b'3.4 STATUS AND PROJECTIONSStatus and Projections for Conclusion of the Long-RunningAFC Series Irradiations Principal Investigator: Nicolas Woolstenhulme, INLTeam Members/ Collaborators: Randy Fielding, Bryon Curnutt, Colby Jensen, Chris Murdock, Doug Porter, Dan Chapman and Brian GrossThe long-running AFCT he AFC series of irradiationations have been divided into 4 major tests have long been underwaycampaigns to date (AFC-1 through irradiations have madeat the Advanced Test Reactor-4) with several sub-campaigns (e.g. numerous advances(ATR). This test series has addressedAFC-4A, -4B, etc.). Some rodlets can in the understandingnumerous research and developmenttake several years to achieve burnup of fuel performanceneeds for many of the key benefittargets. As a result, sub-campaigns and thus paved theareas of advanced fuels, especiallytypically represent a new batch of way for a new era ofin fast reactor application, includingrodlets shuffled into the irradiation future advanced fuelactinide transmutation, fuel utiliza- positions during reactor outages. New developments. tion through ultra-high burnup fuels,sub-campaigns often corresponded and direct disposal once-throughwith fabrication developments, sharp-metallic fuel systems. The AFC testened research focus areas resulting series began just after the turn offrom Post Irradiation Exams (PIE), the millennium and have proceededand other refinements based on input in a continuous program for nearlyfrom collaborators partners.20 years to the present day. In 2020The AFC-1 and -2 irradiations are now unexpected shortfalls in funding,complete and successfully addressed combined with the advent of newresearch needs for several fuel approaches to accelerated irradiationcompositions including both metallic testing and final preparations for aand ceramic fuels types showing the beryllium replacement long outagerelative insensitivity of fuel perfor-at ATR, have set the backdrop formance when adding actinides. The retiring the workhorse AFC seriesAFC-3 and -4 campaigns have focused irradiations. This summary describeson advanced metallic fuels focusing the background, current state, andlargely on two objectives including projections for completion of thefuel designs able to 1) perform remaining AFC irradiation specimens. well without fuel-to-cladding bond Project Description sodium (thus enabling direct disposal The AFC tests approximate fast reactorfuel cycles) and 2) mitigate the life-test conditions in ATR by placing fuellimiting phenomena associated with rodlets in capsules with gas gaps tofuel cladding chemical interaction elevate specimen temperature while(FCCI). The former of these objectives surrounding them with cadmium tohas focused development on the use filter thermal neutrons. The AFC irradi- of annular fuel geometries in close 138 2020|AFC ACCOMPLISHMENTS'