WP5

Introduction

WP5 targets the assessment of the interaction of ATF clads & joints with the coolant in its various states (water, steam) and with LWR fuels (UO2, MOX) during nominal and transient/accidental operation conditions. Testing activities in WP5 will first assess the resistance of both as-produced and mildly-damaged cladding materials to aqueous corrosion and high-temperature steam oxidation, so as to understand the change in cladding/coolant interaction kinetics with damage evolution and to ensure a more accurate prediction of material performance throughout its lifetime (WP9).

Moreover, WP5 will help to screen the ATF cladding materials & joints prior to neutron irradiation (WP7) by means of two critical screening tests: one in water at 330°C, and one in steam at 1200°C. Select specimens of optimised materials will be ion irradiated in water to assess the synergy of aqueous corrosion with ion irradiation. The test results will drive further material optimization in WP1-WP3 with respect to its resistance to corrosion and/or high-temperature steam oxidation.

Moreover, the compatibility of high-quality ATF clads with standard Gen-II/III LWR fuels (UO2, MOX) will be studied both in inert (helium) & oxidising (steam) atmospheres.

Deliverables

• D5.1: Mid-term assessment of ATF cladding/coolant interaction
• D5.2: Cladding/coolant interaction of proof- of-concept ATF clads/ joints
• D5.3: Interaction of proof-of- concept ATF clads with LWR fuels