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Title: Sensitivity Studies of Air Ingress Acidents in Modular HTGRs

Journal Article · · Nuclear Engineering and Design
 [1];  [2];  [3]
  1. ORNL
  2. General Atomics, San Diego
  3. OKBM, Nizhny Novgorod, Russia

Postulated air ingress accidents, while of very low probability in a modular high-temperature gas-cooled reactor (HTGR), are of considerable interest to the plant designer, operator, and regulator because of the possibility that the core could sustain significant damage under some circumstances. Sensitivity analyses are described that cover a wide spectrum of conditions affecting outcomes of the postulated accident sequences, for both prismatic and pebble-bed core designs. The major factors affecting potential core damage are the size and location of primary system leaks, flow path resistances, the core temperature distribution, and the long-term availability of oxygen in the incoming gas from a confinement building. Typically, all the incoming oxygen entering the core area is consumed within the reactor vessel, so it is more a matter of where, not whether, oxidation occurs. An air ingress model with example scenarios and means for mitigating damage are described. Representative designs of modular HTGRs included here are a 400-MW(th) pebble-bed reactor (PBR), and a 600-MW(th) prismatic-core modular reactor (PMR) design such as the gas-turbine modular helium reactor (GT-MHR).

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:
1031512
Journal Information:
Nuclear Engineering and Design, Vol. 238, Issue 11; ISSN 0029-5493
Country of Publication:
United States
Language:
English