4 results about "Neutron poison" patented technology

The application discloses an off-site transportation container for plutonium dioxide powder product cups, which comprises an outer container, a shock absorber, an inner container and a holder, the inner container is arranged in the outer container, the shock absorber is arranged between the inner wall of the outer container and the outer wall of the inner container, and the holder is arranged in the inner container, the inner wall of the body of the outer container is filled with heat insulation material, the shock absorber is used for buffering the vibration of the inner container, the inner wall of the body of the inner container is filled with a shielding neutron poison, and the holder is used for supporting and limiting a plutonium dioxide powder product cup hanger. The technical scheme of the application can effectively reduce the influence of vibration and thermal shock in the transportation process on the plutonium dioxide powder product cups in the container, the shock absorption performance and the heat insulation effect are good, the product transportation requirements are met, and the safe transportation of radioactive substances is ensured.

The application discloses an evaporator and a PUREX process system, which comprises a heating chamber and a separation chamber, the heating chamber is an annular gap heating chamber, a feed liquid inlet and a concentrated liquid outlet are arranged on the annular gap heating chamber, a heating piece is arranged outside the heating chamber, and a hollow part is filled with a neutron poison; the bottom of the separation chamber is communicated with the top of the heating chamber, the top of the separation chamber is provided with a secondary steam outlet, and a leaching liquid inlet is further arranged on the separation chamber. The evaporator has the advantages of simple structure, large capacity, long discharge interval, low operation frequency, high purification efficiency, satisfaction of critical safety, very stable operation, realization of evaporation and concentration of plutonium-containing liquid, recovery of plutonium in a reprocessing plant and reduction of plutonium loss.

The invention relates to a boron-containing extraction agent, a preparation method thereof and application of the boron-containing extraction agent in critical plutonium purification prevention, and the boron-containing extraction agent is 2, 4, 6-trimethylphenoxy-bis [2-(N, N-dioctyl acetamide)] borate. According to the method, 2, 4, 6-trimethylphenol and bis [2-(N, N-dioctyl acetamide)] boric acid are used as raw materials, and the boron-containing extraction agent is prepared through a dehydration condensation reaction between phenolic hydroxyl groups and boric acid. The neutron poison B element is introduced into the amide extraction agent to obtain the anti-criticality boron-containing extraction agent; trimethylphenoxy is introduced to a central boron atom of the boron-containing extraction agent, and the boron atom with electron deficiency in the center is protected by utilizing a hyperconjugation effect and steric hindrance, so that the water stability of the boron-containing extraction agent is improved. The boron-containing extraction agent has a high-selectivity extraction effect on plutonium, and the extraction distribution ratio of uranium, americium, strontium, cesium and other fissure elements is very low; the method is suitable for separation, purification and recovery of a large amount of plutonium in a post-treatment plant and an MOX fuel preparation plant so as to eliminate the critical risk of organic phase extraction of plutonium.

A nuclear fission reactor comprising a passive thermal shut-down device, and a reactor core containing fissile fuel. The passive thermal shutdown device comprises a reservoir and a Pythagorean syphon. The reservoir is in thermal communication with the reactor core, and containing a neutron poison material which has a free surface. The Pythagorean syphon has an inlet within the reservoir, an outlet in fluid communication with the reactor core. When the neutron poison material overtops the syphon due to thermal expansion, the neutron poison material flows through the Pythagorean syphon and into the reactor core. Also provided are nuclear fission reactors having passive thermal shutdown devices using a Pythagorean syphon to control the flow of fissile fuel, neutron moderators, or neutron reflectors.