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Harnessing Clean Energy with Stella Architect

The Connector - Fall 2016 Issue

A Big Model for Big Systems

Luc Van Den Durpel Luc Van Den Durpel

Offering real benefits in clean energy, nuclear energy systems also present real challenges. The hard job of understanding and mitigating costs and benefits, projecting short- to long-term consequences, supporting decision-makers, and informing stakeholders is being done by the Dynamic Analysis of Nuclear Energy System Strategies (DANESS) model. Developed and employed by Nuclear-21.Net, DANESS is helping governments, utilities, investors, waste management, and research and development organizations around the world plan, assess, and analyze nuclear energy systems while investigating their sustainability and performance.

Simulations that facilitated decision-making by providing clear projections weren’t available. And the models were certainly not easy to understand

“I started developing DANESS in 1989 when I was working at the OECD Nuclear Energy Agency in Paris,” says Luc Van Den Durpel, Managing Director of Nuclear-21.Net. “There were very technical nuclear energy systems models developed in the 1970s and later, but simulations that facilitated decision-making by providing clear projections weren’t available. And the models were certainly not easy to understand.”

Initially performing cost analysis for nuclear systems, Van Den Durpel gradually expanded the model to DANESS’ wider perspective. “In 2002, I became a consulting engineer at ANL,” says Van Den Durpel. “I saw a growing need in the U.S. for nuclear systems analyses that looked to the future of nuclear energy on a national and global basis, and considered intra-nuclear options.”

I had a constant drive to develop a simulation code that fulfilled my own need to understand the main issues in the deployment of sustainable energy

He continued to develop DANESS to accommodate changing technology and requirements. “To be honest, I had a constant drive to develop a simulation code that fulfilled my own need to understand the main issues in the deployment of sustainable energy.”

Today, DANESS models one reactor, an entire facility, or a worldwide, multi-reactor system and its associated fuel cycles in detail. Material flows and isotopic composition are simulated from mining through final waste disposal. Per component economics including waste impact on disposal sites are analyzed and risks are assessed.

Nuclear-21.Net is both the model’s developer and most advanced user. “DANESS is one of the building blocks of our consultancy assignments,” says Van Den Durpel. “Our clients hire us in support of their decision-making processes. They don’t need to use DANESS on their own but do need it to serve as a valid assessment environment.”

Our clients hire us in support of their decision-making processes

DANESS continues to serve in this capacity for nuclear energy planners and policy makers who assess the impacts of very complex systems. “Such impacts relate to the competitiveness of nuclear energy, the amount and kinds of radioactive waste to be produced and managed, and the amount of natural uranium or fuel cycle services required during the next years and decades,” says Van Den Durpel.

For example, DANESS has allowed Nuclear-21.Net clients to:

  • Consider nuclear fuel cycle options and establish the technical-economic criteria analysis that should be applied when new options hit the market
  • Compare intra-nuclear system options to, for example, identify the best fuel cycle options, optimize fuel cycles, or analyze cash flow and investment prospects
  • Quantify the amount and kind of radioactive waste to be managed in a country, allowing its government waste agency to time and design the required waste management facilities
  • Conduct a full, in-depth, reactor-per-reactor analysis of a country’s nuclear reactor park along with nuclear materials inventories and flows to assess the need and market availability of specific storage solutions

As in any Systems Thinking effort, Van Den Durpel and his team hope to understand and avoid unintended consequences of decisions and actions. DANESS has proven an able technology in that effort. “Recently, we used DANESS to detail the market prospect for a nuclear technology park,” he says. “Our analysis showed unprecedented market uncertainties that would have a major impact on the technical and economic performance of the park. That helped us determine the optimal timeframe for introducing specific technologies and economic conditions into the market.”

The heavy lifting on the modeling and simulation needed to conduct those analyses is accomplished through Nuclear-21.Net development, relevant databases, and iThink from isee systems. “In the early 2000s, iThink was the true reference system in system dynamics,” says Van Den Durpel. “It allowed us to progress very quickly and reliably in developing the predecessors of DANESS. Continuous development by isee systems provided confidence in the alignment of our needs with their product roadmap.”

