TY - GEN

T1 - Radiation hardness testing of an organic liquid scintillator detector for use in high dose rate accident response scenarios

AU - Jones, Ashley Richard

AU - Joyce, Malcolm John

AU - Griffiths, Arron

AU - Lennox, Barry

AU - Potts, Dale

AU - Watson, Simon

AU - Katakura, Jun-ichi

AU - Okumura, Keisuke

AU - Kim, Kangsoo

AU - Katoh, Michio

AU - Nishimura, Kazuya

AU - Sawada, Ken-ichi

PY - 2016/10/3

Y1 - 2016/10/3

N2 - Organic liquid scintillation detectors offer the advantage relative to many alternatives that they are sensitive to both fast neutrons and gamma rays, whilst radiation type can be discerned on the basis of pulse-shape discrimination. Mixed radiation fields of this type can arise in the context of reactor accidents via, for example, 137Cs (gamma) and 244Cm (neutrons). However, performance degradation of such scintillators, such as EJ-301, is a significant possibility that might limit the use of this technology in accident response applications. The premise behind the high dose rate testing of such a liquid scintillator described in this paper is for fuel debris characterisation at Fukushima Daiichi, which has expected dose rates of up to 1000 Gy/hr in close proximity to fuel debris. The tests carried out for this investigation involved using the 60Co gamma irradiation facility at the Dalton Cumbria Facility, Cumbria, United Kingdom to expose the detector to a similar dose rate to that which is estimated within the primary containment vessel for survivability tests. Radiation hardness tests have rarely been reported for such devices and it is expected that the performance will be dependent on the survival of the window of the photomultiplier tube rather than the liquid scintillant itself. A major advantage of the use of this detector is its physical size, due to the limitations on access into Fukushima reactors physical space is a premium. The research described in this paper presents the results of the dose rate exposure of the detector before signal was lost with the total dose observed providing information on any degradation affecting the performance of the device post-irradiation

AB - Organic liquid scintillation detectors offer the advantage relative to many alternatives that they are sensitive to both fast neutrons and gamma rays, whilst radiation type can be discerned on the basis of pulse-shape discrimination. Mixed radiation fields of this type can arise in the context of reactor accidents via, for example, 137Cs (gamma) and 244Cm (neutrons). However, performance degradation of such scintillators, such as EJ-301, is a significant possibility that might limit the use of this technology in accident response applications. The premise behind the high dose rate testing of such a liquid scintillator described in this paper is for fuel debris characterisation at Fukushima Daiichi, which has expected dose rates of up to 1000 Gy/hr in close proximity to fuel debris. The tests carried out for this investigation involved using the 60Co gamma irradiation facility at the Dalton Cumbria Facility, Cumbria, United Kingdom to expose the detector to a similar dose rate to that which is estimated within the primary containment vessel for survivability tests. Radiation hardness tests have rarely been reported for such devices and it is expected that the performance will be dependent on the survival of the window of the photomultiplier tube rather than the liquid scintillant itself. A major advantage of the use of this detector is its physical size, due to the limitations on access into Fukushima reactors physical space is a premium. The research described in this paper presents the results of the dose rate exposure of the detector before signal was lost with the total dose observed providing information on any degradation affecting the performance of the device post-irradiation

M3 - Conference contribution/Paper

BT - Proceedings of Hotlab 2016

PB - SCK.CEN

T2 - Hotlab

Y2 - 3 October 2016 through 6 October 2016

ER -