US nuclear test raises concerns of a new arms race

The US conducted a high-explosive experiment at a nuclear test site in Nevada just hours after Russia revoked a ban on atomic-weapons testing, prompting concerns of a new arms race between the world's top nuclear powers.

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The energy department, which oversees the US stockpile of more than 5,000 nuclear weapons, said Wednesday's test in southern Nevada used chemicals and radioisotopes to "validate new predictive explosion models" that can help it to detect atomic blasts in other countries.