DISCOMS: DIstributed Sensing for COrium Monitoring and Safety

DISCOMS : Capteurs Répartis pour le surveillance du corium et la sûreté

Pierre Ferdinand (1) , Laurent Maurin (1) , Stéphane Rougeault (1) , Hamid Makil (2) , G. Cheymol (3) , H. Maskrot (3) , P. Le Tutour (4) , D. Duval (4) , Christophe Journeau (5) , J.-F Villard (5) , J-F Haquet (5) , Q. Souquet (5) , L. Barbot (5) , J. Miss (6) , I. Duhamel (6) , B. Dechenaux (6) , M. Brovchenko (6) , G. Musoyan (7) , S. Balleydier (7) , F. Pouillé (8) , G. Helleux (9) , S. Fourrez (9) , L. Pichon (9)

1 LCFO (CEA, LIST) - Laboratoire Capteurs Fibres Optiques (CEA, LIST)
2 LCAE (CEA, LIST) - Laboratoire Capteurs et Architectures Electroniques (CEA, LIST)
3 SEARS - Service d'études analytiques et de réactivité des surfaces
4 DPC - Département de Physico-Chimie
5 LEAG - Laboratoire d'Etudes et d'Expérimentation pour les Accidents Graves
6 IRSN - Institut de Radioprotection et de Sûreté Nucléaire
7 AREVA
8 LMP S.A. - Laboratoires Marie Pierre
9 THERMOCOAX SAS Company

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.

Mots clés: Nuclear safety; Corium Monitoring; Distributed sensing; Optical Fiber Sensor; SPND; instrumentation; nuclear instrumentation

Domaines: Sciences de l'ingénieur [physics]; Physique [physics]; Optique / photonique

Pierre Ferdinand, Laurent Maurin, Stéphane Rougeault, Hamid Makil, G. Cheymol, et al.. DISCOMS: DIstributed Sensing for COrium Monitoring and Safety. CANSMART 2015: International Conference on Smart Materials and Structures, Jul 2015, Vancouver, Canada. ⟨cea-02151741⟩