Russian President Vladimir Putin listens to Defence Minister Sergei Shoigu as they attend the Navy Day parade in St. Petersburg, Russia, July 30, 2017. Picture taken July 30, 2017. Alexander Zemlianichenko | Reuters

A nuclear-powered Russian missile remains lost at sea after a failed test late last year, and Moscow is preparing to try to recover it, according to people with direct knowledge of a U.S. intelligence report. Crews will attempt to recover a missile that was test launched in November and landed in the Barents Sea, which is located north of Norway and Russia. The operation will include three vessels, one of which is equipped to handle radioactive material from the weapon's nuclear core. There is no timeline for the mission, according to the people with knowledge of the report. The U.S. intelligence report did not mention any potential health or environmental risks posed by possible damage to the missile's nuclear reactor. Russian President Vladimir Putin unveiled the new nuclear-powered missile in March, boasting it had unlimited range. Yet, the weapon has yet to be successfully tested over multiple attempts.

Russia tested four of the missiles between November and February, each resulting in a crash, people who spoke on the condition of anonymity previously told CNBC. The U.S. assessed that the longest test flight lasted just more than two minutes, with the missile flying 22 miles before losing control and crashing. The shortest test lasted four seconds and flew for five miles. Russia has denied the missile test failures. If the Russians are able to regain possession of the missile, U.S. intelligence analysts expect Moscow will use the procedure as a blueprint for future recovery operations. It is unclear whether the other missiles are missing at sea, too. While the report didn't address the potential effects of possible damage to the weapon's reactor, there remain concerns that radioactive material could leak. "It goes without saying that if you fire a missile with a nuclear engine or energy source, that nuclear material will end up wherever that missile ends up," said Hans Kristensen, director of the Nuclear Information Project at the Federation of American Scientists. Read more: Russia's new hypersonic missile, which can be launched from warplanes, will likely be ready for combat by 2020 "If this missile was lost at sea and recovered in full, then you might hypothetically be able to do it without pollution, I would have my doubts about that because it's a very forceful impact when the missile crashes. I would suspect you would have leaks from it," Kristensen added. The weapon, which has been in development since the early 2000s, is believed to use a gasoline-powered engine for takeoff before switching to a nuclear-powered one for flight, sources have said.