Flow-induced vibration experiment in fuel pin bundle with heavy liquid metal flow. Test section design and measurement methods

The present paper describes the experimental setup for flow-induced vibration in a fuel pin bundle test section with flowing lead. The test section is a 37-pin mock-up representative of the GEN-IV ALFRED fuel assembly and is manufactured to investigate the turbulence-induced vibrations in the pins. The pins are instrumented with longitudinal strain gauges (SGs), and with three SGs per monitoring point, the displacement signal can be recovered in terms of amplitude and frequencies. To achieve this goal, a complex algorithm is implemented in the data acquisition control system of the test section. The test section will be installed in the Heavy Liquid metal Experimental loop for Nuclear Applications (HELENA) facility at the ENEA Brasimone R.C., in which a mechanical pump for lead circulation is present. The test matrix is proposed with the mass flow rate varying from 10 to 50 kg/s and a constant temperature of 450 degrees C for all the tests. Briefly, the experimental procedure is presented to carry out the experimental campaign.