MHTGR licensing approach and plant response to off normal events

Conference · Wed Oct 01 04:00:00 EDT 1986

OSTI ID:7173227

Neylan, A J; Silady, F A

The MHTGR design meets stringent top-level regulatory and user safety requirements that require that the normal and off-normal operation of the plant not disturb the public's day-to-day activities. Quantitative, generic top-level regulatory criteria have been specified from US NRC and EPA sources to guide the design. A probabilistic risk assessment has been utilized to select licensing basis events that cover a wide spectrum of events. The MHTGR fuel has been designed to limit the primary circuit activities to levels that, even if completely released, are within those allowed by 10CFR100. The focus of the safety approach has then been centered on retaining the radionuclide inventory within the fuel by removing core heat, controlling chemical attack, and by controlling heat generation. The core geometry, core power, core power density, heat removal geometry, and heat sinks are designed to provide passive core temperatures during accidents. To limit the potential for chemical attack of the MHTGR core, the primary coolant boundary is designed to make large ingress of air and water very unlikely. Furthermore, the fuel particle coatings are highly impervious to oxidizing agents that do enter the primary coolant. The core heat generation is controlled by the large negative temperature coefficient and by insertion of control material to maintain a subcritical core configuration during the span of the accidents.

• Research Organization: General Atomics Co., San Diego, CA (USA)
• DOE Contract Number: AC03-84SF11963
• OSTI ID: 7173227
• Report Number(s): GA-A-18643; CONF-8610160-3; ON: DE87001317
• Country of Publication: United States
• Language: English

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ACCIDENTS
CARBON
ELEMENTAL MINERALS
ELEMENTS
ENERGY TRANSFER
GAS COOLED REACTORS
GRAPHITE
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OPERATION
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR CORES
REACTOR LICENSING
REACTOR OPERATION
REACTOR SAFETY
REACTORS
RISK ASSESSMENT
SAFETY
TRANSIENTS