ML21180A135

U.S. Perspective on Developing Safety Cases for Various Radioactive Waste Disposal Facilities

ML21180A135
Person / Time
Issue date:	06/24/2021
From:	Chris Mckenney NRC/NMSS/DDUWP/PAB
To:
Chris McKenney, 301-415-6663
References
Download: ML21180A135 (15)

Text

U.S. Perspective on Developing NEA Expert Roundtable Safety Cases for Various Radioactive Waste Disposal June 24, 2021 Facilities Chris McKenney Risk and Technical Analysis Branch Division of Decommissioning, Uranium Recovery, and Waste Programs Office of Nuclear Material Safety and Safeguards

Major Considerations of a Near-Surface Safety Case Waste Hazard Considerations Role of Engineering for Short-lived (half-life <~30 years)

Radionuclides Utilization of Features, Events and Processes (FEPs)

Lessons Learned from Early U.S. Experience Human Inadvertent Intrusion Community Outreach Regulatory Oversight Considerations 2

Current U.S. Commercial US Ecology Low-Level Waste (LLW) Sites Hanford, Washington (1965)

All 4 sites regulated by Agreement States EnergySolutions Clive, Utah (1990) EnergySolutions Barnwell, South Carolina (1969)

Waste Control Specialists Andrews, Texas (2012) 3

Rough Comparison between IAEA and US NRC Waste Categories International Atomic Energy Agency Waste U.S. Waste Categories Categories High-Level Waste High-Level Waste Intermediate-Level Greater-than-Class C LLW Waste Low-Level Waste (LLW) Class A, Class B and C LLW Very Low-Level Waste Class A Material held for decay Very Short-Lived Waste storage Liquids/Air: Effluent releases Exempt Waste Solids: Case-by-case analysis 4

Wide Variety of Inventory

• Large scope of nuclear activities

• Wide variety of waste treatment Waste Hazard methods Considerations Waste Form

• Durability

• Impact on retention and release of radionuclides Waste Volume Mix of Radionuclides of Interest 5

Cell Operations at Waste Control Specialists, Andrews County, Texas 6

Most facilities rely on a combination of features to contain short-lived radionuclides, including:

Role of

• Site Characteristics Engineering

• Waste Form to Contain

• Disposal Cell Design Short-Lived

• Engineered Covers Radionuclides Concentrations in waste may be controlled by operational considerations 7

FEP Analysis coupled with Barrier Analysis is important in near-surface disposal FEPs Supports conceptual model development in Near-Surface Supported by early regulations (e.g., 10 CFR 61.12 requires specific technical information)

Disposal Hazard profile with time along with being in the biosphere leads to different primary FEPs (vs geologic disposal facilities) 8

Lessons Hydrology Issues Learned

• Water Retention in Disposal Cells ->

from Early Bathtubbing Experience

• Unidentified Fast Flow Groundwater Paths in the U.S. Waste Inventory Concerns for Near-

• Appropriate Concentration Limits Surface

• Waste Forms Performance

• Presence of Hazardous Material Issues

• Presence and Treatment of Liquids See NUREG-1853, History and Framework of Commercial Low-Level Radioactive Waste Management in the United States, https://www.nrc.gov/reading-rm/doc-9 collections/nuregs/staff/sr1853/index.html

Human Intrusion Scenarios Near surface more accessible for potential intrusion Loss of knowledge of sites still an issue with near surface disposal Larger variety of methods of disturbance 10

Human Intrusion 11

Most of the outreach managed by the licensee/developer/operator

• May establish citizen advisory panels Community

• Work with local organizations Outreach Regulators focus and

• Explaining regulations and allowing Involvement public comment

• Identifying hearing opportunities

• Discussing the decision-making process

• Announcing review findings and decisions 12

NRC

• Establishing generic regulations and guidance Regulatory

• Providing technical assistance, if requested by the State requests relationship

• Evaluate general approaches to new waste between streams

• Evaluate State programs for consistency U.S. Federal

• License material not part of State and agreements Agreement State programs States

• License and oversight of material within their State

• Assist in evaluating other State and national program for consistency 13

Safety cases for near-surface have same range of considerations as high-level waste

• Inventory

• Site Conditions

• Engineering

• Need for Community Outreach Conclusions Differences include

• Additional Focus on Inadvertent Intrusion

• Lessons Learned from Previous Sites Operations 14

Contacts Chris McKenney, US NRC Christepher.McKenney@nrc.gov

+1-301-415-6663 Tim McCartin, US NRC Timothy.McCartin@nrc.gov

+1-301-415-7099 15