Customer Value Perception across regions

DANESS is a demanding model and it did eventually bump into iThink memory limits. Those limitations have been erased with iThink 10 and Stella Professional. “We don’t see anything standing in the way of pursuing development of DANESS and other associated models using isee systems applications,” says Van Den Durpel. “isee systems always shows the openness and willingness to further their and our development. We share a passion for system dynamics and iThink’s and Stella’s ability to run these huge models that simulate nuclear energy systems worldwide.”

Impact on service interruptions over time

Nuclear-21.Net’s relationship with isee systems is central to plans for DANESS and continued work in energy system analysis. “We’ve had increasing requests to apply our modeling to energy systems as a whole and conduct technical-economic assessments over time,” says Van Den Durpel. “We’ve developed Dynamic Energy Market Assessment (DEMA) with Stella and, in parallel, developed associated databases of worldwide energy technology and market information. Those developments are being regrouped in a new toolbox.”

We don’t see anything standing in the way of pursuing development of DANESS and other associated models using isee systems applications

Most of Nuclear-21.Net’s models are used in business and government settings but an increasing need for energy system analysis in educational setting is leading to other product extensions. “We anticipate releasing a web-based version for educational use in 2017,” says Van Den Durpel. “There have been too many energy policies that didn’t take a systems view and led to underperformance. We hope we can provide the next generation of energy experts with tools to help them decide what the sustainable energy system of the future will look like.”

The Economics and Environmental Impact of Thneed Production: Teaching Systems Thinking with The Lorax

Sarah Marcus Sarah Marcus

Dr. Seuss books have taught young readers many things: how to run a zoo, the fun of hopping on Pop, or what happens when you wish you had duck feet. Theodore Geisel probably never imagined that one of his last books, The Lorax, would be used to teach high school students about Systems Thinking.

We were really impressed by the work Middle School science students were doing using Systems Thinking and Stella

Published in 2012 by The Creative Learning Exchange, a non-profit dedicated to the development of Systems Citizens in K-12 education, The Lorax lesson has become an important part of Sarah Marcus’ high school science lesson plans. Marcus, who now teaches earth and physical science, biology, AP environmental science, anatomy and physiology, and forensic science at Proctor Junior/Senior High School in Rutland, Vermont, discovered Systems Thinking, Stella, and The Lorax lesson when she was in graduate school at the University of Vermont.

“When I was student teaching at Montpelier High School, I visited Vermont Commons School with my mentor teachers, Sam Bromley and Katy Chabot,” says Marcus. “We were really impressed by the work Middle School science students were doing using Systems Thinking and Stella. I decided that I wanted to use Stella during my solo teaching experience and stumbled upon The Lorax exercise on the Creative Learning Exchange website when I was looking for ideas.”

Systems Thinking forces kids to really spend time and analyze an issue or concept... They find connections and see relationships which is an important skill for everything in their life

Marcus wasn’t just looking for something new to do. She immediately saw the important role Systems Thinking plays in education. “Systems Thinking forces kids to really spend time and analyze an issue or concept,” she says. “They find connections and see relationships which is an important skill for everything in their life.”

She also realized that learning to think systemically and use Systems Thinking concepts and vocabulary would be a challenge to students who were used to being told information and what to do. That’s where The Lorax exercise comes in.

Most students are familiar with The Lorax either through the book or the movie... It’s comfortable and we’re able to review something familiar and start simple

“Most students are familiar with The Lorax either through the book or the movie,” says Marcus. “They really enjoy going back to things they know from childhood. It’s comfortable and we’re able to review something familiar and start simple.”

For those who don’t remember the story of The Lorax, it’s a simple, compelling look at the relationship between entrepreneurship (the Onceler’s invention of thneeds), natural resource utilization (thneeds are made out of truffula trees), profitable manufacturing, greed, and environmental impact. “Students look for elements in the story that change, what causes the change, and how those changes impact other elements,” says Marcus. For example, cutting down truffula trees enables the Onceler to make more thneeds which eventually decimates the truffula tree and impacts the environment.

