Plasma Exhaust ProcessingPlasma Exhaust ProcessingClosing the Fuel CycleClosing the Fuel Cycle

1C. A. Gentile, 1C. Priniski, 2J. Sethian, 1W. Blanchard, 1L. Ciebiera, 1F. Dahlgren, 1G. Gettelfinger, 1S. Langish

1 Princeton Plasma Physics Laboratory 2 Naval Research Laboratory

HAPL Workshop

Oak Ridge National Laboratory

March 21 - 22, 2006

* Please see poster: C. Priniski, et al. on T Collection & Purification

MotivationMotivation• Safe, economical processing is

crucial to the success of fusion energy devices.

• At ≈ $3/Ci - $8/Ci one kg of T cost ≈ $29M - $78M. Perhaps more.

• Processing plasma exhaust has been demonstrated in an operational fusion environment (TFTR, JET).

• Deliver T (and D) back to target manufacturing in a timely manner.

• Closing the fuel loop in IFE reduces external handling (DOT 49 CFR) and burial site issues in support of a lower operational inventory.

Requirement Action

Design a closed loop tritium processing/recycling facility (for ≈ 25 kg/y T throughput) IFE plasma exhaust system

• A conceptual design for such a system is being investigated for required operational parameters

Design a safe, economical system which processes plasma exhaust that will return high purity T and D back to target fueling system with accurate inventory control

• Incorporate COTS components, proven processing technology experience, and safe handling procedures in the CDR

Develop an operational strategy which minimizes at risk tritium for technical and regulatory classification consideration(s)

• All system flows will be analyzed and modeled to maintain inventory at economical levels in support of machine operation. Propose a ramp up (nuclear fuel usage) strategy

Requirements:Requirements:

Estimated Operational ParametersEstimated Operational Parameters

During Full 5 Hz Operation 500 kJ Target Case Per shot Per Day (10 hrs) Per Year (60%)Targets* Grams Percent Grams KgMass D-T Fuel (pre-burn) 0.00050 67.7% 90.02 19.71Mass CH Foam (DVB) 0.00014 19.5% 25.93 5.68Mass CH Coat (PVP) 0.00009 12.8% 17.01 3.72Exhaust*Mass D-T Fuel (unburned) 0.00033 47.3% 60.01 13.14Mass He (ash/decay) 0.00013 18.8% 23.89 5.23Mass CH producrts 0.00024 33.9% 42.94 9.40Blacket OutputMass Tritium 51.4 9.25

Components of Plasma ExhaustComponents of Plasma Exhaust-Hydrogen isotopes (fuel)

-Hydrocarbons (foam, over coating)

-Trace metals (target coating)

-Helium isotopes (decay, ash)

-Nitrogen (in leakage)

-Oxygen (in leakage)

-Argon (in leakage)

-Water (in leakage)

-Other residue from components (walls, blankets, etc.)

Question for target designers - Can protium be eliminated from target components?

Facility CategorizationFacility Categorization• Maintain at risk Tritium Inventory at low levels for

as long as possible (DOE Std 1027, DOE O 5480.23)

– Lower regulatory categorization of facility.– Maintain calculated off-site doses from a credible

accidental release low.– Safety Analysis

Requirements/Reports/Documentation.

Radiological Facility < 16,000 Ci*

Cat. 3 Nuclear Facility ≤ 30 grams

Cat. 2 Nuclear Facility > 30 grams

Cat. 1 Nuclear Facility Std. 1027* No 5480.23 safety analysis report (SAR) required

Path ForwardPath Forward

– Safety Primary Focus - Everything else flows from this position.

– Analyze system flows to ensure a safe and efficient design.

– Model system flows to identify and prevent bottlenecks in system.

– Work with other sub-system groups (blanket, target fabrication) to ensure the T processing system integrates readily into overall project.

– Provide a viable Conceptual Design Review (CDR) of System, employing formal technical Design Review process.

– Investigate regulatory characterization strategy.

ConclusionConclusion

• To date the fusion fuel cycle has been successfully modeled at various laboratories around the world.

• Two facilities have successfully processed plasma exhaust and closed the fusion fuel cycle on site.

• The best experience from the T community including modeled and empirical venues will be integrated into the CDR.

• A strategy driven ramp up plan for T use will be developed to minimize the effects of regulatory compliance and cost.