ALBUQUERQUE, N.M. (AP) — The estimate for fixing a new but inoperable $213 million security system at the nation’s nuclear bomb lab has doubled, officials with Los Alamos National Laboratory confirmed Friday.

Lab director Charles McMillan sent employees a memo this week saying it will cost an additional $41 million and take six months to fix the system, which has been under construction for seven years and was supposed to be complete this summer.