Babcock Wilcox Canada Ltd.

Jun Tang

Richard G Klarner

Roderick J McGregor

A reactor closure head assembly has guide tube nozzles which are integral with the reactor closure head. A dome-shaped forging having a concave surface is prepared with extra thickness equal to or greater than the desired nozzle height. Nozzles having bores therethrough are machined opposite the concave surface. Weld buttering is applied to the ends of the nozzles, the concave surface is clad with a corrosion resistant layer, and the forging is then heat treated. A guide tube flange is attached to the ends of the nozzles. The surfaces of the nozzle bores are covered with a protective layer which is preferably applied without heating, for example by electrochemical deposition, thereby avoiding the need for subsequent post weld heat treatment.

Reactor head with integral nozzles

A method of hydraulically prestraining the tubes of a once-through steam generator by welding the tubes to their respective tubesheets prior to the application of hydraulic expansion to produce tensile stresses which shorten the tubes an equal and predetermined amount to increase the margin to buckling and increase the natural frequency of the tubes reducing flow induced vibration.

Growing community of inventors

Cambridge, Canada

Jun Tang