Conveners
04 Research Reactors and Particle Accelerators
- Paolo MUTTI (Institut Laue-Langevin)
- Akos HORTVATH (Centre for Energy Research, Hungary)
04 Research Reactors and Particle Accelerators
- Gordon Kohse (Massachusetts Institute of Technology, Nuclear Reactor Laboratory, Cambridge, Massachusetts, USA)
- Christelle REYNARD-CARETTE (Aix-Marseille University)
04 Research Reactors and Particle Accelerators: Parallel Intensive Oral Sessions
- Michal KOล ลครL (CV ลeลพ s.r.o.)
- Christophe DESTOUCHES (CEA/DES/IRESNE/DER/SPESI)
04 Research Reactors and Particle Accelerators
- Pattrick CALDERONI (INL)
- Jan WAGEMANS (SCK-CEN)
04 Research Reactors and Particle Accelerators: Parallel Intensive Oral Sessions
- Jean-yves FERRANDIS (IES, Univ Montpellier / CNRS, UMR 5214, F-34000, Montpellier, France)
- Yves PONTILLON (CEA, DES, IRESNE, DEC/SA3E)
04 Research Reactors and Particle Accelerators
- Vincent LAMIRAND (Ecole Polytechnique Fรฉdรฉrale de Lausanne)
- Christophe DESTOUCHES (CEA, DES, IRESNE, DER, Physics Safety Tests and Instrumentation)
Description
Oral Session
The collaboration on nuclear instrumentation started more than ten years ago between the CEA Experimental Physics, Safety experiment and Instrumentation Section and the Reactor Physics Division of the Joลพef Stefan Institute in the frame of bilateral agreement between CEA and the Slovenian Ministry of Higher Education, Science and Technology started in 2008.
More than ten development projects...
Gamma rays in nuclear reactors, arising either from nuclear reactions or decay processes, significantly contribute to the heating and dose of the reactor components. Zero power research reactors offer the possibility to measure gamma rays in a purely neutronic environment, allowing for validation experiments of computed spectra, dose estimates, reactor noise and prompt to delayed gamma ratios....
Three 0.95-mm$^2$ miniature fiber-coupled scintillators have been used to perform cm-wise resolution measurements of the thermal neutron flux within experimental channels of the SUR-100 facility, a zero power thermal reactor operated by the Institute of Nuclear Technology and Energy Systems at the University of Stuttgart. The detection system is developed at the รcole polytechnique fรฉdรฉrale de...
Recent subcritical VENUS-F experiments showed that fission chambers with a threshold deposit like U-238 can essentially improve the on-line sub-criticality monitoring with the beam interruption method, which is currently supposed to be the main method for the ADS MYRRHA. To suppress the uncertainty caused by fissions in the U-235 impurities, the fraction of U-235 in the U deposit should be...
Within the COLIBRI program, reactor noise related to fuel vibrations is investigated in the CROCUS zero power reactor. It consists in experiments on rod lateral displacement (static) and oscillation (dynamic) with different rodsโ numbers at various relevant amplitudes and frequencies. Its main motivation is the increased amplitudes in the neutron noise distributions recorded in ex- and in-core...
The interest of the scientific community in studying the three-dimensional propagation of induced perturbations inside nuclear reactor cores and their prediction with deterministic codes triggered the need for experimental full-core mapping systems. In this optic, the Laboratory for Reactor Physics and Systems Behaviour (LRS) at the รcole polytechnique fรฉdรฉrale de Lausanne (EPFL), Switzerland,...
Operation experience in many Material Testing Reactors, where beryllium moderator or reflector is used, has shown that accumulation of neutron absorbers, so-called poisons, has a non-negligible impact on both core performance and safety aspects due to n-Be interactions, and needs to be addressed properly in calculations. As a result, depletion of beryllium, called also beryllium poisoning, was...
Constant improvements of the computational power and methods as well as demands of precise and reliable measurements for reactor operation and safety require a continuous upgrade of the instrumentation. In particular, nuclear sensors used in nuclear fission reactors (research or power reactors) or in fusion facilities are operated under intense mixed neutron and gamma-ray fields, and need to...
In the nuclear reactor, it is crucial to measure key parameters such as neutron and photon fluxes or nuclear heating rate for a better understanding of the behavior of nuclear fuels or materials subjected to nuclear radiation. The coupling of different on-line measurement sensors is at the heart of these scientific objectives. The LIMMEX laboratory (Laboratory of Instrumentation and...
