Dump systems

Dump Systems For an inhibitor injection or quench system, the inhibitor or quenching medium is transferred from an external supply to the reactive material in a dump system, the reactive material is transferred from the storage/handling facility to a safer location that is the same size or, more commonly, larger than the normal capacity of the facility. This allows depressurizing and deinventory of the reacting mass from the facility in an out-of-control situation, such as an incipient runaway reaction. 

The Boyle method (see A5.13) can be used to estimate the diameter required for a dump system. It will usually be safe to assume liquid-only flow if dumping occurs well before the maximum rate (the original Boyle method). Alternatively, the conservative assumption that a homogeneous two-phase mixture (rather than liquid alone) enters the dump system from the reactor could be made (the modified Boyle method). 

Potential gas blowby through the upstream vessel dump system could create too much backpressure in an atmospheric vent system... 

Dump systems to divert reactants to a safer location, such as catch-tanks or quench tanks ... 

A reactor for a nitration reaction is located inside a haU, which has three doors for entry and exit. The reactor is cooled and disposes of an emergency shutdown and dump system. The material factor is MF = 40. 

Is an emergency dump system needed If already in place, is it adequate ... 

A pencil-size neutron source, 0.22 gm RaBe, was placed between the fuel rods at the center of the lattice during approach measurements. Three BF, counters were used to monitor the neutron multiplication. Two safety channels with control and trip circuits from the TTR were used in conjunction with lour safety and two control rods for each experiment. A fast water-moderator dump system was also provided. 

The system is basically similar to many existing liquid systems. The core vessel accommodates cores up to 5 ft. in diameter by S ft. tall and a wide variety of grid structures. A moderator dump system and separate storage is employed. Heating and insulation allow operation up to a tenqmrature of 600 F. Poison rods are cable actuated and can be used in any lattice position. 

Water from the dump system is conducted uncooled to the quench tank or diverted directly to the river. 

The eapability to aceept ramp load changes at 5 -percent power per minute while operating in the range of 15-pereent to 100-percent of full power without reactor trip or steam dump system actuation, subject to core power distribution limits. 

When in use as a compact critical assembly, emergency shutdown is provided by a rapid internal dump system which is ideally suited for the study of close packed cores where the provision of control rods involves an unacceptable perturbation of the core. 

When a fault arises disconnecting the turbo-alternator from the grid, the turbine stop valve is closed rapidly and at the same time a valve opens the dump system, which by-passes the turbine, to the condenser. This dump line Includes a control valve similar to the turbine contrpl valve which can also be ganged electrically to the speeder gear or preset manually to any position, say 100 open. When the turbine stop valve shuts, the pressure error signal is switched to control the dump control valve so that excessive change In pressure is avoided and pressure control maintained. 

During start-up, before the turbine is synchronized, pressu-re.is controlled by the same dump system eithel automatically or manually. As steam Is passed to the turbine by opening its valve manually the dump valve must start to close to maintain pressure. Auto-control of pressure is switched onto the turbine valve as soon as possible and the dump valve closed manually, which causes the turbine valve to open and Increase its loading. 

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