The "Rosatom" Russian nuclear agency that the August 8 incident occurred during a missile test on a naval platform in the White Sea, killing at least five people and wounding three others.
US President Donald Trump said on Monday that the United States was "learning a lot" from the explosion he proposed during a nuclear-powered cruise missile that President Vladimir Putin overlooked last year.
He added: "The United States has" a similar technology, although more sophisticated, "and said that Russians are concerned about air quality around the facility and beyond, a situation he described as" not good! "
Dmitry Peskov, a Kremlin spokesman, said: "Our president has repeatedly said that Russian engineering in this sector far exceeds the level that other countries have been able to reach at the moment, which is somewhat unique."
Putin used his state of the nation address in 2018 to uncover what he described as an array of new invincible nuclear weapons, including a nuclear-powered cruise missile, a nuclear-powered drone and laser weapons.
Tensions between Moscow and Washington over arms control have been exacerbated by the demise of an important nuclear treaty this month. Russia says it is also concerned about the expiration of another arms control treaty.
Referring to the seriousness of the situation in the accident area, Russian news agencies referred to the authorities as advising residents of the nearby village of Nyunoxa to leave for a short period while carrying out the clarification work.
Radiation levels in the nearby city of Severodvinsk increased by up to 16 times last Thursday, while the medics treating victims of the accident were sent to Moscow for a medical examination, the Tass news agency reported.
She added: "The nurses and the doctor signed agreements not to disclose the nature of the incident."