Concerns persist about pace of cleanup at US nuclear lab

Officials at one of the nation’s top nuclear weapons laboratories are reiterating their promise to focus on cleaning up Cold War-era contamination left behind by decades of research and bomb-making.

But New Mexico environment officials and watchdog groups remain concerned about the pace and the likelihood that the federal government has significantly understated its environmental liability at Los Alamos National Laboratory.

The U.S. Department of Energy has been estimating that it will be 2036 before cleanup at the lab — which played a key role in the development of the...