Boron-11 SiC Material for Nuclear Reactor Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional silicon carbide (SiC) fibers used in nuclear applications are unsuitable due to the boron-10 isotope in sintering aids, which undergoes fission and causes outgassing and degradation when irradiated, making them unstable for nuclear reactor components.
Innovation Solution
A precursor formulation of SiC material incorporating boron-11 isotope as a sintering aid, which is stable under irradiation and does not undergo fission, allowing for the production of SiC fibers or bodies suitable for nuclear applications without outgassing or degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If boron-10 isotope is used as sintering aid in SiC fibers, then densification and fine grain size are improved, but stability under nuclear irradiation deteriorates due to fission and outgassing
Solution Approach 1:
The patent changes the isotopic parameter of boron from the conventional boron-10 to boron-11. This parameter change maintains the sintering aid functionality while eliminating the harmful fission reaction under neutron irradiation, thus resolving the contradiction between manufacturing precision and reliability in nuclear applications
Solution Approach 2:
The patent converts the harmful effect of boron-10 (which undergoes fission and causes degradation) into a beneficial solution by using boron-11, which is stable under irradiation. The boron compound still serves as an effective sintering aid but without the harmful fission byproducts, transforming a harmful material into a beneficial one for nuclear applications
2Strength
If conventional SiC fibers are used in nuclear reactor components, then mechanical strength at high temperatures is achieved, but degradation and outgassing occur when exposed to nuclear radiation
Solution Approach 1:
The patent changes the isotopic composition parameter of the boron compound from boron-10 to boron-11. This parameter change preserves the mechanical strength and high-temperature properties of SiC fibers while eliminating the degradation and outgassing issues that occur under nuclear radiation
Solution Approach 2:
The patent replaces the unstable boron-10 containing material with stable boron-11 containing material. While boron-11 may be less readily available, it provides long-term stability and durability in nuclear environments, effectively replacing a short-lived unstable material with a long-lived stable material
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The SiC material with boron-11 isotope maintains mechanical strength and resistance to high temperatures, preventing degradation and outgassing when exposed to nuclear radiation, making it suitable for use in nuclear reactor components like control rods and fuel cladding.
Implementation Method 1
The ceramic fibers are heated in the presence of a sintering aid to produce the polycrystalline SiC fibers. The sintering aid is boron or a boron-containing compound, such as a boron oxide (B2O3).
Implementation Method 2
11B is the most commercially available isotope because 10B is more easily extracted from ore than 11B. 10B absorbs neutrons and is used in control rods of nuclear reactors, as a shield against nuclear radiation, and in instruments for detecting neutrons. However, 10B is unstable and undergoes fission when irradiated, producing a gamma ray, an alpha particle, and a lithium ion. Therefore, when a component formed from conventional SiC fibers is irradiated, the boron compound undergoes fission, which is accompanied by outgassing and degradation of the SiC fibers or the SiC bodies.
Data Source
AI summary
A precursor formulation of a silicon carbide material that includes a ceramic material and a boron-11 compound. The ceramic material may include silicon and carbon and, optionally, oxygen, nitrogen, titanium, zirconium, aluminum, or mixtures thereof. The boron-11 compound may be a boron-11 isotope of boron oxide, boron hydride, boron hydroxide, boron carbide, boron nitride, boron trichloride, boron trifluoride, boron metal, or mixtures thereof. A material for use in a nuclear reactor component is also disclosed, as are such components, as well as a method of producing the material.