“The kids work in groups to break the entire system down into subsystems,” says Marcus. “They identify links between story elements and use those links to create feedback loops.” Students note that some loops are reinforcing – making more thneeds increases profits – and others are balancing – cutting down more truffula trees decreases the stock of available trees.

Students look for elements in the story that change, what causes the change, and how those changes impact other elements

Marcus has tweaked the Creative Learning Exchange exercise to include Stella. She uses pre-built maps to help students understand stocks, flows, and converters. “It takes time for students to learn how to build maps,” says Marcus. “They often struggle with naming flows and understanding the difference between stocks and converters but once they get the hang of it, they really enjoy the exercise.”

Systems Thinking and Stella also force students out of their educational comfort zone, which inspires deeper learning. “Kids are so used to being told what to do all the time,” says Marcus. “They’re great at following directions but that’s not the point of Systems Thinking. When they get stuck, I don’t give them an answer. I prod them with questions or give them a few hints.”

Thneed Production Causal Loop Diagram of Thneed Production

While Marcus introduces her students to Systems Thinking and Stella with The Lorax, their modeling experience doesn’t end there. “Many students have ah-ha moments when we move on to connect maps of the water and carbon cycle,” she says. “We look for connections and overlaps between the two and I challenge students to add human impact. They quickly realize the many, many ways humans impact those cycles and see how related the systems are.”

Systems Thinking and Stella also tie in with the Next Generation Science Standards (NGSS) that have been developed by the National Research Council and adopted by 26 states including Vermont. Included in NGSS Framework are scientific and engineering practices – students are required to learn how to ask questions and define problems, plan and carry out investigations, present findings and evidence, and be able to identify causes, effects, and patterns. “Stella helps students learn and demonstrate proficiency with many parts of the framework,” says Marcus.

We look for connections and overlaps... They quickly realize the many, many ways humans impact those cycles and see how related the systems are

Working at a small school and teaching so many classes allows Marcus and her students to apply Systems Thinking to a wide range of systems and scientific concepts. “I’m looking forward to learning more about Stella and getting my advanced students to build more complex models that include math and data,” says Marcus. “Once kids learn how to think in a systems way, they can really take off.”

To learn more about The Lorax exercise, visit

Systems in Focus

Systems are all around us. Using Systems Thinking, we can better understand them by building models that can be simulated. These videos show common systems overlaid with the underlying dynamics that make them behave as they do. By looking beneath the surface, we are better able to bring these systems into focus. An example of a simple bottle manufacturing process is our most recent System in Focus.

One of the greatest environmental challenges we face is how to do more with less: Less raw materials, less pollution, less damage to the environment. This model shows the life-cycle assessment for the aggregate products manufactured and consumed in a firm, an industry, a region, a nation, or the world. It focuses on solid waste, though it would be easy to add air or water pollution generated and energy consumed at each stage.

Looking for more Systems in Focus?

Story of the Month: Reissue

The Story of the Month series was originally issued starting in May of 2001. While many things have changed since then, many of the issues remain relevant. From corporate corruption, to terrorism, to greenhouse gasses, each story analyzed a past headline news topic from a systems thinking perspective. These topics were modeled using STELLA or iThink with the hopes to gain perspective on the system, stimulate discussion and perhaps adjust our assumptions. isee systems has been re-releasing each Story of the Month from our archives, as originally developed, with an easy-to-access isee Sim Exchange.

This Story of the Month reissue examines the complexities of school reform. Inspired by a major school reform effort in Philadelphia, this story explores some of the potential unintended consequences. What happens when the focus of "fixing schools" becomes increasing scores on standardized tests?

On the Road

As Autumn sets in for isee systems in New Hampshire, Co-President Karim Chichakly will be headed south to warmer weather! This year Karim will be attending as program chair of the 14th Annual Latin American Conference on System Dynamics (CLADS) from October 19 -21st in São Paulo, Brazil! Karim will also be conducting a workshop and presenting a plenary talk. This will be our third year in attendance at CLADS. We are very excited to showcase our new software Stella Architect and hear about the work being done by practitioners in the southern hemisphere. Kim Warren, Etiënne Rouwette, and Hazhir Rahmandad will also be presenting plenaries and giving workshops in what promises to be a great conference for networking and learning!

