Burn-up characteristics and criticality effect of impurities in the graphite structure of a commercial-scale prismatic HTGR

According to the results, the criticality of the commercial-scale HTGR is unaffected by the impurity levels (even in the un-purified grade IG-11) because the impurities burn cleanly until the End of Cycle (EOC). Therefore, the economy of electricity generation by HTGRs can be improved by using the un-purified grade IG-11 instead of the fine purified grade graphite IG-110.