Investigation of fission chamber response in the frame of fuel debris localization measurements at Fukushima Daiichi

Autor: R. Pissarello, C. Thiam, H. Hamrita, B. Krausz, F. Carrel, Camille Frangville, F. Laine, Jonathan Dumazert, K. Boudergui, R. Delalez, A. Sari, M. Trocmé, Romain Coulon
Přispěvatelé: Laboratoire Capteurs et Architectures Electroniques (LCAE), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire National Henri Becquerel (LNHB), ONET Technologies, This work was supported by Mitsubishi Research Institute, Inc., Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département d'instrumentation Numérique (DIN (CEA-LIST)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Fission chamber
020209 energy
Nuclear engineering
Gamma irradiation trials
Fuel debris localization
02 engineering and technology
Neutron flux measurement
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
7. Clean energy
01 natural sciences
law.invention
modelling
U235
neutron
law
LINAC
0103 physical sciences
0202 electrical engineering
electronic engineering
information engineering
MCNP
Neutron
Irradiation
[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]
signal processing
damaged nuclear reactor
nuclear instrumentation
instrumentation
Radiation
primary containment vessel
irradiation
dosimetry
010308 nuclear & particles physics
dismantling
dose
Particle accelerator
MCNP6 simulation
Nuclear reactor
simulation
Debris
Neutron temperature
Fukushima daiichi
13. Climate action
radioactivity
Environmental science
nuclear reactor
ionizing radiation
Fukushima Daiichi
Zdroj: Radiation Measurements
Radiation Measurements, Elsevier, 2020, 130, pp.106223. ⟨10.1016/j.radmeas.2019.106223⟩
Radiation Measurements, 2020, 130, pp.106223. ⟨10.1016/j.radmeas.2019.106223⟩
ISSN: 1350-4487
Popis: International audience; This work aims at assessing the performance of a 235U enriched fission chamber in order to localize fuel debris, prior to dismantling operations, in a flooded primary containment vessel of a damaged nuclear reactor such as Fukushima Daiichi. Based on both a comprehensive scan of the environment and the detection of neutrons emitted by the melted core, fuel debris can be localized. In this paper, we carry out a simulation study using the MCNP6 code to investigate fission chamber response in the frame of fuel debris localization measurements in a damaged nuclear reactor. The CFUF34 fission chamber (manufactured by PHOTONIS) and the primary containment vessel of Fukushima Daiichi Unit 1 were chosen to conduct this work. Impact of different parameters were investigated with MCNP6, such as: neutron energy, water temperature, fission chamber position (altitude, lateral shift, and rotation), and sensitivity loss due to sediments potentially covering fuel debris. In summary, we show that fuel debris should be sought by their thermal neutron signature at a distance of a few centimeters and that potential rotational movements of the fission chamber up to 60° have a limited impact on signals measured. We also show that sensitivity loss due to sediments potentially covering fuel debris has been evaluated on the order of a factor 10 considering a 30 cm-thick sediment layer. On the other hand, experiments were performed to assess the impact of a strong gamma dose rate on fission chamber measurements. These irradiation trials involved a CFUE32 fission chamber (also manufactured by PHOTONIS) available in our laboratory and three different irradiation means: an X-ray tube, an 192Ir source, and a linear electron accelerator. These experiments enable to draw the conclusion that the fission chamber is not impacted by the gamma dose rate up to 104 Gy h−1, which is in good agreement with specifications provided by the manufacturer (PHOTONIS). In addition, no performance degradation was observed after an integrated gamma dose of 2200 Gy on the fission chamber in a 10 min irradiation. However, when the fission chamber is irradiated by gamma dose rates above 104 Gy h−1 (upper limit of the operating domain specified by PHOTONIS), a significant gamma background is observed. Nevertheless, as the gamma dose rates at Fukushima Daiichi should not exceed 103 Gy h−1, fission chamber measurements performed towards fuel debris localization in the primary containment vessels of the units would not be affected by the severe gamma-ray irradiation.
Databáze: OpenAIRE
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