Análisis termohidráulico de la instalación LSTF/ROSA utilizando el código TRACE5. Aportaciones a la metodología de escalado
[EN] The origin of the scaling-issue is the impossibility to obtain measured data in case of an accident in nuclear reactors. The knowledge of thermal hydraulic phenomena oc-curring in Nuclear Power Plants (NPP) during an accident is very important in nuclear safety. As full-scale testing is usually...
| Author: | |
|---|---|
| Format: | doctoral thesis |
| Publication Date: | 2015 |
| Country: | España |
| Institution: | Universitat Politècnica de València (UPV) |
| Repository: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Language: | Spanish |
| OAI Identifier: | oai:riunet.upv.es:10251/59445 |
| Online Access: | https://riunet.upv.es/handle/10251/59445 |
| Access Level: | Open access |
| Keyword: | TRACE5 LSTF PKL PWR Termohidráulica INGENIERIA NUCLEAR |
| Summary: | [EN] The origin of the scaling-issue is the impossibility to obtain measured data in case of an accident in nuclear reactors. The knowledge of thermal hydraulic phenomena oc-curring in Nuclear Power Plants (NPP) during an accident is very important in nuclear safety. As full-scale testing is usually impossible to perform it, thus, a number of small-scale Integral Test Facilities (ITF) of prototype systems have been built to inves-tigate the physical phenomena of transients or possible accidents in NPPs. The design and implementation of these small-scale ITF is performed in the frame of several international projects, among which are the promoted by the Nuclear Safety Council (CSN) and the Organization for Economic Cooperation and Development (OECD) aimed at assimilation, application and improvement of thermalhydraulic codes. Among them, the projects "Analysis and simulation of accidental sequences in PWR reactors. SPAIN CAMP Project" and "Analysis and simulation of the OECD/NEA PKL and OECD/NEA ROSA experiments. Application to the Spanish NPP" are based on a series of experiments in Large Scale Test Facility (LSTF) and Primärkreislauf Versuchsanlage (PKL), both ITF. To analyze the applicability and/or extension of these results to the safety and opera-tion of a generic NPP in this Thesis a methodology applied to the scaling has been developed. This methodology consists of the following points. First, a LSTF model has been developed using the thermalhydraulic code TRACE (TRAC / RELAP Advanced Computational Engine). This model has been used to reproduce different experiments based on Small Break Loss-Of-Coolant Accident (SBLOCA) produced in different locations of the ITF (upper head of the vessel, hot legs, cold legs, etc.). After comparing the simulation results with experimental ones, the differences between both have been analyzed. Furthermore, the special TRACE5 models have been considered to improve the simulation of determined phenomena. With this, a validated LSTF model developed using TRACE5 has been obtained. From the LSTF model, a scaled-up model has been developed applying the volumetric scaling methodology. The use of this methodology is based on the LSTF is a Full-Height, Full- Pressure (FHFP) facility and all the accidents considered are SBLOCA. Under these conditions, the fluid properties are maintained; therefore, it is appropriate to use the volumetric scaling methodology. The same experiments reproduced using the LSTF model have been simulated with the scaled-up model to assess if TRACE5 code is able to well reproduce the same phe-nomenology happening in a small scale facility. The simulation results have been compared with experimental results and those obtained with the LSTF model. Furthermore, trying to study in depth the scaling methodology, a TRACE5 model of the PKL facility has been used to reproduce the counterpart test, which is common to LSTF and PKL facilities. These facilities are not equal in design and operation condi-tions. It allows studying the phenomenology and scaling aspects in systems with dif-ferent design and operation conditions as well as to obtain scaling relations between both facilities. |
|---|