MOSCOW—Authorities urged residents of a village in Northwestern Russia to leave their homes, days after a nearby Defense Ministry test of a nuclear-powered engine exploded, boosting radiation levels that alarmed nearby inhabitants.
Russian officials’ failure to release full details surrounding the explosion, which killed at least seven employees of Rosatom, Russia’s atomic energy monopoly, and of the Defense Ministry, have raised suspicions over the severity of the accident and whether officials are covering up details.
In a series of statements Tuesday that were as contradictory as previous ones surrounding the explosion, the local government urged several hundred residents of Nyonoksa, where the Defense Ministry testing site is located, to leave their homes on Wednesday morning. The statements didn’t provide details on why they were being asked to leave nor where they should go.
A municipal spokeswoman said the evacuation was due to an unspecified “event” at the test site nearby planned for Wednesday, according to Russian news agencies, but she gave no further details. Hours later authorities said the Wednesday event was cancelled but didn’t address whether the evacuation was still planned. The spokeswoman’s office didn’t return calls for comment.
With a lack of reliable information coming from local officials, residents of the region have taken to online community boards to ask questions and seek clarity. Meanwhile, the mayor of Severodvinsk, the largest nearby city, went on vacation, according to local reports.
“A million questions and no answers, as always,” wrote a woman who identified herself as Elena Frolova on the community page. “Why hasn’t the mayor shown up? There’s a lot I don’t understand.” Residents of Severodvinsk rushed to pharmacies after news of the blast to stock up on iodine, which protects the thyroid gland against absorbing some radiation.
Both Russian and international authorities have shown no spike in radiation apart from the initial jump last Thursday, when Russian authorities said it rose 16 times above normal.
Though answers have been inconclusive, attempts to understand the explosion last week have shone a spotlight on Russia’s new nuclear-powered armaments, including its cruise missile program, which Russia calls Burevestnik and NATO calls Skyfall. President Trump tweeted on Monday that the accident had provided Washington with valuable insights into the program, without elaborating. The cruise missile was originally unveiled by Russian President Vladimir Putin in 2018 as a weapon that could circumvent U.S. missile defenses.
Kremlin spokesman Dmitry Peskov on Tuesday declined to say whether the blast was caused by Skyfall, but he said the U.S. had similar technology to that which prompted the blast last week. He said Moscow’s versions of the weaponry were superior to Washington’s. A day earlier, Mr. Trump had tweeted the opposite.
“Our president has said repeatedly that Russian designs in this sphere for now meaningfully surpass the level which other countries have attained,” Mr. Peskov told journalists.
Both the U.S. and the Soviet Union looked into the development of atomic-powered cruise missiles in the 1950s and 1960s, but decided the idea was impractical. Skyfall was designed after the U.S. pulled out of an anti-ballistic missile treaty in 2002, Mr. Putin has said.
Skyfall’s radio-isotope generator is meant to make the cruise missile lighter and also give it the power to fly to any corner of the world. When Mr. Putin announced the missile last year, he said the missile’s unpredictable flight pattern would make it virtually impossible to stop by U.S. air defense systems.
The missile has been tested without its atomic components successfully, said a person close to the Defense Ministry. But the results of testing with the radio-isotope generator have been mixed, the person said.
The missile would be unlikely to add any meaningful extra power to Russia’s nuclear might. The system’s intent, as well as that of the undersea Poseidon cruise missile, is to evade U.S. defenses should Washington ever build a nationwide missile-defense system.
Some questions, however, remain over whether the accident was caused by a test of Skyfall.
Rosatom confirmed that the test took place during a missile test on a sea platform on the Dvinsk Bay on the White Sea. A company spokesman said Rosatom wouldn’t discuss further details of the accident.
“What I can say is we’re talking about a radio-isotope generator,” the spokesman said, referring to a fuel system known as an atomic battery, which generates energy through the decay of a radioactive isotope.
The U.S. believes the explosion was the result of a failure at a launch facility and not a missile that exploded after launch, a senior administration official said. However it remains unclear of the failure occurred at launch or through other circumstances.
The U.S. had been aware of the explosion, the official said, but wasn’t prepared to make a determination on whether it was a nuclear explosion or one that just involved radioactive elements. U.S. officials suspect the incident poses a “significant setback” for Russia’s efforts to pursue nuclear-powered weapons, the person said.
Michael Kofman, a senior research scientist at the Arlington-based Center for Naval Analyses, also doubted the explosion was the result of a missile launch. Likely possibilities, he said, were an errant test of an experimental radioisotope thermoelectric generator designed to produce more power than existing variants, or a novel miniature nuclear reactor designed to convert heat into electricity.
The person close to the Defense Ministry also said he likewise doubted that Skyfall was responsible for the blast and said instead it was likely caused by tests of a different type of engine, called “Putin’s battery” among defense industry experts. The engine is meant to be used for space launches or the Poseidon.
Write to Thomas Grove at thomas.grove@wsj.com
