Separation system of a new-generation boiling-water vessel reactor

Steam separation design is considered with respect to the construction of new BWRs in the Russian Federation. Two steam separator designs for simplified boiling water reactors (SBWRs) in nuclear power plants are briefly described. The effects of separation system and draft section construction on reactor vessel dimensions are investigated to determine the optimal design for an enhanced-safety BWR with natural coolant circulation. Three systems were examined: (1) free steam volume, secondary louvered separator, and common draft section; (2) submerged sheet with no-bubbling attachments, secondary louvered separator, and common draft section; and (3) submerged sheet with no-bubbling attachments (or on-axis centrifugal separators), additional steam volume, and draft pipe/mixing chamber draft section. The calculated reactor vessel inner diameter and height reactor corresponding to the three separation systems were determined to be: (1) 7m and 21.4m, (2) 6.7m and 17.75m, and (3) 6.7m and 14.25m. Separation designs (1) and (2) were examined for a 500 MW(e) reactor; design (3) was determined to be appropriate for unit power levels up to 300 MW(e). 9 refs., 3 figs.