Flow Accelerated Corrosion mitigation at EDF with
BRT-CICERO^TM.
Feedback of version 3 and process of validation.

Authors : S. Trévin¹, M. Persoz¹, C. Chevrier¹
                 L. Dejoux²
                 C. Miller²

Company : ¹ EDF/DPIH/DTG
                   ² EDF/DPN/UNIE
                   ³ EDF/DIN/CEIDRE

Country : France

Topics :

FAC Prediction tools
Experience Feedback
PWR
Carbon steel
Balance of Plant
BRT-CICERO^TM

ABSTRACT :

Flow accelerated corrosion calculations on EDF NPP's piping.

EDF has developed during these 15 last years a software called BRT-CICERO^TM for the surveillance of the secondary piping system of its Pressurized Water Reactors (PWRs). This software enables the operator to calculate the FAC wear rates taking into account all the influencing parameters such as : pipe isometrics, chromium content of the steel, chemical conditioning and operating parameters of the secondary circuit (temperature, pressure, etc.). This is a major tool for the operators to organize the maintenance and to plan the inspections.

In the framework of the French pressure vessel law issued on March 15th 2000, the software BRT-CICERO^TM has been recognized by the French authority for the FAC surveillance on the secondary pressure piping lines of the EDF 58 NPPs. It takes advantage of the experience feedback of the French fleet, of the R&D improvements (especially from the laboratory tests conducted on EDF's CIROCO loop) and is frequently updated. 

Improvement of the new version

In 2005, EDF/DPN decided to update BRT-CICERO^TM in order to take into account the experience feedback, like the last algorithm for thermodynamical calculations and to improve the consideration of the disruptive hydraulic effects along the pipes. The version 3 uses computer tools that are consistent with update operating systems (MS Windows 2000, XP and Vista) and the developments respect precise rules of validation and verification.

The software is based on specific calculation modules, which are :

• thermodynamics module,
• chemistry module,
• void module,
• geometric factor module to take into account the effect of singularities on hydraulics,
• FAC kinetics module,
• codes and standards module for minimum required thickness calculations.

This architecture allows independent and complete validation of each model calculation and therefore the quality of software.

This paper describes

• the model and the calculations released by BRT-CICERO^TM version 3,
• the validation of the version 3 through the update of the version 2 database and the comparison of the predictions of the version 2 and version 3 for each NPP,
• the validation of the version 3 through the comparison between residual thickness predictions and thickness measurements using more than 15 000 results of inspections on the French fleet.
• The futures developments of BRT-CICERO^TM.