At the end of October, Software Developer Billy Schoenberg will be headed to the University of Bergen in Norway to instruct the two-week course System Dynamics Learning Environment Design and Development. The course will teach students the fundamentals of learning environment design and development, as well as to expose students to multiple types of learning environments (flight simulators, war games, scenario analysis tools, etc).

Stella Architect

If you have not checked out our new software Stella Architect yet, now is a great time!

Stella Architect offers all of the amazing modeling functionality developed by isee systems, as well as our new model interface design and publishing tool! Stella Architect enables you to create interactive dynamic models with a professional finish. As with Stella Professional, we have completely rebuilt the interface design tool and included the functionality of isee NetSim. Models can now easily be published to the web using HTML5, allowing the published simulations to be run on any device that has access to a web browser. Models will be published on our new isee Exchange for free under the Creative Commons license. We also offer private publishing options.

The Stella Architect crossgrade sale from September was so popular we decided to extend it until October 31st! Crossgrades start at $299 for Non-educator and $149 for University Faculty members. Contact us today to inquire about moving up to Stella Architect!

Looking for more Products?

New Website

Sarah Marcus

A year ago, we took a look at our website and determined that it was no longer serving our customer's needs to the best of its ability. So we took a close look at user behavior to get a better understanding of what is important to our customers in 2016. Using that information, we stripped everything down to the core and crafted a new, consistent, and engaging experience.

From the Home page, to the Checkout process, the entire experience has been redesigned and streamlined to get you where you are going with the information you need. We have all new Product pages that quickly and simply highlight features and common uses. If you are new to our software, the new Solutions section shows examples of how our software can specifically be used across a number of core disciplines. If you have questions, a new Resources section contains FAQs and Help documentation, so you can quickly find the answers you are looking for. Best of all, with a fully responsive design and an all new mobile experience, you can now enjoy our website and services like Online Training on the go.

A website is a constant work in progress and we are always looking for ways to improve your experience. If there's anything you think is missing or would like to see added, please let us know!

isee Exchange

We are excited to introduce the isee Exchange, our free online web hosting service for models published with Stella Architect. The isee Exchange allows you to publish your models under your account with a title, description, and keywords that help other users find your models. In publishing your models on the isee Exchange you receive a link directly to the model allowing you to share a specific model with customers, partners, or classes. Models published to the isee Exchange can also be embedded into your own website so customers or students do not have to leave your website. Our hope is that the isee Exchange becomes a community of practitioners sharing their models for everyone to view and to learn. Visit the isee Exchange to see all the currently published models!

Private Publishing

If you are interested in publishing models privately to the isee Exchange, isee systems offers several options. One option is to restrict access to your model using user and password authentication. Another option is to publish the model to your own (or client's own) server with custom branding.

Both of these options are charged for on a per model per month basis. Volume discounts are available when publishing 5 or more models and/or time commitments of one year or longer. Additional options are also available, including unlimited publishing on your own server(s). Please inquire for more information.

Recent Posts

Fall 2018 Issue

Public health organizations combat alcoholism with Stella, the Social System Design Lab applies system dynamics to community projects, the Cohort simulation helps managers and leaders learn to facilitate change, the 2018 Barry Richmond Scholarship Award winner is announced, new software and licensing features, the 38th annual Prouty, and isee systems heads to Iceland and Mexico…

Fall 2017 Issue

The Ulupono initiative investigates Hawaii food production with systems thinking, African leaders embrace a systems thinking approach to problem solving, a new online training course in creating learning environments, Stella Online has been added to the isee Exchange and exciting updates to Stella Architect...

Fall 2016 Issue

Stella Architect is used to better understand nuclear and other clean energies, high school students learn systems thinking from The Lorax, Systems in Focus looks at waste manangement, Story of the Month: Reissue examines school reform, isee systems heads to Brazil, Stella Architect is released, the company website gets an overdue update...

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