In the movie "Pu-239", what is the Pu?

The British 2006 movie "Pu-239" is a satirical movie of neglect of nuclear power workplace hazards, attempts to cover up the malpractices, extortion and the ubiquitous organized crime.

Pu is the chemical symbol of element plutonium, which is highly radioactive and toxic.

Timofei Berezin (Paddy Considine) works in Russia at a former top-secret, badly run and aged nuclear reprocessing facility plant in Skotoprigonyevsk-16, a former closed city. At the film's outset, he is exposed to radioactive contamination while selflessly trying to prevent a critical malfunction. The facility's managers tell him that his exposure was a survivable 100 rems, while accusing him of sabotage and suspending him without pay. Loyal coworkers, however, help Timofey discover the truth that he was exposed to 1,000 rems of radiation. Suffering from acute radiation poisoning, he has only days to live.

Timofei leaves for Moscow, on a mission to secure a better future for him and his wife and young son, by selling the stolen plutonium clandestinely. He hooks up with a gangster, Shiv (Oscar Isaac), in hopes of finding a buyer for a container of a little over 100 grams of weapons-grade plutonium salt.

In the end Timofei dies and the plutonium ends at the hands of two dimwit gangsters. They open the container and see only white grainy stuff. They say: "A-ha! Pu is cocaine!" and snort it - with a fatal outcome.

Timofei's wife finds out and extorts the facility boss for ample compensations.