Pool-Type Nuclear Reactor Removable Fuel Element Support

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional pool-type nuclear reactors face challenges with non-replaceable core-supporting grids, complex refueling processes, and increased reactor size due to shielding and neutron flow concerns, leading to reduced plant availability and increased dimensions.

Innovation Solution

A nuclear reactor design featuring a removable supporting system for fuel elements, where the core is supported by a structure that can be replaced and positioned in cold gas, eliminating the need for complex anchoring and shielding, allowing for direct installation of control instrumentation and reduced reactor height.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the core is supported by a fixed grid anchored to the tank bottom, then the core is mechanically stable, but the grid and internal structure become non-replaceable and require increased shielding

Engineering Contradiction:

Improvecore mechanical stabilityVSAvoidcomponent replaceability

Core Design Contradiction:

Stability of the object's compositionVSEase of repair

Solution Approach 1:

The core support system is divided into replaceable modules: the grid structure is separated from the tank bottom anchoring, and the internal structure is made into a detachable assembly. This segmentation allows individual components to be replaced independently without replacing the entire support system, resolving the contradiction between stability and replaceability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The support system transitions from a static fixed grid to a dynamic removable assembly. The grid can be detached and repositioned, and the internal structure can be removed and replaced, enabling maintenance and upgrades while maintaining operational stability when assembled.

Inventive Principle:

Principle #15Dynamics

2Stability of the object's composition

If fuel elements are equipped with coupling systems to prevent floating in heavy liquid metal, then mechanical stability is improved, but device complexity and handling difficulty increase

Engineering Contradiction:

Improvefuel element positional stabilityVSAvoidcoupling system complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The coupling function is merged into the grid structure itself rather than being a separate system on each fuel element. The grid provides both mechanical support and positioning functionality, eliminating the need for complex individual coupling systems on each fuel element while maintaining stability.

Inventive Principle:

Principle #5Merging (Combining)

3Object-affected harmful factors

If shielding structures are introduced between the peripheral core and internal structure, then neutron flow damage is reduced, but reactor size increases significantly

Engineering Contradiction:

Improveneutron flow damageVSAvoidreactor volume

Core Design Contradiction:

Object-affected harmful factorsVSVolume of stationary object

Solution Approach 1:

The shielding function is extracted from bulky structural shielding and implemented through selective shielding materials placed only where neutron flow damage is most critical. This targeted approach provides necessary protection while minimizing the volume increase of the reactor.

Inventive Principle:

Principle #2Taking out (Extraction)

4Reliability

If refueling machines operate within a closed high-temperature primary system, then safety is improved, but mechanism blockage risk and operational complexity increase

Engineering Contradiction:

Improverefueling safetyVSAvoidrefueling operation ease

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

A primary circuit penetrator serves as an intermediary mechanism that allows refueling operations to occur while maintaining the integrity of the closed primary system. The penetrator enables fuel element handling within the high-temperature environment without direct exposure, reducing blockage risks while preserving safety.

Inventive Principle:

Principle #24Intermediary (Mediator)

5Object-affected harmful factors

If fuel elements extend underneath the active part to reduce grid damage, then grid protection is improved, but reactor height and fuel element length increase

Engineering Contradiction:

Improvegrid neutron damageVSAvoidreactor height

Core Design Contradiction:

Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

The grid structure is designed as a replaceable component with extended life through replacement rather than indefinite protection. This allows the fuel elements to have standard lengths without excessive extension, as the grid can be replaced periodically rather than requiring permanent protective extensions on all fuel elements.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS8817942B2Nuclear reactor, in particular pool-type nuclear reactor, with new-concept fuel elements

Publication Date: 2014.08.26 NEWCLEO SA

AI summary

The present invention relates to a nuclear reactor, in particular a pool-type nuclear reactor cooled with liquid metal (for example, a heavy metal such as lead or lead-bismuth eutectic) or with sodium or molten salts, having a core formed by a bundle of fuel elements and immersed in a primary fluid circulating between the core and at least one heat exchanger; the fuel elements extend along respective parallel longitudinal axes and have respective bottom active parts immersed in the primary fluid to constitute the core, and respective service parts that extend at the top from the active parts and emerge from the primary fluid; the fuel elements are mechanically supported via respective top end heads anchored to supporting structures and can be operated via handling machines.