1. Modeling and Analysis of a Representative Fission Product Removal System for a Vented Helium Cooled Fast Reactor Wesley Deason, Saturday, January 26 th, 2013 2013 OSU-ANS Winter Conference

2. Agenda Background Project Purpose Project Methods Current Progress Future Work

3. What is Vented Fuel? Simply the venting of accumulated fission product gases. Why vent? Removes cladding pressure Decreases volatile source term Allows greater control of fission products

4. Historic Vented Fuel Design General Electric: Fast Ceramic Reactor General Atomic: Peach Bottom Unit 1

5. Project Purpose To quantify feasibility and safety. Feasibility – Can it be built for reasonable cost? Is Commercial or Government research required? NRC approval? Construction time? Safety – Is it more safe or less safe than current designs?

6. Current Progress Completed Extensive Literature Review – Previous Reactor Designs PB Unit 1, GCFR, SFR, LMFRB, DFR, EM 2, TID, GFR – Helium Purification System Design Filter/Absorbers, molecular sieves, and cold charcoal beds – Fission Gas Behavior in HTGRs Release Rates from fuel

7. STELLA Modeling Determination of significant fission products – Ignore short lived and low yield fission products

8. STELLA Modeling Development of an accurate and efficient modeling methodology – Ideal: model all significant nuclides together Activation/Depletion due to Neutron Absorption Interdependence due to chemical reactions Parent/Daughter decay chain tracking throughout system

9. STELLA Modeling Development of an accurate and efficient modeling methodology – Compromise: model significant decay chains together Parent daughter decay chain tracking in system Assume activation and depletion of fission products is minimal in fast environment Treat chemical interactions independent from other elements

10. STELLA Modeling

11. Future Work Determination of interaction parameters – Element dependent Filter fractions Leakage fractions Plate-out (adsorption) fractions Development of desired system studies – Tests for meeting project objectives Reach conclusions on system feasibility and safety