Sub-criticality Controller Using Water-Activated Borates

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Solution Overview

Problem

The challenge is to prevent inadvertent self-sustaining nuclear chain reactions in radioactive waste storage and geological repositories, which can lead to radiation release and other safety hazards, requiring effective sub-criticality control to manage nuclear criticality risks.

Innovation Solution

A sub-criticality controller using a metallic composition with a metal component and a borate component, which forms borates when contacted with water, providing a neutron-absorbing barrier to prevent criticality by forming compounds with low solubility in water, thereby maintaining proximity to radioactive materials and absorbing neutrons.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If water is present in the repository, then neutron absorption is enhanced, but criticality risk increases due to neutron moderation

Engineering Contradiction:

Improveneutron absorptionVSAvoidcriticality risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces borates as an intermediary substance that mediates between water and fissile materials. The borates absorb neutrons that would otherwise be moderated by water and induce criticality, thereby protecting the system from the harmful effect of water presence while maintaining neutron absorption capability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful effect of water (neutron moderation leading to criticality risk) into a beneficial outcome by using borates to absorb the moderated neutrons. The water's neutron-moderating property, which is normally harmful, becomes manageable through the intermediary borate layer that captures these neutrons before they can cause criticality

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If borates are introduced to absorb neutrons, then criticality is prevented, but solubility in water may reduce effectiveness

Engineering Contradiction:

Improvecriticality preventionVSAvoidborate solubility

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the physical and chemical parameters of borates by forming them into specific compounds with controlled solubility characteristics. By adjusting composition, particle size, and chemical form, the borates maintain low solubility in water while preserving their neutron absorption capability, ensuring long-term effectiveness

Inventive Principle:

Principle #35Parameter changes

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 effectively reduces the risk of nuclear criticality by forming borates that absorb neutrons, preventing chain reactions and ensuring safety in radioactive waste storage and disposal, even in the presence of water intrusion.

Implementation Method 1

The metallic composition forms borates from the borate component when the metallic composition contacts the water

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

borates that absorb neutrons, preventing chain reactions

Methodology Applied

Scientific EffectNeutron absorption: Absorption (physical)

Data Source

PatentUS12260966B2Method of protecting radioactive waste from reaching criticality by using a controller that when contacted by water provides borates that absorb neutrons

Publication Date: 2025.03.25 NATIONAL TECHNOLOGY & ENGINEERING SOLUTIONS OF SANDIA LLC

AI summary

A container holds radioactive material. A sub-criticality controller protects the radioactive material from reaching a criticality from contact with the water. The sub-criticality controller includes a metallic composition having at least one metal component and at least one borate component bonded to the at least one metal component. The metallic composition forms a new borate that absorbs neutrons when the metallic composition contacts water in the case of an incident.