TMI-2 (Three Mile Island Unit 2) Ex-Vessel Defueling

Conference · Sun Oct 30 04:00:00 EST 1988 · Transactions of the American Nuclear Society

OSTI ID:5839170

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-
• Conference Information: Journal Name: Transactions of the American Nuclear Society Journal Volume: 57
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200 -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
42 ENGINEERING
ACCIDENTS
BOILERS
CLEANING
CONTAINERS
COOLING SYSTEMS
CORIUM
CRITICALITY
DECONTAMINATION
ENERGY SYSTEMS
ENRICHED URANIUM REACTORS
EQUIPMENT
FUEL ASSEMBLIES
Fuel
GAMMA SPECTROSCOPY
HOSES
MELTDOWN
Nuclear Criticality Safety Program (NCSP)
PIPES
POWER REACTORS
PRESSURE VESSELS
PRESSURIZERS
PRIMARY COOLANT CIRCUITS
PUMPS
PWR TYPE REACTORS
Postdefueling Monitored Storage
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR CORE DISRUPTION
REACTORS
REMOTE VIEWING EQUIPMENT
REMOVAL
RHR SYSTEMS
Reactor Coolant System (RCS)
SAFETY
SAMPLING
SPECTROSCOPY
STEAM GENERATORS
STORAGE
THERMAL REACTORS
THREE MILE ISLAND-2 REACTOR
Three Mile Island Unit 2 (TMI-2)
VACUUM SYSTEMS
VAPOR GENERATORS
WATER COOLED REACTORS
WATER MODERATED REACTORS