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International audience; Within the scope of developing the experimental reactor means for the Jules Horowitz reactor (JHR) in France, certain R&D actions are currently focusing on technological building bricks. The action covered in this paper concerns fuel irradiation devices, in particular the fabrication and testing of leak tight feedthroughs equipped with optical fibres under thermal hydraulic conditions (155 bar and 100°C) that are representative of those in certain irradiation devices heads operating under pressurised water reactor (PWR) conditions. The test performed with these leak tight feedthroughs lasted five days and was representative of certain experimental power ramp-up scenarios on a fuel rod (conditioning, ramp-up, high power plateau for 24 hours, and cooling). The results of this test make it possible to validate the recommended technology. It therefore seems feasible to implement innovative instrumentation equipped with optical fibres in irradiation devices operating under similar experimental conditions. Following a general description of the project and the JHR facility currently under construction at the CEA Cadarache centre in France, this paper describes the relevant fuel irradiation devices. We have focused on the leak tight feedthroughs going through the device head, in particular those containing the optical fibres. We discuss the tests performed, their results and several future prospects with respect to the utilisation of optical fibres as a means to support the development of innovative instrumentation. IGORR-RRFM conference 24-28 th March 2019, Jordan 2-11

National audience; Nous présentons ici les mesures de compaction sur divers échantillons de fibre optiques irradiées en cœur de réacteur BR2 à Mol en Belgique à 1et 3.10$^{19}$ n$_{rap}$/cm$^2$ (E> 1 MeV) et des doses gamma de 0.5 et 1.5 GGy (irradiation SAKE2). La température d'irradiation était de 250°C$\pm$25°C. La compaction à 3.10$^{19}$ n$_{rap}$/cm$^2$ est sensiblement plus élevée : $\sim$0.5% que celle mesurée après l'irradiation SAKE 1 ($\sim$0.25%) à des fluences au moins égales et une température un peu plus élevée. De légères variations apparaissent à mêmes conditions pour des fibres différentes.Des mesures sur des échantillons découpés dans un bloc de silice donnent une variation de longueur similaire.Des mesures d'indice optique ont aussi été réalisées sur des échantillons préalablement mesurées en compaction. Ces mesures ont été réalisées par iXblue Photonics sur le système IFA-100 d’Interfiber Analysis qui utilise un montage interférométrique de type Mach-zendher pour reconstituer le profil d’indice de réfraction. Après irradiation à 3.10$^{19}$ n$_{rap}$/cm$^2$, le rapport des variations relatives d’indice et de compaction est assez bien en accord avec la valeur rapportées par Devine, valeur associée à la formule de Lorentz Lorentz.

National audience; The DIstributed Sensing for COrium Monitoring and Safety (DISCOMS) project considers the use of optical fiber sensing cables embedded into the concrete floor under the reactor vessel for remote monitoring of a severe nuclear accident. This presentation focuses on the selection and testing of single-mode optical fibers with limited radiation-induced attenuation (RIA).

International audience; The Fukushima-Daiichi nuclear disaster showed that the need for safety must always prevail. This paper discusses the development of remote monitoring technologies to improve Nuclear Power Plants (NPPs) safety, in operation (Pressurized Water Reactors), under construction (the EPR reactors, i.e. the GEN 3 PWR), or for any other next generations of reactors. At Fukushima, the total loss of electrical power supplies has quickly led most of the instrumentation inoperative and the operator (TEPCO) with no way to monitor the status and the evolution of the accident. To overcome these important drawbacks, advantage can be taken from the considerable potential of distributed sensing technologies based on both "Optical Fiber Sensors" (Raman, Brillouin, and Rayleigh Reflectometries) and long-length "Self Powered Neutron Detectors" (SPNDs). The goal consists in inquiring about the status of the third barrier of confinement and to define possible mitigation strategies in case of severe accident, namely: i) reactor pressure vessel breakthrough and corium relocation outside the vessel, ii) concrete basemat erosion and iii) corium cooling. Such monitoring should consist in "sensing cables" embedded in concrete basemat below the reactor vessel and interrogated from a rear base where operators can work safely. In this context, DISCOMS, which stands for "DIstributed Sensing for COrium Monitoring and Safety", is a five-year project, managed by the French National Research Agency (ANR), dealing with the NPP safety improvement, from normal situation to severe accidents. Monitoring phases include reactor vessel breaching, corium flow, along with post-accidental period (corium cooling ex-vessel). Thus, optical fibers selected for their resistance to ionizing radiations and long length SPNDs, both judiciously deployed within the reactor concrete basemat, and the structures around it, will provide a useful real-time or on-demand monitoring, in normal operation, and more important in accidental and post-accidental situations.

