Dynamic response of a multielement HTGR core
One of the primary factors in determining the structural integrity and consequently the safety of a High Temperature Gas-Cooled Reactor (HTGR) is the dynamic response of the core when subjected to a seismic excitation. The HTGR core under consideration consists of several thousands of hexagonal elements arranged in vertical stacks containing about eight elements per stack. There are clearance gaps between adjacent elements, which can change substantially due to radiation effects produced during their active lifetime. Surrounding the outer periphery of the core are reflector blocks and restraining spring-pack arrangements which bear against the reactor vessel structure (PCRV). Earthquake input motions to this type of core arrangement will result in multiple impacts between adjacent elements as well as between the reflector blocks and the restraining spring packs. The highly complex nonlinear response associated with the multiple collisions across the clearance gaps and with the spring packs is the subject matter of this paper. Of particular importance is the ability to analyze a complex nonlinear system with gaps by employing a model with a reduced number of masses. This is necessary in order to obtain solutions in a time-frame and at a cost which is not too expensive. In addition the effect of variations in total clearance as well as the initial distribution of clearances between adjacent elements is of primary concern. Both of these aspects of the problem are treated in the present analysis. Finally, by constraining the motion of the reflector blocks, a more realistic description of the dynamic response of the multi-element HTGR core is obtained.
- Research Organization:
- Brookhaven National Lab., Upton, N.Y. (USA)
- DOE Contract Number:
- EY-76-C-02-0016
- OSTI ID:
- 7295810
- Report Number(s):
- BNL-23197; CONF-770929-9; TRN: 77-018920
- Resource Relation:
- Conference: Seminar on HTGR safety technology, Upton, New York, USA, 15 Sep 1977
- Country of Publication:
- United States
- Language:
- English
Similar Records
Non-linear dynamic response of a multi-mass system with gaps
Subharmonic excitation in an HTGR core
Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
HTGR TYPE REACTORS
SEISMIC EFFECTS
MATHEMATICAL MODELS
NONLINEAR PROBLEMS
REACTOR CORES
GAS COOLED REACTORS
GRAPHITE MODERATED REACTORS
REACTOR COMPONENTS
REACTORS
220900* - Nuclear Reactor Technology- Reactor Safety
210300 - Power Reactors
Nonbreeding
Graphite Moderated