Education, training and isotopes production are the most important uses of the Moroccan 2 MW TRIGA Mark II reactor situated at the National Center for Energy Sciences and Nuclear Techniques (CNESTEN, Morocco). To develop new R&D projects in research reactors, the particular and advanced knowledge of neutron and photon flux distribution, within and around the reactor core, is crucial.
In...
Self-powered neutron detectors (SPND) have been a common diagnostic tool for intra-core neutron flux mapping in thermal nuclear reactors for more than 45 years. They are attractive flux monitors as they are compact, simple, and produce a signal proportional to local neutron flux without the need for an external source of power. Signal in these detectors is driven by electrons generated from...
This paper shows the results from the experiment at Joint Institute for Nuclear Research in Dubna and was carried out in 2014. The sample, using a special device, were placed in the accelerator chamber at a radius corresponding to the energy of protons 200 MeV at the current of 0.3 A. The position of the 200 MeV beam was determined by placing an aluminium foil inside the accelerator and...
The Centro de Micro-Anรกlisis de Materiales (CMAM) is one of the two research centres with an ion accelerator in Spain. It belongs to the Universidad Autรณnoma de Madrid (UAM) and the building that hosts the laboratory is at the university campus.
The equipment of the facility consists on an electrostatic ion accelerator with a maximum terminal voltage of 5 MV and six beam-lines dedicated to...
Precise measurement of neutron flux is crucial for reactor operation, especially during fast reactor transients. Measurement is valuable not only in reactor operation itself, but also for the prediction of reactor behavior via calculation or experiments. Especially fast transients with significant change in neutron flux are interesting and in order to analyse them, an advanced detection system...
Thermo-luminescent detectors are currently used to measure gamma doses in the medical and environmental surveillance fields. During the past few years, the CEA Reactor Studies Division tested and validated the use of these detectors for gamma flux characterization and nuclear heating measurements in mixed neutron/gamma fields of low power reactors. Doses were comprised between a few mGy and a...
There is a growing interest in fiber optic measurements for applications in radiation environments. They can be used to monitor environmental parameters such as temperature, size, pressure, chemical composition, irradiation doses and dose rates.... Often, the developed systems imply no propagation of the light beam outside the fiber, but for some applications, fiber optic is combined with an...
The availability of neutron fields with a high neutron flux, suitable for irradiation testing of nuclear instrumentation detectors (such as fission and ionization chambers and self-powered neutron detectors) relevant for applications in nuclear facilities such as material testing reactors (MTRs), nuclear power reactors and future fusion reactors is becoming increasingly limited. Over the last...
The nuclear heating named also โabsorbed dose rateโ is a quantity that it is essential to predict numerically in order to optimize the design of different elements of a nuclear research reactor and of its experimental irradiation devices for instance for safety, thermal and mechanical aspects and then to measure it accurately in order to analyze results associated to in-pile experiments. Heat...
A new material testing reactor Jules Horowitz Reactor (JHR) is under construction at CEA Cadarache. The materials to be irradiated will be placed into experimental devices around the reactor. Process and measurements of experimental devices will be carried out by command control. Programmable Logic Controller (PLC) dedicated on each experimental device will realize this function. Some...
The present article summarizes the development and testing of a reactivity modulation device developed by the French Atomic Energy Commission (CEA). It was installed in the CROCUS reactor of the Swiss Federal Institute of Technology in Lausanne (EPFL). Experimental tests were performed in the framework of a collaboration between CEA and EPFL.
The so-called PISTIL reactivity modulator...
JHR irradiation test devices must undergo a periodic inspection every 40 months (French Regulation rule). The first step of inspection proposal for application of non-destructive techniques (NDT) for these devices is presented, through examining the possible methods and locations that could be utilized in the reactor.
The selection of NDT methods depends mainly on the device geometry,...
Among numerous research projects devoted to the improvement of the nuclear fuel behavior knowledge, the development of advanced instrumentation for in-pile experiments in Material Testing Reactor is of great interest. In the frame of JHR reactor, new requirements have arisen creating new constraints. This research is carried out within the framework of a long-standing partnership between CEA,...
The high neutron and gamma fluxes as well as strong displacements per atom characterize conditions of materials testing reactors (MTRs). These research reactors constitute major support research facilities and allow experimental and real-condition studies of the behavior of fuels and inert materials (vessel, reflector, cladding, etc.) in an extreme radiation environment. These studies are...
