BRATTLEBORO, Vt. — A paperboard plant has new owners, securing about 100 jobs that were in flux a few months ago. In October, Georgia-based Neenah Paper Inc. announced plans to close its Brattleboro plant, which employs about 100 people. The Brattleboro Development Credit Corp., a private, nonprofit organization, contacted Neenah and learned that the only alternative to the plant’s shutdown would be a successful sale, completed by Dec. 31, according to a news release. Enter Long Falls Paperboard LLC, a partnership based in Washington state that had been trying to buy a paper mill. Long Falls worked closely with the development corporation to complete the sale by the deadline, the release says, and the company purchased the business from Neenah and took over operations Dec. 31. The Brattleboro Development Credit Corp. owns the building and land, pending an assessment by Vermont’s Department of Environmental Conservation. Long Falls plans to buy the property from the corporation after the department’s certificate of completion is granted, the release says. The Wellington Road mill, built in 1961, has seen a host of acquisitions and name changes over the decades. Neenah bought out FiberMark Inc., the previous tenant, in 2015.