PNNL

Featured Event Activities

Vertical Delineation of Groundwater Contamination and Aquifer Properties at DOE Sites

Panel Discussion Featuring: Rob Mackley

MONDAY, MARCH 10

This session focuses on the cost and benefits of vertical delineation of groundwater contamination and aquifer properties for supporting remedial actions such as monitoring, groundwater extraction, and in-situ treatment.  Discussion will focus on DOE sites and issues such as technologies available for vertical characterization, regulatory requirements and policy, vertical data usage, technical and non-technical constraints and barriers, and cost. 

DOE EM Testbeds: A Path to Deployment for Safe and Effective Cleanup

Panel Discussion Featuring: Tom Brouns

TUESDAY, MARCH 11

This session focuses on the DOE EM Test Bed Program. The DOE-EM Technology Development Office (EM-TDO) is advocating the EM site Testbed Program (TBP) to facilitate the use of EM’s unique environments, constructed facilities, and virtual platforms to evaluate innovative research and development and deployment, advance technologies that facilitate, safely accelerate, and cost effectively conduct the EM cleanup work.

The Role of National Laboratories in Delivering Value Through National Missions 

Panel Discussion Featuring: Jud Virden

WEDNESDAY, MARCH 12

This session focuses on the US and Non-US National Laboratories and their role in delivering benefit to the sector and society more broadly. The panel shared their approaches in supporting nationally critical missions ranging from Environmental Restoration to Clean Energy, including how they are building skills and critical nuclear infrastructure for the future.

Transport of MicroReactors

Panel Discussion Featuring: Harold Adkins

WEDNESDAY, MARCH 12

This session focuses on the transport of microreactors, transportable nuclear power plants (TNPPs), and HALEU fuel; package approvals for microreactors; transportation logistics for microreactors and TNPPs; and transportation probabilistic risk assessments for microreactors and TNPPs.

Selected PNNL Waste Processing Presentations at WMS2025

Matt Asmussen

Track 9 - Developing a Hanford Grout Modeling Framework

MONDAY, MARCH 10

Summary: This presentation is an overview of a U.S. Department of Energy Office of Environmental Management project using a multi-organization expert team to produce conceptual models for grout aging at Hanford that can be applied in PAs using a Hanford Grout Modeling Framework.

Reid Peterson

Track 9 - Enabling HLW Sludge Delivery Through In-tank Processing in the Southeast Quadrant of the Hanford Tank Farms

MONDAY, MARCH 10

Summary: Discussion of research aimed at facilitating material transport in the southeast quadrant of the Hanford tank farms. 

Amy Westesen

Track 2 - Disposition of High-level Waste Sludge Retrieval and Leachate Solutions

MONDAY, MARCH 11

Summary: This poster will summarize efforts associated with expediting Hanford High Level Waste treatment. The feasibility of implementing phosphate, fluoride, and aluminum dissolution into sludge pretreatment will be assessed as well as disposition pathways for those leach solutions. 

Track 2 - Technology Development and Characterization for Radionuclide Removal from Hanford Wastes
THURSDAY, MARCH 13

Summary: This presentation will cover efforts to demonstrate the removal of Tc and I from simulated and actual Hanford waste. The influence of speciation on these technologies will also be discussed.

Trenton Graham

Track 7 - Determining Solubility of Aluminum and Phosphate Gels in Hanford Waste

MONDAY, MARCH 10

Summary: The Hanford Site plans to retrieve and immobilize millions of gallons of legacy radioactive waste. Phosphate in the tank waste supernatant creates challenges for waste pumping due to solids precipitating with temperature changes or chemical additions, forming needle-shaped crystals that block pipelines. Knowledge gaps exist regarding phosphate solubility, especially in systems with aluminate and hydroxide. Limited solubility data for multicomponent electrolytes complicate waste management. This work builds on previous studies showing that nitrate and nitrite increase gibbsite solubility. Solubility tests on sodium phosphate and ternary systems identified limiting phases through X-ray diffraction, helping to refine waste management strategies.

Track 2 - Implications of Natrophosphate Solubility for Tank Waste Retrieval from the Southeast Quadrant at the Hanford Site
THURSDAY, MARCH 13

Summary: The presentation aims to enable Direct Feed High-Level Waste to the Waste Treatment and Immobilization Plant at Hanford Site by tackling slurry mixing and transport issues, particularly with high natrophosphate and gibbsite wastes. It addresses the impact on slurry re-suspension, pipeline plugging, and handling high fluoride and phosphate wastes. The work highlights gaps in solubility data for electrolytes in tank waste, especially phosphate, which complicates waste transfer due to risks like filtration issues and pipeline blockages. By investigating natrophosphate and gibbsite solubility in different systems and conditions, the presentation aims to improve waste management strategies.

