[en] In 1991, cracks were discovered and localized in the lower part of certain vessel head adapters in EDF PWR units. While awaiting the replacement of the vessel heads in question, EDF developed systems to enable continuous monitoring of vessel head penetration, by means of early detection of leaks. One of these systems in based on detection of water vapour in a confined space above the vessel head. The efficiency of the measurement chain is particularly dependent on dilution of the leakage in the confined space prior TO entry in the sampling circuit. The detection threshold for this method is on the order of 1.2 liters/hour for a dilution rate of 1500 rate of 1500 m³/h and a dew point of 22 deg C. This system has now been in operation on three 1300-MW PWR units for three years, and has proved to function satisfactorily. (authors)

[en] This paper analyses the main problems involved in open cooling circuit of nuclear power stations, for both seaside and riverside sites. Taking into consideration these developments, it describes the means - and notably the models - used to study many aspects of these questions

[en] BUGEY-3 feedback and mechanical analyses have both shown the possibility of leaks through alloy 600 penetration cracks. At the beginning of 1993, at least 4% of the 1000 inspected penetrations on French pressurized water reactors (PWRs) demonstrated evidence of purely longitudinal cracks at various stages of evolution. This relatively new problem is a major problem for Electricite de France (EdF) because approximately four points of PWR availability were lost in 1992. Although cracking is not considered by EdF as presenting near-term risks for safety, EdF's strategy heavily relies on efficient leak-detection devices. A couple of days after the BUGEY-3 leak discovery, in October 1991, EdF started testing or at least carrying out investigations on a number of various devices to set up an industrial device for reliable and efficient leak-detection systems

[en] We present an overview of recent experiments fielded on the LIL facility. A key issue for mega-joule class laser facilities is shrapnel fragment generation. A specific collector was therefore developed to capture debris in aerogel and dedicated shots were done to quantitatively evaluate target fragmentation phenomena. The LIL panel of transmitted and backscattered light diagnostics is well suited for laser-plasma interaction (LPI) experiments. This include gas-filled hohlraum configurations relevant to Indirect Drive ignition targets in order to test the specific LMJ longitudinal SSD technique, as well as LPI experiments with foam targets for laser beam smoothing in underdense plasma in the context of Direct Drive. After Visar commissioning a campaign was dedicated to boron Equation of State (EOS).

[en] The Ligne d'Integration Laser (LIL) facility has been designed as a prototype for the Laser MegaJoule (LMJ) which is a cornerstone of the French 'Simulation Program'. This laser has been intensively used to test and improve the LMJ components. In addition, a large panel of plasma diagnostics has been installed and is currently used to perform laser-plasma experiments. After a brief discussion about the LIL design, we present the last results in various plasma physics domains.