Context and challenges

During the 2013 outage on reactor 1 at Heysham Power Station, an anomalous result was detected during the Teletest NDT inspection of 1D1 boiler pod spine. The boiler spine is a key component in the support arrangements for the boiler and its mechanical integrity is of critical importance for reactor safety. Further inspections enabled to identified that the most likely source of this anomalous was a crack in weld 12.3. The boiler spines that were on the other 7 boilers have been inspected but no further anomalous results were detected.

The long-term solution that would allow reactor 1 to return to full power is to perform a modification in the area of weld 12.3 that would control the temperature of the weld material so as that crack creep will not occur. This modification has been achieved by inserting an insulating material in the region of the weld. In order to do this and to ensure that the insulating material remained in place, it was necessary to block off existing holes in the boiler spine.

This client, leader in nuclear, has appointed Assystem and other partners, to provide project management and design expertise, in order to confirm that all optioneering studies, detail design, manufacturing, testing and delivery correspond with the client’s requirement. Delivery of the design documentation, equipment and training was expected to be completed by the end of March 2015.

Project scope

Assystem carried out optioneering studies and developed prototypes for the proposed solutions. This included the design, development, manufacturing (as well as supporting the implementation and commissioning) of plant modifications. This included:

  • An Integrated multi-stakeholder Project Management Team delivering planning, spending, supply chain, quality and resource management.
  • Management of design activities and substantiations including test specifications, test results, quality plans, functional specifications, technical files, engineering retrieval plan, documentation register
  • A site-based multi disciplined engineering team to complete the deployment, installation and commissioning of the equipment, fully in accordance with the client site standards and procedures
  • Preparation of as-built and lifetime quality records
  • Preparation of procedures including: method statements, design risk assessment, test risk assessment, emergency recovery plan
  • Delivery of a design manufacturing pack, including the prototype and trials
  • Project close-out report

Client benefits

  • Strong collaboration, information sharing and reporting across all key stakeholders, including customer and supply chain thanks to the integrated Project Management approach delivered
  • Compliance with client requirements related to all optioneering studies, detail design, manufacture, testing and delivery
  • Compliance of Quality Grades 1 and 2 related to the manufacture of all specified mechanical items, according to the client standards and procedures. Indeed, due to the environment in which the plugs were being used in, limitations into the materials composition (maximum levels of Carbon, Chromium, etc) required to deliver materials test certificates to confirm their composition (as part of Quality Records, along with inspection certificates)
  • Reduction in the outage duration thanks to the effective deployment of the solution. Indeed, the implementation of the new items has taken place during statutory outages.
  • Reactors on site operating now at full load until the end of their life, circa 15 years.

Nuclear & studies: related projects

Concept design for the STEP fusion tokamak

Know more

Realisation of a BIM model for the dismantling of a nuclear reactor

Know more

Quality inspection of the construction and installation works of structures and systems for a nuclear power plant

Know more

A question, a project?

Contact Us