Making movies is a lot like physics: Both require millions of dollars worth of equipment and hundreds of people; and, once a run is completed, if you're very lucky you get a few seconds of usable data.

My adventure in movie-making began in March 1995 with a telephone call from a representative of the Illinois Film Commission, asking if she could send a photographer to Argonne to take pictures of some laboratories that might make a good backdrop for a planned movie -- an action thriller, she said, but with a scientific theme.

Argonne has a good many large laboratory facilities which might be suitable, but they're in heavy use. Flooded with images of me being called before a Congressional committee on waste, fraud and abuse, I contemplated her request. Then I remembered a large research facility on site, called the Continuous Wave Deuterium Demonstrator, or CWDD, built with Army money to do ground-based Star Wars research but never activated. The facility was nearly built when Congress canceled Star Wars research, and with it Argonne's project.

I picked up the phone to call the manager of the project at the time of its cancellation, physicist Tom Yule, trying to remember if he had even the tiniest sense of humor.

"Tom," I said, "don't be offended by this question, but how would you feel about CWDD being used for a movie?"

His delighted hoot of laughter reassured me. "What's it about? Who's directing it?" he asked. "I don't know much about the plot yet," I said, "but the director is Andrew Davis."

"I loved `The Fugitive'!" he said. "Let's do it."

And with those three words it all began. First, the film commission photographer arrived, and Tom and I showed him around the cavernous CWDD facility, with its accelerator, its detectors and its collection of hydrogen tanks. The entire facility had been declassified and released to Argonne the year before, and proposals had been written for other research projects to be done there, but none had been funded.

The photographer professed delight with our offering, but our enthusiasm was dimmed when he reported that he was also photographing Fermilab, the University of Chicago, Northwestern, the Illinois Institute of Technology and others. All photos would be shipped to Andrew Davis, who would decided which ones he wanted to pursue.

Weeks passed. They turned into months. Then, in July, another phone call. Mike Malone, location scout for 20th Century Fox, wanted to come to Argonne to take some more pictures.

The plot of the movie, we learned, centers on a breakthrough discovery by a University of Chicago physicist, who is developing a way to separate water so that the hydrogen can be used as fuel. The technology is a combination of lasers and ultrasound, culminating in a special nozzle designed and built by technician Keanu Reeves. Once the technology is developed and demonstrated, the physicist wants to make a worldwide announcement. Evil corporate and government forces have other ideas; the physicist is killed, the laboratory destroyed, and the idealistic young technician is framed for the crime. He takes it on the lam, accompanied by a glamorous physics post-doc. (Happens all the time.) The post-doc is kidnapped by the bad guys, and Keanu traces them all to a clandestine underground laboratory in Virginia called Mount Weather. (That's the part Argonne was auditioning for.) Thrilling intrigue ensues.

So Mike comes for another visit. Tom and I wandered around CWDD again, pointing out features as Mike's camera whirred.

More weeks passed. It's now autumn. Mike calls again. He'd like to make another visit, and he'd like to bring along director Andrew Davis, production designer Maher Ahmad, and a dozen others who'd like to look over the facility. Tom was beside himself with joy at the prospect of meeting Andrew Davis. This was beginning to sound less like a whim and a long shot, and more like something that was going to get complicated.

So the retinue arrived, and we did the tour again. As they wandered around, Tom was talking about the history of the area, and how projects had come and gone over the laboratory's 50 years. The warehouse-sized buildings in this particular area of the laboratory had housed dozens of different projects, Tom said, and engineers and technicians had moved from building to building, depending on their expertise on a given project. The tunnels connecting the buildings had been heavily used over the years, Tom added.

Andrew Davis turned with a gleam in his eye. "Tunnels?" he asked. It was only later that I learned that Andrew Davis's movies are famous for their chase scenes. We descended into the tunnels, accompanied by guide Frank Brumwell, a long-time Argonne engineer said to be the only person who had walked every inch of the tunnels.

I learned many valuable things on the tunnel tour: Argonne is an even more interesting place than I had realized; tunnels with miles of steam pipes can really excite a director of chase scenes; and it's not a good idea to wear your best suit and heels to walk approximately 900 miles in concrete tunnels, even if you are meeting the director of an Oscar-nominated film.

But we were in. I could add many paragraphs here about how my boss, Charlie Osolin, and I cajoled and encouraged Argonne's management and the Department of Energy, our landlord, into going along with this, but that's a story for a management magazine. And we continued to show off the joint for movie folks. First, Davis brought out Keanu Reeves, who had signed to play the genius technician. We sneaked him in, not getting him a visitor's badge, but the grapevine worked overtime, and he hadn't been there for a hour before we had employees clustering in hallways to watch Keanu pass by. One enterprising reporter from a suburban daily called my office to ask if it was true that Keanu Reeves was at the lab, and could she come out to interview him. (Yes, and no.)

