ARIES Program
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ARIES-"TNS" Project Planning Meeting Minutes

3-4 April 200

University of California, San Diego

Documented by L. Waganer

Organization ARIES Compact Stellarator
Boeing Waganer
General Atomics Luce, Schultz, Taylor, Turnbull
Georgia Tech Abdel-Khalik, Yoda
INL Longhurst, Sharp
PPPL Gates, Kessel, Menard, Zarnstorff (phone)
UCSD Dragojlovic, Malang, Mau, Najmabadi, Raffray, Sze, Tillack, Wang
UW-Mad El-Guebaly

Ref: Agenda and Presentation Links: Project and Review Meeting Agenda


Welcome – Les Waganer welcomed the ARIES team to UCSD and thanked the UCSD team for providing refreshments and the meeting room. Les reviewed the agenda covering the preparation of the papers for the ARIES-CS study final report and the planning discussions for the new ARIES project.

Compact Stellarator Final Report Papers

Discussion about ARIES-CS Paper Status and Action Items - Rene Raffray told the group that 11 of the ARIES-CS papers had been reviewed by the team, revised, and are ready to be submitted. The final paper is the overview document that Farrokh Najmabadi is writing. Early in April, the papers will be submitted to the ANS Fusion Science and Technology for publication. Rene will send out a note later with more details.

ARIES "Pathways" or "The Next Step" Program

General Scope of and Schedule for the Next Study – Farrokh Najmabadi discussed the mission of the ARIES “Pathways” program, which is to investigate the needs to transform the present state of fusion technology to that required for commercial application, define the end state of a DEMO plant, and to define the steps between ITER and DEMO. The current development vision is very similar to that described in 1973, Wash-1267, except for the timeframe. The world-wide fusion communities generally envision the same development steps, with somewhat different names and maybe combined differently.

This next ARIES study is directed to identify the specific issues remaining and provide a detailed map of fusion power development to minimize the risks to proceed to commercial fusion electric power. The new approach is to assess those global plant parameters that power providers consider necessary for endorsing and sponsoring a new power technology. Some tentative parameters would include cost, waste, reliability, maintainability, fuel, safety, partial power, thermal efficiency and power density. The specific schedule of activities is not important at this time.

The first year of the study would focus on defining R&D issues identified by an advisory committee and developing the ARIES Systems Code to perform tradeoff studies and identify the high leverage areas for power plants. The second and third years would develop the embodiment of the next-step device and ancillary machines.

Determining the Needs of the Fusion Pilot Plant– Ken Schultz recommended an advisory committee to help establish the goals, objectives, and specific metrics of the pilot plant, similar to the one convened for the ARIES DEMO study in 1994. He identified a few candidate advisory committee members and solicited the team to nominate other members. He identified the fundamental requirements for acceptance of a publicly owned fusion power plant. Identification of the Demo or pilot plant will help formulate the needs for the intermediate development and validation facilities necessary to lower the developmental risk for the Demo plant.

Approach for Analysis of R&D Needs and Facilities for Fusion Energy – Mark Tillack showed how the customer needs could be derived from the requirements of the power plant, such as Starlite. The focus will be on integrated issues rather than on specific component or system issues, with some examples provided for discussion. He emphasized that the experimental reactor will require more emphasis on operational concerns and demonstration of intermediate global plant goals.

Towards an Integrated View of Post ITER Tritium Requirements– Phil Sharp summarized the quantities and through-put of tritium in ITER. He showed the fuel handling systems with the ITER party participation. The predicted tritium availability was shown with the assumption of present CANDU production and different ITER use scenarios. The end result shows a very significant reduction of worldwide tritium available with most ITER use scenarios. ITER demonstrates most tritium fuel management goals except generation and extraction of tritium and full accountability in an operating blanket system. Important questions are a) where TNS will get its tritium (may need to generate its own tritium) and b) will the blankets be sufficiently developed with acceptable risk for the TNS.

Overview of Steady State Scenario Development Activities – Tim Luce explained how the DIII-D experimental program is aligned with the major fusion program goals to provide steady state model integration, demonstrate ITER physics, advance fundamental fusion plasma science, validate integrated modeling, and develop state-of-the-art plasma control systems. Tim then explained how DIII-D is approaching and validating each of these goals. They have a 5-year program to advance the ITER and FDF operation and the DEMO-Advanced Tokamak beta-N = 5 regimes. Heat flux management is also a challenging goal. Controllability of advanced tokamak systems may be as important as determining the real cost. Tim identified the criteria that need to be satisfied in the next five years to be ready to proceed toward commercial fusion power plants: a validated plasma scenario, substantial physics basis, independent verification of ITER and FDF scenarios, and determination of heating and current drive system control demands. Also a reasonable expectation of achieving a beta-N of 5 or greater is a reasonable expectation to move forward.

