ST. PETERSBURG, RUSSIA ? Molten metal splashed from a smelter at a Russian nuclear power plant, killing one worker and severely burning two others, but authorities said Friday that no reactors were affected and no radiation escaped.

While relatively minor, the accident Thursday occurred on the same day prosecutors announced a “catastrophic radioactivity situation” involving improperly stored materials at a chemical factory in the southern Russian region of Chechnya.

The incidents were the latest to draw questions about how Russia stores, handles and disposes of nuclear materials and waste in the wake of the 1986 explosion of a reactor at Chernobyl that spewed out radioactivity for days in the world’s worst civilian atomic accident.

“The level of nuclear safety, although it has been significantly increased after the Chernobyl disaster, is still not sufficient,” said Vladimir Slivyak at Ecodefense, a Russian environmental group. “They used to think that there is no need for extra safety measures and they still think that now.”

The smelter accident happened at the Leningrad electricity generating station in the closed nuclear town of Sosnovy Bor, 50 miles west of St. Petersburg.

Russia’s nuclear agency, Rosenergoatom, initially reported an explosion. It later changed course and described the incident as a “splash.”

It said radiation levels remained normal. The Norwegian environmental group Bellona, a longtime critic of Russia’s nuclear programs, and officials in nearby Finland also said they had not detected any spread of radiation.

A 33-year-old worker died of injuries Friday, and two others were injured, Yuri Lameko, chief doctor of the Sosnovy Bor hospital, told The Associated Press. The Emergency Situations Ministry said two of those involved suffered burns over 90 percent of their bodies.

Rosenergoatom said the smelter – run by a scrap metal reprocessing company called Ekomet-S – is on the grounds of the plant’s second unit, where a reactor was shut down for repairs in July. The plant has four reactors in all, including one of the same type that blew up in Chernobyl during the Soviet era.

Plant spokesman Sergei Averyanov blamed the accident on violations of technical and production rules.