FPN06-72

Najmabadi Urges Holistic Fusion Development Path

October 27, 2006

Fusion Power Associates held its annual meeting and symposium on September 27-28, 2006 in Washington, DC. The theme of the meeting was "Fusion: Pathways to the Future." At the meeting, Farrokh Najmabadi (University of California, San Diego) presented a paper, "ITER on the Path to Fusion Energy."

He began by giving "a 35,000 ft view of the fusion development landscape." He noted that the basic facility steps to fusion had not changed since the 1973 US Atomic Energy Commission plan, but the time scale had. Then, operation of a demonstration power plant was projected for the year 2000. He said that other countries have provided similar strategies but use a variety of names for essentially the same facility missions.

Najmabadi then addressed the question "What do we need to bridge the gap between ITER and attractive power plants?" In other words, he said, "We need to develop a 5000 ft view." He said that various devices have been proposed to fill in the data needed to proceed from ITER to a power plant. For example, he noted, a device that can explore advanced tokamak burning plasma with high power density and high bootstrap fraction, with performance goals similar to the ARIES-RS/AT power plant design; a device with steady-state operation at moderate (even a deuterium plasma) to develop operational scenarios (i.e., plasma control), disruption avoidance, divertor physics (and developing divertor hardware), etc. and a Volume Neutron Source for blanket testing. "Most of these devices provide only some of the data needed to move to fusion power," he said, "They are really geared towards one part of the problem." He asked, "Can we do all these in one device or one facility with minor changes/upgrades and at reasonable cost? How can we utilize existing devices to resolve some of these issues? What is the most cost-effective way to do this?" He said, "A holistic optimization approach should drive the development path, i.e., fusion energy development should be guided by the requirements for an attractive fusion energy source."

Najmabadi listed the "requirements for a fusion energy source" as:
- No public evacuation plan
- Waste that can be recycled in less than a few hundred years
- No disturbance of public's day-to-day activities
- Closed tritium fuel cycle on site
- Ability to operate at partial load conditions (50% of full power)
- Ability to efficiently maintain the power core
- Ability to operate reliably

The above requirements "must be achieved consistent with a competitive life-cycle cost of electricity," he said.

The traditional approach to fusion development focuses on such areas as "plasma, blankets, divertors, magnets and vacuum vessel." The holistic approach would focus on such areas as "power control, power and particle management, fuel management, maintenance, safety, waste, and cost," he said. He said that the traditional approach allows problems to be solved in one area at the expense of making the problem harder in other areas. In the holistic approach, tradeoffs are considered among areas that benefit the system as a whole. This approach "may have a profound impact on next-step facilities," he said.

"We need to start planning for facilities and R&D needed between ITER and a power plant. Metrics will be needed for cost/benefit/risk tradeoffs," he said. He concluded, "An integrated, holistic approach provides a path to an optimized development scenario and R&D prioritization."

Najmabadi's presentation is posted at http://fire.pppl.gov/fpa06_najmabadi.ppt. He can be contacted at: fnajmabadi@ucsd.edu