By Carolyn Lochhead

Two national laboratories in the Bay Area will close Oct. 21 if the partial government shutdown continues, resulting in the furloughs of more than 7,000 employees, members of Congress said Friday.

Lawrence Livermore National Laboratory in Livermore is the largest, with 6,500 workers. Roughly 1,000 more work at the Livermore campus of the Sandia National Laboratories.

Both sites test nuclear arms and maintain the nation's weapon stockpiles. They also conduct research in alternative energy.

Rep. Eric Swalwell, D-Dublin, whose district includes Lawrence Livermore and Sandia, said the labs have been operating on funds from existing contracts that will run out in a week if the partial shutdown drags on.

The two nuclear labs "were told Oct. 21 is the last day they can use what they received from their government contract service agreements," Swalwell said.

A spokesman for the Lawrence Livermore lab directed questions to the National Nuclear Security Administration in Washington, which seeks preparations for an "orderly" shutdown. Officials at the agency could not be reached.

Berkeley, Menlo Park labs

The Bay Area is also home to the Lawrence Berkeley National Laboratory, which employs 4,200 scientists, engineers and support staff, conducting scientific research across many disciplines. A spokesman there said the lab has no plans to shut down Oct. 21.

In Menlo Park, the Slac National Accelerator Laboratory employs more than 1,500 scientists and engineers conducting advanced scientific research. The lab intends to stay open beyond Oct. 21, a spokesman said.

All four Bay Area labs are owned by the government but operated by contractors, usually a consortium of universities and private companies. As a result, they've been able so far to avoid laying off employees, unlike government agencies that have furloughed 800,000 workers.

The federal government largely closed Oct. 1 when House Republicans refused to pass funding legislation unless it included provisions to dismantle or delay the Affordable Care Act. Negotiations continued Friday between the White House and House and Senate Republicans on a possible path forward.

The House has unanimously passed legislation to pay furloughed government workers. Although the Senate has not taken up the bill, the approval by House Republicans all but guarantees federal workers will eventually be paid for the two weeks and counting that they have been furloughed.

As contractors, however, workers at national laboratories would have no such guarantee. No legislation has been approved that covers contractors.

Letter to energy chief

Swalwell said the Department of Energy, which runs the contracts for the labs, has authority to pay the workers once the labs reopen without requiring a separate act of Congress.

Swalwell drafted a letter to Energy Secretary Ernest Moniz asking that the department work with the labs to provide back pay to anyone furloughed. He has signatures from Sen. Dianne Feinstein, D-Calif., Rep. Jeff Denham, R-Turlock (Stanislaus County), and several Bay Area Democrats including Reps. Zoe Lofgren of San Jose, Barbara Lee of Oakland and Anna Eshoo of Palo Alto. All have labs in their districts.

The four Bay Area labs are among seven nationwide that together employ about 30,000 workers, many of them research scientists and engineers. The others are the Los Alamos National Laboratory in New Mexico, the Oak Ridge National Laboratory in Tennessee and the Argonne National Laboratory in Illinois.

Swalwell scheduled a town hall meeting at 1:30 p.m. Sunday at the Martinelli Event Center in Livermore to address questions about the possible furloughs.