Work on a nuclear energy policy should begin now if the Government wants the choice of using this technology in the coming years, experts warned on Wednesday.The Republic depends on fossil fuels for 83 per cent of its energy with wind and solar power providing the main alternative sources, according to the Irish Academy of Engineering.But so-called small modular reactors (SMRs) could make nuclear energy a viable source of electricity in the future, cutting costs and greenhouse gas emissions, Eamonn O’Reilly, the academy’s energy and climate action chairman, told the Joint Oireachtas Committee on Climate, Environment and Energy.“Ireland should begin, today, to plan for the introduction of SMRs based on the assumption that the technology will prove itself and that it will be in Ireland’s best interests to have a fleet of SMRs in the future,” he urged.O’Reilly stressed that accepting the need to do this would not in itself count as a decision to proceed with using nuclear energy, but would give the State the option to do so in the 2040s, when the new technology is likely to be commercialised.Initial work on a policy should include designing the laws and regulation needed, discussions with reactor manufacturers and devising a market that would allow the technology to work alongside renewable electricity, he said.O’Reilly suggested that State companies, the ESB and Eirgrid could fund this, along with energy industry watchdog, the Commission for the Regulation of Utilities, and the Environmental Protection Agency.Engineers and scientists could do this initial work, which should take three years, when it could be “brought back to the political sphere” for an informed public debate, he explained to TDs and senators.Countries that use nuclear power depend far less heavily than the Republic on fossil fuels, cutting their carbon dioxide output, according to the academy’s submission to the committee.Those figures show that France relies on oil and gas for 47 per cent of its needs, Finland 35 per cent and Sweden 29 per cent. These countries also have hydro power, but there are only limited quantities of that available here.O’Reilly noted that big infrastructure projects take time, while policy weakness and late starts add to delays here, something for which the planning system is then blamed.“Work on building the policy foundations for SMRs needs to start now if we want to have an option of deploying them by the 2040s,” he stressed.Small reactors are unlikely to be realistic options before 2040, Dr Muhammad Bah, senior energy policy researcher, University College Dublin, pointed out.Only four of 62 different designs are operating and two of those are experimental, he told the committee.The technology faces “considerable challenges”, Bah added. These include dealing with waste, which long-term must be stored deep underground in suitable geological structures.Reactor sites need to be far from dense population centres, have access to water supplies and road and rail, he said.Bah noted that experience to date has shown that governments pick up the tab when something goes wrong with nuclear power, including stalled projects and accidents.“The cost of accidents tends to spin out of control,” he cautioned.Professor Aoife McLysaght, Government science advisor, said nuclear power was not renewable as the uranium needed had to be mined, processed and enriched.New small reactor technology is not proven to the same extent as existing nuclear power systems, she added.