Strain-based safety evaluations of nuclear spent-fuel transport casks in drop events

Abstract

This paper comparatively evaluates stress-based and strain-based acceptance criteria that are suggested in ASME Section III. Parallel and vertical accidents drop (9 m drop) tests were performed. Finite Element Analysis (FEA) was performed to evaluate accidental drop events which were specified in NUREG-1536. Basket and canister which contain NSF were evaluated during events, and structural safety was investigated for stress-based criteria and strain-based criteria by comparing FEA results with design acceptance results. In all cases, basket and canister predominantly excess yield strain, however, did not reach acceptance strain. Compare with horizontal drop and vetical drop, horizontal drop has high value in basket, and vertical drop has high value in canister. Also in strain-based design criteria, the highest maximum safety ratio was 0.27 and there had 73% of margin to reach design lite strain