HOUSTON -- Is a nuclear power plant in our back yard safe from possible terrorist attack?

Not according to what the News2Houston Investigators uncovered

The plant is 90 miles southwest of Houston. It supplies power for Houston and several other cities, which is more than 1 million Texans.

The idea of a disaster inside a nuclear plant is terrifying, especially since Sept. 11. But the hostages shown in a video were not in any danger -- it was government security drill in Nevada.

The Nuclear Regulatory Commission uses mock-terrorism drills to check up on security at the nation's 104 nuclear power plants.

They're called "OSRES," which stands for Operational Safeguards Response Evaluations.

But just south of Houston, the South Texas Project hasn't had a drill for nine years. Is the plant still fixing problems from that (previous) drill? It depends on whom you ask.

"The South Texas Project did very well," said Rick Maier in October 2001. He's with the South Texas Project.

Plant bosses assured News2Houston that their most recent mock-terrorism drill was free of any negative marks -- not a single area even suggested for improvement.

But once the Investigators obtained the report from the NRC, that's not what they found.

In 1993, the NRC said the weapons training course for guards needed work so they don't use deadly force inappropriately.

And, other employees need real keys instead of key cards to ensure the quickest access to vital areas during an attack.

So the Investigators went back to the plant to ask about those findings, and plant leaders told News2Houston they don't see findings as negative.

"They're both because we were a little overprotective. We have since addressed those issues," Maier said.

But then, in one drill, an adversary reached one target, or a crucial piece of nuclear equipment. And in one drill, an adversary entered a "vital area," meaning a room that contains nuclear equipment.

A nuclear watchdog group said that's hardly a clean report.

"Once the adversary is inside, it may be too late to prevent him from getting to the vital safety systems, which -- if destroyed -- could bring down the plant," said Paul Leventhal, with the Nuclear Control Institute.

News2Houston's Stephen Dean then asked Maier, "Can you help me understand the answer that was given at the time, versus what the documents show me?"

"Sure. We appreciate the opportunity to clear that up because we run a safe plant. It says we have an excellent contingency response program. Are there areas of concern? Yes. We can always do better," Maier said.

Maier points out the mock intruders were not successful in actually destroying any targets.

An NRC security inspector, who just retired, agreed the plant was in no danger.

He told News2Houston that the plant did well in his inspections, but he's concerned that no one knows if the problems that were found have been corrected.

The reason why. The NRC scheduled a new drill last spring to check up on the changes it suggested, but South Texas asked for more time.

Plant leaders wrote, "We request a postponement. A drill would adversely impact our ability to make those enhancements to our security program."

"The fact that this plant was not prepared for an exercise after getting six months notice that they were going to have the exercise surely suggests to me that all is not well," Leventhal said.

The Investigators also found an August 2000 report from the NRC listing two violations.

In one, a former employee used her security badge to enter a protected area without an escort. On three occasions, "the plant granted unescorted access to an individual who would not have been granted that access if a complete review had been conducted."

What that means is that people who should have failed background checks got into the plant.

In both cases, the NRC said these were problems from the past that were not fixed properly. The plant's security chief insists they are fixed now.

"Uh, that's been completed, Stephen. Our No. 1 mission is to protect the safety and welfare of our surrounding community and our people here," Maier said.

Nuclear watchdogs say it's easy to say that when you know you won't be tested again.

All of the terrorism drills have been suspended nationwide since Sept. 11. But the South Texas Project said it really is ready for anything and it has fewer problems than other nuclear plants. The plant's security boss said an NRC security inspector visited the plant earlier this month and no citations were issued.