We had slightly better luck a few weeks later, when Morgan Freeman came out for his first visit, a meeting with engineers similar to his character in the movie. We smuggled him in too, for lunch at the lodge and a tour, and dodged autograph-seekers.

It was a slightly different story the day Keanu and Morgan both came, with others, for a discussion with Argonne management in the lab's administration building. For those who've never been to Argonne, that building features a lobby atrium. The lab's director's office is on the second floor, and the atrium area is surrounded by railings and balconies on the second and third floors.

We made it into Dr. Schriesheim's office without interference, and settled in for an interesting meeting. Morgan Freeman was particularly delighted when he learned that Argonne's director, Alan Schriesheim, is a chemist by training, "I've been wanting to talk to a chemist," Freeman declared. "I'm don't believe that this process in our script would really work."

Well, Dr. Schriesheim responded, it probably wouldn't. If it did, it would violate at least a couple of laws of thermodynamics. But, he added, "It's a movie. It's not important that it be real; it's important that it believable."

Satisfied that even chemists can deal with made-up science, Freeman and the rest settled in to discussing ways to make the plot believable and realistic.

About an hour later, we emerged to find employees clustered throughout the lobby, and others hanging off the railings on the upper floors. Argonne's security chief, Dave Metta, responded to our call and escorted the celebrities out of the building and off site.

We had one more big pre-production session, when about three dozen movie folks came out for lunch and a tour, including producer Richard Zanuck, who won an Oscar for "Driving Miss Daisy." It was Zanuck's birthday, and Davis and his staff had brought out a birthday cake as a surprise. So now I can say I've been to Richard Zanuck's birthday party.

At last, in late January, the construction began on the movie set at Argonne, and about 30 people built a fake multi-million-dollar laboratory in a week. The set is magnificent: A giant hydrogen tank in the center of the lab, surrounded by a control room with banks of computers and video monitors. An elaborate laser light arrangement sits on a nearby table, and dozens of smaller work stations dot the rest of the set. After the set designers came the lighting guys, and at 5 a.m. on Feb. 12, about 125 movie makers rolled into the Argonne site to begin the first week of shooting.

The most accurate thing I can tell you about making a movie is that it's repetitive. There is no such thing as accomplishing a scene in one take; there are dozens of takes, and then dozens more from a different angle, and then dozens more from another. Actors improvise, and slightly change their lines, in part trying out different approaches, in part just keeping themselves awake.

Argonne employees dropped by on occasion to watch for a while, but few lasted for long. "I never realized this could be so boring," I heard more than once. And it is. In addition, it takes an iron constitution to deal with the 12 to 14 hour days. But I learned how the cast and crew handles it: They eat all the time. Movie companies have two caterers, one to cook huge breakfasts and lunches, and another to provide snacks such as sandwiches, chips, cookies and fruit for the rest of the day. Whenever any actor or crew member walked past the snack area, he or she reached out an arm - often without even slowing down - to grab some morsel.

As the lab's representative to the movie company, I spent what seemed like every waking hour on the set while the film makers were there during that week in February, just in case something went wrong. But you can't tell much about a movie from watching it being made. I watched Keanu Reeves beat his fists on a garage door and shout the name "Shannon!" approximately 748 times. (Okay, that's not an actual count.) I think I understand why he was shouting, but I'll have to wait for the movie to find out what comes before and after to know for sure.

When they came back in April to finish shooting the scenes that take place at Mount Weather, and also at the FBI Counter-Terrorism Center (otherwise the vault that serves as control room for CWDD), things were a bit more organized. By that time, they were shooting indoors for what they called "pick-up shots" - those two- or three-second long glimpses of equipment or faces. One included the hydrogen tank run amuck. For that scene, the tank, filled with water, bubbled and steamed while three or four very healthy crew members jiggled it to make it look as if it were shaking under the increasing pressure. Meanwhile, two other crew members, just out of camera range, tossed papers in front of air jets to make them swirl around.

While that indoor shooting was going on, another camera crew was outside to film the big evacuation scene. This comes at the end of the film, and I'll try not to spoil the ending for you too much: For reasons not given here, about 200 people spill out of the laboratory, running for their lives. Most of these were Argonne employees or their relatives, and they ran down a 300-foot ramp for the cameras - and then trudged back up the ramp to do it again. Fortunately, this scene was accomplished in about six hours, so the people made the trek only about two dozen times - just enough to dim enthusiasm for careers as extras.

But at least a couple of hundred Argonne employees who served as extras in that and other scenes throughout the movie, will be looking to see themselves on the big screen when "our" movie, "Chain Reaction," debuts this summer. I'm not in the movie, but I'll be in the theater, and I hope you are too.