Component Qualification in Lead Bismuth Eutectic for Remote Handling in MYRRHA

Date: 24/04/2017
Author: Caers, B.; Van Tichelen, K.; Schuurmans, P.

Published in: 2017 - ICAPP - International Congress on Advances in Nuclear Power Plants, Japan

MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is a flexible fast-spectrum research reactor under design at SCK•CEN, the Belgian Nuclear Research Centre. MYRRHA is a pool-type reactor with Lead Bismuth Eutectic (LBE) as the primary coolant. Conceived as an accelerator driven system prototype, it is able to operate in sub-critical mode. Operating in critical mode, MYRRHA is identified as the European Technology Pilot Plant for the Lead Cooled Fast Reactor, one of the Generation IV reactor concepts. The MYRRHA design requires the refuelling and fuel reshuffling inside the liquid LBE, using a submerged robotic system.  Due to the particular nature of the reactor coolant, little test data is available for robotics component properties and failure mechanisms. Thus one of the central goals of the remote handling research is to test potential components for the fuel manipulation system (i.e. bearings, springs, electrical cables) to gain insight into the possibilities of working in LBE under MYRRHA's specific circumstances. Testing of remote handling components is performed in RHAPTER, the Remote HAndling Parts TEst Rig at SCK•CEN.  The test rig consists of a vessel containing liquid LBE in which different test modules can be submerged, with external drive and load motors, a vacuum and cover gas system and diagnostic instrumentation such as accelerometers and torque sensors.  The facility has been in use since 2011, with the main focus on ball bearings for remote handling operations. This paper gives a description of RHAPTER and of the test module used for ball bearings.  It reviews the analysis methods, both online and offline, used in determining failure mechanisms and fault progression in the bearings.  It then focuses on the results of the ball bearings test, discussing the effect of different materials and material combinations on bearing performance in LBE.