Papers by Nestor Masriera
The inclusion of a Cold Neutron Source (CNS) implies a major modification to a research reactor f... more The inclusion of a Cold Neutron Source (CNS) implies a major modification to a research reactor facility, and therefore would require issuing a revised version of the Safety Analysis Report (SAR) for its approval by the Regulatory Body. The support for successfully completing the licensing procedures should be considered part of the CNS supply, together with the design and provision of the CNS Facility itself. The nuclear safety of a CNS is strongly linked to the hydrogen hazard: a CNS has a large mass of a potentially explosive substance (namely hydrogen hereafter, be it hydrogen or deuterium), placed right by the reactor core. According to the international practice, the CNS Moderator Cell (boundary holding the liquid hydrogen) is surrounded by a Vacuum Containment that provides thermal insulation and a multiple barriers scheme to prevent hydrogen from mixing with water or air. This vessel should withstand any event, taking place in the CNS (including the hypothetical reaction sho...
International Journal of Nuclear Desalination, 2004
Although it is widely accepted that coupling a Desalination Plant (DP) to a Nuclear Power Plant (... more Although it is widely accepted that coupling a Desalination Plant (DP) to a Nuclear Power Plant (NPP) does not pose any significant additional hazard, it must clearly be considered as a major modification of the design and, therefore, requires issuing an ad hoc version of the Facility Safety Analysis Report (SAR). Documentation is already available covering general safety aspects of nuclear desalination, including standards and applicable requirements, as well as methodologies for assessing potential exposure. In this report, a specific analysis of the main features to be considered for producing the safety analysis report of a nuclear desalination plant will be presented. For the sake of clarity, it is assumed that there is an existing SAR of the NPP and only the additional information to be included in the SAR will be considered. The scope of this additional information is extremely dependent on the desalination technology and the coupling scheme. Therefore, the kind of nuclear desalination process coupling, i.e. thermal, mechanical or electrical, must be defined as a previous task. A thorough review of the main contents of the SAR is performed in order to identify the relevant points, if any, which need to be included in every chapter coping with the coupling. The SAR chapters' content and scope are considered in accordance with IAEA guidelines. As part of the safety report, possible accidental event analysis and their consequences must be included and, therefore, the deterministic analysis of an envelope case of contamination release through the DP must be assessed. The elaboration of this safety case is analysed, and the justified scope of the models needed to quantify the contamination transport mechanisms is presented. Finally, the most commonly accepted techniques and codes, used for the deterministic safety analysis of nuclear plants and effectively applicable to nuclear desalination plants, are presented by the use of the modelling tool DESNU.
International Journal of Nuclear Desalination, 2006
It is widely accepted that the general safety approach for nuclear facilities is valid for a Nucl... more It is widely accepted that the general safety approach for nuclear facilities is valid for a Nuclear Desalination Plant (NDP), thus IAEA standards and guides are applicable. The coupling of a NDP should be designed with the safety objective of ensuring that it results in no adverse effect on the Nuclear Power Plant (NPP) safety. The first objective (provisions of barriers) is complied with by the known NDP design, so the relevant issue becomes the design features preventing the transfer of radioactive material to the product water, even in the event of system failures. This presentation drafts a coupling-system safety assessment, from fundamentals and general requirements down to specific design requirements. The state of the art of monitoring systems imposes constraints on the coupling design, in terms of hold-up capability and piping interconnection. This conceptual design shows the system's complexity implied in having monitoring of product water as a safety feature, and conclusions are extremely relevant when drafting general user requirements for a NDP project.
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Papers by Nestor Masriera