Reactor Pressure Vessel Cutting Rails for Faster Nuclear Decommissioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for decommissioning a nuclear facility, particularly the pressurized water reactor type, require excessive working time due to the complexity of cutting and separating the nuclear reactor pressure vessel from the bio-protective concrete.
Innovation Solution
A method involving a cutting device with a first rail and a second rail system, along with a fixture, allows for the stable cutting and decommissioning of the nuclear reactor pressure vessel by enabling the cutter to move circumferentially and vertically within the cavity, while the vessel is fixed in place, reducing the overall working time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional cutting methods are used to separate the nuclear reactor pressure vessel from the bio-protective concrete, then the cutting and decommissioning process can be completed, but the working time required is excessive
Solution Approach 1:
The decommissioning process is divided into distinct segments: first cutting and expanding the inner wall of the cavity, then installing the cutting device, fixing the pressure vessel, and finally cutting the vessel. This segmentation allows each step to be optimized independently and performed systematically, improving overall decommissioning efficiency
Solution Approach 2:
The inner wall of the cavity is cut and expanded in advance before the cutting device is installed. The pressure vessel is fixed to the inner wall using fixtures before the actual cutting of the vessel begins. These preliminary actions prepare the workspace and secure the workpiece, enabling the subsequent cutting operation to proceed efficiently without interruptions
2Reliability
If the nuclear reactor pressure vessel is not fixed during cutting, then the cutting device can access the vessel more easily, but the cutting process becomes unstable and less precise
Solution Approach 1:
Fixtures serve as intermediary components between the inner wall of the cavity and the nuclear reactor pressure vessel. These fixtures provide a stable connection that secures the vessel during cutting operations, ensuring cutting stability and precision without requiring direct complex attachment mechanisms between the cutting device and the vessel
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 enables efficient and stable cutting and decommissioning of the nuclear reactor pressure vessel, reducing the time required for the process and improving work efficiency by allowing simultaneous cutting of upper and lower portions.
Implementation Method 1
The driver may include: a rack gear installed in the first rail; a pinion gear installed in the second rail and engaged with the rack gear; and a driving motor providing a driving force to the pinion gear.
Implementation Method 2
The variable rod may include: a first rod provided with one end supported in contact with the inner wall surface of the cavity; a second rod provided with one end supported in contact with the surface of the nuclear reactor pressure vessel; and a rotating rod that is provided with one side screwed to the first rod and the other side screwed to the second rod and that makes the first rod and the second rod come close to each other or separates them from each other.
Data Source
AI summary
A method for complex-decommissioning a nuclear facility is disclosed. The method for complex-decommissioning the nuclear facility includes: cutting and expanding an inner wall of the cavity; installing a cutting device that cuts and decommissions the nuclear reactor pressure vessel inside the cavity; fixing the nuclear reactor pressure vessel inside the cavity by using a fixture; and cutting and decommissioning the nuclear reactor pressure vessel fixed inside the cavity by using a cutting device.