The water activation experiment serves as a demonstration of the creation of radioactive isotopes from nuclear reactions with fast neutrons in pure water. The main reaction product, N-16, is important from the radiation protection standpoint, as it emits energetic and highly penetrating gamma rays, in water-cooled fission and fusion devices. Conversely, measurements of the activities of the product radioactive isotopes represent an independent method of monitoring of the reactor power, leak detection, etc.