Reactor cooling system for boiling water reactors

A reactor cooling system for boiling water reactors comprising:

• a pressure vessel containing a core of a boiling water reactor;
• a pressure suppression pool filled with a water and disposed to surround the pressure vessel;
• static core injection means including two systems having a capacity in total not less than 100% of the capacity necessary to maintain submergence of said core in said pressure vessel;
• and
• dynamic core injection means including two systems having a capacity in total not less than 100% of the capacity necessary to maintain submergence of said core in said pressure vessel;
• said two systems of said static core injection means each having a water source installed at a position inside the reactor container higher than said pressure vessel, a first core injection line communicating said water source with said pressure vessel, and first valve means provided in said first core injection line and including an isolation valve and a check valve for allowing only a flow of cooing water from said water source of said pressure vessel, and each system having a capacity not less than 50% of the capacity necessary to maintain the submergence of said core in said pressure vessel;
• said two systems of said dynamic core injection means each having a second core injection line communicating said pressure suppression pool with said pressure vessel, a pump provided in said second core injection line, and second valve means provided in said second core injection line and including an isolation valve and a check valve for allowing only a flow of cooling water from said pressure suppression pool to said pressure vessel, and each system having a capacity not less than 50% of the capacity necessary to maintain the submergence of said core in said pressure vessel;
• and
• said first core injection line and said second core injection line being connected with each other at a location downstream of said first valve means and said second valve means.