Emergency workers recently conducted a tabletop training exercise in Boston aimed at preparing them for a potential terrorist strike involving a radiological “dirty bomb,” the U.S. National Nuclear Security Administration announced on Thursday.

The semiautonomous Energy Department office and the FBI organized the program at Children’s Hospital Boston as part of the federal agencies’ “Silent Thunder” series of drills, which focuses on responses by multiple levels of government to the detonation of conventional explosives that disperse radioactive material in a heavily trafficked area.

Among the aims of the program are preparing local, state and federal authorities to assess the potential for such an act, respond in the immediate aftermath of a dirty bomb explosion, and deal with the longer-term aftermath of the event, according to an NNSA press release.

“These exercises are critical to improving cooperation among federal, state and local officials, and we welcome the opportunity to work with organizations like Children’s Hospital Boston to ensure effective planning, communication and response coordination,” Deputy Energy Undersecretary Steven Aoki said in provided comments. “NNSA’s investments in nuclear security provide the unique technical knowledge and capabilities that help protect our country against terrorist attacks.”

Simulations in the Silent Thunder series include the attempted acquisition of radiological material by extremists who insert themselves into a scientific site. “Participating officials work cooperatively to assess and respond to critical facility alarms and then manage the created crisis as if it was actually happening,” the release says. “The goal of these exercises is to provide firsthand crisis management experience and to improve both alarm response and emergency response methods.”

The NNSA release says only that the “Longwood Thunder” event in Boston involved a mock situation focused on radioactive substances (U.S. National Nuclear Security Administration release, Oct. 27).