In the Energy Department's National Nuclear Security Administration, (NNSA), officials of nuclear weapons programs try to keep them out of the limelight. But extending the life of the B61 is attracting all kinds of unwanted attention.

The cost of the nuclear bomb has doubled, with estimates now projecting that the weapon designed to defend Europe could cost $10 billion. On top of the weapon's ballooning price tag, the Air Force is working on a $1.2 billion tail kit program that adds a limited guidance capability to the bomb. And the arms control community is starting to buzz about the implications.

News about the B61's cost growth and two-year schedule delay is gaining traction on Capitol Hill. The concern among lawmakers could have implications for the program and the NNSA that oversees the U.S. nuclear force.

B61 bombs are the oldest in the U.S. stockpile. They entered the force in the 1970s, and can be used on fighter jets and long-range bombers. The arsenal has five different versions, both strategic and tactical, focused on protecting NATO members.

The latest life-extension program (LEP) aims to extend their life, merging four of those variants, all with different-sized explosive capabilities, into the B61-12. The B61-12 would draw on the design of the smallest nuclear explosive, or yield, weapon. The administration says using one variant will save money, and the B61-12 weapon would add an advanced security system to prevent unauthorized access to the weapons.

A wide range of players within the nuclear weapons complex are involved in the life-extension program. According to a Government Accountability Office report from 2011, Los Alamos National Laboratory in New Mexico and Sandia National Laboratory—run by a subsidiary of Lockheed Martin, in New Mexico and California—are directly involved in designing the refurbished B61. NNSA's Pantex Plant in Texas is tasked with assembling key subcomponents of the refurbished bomb. Additional work is completed at the Kansas City (Mo.) Plant. And a host of contractors, including Lockheed Martin and Boeing, are vying for the right to assemble the tail kit.

Sen. Diane Feinstein (D-Calif.), the chair of the Senate Appropriations energy and water subcommittee, received information on the cost growth from the NNSA and the Pentagon's Cost Analysis Program Evaluation (CAPE). On the heels of CAPE's $10 billion program estimate, she is vowing to increase oversight.

“We have to find a way to stop this from happening,” Feinstein said. “We've asked that we receive monthly reports, that one person be put in charge . . . . The purpose of that is to make people solve problems quickly, before they are left and they just continue to grow.”

The outsized cost of the B61 has already had an impact on other parts of the arsenal. The administration has slowed work on other programs, including the W76 warhead, used on the Navy's Trident D5 submarine-launched weapon system, according to a congressional aide.

And the cost and schedule slip-ups have some blaming the NNSA. Rep. Michael Turner (R-Ohio), the chairman of the House Armed Services strategic forces subcommittee, says the cost growth is evidence that NNSA is “incapable of performing its basic mission.”

“For the third time in two years, NATO reaffirmed recently that it wants U.S. forward-deployed tactical nuclear weapons to remain in Europe,” Turner said last week. “Yet, we are faced with the risk, of our own doing, that we may fail to honor that commitment. Why? Because the latest NNSA estimate is that this LEP, originally projected to cost $4 billion is now going to cost at least $8 billion, and, while it has already been delayed once by NNSA, from fiscal 17 to fiscal 19, there is a risk of further delay.”

The Air Force is also working on a $1.2 billion tail kit program that would add a guidance capability. A competition among top contractors for assembly of that tail kit is already underway, and the service expects to award a contract by the first quarter of fiscal 2013.

The Air Force stresses that the tail kit would not use GPS or provide “precision” level accuracy similar to a Joint Direct Attack Munition. Rather, it would “maintain the current military effectiveness given the reduction in yield.”

Merging the four versions of the B61 into one has been used to argue for removing more nuclear material from the arsenal.

But movement to lower-yield, more precise nuclear weapons is a shift that is only now coming into public view, says Hans Kristensen, director of the Nuclear Information Project for the Federation of American Scientists. In the past, movement toward more precise and even lower-yield nuclear weapons has been rejected by Capitol Hill. “Suddenly this weapon becomes more useable,” he says.