Ex-core water-level monitor: comparison of computations with LOFT data

Conference · Wed Jan 01 04:00:00 EST 1986 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:6993036

Markoff, D; DeVolpi, A; Prussin, S

The unambiguous, easy-to-interpret indication of inadequate core cooling throughout a reactor vessel is considered important to plant safety function. After the Three Mile Island-2 incident, research was undertaken on a variety of means to monitor coolant inventory. However, questions of survivability and uniqueness of response remain, resulting in continued exploration of ex-core methods. This paper reports on a water-level instrument that is situated outside the reactor vessel and is designed to give separate information on the core and downcomer levels at full power and long after scram. An axial array of gamma detectors has been proposed for this application. The apparatus concentrates on detection of high-energy gamma rays produced by neutron capture in hydrogen and steel. Under these conditions, it would be possible to monitor the coolant level from outside the pressure vessel and therefore be survivable under accident conditions; it would not need vessel penetrations, nor would maintenance requirements be excessive. By concentrating on the high-energy gamma rays and by collimating the detectors, background would be reduced. The collimation also permits separate monitoring of downcomer and core liquid-level conditions and allows vertical resolution of coolant inventory and density over the full vessel height.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 6993036
• Report Number(s): CONF-861102-
• Conference Information: Journal Name: Trans. Am. Nucl. Soc.; (United States) Journal Volume: 53
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
ALLOYS
CAPTURE
COMPUTER CODES
CONTAINERS
COOLING SYSTEMS
DETECTION
ELEMENTS
ENERGY SYSTEMS
GAMMA DETECTION
HYDROGEN
HYDROGEN COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
LEVEL INDICATORS
LOFT REACTOR
LOSS OF COOLANT
MAINTENANCE
MEASURING INSTRUMENTS
NONMETALS
O CODES
ONE-DIMENSIONAL CALCULATIONS
OPERATION
OXYGEN COMPOUNDS
PRESSURE VESSELS
PRIMARY COOLANT CIRCUITS
PWR TYPE REACTORS
RADIATION DETECTION
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR MAINTENANCE
REACTOR OPERATION
REACTOR SAFETY EXPERIMENTS
REACTOR SHUTDOWN
REACTORS
RESEARCH AND TEST REACTORS
RESEARCH PROGRAMS
SCRAM
SHUTDOWNS
SIMULATION
STEELS
TANK TYPE REACTORS
TEST REACTORS
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS