TPM-B - Special Session: Remediation of Contaminated Sites Centennial Ballroom 300B 13:30 - 17:30
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| Chair(s): Jeff Whicker, Lisa Manglass
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TPM-B.1
13:30 Adaptive Management of Radioactively Contaminated Sites JW Whicker*, Independent Consultant
Abstract: Effective responses to releases of radioactive material into the environment limit human and environmental harm, effectively restore land use, and maintain public confidence. Though we learned from past releases, each had unique technical, economic, social, and political challenges that defy generalizations. While all nuclear facilities have emergency response plans, in actual releases, critical information for quantitative risk assessment and effective restoration must be anticipated to be incomplete and uncertain. Whereas present planning documents have substantial linearity in their organization, the “adaptive management” paradigm provides a constructive parallel paradigm that anticipates and plans for uncertainty, inefficiencies, and stakeholder participation. Adaptive management grew out of the need to manage and restore natural resources in highly complex and changing environments with limited knowledge about causal relationships and responses to restoration actions. Explicit integration of adaptive management principles into restoration processes will result in substantially enhanced and flexible responses.
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TPM-B.2
14:00 Implementing As Low As Reasonably Achievable to Performance Assessments using Structured Decision Making and Decision Analysis PK Black*, Neptune and Company, Inc.
; TB Stockton, Neptune and Company, Inc.; RA Perona, Neptune and Company, Inc.; KM Catlett, Neptune and Company, Inc.
Abstract: The As Low As Reasonably Achievable mandate requires optimization across social, technical, economic, practical, and public policy aspects of radiological risk decisions. An analysis that includes these concepts can be aligned with a values-based approach to decision making. This presentation will explore and provide examples of Structured Decision Making as a rigorous decision science-based framework for conducting a quantitative ALARA analysis for radiological risk assessments. Advantages of this approach include effective stakeholder engagement, placing science models in the context of the decision model, and optimizing decisions. In effect, SDM provides a framework that initializes the decision-making process based on the concept that “we are making a decision because someone cares about something, perhaps we should find out what they care about first”. Structured Decision Making fully integrates science and values-focused thinking to arrive at the optimal solution, meeting the intent of ALARA, and leading towards more effective cost/benefit decision-making
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TPM-B.3
14:30 Retrospective Detection Sensitivity for GPS-Based Gamma Radiation Surveys TJ Alecksen*, Environmental Restoration Group, Inc.
; RD Whicker, Environmental Restoration Group, Inc.
Abstract: Since the publication of the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) (NRC, 2000), use of global positioning systems (GPS)-based gamma radiation survey (gamma survey) techniques has become prevalent for characterizing radiological soil contamination in outdoor environments. These systems automatically record gamma radiation levels with thallium-doped sodium iodide NaI(Tl) scintillation instruments (NaI detectors) and corresponding geospatial coordinates with GPS receivers. Determination of the minimum detectable concentration (MDC) of a contaminant radionuclide in soil while scanning (scan MDC) with GPS-based gamma survey systems requires consideration of changes in detection efficiency as the NaI detector passes over a source of such contamination. A method called the “probabilistic method” was developed to calculate the a priori scan MDC for a single observation interval of a GPS-based gamma survey system when considering numerous survey parameters such as detector size, scan height, scan speed, and various source specifications.
Due to the nature of GPS-based gamma surveys, collected data often consists of high-density spatial groupings of individual measurements. When considering a macroscopic analysis of an entire group of data, rather than a single observation, additional metrics may be applied to quantify detection sensitivity. This presentation discusses the quantification of the minimum detectable count rate (MDCR) as described in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) and scanning MDC when applied to large populations of spatially correlated gamma data. The use of Nearest Neighbor averaging of the grouped measurements provides further retrospective quantification of MDCR values and shows evidence of improving the sensitivity of a posteriori analysis.
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TPM-B.4
15:00 Radiological Clearance of Property at DOE-EM Sites AL Anderson*, US Department of Energy
Abstract: The regulatory framework for radiological clearance activities for US Department of Energy sites are established for clearance of real and personal property. In 2021 the Office of Environmental Protection and ESH Reporting authorized the use of the volumetric clearance criteria from the national consensus standard, ANSI N13.12-2013, Surface and Volume Radioactive Standards for Clearance, for certain situations. An Operating Level 3 (OE-3) document was also issued describing the Implementation of Pre-approved Authorized Limits for the Release and Clearance of Volumetric Radioactivity of Personal Property at DOE Field Elements. The Acting Assistant Secretary for Environment Management (EM) issued additional guidance for EM sites noting specific limitations for the use of the ANSI N13.12-2013 volumetric values related to recycle and the metals moratorium. This presentation will discuss the guidance for the release and clearance of property from DOE EM sites.
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TPM-B.5
15:30 Break
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TPM-B.6
16:00 NRC Decommissioning Research and Related Guidance Development CS Barr*, US NRC
; T Aird, US NRC
Abstract: NRC is updating its decommissioning guidance based on lessons learned from recent reviews of decommissioning plans, license termination plans, and final status surveys. NRC has also worked with federal partners on the second revision to the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) to update guidance on radiological surveys to demonstrate compliance with release criteria. NRC is still working on guidance in two key areas: subsurface investigations and discrete radioactive particles (DRPs).
The guidance on subsurface investigations focuses on the soils, deep subsurface structures, and groundwater at sites undergoing decommissioning. As part of developing the relevant technical basis for guidance on subsurface investigations, research has focused on demonstrating proposed survey design optimization methods as well as data analysis techniques. Recommendations are also being formulated for software development to provide tools to help implement the proposed methodologies. The technical basis document will be considered in developing interim guidance with the objective of improving the radiological survey and site investigation process to better assess and manage risks associated with subsurface soils, building materials, and groundwater. Stakeholder engagement is actively being sought on this guidance topic. A public workshop was held in July 2021 and a follow-on meeting is planned for May 2022.
NRC is also evaluating the need for additional guidance or communications related to DRPs. Lessons learned from recent reactor decommissioning reviews, including radiological survey performance and dose modeling considerations are being considered. NRC plans to seek public engagement on this guidance topic with potential public meetings to be held later in 2022.
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TPM-B.7
16:30 Update on Revisions to the Multi-Agency Radiation Survey and Site Investigation Manual DO Stuenkel*, U.S. Environmental Protection Agency
; AL Anderson, U.S. Department of Energy
Abstract: The Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) is an interagency document that provides information on planning, conducting, evaluating, and documenting environmental radiological surveys of surface soil and building surfaces for demonstrating compliance with radiation dose- or risk-based regulations. The MARSSIM Workgroup includes representatives from the Department of Defense (DoD), Department of Energy (DOE), Environmental Protection Agency (EPA), and Nuclear Regulatory Commission (NRC). MARSSIM was first published in 1997 and subsequently revised in 2000. The MARSSIM Workgroup drafted Revision 2 to incorporate significant changes in science and technology, provide additional guidance for sites on “indistinguishable from background” situations, and improve the understandability of the document. In 2020, a draft of Revision 2 was reviewed by EPA’s Scientific Advisory Board -Radiation Advisory Committee (SAB-RAC) and made available for public comment. The SAB-RAC provided a draft report of its review in November 2021. This presentation includes a summary of the proposed changes to be included in Revision 2 and the results of the SAB and public reviews.
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TPM-B.8
17:00 Business Meeting
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