Excess pressure rupture preventive system for reactor containers

Purpose: To prevent excess pressure rupture in reactor container. Constitution: Upon occurrence of accident such as in recycling pipeway, if means for removing heat from the primary reactor containers is lost, the inside pressure in the containers gradually rises and the pressure difference between this pressure and the inner pressure in the reactor buildings approaches to a dangerous pressure causing excess pressure rupture. If the pressure exceeds a predetermined value set slightly lower than the above dangerous pressure, a pressure difference gage opens a valve to lower the pressure difference to the predetermined value and, if the pressure difference is lowered below the predetermined value, the pressure difference gage closes the valve. By the repetition of the above operations, the pressure difference can be maintained approximately at the predetermined level. (Horiuchi, T.)