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Bishop, Alexander Steven

Publications and source records attributed to Bishop, Alexander Steven.

Overview of SAVY-4000 Lifetime Extension Activities in Fiscal Year 2024

This report provides an overview of activities engaged in during the 2024 fiscal year in support of the SAVY-4000 (hereafter “SAVY”) lifetime extension. As the final full year prior to the submittal of the technical basis, efforts were made to assess the current understanding regarding SAVY degradation in service as well as any knowledge that provided a more substantive view of the challenges that SAVYs face in storage. Close coordination with the stakeholders (i.e. LANL program office) ensured alignment with expectations regarding timelines for the remainder of the activities supporting the technical basis document for the lifetime extension request.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Tools for Water Ingress Testing

The Safety Storage and Engineering Team, as part of the Production Support Services division (PSS-2), is tasked with ensuring the safety of containers used for handling and storage of nuclear materials. As part of this work, water ingress tests are conducted to evaluate the water-tightness of containers intended for in-glovebox use. In collaboration, the statistics group of the Computer and Computational Sciences Division (CCS-6) provided support in developing a statistically defensible approach for determining appropriate sample sizes for water ingress testing. Water ingress testing involves multiple measurements on multiple containers. Our approach uses a simple random effects model to analyze a pilot data set, implementing prediction limits to evaluate the efficacy of collecting additional data. Although this study capitalizes on available data, our approach can be used with estimates of the ratio of between and within variability and average values, often available from past testing or expert knowledge. An interactive Shiny tool was developed as a final user-friendly product for future testing. The Shiny interface is an open-source package providing a framework for building web applications. Raw data exploration and prediction interval-based sample size assessments can quickly be conducted by the engineering team without needing to interact with the underlying code.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

NMPWG Discussion on - Tracking Initial SAVY-4000 Population and Lifetime Extensions Across the DOE Complex [Slides]

As part of LANL's SAVY-4000 Lifetime Extension efforts, the question of "when does a SAVY's life start?" was posed. The unfortunate answer that can be agreed upon is to start the life based on the serial number which includes month and date of manufacture. For example - 012405025 was a 5QT container produced in January of 2024. This is not the most efficient way to track age of a container if extended lifetimes and usage are desired. Other possibilities include: Tracking on first-use date (date it was loaded); Tracking when it was sold from the warehouse to an operating group for use; Tracing the amount of time nuclear material is within the container (LANMAS transaction histories).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