Session: MF-20-01 Material Quality and Failure Analysis-1

Paper Number: 152923

152923 - Fracture Toughness Testing Qualification Strategy of the Hinkley Point C Uk Epr 

Abstract: 

The UK approach to regulatory compliance arrangements for nuclear safety classified pressure equipment is viewed as amongst the most stringent worldwide, and comprises a set of interrelated regulations, regulatory expectations, and guidance.  In addition to this, the UK EPR at Hinkley Point C (HPC) is the first civil nuclear power plant under construction since Sizewell B in the 1980’s and is therefore considered to be a first of a kind nuclear construction project in the UK.

In the UK, components whose failure would result in intolerable radiological release or, would compromise the plant directly or from secondary consequences, would be considered as Incredibility of Failure (IOF) or High Integrity Components (HICs). For such components, gross failure can be discounted from the design basis, and the requirements and expectation go beyond those normally considered for Class 1 components. For HICs, the UK’s Office for Nuclear Regulation (ONR) does not accept the use of a nuclear code alone, and such components require the development of dedicated and specific structural integrity safety cases that go beyond a nuclear manufacturing code such as ASME or RCC-M.

For HPC, the HICs are the Reactor Pressure Vessels, Steam Generators, Pressurisers, Main Steam Line (MSL) and Main Steam Isolation Valves (MSIV); extensive fracture mechanics testing has been performed across these components to substantiate the structural integrity claims in the safety cases and provide the materials performance data necessary to qualify the forgings used in fabrication.

This 6+ year program has so far seen the generation of a compendium of upper shelf J-resistance fracture toughness test data generated in accordance with ASTM E1820 across multiple replica forgings used to manufacture components across two reactor units, to understand ductile fracture initiation and tearing resistance at pressurised water reactor operating conditions and provide the assurance to the UK nuclear regulator that the materials performance data have been rigorously evaluated.

This paper outlines the materials testing strategy, technical requirements, and quality arrangements associated with the fracture toughness qualification of HPC’s HICs performed by Amentum, Framatome, and EDF.

Presenting Author: Adam Cooper Amentum

Presenting Author Biography: TBC

Authors:

Adam Cooper Amentum
Andrew Harrison Amentum
Jacob Knight EDF Energy
Lorenzo Mezzera EDF Energy