International audience; The Fukushima-Daiichi nuclear disaster showed that the need for safety must always prevail. This paper discusses the development of remote monitoring technologies to improve Nuclear Power Plants (NPPs) safety, in operation (Pressurized Water Reactors), under construction (the EPR reactors, i.e. the GEN 3 PWR), or for any other next generations of reactors. At Fukushima, the total loss of electrical power supplies has quickly led most of the instrumentation inoperative and the operator (TEPCO) with no way to monitor the status and the evolution of the accident. To overcome these important drawbacks, advantage can be taken from the considerable potential of distributed sensing technologies based on both "Optical Fiber Sensors" (Raman, Brillouin, and Rayleigh Reflectometries) and long-length "Self Powered Neutron Detectors" (SPNDs). The goal consists in inquiring about the status of the third barrier of confinement and to define possible mitigation strategies in case of severe accident, namely: i) reactor pressure vessel breakthrough and corium relocation outside the vessel, ii) concrete basemat erosion and iii) corium cooling. Such monitoring should consist in "sensing cables" embedded in concrete basemat below the reactor vessel and interrogated from a rear base where operators can work safely. In this context, DISCOMS, which stands for "DIstributed Sensing for COrium Monitoring and Safety", is a five-year project, managed by the French National Research Agency (ANR), dealing with the NPP safety improvement, from normal situation to severe accidents. Monitoring phases include reactor vessel breaching, corium flow, along with post-accidental period (corium cooling ex-vessel). Thus, optical fibers selected for their resistance to ionizing radiations and long length SPNDs, both judiciously deployed within the reactor concrete basemat, and the structures around it, will provide a useful real-time or on-demand monitoring, in normal operation, and more important in accidental and post-accidental situations.

International audience; Within the framework of the renovation of the MASURCA research reactor [1], the development of the future instrumentation for physics measurements has to come along with a better control of the conditions in which they are performed. One of the main goals is to improve the masteryof temperature effects that affects all reactivity measurements. The assessment of the temperature correction coefficient actually suffers from a large uncertainty (~20%, k=2) due to the difficult establishment of the average temperature representative of the core fuel part. Increasing the numberof temperature measurement points, currently limited to less than 20, is clearly part of the solution. Due to some set-up constraints specific to the MASURCA facility, the use of miniature sensors allowing quasi-distributed temperature measurements without perturbing the experiments seems promising candidates. In addition to their sensing performances (1°C of precision for a temperature range going from 20°C to 100°C), these temperature sensors must withstand the radiation environments associated with MASURCA that mainly consists in a moderate neutron fluence (up to 1014n/cm²).Based on the feedback obtained in previous studies [2-6] achieved in more severe conditions (higher temperature and high neutron and gamma fluences), and taking advantage of the framework of the NEEDS [7] initiative, CEA and CNRS/LabHC have decided to start the SOMETIME projectdedicated to the design and the qualification of in-core and on-line quasi-distributed temperature measurements systems based on optical fibre Bragg grating sensors (FBG). This kind of sensor will enable online centimetric temperature profiles monitoring using a single optical fibre, thus allowing to minimize both the intrusivity and the induced thermal perturbation in the fuel element compared to the dozen of thermocouples required to get today’s the same profile.In this paper we present the NEEDS initiative, the overall context and the objectives of this project, together with the experimental set-up used in the EOLE facility [8]. Several kinds of FBG temperature transducers have been characterized during a preliminary testing campaign performed inEOLE reactor (2014): their evolution during the irradiation (few 1013n/cm²) is described with a specialfocus on the Bragg wavelength shift with respect to the neutron fluence. Finally, we detail the coming work for the second part of the SOMETIME project which will be dedicated to qualify thefunctionality of a representative FBG temperature instrumentation together with the challenging task of FBG arrays packaging and insertion within a real MASURCA fuel element.[1] W. AssaI, J.C. Bosq, F. Mellier “Experimental Measurements at the MASURCA Facility” First International Conference on Advancements in Nuclear Instrumentation Measurement Methods and their Applications (ANIMMA), Print ISBN - 978-1-4244-5207-12009 IEEE[2] S. Girard, Y. Ouerdane, A. Boukenter, C. Marcandella, J. Bisutti, J. Baggio, and J-P. Meunier, “Integration of Optical Fibers in Radiative Environments: Advantages and Limitations”, IEEE Transactions on Nuclear Science, vol. 59 (4), pp. 1317 – 1322, 2012.[3] A. Morana, S. Girard, E. Marin, C. Marcandella, P. Paillet, J. Périsse, J.-R. Macé, A. Boukenter, M. Cannas and Y. Ouerdane, "Radiation tolerant fiber Bragg gratings for high temperature monitoring at MGy dose levels", Optics Letters, Vol. 39, No. 18, September 15, 2014[4] G. Cheymol, A. Gusarov, B. Brichard; "Fibre Optic Extensometer for High Radiation and High Temperature Nuclear applications”; IEEE transactions on nuclear science, Vol.60, N°.5, October 13.[5] G. Laffont, R. Cotillard and P. Ferdinand, Multiplexed regenerated Fiber Bragg Gratings for high temperature measurement, Measurement Science and Technology, Vol. 24, N° 9, 24, 2013[6] G. Laffont, R. Cotillard and P. Ferdinand, “9000 hours-long high temperature annealing of regenerated fibre Bragg gratings”, 5th European Workshop on Optical Fibre Sensors, Krakow, Poland,May 19-22, 2013[7] NEEDS French Research Framework – « Nuclear, Energy, Environment, Waste and Society” http://www.cnrs.fr/mi/spip.php?article19[8] J.-C. Bosq, M. Antony, J. Di Salvo, J.-C. Klein, N. Thiollay, P. Blaise, P. Leconte., “The Use of EOLE and MINERVE Critical Facilities for the Generation 3 Light Water Reactor Studies”, Proc. Int. Conf. ICAPP, Nice, May 2-5, 2011

