Abstract: Segmented stayrod for restricting transverse displacement of a nuclear heat exchanger tube support plate. The stayrod includes a first rod segment interposed between the tubesheet and the first support plate, the first rod segment having an externally threaded riser extending through the hole formed in the first support plate. The stayrod also has a second rod segment interposed between the first support plate and the second support plate, the second rod segment having an internally threaded end portion for threadably engaging the threaded riser of the first rod segment. The second rod segment also has an externally threaded riser extending through the hole formed in the second support plate. An internally threaded fastener threadably engages the riser of the second rod segment for fastening the second rod segment to the second support plate. In this manner, the first support plate is captured between the first rod segment and the second rod segment.

Abstract: Device and method for thermally insulating a structure to prevent thermal shock therein, which structure may be a feedwater inlet nozzle of the kind typically found on nuclear steam generators. The device comprises a sleeve extending into the bore of the nozzle for thermally insulating the nozzle and joined to the nozzle to affix the sleeve to the nozzle. The sleeve is so joined to the nozzle so as to define a joint therebetween. A liner is concentrically disposed in the sleeve so as to cover the joint to thermally insulate the joint and joined to the sleeve for affixing the liner to the sleeve. The nozzle may have a temperature significantly higher than the cooler feedwater flowing through the bore in the nozzle thereby giving rise to a potential for thermal shock in the nozzle, which thermal shock in turn may induce metal fatigue in the nozzle. The device, as it is disposed in the bore of the nozzle, thermally insulates the nozzle to prevent thermal shock and metal fatigue therein.

Abstract: This patent discloses a secondary fluid supply system for a steam generator used in nuclear reactor power plants. The secondary fluid supply system comprises a secondary fluid (feedwater) inlet nozzle near the base of the steam generator shell, a feedwater riser pipe spaced between the shell of the steam generator and the tube bundle wrapper, the upper end of the feedwater riser pipe being connected to a distribution ring having a plurality of spray nozzles positioned in the recirculating pool above the top of the U-shaped heat exchanger tubes.