Application of the Bi-modal Master Curve Procedure to Determine the Fracture Toughness Lower Bound Curve

Research output: Contribution to report/book/conference proceedingsIn-proceedings paper


Institutes & Expert groups

  • EDF Lab Renardières - Moret-Loing-et-Orvanne
  • ORANO (previous AREVA) - France
  • Framatome - (ex-AREVA NP)

Documents & links


The lower bound fracture toughness curve plays a key role in assessing the safety integrity of nu-clear components, in particular the reactor pressure vessel. The construction codes such as ASME or RCC-M rely on a procedure based on the Pellini drop weight and Charpy impact tests to determine the so-called RTNDT, the reference temperature of nil-ductility transition. The latter determines the lower bound fracture toughness that is used for further structural integrity calculations. Nowadays, an alternative is available to directly measure the fracture toughness thanks to the master curve concept. The main objective of the present paper is to compare this innovative approach to the RTNDT-based method in particular for inhomogeneous materials.


Original languageEnglish
Title of host publicationContribution of Materials Investigations and Operating Experience to Light Water NPPs’ Safety, Performance and Reliability
Subtitle of host publicationFontevraud 9
PublisherSFEN - Société française d’énergie nucléaire
Number of pages10
Publication statusPublished - 16 Sep 2018
Event2018 - FONTEVRAUD 9 - Palais des Papes, Avignon , France
Duration: 17 Sep 201820 Sep 2018


Conference2018 - FONTEVRAUD 9
City Avignon
OtherContribution of Materials Investigations and Operating Experience to LWRs’ Safety, Performance and Reliability
Internet address


  • RPV, master curve, bi-modal, fracture toughness, lower bound curve

ID: 4402494