Steam generator design for ACR-1000

Babcock and Wilcox Canada (BWC) has developed a preliminary design for an advanced recirculating steam generator (RSG) to meet the Atomic Energy of Canada Limited (AECL) design requirements for the Advanced CANDU reactor (ACR-1000) steam generators. In addition to fulfilling all thermal hydraulic requirements, the ACR-1000 advanced RSGs offer improved reliability by addressing all degradation problems known within the industry. The ACR-1000 RSG design builds upon BWC's long history of steam generator design and manufacturing experience which includes 247 steam generators for CANDU nuclear systems and 42 replacement steam generators for US PWR nuclear power plants. The ACR-1000 RSG features an optimized Alloy 800 tube bundle that satisfies all heat transfer requirements with plugging and fouling margin and is arranged within the pressure boundary such that flow resistances are minimized. Taking advantage of BWC's exceptional performance history with integral preheaters, the ACR-1000 RSG will have an advanced preheater to minimize tube bundle size and cost. Lattice grid tube supports and flat bar U-bend restraints provide effective structural support for the tube bundle and prevent damaging flow induced vibration. The overall tube bundle arrangement maximizes secondary side circulation which benefits steam generator deposition, hydraulic stability and operating characteristics. Proven high efficiency steam separators, providing high quality steam to the turbines, are arranged within the steam drum such that all water level control requirements are satisfied. In-service inspection and maintenance is facilitated by carefully positioned access openings. The steam generator includes features to control tube bundle deposition. These features and advanced materials qualify the ACR-1000 RSGs for an extensive design life. (author)