Reactor Cooling-air System

A schematic diagram,of the reactor cooling-air system is shown by Fig. 8.1.A. The description of the system will in general.follow the air flow path, starting with the inlet air. filters-.a.t. the. reactor faces and ending with the stack. .-iv-.  

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In the separation of the major systems of control and instrumentation for the reactor and.the reactor heat removal processes, two major control and instrument centers are provided. These major control centers are located in the Reactor Building and in the Process Water Building. The reactor is controlled from the former, while the latter center, which is primarily for the control and instrumentation of process-water flow through the reactor, includes the instrumentation of the locally controlled reactor cooling-air system. A number of the supporting process systems are like the cooling-air system in that they have- locally controlled equipment but have some instrumentation extended to one or both of the major control centers. 

Air Plow Data. The reactor is. designed for normal Operation at a power level of 30,000 kw. The design aii flow of -2000 Ib/min and pressure drop of 55 in. of water through the reactor cooling-air system are based on maximum temperatures of 570°F in the graphite pebble bed and 500°F in the permanent graphite at 45,0OO- kw operation of the reactor. The. .2000-lb/niin... 

In the.first considerations of the radioactivity problem of the MTR. cooiing- air system, a filter design similar to that used for- the pile at ORNL was included in the exhaust side of the system. Further consideration of the problem along with economy measures prompted omission of the filters in the exhaust side of the reactor cooling-air system. 

Air Ducts and Plenum Chamber. The underground duct of the reactor cooling-air, system enters the building at the north end of the west wall. This duct connects to a plenum chamber beneath the reactor air system blower... 

The propelling force starts at the pressure produced by the vacuum in the reactor cooling air system. A constant supply of air into the chamber increases the pressure behind the shuttle and drives it to the center of the... 

In general, the indicating and recording instruments on the panel are associated with the principal processes, i..e., the process-water and cooling-air systems of the reactor. Some of these instruments and a number of the annunciators are associated with the supporting processes and the effluent control systems. 

Activity of Stuck Guscb. The activity in the stack gases due to air from the contaminated-air system will generally be negligible compared to that due to the.air from the reactor. Thus the design of the stack is based principally on.the radioactivity of the reactor-cooling air. 

Prior to delivery of a shuttle to the reactor, the pneumatic shuttle system is under a slight vacuum since the. solenoid valves at the ends of the shuttle tube are open to the reactor cooling-air exhaust system. The sequence of operations that take place d li ing delivery of a shuttle can be better understood by reference to Fig. A9.B. 

Sample Introduction and Transfer System. The sample Introduction and sample transfer system is a lengthened version of the PHI Model 15-720B Introduction system which consists of a polymer bellows-covered heating and cooling probe, a transferable sample holder, an eight-port dual-axis cross, and the mlnlreactor Interface port and transfer probe (Figure 2). There Is also a transfer vessel port with the necessary transfer probe for Introduction of air sensitive samples. They are not part of the reactor/surface analysis system. The dual cross and attached hardware are supported by the probe drive mechanism which floats on a block driven vertically and transversely by two micrometers. These micrometers plus the probe drive mechanism allow X-Y-2... 

In an open sorption storage system air is transporting water vapor and heat in and out of the packed bed of solid adsorbents (see Figure 235) or a reactor where the air is in contact with a liquid desiccant. In desorption mode a hot air stream enters the packed bed or the reactor, desorbs the water from the adsorbent or the salt solution and exits the bed cooler and saturated. In adsorption mode the previously humidified, cool air enters the desorbed packed bed or the... 

As mentioned before, this system operates at low temperatures. A furnace around the reactor is used to heat the system to the desired temperature. The temperature is measured by an Omega K-type thermocouple that is attached to the outside of the reactor near the catalyst bed. The temperature measured on the outside has been calibrated against the internal temperature of the reactor, and has been discussed elsewhere (Liu, et al. 1996 Marafee, et al. 1997). However, when the operating temperature is below 373 K it is necessary to use cooling air to control the temperature since the plasma itself does heat the... 

A schematic diagram of a prill tower is given in Fig. 7.7. Some details of an installation for fertilizer materials are listed in Table 1.2. Melt is provided to the prilling devices at the top of the tower from reactor/evaporator systems in the case of a fertilizer material such as ammonium nitrate or from a melt tank in the case of fusible materials such as petroleum wax and coal tar pitch. Melt droplets travel counter-current to cooling air and the solid prills are conveyed away from the bottom of the tower to appropriate downstream treatments such as cooling, clay treatment and storage. 

In case off-site power is available, the decay heat is removed through normal heat transport path of secondary sodium and water/steam circuits. Additionally, an independent safety grade passive direct reactor cooling system consisting of 4 independent circuits of 6 MWt nominal capacity each has been provided. Each of these circuits comprises of one sodium to sodium heat exchanger dipped in reactor hot pool, one sodium to air heat... 

The tsunami then overwhelmed the facihty s inadequate 5.5 meter seawall and, most important from a process safety point of view, it knocked out the safety systems designed to keep the reactors cool. Consequently the cores of the reactors overheated leading to partial meltdowns and follow-on problems, such as the generation of hydrogen gas that exploded. A considerable amount of radioactive material leaked to the ground, the sea, and the air— and those leaks appear to be ongoing. 

Fissile element enrichment is 90%. Updating of the reactor took place from 1971 to 1973 and from 1979 to 1983. The first redesign completed in 1973 envisaged increase of the reactor power up to 10 MW, and so it was titled BR-10. However, because of some problems related to reactor vessel air cooling system reactor power was limited to 8 MW level. 

Air Cooling. The thermal shield and the graphite. are cooled by air drawn through them from the Reactor Building. The amount of heat that, must be removed is.indicated in Chap. 4 the external air system to provide proper air flow is described in Chap. 8. ... 

Introduction. The Blower and Fan House contains the blowers and fans for the reactor-cooling- and contaminated-air systems along with their associated equipment. The equipment, function, and some phases of operation have already been discussed in Sections 8 1 and 8-2. The present section describes the general layout of the building equipment. 

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