Hot functional testing (HFT) on Unit 4, which exposed the reactor to extreme heat, showed that all systems performed in line with quality and safety standards.
HFT takes place over a series of weeks and consists of nearly 200 individual and integrated tests performed on major systems to check their performance under normal operational conditions, without the presence of nuclear fuel in the reactor.
Enec said the successful completion of the tests demonstrates the integrity and robustness of the building structure and its ability to perform safely under normal and extraordinary circumstances.
“We have incorporated the lessons learnt during the development of each unit, increasing delivery efficiency while maintaining world-class levels of quality and safety,” said Enec chief executive Mohamed Al Hammadi.
“These tests are key steps forward towards demonstrating Unit 4’s readiness to operate and bring us a step closer to having four units online to provide abundant, clean and reliable electricity, advancing the UAE’s clean energy transition and boosting energy security for the next 60 years.”
The UAE became the Arab world's first country to run a nuclear programme in April last year, when commercial operations began on Unit 1 at Barakah.
Marking the milestone earlier this year, Enec said the energy produced by Unit 1 during its first 12 months had prevented the release of more than five million tonnes of carbon emissions.
This is the quantity of emissions that would have been released if fossil fuels had instead been used to generate the power.
Unit 2 of the plant started commercial operations in March, with the third due to come online in the coming months following the recent completion of fuel load. The UAE issued an operating licence for the third unit in June.
Enec oversees the plant, while Nawah Energy Company is the operator.
By 2025, the Barakah Plant is set to produce 85 per cent of Abu Dhabi’s clean electricity and will be the biggest contributor to reducing the UAE power sector’s carbon emissions.