HTGR Knowledge Base

Conference Article: Helium storage and control system for the PBMR

Verkerk, E.C. (Integrators of System Technology Ltd, Waterkloof (South Africa))

Abstract

The power conversion unit will convert the heat energy in the reactor core to electrical power. The direct-closed cycle recuperated Brayton Cycle employed for this concept consists of a primary helium cycle with helium powered turbo compressors and a power turbine. The helium is actively cooled with water before the compression stages. A recuperator is used to preheat the helium before entering the core. The start of the direct cycle is initiated by a mass flow from the helium inventory and control system via a jet pump. When the PBMR is connected to the grid, changes in power demand can be followed by changing the helium flow and pressure inside the primary loop. Small rapid adjustments can be performed without changing the helium inventory of the primary loop. The stator blade settings on the turbines and compressors are adjustable and it is possible to bypass reactor and turbine. This temporarily reduces the efficiency at which the power conversion unit is operating. Larger or long term adjustments require storage or addition of helium in order to maintain a sufficient level of efficiency in the power conversion unit. The helium will be temporarily stored in high pressure tanks. After a rise in power demand it will be injected back into the system. Some possibilities how to store the helium are presented in this paper. The change of helium inventory will cause transients in the primary helium loop in order to acquire the desired power level. At this stage, it seems that the change of helium inventory does not strongly effect the stability of the power conversion unit.

view the full text of this article (9 pages, format: PDF, size= 444kB)

key words: Gas Cooled Reactor, Nuclear Technology
Reference:
Technical committee meeting on high temperature gas cooled reactor technology development. Johannesburg (South Africa). 13-15 Nov 1996.
International Atomic Energy Agency, Vienna (Austria)
IAEA-TECDOC--988, pp:195-203