b'P ROVING THE P RINCIPLEto be built so that if an accident worst possible weather conditions.occurred, the fission productsshould Then they calculated the consequencesthey escape the cladding and the reactor if the fuel melted. They speculated thatpressure vesselwould not pass it would drop to the bottom of the pres-beyond a third barrier called a contain- sure vessel, melt through it, fall to thement vessel. Typically, containment concrete floor and basements beneathvessels were dome-shaped and con- the power plant, burn through the con-structed to withstand the pressures that crete, and proceed through the earth tomight result from a steam explosion. China, or at least in the direction ofChina, until the fuel cooled naturally.In the new plants, the reactor core con- Worse, steam pressure might rupturetained tons of fuel. Analysts imagined the containment vessel and send fissionthe consequences if the coolant somehow products into the atmosphere whicheverfailed to carry away the heat of fission- way the wind was blowing. Havinging. Suppose a pipe leaked or broke? T hebreached their triple containment, theS PERT tests had proven that such a situ- fission products would be an immediate ation would easily put a stop to the chain hazard in the air and could eventuallyreaction: the loss of pressure would contaminate soil and water supplies. 13allow the water to turn to steam; thelower density of steam would fail to New Jersey Central and other licensemoderate the neutrons; and the nuclear applicants were proposing a variety ofreaction would stop. But the radioactive back-up cooling systems that would pre-decay of the fission products inside the vent fuel from ever getting hot enoughfuel elements would continue to produce to head for China. The trouble was thatCutaway illustration of the PBF reactor. heat and continue to need cooling. Even these had not been proven to work.though the decay heat was a small per- None of the safety testing at thecent of the heat of a fissioning reactor, it NRTSor anywhere elsehad tested a1,000-megawatt reactors, far exceeding was enough to melt the fuel and clad la ge-reactor LOCA, the China rany previous AEC demonstration pro- metal, leading to potentially violent Syndrome, or how the many variables injects. The fierce competitive struggle led interactions with water or air. la ge-scale reactor systems would inter- rthe two companies to sell reactors as act. Consequently, AEC regulators had aloss-leader products. The true profitabili- Clearly, more was at stake in a large host of new technical questions. The ty or economic superiority of nuclear commercial reactor. If something hap- Phillips engineers had anticipated manyover fossil fuel plants wasat least at pened to the coolant flow, an emer- of the questions and were ready with athat timedebatable. 12gency back-up system had to send plan. In 1963 Phillips began a $19.4 mil-water to the core and carry heat away. lion program to build a special reactor toThe huge plants presented new safety It was chiefly a matter of engineering, explore LOCAs. The main idea was toproblems. The AECs Division of not physics. load up the reactor and the containmentNuclear Safety, which performed building with instrumentation, operatelicensing and safety reviews of pro- Scientists at Brookhaven National the reactor, and then withhold theposed plants, had thus far dealt with Laboratory attempted to define what coolant to see what happens. 14 plants of much lower power. Even so, might be at stake. They imagined thethe AEC had not permitted them to worst case loss-of-coolant accident The Loss-of-Fluid Test (LOFT) reactorlocate near highly populated areas. (LOCA) in a reactor located very near a was to be a 50-megawatt reactor withAdditionally, the reactor buildings had large city. They elaborated it with the fuel elements clad in stainless steel and1 7 8'