Method for encapsulating CaO-Y2O3-Al2O3-SiO2 glass at port of SiCf/SiC core cladding tube

Abstract

The invention relates to a method for encapsulating CaO-Y2O3-Al2O3-SiO2 glass at a port of a SiCf / SiC core cladding tube. Part of raw materials which are low in reaction activity and low in nuclear irradiation decay rate and have no side effects on the nuclear reaction process are selected, and a glass brazing filler metal is prepared through a melting-water cooling method; by means of the SiCf / SiC matched thermal expansion coefficient, good wettability and low high-temperature viscosity, packaging / connection of the SiCf / SiC composite core cladding tube is achieved under the conditions that the temperature is lower than the applicable temperature (<=1450 DEG C) of domestic third-generation SiC fibers and no pressure exists. The SiCf / SiC core cladding tube is promoted to be applied to a nuclear reactor, nuclear radiation leakage accidents are prevented in advance, and the operation safety of the nuclear reactor is improved. The method has the beneficial effects that the raw materials selected by an encapsulating agent are low-activity elements, the nuclear radiation decay of the encapsulating agent is small, the encapsulating agent has no side effect on a nuclear reaction process, and the mechanical and airtight requirements of port encapsulation of the core cladding tube are met, so that nuclear radiation leakage in the cladding tube can be effectively prevented in a harsh service environment, and nuclear radiation leakage accidents are prevented in advance.

Description

technical field [0001] The invention belongs to nuclear energy nuclear fuel cladding tube packaging technology, and relates to a SiC f / SiC core cladding tube port CaO-Y 2 o 3 -Al 2 o 3 -SiO 2 Glass encapsulation methods, specifically SiC f / SiC core cladding tube port CaO-Y 2 o 3 -Al 2 o 3 -SiO 2 The glass encapsulant and its encapsulation method are mainly used for port encapsulation and connection of nuclear cladding tubes. Background technique [0002] In 2011, a nuclear accident occurred at the Fukushima nuclear power plant in Japan. This was due to the zirconium alloy nuclear fuel cladding, which had a major safety hazard in the event of a dehydration accident in the reactor: the zirconium alloy cladding was rapidly oxidized in a high-temperature water vapor environment above 900°C, and gradually lost its mechanical properties. Performance and damage, resulting in core exposure and melting; at 1000 ℃, zirconium-water / steam react violently, producing a large ...

AI Technical Summary

Problems solved by technology

[0002] In 2011, a nuclear accident occurred at the Fukushima nuclear power plant in Japan. This was due to the zirconium alloy nuclear fuel cladding, which had a major safety hazard in the event of a dehydration accident in the reactor: the zirconium alloy cladding was rapidly oxidized in a high-temperature water vapor environment above 900°C, and gradually lost its mechanical properties. performance and damage, resulting in core exposure and melting; at 1000 ° C, zirconium-water / steam react violently, producing a large amount of high-temperature combustible hydrogen and heat, resulting in severe hydrogen explosion and serious nuclear leakage accident

These service requirements greatly limit the packaging technologies that can be applied

So far, the commonly used packaging technology is difficult to meet the requirements of its mechanical properties and airtightness at the same time

Images