This paper deals with the assessment of irradiation conditions in various experimental positions in the Jules Horowitz Reactor core and reflector. For this purpose, the CARMEN device is foreseen to measure neutron and gamma flux and nuclear heating in the experimental channels of the JHR [1]. CARMEN is an axially mobile measuring system composed of two fission chambers sensitive to both fast...
The Advanced Gas Reactor -5/6/7 (AGR-5/6/7) experiment was the fourth and final experiment in the AGR experiment series and completed irradiation in July 2020. It serves as the formal fuel qualification test for the TRISO fuels under development by the US Department of Energy. This experiment was designed to irradiate fuel particles at temperatures ranging from 800ยฐC โ 1500ยฐC. The high end of...
Confocal chromatic microscopy is an optical technique allowing measuring displacement, thickness, and roughness with a sub-micrometric precision [1]. Its operation principle relies on a wavelength encoding of the object position. The light emitted by a polychromatic source is transported by an optical fiber up to an optical system, called optical pen only composed of passive components and...
Research into materials and fuels for nuclear power reactors is carried out in so-called research reactors where various types of fuels and materials can be monitored online by in-core instruments. At the Halden reactor in Norway, online measurements such as cladding elongation, inner fuel rod pressure, fuel swelling, material creep and stress relaxation were based on Linear Variable...
Portable electronic neutron generators are an established technology that can be used for many lab and field applications. Offering significant regulatory and operational benefits over radionuclide neutron sources, they start to be more widely used at universities and research centres. Beside the established industrial applications (e.g., in logging or mining industry), applications are being...
The Nuclear Measurement Laboratory (LMN) at CEA Cadarache in France uses high-energy electron linear accelerators, LINAC (9-20 MeV), to characterize nuclear waste drums or study corium-water interaction. These high-energy accelerators allow to explore new examination modalities, such as active photon interrogation or dual-energy CT to scan large concrete objects with diameters up to 140 cm....
The possibility of using the fast neutron beam with the associated alpha particle technique (APT) by the specially designed tool for Carbon-to-Oxygen (C/O) nuclear well logging was investigated. Measurements were done to show the influence of borehole fluid, iron casing, and the cement around the casing on the C/O analysis. Tests were conducted by using fast neutrons, which is the conventional...
Materials and core components for the next generation power reactors technologies require testing that can be performed in existing research reactors. Such experiments employ devices dedicated to reflect the relevant thermal and neutron parameters simulating conditions present in, for example, but not limited to, HTR reactors. A novel thermostatic irradiation device named ISHTAR...
Devices that generate ionizing radiation that operate with a short pulse time are increasingly used in industry, healthcare, and scientific research. In the case of pulsed operation, these devices create pulsed ionizing fields, which have different properties compared to those experienced at stationary sources. Correct measurement of pulsed spaces is a challenge for manufacturers and users, as...
The good knowledge of gamma spectrum in vicinity of nuclear reactor core is essential in characterization of radiation field. It is important for ensuring of radiation safety, but well described gamma field can be used also for testing of radiation measuring devices. The field in vicinity of reactor core is interesting for testing because in contrary to commonly use gamma fields formed by...
The CABRI experimental pulse reactor, located at the Cadarache nuclear research center, southern France, is devoted to the study of Reactivity Initiated Accidents (RIA). When certain conditions (mostly temperature, pressure and flowrate conditions) are obtained, a power excursion, triggered by the 3He reactivity injection system, is performed on a nuclear fuel test rod in order to simulate a...
Fission chambers are widely used in nuclear reactors, either to occasionally probe the neutron flux maps in nuclear power plants or as part of the nuclear instrumentation used in research reactors to characterize neutron flux levels in irradiation locations. In the frame of the Jules Horowitz Reactor (JHR) under construction at the CEA CADARACHE site, the Instrumentation Sensors and Dosimetry...
Neutron imaging is a powerful tool in the field of non-destructive testing that utilizes the unique attenuation properties of neutrons to image high-density objects. The Penn State Breazeale Reactor (PSBR) at the Radiation Science and Engineering Center (RSEC) has had a neutron radiography facility for the last several decades. With the installation of a new core moderator assembly and new...
Specific research reactors are capable of reproducing reactivity injection accidents in order to study the behavior of the nuclear fuel pins in accidental situations. The CABRI experimental pulse reactor, funded by IRSN (French Institute for Radioprotection and Nuclear Safety) and located at the Cadarache research center, is used to simulate power transients typical of reactivity initiated...
