The Dept. of Energy's (DoE) Hanford Site in Washington State stores 56 million gallons of untreated radioactive and hazardous wastes resulting from decades of nuclear weapons production. DoE is constructing facilities at the site to treat these wastes before permanent disposal. As part of meeting health, safety, and other standards, work at the site has sometimes been suspended to address safety or construction quality issues. This report discusses: (1) work stoppages from Jan. 2000 through Dec. 2008 and what is known about them; (2) the types of costs associated with work stoppages and who paid for them; and (3) whether more effective regulation or oversight could have prevented the work stoppages. Charts and tables.