Tales from the Nuclear Age:
Copyright © 2010 by Charles Glassmire
Jun. 18, 2010
The SL-1 Incident
The year was 1957 and the nuclear business was growing rapidly, amid an optimistic feeling that America could do anything. The U.S. Navy was building a nuclear powered submarine under the guidance of Admiral Hyman Rickover. The U.S. Air Force was designing and testing a nuclear powered aircraft. At the Joint Chiefs, the U.S. Army wanted badly to get into the nuclear game, but they had no demonstrated need. The nuclear business was deemed quite safe. Years later the claim was always made that no one had ever died in the commercial nuclear power industry. As far as it went, that was true. But the statement always emphasized the word “commercial”. It didn’t include nuclear facilities operated by the U.S. Army.
The Army operated a radar system perched on the permafrost, stretching across the Arctic tundra snows of Alaska and Canada, and on to Greenland. The system was watching over the horizon to the Soviet Union for a possible aircraft attack against America. It was called the Distant Early Warning Line, or DEW line for short. Comprised of small stations clustered in the endless northern winter, each station required tons of diesel fuel and gasoline to run the equipment and keep personnel from freezing. The Arctic winters were long and dark, and the fuel had to be constantly shipped in by truck and airplane. Sometimes weather prohibited timely delivery of the vital material. It was a perfect application for a small nuclear reactor power source which could supply electricity and run for a long time before requiring refueling.
A completely safe reactor was requested. The Army wanted one which could be transported, assembled and operated by a trained G.I. without incident, and impossible to melt down. Power level was to be 1000 Kilowatts. So they approached one of the U.S. nuclear facilities, the Argonne National Laboratory, to design a small stationary reactor, generating electricity for a three year period before needing a new fuel load of Uranium. The reactor could be transported to a site on the back of a truck, assembled there and then become stationary in operation.
So Argonne came up with a design. It couldn’t use concrete shielding, since that material would freeze quickly when pored in extreme cold. So they choose an insulator of round steel punchings mixed with gravel to absorb the gamma radiation generated during operation. There was no containment vessel, just a 48 foot high cylindrical building to house the plant, with the control room situated beside the reactor building. The vessel was to sit on two-foot high piers to separate it from the permafrost below, introducing an air space underneath to prevent melting the frozen ground. Access from the Control Room was via an outside staircase winding up and around the building. Argonne chose a Boiling Water Reactor (BWR) design, with a single main control rod in the center to vary the reactor power generation (“because it was easier” they later testified). No reactor had ever been built with only a single control rod. There were four peripheral rods which were only used to level out the neutron flux somewhat. Combustion Engineering was given the contract to construct the reactor.
The test reactor was named the “SL-1” for “stationary low-power reactor number one”. It was built at the Idaho Nuclear Reactor Test Station (NRTS) in a rather remote location. The reactor began generating electricity in October of 1958. Crews were trained at Fort Belvoir Virginia, and since the Navy and Air Force wanted in on the action, crews were chosen from all three services. Training was four months of classroom and four months of reactor (simulator) operation.
On the night of January 3rd, 1961, there were three men working the evening shift starting at 4 p.m. Army private Jack Byrnes from upstate New York, had falsified his birth certificate to enlist early. He was a bit of a hell raiser, always broke, favoring fast cars and lots of drinking. He was married by the age of 19, but rumor had it his marriage was troubled and “sliding downhill” as one chronicler put it later. Dick Legg was a Navy Seabee from Michigan and a bit of a joker. He was sometimes known to set off the deafening reactor SCRAM alarms and then laugh hysterically. One learned never to let Dick stand behind you as he had earned the nickname “Goosey”. He and Byrnes had occasional fistfights when in their cups, and argued over prostitutes and other such personal matters. In the previous month of December 1960 Byrnes performance review decided he was “not ready for promotion”.
The third crewman that evening was Richard McKinley. He was still in training from the U.S. Air Force, and was on duty to observe and learn from the other two.
The SL-1 had been running successfully since 1958, and in late December had been shut down for holiday recess and maintenance. Crews were calibrating instruments and checking valves and piping. The water level in the reactor had been lowered two feet. The day shift had just inserted forty four new Cobalt flux wires into small holes in the core. To do this the top of the core was exposed and massive shields were moved out of the way. The Control Rods were disenguaged from their drive mechanisms. The night shift was now walking on the top of the actual core to reconnect the rods and move the shielding back into place.
At 7 p.m. that evening, Byrnes wife Arlene called her husband and spoke on the telephone. She told him that their marriage was ended. She was finished and wanted out. She also wanted half of his next pay voucher. She told him not to come home ever again. She called three more times that evening trying to get him again on the phone. But no one answered the phone. There was no security guard at the reactor during the evening shift. He went home at 4 p.m! Unable to contact anyone at the site, she called the operator and told the operator:
“There must be something wrong at SL-1”. Her message was duly noted in the event log.
At 9:01 p.m. that evening the Central Fire Station at NRTS received a signal from SL-1. It was a dash followed by two dots on the alarm system. This signal also went to the NRTS Security Center. It meant there was a fire at SL-1!
It took a fire truck nine minutes to arrive at the site. When the fireman jumped off the truck they noticed an eerie calm in the dark reactor yard. No fire was visible, only a steam trail from the reactor building which was normal in cold weather. The reactor was supposed to be manned 24 hours per day. It seemed deserted. There was no one in the control room, however, radiation alarms were sounding all over the reactor building. As they tentatively crossed the yard and approached the access stairway, their radiation meters began rising and as they got to the stairway the needles went off scale! They quickly withdrew to await health physics personnel with high level radiation detectors. …
(to be continued…)