The call comes as Japan struggles with its tsunami-crippled Fukushima nuclear plant.
Located in Becancour, near Trois-Rivieres, the Gentilly-2 reactor produces about three per cent of Quebecs electricity.
On April 13 and 14, the Canadian Nuclear Safety Commission is to hold public hearings about a $2-billion plan to refurbish Gentilly-2, which opened in 1983.
Mouvement Sortons le Quebec du Nucleaire which includes scientists, artists and groups such as Greenpeace, the David Suzuki Foundation and Nature Quebec is to hold a news conference about its demand.
The coalition says it opposes the plant because of the potential risk to human health.