Changes are coming to Sudbury nickel miner Vale as its Copper Cliff smelter moves from a two-furnace operation to a single-furnace operation.

"We do expect that, over the next several years there will be fewer jobs in the smelter complex with a change to a single furnace," said Vale spokesperson Angie Robson in an email to CBC News.

But the change has members of United Steelworkers Local Local 6500 concerned, including President Rick Bertrand.

"Members aren't happy about it," he said. "I mean, whoever works at the smelter is concerned."

Robson said the new plan involves minimal short-term adjustments to Sudbury mine production.

"We're going to try as best we can to minimize impacts to our people through retirement and attrition and re-assignments to other operations," she said.

"A team has been formed to study the various aspects associated with this change and, over the next year, this team is tasked with putting together revised plans for a single furnace operation."

The furnace won't be shut down until 2016. No jobs have been lost so far as a result of this pending change.

Robson said Vale's current and future mine plans in Ontario do not support a two-furnace operation.