Core blower

FIGURE 61.6 Section through typical core blower. 

To successfully exploit post combustion to eliminate VOCs from off-gases, specific minimum concentrations are necessary. These limit values are compound specific and depend on the chosen technique. Post combustion is possible for the exhaust gas from shell moulding. Generally, the exhaust gas from the casting shop does not have high enough VOC levels to operate post combustion. One alternative to post combustion is to use exhaust air from the core blowers as combustion air for the cupola. 

This blog repaitf on a host ol Issues ossoclotod with research and policy of nonotechnoMgy. tho blower Is or has been a PI or con grants (appwt.t N). opinions expressed here are my own. They should bo NtnwER attributed to nor associated with North core University and the Notional Science Foundation. 

The flow diagram of RVCS is shown in Fig 2 The system consists of a RPV recuperator(RVR), a RPV cooler(RVC), orifices and valves As illustrated in Fig 1 and Fig 2, a bypass flow is extracted from the blower outlet and flows downward through the tube side of the RVR, which is installed in the annular region outside the IHX, and is cooled down from 550t to 250 Then the cold bypass flow enters an annular channel outside the RVR and flows upward into the shell side of a little cooler (RVC) and is cooled form 250°c to 190 t , the 190 c cold gas enters the gap between the RPV and core vessel and is heated by the two vessel from 190 to 220x At last, the 220 X bypass gas flows upward through some vertical pipes and comes into the RVR shell side and returns to the blower inlet The main technical data of the RVCS is given in table 4... 

In case of normal shutdown, the inlet valve of the main blower is closed and all of equipment in the secondary loop stop at the same time. The auxiliary blower of SCS then starts to drive helium flowing through the core, IHX. RVR shell side. RVC, the RVR tube... 

The substantial separation of the reactor core and the steam generator by the shielding concrete walls of the reactor cell makes it possible to repair all defects in the steam generator bundle or the primary circuit blower without accessibility problems. 

This group of characteristics concerns the components of the reactor coolant system that are designed to circulate coolant through the reactor to remove heat from the core. Based on the type of coolant, they include both liquid pumps and gas circulators (blowers). 

The name reflects the basic technology of the concept a fast neutron spectrum, heavy metal lead-bismuth coolant, a high level of natural circulation with a nominal operation of inert gas blowers and safe cooldown of the core after the trip of gas supply blowers. 

For this reason, under of the nominal load, the reactor is operated by reducing the coolant density. This is obtained by recirculating a portion of the steam to the core inlet through a steam blower. The steam flow rate is then established so as to ensure a stable coolant flow in the power channels. 

A Steam cooled fast reactor is defined as one in which the core inlet coolant is steam , not water. Blowers are required for steam cooled reactors instead of reactor coolant pumps. The pumping power of blowers is huge. Some supercritical pressure water cooled reactors have adopted pressure tubes instead of the RPV and have separate moderator and coolant. Indirect cycle reactors with a RPV are also found. 

In 1989, the steam-water power reactor concept was presented by Alekseev and colleagues working in the former USSR [16]. The use of steam-water mixture for the reactor cooling is a key feature of the concept. There are two versions of the steam-water mixture preparation and distribution system. In one, the steam is supplied externally by steam blowers to the RPV and it mixes with feedwater in the special nozzle mixers set at the fuel assembly inlet. In the other, the steam is circulated in the RPV by jet pumps. The steam-water mixture is prepared in the jet pumps. The diagram of the steam-water power reactor is shown in Fig. B.24 [3]. There is no description on the feasibility of steam-water mixture generation. The plant system is indirect cycle. The primary pressure is 16.0 MPa. The core inlet and outlet temperatures are 347 and 360°C, respectively. The core inlet quality is 40%. The average void fraction of the core is estimated to be 93%. The core average coolant density is estimated to be 0.14 g/cm. It should be pointed out that the technical and safety problems will be similar to those of the steam cooled FBR. 

Loeffler-type boiler for generating inlet steam. Steam blowers are required rather than feedwater pumps. Short time margin for emergency core cooling due to high power density and positive reactivity coefficient is an engineering drawback. Appendix B is based on Ref. [3]. 

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