• February 18, 2020

Evaluating ITER pipe weld integrity

Evaluating ITER pipe weld integrity

Evaluating ITER pipe weld integrity 1024 334 Iain Forcer

The process of remotely connecting pipes within the ITER environment is challenging for many reasons, not least due to the levels of radiation and space constraints.

In areas of ITER where defects could be present in safety-critical, welded structures it is imperative to implement standardised methods to evaluate them. Visual and leak/pressure tests are available to assist in the validation, but 100% volumetric inspection is required by the nuclear standards and regulators.

The ability to perform checks as part of the weld acceptance process is a priority across ITER and critical for the safety, reliability and viability of the operational facility. Radiography, the most mature and recognised technology, is not feasible without significant, application specific, development. In addition, verifying the welds between pipe walls that are as thin as those that will be found in ITER (~3mm) is unproven using other applicable technologies and not covered by current standards.

IRTF (ITER Robotics Test Facility) is an IO-UKAEA collaborative program focusing on ITER remote handling feasibility and risk reduction activities. Establishing a weld acceptance process for ITER is the 11th IRTF project, with the first phase of the work split into four work packages.

UKAEA’s RACE (Remote Applications in Challenging Environments) and JAM (Joining and Advanced Manufacturing) are working together to investigate possible non-destructive evaluation (NDE) methods that can check the integrity of the welds in the ITER pipes.

RACE has hosted the IRTF programme since 2017 and worked on projects that include remotely cutting and welding pipes that will be used in ITER. Chris Lamb, ITER Programme Lead at RACE, added:

“We know from our experience with IRFT that it is vital that ITER can clarify the integrity of the pipe welds, in situ. Utilising RACE and JAM provides them with the combined expertise they require and is a great example of the breadth of capabilities that UKAEA can offer these projects.”

JAM has expertise in assessing the suitability of technologies and components for fusion environments. Heather Lewtas, JAM Programme Manager, said:

“There is nothing on the market that fulfils ITER’s weld acceptance requirements. Whilst the JAM programme is relatively new, the experience of the people working here and the fantastic network of experts we have developed throughout academia and industry is unparalleled and I am confident in their ability solve this challenge.”

In addition to using in-house facilities, UKAEA will look to engage with industry and academia, once the first work package has been completed in Spring 2020.