b'P ROVING THE P RINCIPLEFor low-power critical facilities, includ- reviews of procedures. Some reactors atThe accident inspired the AECsing the ones at the NRTS, the AEC the Site went two years before starting Advisory Committee on Reactorordered that all operating and shut- up again. There were committees, and Safeguards (ACRS) to continue itsdown procedures be written in detail. everyone was reviewing procedures andstrong interest in learning more aboutJoe Hensheid, supervisor of the ETR developing formalized sign-offs. It the type of destructive accident repre-Critical Facility, recalled: 11 turned into a totally new way of doing sented by the SL-1. The SPERT pro-business with reactors. Procedural doc gram particularly received strong-The SL-1 accident was a big watersheduments that originally had been two support. The ACRS was looking towardpoint. Up until then, our detailed proce - the future when power reactors wouldpages long were expanded into thickdures werent much, but we were able tobooks, and all activity became rigidly contain far more fuel and a biggerget a lot done in a short amount of time.prescribed.those years of committee inventory of fission products than theAfter SL-1, the reactor [I worked with] meetings with no experiments were hardSL-1. It requested that safetywas shut down, and we had many, manyon everyone. researchers look for a way to build12large reactors so that a neutron distur-bance or excursion in one region of fuelcould not propagate to the rest of it. Insuch an event, the ACRS hoped thatdestruction of more than a small partof the reactor is demonstrably impossible. 13The SL-1 disaster had no apparent Left. ML-1 Test Building at Army Reactor Area-IV. impact on the A rmy s plans for smallPower conversion component faces the door. Top of nuclear power plants. In the immediatecircular reactor component is behind it. Below. aftermath of the accident, it ordered itsAerial view of ML-1 test area. Control trailer is in Portable Medium-Power reactor, operat-lower center behind shielding berm. Reactor was in ing on the Greenland ice cap, to shutTest Building in upper center of view. down pending a review of its controlINEEL 62-6216 rods and operating procedures. T h eArmy continued its experiments inIdaho. Work at the GCRE had producedthe data for a pin-type fuel design forthe A r m y s mobile prototype. Amon t h after the accident, Aerojet-General in D o wne y, California, loaded the proto-type ML-1 onto an Army semi-trailerand hauled it to Idaho for field testing. 14 The little reactor went critical for thefirst time later in 1961 and ran as apower plant for the first time onSeptember 21, 1962, making history asthe smallest nuclear power plant onrecord to produce electricity. It reachedfull-power operation on February 28,INEEL 63-16661 5 4'