Radionuclides are produced as an unavoidable result of nuclear fission and thermonuclear explosions. The R-12 was a medium-range ballistic missile, capable of carrying a thermonuclear warhead. Each missile was able to deliver three ET.317 thermonuclear warheads. The 14 SSBNs together carry about half of U.S. active strategic thermonuclear warheads. The blast incited international reaction over atmospheric thermonuclear testing. Numerous photographs of various thermonuclear bomb exteriors have been declassified. Theoretically by continuing this process thermonuclear weapons with arbitrarily high yield could be constructed. The Soviet thermonuclear weapons program was aided heavily by Klaus Fuchs. Controlled thermonuclear fusion concepts use magnetic fields to confine the plasma. The scientists at Aldermaston had not yet mastered the design of thermonuclear weapons. With his pivotal role in the development of thermonuclear weapons, Stanislaw Ulam changed the world. It is one of the most closely guarded secrets of a multistage thermonuclear weapon. Vanunu revealed that between 1980 and 1986 Israel attained the ability to build thermonuclear weapons. Lithium-6 from the Beta calutrons was used for research into thermonuclear weapons. It first became practical when incorporated into the secondary of a two-stage thermonuclear weapon.