NATIONAL HARBOR, Md. -- The Air Force will redirect $500 million over the next several years for nuclear force upgrades, according to the service's top civilian. Air Force Secretary Deborah James said Monday these funds will go toward nuclear facilities, sustainment, bomber and ICBM operations, support, launch control center refurbishment, updated nuclear defender equipment and uniforms and other force improvement initiatives. James also said Air Force officers and enlisted force handling ICBMs would receive a $300 per month stipend boost, effective…