Radiation and criticality safety analyses for the highly-enriched uranium core removal from a research reactor

Haile Dennis; Charles Grant; John Preston

doi:10.1016/j.apradiso.2017.08.025

Radiation and criticality safety analyses for the highly-enriched uranium core removal from a research reactor

Appl Radiat Isot. 2017 Nov:129:152-155. doi: 10.1016/j.apradiso.2017.08.025. Epub 2017 Aug 31.

Authors

Haile Dennis¹, Charles Grant², John Preston³

Affiliations

¹ International Centre for Environmental and Nuclear Sciences, 2 Anguilla Close, University of the West Indies, Mona, Kingston 7, Jamaica. Electronic address: haile.dennis02@uwimona.edu.jm.
² International Centre for Environmental and Nuclear Sciences, 2 Anguilla Close, University of the West Indies, Mona, Kingston 7, Jamaica. Electronic address: charles.grant@uwimona.edu.jm.
³ International Centre for Environmental and Nuclear Sciences, 2 Anguilla Close, University of the West Indies, Mona, Kingston 7, Jamaica. Electronic address: john.preston@uwimona.edu.jm.

PMID: 28863288
DOI: 10.1016/j.apradiso.2017.08.025

Abstract

Analysis was performed to estimate radiation levels during removal and packaging of the highly-enriched uranium core of the JM-1 SLOWPOKE-2 research reactor. Due to severe limitations of space in and around the reactor pool, the core could not be removed in the conventional manner as was done for previous SLOWPOKE defuelling operations. A transfer shield, with a balance between shielding efficacy, volume and weight was designed. Fuel depletion, Monte Carlo shielding and criticality calculations were performed. Comparisons of measured and calculated dose rates as well as results of the criticality safety assessment are presented. The designed transfer shield reduced the calculated unshielded dose rate from 29Sv/h to 8mSv/h. The maximum calculated effective neutron multiplication factor of approximately 0.89 was below the 0.91 upper subricital limit.

Keywords: Criticality safety; Highly-enriched uranium; Radiation shielding; Research reactor; Spent fuel.