Federal agents responsible for driving nuclear weapons and other sensitive materials sometimes got drunk and were detained by police while on the job, according to a new watchdog report.

A report released Monday by the Energy Department's Office of Inspector General found 16 alcohol-related incidents between 2007 and 2009 involving personnel with the National Nuclear Security Administration's Office of Surface Transportation (OST). About 600 OST agents are responsible for safely transporting or shipping nuclear weapons and other materials across the country.

Two separate incidents involved extended overnight missions where OST agents parked convoy vehicles in safe harbor before checking in at nearby hotels, the report said. An agent was arrested in 2007 for public intoxication, and two agents were handcuffed and temporarily detained by police officers in 2009, according to the report.

"Alcohol incidents such as these, as infrequent as they may be, indicate a potential vulnerability in OST's critical national security mission," the report said.

In a statement, NNSA spokesman Damien LaVera said that NNSA officers have safely transported the nation's nuclear materials more than 100 million miles without a deadly accident or release of radiation. The report did not find evidence that agents were driving while intoxicated, he said.

"NNSA takes each of these cases very seriously, and is working to evaluate the inspector general's report and make additional improvements to the program," LaVera said.

The office requires its agents to undergo alcohol testing at least once every 12 months or when there is reasonable suspicion of alcohol use, according to the report. OST commanders ask agents during roll-call whether they are fit for duty. Officers are required to tell commanders if they are not, the report said.

The agency prohibits agents from consuming alcohol 10 hours before reporting to work, and agents found with an alcohol level of .02 or higher must be sent home. OST also conducts alcohol awareness briefings, the report said.

The inspector general's office investigated the issue after receiving allegations of alcohol-related incidents involving agents and agent candidates at the OST training facility in Fort Chaffee, Ark.