Story highlights Seventeen officers will have to undergo up to 90 days of retraining

Their unit performed poorly on an inspection, an Air Force spokesman says

The 91st Operations Group has "fallen," its deputy commander says

In an unprecedented action, an Air Force commander has stripped 17 of his officers of their authority to control and launch nuclear missiles.

The 17 are being sent to undergo 60 to 90 days of intensive refresher training on how to do their jobs. The action comes after their unit performed poorly on an inspection and one officer was investigated for potential compromise of nuclear launch codes, according to Lt. Col. John Dorrian, an Air Force spokesman.

The story was first reported by The Associated Press.

The action was taken by the deputy commander of the 91st Operations Group, Lt. Col. Jay Folds, whose officers run launch control centers for the Minuteman III nuclear missiles from Minot Air Force Base in North Dakota.

Folds announced the action in an emotionally charged April e-mail to his unit, saying in part, "Did you know that we, as an operations group, have fallen -- and its it time to stand ourselves back up?"

In that e-mail, Folds said, "We're discovering such rot in the crew force," while they are on alert status -- standing watch over the nuclear force -- that the unit is accepting of violations of weapons safety rules, and code compromises.

In words not often used by military officers, Folds told his troops to "crush any rules violators" and said, "We are, in fact, in a crisis right now."

CNN obtained a copy of the e-mail, which was also first obtained by the AP.

Dorrian confirmed that Folds was referring to a potential deliberate violation of Air Force rules regarding nuclear launch codes and the failure of his troops to report when they see potential violations.

The Air Force action affects only the 17 personnel deemed to need the training; others remain on duty.

The unit underwent a regular comprehensive inspection in March, according to Dorrian. The inspection consisted of an evaluation of 22 tasks. At the time, the unit was announced as having passed with a "satisfactory" rating, which is third on a scale of five.

But on one of the 22 tasks involving launch operations, it was rated "marginal" which is one step above "unsatisfactory." Dorrian called it the equivalent of a "D" grade.

Then the incident of potential compromise of launch codes occurred. Dorrian said the investigation found no compromise, but did find the codes were "potentially handled improperly," by one officer, who is now facing discipline. All of this then led to Folds' e-mail and action, according to Dorrian.

Dorrian noted that while some in the Air Force might view Folds' e-mail as "emotional," his actions are fully supported at the highest levels of the Air Force. In other portions of his e-mail Folds told his unit:

-- "Turn off the TVs."

-- "Clean your patches, uniforms and get your hair cut."

-- "Bring to my attention immediately any officer who bad mouths a senior officer."

While some nuclear officers are sent for retraining every year, this is the most extensive action taken to date, Dorrian confirmed. It comes after a 2008 Pentagon report was sharply critical of the Air Force for not focusing on the post-Cold War nuclear mission, and for a bomber that, in a flight over multiple states, carried nuclear-tipped missiles without the Air Force realizing it.