Waterford — The International Brotherhood of Electrical Workers is seeking to unionize operators, mechanics and maintenance workers at the Millstone Power Station.

John Fernandes, business manager with IBEW Local 457, headquartered in Berlin, said Monday that the organizing effort began this spring, prompted by worker dissatisfaction over benefit cuts and inequities in pay rates different workers receive for the same jobs. A previous effort by IBEW to organize about 10 years ago failed to win a majority during an worker election.

IBEW, which also represents workers at Connecticut Light & Power, would like to unionize about 350 of the approximately 1,100 Millstone staff members employed by plant owner Dominion, the “working men and women” rather than the administrators, managers and engineers, Fernandes said. In a case pending with the National Labor Relations Board, Dominion has argued that if a union election is held, it should involve a larger group of employees.

“We believe that if there’s going to be representation, it should be a large group, because of the interconnectedness of different departments,” said Ken Holt, Millstone spokesman.

The company has been sending information to employees urging them not to support forming a union, he said. He declined to comment on assertions by the union about worker dissatisfaction.

“We respect the rights of employees to organize, but we believe that the best way to more forward is in a non-union environment,” Holt said. “That’s the best way to ensure the success of the station and employees.”

The hearing at the NLRB lasted 34 days over two months, and is the longest hearing ever at the Connecticut office in Hartford, said John Cotter, NLRB officer in charge. The hearing was very involved because there are more than 150 job classifications at Millstone, and each one must be considered in determining who will be eligible for the union vote, Cotter said. The NLRB expects to decide by the end of the year which groups will be eligible for the vote, which could be scheduled in about a month after the decision, unless one of the sides files an appeal, Cotter said.

Fernandes said IBEW represented workers at Connecticut Yankee in Haddam Neck until that plant closed, and noted that two other nuclear power stations owned by Dominion in Virginia also have IBEW unions.

Holt said the company maintains that a nonunion workplace provides the kind of flexibility needed so that staff can work together most efficiently and effectively to continue to improve plant processes.

j.benson@theday.com