Nuclear reactor control system

Claim 1

IN A NCLEAR REACTOR HAVING AN ACTIVE CORE PORTION CAPABLE OF SUSTAINING A CONTROLLED NUCLEAR FISSION CHAIN REACTION, A CONTROL SYSTEM FOR THE REACTOR COMPRISING MEANS DEFINING A CLOSED PATH FOR THE CIRCULATION OF A LIQUID THERETHROUGH, A PORTION OF SAID CLOSED PATH WITHIN THE REACTOR VESSEL COMPRISING A PLURALITY OF VERTICAL PASSAGES EXTENDING UPWARDLY THROUGH AND ABOVE SAID ACTIVE CORE PORTION AND DISPOSED ACROSS SAID ACTIVE CORE PORTION, A ROD-SHAPED POISON MEMBER DISPOSED IN EACH OF SAID PASSAGES, EACH SAID ROD-SHAPED MEMBER HAVING AN OUTSIDE DIAMETER LESS THAN THE INSIDE DIAMETR OF ITS RESPECTIVE PASSAGE TO PROVIDE CLEARANCE FOR THE FLOW OF LIQUID THROUGH SAID PASSAGES, MEANS FOR CIRCULATING A LIQUID IN SAID CLOSED PATH UPWARDLY THROUGH SAID VERTICAL PASSAGES AT SUCH VELOCITY AS TO NORMALLY HOLD SAID ROD-SHAPED POISON MEMBERS IN THE UPPER END OF SAID PASSAGES ABOVE SAID ACTIVE CORE PORTION, MEANS FOR CONTROLLING THE FLOW OF LIQUID THROUGH SAID CLOSED PATH TO REGULATE THE ELEVATION OF SAID ROD-SHAPED POISON MEMBERS IN SAID PASSAGES AND REGULATING MEANS OPERABLE TO REVERSE THE DIRECTION OF LIQUID FLOW THROUGH SAID PASSAGES TO DRIVE SAID ROD-SHAPED MEMBERS DOWNWARDLY THEREIN INTO SAID ACTIVE CORE PORTION, AND WHEREIN THE RELATIVE OUTSIDE DIAMETER OF SAID ROD-SHAPED POISON MEMBERS AND THE INSIDE DIAMETER OF THEIR RESPECTIVE PASSAGES IS SUCH AS TO PROVIDE GREATER CLEARANCE BETWEEN SAID MEMBERS AND THEIR PASSAGS ADJACENT THE EFFECTIVE CENTER OF THE ACTIVE CORE PORTION THAN BETWEEN SAID MEMBERS AND THEIR PASSAGES ADJACENT THE PERIPHERY OF SAID ACTIVE CORE PORTION, WHEREBY IN RESPONSE TO A REDUCTION IN THE RATE OF FLOW OF LIQUID UPWARDLY THROUGH SAID PASSAGES THOSE ROD-SHAPED POISON MEMBERS ADJACENT THE CENTER WILL PRECEDE THOSE ROD-SHAPED POISON MEMBERS ADJACENT THE PERIPHERY DOWNWARDLY INTO SAID ACTIVE CORE MEMBER.