In English

RELAP5 to TRACE model conversion for a Pressurized Water Reactor

Federico López-Cerón Nieto
Göteborg : Chalmers tekniska högskola, 2017. 56 s.
[Examensarbete på avancerad nivå]

Safety is an important concern in Nuclear Power Plants because of large radioactive inventory produced during operations. Therefore, an accurate analysis of the system under normal and accidental conditions is necessary and relies on the use of complex computational capabilities. In particular, thermal-hydraulic system codes such as RELAP5 and TRACE can be applied to study the cooling of a reactor core under a variety of possible scenarios (e.g., in the case of a loss of coolant accident). The focus of the current thesis is on the development of a TRACE model for a Pressurized Water Reactor. Such a model is derived from an existing RELAP5 model that was built at the Universitat Politecnica de Valencia (UPV). The procedure consists of an automatic conversion by applying the software SNAP. Following the automatic conversion, an extensive post-processing is needed to correct possible bugs and improve the new model. In addition, a second TRACE input deck is created, where a special component available in TRACE is used for the reactor core region, namely the VESSEL component. Different types of calculations are performed with the two new TRACE models and with the RELAP5 model, so that the correctness of the TRACE models can be verified. First, steady-state and transient simulations using only TRACE and RELAP5, are run. Then, since in Pressurized Water Reactors there is a strong coupling between the coolant conditions and the reactor power, calculations based on the coupling of TRACE and RELAP5 to the 3-D neutronic core simulator PARCS, were also considered. The analysis shows that the RELAP5 model and the TRACE model without the VESSEL component lead to similar results. On the other hand, the TRACE model with the VESSEL component, which consists of only a single channel for the reactor core region, requires further refinements.

Publikationen registrerades 2017-02-03. Den ändrades senast 2017-02-03

CPL ID: 247990

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