Note: This story was last updated at 12:50 p.m.

An Ohio congressman on Tuesday said federal and contractor officials continue to assert that senior leaders had no knowledge of failing systems before the July 28 security breach at the Y-12 National Security Complex, but he finds that unbelievable.

“It is not fathomable and not credible that the systems would have such repeated failures and have such vulnerabilities and no one knew,” said U.S. Rep. Mike Turner, an Ohio Republican. “The system didn’t just fail that night but had been repeatedly failing.”

Many of the alleged failures that allowed three anti-nuclear weapons activists to sneak into the plant on July 28, including cameras that didn’t work and guards who didn’t respond appropriately, have been documented in an Aug. 10 “show cause” letter from the National Nuclear Security Administration to B&W Y-12 as well as in an August report from the U.S. Department of Energy Inspector General. The failures were scrutinized in two congressional hearings in September, when lawmakers scolded federal officials and criticized contractors.

Not knowing about the failures might be even worse than knowing about them and not doing anything, Turner said.

Turner, who toured Y-12 on Monday and had a conference call with reporters on Tuesday, chairs the Strategic Forces Subcommittee of the House Armed Services Committee. He has introduced legislation that would have the military, rather than contractors, provide security at certain National Nuclear Security Administration sites such as Y-12.

He and Rep. Loretta Sanchez, a California Democrat and ranking member of the Strategic Forces Subcommittee, expressed their concerns in a Sept. 13 letter to President Barack Obama.

“From our preliminary oversight activities of the Y-12 site security incursion of July 28, it is clear that an unprecedented security failure occurred due to contractor incompetence and failures at every level of oversight,” the letter said. “Lapses at every level in terms of process, personnel, and accountability could have allowed a disaster.”

The system that was in place was permitted to degrade and may have been insufficient, Turner said Tuesday.

In their letter to Obama, he and Sanchez said the issues may not be limited to Y-12. They said security at DOE-NNSA facilities is inadequate and the facilities could be “gravely at risk.”

Turner’s legislation, called Securing Our Nuclear Weapons and Facilities Act, would transfer responsibility for providing security at certain NNSA sites to the U.S. Department of Defense. Under the bill, the military would provide security for nuclear weapons and special nuclear material at NNSA sites like it does for nuclear weapons in military custody, the congressman’s office said.

In addition, the responsibility for securing the transportation of nuclear weapons would shift to DOD.

It’s part of a debate that dates back decades over whether to use federal or contractor forces for certain types of government work. There is also a debate over what nuclear weapons work should be done by civilians and what should be done by the military.

“The July 28 incident is evidence that the current guards aren’t up to the job,” the congressman’s office said in a statement. “Much of the fault is on the larger system that enabled the failures, but ultimately several of the individual guards failed to do their jobs.”

The statement said the military is already responsible for safeguarding nuclear weapons on bases, including at facilities in Washington and Georgia.

“The military already knows how to do this and do it well,” the statement said.

Turner said he left Monday’s tour believing that officials—including Rod Johnson, who is now the senior official in charge of security at Y-12—are highly dedicated to resolving security issues. He said security at Y-12 today is better than it has ever been.

There were different types of failures that allowed the July 28 security breach, including technological problems, the performance of security personnel, and senior management and leadership failures, Turner said. But he said the problems that existed on July 28, when the three activists spray-painted slogans and splashed human blood on the Highly Enriched Uranium Materials Facility, have been addressed.

Turner said ongoing investigations will hold people accountable. There have already been a string of staff changes and a series of investigations, among other things, and security guard company WSI Oak Ridge is losing its contract at Y-12.

But Turner said he is still skeptical about whether the nation is adequately addressing security needs at NNSA facilities.

“We have no margin for error,” he said.