Full-ceramic fuel rod

Abstract

The invention discloses a full-ceramic fuel rod which comprises a cladding, an FCM pellet is arranged on the lower section in the cladding, an air cavity is formed in the upper section in the cladding, and an air cavity spring is arranged in the air cavity; the inner diameter of the cladding ranges from 13.5 mm to 15 mm. TRISO particles are loaded in the FCM pellet, the core of each TRISO particle is a UN or UO2 particle, and a loose pyrolytic carbon layer with the thickness of 100 + / -10 [mu] m, an inner compact pyrolytic carbon layer with the thickness of 35 + / -5 [mu] m, a SiC layer with the thickness of 35 + / -5 [mu] m and an outer compact pyrolytic carbon layer with the thickness of 20 + / -5 [mu] m are sequentially wrapped from inside to outside; the diameter of the core is 800 + / -50 microns; the length of the air cavity ranges from 45 mm to 55 mm. The free height of the air cavity spring ranges from 67.5 mm to 72.5 mm, the outer diameter ranges from 8.8 mm to 9.2 mm, and the wire diameter ranges from 1.875 mm to 1.925 mm. The fuel rod provided by the invention improves the uranium loading capacity, and can be suitable for the operation environment of a light water reactor.

Description

technical field [0001] The invention relates to the field of design of nuclear fuel elements, in particular to the design scheme of all-ceramic fuel rods applied to nuclear reactors. Background technique [0002] After the Fukushima accident in Japan, the safety of nuclear reactors has become the focus of attention of all countries, and the accident-resistant fuel has also become a research hotspot of nuclear fuel in various countries. All-ceramic microencapsulation materials and ceramic material claddings have attracted extensive attention due to their outstanding mechanical properties, fission gas containment capacity, and high-temperature corrosion resistance. [0003] The active light water reactor fuel pellets are UO 2 Compared with full-ceramic microencapsulated fuel (FCM), ceramics have lower thermal conductivity, poor fission gas containment capacity, large temperature gradient, and easy cracking. But FCM pellets and UO 2 Compared with the pellets, the uranium loa...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is: the current all-ceramic fuel rods, due to the low uranium loading of FCM fuel pellets, do not meet the requirements for adapting to the operation of light water reactors, the present invention provides a kind of all-ceramic fuel rods to solve the above problems , is a fuel rod with accident-resistant characteristics. The invention increases the inner diameter of the fuel rod by optimizing the design of the fuel rod size, increases the uranium loading, satisfies the continuity of the chain reaction, and is applicable to the operation of light water reactors. surroundings

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