Coolant circuit design

The first element is technology simplification. All design variants are built on the premise that they share common system technologies to maximum extent possible. As a result, the design variants share a unified reactor and primary coolant circuit, an aerodynamically and mechanically similar line of helium gas turbines used for electricity production, and the IS process selected to produce hydrogen. This paper shows that the helium gas turbine and the IS process are compatible application systems with the high temperature reactor heat source to enable economically competitive energy production. 

Optimizes coolant can eliminate need to chill coolant. Cooling efficiency ensures optimum circuit design. 

The Encapsulated Nuclear Heat Source (ENHS, ANNEX XX) is a modular lead-bismuth cooled reactor of 50-75 MW(e) with a 20-year or even longer refuelling interval. The reference ENHS reactor has two coolant circuits, both being of a pool type the primary coolant circulates inside the ENHS module while the secondary (intermediate) coolant circulates in the pool the ENHS module is inserted in. The reactor design incorporates optimum combinations of reactivity feedbacks and is fissile self-sufficient. 

In the design of the coolant circuit and auxiliary circuits, traps where fluid can stagnate and where activated corrosion products can collect should be... 

Some of the radionuclides present in the coolant as a result of the accident are released from the coolant circuit by coolant leakage. Provision needs to be made in the plant design to collect the leaking coolant by means of a ventilation system and to discharge it to the atmosphere via high efficiency particulate attenuation (HEPA) air filters. 

III-40. For OCRs, the design of the coolant circuit and the automatic shutdown system of the reactor and the design fuel rating need to be such that clad melting will not occur in a depressurization accident. It needs to be noted... 

Despite the large fission product and actinide inventory of the fuel, the leakage rate from the fuel pins may be kept to a very small value by adequate design and careful quality control in manufacture. The coolant circuits of reactors which are refueled on-load are particularly easy to maintain at a low level of activity, on account of the ease with which defective elements can be removed. In addition to any small escape of fission products from cracks or pinholes in the cladding, some activity will generally arise from slight contamination of the outsides of the fuel pins with fuel while they are being loaded. 

In the Winfrith prototsrpe reactor it was important, because of the containment design, to avoid the propagation of a reactor coolant circuit failure which could lead to a larger failure than the containment could handle satisfactorily. Also, and this may apply more critically to other forms of containment, it was particularly important to ensure that a failure in one half of the reactor coolant circuit did not lead to a breach in the otherwise Intact other half of the circuit. 

CDFR is a pool-type SFR with a preliminary designed thermal power of 2100 MW and an electrical power of 870 MW. Mixed oxide (MOX) is used as the fuel, and sodium is the main coolant. The reactor is a three-loop, three-circuit design, and there is only one set of steam turbine generators. Fig. 14.5 shows the preliminary core layout of the CDFR (Yang et al., 2007). It was planned to be constructed in Xiapu, Fujian province, under the cooperation of the China National Nuclear Corporation (CNNC), the Fujian Investment and Development Group, and the Xiapu state-owned assets investment management company with the investigation ratio of 51 40 9. 

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