Speaker
Description
The Fukushima accident highlighted the need to improve the design of the safety systems in order to cope the consequences of a full blackout accident. In particular, the decay heat removal function must always be ensured in order to guarantee the integrity of the first barrier and the second one confining the radioactivity. The paper shows the main features of the pre-design of an innovative ex-vessel Decay Heat Removal System (DHRS) designed for a SMR-SFR of a core power of 400 MWth. This safety system allows the heat removal in a fully passive way, only by the radiation of the outer surface of the primary vessel. The radiated heat is extracted by the DHRS through the enhanced natural circulation of a liquid metal flowing inside a bundle of tubes outside the vessel. The final heat sink of the DHRS is another important aspect of innovation. The aim is to diversify it, improving the safety function ensured by a standard water-cooled or air-cooled heat sink. For this purpose, the use of a Phase Change Material (PCM) has been chosen inside the heat sink in order to provide a supplementary thermal inertia, which contributes to improve the cooling capacity of the DHRS. Moreover, a PCM contributes to improve the compactness of the final heat sink, allowing its storage inside a dedicated building. This aspect allows this component to be protected by external aggressions, leading to a significant improvement the safety of the Nuclear Power Plant. The actual design of the ex-vessel DHRS has been applied to the new SFR sketch ATRIUM, in order to guarantee a fully passive cooling of the reactor core for a duration of three or more days.
| Speaker's email address | alessandro.pantano@cea.fr |
|---|---|
| Affiliation/Organization | CEA |
| Speaker's title | Mr |
| Country/Int. organization | France |
