By Timothy Gardner WASHINGTON (Reuters) -The U.S. is seeking bids from contractors to help establish a domestic supply of a uranium fuel enriched to higher levels for use in a next generation of reactors, a fuel currently only available in commercial levels from Russia, the Department of Energy said on Tuesday. The DOE is seeking contracts for a maximum of 10 years from enrichment service companies to produce so-called high assay low enriched, or HALEU, uranium fuel that is enriched up to 20%, compared with traditional uranium fuel used in today’s reactors of about 5%. The department has about…