Comparative analysis of gas release from biphasic lithium ceramics pebble beds of various pebbles sizes and content under neutron irradiation conditions oleh Timur Kulsartov, Zhanna Zaurbekova, Regina Knitter, Inesh Kenzhina, Yevgen Chikhray, Asset Shaimerdenov, Saulet Askerbekov, Gunta Kizane, Alexandr Yelishenkov, Timur Zholdybayev