It is necessary to enrich the fuel by increasing the percentage concentration of uranium-235.

必须提高铀235浓度的百分比，使燃料浓集。

youdao

Such a concentration of uranium means the lifetime cancer risk in the village was more than 153 times higher than in the normal population.

如此高的铀浓度意味着该村庄的人患终身癌症的风险超过普通人群的153倍。

youdao

Radon gas in the air is present worldwide, its concentration depending on the highly variable uranium content of the soil.

在世界各地，空气中都存在氡气，其浓度取决于土壤中差别极大的铀含量。

youdao

Probably the last thing plant operator Ouchi Hisashi saw before he passed out was a blue flash in the concentration of uranium he was mixing in a steel vat.

CNN: 'We're Scared for Our Baby'

What they failed to appreciate, and what the company failed to tell them, was that a fast-breeder uses fuel that has a 19% concentration of the fissile isotope of uranium, 235U. Ordinary nuclear reactors use fuel containing around 3% of the fissile isotope.

ECONOMIST: All over in a flash