Technical Details


Indirect cycle – 3 different modules for the secondary circuit

Double containment for physical protection and as a barrier for release of radionuclides

Partially underground facility – a maximum height only 18 m above ground

5 years of continuous operation without refuelling

Fully passive

Major Technical Details


Reactor Type

High Temperature reactor pool type

Technology

Gas-cooled Fast Reactor (GFR)

Primary Coolant

He

Thermal capacity
0MW(t)
Secondary Coolant

N2+He

Primary Circuit Pressure

7.5 MPa

Core Inlet/Outlet Coolant Temperature

450 / 900 °C

Secondary Circuit Pressure

8.0 MPa

Fuel type

UC or (U, Pu) C

UC Fuel Enrichment

19,5 %

(U, Pu) C Fuel Enrichment

30 %

Operation Time without outage
0months
Load factor
>0%

Current R&D Challenges


The highest priority in GFR R&D must be assigned to areas unique for the technology, where there is a limited or even no possibility to adopt or adapt existing and proven solutions. Many obvious synergies exist between VHTR and GFR, such as the same type of coolant with very similar target primary temperatures and pressure. So, a lot of solutions working for HTR in normal operation, such as sealing, valves and blowers, can be utilized in GFR as well.

However, in accident conditions, behaviour of the two systems is very different. HTR can rely on cooling using conduction and radiation, and its huge mass of graphite in the core providing substantial heat sink. For a compact core of GFR, it is necessary to employ specialized systems ensuring constant and sufficient flow of coolant through the core. To find technical solutions to this problem that would not put the overall economic feasibility of the technology at risk is one of the primary goals of R&D activities on GFR.

Another topic specific to GFR is the fuel and core materials in general. Combination of very high temperatures and fast spectrum of neutrons puts very high demands on the used materials. Development of this area had been long rather slow, however, after the Fukushima accident, the boom in development of so-called ATF (accident tolerant fuel materials) is favourable also for GFR, especially in SiC composites.