The thought may not be comforting: MX missiles, each with 168,000 pounds of propellent holding the explosive power of 202,000 pounds of TNT, riding the rails through Utah en route to Hill Air Force Base for maintenance and repair.
But the Air Force officially figures that a person has only a 1-in-3.6 billion chance of being killed in an accident with the missiles.According to Air Force MX safety evaluations, obtained through the Freedom of Information Act by the Deseret News, Utahns are 1,700 times more likely to be killed by lightning.
But the safety assessment still warns of devastation that could kill or injure people for miles if, despite the long odds, a major rail accident and fire on an MX missile train were to occur.
Although earlier plans to base MX missiles in underground railroad and silo systems in Utah's western desert were killed years ago, the Air Force's "Peacekeeper Rail Garrison Plan" now aims to keep 50 to 100 MXs at bases nationwide and in the threat of war disperse them on commercial railways to make them more difficult targets for enemy missiles.
That plan also calls for missiles to be transported to Hill - without their 10 nuclear warheads each - for routine maintenance and repair when problems occur. The federal 1991 budget has money for a new MX storage site at Hill.
The MX missile has had its problems already. Air Force officials feared that an explosion or accidental launch might occur after one of the missiles slipped 6 to 8 inches in its silo at F.E. Warren Air Force Base near Cheyenne, Wyo., in June 1988, but they managed to remove the disabled missile from its silo without incident.
And last September, an MX missile that was making the system's first test as an operational weapons system had to be destroyed shortly after launch when telemetry indicated a problem aboard the four-stage intercontinental ballistic missile.
But Air Force documents say residents should not be overly concerned about any safety problems.
Air Force documents say the missiles are greatly protected by their launch tubes and specially constructed missile launch rail cars. It said tests indicate no danger of explosion apparently exists in head-on rail accidents of up to 60 miles per hour, and rear-end collisions of up to 45 miles per hour.
But a remote chance still exists for a detonation-type explosion of missile propellants in high-speed or side-striking collisions. "Blast and flying debris could kill or injure unprotected persons out to 1,000 feet from the blast," documents said.
They added that resulting toxic fumes of nitrogen dioxide and hydrogen chloride with a concentration of 200 parts per million "might be experienced as far away as 1.6 miles and could be lethal to up to 50 percent of the exposed population."
Lower concentrations resulting in conditions from eye irritation to vomiting "might occur as far as 18 miles downwind."
The Air Force also notes that solid propellants used by missiles "can withstand much higher temperature, shock, crush and other abnormal environments without igniting or exploding than many other chemicals routinely transported on the national rail network and highways" - which also may not comfort residents.
In fact, the Associated Press recently quoted Nelson Ames, head of the Utah Highway Patrol's hazardous response team, saying trucks carrying missile fuel to defense contractors in Utah pose less of a threat than daily shipments of gasoline and propane to the area's service stations.
He said 19 percent of all truck traffic in Utah involves some type of hazardous material. But most hazardous materials shipments are made at night when few people are on the road, as when a truck carrying 14,000 pounds of nitroglycerin for Hercules ran off State Road 83 leading to the Thiokol plant near Brigham City.
However, highly explosive gasoline shipments occur at all hours of the day and in heavily populated areas.
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(Additional information)
A life of risks
Americans face the following odds of dying in an accident:
Auto wreck 1 in 4,000
Fire 1 in 25,000
Drowning 1 in 30,200
Aircraft accidents 1 in 100,000
Falling objects 1 in 160,000
Lightning 1 in 1.3 million
Tornadoes or hurricanes 1 in 2.5 million
MX missile train wreck 1 in 3.6 billion
Figures provided by the U.S. Air Force