Investigation of the control rod material presence in the Three Mile Island-2 lower head

This paper is a follow-up study on the determination of the material distribution in the Three Mile Island Unit 2 (TMI-2) lower head. In a previous study, the authors analyzed the data obtained by a gamma detector inserted in the L-11 guide tube of the TMI-2 reactor lower head. The detector response was computed based on the adjoint function concept. The present study complements the previous study and suggests that it is reasonable to expect that there is a layer of CR materials at the bottom of the TMI-2 lower head in the vicinity of the L-11 guide tube. This conclusion is in agreement with the previous studies, which were based on other types of analyses