Assessment of on-line burnup monitoring of pebble bed reactor fuel by passive neutron counting

Monte Carlo studies on the burnup measurement for the high temperature gas cooling reactor

“…The high temperature gas cooling reactor (HTGR) is drawing great attention from scientists because of its intrinsic safety [1][2][3]. In the type of the modular pebble bed reactors (MPBR), the fuel ball, consisting of a core of uranium compound fuel mixed with phenolic resin and a coat of graphite, undergoes a multi circulation during the operation of the reactor.…”

Conditioning the γ spectrometer for activity measurement at very high background

“…Fuel balls undergo a multipass cycle in modular pebble bed reactors (MPBR). Because of the serious inaccuracy of the computational method, which is conventional for performing the in-core fuel management in existing water reactors, a non-destructive determination of the burnup is desired in order to provide the distributed controlling system with an online circulation/discharge judgement on a pebble-bypebble basis in some bed-like reactors [1,2]. Gamma ray spectrometry has been proposed as an effective non-destructive method to determine the burnup [3][4][5][6][7] as well as the spatial irradiation distribution [8,9] by measuring the activity (activity ratio) of given monitor nuclide(s).…”