b'C H A P T E R 8T H E R EA CT O R Z O O G O E S C R I T I C A Lfin fires reached the ears of Dr. Doan, trolled equipment, operators opened Phillips took the MTR up to its fullwho reportedly issued a terse memoran- the lid of the reactor and transferred power of 30 megawatts on May 22,dum stating, There will be no more the hot fuel into lead-lined containers. 1952, another landmark day at theparaffin box fires. And apparently, These were lowered into a water- f i ll ed N RTS. The MTR was ready in Au g u s tthere were none. 9 trough, called a canal, where the con- for its mission to assist other reactortainers ejected their fuel elements designers by testing the materials ofAnother aspect of safety was for reac- under cover of sixteen feet of water. which their reactors would be composed.tor operators to understand exactly how Workers, shielded by the water, leanedneutrons moved about inside the reac- over the canal with long-handled tools The first reactor the MTR assisted wast or . The one hundred openings led to and moved the fuel to its resting place. the Rickover reactor five miles up thedi f ferent positions near the core or in The fuel, referred to as green road, the S1W (S for submarine, 1 forthe graphite around it. Flux differed at because it was fresh from the reactor, first prototype, W for Westinghouse).every spot, which was desirable emitted gamma radiation and lit up the Westinghouse physicists had deter-because not all experiments would water with the soft glow of Cerenkov mined that the predominant source ofneed the same exposure. The scientists r a d i ati on. could tailor an experiment to the mostappropriate flow of neutrons. The reac- After about three months in the canal,tor designers at Oak Ridge had predict- the fission products with short halfed where the flux would be weak or lives lost their radioactivity, leavingintense. Now their work had to bethe fuel safer to handle. Wo r k e rs td. t eseloaded the fuel into a special cask andtrundled it over to the Chem Plant,Technicians placed tiny strands of which recovered its unused U-235.cobalt wire in hundreds of locations inthe graphite and inside the core, gain-ing access via small holes in the beryl-lium reflector. The reactor was made togo critical for a few minutes to irradi-ate the cobalt. The cobalt wires werewithdrawn and sent to a laboratory NRTS News, August 1968down the hall for counting. Measuring Two versions of the MTR canal. Above, as depictedinstruments could detect how many in Site newspaper; left, a technician poses withatoms in each wire had absorbed neu- cutie pie, a beta and gamma radiation detector. Histrons. After months of doing this, the colleague withdraws capsule of cobalt-60. Lightsphysicists plotted a map of the MTRs and tools dangle down side of canal.neutron flux. It pleased the Oak Ridgedesigners to learn that their predictionshad been reliable. 10Handling spent fuel also required safe-ty procedures. When the reactor wasfully in business, the operators shutdown to replace the fuel about everyseventeen days. Using remotely-con-INEEL 57-53426 9'