha decay in [heavy nuclei]," said Zhang in the New Scientist report.
And its half-life is very impressive.
More efficient, sustainable nuclear power
This is significant for several reasons, but amid a global transition toward renewable energy sources, an ultra-light version of uranium might provide more efficient sources of fuel for nuclear power generators. And efficiency is key amid a possible reclassification of nuclear power as "sustainable" by the European Commission of the European Union. Of course, this is only speculation, but the rising status of nuclear power is indisputable.
The European Commission's sustainable finance taxonomy is deciding which economic activities are sustainable investments in the region based on firm environmental criteria. Popular misconceptions of nuclear power consider it highly dangerous for the environment, but the reality shows the mode of energy generation produces low levels of CO2 emissions. One subject of debate revolves around the environmental impact of radioactive waste disposal.
"The analyses did not reveal any science-based evidence that nuclear energy does more harm to human health or to the environment than other electricity production technologies," read a report from the European Commission. Nuclear waste can be stored in deep geologic formations in ways that are "appropriate and safe," continued the report, citing cases like France and Finland, where such sites are already in advanced development stages. And, if uranium-214 can offer a substantially shorter period of radioactive decay, it might open new avenues for radioactive waste disposal that minimizes harm to the environment more than ever before.