The deaths of five Russian scientists who were killed in a nuclear explosion in August were working on developing an advanced weapon, said Russian President Vladimir Putin.
“We’re talking about the most advanced and unparalleled technical ideas and solutions, about weapons designed to ensure Russia’s sovereignty and security for decades to come,” Putin told the victims’ relatives on Friday during a ceremony in Moscow, reported the Moscow Times.
The five scientists “were conducting the most complex, responsible, and critically important work,” Putin said.
“The very fact of possessing these unique technologies is the most important reliable guarantee of peace on the planet today,” he added.
The Russian leader didn’t disclose the weapons involved in the accident but said Moscow would work to improve them further.
Since August, there has been much speculation as to what caused an explosion at a test facility in Nyonoksa in the Arkhangelsk region.
International experts have believed the blast involved the Burevestnik nuclear-powered intercontinental cruise missile, known as the SSC-X-9 Skyfall to NATO, the New York Times and the BBC reported in August.
The blast was also followed by a 40-minute-long spike in radiation in the area, the report said.
U.S. intelligence sources told CNBC that the incident occurred during an attempt to salvage a lost missile from another test.
“There was an explosion on one of the vessels involved in the recovery and that caused a reaction in the missile’s nuclear core which lead to the radiation leak,” a source told the media outlet in August.
Prof Mark Galeotti, a leading Russia analyst with the Royal United Services Institute, told the BBC at the time that nuclear propulsion is a challenging endeavor to accomplish.
“There is speed versus the weight of the system, and the risk of a missile that spews radioactive exhaust wherever it goes,” he told the BBC. “These new systems have their origin in Soviet times—they’ve been taken off the shelves and given new investment.”
Edwin Lyman, a nuclear expert at the Union of Concerned Scientists, tweeted that a reactor rod may have fallen out and had become unstable during the testing.
“If this report is accurate, the only way it could be consistent with the isotopes that were reportedly detected is through an inadvertent criticality during the recovery. That may be possible—for instance if a control rod dropped out of the core while the reactor was submerge,” he wrote at the time.
Russia had tested four of the missiles between November 2017 and February 2018. All of the tests resulted in failure, the CNBC report noted.