Project

Engineering Services and Support of QA: Application and enhancement of TRACE model. 

Support to scoping analyses for the extension of the emergency systems (ERNOS program)

Scope of the project

• Implementation of plant models (Main and GUI models) improvement in terms of ERNOS (Erweiterung der Notstand Systeme) capabilities, including additional inputs and optimizations. 
• Analysis of various IE (initiating events) with SBO (Station Blackout). 
• Analysis of various IE with SBO in combination with MSLB (main Steam Line Break). 
• Analysis of various LOCA (Loss-of-Coolant Accident) cases in combination with SBO. 

A spectrum of measures for management of the accident progression are considered. 

Expected output

• Assessment of the planned, automatic ERNOS algorithm for cooldown by ARV (Atmospheric Relief Valves) for the considered IE. 
• Assessment of late operator actions for accident management (90 min and 10 h after the accident onset) by switching ARV in cooldown mode with 10 K/h. 
• Assessment of operator actions for accident management by alignment of TA81,82 pumps for injection into the primary or spraying into PRZ (late actions are preferably considered). 
• Assessment of late operator actions for accident management by alignment of TH17,37 special emergency cool-down pumps for injection to the primary (90 min after IE onset). 
• Assessment of late operator actions for accident management by re-alignment of RX01 pump (special emergency feedwater pump) to RX02 tank (contains demineralized feedwater) when the level of RX01 tank is decreased to 0.5 m. 

Preliminary results can be found in Figure 12 ÷ Figure 14.