A train trip two miles into Yucca Mountain

"If you trip and fall in the tunnel, you're going to the hospital," the tour guide was saying, holding on to the luggage rack as a tour bus rocked north on Highway 95.

He was describing safety measures followed at the tour's destination: The Yucca Mountain nuclear waste repository site, where 77,000 tons of high-level nuclear waste are expected to be shipped starting in 2010.

Back at the Yucca Mountain Science Center at the Meadows Mall in Las Vegas, he had earlier explained the use of the "self rescue" breathing devices (which will change deadly carbon monoxide into safe carbon dioxide), helmets, eye protection, ear plugs -- all required safety gear for anyone entering the tunnel.

The red, white and blue Coach USA bus rolled past chain-link fence pens near the highway as it approached the security checkpoint at Mercury -- entrance to the restricted Nevada Test Site -- carrying about 50 businesspeople on a tour organized by the Northern Nevada Development Authority.

"Those fenced-in areas are for the protesters," explained the guide, Patrick Rowe, a senior engineer with the Yucca Mountain Site Characterization Office. "When there's enough of them they call in a bus and haul them up to the county seat at Tonopah."

At the checkpoint, a muscular guard in desert camouflage pants and tan T-shirt climbed on the bus and checked ID tags. Everyone on the tour had passed a background check before they were OK'd to see 5,000-foot-high Yucca Mountain.

The bus rolled by the scattered, moth-balled buildings and engine test stands of Area 25, where a project from 1957 to 1972 was aimed at creating a nuclear motor to enable interplanetary space travel.

"They were trying to beat Russia to Mars," explained Rowe.

Approaching the north portal of the Yucca Mountain tunnel, the bus rolled by 20-foot piles of "muck," dry rocky debris pulled from the mountain. Square white buildings and chain-link fences have been constructed on ground made level with the "muck."

Employees, who work four 10-hour shifts each week and are brought from Las Vegas and Pahrump on the Coach USA buses, walked the site in denim and khaki work clothes, one of them smoking by a pickup truck.

Inside the "change house," workers in neon green and orange vests visited the vending machines before heading into the tunnel. A plastic tool box by the door was covered in patriotic stickers.

Riding into the perfectly round, 25-foot diameter tunnel on the "white ride" train, the wind was at the tour's back. A 66-inch duct along the ceiling pumps air out of the tunnel, sucking clean air in the entrance at 160,000 cubic feet per minute.

The gray stone walls of the tunnel were covered with slightly rusty steel support ribs near the entrance, while farther in the walls were bare.

"They didn't know what to expect," explained media liaison Karen Threlkeld, "so they were overly cautious at first."

Parallel to the tracks ran an 8-foot-high framework of white steel beams supporting the conveyor belt which removed rock as the tunnels were dug. A $13 million tunnel boring machine built by a company in Kent, Wash., for Yucca Mountain had drilled into the hillside, going west for two miles before turning left and heading south for two miles, then back to the east and out. The rig was equipped with cameras which photographed every fracture and crack. The machine, which set a world record by borrowing almost 200 feet in 24 hours, rests outside the south portal where it came out.

Many of the tunnel walls, which sometimes were so smooth they could be used as a skateboard halfpipe, were peppered with reinforcing William bolts.

Each time the train came to one of the raised yellow platforms on the right, the driver honked twice and stopped the train before rolling on.

As the train passed a diagonal intersection with the "cross drift" tunnel, work crews watched under bright halogen lights. A green plastic eye-wash station sat on a table next to a yellow and red beverage dispenser. Yellow tarps with dusty clear windows hung from white steel frames.

The crews are working on removing a block of stone which will be sent to the University of California at Berkeley for testing. Once crews remove a sample from Yucca's walls, custody of the sample transfers to a special sample-management team, who keep tabs on every piece.

Two miles in, where additional tunnels are expected to store the nation's nuclear waste about 1,000 feet below the peak's summit, Alcove 5 houses the eight-year test of the effect of heat on the rock.

After four years of heating the rock in a mock canister-storage alcove, the heaters were turned off Jan. 14, 2002. The surrounding stone was heated to more than 400 degrees -- estimated to be about the temperatures created by the stored waste. Energy to heat the rock cost $396,332 over the 35,715 hours the heaters were on.

"Before we did any of these tests we made predictions about what would happen," explained Russ Dyer, formerly the project manager for the Yucca project and now a senior policy adviser. "So far what we've seen has been pretty consistent with what we expected."

Alcove 5, with a steel floor and walls covered by aluminum insulation to protect workers during the four years of heat, was the end of the line for the tour.

When the "white ride" rattled back up the tracks toward the glaring white-blue of daylight, the wind, smelling of diesel exhaust and the cologne of tour members, was strong coming in the tunnel.