Pebble-bed Reactors (IMAGE) Texas A&M University Caption Pebble-bed reactors use passive natural circulation to cool down, making it theoretically impossible for a core meltdown to occur. Credit Dr. Jean Ragusa and Dr. Mauricio Eduardo Tano Retamales/Texas A&M University Engineering Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.