b'C H A P T E R 15T H E S L-1 R EA CT O RThe Army planned to train its future The last task was to insert forty-four Reconnecting the drive mechanismsDEW Line crews at the SL-1, so CE new cobalt flux wires into the core for involved several steps, one of whichran the reactor with a military crew. later mapping of the reactors neutron was to lift the control rodmanuallyThe Army and the Air Force sent flux. The January 3 day shift inserted about three inches out of the reactor. Attrainees; the Navy, interested in the the flux wires. To gain access to the the top of the control rod was a smallpotential of the SL-1 for Navy mis- reactor core, they had moved out of the ball. A gripper from the drive mecha-sions, sent Seabees. The mixed way several large concrete shielding nism latched onto this ball, completingcadres trained together and rotated to blocks that ringed the top of the reactor. the connection between the rod and theIdaho after several months of instruc- Then they disconnected the control rods rest of the mechanism and its motor.tion at Fort Belvoir, Virginia, where the from their drive mechanisms, these alsoArmy operated its prototype Stationary being in the way. It would fall to the 4Medium-Power (SM-1) reactor eigh- p.m. shift to reconnect the control rodsteen miles from the White House. to the drive mechanism. 9The SL-1 went critical for the first time In miserably cold weatherthe temper-on August 11, 1958, and produced its ature was headed for seventeen degreesfirst electricity two months later on below zero that nightthe three-manOctober 24. Thereafter, the rhythm of crew arrived from Idaho Falls and setwork involved running the reactor for to work, the only workers at the SL-1periods ranging between one and six area. As usual for night shifts, noweeks and then shutting down for train- guards were posted at the entry gate,ing in maintenance and repair or to which the day-shift cadremen hadinstall improvements. The first cadre locked behind them as they left.had been trained, tested, and certifiedby May 1959, and many others fol- INEEL 58-2001lowed. CEs Christmas routine was to Above. Enclosed stairwayshut down the reactor, celebrate the from SL-1 support building toholiday, and then do annual mainte- operating floor of reactor silo.nance tasks before the next start-up. 8 Left. The control rod drivemechanism. Note cruciformAccordingly, on December 23, 1960, shape of control rod (bottomCE shut down the reactor. Crews of drawing).returned on December 27, reporting towork in three shifts around the clock.Start-up was scheduled for January 4,1961. The men calibrated instrumentsand attended to the valves, pipes, andpump that circulated coolant waterthrough the reactor. To do part of thiswork, they lowered the water level inthe reactor about two feet.INEEL 61-2031 4 1'