Carlos Tapia

Development and assessment of fire-related risk unavailability matrices to support the application of the maintenance rule in a PWR nuclear power plant

ABSTRACT Two methods are presented which serve to incorporate the fire-related risk into the current practices in nuclear power plants with respect to the assessment of configurations. The development of these methods is restricted to the compulsory use of fire probabilistic safety assessment (PSA) models. The first method is a fire protection systems and key safety functions unavailability matrix which is developed to identify structures, systems, and components significant for fire-related risk. The second method is a fire zones and key safety functions (KSFs) fire risk matrix which is useful to identify fire zones which are candidates for risk management actions. Specific selection and quantification methodologies have been developed to obtain the matrices. The Monte Carlo method has been used to assess the uncertainty of the unavailability matrix. The analysis shows that the uncertainty is sufficiently bounded. The significant fire-related risk is localized in six KSF representative components and one fire protection system which should be included in the maintenance rule. The unavailability of fire protection systems does not significantly affect the risk. The fire risk matrix identifies the fire zones that contribute the most to the fire-related risk. These zones belong to the control building and electric penetrations building.

A new code for spectrometric analysis for environmental radiological surveillance on monitors focused on gamma radioactivity on aerosols

This paper presents a new code for the analysis of gamma spectra generated by an equipment for continuous measurement and identification of gamma radioactivity in aerosols with paper filter. It is called pGamma and has been developed by the NERG group at the Technical University of Catalonia - Barcelona Tech and Raditel Serveis i Subministraments Tec-nològics, Ltd. The code is being adapted to the monitors of the Environmental Radiological Surveillance Network of the Gener-alitat de Catalunya (local Catalan Government), Spain. The code is a spectrum analysis system for identifying and determining activity concentration of gamma emitters. It generates alarms depending on the activity of emitters and then elaborates reports. Moreover, it includes a library with NORM and artificial emitters of interest. The code is being used at three stations of the Network equipped with an aerosol monitor (Ascó and Vandellòs (province of Tarragona)and Barcelona).

Equipment for the Continuous Measurement and Identification of Gamma Radioactivity on Aerosols

This paper describes an equipment for continuous measurement and identification of gamma radioactivity in aerosols developed by the Nuclear Engineering Research Group (NERG) at the Technical University of Catalonia (UPC) and Raditel Serveis i Subministraments Tecnològics, Ltd. A spectrometric analysis code has been specially designed for it. Spectrum analysis identifies and determines activity concentration of aerosol emitters captured by a fiberglass paper filter. This new equipment is currently operating in three radioactivity monitoring stations of the Environmental Radiological Surveillance Network of the Generalitat of Catalunya (local Catalan government): two near Ascó and Vandellòs Nuclear Power Plants in the province of Tarragona and one in the city of Barcelona. Two more monitors are expected to be deployed at Roses (province of Girona) and Puigcerdà (province of Barcelona). Measurements and evolution analysis results of emitters identified at these stations were also provided.