‘Never work for a man who has electricity in his barn. You’ll be up all
The energy to where Robyn and I were headed was all Orwellian nuclear. It wasn’t in Victor, The End of the Trail, home of the Knot Pine Supper Club, and the Big Hole BBQ. It wasn’t in the Snake Range Targhee National Forest, Land of Many Uses. Nor in the Swan Valley, an Idaho Gem Community. Nor was it along the Big Lost River, nor the Four Winds Saloon nor the Big Butte in Butte City. Before Robyn and I found the energy, we would avoid engaging in the twenty-seven prohibited activities, at the rest stop overlooking the Snake River, and pass through endless amber waves of grain and green groundswells of potatoes, combines and dust devils and windmill farms, and the smell of a dead skunk. As we swerved around the dead porcupine, a bird bounced off our windshield. Manage Wildlife.
“Once I lose my mind completely, I can concentrate on fly-fishing.” I said.
We pulled into Arco up South Front, and took a left onto West Grand. First loan free. Future Home of the Lost River Medical Center. No Fireworks. But there had been, of course. The first clue was a restaurant we passed. Pickles Place- Home of the Atomic Burger. A second arrived with Kaolin, the owner of the Deli Sandwich Shop.
“The #20 all meat combo on a white bun is the local favourite.” She said. Robyn and I ordered an eight-inch submarine, and asked her to cut it in half. Not all the numbers were big in Arco. The 2010 census recorded 417 households, with a median income of $27,993. One of its only physical features was Number Hill, the face of a rocky promontory where every Butte County High School class had painted its graduation year on the face since 1920. Kaylyn had three sons, each at a different Idaho university. She told us some of the history of her town.
“It was the first city in the world to be lit by atomic energy.” She said. “Even if it was for only five minutes.” Originally known as Root Hog, the town had materialized at the crossroads of two stagecoach lines, along the Big Lost River. The civic leaders applied to the U.S. Post Office for the name of ‘Junction,’ but the Postmaster General chose to call it after a German inventor of radio transmission vacuum tubes. Kaylyn didn’t mention the other history, the scary one.
In 1957 the Army began constructing the SL-1, an experimental prototype nuclear reactor designed to produce electric power for remote Arctic stations. It was conceived as a 3MW boiling water reactor that used highly enriched uranium fuel and standard components transportable by air, and requiring a minimum of on-site construction. Simple.
The reactor building was quarter inch steel, almost forty feet wide and fifty feet high. Access was by ordinary doors. The system operated at three hundred pounds per square inch, with a small core assembly of forty fuel assemblies, which gave the central rod an abnormally large reactivity. It was controlled by a sixty-ton crane, with a five-inch steel shield and a nine-inch thick lead glass window to protect the operator.
The SL-1 was shut down on December 21, 1960, to repair a problem with sticking control rods that had plagued the reactor for the previous two months. Its restart occurred on a Tuesday, January 3, 1961. It was cold in the Idaho desert that day, about 27 Celsius degrees below zero.
At 9 pm, three plant workers entered the reactor compartment to reattach the control rods to their drive mechanisms. When Army Specialist John Byrnes, 27 years old, manually lifted the eighty-four pound main central control rod, it became stuck in the extreme cold and, in breaking it loose, he accidentally withdrew it 26.25 inches, 3.25 inches too far. Actually, Byrnes didn’t withdraw it the final 3.25 inches. At 23 inches the exposed rod emitted a huge integrated neutron flux, instantaneously sending the reactor prompt critical. The core fuel rod took only 100 ms to travel the final 3.23 inches. Fuel material reached explosive vaporization temperature, fuel plates swelled and cladding failed. The core power level peaked at 20,000MW for 4milliseconds, forming the large steam bubble that lifted the surrounding mass of water at 50 meters per second. The resultant pressure wave water hammered into the core head 34 milliseconds later, ejecting the head shielding at 10,000 pounds per square inch of pressure, and propelling the pressure vessel out of its support structure at 160 feet per second. The entire five-ton reactor vessel and the upper control rod drive mechanisms jumped ten feet skyward, to collide with the overhead crane and the ceiling of the reactor building, before settling back into their original positions.
Specialist Byrnes was killed instantly by the steam and water that sprayed him onto the floor. The 26 year-old shift supervisor, Navy Seabee Construction Electrician First Class Richard Legg had been standing on top of the reactor vessel. The withdrawn central control rod impaled him through his groin and exited his shoulder, launching him into the air, and pinning him to the ceiling.
The third man, a 22 year-old trainee named Richard McKinley, was later found alive, but he died en route several miles to nowhere, and was returned to the SL-1 hot zone. The nurse who accompanied him was found to have received a significant radiation dose and years later diagnosed with some disease believed to have resulted from her exposure. Even if the three men had not died of traumatic injuries, their radiation exposure from the nuclear excursion would have still left them with no chance for survival. The body of Specialist Byrnes was left on the floor for another day until a recovery operation could be planned; that of Electrician First Class Legg would dangle from the ceiling for another six days.
The corpses, once removed, were emitting over 400 rad/hr, too hot for a normal burial. All were entombed in lead-lined caskets, sealed with concrete, and placed in metal vaults with a concrete cover. Other remains buried in the Idaho desert may or may not have been human. The radioactive gold 198Au from Byrnes's gold watch buckle and copper 64Cu from a screw in his cigarette lighter later confirmed that SL-1 had indeed gone prompt critical.
It was the world's first (and the only American) fatal reactor accident. The cleanup of at least 35 acres of poisoned scrubland continues to this day.
“Did you know that the reactor would go critical if the central control rod were removed?” A scientific inquiry had asked, after the accident.
“Of course.” Replied the reactor operators. “We often talked about what we would do if we were at a radar station and the Russians came. We’d yank it out.”
The ambulance used in the transport of Richard McKinley was later decontaminated, and driven for several years at the Eastern Idaho State Fair. It’s a Feeding Frenzy.