The study calculates that the plant has facilitated about six tonnes of weapon-grade or 90% enriched uranium.
该研究算出，这一工厂已经生产了大约6吨军用的或90%浓度的浓缩铀。
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The study calculates that China's Lanzhou plant, operating continuously at full capacity up to 1980, would have facilitated about six tonnes of weapon-grade or 90% enriched uranium.
The probability to produce the weapon-grade plutonium clandestinely in some countries were discussed, some possible ways to detect the clandestine production activities have been given.