August 03, 2020

Framatome continues investigations of stress relieving heat treatment processes

As part of its investigations into local stress-relieving heat treatments (SRHT), Framatome is studying the temperatures applied to welded joints on pipework connected to the steam generators during on-site replacement operations. The calculation and test-based verification program requires additional substantiation work to be conducted, in particular with regard to the RCC-M technical reference framework*. Framatome is keeping the operator EDF informed. The analyses carried out at this stage confirm that the mechanical integrity of the parts concerned is not impaired.

*This RCC-M framework or code corresponds to a set of French design and construction rules for the mechanical components of PWR nuclear Islands. It applies primarily to mechanical equipment that is safety classified and subjected to pressure. It also applies to certain non-pressurized components such as RPV internals, supporting elements for classified components, storage tanks and containment penetrations. RCC-M frames many of the manufacturing criteria such as choice of materials and conditions of supply, fabrication and test methods to be implemented, eligibility criteria for detected defects, etc.