French EDF raised the estimated construction cost of the long-delayed third reactor for the Flamanville Nuclear Power Plant in Normandy by €1.5 billion or $1.6 billion, the Paris-based company announced on Wednesday.

According to the company's statement, the price of the construction has been revised up to €12.4 billion.

In June, French nuclear watchdog, ASN, ruled that the eight faulty welds in the main steam transfer pipes that penetrate the two walls of the containment of the unit, which EDF had hoped to repair after start-up, must be repaired before the reactor is commissioned.

Later, the company said that the startup of the reactor, which is already seven years behind schedule, would be further pushed back, making its start unlikely before the end of 2022.

"The provisional schedule for implementation of the preferred penetration weld repair scenario, if the target for validation by the ASN is complied with, results in the date of fuel loading at the end 2022 and reassessment of the construction cost at €12.4 billion, representing an increase of €1.5 billion," the statement read.

The second hot functional test phase at the reactor was started on Sept. 21 and will run until the end of the year, according to the statement.

France has the world's second-largest fleet of nuclear reactors, behind the U.S., and is more dependent on nuclear energy than any other nation.

The country's state-controlled utility EDF operates all of France's 58 nuclear reactors, accounting for over 75% of the country's electricity needs.

The reactor at EDF's Flamanville-3 NPP will be the first to be built in 15 years and the first 3rd generation one to be built in the country.

Construction works started in 2007 for the 1,650-megawatt unit at the Flamanville site, where two other reactors have been operating since 1986 and 1987. Completion of the third was expected by 2012 at an estimated cost of around €3.3 billion. However, the launch date has been repeatedly pushed back by construction problems and the EDF has revised both the cost and the startup date in 2010, 2011 and again in 2012.

Later, in November 2014, EDF once again announced that completion of the construction was delayed until 2017 due to delays in deliveries from French nuclear equipment supplier, Areva S.A.

In April 2015, Areva informed the ASN that anomalies had been identified in the reactor vessel steel, "leading to lower than expected mechanical toughness values."

In September 2015, EDF published the project's new timetable and said that first fuel loading and start-up of the reactor would be in the fourth quarter of 2018, while project costs were revised up to €10.5 billion.

Finally in July 2018, when weld problems at the plant were first reported, EDF further delayed fuel loading to the fourth quarter of 2019 and increased the project's cost estimate by a further €400 million. This decision pushed the total cost of the project to €10.9 billion, three times higher than the original cost estimate of €3.3 billion.

By Firdevs Yuksel

Anadolu Agency

energy@aa.com.tr