Hydro Quebec. (Luc Cinq-Mars/QMI Agency)

MONTREAL - The licence for Quebec's only operational nuclear power plant expired Friday, and the provincial government said it will spend hundreds of millions of dollars over the next 50 years to dismantle the reactor.

The Parti Quebecois campaigned against refurbishing the plant, claiming that the $4-billion price tag was financially unjustifiable, to the dismay of local leaders who decried the looming loss of jobs. Days after winning the Sept. 4 election, the PQ announced it would spend $1.8 billion over 50 years to shut the nuclear reactor down for good.

The PQ also announced it will set aside another $200 million in a "diversification fund" to help the surrounding communities retrain their workforces and spur alternative development opportunities.

The plant, in operation since 1983, is located on the shore of the St. Lawrence River in Becancour, Que., halfway between Montreal and Quebec City.

Hydro-Quebec, the province's hydro utility and operator of the reactor, will begin in the next few weeks the 18-month first phase of the dismantling process. Phase one includes defueling the reactor, treating heavy water and deactivating several systems, according to Hydro-Quebec. It also includes cutting the plant's workforce from 736 to 485 people.

Phase two involves leaving the plant dormant for 40 years, then removing the spent fuel and dismantling the site.

Hydro-Quebec estimates that the site will be fully restored by 2062.

The PQ has been widely criticized, particularly by leaders of the affected communities, for not consulting with citizens before making the decision to close the plant.

Environment groups, however, applauded the decision.