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Title: MORECA: A computer code for simulating modular high-temperature gas-cooled reactor core heatup accidents

Technical Report ·
DOI:https://doi.org/10.2172/5955421· OSTI ID:5955421
 [1]
  1. Oak Ridge National Lab., TN (United States)

The design features of the modular high-temperature gas-cooled reactor (MHTGR) have the potential to make it essentially invulnerable to damage from postulated core heatup accidents. This report describes the ORNL MORECA code, which was developed for analyzing postulated long-term core heatup scenarios for which active cooling systems used to remove afterheat following the accidents can be assumed to the unavailable. Simulations of long-term loss-of-forced-convection accidents, both with and without depressurization of the primary coolant, have shown that maximum core temperatures stay below the point at which any significant fuel failures and fission product releases are expected. Sensitivity studies also have been done to determine the effects of errors in the predictions due both to uncertainties in the modeling and to the assumptions about operational parameters. MORECA models the US Department of Energy reference design of a standard MHTGR.

Research Organization:
US Nuclear Regulatory Commission (NRC), Washington, DC (United States). Div. of Regulatory Applications; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USNRC; Nuclear Regulatory Commission, Washington, DC (United States)
DOE Contract Number:
AC05-84OR21400
OSTI ID:
5955421
Report Number(s):
NUREG/CR-5712; ORNL/TM-11823; ON: TI92003495
Country of Publication:
United States
Language:
English