Compact Medical Neutron Source with Start-Stop Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current neutron therapy devices for cancer treatment are complex, cumbersome, and costly, with high-enrichment fuel that limits their widespread use and requires extensive infrastructure, making them unsuitable for clinical settings and difficult to operate in a start-stop mode for precise tumor irradiation.
Innovation Solution
A small-sized, low-power nuclear reactor with a start-stop mode and minimal radioactive waste production, designed for direct clinical use, featuring a collimator, neutron filter, and movable gates to provide controlled neutron flux for neutron capture and fast neutron therapy, using uranium dioxide fuel with 15-20% enrichment and boron carbide control rods, and a coolant system for stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional neutron therapy devices are used, then neutron flux density is achieved, but device complexity and infrastructure requirements increase significantly
Solution Approach 1:
The device is divided into distinct functional modules: a compact nuclear reactor core, a separate collimator system with movable gates, and an independent neutron filter. This segmentation allows each component to be optimized independently and simplifies the overall system architecture, reducing infrastructure requirements while maintaining high neutron flux density for therapy.
Solution Approach 2:
The invention extracts only the essential neutron-generating function from complex conventional reactors, creating a simplified compact reactor design that produces neutron flux without requiring extensive support infrastructure. The collimator and filter systems are also designed as standalone components that can be independently adjusted.
2Productivity
If high-enrichment fuel is used, then neutron production efficiency is improved, but safety and proliferation risks worsen
Solution Approach 1:
The invention changes the enrichment parameter from conventional high-enrichment (typically >20% U-235) to a reduced enrichment level (10-20% U-235). This parameter change maintains sufficient neutron production efficiency for therapeutic applications while significantly reducing safety concerns and nuclear proliferation risks, allowing the reactor to operate safely in a clinical environment.
3Stability of the object's composition
If continuous operation mode is used, then neutron beam stability is improved, but ability to perform precise start-stop irradiation worsens
Solution Approach 1:
The collimator system incorporates movable gates that can dynamically adjust the neutron beam path, enabling precise start-stop irradiation of tumors. The reactor core design includes control elements that allow rapid power adjustment, maintaining neutron beam stability during operation while providing the operational flexibility to start and stop irradiation precisely when needed for therapeutic accuracy.
4Volume of moving object
If reactor size is reduced for clinical use, then ease of deployment is improved, but neutron flux intensity worsens
Solution Approach 1:
The reactor core employs composite fuel elements combining uranium dioxide with specific moderators and reflectors in a optimized configuration. This composite structure maximizes neutron production efficiency within a compact volume, achieving sufficient neutron flux intensity for therapy despite the reduced reactor size required for clinical deployment.
Solution Approach 2:
The neutron flux is concentrated locally at the treatment position through the collimator system and movable gates, which focus the neutron beam precisely on the tumor target. This local concentration of neutron quality compensates for the reduced overall reactor size, delivering intense neutron flux exactly where needed for effective therapy.
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 solution provides a safe, cost-effective, and reliable neutron source for cancer therapy, capable of maintaining the required neutron flux density for therapeutic sessions with minimal radioactive waste and operational complexity, ensuring precise tumor irradiation while minimizing harm to healthy tissue.
Implementation Method 1
nuclear reactor with a core in the form of a parallelepiped... using uranium dioxide fuel with 15-20% enrichment
Implementation Method 2
collimator, neutron filter, and movable gates to provide controlled neutron flux for neutron capture and fast neutron therapy
Implementation Method 3
The required spectrum of epithermal neutrons can be formed behind a filter several dozen centimeters thick
Implementation Method 4
a coolant system for stable operation
Data Source
AI summary
A coolant having a set temperature is fed into the nuclear reactor core of a medical neutron source, which is in a subcritical state. The nuclear reactor core is transitioned from the subcritical state to a critical state until the nominal power of the nuclear reactor is achieved. A neutron output channel is opened in order to conduct a neutron therapy session, and the operation of the reactor is maintained at nominal power while the neutron therapy session is conducted. At the end of the session, the neutron output channel is closed at the same time as the reactor core is transitioned to a subcritical state. The temperature of the coolant entering the core is maintained unchanged and equal to a set temperature, both when the core is transitioned to a critical state and during the operation of the nuclear reactor at nominal power.