Nuclear reactor and method for refueling same

Claim 1

A NUCLEAR REACTOR COMPRISING A REACTOR CORE FORMED OF A PLURALITY OF ADJACENT, GENERALLY VERTICALLY EXTENDING, ELONGATED CORE ELEMENTS, SAID CORE ELEMENTS RESIDING IN A PLURALITY OF REFUELING ZONES, A PRESSURE VESSEL SURROUNDING SAID CORE, SAID PRESSURE VESSEL HAVING A HEIGHT LESS THAN TWICE THE LENGTH OF SAID CORE ELEMENTS, SAID PRESSURE VESSEL ALSO HAVING FORMED THEREIN A PLURALITY OF GENERALLY REGULARLY SPACED ACCESS OPENING LOCATED ABOVE SAID CORE ACROSS THE TOP PORTION OF SAID PRESSURE VESSEL, A SEPARATE ACCESS OPENING BEING OF LYING EACH REFUELING ZONE, SAID ACESS OPENINGS BEING OF SUFFICIENT SIZE TO OVERLIE A PLURALITY OF CORE ELEMENTS AND THE TOTAL CROSS SECTIONAL AREA OF ALL OF SAID ACCESS OPENINGS BEING SUBSTANTIALLY LESS THAN THE CROSS SECTIONAL AREA OF SAID REACTOR CORE, NOZZLES EXTENDING VERTICALLY UPWARD FROM SAID ACCESS OPENINGS, SAID NOZZLES PERMITTING THE CORE ELEMENTS WHICH DIRECTLY UNDERLIE SAID ACCESS OPENINGS TO BE LIFTED AXIALLY THERETHROUGH AND THEREBY WITHDRAWN FROM THE REACTOR, CONTROL RODS BEING PROVIDED IN AT LEAST CERTAIN OF SAID REFUELING ZONES, SAID CONTROL RODS BEING AXIALLY ALINGED WITH THE ACCESS OPENING FOR THE ZONE, AD REMOVABLE CONTROL ROD DRIVE MEANS DISPOSED WITHIN THE NOZZLES ABOVE SAID CERTAIN ZONES, SAID ACCESS OPENINGS BEING OF SUFFICIENT SIZE TO PERMIT ENTRY OF CORE ELEMENT HANDLING MEANS FOR REMOVING THE CORE ELEMENTS FROM THE ASSOCIATED CORE ZONE.

Claim 3

A METHOD FOR REFUELING A ZONE OF A NUCLEAR REACTOR INCLUDING A PRESSURE VESSEL HAVING DISPOSED THEREWITHIN A REACTOR CORE MADE UP OF A PLURALITY OF ELONGATED VERTICALLY DISPOSED CORE ELEMENTS AND DIVIDED INTO A PLURALITY OF REFUELING ZONES, ACCESS TO EACH OF THE REFUELING ZONES BEING BY AN ACCESS OPENING IN THE PRESSURE VESSEL OVERLYING AND GENERALLY CENTRALLY DISPOSED OF EACH ZONE, THE CROSS SECTIONAL AREA OF THE ACCCESS OPENING BEING SUBSTANTIALLY LESS THAN THE CROSS SECTIONAL AREA OF THE UNDERLYING ZONE, WHICH METHOD COMPRISES REMOVING FROM THE REACTOR ALL OF

Claim 4

A METHOD FOR REFUELING A ZONE OF A NUCLEAR REACTOR INCLUDING A PRESSURE VESSEL HAVING DISPOSED THEREWITHIN A REACTOR CORE MADE UP OF A PLURALITY OF ELONGATED VERTICALLY DISPOSED CORE ELEMENTS AND DIVIDED INTO A PLURALITY OF REFUELING ZONES, ACCESS TO EACH OF THE REFUELING ZONES BEING BY AN ACCESS OPENING IN THE PRESSURE VESSEL OVERLYING AND GENERALLY CENTRALLY DISPOSED OF EACH ZONE, THE CROSS SECTIONAL AREA OF THE ACCCESS OPENING BEING SUBSTANTIALLY LESS THAN THE CROSS SECTIONAL AREA OF THE UNDERLYING ZONE, WHICH METHOD COMPRISES REMOVING FROM THE REACTOR ALL OF