The utility model provides an integration that contains poisonous substance jar is piled, including the pressure thimble body, the internal lower part of pressure thimble is provided with the poisonous substance jar, and the poisonous substance jar includes poisonous substance jar inner shell and poisonous substance jar shell, forms the last boron water cavity that is used for holding boron waterbetween poisonous substance jar inner shell and the poisonous substance jar shell, upward is provided with the active reactor shutdown system of non - on the poisonous substance jar above the boron water cavity, the middle reactor core that is provided with bottom the poisonous substance jar is inside, and poisonous substance jar outside is provided with steam generator, and the internal portion of pressure thimble is provided with drive arrangement, the internal cavity that is provided with of pressure thimble of steam generator top is gone up the cavity and with poisonous substance jar and steam generator intercommunication, is formed annular descending channel between the poisonous substance jar and the pressure thimble body, and the circumference side of the lower extreme of reactor core is opened there is radial cooling agent runner, and the cooling agent runner is with descending channel and reactor core intercommunication. The utility model discloses cancelled the control rod intraditional PWR, one kind and install the poisonous substance jar inside in pressure vessel heap type.