Indonesia will not used to nuclear energy to meet its target of 136.7GWe of power capacity by 2025 or 430GWe by 2050, Energy and Mineral Resources Minister Sudirman Said said on 12 December. This effectively cancels a previous $8bn plan to operate four nuclear plants with a total capacity of 6GWe by 2025. "We have arrived at the conclusion that this is not the time to build up nuclear power capacity. We still have many alternatives and we do not need to raise any controversies," he noted.

The minister spoke after the National Energy Council, a presidential advisory body, completed its latest National Energy Plan, which still needs to be signed by President Joko Widodo. The plan, last revised in 2006, lays down the ground rules and guidelines for energy development in Indonesia, as well as its commitment to reduce greenhouse gas emissions.

The 2006 plan left room for nuclear energy, but the latest guidelines say Indonesia should increase the use of renewable energy sources to 23% of its total primary energy from the current target of 5% by 2025. Energy from coal is reduced to 30% from 33%, but Indonesia will rely more on oil, which is set to account for 25% energy in the next decade, up from 20% previously. Natural gas will contribute the remaining 22%. Said added that Indonesia will continue to follow developments in the field of nuclear technology and that it would remain a last-resort option for possible use beyond 2050.

Indonesia currently only operates three research reactors: a 100kW reactor in Yogyakarta, a 250kW reactor in Bandung and a 30MW reactor in Serpong, in Banten. A previous proposal to build larger-scale plants on Central Java’s Muria peninsula and in Bangka-Belitung met with resistance from local residents who feared leaks on the scale of the Fukushima disaster in equally earthquake-prone Japan.

It is not clear where this announcement leaves the Indonesia Thorium Consortium – comprising state-owned companies – PT Industry Nuklir Indonesia (INUKI), the state-owned nuclear fuel processing company; PT PLN, a state-owned power generation company; and PT Pertamina, the state oil and gas company – which signed a memorandum of understanding MOU with US company Martingale Inc on 27 October to develop thorium molten salt reactors (MSRs). According to ThorCon’s statement, Indonesia planned to commission its first such reactor in 2021.

INUKI with its licence to import nuclear fuel was to provide the thorium and uranium as required. Pertamina was to provide its expertise in moving large scale power projects from cradle to maturity and help navigate the governmental bureaucracy. PLN was to provide its expertise regarding siting the plant and connecting with the grid and had agreed to buy the power generated.

Indonesia is the world’s leading producer of tin, and part of the material recovered from tin mining is monazite, which contains thorium. "Indonesia has an abundance of monazite which could last for the next 1000 years, securing Indonesia’s energy supply if the thorium is used as a nuclear fuel." Indonesia’s National Nuclear Energy Agency estimates that Indonesia has 70,000t of uranium reserves and 170,000t of thorium reserves. However, it is not clear whether the reserves are economically recoverable.

Imardjoko said the MSR was chosen because of its passive safety, modularity and cost compared with coal. "The MSR has a simple design, which I think is the simplest design among all the Gen IV reactors. Its fuel is liquid which makes it easy to manufacture and the simplicity of the design makes it very economical to build and to operate – at least on paper the economics could compete with coal." The 1000MW MSR will use sodium beryllium flouride salt dissolving low-enriched uranium and thorium fuel. "We are not planning to just to build one or two reactors. We are aiming for at least a 20% share of the energy mix by 2050, otherwise we are not addressing climate change correctly," Imardjoko said. "We have reviewed all the MSR designs that are currently being developed and we think that the ThorCon design has the right formula to be able to be deploy in the 4-5 year time frame," he added

The choice was a high temperature gas-cooled reactor (HTGR) with a Triso Fuel or a Molten Salt reactor. Imardjoko said the HTGR is a complex design and the Triso fuel was too complex for Indonesian firms to manufacture which means it would have to be imported. However, Russia’s AA Bochvar Research Institute of Inorganic Materials (VNIINM) is currently designing coated particle fuel for a multi-functional 10MW HTGR planned for construction in Indonesia.

In April 2015, a contract was awarded to Russian-Indonesian Consortium RENUKO for the preliminary engineering design for Indonesia’s National Atomic Energy Agency (BATAN) a 10MW HTGR, and implementation of the design work started in May. The RENUKO Consortium, includes Indonesia companies Rekayasa Engineering and Kogas Driyap Consultant as well as NUKEM Technologies GmbH (part of Russian state nuclear coporation Rosatom), which is implementing the project jointly with other Rosatom enterprises including Atomstroyexport, OKBM Afrikantov, SIA "LUCH", and the Kurchatov Institute.

The scope of work to be completed by RENUKO was expected to take eight months, including preparation of a feasibility study for the conceptual design, and a basic design package. A tender for the construction of the reactor is expected to issued in 2017.

Indonesia has also expressed an interest in floating nulcear power plants (FNPPs) and in September, Rosatom subsidiary Rusatom Overseas announced that Moscow and Jakarta had signed a MOU on the construction of FNPPs in Indonesia.