Workers at the Southern Minnesota Beet Sugar Cooperative - who had been locked out for three weeks - will return to work today after voting to approve a new three-year contract yesterday. The 220 workers at the Renville cooperative showed up for work three weeks ago to find the doors locked. Repeated attempts to make contact with the cooperative were ignored. It wasn't until a mediator stepped in that the two sides were able to sit down and hammer out a new contract.