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U.S. Department of Energy
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Ex-Vessel Defueling for TMI-2

Conference · · Transactions of the American Nuclear Society
OSTI ID:5578362

As a consequence of the Three Mile Island Unit 2 (TMI-2) accident, the fuel was severely damaged, and fuel fines and fuel rubble were transported throughout the reactor coolant system (RCS) and to other systems connected to the RCS. Estimates of the quantity of fuel in equipment and piping outside the reactor vessel boundary have been developed based on component specific methods, such as sampling, monitoring by camera, and gamma spectroscopy. To ensure a safe, stable plant configuration during the postdefueling monitored storage (PDMS) phase, fuel must be removed from any area if the potential for criticality exists. The fuel quantity estimate is therefore used as a simple guideline to indicate potential need to removal fuel from ex-vessel locations. The juxtaposition of multiple fuel containing components is also considered. Components that have been considered as candidates for possible fuel removal are shown, and their estimated fuel quantities are listed. Three systems have been designed to defuel three specific ex-vessel areas: the pressurizer defueling system, the pressurizer spray line defueling system, and the plenum defueling system.

Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
OSTI ID:
5578362
Report Number(s):
CONF-870601-
Journal Information:
Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 54; ISSN TANSA; ISSN 0003-018X
Publisher:
American Nuclear Society
Country of Publication:
United States
Language:
English