US to build new nuclear gravity bomb

 

                             

The new bomb will have a yield of about 360 kilotons 

US Air Force

The US Department of Defense (DoD) has announced that the Department of Energy's National Nuclear Security Administration (NNSA) will build a new high-yield nuclear gravity bomb called the B61-13 once given Congressional approval and funding.

The United States has the world's second largest nuclear weapon inventory with 3,708 commissioned warheads. That's a small fraction of what it was at the height of the Cold War and only a few hundred of these warheads are deployed at any time, but they still form the bedrock of the West's nuclear deterrent forces along with France and Britain.

Since the 1990s, it's been easy to see these weapons as the relic of a bygone age or a pointless menace best not thought about, but the US believes the need for deterrence combined with the increasingly unstable and dangerous nature of modern international relationships makes them very relevant.

However, the US nuclear stockpile has been neglected, with many warheads clocking in at well over four decades old. Because these devices are composed of radioactive materials combined with a cocktail of exotic materials, they have a limited shelf life before they become unreliable. Also, the nature of modern military threats has changed, requiring modernization of designs.

The October 27 announcement is aimed at providing the US military with a new nuclear gravity bomb without increasing the size of the overall inventory. As the B61-13 comes into service, it will phase out some of the Cold War B61-7 bombs as well as the currently produced B61-12s.

Partly for tactical reasons and partly as a political compromise between members of Congress, the B61-13 will have a similar explosive yield to the B61-7, which is about 360 kilotons. Modern strategy favors smaller-yield warheads, but having a few high-yield bombs in the inventory allows for countering larger, hardened targets and gives the President more options in mission planning.

According to the DoD, the B61-13 will also include design features of the B61-12, including better safety and security systems and a tail-mounted guidance package for greater accuracy. Though it will not likely be used by the heavy strategic bomber fleet, which is now armed with stand-off weapons, the B61-13 will be compatible with fighter bombers like the F-35 Lightning II.

"Today's announcement is reflective of a changing security environment and growing threats from potential adversaries," said Assistant Secretary of Defense for Space Policy John Plumb. "The United States has a responsibility to continue to assess and field the capabilities we need to credibly deter and, if necessary, respond to strategic attacks, and assure our allies.

"The B61-13 represents a reasonable step to manage the challenges of a highly dynamic security environment. While it provides us with additional flexibility, production of the B61-13 will not increase the overall number of weapons in our nuclear stockpile."

Source: US DoD/New Atlas