The mob leader also tried to sell thousands of pounds of narcotics and stolen US military weapons. Credit: Dept. of JusticeShareA Japanese Yakuza leader pleaded guilty in federal court on Wednesday for attempting to traffic military-grade weapons and roughly 1,100 lbs of narcotics. Those charges alone will get someone locked up for quite a long timethrow in another conviction for trying to offload thousands of pounds of uranium and weapons-grade plutonium, and its unlikely Takeshi Ebisawa will ever leave prison.Its hard to pick the most damning evidence on display in the Department of Justices court filings. Theres an undercover agents photograph of Ebisawa brandishing a stolen US Army rocket launcher. Theres also a screenshot of a WhatsApp conversation between Ebisawa and a co-conspirator showing images of lab-confirmed heroin, the co-conspirator asking, Is this the correct packages [sic] you gave to my guys? followed by Ebisawa responding, Yes. Then theres audio of the Yakuza boss discussing nuclear weapons-grade material sales with an undercover agent he believed was a general in the Iranian army.Ebisawa pleaded guilty to six counts. Credit: Dept. of Justice Ebisawa unwittingly introduced [agents] to Ebisawas international network of criminal associates, which spanned Japan, Thailand, Burma, Sri Lanka, and the United States, among other places, for the purpose of arranging large-scale narcotics and weapons transactions, the DOJs January 7 announcement explains. If completed, these sales would have helped fund and supply multiple armed militant groups in Burma, as well as distribute drugs such as methamphetamine and heroin across New York.Apart from the narcotics and stolen munitions, Ebisawa reportedly worked for years to facilitate deals involving a large quantity of nuclear materials, according to the DOJ. To prove he possessed them, the Yakuza leader offered undercover authorities multiple pictures of rocky substances next to Geiger counters indicating their radiation levels. These were accompanied by supposed paper records confirming it to be thorium and uranium. During later meetings with undercover officers, Ebisawa later offered up 220 lbs of uranium concentrate powdercommonly referred to as yellowcake for sale. He also told an agent posing as an Iranian general that he could supply him better and more powerful plutonium for the countrys nuclear weapons program.Ebisawa sent photos of supposed uranium next to Geiger counters. Credit: Dept. of Justice Ebisawa wasnt wrong about the plutonium from a technical standpoint. Modern thermonuclear weapons rely on what is called a plutonium pit. This core component contains a gas such as deuterium and tritium that is encased in chemical explosives. Once detonated, the explosives condense the plutonium surrounding the case so intensely that it triggers a fission reaction. The transition from atomic to thermonuclear designation occurs when a warheads uranium core combines to generate a fusion reaction. This crucial detail is what boosts a weapon of mass destruction on the order of a few dozen kilotons to something like Castle Bravo, the first US thermonuclear bomb test. Although initially estimated in 1959 to generate a blast equivalent to six megatons of TNT, the device yielded a 15 megaton explosionallegedly the most powerful nuclear weapon ever detonated by the US.Ebisawas access to plutonium went beyond its potential for devastation. Plutonium occurs much more rarely in nature than uranium, meaning it generally requires sophisticated and expensive laboratory and manufacturing facilities. Buying the product outright likely would have allowed bad actors to skip more than a few steps while saving them quite a lot of cash. According to court documents, a nuclear forensic laboratory confirmed Ebisawas plutonium was weapons-grade material suitable for use in a nuclear weapon. Get the Popular Science newsletter Breakthroughs, discoveries, and DIY tips sent every weekday. By signing up you agree to our Terms of Service and Privacy Policy.Ebisawa pleaded guilty to a total of six counts: conspiracy to commit international trafficking of nuclear materials, international trafficking of nuclear materials, two counts of narcotics importation conspiracy, conspiracy to possess firearms, and money laundering.Nuclear material trafficking convictions are comparatively rare, given the industrys stringent regulations. The International Atomic Energy Agency cites only 4,243 incidents involving the illegal handling of nuclear material since 1993. Of those, however, only an estimated eight percent related to trafficking or malicious use.