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Title: Accident analysis for the NCSC foil experiment

Journal Article · · Transactions of the American Nuclear Society
OSTI ID:552481
;  [1]
  1. Los Alamos National Lab., NM (United States)

An accident analysis has been performed for the nuclear criticality safety class (NCSC) foil experiment. The Los Alamos Critical Experiments Facility (LACEF) performs this experiment regularly during its 2-, 3-, and 5-day nuclear criticality safety classes. This accident analysis is part of an effort to modify the NCSC foil experiment plan so that the experiment may be operated at delayed critical. Currently, the NCSC foil experiment may only be operated up to a neutron multiplication of 100. The purpose of the accident analysis is to ensure that any accidental nuclear excursion does not exceed the boundary of the safety envelope described in the LACEF safety analysis report (SAR). The experiment consists of very thin, highly enriched (93% {sup 235}U) uranium metal foils (23 X 23 X 0.008 cm) interleaved between Lucite plates (36 X 36 X 1.27 cm). The fuel foils and Lucite plates are stacked vertically to form a critical assembly. Extra Lucite plates placed at the top and bottom of the assembly act as vertical reflectors. The assembly is operated remotely with the use of a general-purpose vertical-lift platform machine. The accident scenario consists of one additional fuel foil being added to an existing critical or nearly critical stack. The reactivity insertion rate is 0.05 $/s, based on the speed of the vertical-lift platform. It is assumed that none of the safety systems will function properly during the accident and that the operating crew is unable to mitigate the accident.

OSTI ID:
552481
Report Number(s):
CONF-971125-; ISSN 0003-018X; TRN: 98:001690
Journal Information:
Transactions of the American Nuclear Society, Vol. 77; Conference: 1997 American Nuclear Society (ANS) winter meeting, Albuquerque, NM (United States), 16-20 Nov 1997; Other Information: PBD: 1997
Country of Publication:
United States
Language:
English