Chemical Decontamination Prior to Maintenance and Decommissioning

Abstract

Canadian Nuclear Laboratories (CNL) world class facilities and technical experts in chemical decontamination have extensive experience with reactor artefact characterization and with development, optimization and qualification of reactor decontamination processes. CNL’s services are backed by more than 50+ years of experience in the nuclear industry, during which time CNL established the technical and commercial expertise to handle numerous unique requirements. CNL (previously AECL) developed the CAN-DECON™¹ process, the first dilute regenerative process, in the late 1960’s. To solve issues specific to CANDU reactors, with their large carbon steel surface areas, the CAN-DEREM™² and CAN-DEREM Plus™³ processes were developed in the 1980’s and 1990’s. As the developers of these processes, CNL staff have participated in over 120 sub- and full system chemical decontaminations since the early 1970’s, providing services ranging from chemistry and material support to implementing full system decontaminations.

Atkins, a member of the SNC-Lavalin group, has a deep history in nuclear decommissioning and waste management that spans four continents and includes every stage of the nuclear fuel cycle from fuel manufacturing and reprocessing through commercial power generating facilities to disposition of cold war legacy sites. Atkins has a number of chemical decontamination processes that were developed and patented to serve the spent nuclear fuel reprocessing and fuel manufacturing business and the waste management process market. Of particular relevance to chemical decontamination is our provision of waste management services, specifically our liquid waste management technology and services. SNC-Lavalin routinely manage liquid waste and have delivered some very complex high source term projects such as managing the cooling water from the crippled Fukushima Daiichi reactors in Japan, processing the US DOE’s High Level Waste with our vitrification technology, supplying the liquid and solid waste management technology and equipment for the Haiyang AP 1000’s in China and serving the US LWR fleet liquid waste management needs.

With the emergent decommissioning of nuclear reactors has come a renewed need for chemical decontamination to achieve dose reduction and waste reclassification in order to drive down dose budgets for decommissioning projects. Additionally, increasingly stringent ALARA targets by plant operators is driving interest in chemical decontamination for maintenance activities at operational plants. This paper presents an overview of the application and importance of chemical decontamination of CANDU and LWR plants to achieve dose reduction for maintenance and decommissioning activities.