Liquid Fuel Nuclear Reactor Self-Replenishing Fissile Diffusion

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Solution Overview

Problem

Current nuclear fission reactors face challenges in efficiently replenishing fissile fuel materials consumed during fission, as existing methods do not effectively utilize the transmutation of fertile fuel materials into fissile fuel within the reactor environment.

Innovation Solution

A nuclear fission reactor design where fissile nuclear fission fuel is dissolved in a neutronically translucent liquid carrier material, with undissolved fertile fuel in contact, allowing transmutation and diffusion of fissile fuel to replenish the fissile fuel supply, utilizing materials like Mg as a carrier and 238U as fertile fuel, enhancing diffusion rates through specific surface area and concentration gradients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If fissile fuel is dissolved in liquid carrier material with undissolved fertile fuel in contact, then fissile fuel can be replenished through transmutation and diffusion, but the system complexity increases compared to traditional solid fuel elements

Engineering Contradiction:
Improvefuel replenishment rateVSAvoidfuel system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system enables self-replenishment of fissile fuel through the diffusion mechanism. The undissolved fertile fuel material automatically transmutes into fissile fuel and diffuses into the liquid carrier, creating a self-sustaining fuel cycle without requiring external intervention for fuel replacement.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the physical state of the fuel from solid to dissolved/undissolved mixture in liquid carrier. This parameter change enables dynamic fuel composition adjustment through diffusion, allowing the system to adapt fuel concentration and distribution based on operational conditions.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If diffusion rates are enhanced through increased surface area and concentration gradients, then fissile fuel replenishment efficiency improves, but the manufacturing precision requirements for fuel pin structure increase

Engineering Contradiction:
Improvefuel diffusion rateVSAvoidfuel pin structure precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The fuel pin structure incorporates porous or high-surface-area materials to enhance the interface between dissolved and undissolved fuel phases. This increases the effective surface area for diffusion and transmutation reactions, improving fuel replenishment efficiency without requiring extreme manufacturing precision.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention transitions from traditional one-dimensional fuel rod structures to a three-dimensional liquid-filled configuration where fuel material can move and distribute in multiple directions. This dimensional change enables enhanced diffusion pathways and surface area utilization.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If fertile fuel material is used to transmute into fissile fuel, then fuel efficiency improves, but the loss of fertile material through transmutation reduces the quantity of available fuel

Engineering Contradiction:
Improvefuel efficiencyVSAvoidfertile fuel quantity
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The system recovers fissile fuel in-situ from the transmutation of fertile fuel material. Instead of discarding fertile material after use, the system continuously converts it into fissile fuel through neutron capture and diffusion, effectively recovering and reusing the fuel potential.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The system performs preliminary transmutation of fertile fuel into fissile fuel before the fissile fuel is completely consumed. This advance conversion ensures a continuous supply of fissile material is available, preventing fuel depletion and maintaining reactor criticality.

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

This approach effectively replenishes fissile fuel within the reactor, improving fuel efficiency and maintaining a critical configuration by establishing a higher concentration gradient, thereby sustaining reactor operation.

Implementation Method 1

diffusion rates through specific surface area and concentration gradients

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

transmutation of fertile fuel materials into fissile fuel within the reactor environment

Methodology Applied
Scientific EffectNuclear transmutation: Nuclear Fission

Data Source

PatentEP2577677B1Liquid fuel nuclear fission reactor
Publication Date: 2019.08.21 TERRAPOWER LLC
  • EP2577677B1 patent drawingFigure 1A
  • EP2577677B1 patent drawingFigure 1B
  • EP2577677B1 patent drawingFigure 1C

AI summary

Disclosed embodiments include nuclear fission reactors, nuclear fission fuel pins, methods of operating a nuclear fission reactor, methods of fueling a nuclear fission reactor, and methods of fabricating a nuclear fission fuel pin.