Part-load operation of the boiler feedwater pumps for the new French PWR 1400 MW nuclear plants - a challenge for the designer

The Boiler feedwater pumps in Electricite de France Power Stations have to work reliably for all flow rates between 33% and 134% of the flow corresponding to the best efficiency point (QBEP). Under transient conditions associated with load changing these limits increase to 33% to 147% QBEP. Due to the high specific power of these pumps, the operating conditions heavily influence the hydraulic and mechanical dimensioning. This paper presents some particular aspects of their design and test results obtained on a pump model as well as on a full scale prototype concerning suction performance, head capacity curve stability, pressure pulsations and structural excitations. (author)