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!