Officials at the Los Alamos National Laboratory said they will re-open the nuclear research center on Wednesday after it was closed in late June due to an encroaching wildfire.

The site in the southwestern state of New Mexico, where the atomic bomb was developed during World War II, "appears to have escaped serious damage from the Las Conchas fire," read a lab statement Sunday.

The site "will re-open to employees on Wednesday, July 6" following "the largest wildfire in New Mexico history," the statement read.

"Only senior leaders and essential services will be be permitted at the Lab on Tuesday," it added.

Flames reached laboratory property on June 27, but caused no damage. However the lab closed down temporarily, in part because the nearby town of Los Alamos, where half the lab employees live, was forced to evacuate.

All hazardous and radioactive materials were accounted for and protected during the shutdown, as were key lab facilities such as its proton accelerator and supercomputing centers, officials said.

Firefighters on Sunday gave the all-clear for the town of Los Alamos, and the 10,000 residents that had been ordered to leave began streaming back home.

The fire, the largest in New Mexico history, currently measures more than 121,000 acres (49,000 hectares). As of Sunday, it was 11% contained and had destroyed dozens of homes, according to the government-run New Mexico Fire Information website.