Mitigation of countercurrent flow limiting at the core outlet during a LOCA

Conference · Thu Jan 01 04:00:00 EST 1987 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:6942589

Hatamiya, S; Murase, M

During postulated loss-of-coolant accidents (LOCAs) in light water reactors, the emergency coolant injected into the upper plenum is opposed by ascending steam generated in the core and lower plenum, resulting in a situation where the amount of water entering the core is limited by the ascending steam at the upper tie plates in a boiling water reactor (BWR), or at the end boxes in a pressurized water reactor with the upper plenum emergency core cooling injection system. This is termed countercurrent flow limiting (CCFL). In high-conversion reactors with narrow flow areas in the core, the ascending steam velocity increases and the velocity of water falling into the core decreases. Therefore, as one method to mitigate CCFL and increase the safety margin, downflow acceleration tubes with a restricted bottom end have been developed. In this paper, the authors investigate the tube characteristics experimentally and analytically.

• OSTI ID: 6942589
• Report Number(s): CONF-8711195-
• Conference Information: Journal Name: Trans. Am. Nucl. Soc.; (United States) Journal Volume: 55
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100 -- Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
210200 -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
BWR TYPE REACTORS
COUNTER CURRENT
ECCS
ENERGY TRANSFER
ENGINEERED SAFETY SYSTEMS
FLUID MECHANICS
HEAT TRANSFER
HYDRAULICS
LOSS OF COOLANT
MECHANICS
PWR TYPE REACTORS
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR CORES
REACTOR PROTECTION SYSTEMS
REACTOR SAFETY
REACTORS
SAFETY
STEAM
TUBES
WATER COOLED REACTORS
WATER MODERATED REACTORS