New Brunswick's energy minister says four to six litres of radioactive heavy water spilled at the Point Lepreau nuclear power plant.
Craig Leonard provided the legislature with an update on Tuesday's spill in the reactor building, which resulted in an evacuation.
Mr. Leonard says the spill was cleaned up by staff and there are no health or environmental concerns.
NB Power, the province's Crown utility company, says the spill occurred as the reactor's moderator system was being filled with heavy water.
That was being done as part of the utility's plan to restart the generating station, which has been undergoing a lengthy and expensive refit.
Mr. Leonard says work has resumed at the plant.