CANDU 6 Spent Fuel Pool Refurbishment

Abstract

First generation CANDU 6 Nuclear Power Plants (NPP) spent fuel pools were designed for the original NPP lifetime of 30 years. Throughout the years of operation, the epoxy liner covering the pool concrete walls have cracked and peeled, exposing the concrete to demineralized water and accelerating its degradation due to leaching of carbonate ions. In order to slow down this degradation and extend the lifetime of the pools, a refurbishment of the liner walls is required. A synthetic flexible liner made of multiple layers of an ethylene propylene diene monomer (EPDM) geomembrane, a geonet and geotextile (forming together a geocomposite) was developed, qualified for use in a highly radioactive environment and installed using mechanical fixtures. The life extension provided by this refurbishment enables the pools to stay in service long enough after definitive shutdown in order to properly plan for retrieving the various in-pools radioactive wastes for dry storage. This paper presents the project that was recently completed at our client’s nuclear power plant from the conceptual phase to installation of the leak-tight system at site. Our client wishes to remain confidential.