International audience; In the framework of the development by CEA and SCK•CEN of a Fabry Perot Sensor (FPS) able to measure dimensional changes in Material Testing Reactor (MTR), the first goal of the SAKE 1 irradiation was to measure the linear compaction of single mode fibres under high fast neutronfluence. Indeed, the compaction of the fiber which forms one side of the Fabry Perot cavity in the modified sensor design [1], may generate a noticeable measurement error. Primak [2] measured 1% compaction for bulk silica after 2×1019 nfast/cm². An accurate measurement of the linear compaction of the fibre optic associated with the sensor operation in MTR will permit to predict the radiation-induced drift and optimize its design.In the SAKE1 experiment approximately fifty uncoated fibre tips (length: 30 to 50 mm) prepared using several different fiber types have been set in three different capsules, which were exposed in the SCK•CEN BR2 reactor (Mol Belgium). The irradiation lasted 22 days leading to a total fast (E > 1MeV) fluence of 3 to 5×1019 nfast/cm², depending on the capsule. The temperature during irradiation was 291°C, which corresponds to the condition of the intended FPS use. A precise measurement of each fiber tip length was made before the irradiation and compared to the post irradiation measurement highlighting a decrease of the fibres' length.The results of the length measurements will be presented. With a good precision, they give around 0.25% of linear compaction for the fibres used to make the FPS. The scale of the changes is independent on the capsule, which means that the effect saturated even at the lowest dose.In the prospect of performing distributed temperature measurement in MTR, some Bragg gratings have been irradiated in the same capsules. Four gratings were provided by the University of Mons, Belgium and four others were made by the LabHC. All the gratings were written in radiation tolerantfibres, but those from Saint-Etienne underwent an additional treatment with a procedure enhancing their radiation resistance to ionizing radiations [3,4].We have made a special mounting allowing to test the reflexion and the transmission of the gratings on fibre samples cut down to 30 to 50 mm. The comparison of measurements made before and after the irradiation, at the same temperature, allowed to measure the loss in reflection as well as the Bragg wavelength drift. The results will be presented; they are quite promising for some of the investigated gratings.[1] G. Cheymol, A. Gusarov, S. Gaillot, C. Destouches and N. Caron, « Dimensional Measurements Under High Radiation With Optical Fibre Sensors Based on White Light Interferometry - Report on Irradiation Tests"; Nuclear Science, IEEE Transactions on (Volume:61 , Issue: 4 )[2] W.Primak, "Fast neutron induced changes in quartz and vitreous silica", Phys. Rev.B 110(6), 1240-1254 (1958)[3] A. Morana, S. Girard, E. Marin, C. Marcandella, P. Paillet, J. Périsse, J.-R. Macé, A. Boukenter, M.Cannas and Y. Ouerdane, "Radiation tolerant fiber Bragg gratings for high temperature monitoring at MGy dose levels", Optics Letters, Vol. 39, No. 18, September 15, 2014[4] AREVA-LabHC pending patent, "Procédé de fabrication d'une fibre optique traitée pour capteur de température résistant aux radiations", deposited Dec. 16th 2013, n°13 62691

