Complex sentence: Kostin ′ s only photograph of the nuclear power plant was sent to Novosti in Moscow, but did not received a permit to publish it until 5 May 1986, since his visit to Chernobyl was illegal and not sanctioned by the authorities.
Split into simpler sentences: Kostin ′ s only photograph of the nuclear power plant was sent to Novosti in Moscow, but he did not received a permit to publish it until 5 May 1986. His visit to Chernobyl was illegal and not sanctioned by the authorities.