Open Access
Table 1
Comparison between the cold and the warm roof slab
| Cold roof slab | Warm roof slab | |
|---|---|---|
| Advantages | – Reduction of thermal expansions of the bottom plate – Reduction of uncertainty of horizontal locations of ACS – Reduction of temperatures of seals, concretes and electrical devices – NPP availability (shorter shutdown) – No restricted access to the roof slab due to temperature during normal operation |
– Reduction of thermosiphons effects along components penetrations – Reduction of risk of Na deposit in components penetrations – Reduction of thermal power to evacuate through cooling system: allow to replace complex thermal insulation (Na compatible) by a simple baffle – Reduction of thermal stress within structures |
| Drawbacks | – Cost – Increment of thermal insulation and of roof slab total height – Impact of the active gas cooling system on the reactor building – Increment of the risk of thermosiphons effects along components penetrations – Risk of Na deposit in component penetrations and impossible removal of components for maintenance/ renewal – Increment of thermal gradients within structures (including the main vessel and components) |
– Reduction of seals lifetime – Limitation of tightness performances of seals on the roof slab during accident (due to higher temperatures) – Height of the cylindrical skirt that supports the roof slab and the main vessel – Reduction of NPP availability due to cooldown transients before shutdown and heating transients before start – Needs of thermal insulation on top of the roof slab – Higher temperature of electrical devices – Increment of uncertainty of horizontal locations of ACS – Resistance of concrete to higher temperatures |
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.