Nuclear-Powered Vacuum Microelectronics for In-Core Reactor Sensing

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Solution Overview

Problem

Conventional power sources, such as chemical batteries and thermoelectric generators, cannot survive the harsh environment of a nuclear reactor core, making it difficult to power wireless transmission of in-core detector signals from nuclear reactors, which requires a reliable and self-sustaining power source within the reactor vessel.

Innovation Solution

A solid state vacuum micro-electronic device with a fissionable heater element, using fissile material like uranium dioxide, to generate thermal energy for powering the device, combined with a self-powered neutron flux detector to establish a voltage bias, enabling the operation of a wireless transmitter within the reactor core.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional power sources (chemical batteries, thermoelectric generators) are used in the reactor core, then the device can be powered initially, but the power source cannot survive the harsh in-core environment over long durations

Engineering Contradiction:
Improvepower source survival in reactor environmentVSAvoidoperational lifetime of power source
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent changes the energy generation mechanism from chemical reactions (batteries) or thermoelectric conversion to nuclear fission. The heater element contains fissile material that undergoes nuclear fission, fundamentally changing the energy source parameter to achieve both high temperature operation and extended lifetime in the reactor core environment.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a replaceable heater element containing a small amount of fissile material (e.g., 0.1 to 1 gram of U-235 or Pu-239). This disposable component can be replaced after a defined operational period, allowing the expensive vacuum microelectronic device to be reused while the consumable heater element absorbs the environmental degradation.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Power

If a heater circuit is used to power the cathode, then electron emission can be achieved, but conventional power supplies cannot provide sufficient energy for long-duration operation in the reactor core

Engineering Contradiction:
Improvepower output for cathode heatingVSAvoidoperational duration of power supply
Core Design Contradiction:
PowerVSDuration of action of stationary object

Solution Approach 1:

The patent changes the power generation parameter from chemical energy density to nuclear energy density. The fissionable material in the heater element provides sustained thermal power output that can maintain cathode heating for extended periods in the reactor core, overcoming the limited energy capacity of chemical batteries.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If reactor vessel penetrations are increased for cabling, then in-core instrumentation can be powered and controlled, but the risk of coolant leakage increases

Engineering Contradiction:
Improveinstrumentation control capabilityVSAvoidcoolant leakage risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the power generation function from external reactor systems and places it within the vacuum microelectronic device itself via the fissionable heater element. This self-powered approach eliminates the need for external power cabling through reactor vessel penetrations, thereby removing the associated coolant leakage risk while maintaining full instrumentation control capability.

Inventive Principle:
Principle #2Taking out (Extraction)

4Object-affected harmful factors

If wireless transmission is implemented for in-core detector signals, then the number of reactor vessel penetrations is reduced, but a self-sustaining power source is required within the reactor vessel

Engineering Contradiction:
Improvereactor vessel penetration countVSAvoidpower source integration complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the power generation function with the vacuum microelectronic device by integrating the fissionable heater element directly into the device structure. This combination provides the self-sustaining power source needed for wireless transmission while keeping the overall system compact and suitable for placement within the reactor core.

Inventive Principle:
Principle #5Merging (Combining)

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

This solution provides a reliable and long-lasting power source for in-core electronics, reducing the need for reactor vessel penetrations and ensuring safe and efficient wireless transmission of detector signals from the reactor core.

Implementation Method 1

the heater comprises fissile material

Methodology Applied
Scientific EffectNuclear fission: Nuclear Fission

Implementation Method 2

The cathode emits electrons when the heater circuit reaches the appropriate thermal energy

Methodology Applied
Scientific EffectThermionic emission: Thermionic Emission

Data Source

PatentEP3619723B1Nuclear powered vacuum microelectronic device
Publication Date: 2023.03.08 WESTINGHOUSE ELECTRIC CORP
  • EP3619723B1 patent drawingFigure 1~2
  • EP3619723B1 patent drawingFigure 3~4
  • EP3619723B1 patent drawingFigure 5

AI summary

A vacuum micro-electronics device that utilizes fissile material capable of using the existing neutron leakage from the fuel assemblies of a nuclear reactor to produce thermal energy to power the heater/cathode element of the vacuum micro-electronics device and a self-powered detector emitter to produce the voltage/current necessary to power the anode/plate terminal of the vacuum micro-electronics device.