Unlocking maintenance-architecting STEP for maintenance and realizing remountable magnet joints

Area of Science:

• Fusion energy research
• Tokamak engineering
• Robotics and automation

Background:

• The Spherical Tokamak for Energy Production (STEP) project aims to deliver fusion energy.
• A hybrid maintenance strategy is central to STEP's design, balancing immediate post-shutdown tasks with long-term refits.
• Existing technologies require significant advancement to meet STEP's unique scale and operational environment.

Purpose of the Study:

• To outline the maintenance strategy for the STEP fusion energy project.
• To highlight the critical role of remountable magnet joints in the STEP maintenance plan.
• To detail the technology development programs addressing the risks and challenges of STEP's maintenance approach.

Main Methods:

• Implementing a hybrid maintenance strategy utilizing vacuum vessel ports and large access openings.
• Developing robotic handling systems for zero-human entry maintenance in hazardous environments.
• Focusing on engineering integration of maintenance into the tokamak architecture and reducing building costs.

Main Results:

• Established programs for developing service connections and in-vessel robotic technologies.
• Identified remountable magnet joints as critical for component replacement and strategy realization.
• Acknowledged high-risk factors due to low technology maturity and complex technical challenges.

Conclusions:

• The STEP maintenance strategy requires significant technological development, particularly for remountable magnet joints.
• An integrated design approach and multi-faceted technology development are crucial for managing risks and validating the design.
• Successful implementation of the maintenance strategy is essential for the realization of fusion energy production in STEP.