Speaker
Liam Worth
(ITER Organization)
Description
The ITER vacuum system will be one of the largest, most complex vacuum systems ever to be built and includes a number of large volume systems such as the Cryostat (~ 8500 m33), Torus (~1330 m33), and the Neutral Beams (~180 m33 each).
The vacuum system comprises of custom and commercially available components and adapted commercial vacuum technology. For a component with a nuclear safety function validation of the design is required. Validation may take different forms including by analysis and/or test. Additionally the manufacturing must be controlled to ensure the equipment conforms to the validated design. Where similar components are used a program is in place to standardize these components to a common design.
Leaks are expected to account for a loss of operational availability if timely localisation and repair cannot be performed. The design of the ITER in-vessel systems are such that localisation of a leak must be performed with sub-centimeter resolution such that the risk of removing a leak tight component in error is reduced.
Due the progression to an active environment, traditional methods of leak localization may not be applicable. Hence a challenge is to develop methods of leak localization capable of operation in the ITER environment, with a minimum of human intervention.
In this paper an overview is given of the nuclear safety functions of the vacuum system and different routes to achieving validated functions provided for a variety of components. Experience gained from the design, validation and manufacturing process is described.
A concept for the localization of water leaks based on the spectroscopic detection of plasma excited hydroxyl (-OH) is described. Also, details of a methodology, based on the pressurisation / depressurisation of water feeds, for the localiation of leaks from the in-vessel blanket system is provided herein.
Co-authors
Alexander Antipenkov
(ITER Organization, St Paul Lez Durance, France)
Bastien Boussier
(ITER Organization, St Paul Lez Durance, France)
Eamonn Quinn
(ITER Organization, St Paul Lez Durance, France)
Liam Worth
(ITER Organization, St Paul Lez Durance, France)
Matthais Dremel
(ITER Organization, St Paul Lez Durance, France)
Robert Pearce
(ITER Organization, St Paul Lez Durance, France)