Development and Scope of Systems Code – Zoran Dragojlovic explained the purpose of the new ARIES system code is to establish a high fidelity database of performance and cost to assess the impact of different plant parameters and options. The program is being constructed completely from scratch but will capture the essence of the prior code and experience from prior ARIES studies. Rather than using point solutions, the code is designed to expose parametric trends with faster execution times. There will be predefined options for the various plant configurations to be used in the different trade studies. Zoran showed the current capability to define and display the power configuration and significant geometric parameters. He illustrated the results from a trial run with initial data. It was mentioned that although these results were listed as “optimal”, the cost algorithms were not loaded; hence it was not really representative of an optimal solution.

Systems Analysis Development for ARIES Next Step – Chuck Kessel said the current ARIES Systems Code is very cumbersome and has lost its technical maintenance. Most codes search for an optimum operating point. It might be better to have a code to generate a general operating space that can be used in conjunction with the engineering and cost algorithms to explore a more global optimal solution space. Chuck has generated a set of physics solutions that map out a large operating space that can be used in the systems code as basic solutions. He initially generates a large number of physics solutions and filters out the non-viable engineering solutions that do not satisfy engineering constraints. In the near term, he envisions a higher fidelity code that yields improved solution sets.

Systems Cost Code Development and Usage – Les Waganer presented the status of the Systems Code costing algorithms. Laila El-Guebaly will assist Les in developing and refining these algorithms and provide engineering support data and constraints. Les outlined the criteria, impediments, and approach to generating reasonable fidelity cost estimates. Les illustrated the plant factors that influenced the cost of electricity to gain an appreciation of impact of the influencing factors. Les pointed out that some of the ARIES indirect cost factors did not correspond with the published summary table of cost factors. Les defined the proposed costing basis and the approach to be followed in the study.

Engineering Input to Systems Code and Tradeoff Studies to Assess Sensitivities of Major Function to Engineering Parameters – Rene Raffray schematically illustrated the forthcoming ARIES Study in Phase I and II. He summarized the engineering inputs to the systems code with the major options identified. The Blanket and Divertor systems are key factors with heat flux being a major parameter and differentiator between design approaches. Different design approaches determine the heat transfer media temperature limits and, hence, different power conversion techniques and efficiency regimes. The neutron wall load parameter significantly influences the design approach on the blanket system, affects the component lifetime, determines the cooling requirements, and specifies the shielding requirements. Waste treatment is also a significant factor along with the magnetic field.

Groundrules, Bases, and Definitions to Scope “The Next Step” – Les Waganer explored the possible timing of the results from ITER, when the TNS might be designed, constructed, and operated, and the same for the Demo given different scenario assumptions. There are a lot of assumptions on what information is needed for each development step, how that information is demonstrated, and how that information is utilized to define the next device. Les discussed the basic assumptions, groundrules, and definitions for the current and future experimental devices. Demo and TNS metrics are different and these metrics will shape the future development devices.

Project Roles, Action Items, and Next Meeting Date/Location – Farrokh Najmabadi thought the team had laid out the right approach to address the future needs for the next step device. We must decide what is needed, how to quantify and rank those needs, and the approach to meet those development needs. Working groups were identified to address each of the key performance areas. Specific action items were identified to be accomplished over the next few months prior to our next project meeting. These action items are listed below.

Les Waganer is to send out a query on possible dates and locations for the next meeting, approximately mid to late June or early July. The next conference call will be in the second week of May.

Action Items:

The Engineering action items below support the development of the Systems Code including parameter inputs and trade-off studies at function level for input into Systems Code:

1. Continue system code development including incorporation of engineering input and cost algorithms (UCSD, PPPL)

2. Provide updated cost algorithms as input to system code (Boeing, UW)

3. Provide blanket definition and parameters (including coupling to power conversion system) as input to system code for DCLL and self-cooled Pb-17Li with SiC/SiC (thermal-hydraulic parameters (UCSD), radial build (UW))

4. Assess impact of heat flux accommodation on choice of materials and grade level of heat extraction for divertor (UCSD, GIT)

5. Provide input on coil material and parameters to system code (MIT)

6. Assess implications of waste treatment on power plant design requirements (UW)

7. Assess impact of power core component design choice on reliability, availability and maintainability (RAM) (Boeing/INL)

8. Evaluate impact of tritium breeding and recovery on fuel management, safety and cost (INL/UW)