View Single Post
mheslep
#20
Sep2-11, 12:16 PM
PF Gold
P: 3,098
Quote Quote by QuantumPion View Post
It's not an accident problem, it's simply the design of the system.

A gas cooled reactor using the Brayton cycle would still have to have a way to dump decay heat on a trip, which would involve venting gas or steam to the atmosphere.
The issue here, as I think I understand it, is that with the Rankine a condenser is required and that when the condenser stops the system has no way of continuing to transfer heat to the turbine and removing energy (decay heat) from the system. I don't see the need for a condensor in a Brayton. Thus such a system could could continue running turbine at lower power and bleeding off energy after a reactor trip through the normal path.

I don't understand your comment about LWR's not generating high enough temperatures for a Brayton cycle. You may be confusing with rankine cycle with superheated steam, which is true that most LWR's cannot produce superheated steam.
Well IIRC 300K above ambient is typical for an LWR, where as a practical Brayton might run 700K above ambient. And I'm assuming, most likely, He as the gas. Under what trip circumstances He in a Brayton need to be vented?