Working Group on Integrity of Components and Structures (WGIAGE)

    Introduction

    The mandate of this working group is to advise the CSNI on the topical basis for management of plant ageing and to propose general principles to maintain the integrity of systems and components. The main topics investigated in this area include metal components, concrete structures, seismic behaviour of structures and components and the ageing of wire systems.

    OECD member country representatives are joined at the group's meetings by representatives from the IAEA, the European Commission and JRC Petten.

    Mandate

    The Working Group on Integrity of Components and Structures has a general mandate to reflect on the logical basis for the maintenance of the integrity of nuclear power plant components, systems and structures, and to propose general principles on the optimal ways of dealing with challenges to integrity - in particular those from ageing. Specifically the mandate will be:

    • The working group shall constitute a forum to exchange views, information and experience on generic technical aspects of integrity and ageing of components and structures, and review, as necessary, national and international programmes concentrating on research, operational aspects and regulation.
    • The working group shall stimulate, in relevant technical areas, new research and recommend possible international co-operative projects.
    • The working group shall develop common technical positions on specific integrity issues of operating and new nuclear power plants, and identify areas where further work is needed.
    • The working group shall discuss the potential impact of ageing and other challenges to integrity on the safety, regulation and operability of operating and new nuclear power plants.

    Programme of work

    The main topics investigated by this working group include: the integrity of metal components; the integrity and ageing of concrete structures; and the seismic behaviour of structures and components.

    Lifetime management remains an important topic for the working group. A status report on risk-informed, in-service inspection (RI-ISI) methodologies was completed, and the group is now actively working on a benchmark study on RI-ISI methodologies. Reactor pressure vessel integrity is being addressed through a benchmark on probabilistic structural integrity methods.

    An extensive report on concrete containment integrity was issued during 2006. The workshop on corrosion and long-term performance of reinforced concrete in nuclear waste facilities held in Cadarache, France on 27-30 March 2006 provided insights on structural and regulatory issues.

    The workshop on seismic input motions, incorporating recent geological studies was held in Japan on 15-17 November 2005 and completed a series of workshops on seismic input motions. Methods to calculate seismic input motions for nuclear power plants and related uncertainties continued to be explored through close co-operation with geologists and seismologists.

    Integrity of metal components and structures

    The integrity of metal components and structures sub-group's recent activities include:

    • Developing a benchmark on the probabilistic structural integrity of a PWR reactor pressure vessel (PROSIR);
    • Compiling a report which collected information on primary water stress corrosion cracking (PWSCC) in nickel-based alloys used in the reactor vessel head penetrations and other components - in particular Alloy 600 and its associated welds.
    • A report examining plant ageing and lifetime management is currently in preparation.

    Ageing of concrete structures

    The integrity and ageing of concrete structures sub-group has recently been focusing on the preparation of a strategy report that identifies and ranks challenges for concrete structures for operating and new and advanced reactors.

    Seismic behaviour of components and structures

    The seismic behaviour of structures and components sub-group's recent activities include:

    Workshops and meetings

    Working Group on Integrity of Components and Structures (IAGE)
    Seismic engineering knowledge transfer seminar

    Nuclear Research Institute Rez, Czech Republic
    21-25 November 2011

    Contact

    Olli Nevander,


    Last reviewed: 10 April 2014