International Conference on Management of Spent Fuel from Nuclear Power Reactors, Vienna, 31 May - 4 June 2010 Anibal Barrera Life Extension Project Embalse NPP. Operating Experience and Condition Assessment of Spent Fuel Dry Storage Silos and Spent Fuel Pool at Embalse NPP
Spent Fuel Dry Storage Silos at Embalse NPP In Service Inspection Program (ISI) Condition Assessment ◦ Degradation mechanism ◦ Evaluation procedures Conclusions and future tasks Spent Fuel Pool CONTENTS
Design – Mock up 248 SILOS Fuel Bundles 2013 – Refurbishment Outage Spent Fuel Dry Storage Silos at Embalse NPP
Concrete Type II Portland cement f`c = 21 MPa Density = 2400 kg/m 3 Reinforcement Fy = 420 MPa (Grade 60) Steel Liner F 26 (ASTM A -36) Spent Fuel Dry Storage Silos at Embalse NPP
Internal Moisture – Pressure air cleaning Carbon Steel Corrosion Aerosols and noble gases detection External Radiation Monitoring Containment Barrier Integrity X-rays surface examination – contact dose rate Visual inspection, Corrosion analysis and thickness measurement Mock up with baskets and metallic samples In Service Inspection Program (ISI)
MechanismMaterialManifestationE. Procedure Sulphate attack Concrete Volume Change/ Cracking Visual Insp – Petrographic A. Carbonation Concrete Carbon Steel Vulnerable to corrosion Petrographic A Carbonation depth m. Cement- Aggregate reaction Concrete Volume Change / Cracking Visual Insp – Petrographic A. Thermal Exposure Concrete Cracking / Spalling Visual Insp – Petrographic A. Irradiation Concrete /C. steel Volume Change/ Cracking Petrographic A. Shrinkage Concrete Volume Change/ Cracking Visual Insp. Corrosion C. Steel Concrete Cracking – Section/capacity loss Visual Insp. – Electrical potential measurement Degradation mechanism - Evaluation procedures
ISI tasks Steel Corrosion New ISI Program ◦ Periodic Visual inspection Crack Survey ◦ Non destructive testing Ultrasonic P.V. ◦ Destructive Testing c. quality – calibration NDT – Petrographic examination Conclusions
SPENT FUEL POOL
CONCRETE 1 - Amercoat90 (6 mil) 2 - Amercoat90 (6 mil) 3 - Amercoat mm (6 mil) 4 - Fiber-Glass Cloth with Amercoat mm (~9 mil) 5 - Sand Filled Epoxy Grout mm (62.5 – 125 mil) LINER SYSTEM
No evidence of sign of leakage in external surfaces. No evidence of leakage in the Spent fuel Pool Under drainage System Bubbles in liner were found – Temperature and irradiation PREVENTIVE MAINTENANCE EPOXY UNDERWATER COATING SUMMARY
Thank you for your attention!