Nuclear power plant multi-reactor accident radioactive consequence evaluation method

The invention discloses a nuclear power plant multi-reactor accident radioactive consequence evaluation method. The method comprises the following steps: (1) sequencing reactors with accidents; (2) calculating a release source strength weight factor of each accident reactor; (3) performing superposition calculation to obtain an equivalent source coordinate and a source strength weight factor; (4)generating an initial release time sequence and a release time length sequence, calculating and obtaining an initial release time offset sequence, calculating and obtaining equivalent source release time length, splitting a calculation time period and each release source, and superposing on the same time origin to generate a release source item of the equivalent source; (5) performing superposition calculation to obtain the actual discharge height of the equivalent source; (6) establishing a rectangular plane coordinate system by taking the center coordinate of the equivalent source as an original point, and calculati