10 results about "MOX fuel" patented technology

The invention belongs to the technical field of nuclear fuel detection, and particularly relates to an X-ray detection device for MOX fuel assembly welding seams. The device comprises a control system, an X-ray shielding chamber, an imaging detection system and an X-ray emission system, the control system is arranged outside the X-ray shielding chamber and is connected with the imaging detection system and the X-ray emission system so as to control the imaging detection system and the X-ray emission system; the imaging detection system and the X-ray emission system are arranged in the X-ray shielding chamber and used for conducting X-ray detection on the MOX fuel assembly welding seam. The X-ray digital imaging high-sensitivity on-line automatic detection of the MOX fuel assembly weld defect is realized, the blank in the prior art is filled, and the X-ray digital imaging high-sensitivity on-line automatic detection device is ingenious in design, convenient to use and suitable for being applied to the on-line X-ray digital imaging high-sensitivity detection of the MOX fuel assembly weld defect.

The present application relates to a kind of preparation methods of pressurized water reactor MOX fuel powder, comprising the following steps: by mixed actinide salt and urea solid preparation mixed actinide eutectic, mixed actinide eutectic is directly obtained by deamination, denitrogenation / decarbonation, reduction, MOX fuel powder;The mixed actinide salt is hexavalent actinide nitrate and tetravalent actinide oxalate;When the mixed actinide salt is uranyl nitrate hexahydrate solid and thorium oxalate hexahydrate solid, the MOX fuel powder is (U x Th 1‑x )O2;When the mixed actinide salt is uranyl nitrate hexahydrate solid and plutonium oxalate hexahydrate solid, the MOX fuel powder is (U x Pu 1‑x )O2.The method provided by the present application has simple raw materials, can greatly simplify the preparation process of MOX fuel powder composed of UO2 and PuO2 (or ThO2), reduce the use of process reagent, and does not produce any process waste liquid, thereby providing a simple, high production efficiency, waste liquid-free, more economical and green MOX fuel powder preparation method.

Provided in the embodiments of the present application is a preparation method for an MOX fuel powder. An MOX fuel powder comprises a plurality of actinide nuclide oxides. The method comprises the following steps: S1, mixing different actinide nuclide salts with urea to form a mixed actinide eutectic system, the actinide nuclide salts being one of hexavalent actinide nitrates, tetravalent actinide nitrates, hexavalent actinide oxalates and tetravalent actinide oxalates; S2, heating the mixed actinide eutectic system obtained in step S1 to a first preset temperature for performing deamination treatment on the mixed actinide eutectic system, so as to remove the urea therein; and S3, heating the product obtained after the deamination treatment in step S2 to a second preset temperature for performing denitrification and / or decarburization treatment on the product obtained in step S2, so as to obtain a plurality of actinide nuclide oxides. Provided in the embodiments of the present application is the preparation method for an MOX fuel powder, which is simple, does not produce a waste liquid, is more economical and environmentally friendly, and can obtain a completely uniform MOX fuel powder.

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.

The application discloses a configuration method of uranium-plutonium mixed fuel for a pressurized water reactor, comprising the following steps: S1, calculating the equivalent share difference D of a target raw material; S2, calculating the equivalent life coefficient C of an existing raw material; S3, determining the uranium-plutonium mixed ratio of the existing raw material; and S4, taking the existing raw material and uranium raw material, mixing and configuring to obtain the uranium-plutonium mixed fuel for the pressurized water reactor according to the uranium-plutonium mixed ratio of the existing raw material. The application further discloses the uranium-plutonium mixed fuel for the pressurized water reactor configured by using the configuration method. The application can utilize the existing raw material in a spent fuel reprocessing plant, configure the MOX fuel with the same core life length compared with the MOX fuel configured by the target raw material without changing the plutonium isotope composition, break the limitation of raw material selection in the prior art, and fully utilize the existing raw material in the spent fuel reprocessing plant.

The application discloses a MOX fuel rod helium pressurizing device, which comprises a container, a glove box and a vacuum pump, the container is communicated with the glove box, a quick opening cover is arranged at the communication position of the container and the glove box, a feeding port is arranged on the glove box, a sealing door is arranged on the feeding port, a MOX fuel rod is fed into or out of the glove box through the feeding port, an air inlet and a first exhaust port are arranged on the container, the vacuum pump is connected with the first exhaust port and used for vacuumizing the container, an air inlet valve is arranged on the air inlet, and the air inlet is used for feeding in helium. The MOX fuel can be subjected to the helium pressurizing operation, so that the situation that the helium in the fuel rod is completely leaked and cannot be detected is avoided, and the accuracy of helium leakage detection is ensured.

The present application relates to the technical field of MOX fuel production, and particularly discloses a MOX simulation powder forming and pressing method for forming and pressing the granulated powder, which comprises the following steps: step one: adjusting the forming and pressing parameters according to the granularity of the granulated powder; step two: filling the granulated powder into a pressing mold to obtain a green body through forming and pressing; step three: the green body after completing the pressing enters a demolding procedure; and step four: after the demolding is completed, the appearance, density and strength of the green body are detected according to the technical conditions of the MOX simulation green body, and whether the green body meets the requirements is detected. The method can effectively improve the forming and pressing effect and improve the qualified rate of the green body.

The invention belongs to the technical field of nuclear reactors, and particularly relates to a reactor first cycle passive starting method based on MOX fuel assemblies. Comprising the following steps: step 1, after reactor charging is started, firstly, MOX fuel assemblies are arranged at the periphery of a reactor core in a position close to an out-of-reactor high-sensitivity detector according to a certain sequence; 2, sequentially loading the reactor core fuel assemblies according to a diagonal snakelike mode; and 3, for a reactor core scheme that the MOX fuel assemblies are loaded in a reactor core inner area, moving the reactor core positions A08, R08, H01 and H15 of the MOX fuel assemblies loaded near the high-sensitivity detector in the step 1 to the reactor core positions C08, N08, H03 and H13 of the MOX fuel assemblies in the reactor core scheme, and then loading the fuel assemblies determined in the reactor core scheme at the positions near the high-sensitivity detector in the step 1. The method has the beneficial effects that non-blind-area passive starting of the first-cycle reactor can be realized by loading the MOX fuel assembly in the first-cycle reactor core and arranging the out-of-reactor high-sensitivity detector.

The invention relates to a fuel intended to be irradiated in a fast-neutron nuclear reactor, comprising grains of at least one metal selected from U, Pu or Th, the grains being compressed in a volume, the fuel being porous, the fuel being characterised in that it comprises open intergranular pores forming an interconnected porosity, the porosity volume fraction preferably being between 3% and 30%, and more than 50% or 80% of the porosity being open intergranular porosity.

The invention belongs to the technical field of automatic detection, and particularly relates to a device for detecting welding seam defects on the outer surface of an MOX fuel assembly. The device comprises a stand column, a supporting seat, an inspection system, a shielding body and a supporting seat, the stand column, the supporting base, the inspection system and the supporting base are all arranged in the shielding body. The stand column is vertically fixed to the supporting base. The supporting seat is movably fixed on the stand column and is used for fixing and supporting the MOX fuel assembly; the inspection system is located on the supporting base and used for detecting the outer surface of the MOX fuel assembly. According to the invention, the overall dimension of the MOX fuel assembly and the weld surface defects can be rapidly and accurately measured and finely identified, the outer surface of the assembly can be deeply identified, the method has the advantages of high automation degree, no need of manual close-range operation and the like, and the risk that personnel are irradiated is reduced at the same time.