Observations of torsades de pointes during therapy with terfenadine and astemizole has raised concern about the cardiac safety of non-sedating H1-antagonist agents. We compared cetirizine, another compound of that class, to D-sotalol and to astemizole in a model of acquired long QT syndrome. Open-chest surgery was performed in adult beagle dogs anaesthetized with halothane and thiopental. Bradycardia was produced with beta-adrenergic blockade and sinus node crush. Four left ventricular intramyocardial unipolar monophasic action potentials (MAP) were recorded during atrial pacing at basic cycle lengths (BCL) 400-1500 msec, before and during three successive 1-h drug infusions (0.14, 0.45 and 1.4 mg/kg/h for astemizole and cetirizine and 1.1, 2.2 and 4.5 mg/kg/h for D-sotalol). Dose- and bradycardia-dependent prolongations of MAP duration (MAPD) were produced by D-sotalol (P < 0.001) and astemizole (P < 0.001) but not by cetirizine. At BCL 1500 ms, the three infusions of astemizole prolonged endocardial MAPD from 323 +/- 8 msec (mean +/- SE) at baseline to 343 +/- 10, 379 +/- 13 and 468 +/- 26 msec, respectively (n = 9). Sotalol prolonged that MAPD from 339 +/- 6 msec to 377 +/- 7, 444 +/- 15 and 485 +/- 24 msec (n = 7). In contrast, cetirizine did not prolong MAPD: 341 +/- 8 msec at baseline Vs 330 +/- 8, 324 +/- 9 and 323 +/- 11 msec (n = 9). Drug-induced increase in transmural dispersion reached +79 +/- 19 msec after astemizole, +59 +/- 21 msec after D-sotalol and only +7 +/- 11 msec after cetirizine. Runs of ventricular tachycardias and torsades de pointes occurred during dose three of astemizole (5/9 dogs) and D-sotalol (4/7 dogs) but never during cetirizine. In the present model, astemizole and D-sotalol but not cetirizine prolonged MAPD and transmural dispersions of repolarization and produced torsades de pointes. These results suggest that the halothane-anaesthetized bradycardic dog could be a valuable model to discriminate drugs for their class III effects and proarrhythmic potencies.

The pharmacokinetics of dexfenfluramine (d-F) and its metabolite dexnorfenfluramine (d-NF) were compared in 10 obese (145 +/- 13 s.d. % of ideal body weight (IBW)) and 10 non-obese healthy volunteers (93 +/- 8% IBW). Each group included five men and five women, aged 28 +/- 8 years. Subjects were given single doses of d-F i.v. (15.5 mg base infused over 3 h) and orally (25.9 mg base in capsules) on separate occasions. After i.v. infusion in obese subjects, the volume of distribution (Vss) of d-F was significantly higher (969.7 +/- 393.3 l; 95% CI 688.6-1250 l) than in controls (668.7 +/- 139.6 l; 95% CI 568.9-768.5 l; P < 0.01). Clearance was not significantly different (43.9 +/- 21.0 l h-1 vs 37.3 +/- 10.6 l h-1) and the terminal half-life tended to be longer (17.8 +/- 9.4 vs 13.5 +/- 3.9 h NS). Combined data from the two groups indicated a positive correlation between Vss and % IBW (r = 0.544; P < 0.02). The oral bioavailability of d-F was 0.61 +/- 0.15 in obese subjects and 0.69 +/- 0.11 in controls. There was no significant difference between obese subjects and controls in Cmax, tmax and t1/2,z (Cmax: 20.1 +/- 6.7 and 27.3 +/- 6.2 micrograms l-1; tmax: 3.5 vs 3.0; t1/2,z: 16.5 +/- 7.1 vs 14.5 +/- 2.6 h respectively). The AUC ratio expressed in molar units for d-F/d-NF was 2.29 +/- 1.78 (i.v.) vs 1.25 +/- 0.64 (oral) in obese subjects and 2.05 +/- 1.26 (i.v.) vs 1.40 +/- 0.87 (oral) in controls.(ABSTRACT TRUNCATED AT 250 WORDS)