Fuel assembly supporting structure. [PWR]

Patent · Tue Dec 14 04:00:00 EST 1976

OSTI ID:7327146

Aisch, F W; Fuchs, H P; Knoedler, D; Steinke, A; Steven, J

For use in forming the core of a pressurized-water reactor, a fuel assembly supporting structure for holding a bundle of interspaced fuel rods, is formed by interspaced end pieces having holes in which the end portions of control rod guide tubes are inserted, fuel rod spacer grids being positioned by these guide tubes between the end pieces. The end pieces are fastened to the end portions of the guide tubes, to integrate the supporting structure, and in the case of at least one of the end pieces, this is done by means which releases that end piece from the guide tubes when the end pieces receive an abnormal thrust force directed towards each other and which would otherwise place the guide tubes under a compressive stress that would cause them to buckle. The spacer grids normally hold the fuel rods interspaced by distances determined by nuclear physics, and buckling of the control rod guide tubes can distort the fuel rod spacer grids with consequent dearrangement of the fuel rod interspacing. A sudden loss of pressure in a pressurized-water reactor pressure vessel can result in the pressurized coolant in the vessel discharging from the vessel at such high velocity as to result in the abnormal thrust force on the end pieces of each fuel assembly, which could cause buckling of the control rod guide tubes when the end pieces are fixed to them in the normal rigid and unyielding manner.

• Assignee: Kraftwerk Union Aktiengesellschaft
• Patent Number(s): US 3997394
• OSTI ID: 7327146
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
DESIGN
FUEL ASSEMBLIES
MECHANICAL STRUCTURES
PWR TYPE REACTORS
REACTORS
SUPPORTS
WATER COOLED REACTORS
WATER MODERATED REACTORS