Nuclear Production of Hydrogen, Fourth Information Exchange ...

PROPOSED CHEMICAL PLANT INITIATED ACCIDENT SCENARIOS IN A S-I CYCLE PLANT COUPLED TO A PEBBLE BED MODULAR REACTOR
Figure 6: Section 2 product flow failure
Figure 7: Section 3 product flow failure
Reaction chamber rupture scenarios
Reaction chamber rupture
In the reaction chamber rupture scenario a single reaction chamber ruptures, causing a breach of
reactants and heat. Due to the pressures involved, the initial result of this accident scenario would be
the critical flow of various reactants out of the reaction chamber. The immediate consequence of such
a scenario would be the loss of the reaction heat sink in a single section. This scenario is interesting,
because depending on the size of the reaction chamber, the degree of parallelisation of the chemical
plant and the size of the break, the consequences and time scale of the accident could vary greatly.
It is also noteworthy that heat is still being added to this system while mass is being lost. The relevant
scenarios are displayed in Figures 8 and 9.
• Reactants flow out of reaction chamber, slowing the reaction rate.
• Flashing liquids in the pre-heater?
• Heat is still being added, mass is being lost.
382 NUCLEAR PRODUCTION OF HYDROGEN – © OECD/NEA 2010