TMI-2 (Three Mile Island Unit 2) Ex-Vessel Defueling
As a consequence of the 1979 Three Mile Island Unit 2 (TMI-2) accident, the fuel was severely damaged, and fuel fines and debris were transported throughout the reactor coolant system (RCS). Estimates of the fuel quantities in equipment and piping outside the reactor vessel boundary have been developed based on component-specific methods, such as sampling, remote visual inspections, and gamma spectroscopy. To ensure a safe, stable plant configuration (called postdefueling monitored storage) following the defueling effort, fuel must be removed from any area if the potential for criticality exists. The fuel quantity estimates are, therefore, used as a simple guideline to indicate the potential need to remove fuel from ex-vessel locations. The juxtaposition of multiple fuel containing components is also considered. Systems have been designed to defuel seven specific ex-vessel areas. These are pressurizer, pressurizer spray line, once-through steam generator (OTSG) upper tubesheets, RCS hot legs, decay heat line, RCS cold legs and reactor coolant pumps, and OTSG lower heads and J-legs. Systems and equipment have been developed and used to successfully defuel certain ex-vessel areas of TMI-2. This ex-vessel defueling, along with the completion of in-vessel defueling, will allow TMI-2 to be placed into postdefueling monitored storage.
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
- OSTI ID:
- 5839170
- Report Number(s):
- CONF-881011-; CODEN: TANSA
- Journal Information:
- Transactions of the American Nuclear Society, Vol. 57; Conference: Joint meeting of the European Nuclear Society and the American Nuclear Society , Washington, DC (United States), 30 Oct - 4 Nov 1988; ISSN 0003-018X
- Publisher:
- American Nuclear Society
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
42 ENGINEERING
CORIUM
REMOVAL
REACTOR COOLING SYSTEMS
DECONTAMINATION
THREE MILE ISLAND-2 REACTOR
REACTOR ACCIDENTS
CRITICALITY
FUEL ASSEMBLIES
GAMMA SPECTROSCOPY
HOSES
MELTDOWN
PIPES
PRESSURE VESSELS
PRESSURIZERS
PRIMARY COOLANT CIRCUITS
PUMPS
REACTOR CORE DISRUPTION
REMOTE VIEWING EQUIPMENT
RHR SYSTEMS
SAFETY
SAMPLING
STEAM GENERATORS
STORAGE
VACUUM SYSTEMS
ACCIDENTS
BOILERS
CLEANING
CONTAINERS
COOLING SYSTEMS
ENERGY SYSTEMS
ENRICHED URANIUM REACTORS
EQUIPMENT
POWER REACTORS
PWR TYPE REACTORS
REACTOR COMPONENTS
REACTORS
SPECTROSCOPY
THERMAL REACTORS
VAPOR GENERATORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
Nuclear Criticality Safety Program (NCSP)
Three Mile Island Unit 2 (TMI-2)
Fuel
Reactor Coolant System (RCS)
Postdefueling Monitored Storage
220900* - Nuclear Reactor Technology- Reactor Safety
210200 - Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled