Spacer with steam separator

In a cross point spacer including a spacer grid for defining surrounding cells in a fuel rod matrix interior of a fuel bundle at selected elevations within said fuel bundle comprising:

• pluralities of normally aligned members for extension between respective rows and columns fuel rods for forming a first part of bounding cells around the fuel rod matrix of a fuel bundle;
• vertically aligned subchannel tubes connected to said and members to form a second part of bounding cells around the fuel rod matrix of a fuel bundle and to form a mechanical interconnection to said grid members and to define subchannel flow volumes at the subchannel between adjacent fuel rods;
• peripheral attachments interior of each of said subchannel tubes for providing a spiral flow to at least some of the steam water mixture flowing through each of said subchannel tubes whereby at least some water is centrifugally classified from said steam flow through said subchannel tubes upon discharge of said coolant flow from said subchannel tubes;
• and
• said peripheral attachments interior of said subchannel tubes defining a central flow free volume in said subchannel tubes for providing the upward unobstructed flow of coolant within said tubes.

A method of constructing a cross point spacer including a spacer grid for defining surrounding cells in a fuel rod matrix interior of a fuel bundle at selected elevations within said fuel bundle comprising:

• providing pluralities of normally aligned members for extension between respective rows and columns fuel rods for forming a first part of bounding cells around the fuel rod matrix of a fuel bundle;
• providing vertically aligned subchannel tube connected to said members to form a second part of bounding cells around the fuel rod matrix of a fuel bundle and to form a mechanical interconnection to said grid members and to define subchannel flow volumes at the subchannel between adjacent fuel rods;
• placing peripheral attachments interior of said subchannel tubes for providing a spiral flow to at least some of the steam water mixture flowing through said subchannel tubes whereby at least some water is centrifugally classified from said steam flow through said subchannel tubes upon discharge of said coolant flow from said subchannel tubes;
• and
• defining in said peripheral attachments interior of said tubes central flow free volumes in said subchannel tubes for providing the upward unobstructed flow of coolant within said tubes.