I-shaped reactor external melt retention device used after nuclear power plant accident

The invention relates to a V-shaped reactor external melt retention device used after a nuclear power plant accident. The V-shaped reactor external melt retention device comprises an inner wall, a steam channel wall fixed at an opening in the bottom of the inner side of the inner wall, a pressure container arranged in the steam channel wall, an outer wall surrounding the inner wall, a reactor core melt retention device fixed at the bottom of the inner wall and a reactor core melt cooling device which is in tight contact with the bottom of the reactor core melt retention device, wherein a coolant descending channel is formed between the inner wall and the outer wall; a coolant channel is formed between the inner wall and the reactor core melt retention device; a reactor core melt retention groove is formed in the upper surface of the reactor core melt retention device under the pressure container; the lower surface of the reactor core melt retention device is a plane; the reactor core melt retention device is made of an inorganic non-metal fireproof material. By adopting a melt retention design outside a reactor, melts are accommodated by different materials and are cooled by a coolant loop and the reactor core melt cooling device, and therefore, the safety of a nuclear power plant.