Original sentence: A freelance killer would not be able to obtain polonium legally from commercially available products in the amounts used for Litvinenko poisoning, because more than microscopic amounts of polonium can only be produced in state-controlled nuclear reactors  (see commercial products containing polonium for detail).British mass media believes that scientists of the UK's Atomic Weapons Establishment have confirmed the polonium is likely to originate from a Russian nuclear reactor, although no official announcement had ever happened at the Avangard Electromechanical Plant in the closed city of Sarov.Ninety seven percent of the world's legal polonium-210 (210Po) production occurs in Russia in RBMK reactors   About 85 grams (450,000 Ci) are produced by Russia annually.The analysis of impurities in the polonium (a kind of "finger print") allows to identify the place of production.. It is assumed by Litvinenko's wife and his close confident that that British investigators were able to identify the place and time of production of polonium used to poison Litvinenko, but their findings remain unpublished
Edited sentence: A freelance killer would not be able to obtain polonium from commercially available products in the amounts used for Litvinenko poisoning, because more than microscopic amounts of polonium can only be produced in state-controlled nuclear reactors  (see commercial products containing polonium for detail).Ninety seven percent of the world's polonium-210 (210Po) is produced in Russia in RBMK reactors   About 85 grams (450,000 Ci) are produced by Russia annually.Scientists of the UK's Atomic Weapons Establishment have confirmed the polonium is likely to originate from a Russian nuclear reactor at the Avangard Electromechanical Plant in the closed city of Sarov.The analysis of impurities in the polonium (a kind of "finger print") allows to identify the place of production.. It is assumed that British investigators were able to identify the place and time of production of polonium used to poison Litvinenko, but their findings remain unpublished