Of these, the Soviet Union performed 116 tests in the atmosphere, and 340 underground. In addition, the Soviet Union discarded equipment that included high-purity plutonium that would have provided materials and information that could lead to a relatively sophisticated nuclear device if it had been found. Hecker, who helped pioneer cooperation with his counterparts in the Soviet and later Russian nuclear weapons laboratories, used personal connections to push for action. He succeeded in enlisting the cooperation of Russian nuclear scientists who had been involved in the testing program in Kazakhstan before the Soviet collapse. Serious logistical difficulties were just one reason the Semipalatinsk operation took so long.