(CNN) -- Federal prisons and Defense Department correctional facilities in the U.S. would need myriad operational changes if detainees held in Guantanamo Bay, Cuba, were transferred into the country, according to a Congressional investigative report released Wednesday.

However, Senate Intelligence Committee Chairwoman Dianne Feinstein, a California Democrat who ordered the report in 2008, touted it as proof the U.S. prison system could handle the detainees, many of whom are accused of terrorist acts.

"This report demonstrates that if the political will exists, we could finally close Guantanamo without imperiling our national security," Feinstein said.

According to the Government Accountability Office report, there are six Defense Department facilities within the U.S. and more than 2,000 facilities holding individuals convicted of federal crimes that could hold Gitmo detainees.

The report found that many issues would need to be considered if those detainees were transferred to one of the facilities located in the U.S.

For example, the Guantanamo Bay facility's remote location in Cuba allows the Defense Department to minimize the risk the detainees may pose to the U.S. public. But most Defense Department corrections facilities in the U.S. are located on active military bases close to the general public, according to the report.

"The physical location of the detainees could become a target for individuals and groups intent on harming the detainees, or harming the U.S. military personnel involved in detention operations, which could result in unintended harm to the general public," the report states.

The identities of Defense Department personnel working with the detainees would need to be secured to "prevent any harm" to them or their families, according to the report. This precaution already is in place at Gitmo.

If the Defense Department planned to continue conducting intelligence-gathering, such as detainee interviews, secure facilities equipped with recording devices would need to be created, an added cost.

Detainees are now protected under international law from "public curiosity," but the general public would be able to see detainees while they used outdoor recreation areas at some of these facilities.

U.S. law also prohibits the confinement of members of the armed forces in "immediate association" with foreign nationals. The Defense Department would need to relocate service member inmates if detainees were to be moved to existing facilities.

Finding space for detainees in already overcrowded U.S. prisons could also be problematic. Detainees would need to be segregated from the rest of the inmate population, causing other inmates to be triple-bunked according to the report.

The Justice Department has no plans to transfer detainees to U.S. prisons, because the law does not allow it, the report said. But the Bureau of Prisons and the U.S. Marshals Service, which operate under the Justice Department, say they could "safely and securely house and transport the detainees if requested to do so and if given the necessary resources, planning lead time, and authorities," the report states.

Three hundred seventy-three inmates who have either been charged with or convicted of a terrorism-related offense are already held in U.S. prisons.

"To say that high-risk detainees cannot be held securely in a maximum security prison is just plain wrong," Feinstein said. "The United States already holds 373 individuals convicted of terrorism in 98 facilitates across the country. As far as I know, there hasn't been a single security problem reported in any of these cases. This fact outweighs not only the high cost of maintaining Guantanamo -- which costs more than $114 million a year -- but also provides the same degree of security without the criticism of operating a military prison in an isolated location."

Feinstein requested the GAO study in 2008 during the presidential campaign when both then-President George W. Bush and challenger then-Sen. Barack Obama were talking about closing the facility.

Two days after taking office, Obama announced that Gitmo would close within a year, but Congress passed legislation preventing detainees from being transferred into the U.S.

One hundred sixty-six detainees are currently held at Guantanamo Bay in confinement conditions that range from communal living to maximum-security, segregated cells. The U.S. is currently negotiating to transfer many of the detainees to other countries. The others are either currently awaiting trial or are being held because they are considered too dangerous to transfer elsewhere, but there is not sufficient evidence to put them on trial.

The GAO did not look into whether specific facilities would be suitable to hold Guantanamo Bay detainees, only what factors would need to be considered if a transfer to U.S. soil were made.

™ & © 2012 Cable News Network, Inc., a Time Warner Company. All rights reserved.