He has played a key role in growing Bechtel's Oak Ridge-based environmental business from a single project to an organization with about 1,600 people, including about 600 in Oak Ridge.

Nemec joined Bechtel in 1982 as manager of decommissioning projects. He then managed two major environmental remediation projects under the Department of Energy's Oak Ridge Operations Office from 1984 through 1988, at which time he became manager of Bechtel's Oak Ridge Office. He held a one-year special assignment at the company's San Francisco headquarters in 1990, and was again Manager of the Oak Ridge Office from 1991 to 1993.

He led Bechtel's successful bid for the Environmental Restoration Contract at the Hanford Site in Washington State. He went to Hanford in 1994 as Vice President and Manager of Operations, and was named President of the company in 1995. Under his leadership, Bechtel moved the Hanford environmental restoration program away from paper studies and into full-scale cleanup, earning four consecutive "outstanding" performance ratings from the Department of Energy.

Prior to joining Bechtel, Nemec was employed by UNC Nuclear Industries at Hanford from 1965 to 1971 and from 1974 to 1981, holding positions in reactor operations and facility decommissioning. From 1971 to 1974 he was assistant project manager for United Power Association for the decommissioning of the Elk River reactor in Minnesota.

Nemec holds a bachelor's degree in physics from the University of Montana and has done graduate studies in nuclear engineering and business administration at the University of Washington.