RICHLAND — Hanford nuclear reservation workers were told Thursday that most of them should stay home for a fourth week because of the coronavirus pandemic.

But contractors are making plans for how the eventual ramp-up of work will be done.

About 10 percent to 15 percent of the site’s 11,000 workers have continued to report to the 580-square-mile nuclear reservation near Richland to do work that is essential to protect the public, workers and the environment.

About 60 percent of Hanford workers are teleworking to support on-site activities.

The economic stimulus bill approved by Congress and signed into law by President Trump allowed the Department of Energy to revise the contracts of companies that do most of the work at Hanford to continue to pay their workers and most of their subcontractor workers with federal funds.

Hanford produced plutonium for the nation’s nuclear weapons program from World War II through the Cold War.

About $2.5 billion is spent annually to clean up radioactive and hazardous chemical waste contaminating the site.