The pump assemblies used in nuclear power plant applications need to be evaluated for design parameters as well as seismic qualifications in order to ensure their reliability considering the criticality of their applications. The design guidelines for these components are provided in subsections NB, NC, ND & NF of ASME BPVC Sec. III. These sections are described based on the criticality of the components with NB subsection having guidelines for most critical components as likewise the other subsections with reduced criticality. The design is evaluated for various loading combinations described as Level-A through Level-D. This loading also includes seismic loading which corresponds to seismic response at the pump installation site.
Renowned Pump Manufacturer from India approached ANALYZER to seek assistance in evaluating the design of their newly developed pump assembly for its reliability being a nuclear power plant product.
The FEA model is prepared for complete pump assembly. In order to avoid complexities, bearings & coupling is modeled in a much simpler way in FEA. The first model is solved in order to extract the foundation loading & complete assembly is solved for various load combinations.
The results showed that the foundation loads are much below the allowable limits. The stresses for various load combinations are within the allowable limit. The assembly is also evaluated for close clearances between mating parts & is predicted to be working fine under severe operating conditions also. Thus the pump design was predicted to be safe even in severe operating conditions during its service life.