WASHINGTON (AP) — Three years after the Sept. 11 attacks, the Nuclear Regulatory Commission cannot independently verify that every nuclear power plant is taking required safeguards to protect against a terrorist threat, congressional investigators said Tuesday.

Senior NRC officials strongly challenged that assessment and said the agency, through onsite inspectors and other activities, is aggressively monitoring security compliance at the nation’s 103 reactors at 65 sites.

The Government Accountability Office told a House subcommittee that the NRC’s monitoring of reactor security has been largely “a paper review” that falls short of assuring that industry security plans are meeting the more stringent requirements now demanded.

At the same time, the GAO, which is the auditing arm of Congress, said critical “force-on-force” mock attacks to physically test security at the plants will not be completed at all facilities until late 2007.

“It will take several more years for NRC to make an independent determination that each plant has taken reasonable and appropriate steps to protect against the (terrorist) threat presented,” GAO investigator Jim Well told a House Government Reform subcommittee on national security.

NRC officials, who also testified before the panel, strongly disputed the GAO assessment and said the agency has increased inspection hours at the power plants fivefold and has physically reviewed 80 percent of the security items plant operators must address.

“We have inspectors (at the plants) all the time,” said Luis Reyes, the NRC’s executive director for operations. “We are there where the rubber meets the road when it comes to inspections.”

The GAO report also criticized the NRC for “not following up to verify that all violations of security requirements have been corrected” and for not filing official reports on all such incidents.

At least two NRC inspectors are assigned to each of the 65 commercial nuclear power plant sites in 31 states. Reyes acknowledged they have broad responsibilities and do not file written reports on all security shortcomings — only “the more significant ones.”

Those viewed as of “low level” importance are evaluated on a sample basis, he said. “It’s a matter of resources.”

Rep. Christopher Shays, R-Conn., chairman of the subcommittee, said there still “is no reasonable assurance plants are adequately protected” even though the NRC in April 2003 developed new standards as to what kinds of potential terrorist attacks plant operators must be prepared to repel.

He accused the NRC and industry of trying to “minimize the risks” of a terrorist attack that could lead to a radiation release and accepting “a cozy, indulgent regulatory process that looks and acts very much like business as usual.”

That brought an emotional response from Roy Zimmerman, head of the NRC’s security office, who said he was concerned that lawmakers were assuming the NRC is not paying attention to security.

“We’re laying awake at night. We’ve very concerned,” Zimmerman said. “We’re constantly looking and working very long hours to get out ahead of those that want to do us harm. We’re not lackadaisical.”

In separate testimony, nuclear industry representatives said utilities have spent more than $1 billion on security improvements and increased security forces by 60 percent, hiring 3,000 additional officers, since the Sept. 11, 2001 , attacks.

“Nuclear power plants are the most secure commercially owned facilities in the country,” said Marvin Fertel, senior vice president of the Nuclear Energy Institute, the industry trade group.

Among the improvements cited were expansion of security perimeters around plants, more patrols within security zones, installation of new barriers to protect against vehicle bombs, installation of high-tech surveillance equipment, increased communications and coordination with local, state and federal police authorities. The NRC also has required plants to conduct force-on-force mock drills once every three years, instead of once every eight years as required before 2001.

On the Net:

Nuclear Regulatory Commission: http://www.nrc.gov

Nuclear Energy Institute: http://www.nei.org

This article originally appeared in the Associated Press news service