Civil Engineering Reference
In-Depth Information
- a passive reactor core cooling system
- a passive containment cooling system together with a common heat sink pool
above the inner containment.
These passive heat removal systems provide a backup for residual heat removal
(afterheat) and for heat removal during core melt down situations (Fig.
3.32
)[
23
,
24
].
The large water pool above the inner containment houses an intermediate heat
exchanger (ultimate condenser) with pipe connections down to the wet well part of
the inner containment, into the steam suppression pool and into the cavity below the
pressure vessel.
In a severe accident situation, when the water in the pressure suppression
chamber (wet well) would start to boil, the steam would flow to the heat exchanger
(ultimate condenser) in the upper water pool and condense there. The condensate
would then flow back to the pressure suppression chamber.
In case of reactor pressure vessel bottom melt through by the molten core, the
debris would fall onto the steel plated cavity underneath the reactor pressure vessel.
Openings with fusible valves in the cavity wall would open, water of the pressure
suppression pool would cover the molten core debris and the steam produced would
flow to the heat exchanger (ultimate condenser), condense there and the water
would flow back in the pressure suppression chamber. This water can also be used
for water spray systems in the inner containment to condense steam.
Hydrogen recombiners will lower the hydrogen concentration after a core melt
accident. This will also lower the pressure in the inner containment. Thus, the need
for containment venting in case of overpressure can be avoided [
23
,
24
].
References
1. Kessler G (2012) Sustainable and safe nuclear fission energy. Springer, Heidelberg
2. Cummings WE et al (2013) Westinghouse AP1000 advanced passive plant. In: Proceedings of
ICAPP 2003, Paper 3235, Cordoba, Spain
3. US-APWR Design.
http://www.mnes-us.com/htm/usapwrdesign.htm
4. EPR - European pressurized water reactor, the 1600 MWe reactor.
http://www.areva-np.com/
6. Strasser A et al (2005) Fuel fabrication process handbook. Advanced Nuclear Technology
International, Surahammar
7. G¨ ldner R et al (1999) Contribution of advanced fuel technologies to improved nuclear power
plant operation. In: The Uranium Institute 24th annual symposium, London
8. Czech J et al (1999) European pressurized water reactor: safety objectives and principles. Nucl
Eng Design 187:25-32
9. Foulke L (2011) Safety systems for pressurized water reactors. In: IAEA workshop 2011.
