GoldSim, developed by GoldSim Technology Group, is a powerful and flexible computer simulation environment, much like an advanced programming language. While it is capable of modeling financial systems and the reliability of complex systems, Neptune’s principal uses of it are oriented towards the assessment of risk from contaminated environments. Since we are an environmental decision support company, we use these models to understand the effects of uncertainty in complex systems, and to help decision makers faced with difficult, uncertain, and often expensive decisions. We are recognized by GoldSim Technology Group for being Certified Solution Providers and Certified Training Providers.

GOLDSIM MODELing

Neptune is a recognized leader in developing models for various applications using the GoldSim simulation software platform. We provide expertise in designing and constructing GoldSim models, or in advising on modeling developed by others. Below are listed several projects that were developed by Neptune, or for which Neptune consulted on their development.

Radiological Performance Assessment Models

Neptune is an internationally recognized leader in the design and construction of radiological probabilistic performance assessment models using GoldSim and other supporting software. These PA models are collected here on the Performance Assessment page.

GoldSim Water Resource Models

HYDROPOWER DAM SAMPLE MODEL

Neptune has built a GoldSim water resources model that illustrates the operation of a collection of real hydropower dams along the Missouri River in Great Falls, Montana. The objective of this particular exercise is to evaluate the effects of different operations scenarios on the water flow through the system, on requirements for minimum flows through the system, on reservoir pool elevations, and on the generation of electrical power, given various constraints and simplifying assumptions. This is a real-world example, using data from an Environmental Impact Statement to evaluate the effects of proposed changes in Great Falls hydropower dam operations under the constraint that minimum flows for fish populations be maintained in the Missouri River below the dams.

GoldSim Decision Models

Neptune is all about environmental decision making, so naturally we have developed decision models. In some cases, we have used the GoldSim modeling platform for this. Additional information on Neptune’s capabilities regarding decision analysis and risk management is here. Below are three examples of decision models in GoldSim authored by Neptunians.

AN EXAMPLE DECISION MODEL

This example decision model was developed as a generic version of an actual decision model, so that the details could be shared.

The model probabilistically evaluates costs, worker doses, doses to the public, and public acceptance as decision metrics. These various factors are not normalized to a single utility metric, since they really cannot be, and decision makers must understand the trade-offs.

LANL RH-TRU DECISION MODEL

The DOE has a difficult decision problem regarding the fate of some specific Remote-Handled Transuranic (RH-TRU) wastes stored at the Area G disposal facility. Neptune was requested by Predicus, who contracted with DOE to work the problem, to produce a GoldSim-based decision model that would help DOE determine a path forward for these wastes, in light of uncertainties in the decision process.

While the details of this model remain proprietary, the model did provide a template for constructing a more generic decision model as an example.

SMOKY SITE OPTIONS ANALYSIS MODEL FOR THE NNSS

At the northern end of Yucca Flat at the Nevada National Security Site (NNSS, formerly the Nevada Test site) is the Smoky Site. This is the site of an aboveground tower test that distributed plutonium, americium, uranium, and other radioactive materials on the ground. This was not a thermonuclear test, but rather a “hydrodynamic” subcritical test that did not cause nuclear reactions.

At some later point in time, an electrical power line was constructed across the debris field. This power line, like all power lines, requires maintenance. DOE-NV had to make a decision about how this maintenance could safely be performed, and requested that Neptune develop a decision model to inform that decision.

This was Neptune’s first decision model built in GoldSim, and includes little in the way of contaminant transport. It resulted in the implementation of a way to maintain the power lines that is safe for the workers.

GoldSim Training

Dr. Katie Catlett and Aaron Bandler, M.S., at Neptune are Certified GoldSim Training Providers and are available for basic or customized training classes or special individualized training. Katie truly enjoys interacting with people and working on GoldSim applications, ranging from simple models for a high school classroom to complex models in a variety of technical areas. Aaron has expertise with the GoldSim Contaminant Transport Module, as well as with linking external hydrological models to GoldSim with the GSPy (Python) library.

GoldSim training classes are offered for beginning to advanced users, for groups or individuals. Please contact Katie Catlett or Aaron Bandler for more information.

Training and Model Construction Assistance for Korea

Neptune was engaged to provide several rounds of GoldSim performance assessment model training to institutions and individuals from South Korea, regarding the radioactive waste disposal sites at Wolseong. We worked with both the regulator, Korea Institute of Nuclear Safety (KINS), and the implementing organization, Korea Radioactive Waste Agency (KORAD).

Transient Unsaturated Flow and Transport using GSPy and HYDRUS-1D

Neptune developed the first GoldSim implementation of a numerical flow model with the GSPy library. In our example model, we use GoldSim’s stochastic framework to generate weather data and soil parameters, and pass them to HYDRUS-1D through a custom Python script. HYDRUS returns flow velocities and soil saturation to GoldSim, and GoldSim handles the contaminant transport calculations. This method could be especially useful for mine water challenges such as heap leaching and tailings management, as well as landfill design and performance. This work was presented to the GoldSim user community and can be found here.