But their account contradicted earlier evidence from the Australian Energy Regulator, which warned it could take as long as 10 years just to create a regulatory framework for the technology.
The inquiry, in its 10th public hearing, was called in October after coalition leader Peter Dutton announced plans to establish nuclear power plants in seven Australian locations if the party won the next federal election.
But details of a switch to nuclear power generation remained unclear, including a timeline for nuclear plant development, the cost to establish facilities, and how many would be required to meet Australia's energy needs.
Nuclear consultant Ian Grant told the committee Australia could have plants established within 10 to 12 years of making a clear decision about its energy future.
The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) already had a legal framework in place the nation could update and use, Mr Grant said, shortening the time for a nuclear rollout.
"We submit it would be feasible for ARPANSA to be ready to review and initiate... a formal construction licence application in less than three years from the day of a policy announcement," he said.
"A nuclear power plant based on proven designs, in our opinion, could be operational within 10 to 12 years of a government policy decision."
The timeline, he said, was based on his experience in the United Arab Emirates, which had established its first nuclear power plant in 2020 after announcing plans in 2008.
Despite questions about differences in workplace safety standards between the two countries, Mr Grant said Australia should follow the UAE example rather than look to Europe or Britain.
"I would say the keys to rapid progress in the UAE were, first, clear government policy leadership combined with very effective program management and, most importantly, the selection of a supplier who was already experienced," he said.
"Some of the well-publicised delays that have taken place in plants in Europe have really been due to the fact that they've been started with incomplete designs, temporary constructions organisations put together with no prior experience, and rather weak project management."
Energy production from UK's Hinkley Point C nuclear reactor, for example, has been delayed from 2017 to as late as 2031, and Finland's Olkiluoto reactor began operating last year, 14 years after its intended launch date.
The latest nuclear projections contradict earlier statements at the inquiry from Australian Energy Regulator Claire Savage, who told MPs nuclear guidelines could be ready within 12 to 18 months and it could take "eight to 10 years for a regulatory framework".
Construction on a nuclear power plant, she said, could not begin until the framework had been established, potentially pushing out development to 2047 when existing coal-fired power stations would be beyond their working lives.
The nuclear energy inquiry will visit Victoria and South Australia next week.
