Nuclear Reactor Fuel Movement Optimization via Branch Search

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Solution Overview

Problem

Current systems for managing fuel assemblies in nuclear reactors, particularly in traveling wave reactors, lack the capability to model and optimize fuel movements in real-time and with high fidelity, leading to suboptimal fuel burnup and potential disruptions in reactor criticality.

Innovation Solution

A specialized computer system capable of modeling and simulating fuel movements within the reactor core, utilizing a branch search algorithm to determine optimal fuel shuffling strategies that maintain criticality and maximize fuel burnup while adhering to thermal-hydraulic limits, incorporating neutronics, thermal-hydraulic, kinetic, mechanical, safety, and economic parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional fuel management systems are used to pre-determine fuel movements for each fuel cycle, then the system complexity is reduced and ease of operation is improved, but the fuel burnup optimization and response to dynamic changes deteriorate

Engineering Contradiction:
Improvefuel movement planningVSAvoidfuel burnup efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system transitions from static pre-determined fuel movement plans to dynamic real-time optimization. The optimization module continuously adjusts fuel assembly movements based on current reactor state, power distribution, and burnup levels, enabling the system to adapt to dynamic changes while maintaining operational simplicity through automated control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements continuous feedback loops where reactor performance data, power distribution, and burnup metrics are monitored in real-time and fed back to the optimization module. This feedback mechanism enables the system to automatically adjust fuel movement strategies to maximize burnup efficiency while maintaining ease of operation through closed-loop control.

Inventive Principle:
Principle #23Feedback

2Productivity

If complex real-time modeling and optimization of fuel movements is implemented, then fuel burnup optimization and reactor performance are improved, but the device complexity and computational requirements increase

Engineering Contradiction:
Improvefuel burnup efficiencyVSAvoidmodeling and optimization system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The complex optimization problem is segmented into modular components: neutronics modeling, thermal-hydraulic analysis, burnup calculation, and movement optimization. Each module handles specific aspects of the problem independently, reducing overall system complexity while enabling comprehensive real-time optimization of fuel burnup efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system introduces an intelligent optimization module as an intermediary between reactor operation and fuel management decisions. This module integrates multiple physics models and optimization algorithms, managing the computational complexity internally while presenting simplified control interfaces and automated decision-making to operators.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If traditional fuel shuffling operations are performed without real-time modeling, then the ease of operation is maintained, but the reliability of maintaining criticality and thermal-hydraulic limits deteriorates

Engineering Contradiction:
Improvefuel shuffling operationVSAvoidcriticality and thermal-hydraulic constraint maintenance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Real-time monitoring of criticality parameters and thermal-hydraulic conditions provides continuous feedback to the optimization module. This feedback ensures that proposed fuel movements maintain reliability constraints by predicting and preventing violations of criticality margins and thermal-hydraulic limits before actual shuffling operations occur.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary simulation and validation of fuel movement scenarios before execution. By pre-evaluating the impact of proposed shuffling operations on criticality and thermal-hydraulic parameters, the system ensures reliability constraints are maintained while simplifying operator decision-making through pre-validated movement plans.

Inventive Principle:
Principle #10Preliminary action

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

Enables continuous optimization of fuel movements, ensuring efficient fuel burnup and stable reactor operation by predicting optimal fuel assembly moves and maintaining criticality within specified constraints, thereby improving reactor performance and extending fuel cycle lengths.

Implementation Method 1

a first model associated with a plurality of neutronics parameters... a second model associated with a plurality of thermal-hydraulic parameters

Methodology Applied
Scientific EffectNeutron transport:

Implementation Method 2

fuel assemblies contain fissionable fuel, which can be bred up and burned in-situ

Methodology Applied
Scientific EffectNuclear fission: Nuclear Fission

Implementation Method 3

a second model associated with a plurality of thermal-hydraulic parameters

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 4

a second model associated with a plurality of thermal-hydraulic parameters

Methodology Applied
Scientific EffectFluid flow: Convection

Implementation Method 5

fuel located outside of a burn region may be slowly bred up in a convergent-divergent shuffling operation where fresh fertile fuel assemblies are inserted into the core

Methodology Applied
Scientific EffectNuclear transmutation:

Data Source

PatentEP3586341B1Method for modeling a nuclear reactor
Publication Date: 2023.10.25 TERRAPOWER LLC
  • EP3586341B1 patent drawingFigure 1
  • EP3586341B1 patent drawingFigure 2A
  • EP3586341B1 patent drawingFigure 2B

AI summary

A system is provided that determines optimal movements of fuel assemblies in a nuclear reactor, such as a traveling wave reactor (TWR). Such a system may be capable of modeling core operations and fuel moves in parallel to determine optimal fuel cycle moves responsive to one or more constraints, including, but not limited to core criticality and location of a deflagration wave within an operating reactor core. According to one embodiment, the optimal solution may be determined using a branch search to simulate possible fuel moves.