The Department of Energy’s National Nuclear Security Administration (NNSA) completed the last production unit of the W88 Alteration 370, a program to modernize the W88 nuclear warhead over several years, NNSA announced Tuesday. The W88 nuclear warhead entered the stockpile in late 1988 and is deployed in the Navy’s Ohio-class Trident II D5 Submarine-Launched Ballistic Missile system. The W88 Alt 370 includes numerous updates to address aging concerns and enhance nuclear security, NNSA said in the release. The Navy coordinated…