skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Modeling the Multiaxial Strength of H-451 Nuclear Grade Graphite

Journal Article · · Carbon

The core of a prismatic High Temperature Reactor (HTR) is constructed from an array of nuclear graphite components. Similarly, the core of a Pebble Bed HTR is confined by large graphite blocks which define the (annular) core geometry. In both HTR designs the large graphite components act as neutron moderator and reflector as well as providing mechanical support to the active core. During reactor operation the graphite components of the core are subjected to complex stress states. Consequently, core designers need a suitable theory of failure. Both deterministic (e.g., maximum principal stress theory) and probabilistic (e.g., Weibull failure theory) have been considered. To test candidate failure theories a multiaxial testing program was conducted at Oak Ridge National Laboratory on H-451 graphite. Large specimens ({approx}27 cm length) were subjected to combined axial stress (tension and compression) and internal pressure. A total of 59 specimens were tested at 9 stress ratios in the first and fourth stress quadrants. Here, we report the basis and performance of a microstructurally based graphite fracture model and multiaxial strength data for grade H-451 graphite, along with the application of the model to predict the failure envelope for H-451 graphite in the first and fourth multiaxial quadrants.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
Work for Others (WFO)
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
932037
Journal Information:
Carbon, Vol. 47, Issue 13; ISSN 0008-6223
Country of Publication:
United States
Language:
English