Selected PNNL Environmental Remediation Presentations at WMS2025

Hilary Emerson

Track 7 - Testing Spectral Induced Polarization for Monitoring In Situ Remediation Technology Delivery and Reactivity

WEDNESDAY, MARCH 12

Summary: Noninvasive geophysical tools can monitor large volumes of the subsurface with relatively high spatial resolution using indirect measures of solution and surface phase biogeochemical processes. Spectral induced polarization is a developing geophysical technique which may be able to indirectly measure changes induced from amendment delivery and reactivity when they induce reactions that impact mineral surface chemistry and polarization (e.g., precipitation or oxidation-reduction reactions). This work demonstrates the ability to non-intrusively evaluate amendment injection delivery and subsequent reactivity at the laboratory scale for a range of materials under consideration for the U.S. Department of Energy’s Hanford Site.

Inci Demirkanli

Track 7 - End-State Driven Performance-Based Optimization Tool for Large-Scale Groundwater Remedies

THURSDAY, MARCH 13

Summary: Performance-based optimization and/or management of P&T remedies is a critical strategy for maintaining contaminant removal effectiveness throughout the remedy’s lifetime and managing systems toward a specific end-state for site completion or remedy transition. In this study, we developed a systematic/computational tool that couples a reduced complexity flow and transport model with formal optimization algorithms to assess the impacts of different P&T management strategies (e.g., decisions on well network adjustments) and site-specific features on multiple remedy objectives, or end-state criteria (e.g., mass removal, or concentration-based end state, etc.). 

Xuehang Song

Track 7 - Enhancing Pump-and-Treat Optimization with a Deep Learning Surrogate Model

THURSDAY, MARCH 13

Summary: This presentation introduces a novel deep learning surrogate model designed to optimize pump-and-treat (P&T) systems for groundwater remediation. By leveraging a U-Net architecture and the Thiem equation, the model accurately predicts contaminant plume distributions while significantly reducing computational time. Validated with complex models from the Hanford Site, this approach offers a more efficient and scalable solution for evaluating P&T well network design. The ability to quickly simulate a range of scenarios supports iterative optimization and enhances decision-making, making this approach potentially applicable to a wide range of remediation sites.

Judy Robinson

Track 7 - Reducing Seismic Imaging Uncertainty to Provide Improved Subsurface Characterization

WEDNESDAY, MARCH 12

Summary: Planning for and monitoring remediation efforts at contaminated sites requires detailed subsurface knowledge. Geophysical approaches are non-intrusive but may yield ambiguous results. Here we combine two seismic approaches to produce independent, but complementary images of the subsurface. We use refracted arrivals to image seismic velocities and reflections to map seismic boundaries. Combining these two images reduces interpretation uncertainties.

Track 7 - Vadose Zone Model Calibration Using Machine Learning with Geophysical Monitoring Data

THURSDAY, MARCH 13

Summary: We present a method of using recent advancements in machine learning to produce subsurface numerical models that honor geophysical monitoring data. Be so doing, the uncertainty in subsurface behavior predictions is approved. We demonstrate the approach using a field application of in-situ vadose zone soil flushing to remediate hexavalent chromium contamination at the Hanford 100 - K East Area.    

Selected PNNL Nuclear Energy Presentations at WMS2025

Laurie Hay

Track 5 - Process for Developing Package Performance Project Protocols

WEDNESDAY, MARCH 12

Summary: The DOE, Office of Nuclear Energy (DOE-NE) is releasing a Request for Information/Sources Sought Notice (RFI/SSN) to consider options for conducting a Package Performance Demonstration (PPD). DOE-NE is considering conducting full-scale demonstrations of a SNF rail-sized transportation cask to help build public trust and confidence in the safety of SNF transportation casks and SNF transportation by rail, heavy‑haul truck, and barge. This paper will discuss the supporting National Laboratory team’s technical approach to providing options and recommendations to DOE-NE based on information including the responses to the RFI/SSN and a PPD Functions and Requirements Document. 

Nicholas Kucinski

Track 4 - Dose Considerations for Determining Land Area for a Large CISF

WEDNESDAY, MARCH 12

Summary: This work focuses on considerations needed to calculate dose beyond the controlled area of a consolidated interim storage facility (CISF) from direct radiation and effluent dose from CISF operations. Factors such as the number of storage casks, cask design, source term, aspect ratio of the CISF storage pad, and occupancy time are discussed in this work. Sensitivity studies are performed showing the impact that these factors have on the dose and the consequent land area of the CISF.

Steve Maheras

Track 5 - Site Infrastructure Evaluation for the North Anna Nuclear Power Station

WEDNESDAY, MARCH 12

Summary: The U.S. Department of Energy Office of Storage and Transportation continues to conduct evaluations of removing spent nuclear fuel (SNF) from nuclear power plant sites and away-from-reactor sites that store commercial SNF. The North Anna site evaluation was performed in May 2024 to support the removal the TN-32B high burnup demonstration cask from the North.

PNNL Speaker Schedule

See the full list of PNNL panelists, presentations, and posters, arranged by track:

Overview of PNNL Support to Hanford Site

PNNL Lab Director Steve Ashby describes PNNL’s science and technology support to Hanford Site cleanup. Read his column here.

Careers at PNNL

If you’re looking for a career at nuclear sciences at PNNL, check out our current openings:

CAREERS IN NUCLEAR SCIENCES