VeryFuel, a Liquid Scintillator-Based Fast Neutron Counter for Fresh Nuclear Fuel Measurements

Year
2017
Author(s)
Jonathan S. Beaumont - International Atomic Energy Agency, Vienna International Centre
Jonathan S. Beaumont - International Atomic Energy Agency, Vienna International Centre
Tae Hoon Lee - International Atomic Energy Agency, Vienna International Centre
Matteo Corbo - CAEN S.p.A
Mikhail Mayorov - International Atomic Energy Agency
Massimo Morichi - CAEN SyS Srl
Francesco Pepe - CAEN S.p.A
Claudio Raffo - CAEN S.p.A
Abstract
The VeryFuel is an NDA tool for verification of modern fresh fuel assemblies. It is a liquid scintillator-based instrument detecting fast neutrons from induced nuclear fissions. The VeryFuel has the capability to measure the 235U linear mass density with unprecedented speed and much lower systematic uncertainty in presence of burnable poisons. Tests have demonstrated verification of 235U enrichment in 17x17 PWR with statistical uncertainty on coincidence rates lower than 1% in an acquisition time of 15 minute. The presence of 24 fuel rods containing Gd at 10% weight in 17x17 PWR assemblies causes a systematic bias of around 3-4%, approximately half as much as current alternatives.