Introduction

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INSIDER Data analysis & sampling design strategy

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The EURATOM work programme project INSIDER (Improved Nuclear SIte characterization for waste minimization in Decommissioning under constrained EnviRonment) was launched in June 2017. It aims at improving the management of contaminated materials arising from decommissioning and dismantling (D&D) operations by proposing an integrated methodology of characterization. The methodology is based on proper statistical data analysis and sampling design, coupled with adapted and innovative measurement techniques, in line with sustainability and economic objectives. The main objective of Work Package 3 (WP3) is to draft a strategy for data analysis and sampling design for initial nuclear site characterization in constraint environments before decommissioning, based on a statistical approach. This is done by selecting state-of-the-art techniques concerning data analysis and sampling design, using prior information and multiple iterations, testing the approach through different case studies and reviewing the feedback from overall uncertainty calculations. The process followed to meet the main WP3 objective consists of four steps:

  1. Status: Provide an overview of the available sampling design methods and state-of-the-art statistical techniques.
  2. Development: Develop a strategy for data analysis and sampling design, referring to state-of-the-art techniques, and provide guidance to the end user through an application in which the strategy contents can be explored in a user-friendly way.
  3. Implementation: Follow the strategy when working out the methodology for the different test cases, in order to test its adequacy and identify potential flaws.
  4. Guidance: Summarize all the findings in a comprehensive data analysis and sampling design strategy guide.

The first step was tackled in the first task of WP3, and resulted in a first document (Deliverable D3.1, Pérot et al. 2018) that provides an overview on sampling design methods and state-of-the-art statistical techniques for preliminary analyses and data processing. The second step is the development of a strategy for sampling in the field of initial nuclear site characterization in view of decommissioning, with the most important goal to guide the end user to appropriate statistical methods and approaches to use for data analysis and sampling design. This includes, but is not necessarily limited to the methods listed by Pérot et al. (2018). For specific cases that might have been overlooked and that are now revealed by structuring potential questions and situations, other methods can be referred to as well. This tool provides an overview of the developed data analysis and sampling design strategy. All the different steps to take are described in a way that should be sufficient for the end user to make well-founded decisions. To aid the end user in applying the proposed strategy, this application is presenting the different strategies in a user-friendly way. Similar to the work of Pérot et al. (2018), this tool is not aimed at providing an overview of all the existing statistical methods or guidelines to the end user. It rather tries to point the end user to methods that can be applied in specific situations and for specific goals, while highlighting the different assumptions and limitations. As the list of possible situations and goals is extensive, we try to provide a structured way for the end user to determine what type of situation is at hand, and which corresponding methods can be applied. By no means have we attempted to provide an exhaustive list here, we just try to cover most potential practical applications in the field of initial nuclear site characterization with at least a few options. Other methods and/or approaches might be of equal use and reliability, when handled with sufficient expertise. The latter is of course also required when applying the methods discussed here. Note also that this strategy might be superseded by later work within WP3, as it will be thoroughly reviewed and tested in practice during the third step in reaching the main WP3 objective. The proposed strategy is structured here by using different diagrams, of which an overview is provided in Figure 1. We first discuss the overall strategy or generic workflow, outlining the general steps between a request for initial characterization and reporting of the final results, after all objectives have been reached. Afterwards, we go through the different steps related to the actual data analysis and sampling design. Following the outlining of the strategy, we list the main methods for data analysis and for sampling design. We only provide concise descriptions here, and try to list relevant theoretical references, case studies and software implementations for helping the end user to get started. We finally provide some thoughts on how the strategy should be applied in practice as well as a brief conclusion and outlook on the review and testing later on within WP3.

Overall strategy

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Data analysis & sampling design

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List of methods for data analysis

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