JTAs: Testbeds provide vital data to NNSA engineers, military

  • Posted: Monday, April 10, 2023, 11:16 am

JTAs: Testbeds provide vital data to NNSA engineers, military
JTAs: Testbeds provide vital data to NNSA engineers, military.

In September 1992, President George H.W. Bush ended explosive testing of the United States’ nuclear arsenal less than 2 weeks after the so‑called “Divider” detonation at the Nevada Test Site. Though few at the time expected it would be the nation’s last live‑fire nuclear test, the Clinton Administration decision 4 years later to sign the Comprehensive Nuclear Test Ban Treaty marked an undeniable turning point in the nuclear weapons era.

Clearly, the end of live testing did not end the U.S. nuclear weapons enterprise. Today’s weapons are significantly more advanced than those of the Cold War. However, without actual detonations, how is Uncle Sam to keep his nuclear spear honed for a battle he hopes never to fight?

One key answer to that question lies in three simple words: Joint Test Assembly.

JTAs are nuclear explosive look‑alikes,” Production Manager Curtis Chamberlain said.

These mock‑ups look and respond like a completed weapon, but lack a physics package and other components. What they do have, Chamberlain explained, is the ability to record and/or transmit telemetry that feeds valuable data to National Nuclear Security Administration scientists and engineers. Without the risk to human life or the environment associated with a nuclear blast, JTA flights augment virtual testing which drives the modernization and lifetime‑extension programs at Pantex and NNSA labs elsewhere.

Following assembly by teams of adeptly trained Pantex technicians, each resulting “test weapon” records “how it is doing in flight and that everything is happening according to plan — just how it would in the real world,” Chamberlain said.

After some JTA flights, the assembly may be returned to Pantex for disassembly and recovery of additional performance data.

“The data collected during JTA assembly is strictly focused on surveillance,” said J.D. Harris, a former production manager. “It helps the design agencies with annual assessments to … maintain certification on the weapon program.”

It is a complex, ongoing process that balances the need for an understanding of how devices age, the effectiveness of new modifications, and the given quantity in the nation’s inventory. While JTA testbeds may not produce a proverbial big boom, the impact of their assembly, disassembly, and analysis are just as far reaching.

“There are quality driven tests as part of the assembly process,” Harris confirmed.

One system assembled at Pantex, the B61 12, is the twelfth iteration of a munition that entered service at the height of the Cold War as an unguided air‑dropped nuclear bomb. Another system, the W88, entered the stockpile in 1988 as a submarine‑launched system. Regardless of which system is involved, JTAs are a normal part of a weapon’s life cycle.

Chamberlain and Harris explained that the NNSA lab responsible for a given weapon system — B61 12s, W88 Alt 370s, or any number of others — determines the annual number of JTA flights to conduct. Lab staff then coordinate with the expert technicians at Pantex, ensuring the necessary components are included in each assembly, depending on what functionality each flight is designed to test.

Building and dismantling a JTA requires its own qualification program. For the men and women of these programs, the payoff is knowing that their work allows NNSA officials to assure the president of a secure nation. Occasionally, Chamberlain noted, there might be an additional bonus.

“The reward is that I am sometimes able to send [my team to observe] flights,” he said. “They get to see their product in use.”

Today, thanks to the teamwork and skills of Pantexans and their NNSA colleagues, thoroughly updated and modernized B61‑12 and W88 Alt 370 programs remain vital resources in the nation’s deterrent force.

B61 Mod 12 Joint Test Assembly
B61 Mod 12 Joint Test Assembly