DOICESTI, Romania, March 18 (Reuters) - Romania expects to make a preliminary investment decision next year on whether to build a small modular reactor plant (SMR), which could become Europe's first project using the technology, its energy minister said on Monday.

State-owned nuclear power producer Nuclearelectrica said in 2021 it will partner with U.S. firm NuScale Power to build SMR reactors by 2029 as part of its efforts to boost low-emission power sources.

The U.S. Ambassador to Romania, Kathleen Ann Kavalec, said on Monday that the Romanian project could benefit from U.S. financial support worth $4 billion.

Romania aims to cut its carbon emissions to meet the EU's reduction goals and bolster energy security, a more urgent issue since Russia's invasion of Ukraine in February 2022.

The European Commission said last month that it aims to connect its first SMR reactors by 2030 and use them to meet its climate objectives. NuScale’s technology has already been certified last year by the U.S. nuclear power regulator, the first such approval in the United States.

"We have the chance of being the first or among the first," Romania's Energy Minister Sebastian Burduja said on Monday after touring the proposed site for the new plant in the central Romanian town of Doicesti with company and U.S. officials, including U.S. Ambassador Kavalec.

"That is because we have ... selected the technology with the most advanced degree of maturity."

NuScale aims to build plants in Romania, Poland and elsewhere in Europe, although it terminated its SMR project in the U.S. state of Utah late last year as it faced cost and subscription issues.

Burduja said the Romanian project was much more commercially viable and could be up to a third cheaper then the Utah project.

"This visionary project has the support of the highest levels of the United States government, both politically and financially," Kavalec said.

"The U.S. EXIM Bank and the U.S. International Development Finance Corporation have committed financing to ensure the success of this SMR project in Doicesti to the amount of $3 billion and $1 billion, respectively."

Nuclearelectrica's Chief Executive Cosmin Ghita said prospective investors were also interested in providing equity for the project.

"At the moment the deadline for finalizing the first module is end-2029," Ghita said. "We are looking at a series of modular connections (to the grid)."

The project will have six reactors, with a total capacity of 460 MW. A companion solar park worth 80 MW has already been installed on site.

Romania uses a mix of gas, coal, hydro, nuclear and renewables for electricity generation and has committed to phasing out lignite - or brown coal – under terms agreed in exchange for EU funds. (Reporting by Luiza Ilie; Editing by Toby Chopra, Louise Heavens and Susan Fenton)