BUCHAREST, Feb 12 (Reuters) - Romanian state-owned nuclear power producer Nuclearelectrica ROSNN.BX said on Thursday it has made a final decision to invest in a small modular reactor plant, which could become Europe's first project using the technology.

The project, in the central Romanian town of Doicesti, will have six reactors, with a total capacity of 460 MW and will use technology from U.S. company NuScale Power SMR.N. Romanian Nuclearelectrica has a 50% share in the joint venture.

The final investment decision concerns the first reactor, with the remaining five conditional upon the technology's success. The deadline for finalizing the first reactor has been pushed beyond 2030, from 2029 initially.

The company did not specify the cost of the SMR plant.

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 Union state 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 European Union funds.

Nuclearelectrica has two 706 megawatt reactors that use Canadian CANDU technology, owned by AtkinsRealis ATRL.TO, formerly known as SNC-Lavalin group, accounting for a fifth of the EU state's power production.

In 2024, it signed a 3.2 billion euro ($3.80 billion) main engineering contract to build an additional two 700 MW nuclear reactors by 2032 with a consortium of four firms including U.S. Fluor Corp FLR.N and Sargent & Lundy.

The two new reactors and the SMR project would double Romania's nuclear power capacity as it seeks to cut carbon emissions to meet EU reduction goals and bolster energy security.

($1 = 0.8423 euros)

(Reporting by Luiza Ilie; Editing by Cynthia Osterman)

((luiza.ilie@thomsonreuters.com; +4021 527 0312; https://www.reuters.com/journalists/luiza-ilie;))