# Presentation: 513566

## Role of ITER in Fusion Development

**	**
**	****Farrokh  Najmabadi**
**	****University of California, San Diego, **
**	****La Jolla, CA**** **
- FPA Annual Meeting
- September 27-28, 2006
- Washington, DC
- 	Electronic copy: http://aries.uscd/edu/najmabadi/
- 	**ARIES Web Site: http://aries.ucsd.edu/ARIES/**

## A 35,000 ft viewof fusion development landscape

## ITER

***ITER***

***Integration of fusion plasma with fusion technologies***

***A  1******st****** of the kind Power Plant! ***

- “Fusion Power: Research and Development Requirements.”
- Division of Controlled Thermonuclear Research (AEC).

## World-wide Development Scenarios use similar names for devices with different missions!

**World-wide Development Scenarios use similar names for devices with different missions!**

- Commercial

- ITER + IFMIF + Base

***An R&D Device***

***A Power Plant***

## What do we need to bridge the gap between ITER  and attractive power plants?

**What do we need to bridge the gap ****between ITER  and attractive power plants?**

- With ITER construction going forward with US as a partner and increased world-wide interest and effort in developing fusion energy, it will become increasingly important that new _major_ facilities and program in US demonstrate their contributions to developing fusion energy as a key part of their mission.
- Do we have a _detailed map_ for fusion power development?
- How do we optimize such a development path?
- What can we do in simulation facilities and what requires new fusion devices?
- How can we utilize existing devices to resolve some of these issues?
- Preparation for lunching new facilities.
- Resolving issues that can make a difference in any new facilities.

## We need to develop a 5,000 ft view

## Various devices are proposed in US to fill in the data needed to proceed with a power plant

**Various devices are proposed in US to fill in the data needed to proceed with a power plant**

- Many devices are proposed:
- A device that can explore AT _burning_ plasma with high power density and high bootstrap fraction (with performance goals similar to ARIES-RS/AT).
- A device with steady-state operation at moderate Q (even D plasma) to develop operational scenarios (i.e., plasma control), disruption avoidance, divertor physics (and developing fielding divertor hardware), etc.
- Volume Neutron Source for blanket testing.

- Most these devices provide only some of the data needed to move to fusion power.  They really geared towards one part of the problem.
- Can we do all these in one device or one facility with minor changes/upgrades and a reasonable cost?
- How can we utilize existing devices to resolve some of these issues?
- _What is the most cost-effective way to do this?_

## A holistic optimization approachshould drive the development path.

- Traditional Approach:  Ask each scientific area (i.e., plasma, blanket, ...)
- What are the remaining major R&D areas?
- Which of the remaining major R&D areas can be explored in existing devices or simulation facilities (e.g., fission reactors)? What other major facilities are needed?

- Holistic Approach:  _Fusion energy development should be guided  by the_
- _requirements for an attractive fusion energy source_
- What are the remaining major R&D areas?
- What it the impact of this R&D on the attractiveness of the final product.
- Which of the remaining major R&D areas can be explored in existing devices or simulation facilities (i.e., fission reactors)?  What other major facilities are needed?
- Should we attempt to replicate power plant conditions in a scaled device or Optimize facility performance relative to scaled objectives

## Fusion energy development should be guided  by the requirements for a fusion energy source

- No public evacuation plan is required
- Generated waste can be returned to environment or recycled in less than a few hundred years (*i.e.,* not geological time-scales)
- No disturbance of public’s day-to-day activities
- No exposure of workers to a higher risk than other power plants
- Closed tritium fuel cycle on site
- Ability to operate at partial load conditions (50% of full power)
- Ability to efficiently maintain power core for acceptable plant availability
- Ability to operate reliably with less than 0.1 major 		unscheduled shut-down per year

**Above requirements must be achieved consistent with a competitive life-cycle cost-of-electricity goal.**

## Existing facilities fail to address essential features of a fusion energy source

## ITER is a major step forward but there is a long road ahead.

## Power plant features and not individual parameters should drive the development path 

- Absolute parameters

- Dimensionless  parameters

## A holistic optimization approachshould drive the development path.

- Traditional Approach:  Ask each scientific area (i.e., plasma, blanket, ...)
- What are the remaining major R&D areas?
- Which of the remaining major R&D areas can be explored in existing devices or simulation facilities (e.g., fission reactors)? What other major facilities are needed?

- Holistic Approach:  _Fusion energy development should be guided  by the_
- _requirements for an attractive fusion energy source_
- What are the remaining major R&D areas?
- What it the impact of this R&D on the attractiveness of the final product.
- Which of the remaining major R&D areas can be explored in existing devices or simulation facilities (i.e., fission reactors)?  What other major facilities are needed?
- Should we attempt to replicate power plant conditions in a scaled device or Optimize facility performance relative to scaled objectives

## ARIES studies emphasize holistic R&D needs and their design implications 

- Plasma
- Blankets
- Divertors
- Magnets
- Vacuum vessel

**Traditional approach**

- This approach has many benefits (see below)

## Examples of holistic issues for Fusion Power  

- _Power & Particle management_:  Demonstrate extraction of power core high-grade heat, divertor power and particle handling, nuclear performance of ancillary equipment.
- _Fuel management_:  Demonstrate “birth to death” tritium management in a closed loop with self-sufficient breeding and full accountability of tritium inventory.
- _Safety_:  Demonstrate public and worker safety of the integral facility, capturing system to system interactions.
- _Plant operations_:  Establish the operability of a fusion energy facility, including plasma control, reliability of components, inspectability and maintainability of a power plant relevant tokamak.

## Power & particle management:  Demonstrate extraction of power core high-grade heat, divertor power and particle handling, nuclear performance of ancillary equipment.

**Divertor**

**First wall**

**P****rad**

**P****cond**

**In-vessel**

**PFC’s**

**P******

**P****injected**

**P****fusion**

**core**
**power**

***rf antennas, magnets, diagnostics, etc.***

**edge**
**power**

**P****rad**

**P****cond**

**Fusion****:**

**P****neutron**

**Blanket**

## A holistic approach to Power and Particle Management

- Does not allow problem cannot be solved by transferring to another system:
- A 100% radiating plasma transfers the problem from divertor to the first wall.
- Allows Prioritization of R&D:
- Systems code can be used to find power plant cost (or any other metric) as a function of divertor power handling.  This leads to a “benefit” metric that can be compared to other R&D areas, for example increasing plasma .  We can then answer: should we focus on power flow or improving plasma .
- Solution may come from other areas:
- Low recirculating power
- A higher blanket thermal efficiency reducing input fusion power
- This area may have a profound impact on next-step facilities.

## Fuel management:  Demonstrate “birth to death” tritium management in a closed loop with self-sufficient breeding and full accountability of tritium inventory.

## Fuel Management divides naturally along physical boundaries

- Can & should be done in a fission facility.
- Demonstrate in-situ control of breeding rate (too much breeding is bad).
- Demonstrate T can be extracted from breeder in a timely manner (minimum inventory).

## There is a need to examine fusion development scenarios in detail

- Any next-step device should advance power plant features on the path to a commercial end product.
- 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
- An integrated, “holistic” approach provides a path to an optimized development scenario and R&D prioritization.
- We should consider the needs of next-step facilities in the R&D in current facilities as well as initiating R&D needed to ensure maximum utilization of those facilities.