The Air Force has decided it must “add more vigor” to its screening of candidates for senior nuclear command, adding closer looks at health records and Internet searches for potentially damaging personal information about candidates who also have long military careers, the Air Force’s top general said Wednesday.

Gen. Mark Welsh, the Air Force chief of staff, told reporters the change was initiated as the Air Force searched for a successor to Maj. Gen. Michael Carey, who was fired in October as commander of 20th Air Force, which is responsible for all 450 of the Air Force’s Minuteman 3 nuclear missiles. Carey was fired for behavior that officials have said is linked to alcohol abuse.

Until now the selection process had focused on a candidate’s professional background, including job skills and prior assignments. Using that approach “someone would quickly (emerge as) the obvious choice,” Welsh said.

“Just assuming an obvious choice in this business is probably dangerous,” he added. “So let’s take a little bit deeper look.”

Welsh said the hiring process for Air Force nuclear commanders will now include a more intensive checking of candidates, to include a review of potential personal health issues, both physical and mental.

The review will include a Google search, a simple task that hadn’t been done before.

“What pops up when you type somebody’s name into Google?” Welsh said. “It might be worth knowing that before you nominate somebody for a key job. Some of this is common sense.”

The removal of Carey and a Navy admiral for alleged misconduct related to gambling came amid a series of disclosures about security and leadership lapses, morale problems, training flaws, and an assertion by one midlevel nuclear officer that he had found “rot” inside his nuclear missile unit at Minot Air Force Base, N.D.

Air Force and Pentagon officials insist that despite these issues, the nation’s nuclear arsenal is being operated and maintained safely.

Carey remains under investigation for alleged misbehavior that the Air Force has declined to specify but that officials have said is linked to alcohol use. In his first public comment on the Carey matter, Welsh said Carey admitted to him that he had engaged in an “embarrassing period of behavior” while on a business trip.

Welsh said the closer scrutiny of generals in the running for jobs such as Carey’s has nothing to do with Carey’s job performance. He praised Carey’s service record but said he had stumbled in a way that could not be tolerated.

Within the nuclear Air Force there are three senior command positions. One is in charge of the Minuteman 3 missiles as head of 20th Air Force; one is responsible for the nuclear-capable B-52 and B-2 bomber fleet as head of 8th Air Force; and the third oversees both the bombers and the missiles as head of Global Strike Command.

The other segment of the U.S. nuclear force is run by the Navy with its fleet of nuclear-armed Trident submarines.

The loss of Carey and Vice Adm. Tim Giardina —who was relieved of duty and demoted to two-star rank on allegations related to gambling — is part of a wider, mostly planned, reshuffling of top nuclear commanders.

On Friday, Air Force Gen. Robert Kehler is scheduled to step down, as scheduled, as commander of Strategic Command. He will be replaced by Navy Adm. Cecil D. Haney. The new No. 2 at Strategic Command is Air Force Lt. Gen. James Kowalski, who last month completed his assignment as head of Global Strike Command. Kowalski’s slot was filled by Lt. Gen. Stephen Wilson, who previously commanded the Air Force’s nuclear bomber fleet.