An engineer at the largest nuclear power plant in the United States who illegally transported software to Iran was jailed for 15 months, justice officials said Tuesday.

Mohammed Reza Alavi, 51, was convicted of illegally accessing a computer in May before later admitting a charge of transporting stolen goods, at a federal court in Phoenix, Arizona.

Alavi, a former employee of the Palo Verde Nuclear Generating Station, admitted taking sensitive software from the plant to Iran that was used to train employees on the operation of nuclear reactors.

"We are pleased that both a jury and the Judge recognized the serious nature of these crimes," US Attorney Diane Humetewa said after Tuesday''s hearing.

"A prison sentence is entirely appropriate to punish this defendant for his stealing of sensitive materials, given the potential threat to the security of information relating to a nuclear power plant..."

Prosecutors said Alavi downloaded the software onto a personal laptop without authorization in 2006, shortly after handing in his notice at Palo Verde.