Describe the fuel design of the SSR-W
molten salt fuel within vented fuel pins
fuel tube made of zirconium metal cladding
gas vents at the top of the fuel pin to allow gaseous fission products into coolant salt to get captured
tie bar which keep the geometry stable and provide structural support
what is the fuel composition of the SSR-W fuel
45% KCl and 55% actinide trichlorides and lanthanide trichlorides
how is fuel made for the SSR-W fuel design
converts actinide oxides from spent fuel into actinide chloride fuel, without any separation, as a liquid mixture
Advantages of the chloride-cooled molten salt reactor (SSR-W)
- Ability to use waste as fuel through WATSS process, closing the fuel cycle (burns TRUs, recycled fuel also provides no need for fuel enrichment)
- Grid energy storage enhancing grid stability (high output temperature, more efficient electricity generation)
- Reactor crane to refuel the reactor while in operation
- Proliferation resistant
Disadvantages of the chloride-cooled molten salt reactor (SSR-W)
- Corrosion of structural materials poses challenges
- Unwanted chloride isotope production(Cl-36)
- chemistry control and management complexity
- Less mature technology than fluoride
Which are more corrosive, chloride salts or fluoride?
chloride salts, so the SSR-W requires advanced materials which can be expensive
what does MSRE stand for
Fluoride-cooled molten salt reactor
What is the composition of the fuel salt for the MSRE (fluoride-cooled molten salt reactor)
Li + Be + Zr + U
what is the composition of the cooling salt for the MRSE (fluoride-cooled molten salt reactor)
Li + Be
MRSE (fluoride-cooled molten salt reactor): ______ is chemically compatible with the ________ salts and effectively absorbs heat, allowing for efficient temperature control
graphite
fluoride
Advantages of the MRSE (fluoride-cooled molten salt reactor)
- Uses LEU (5%) - doesn’t need HALEU to start the reactor
- high temp increases the efficiency of heat transfer
- low pressure ensure safer operation reducing the size and cost
- online refueling
- self regulating core (negative temperature feedback) fuel expands and becomes less radioactive
Disadvantages of the MRSE (fluoride-cooled molten salt reactor)
- Graphite life span is short (7 years)
- Fuel flowing out the reactor emit delayed neutrons
- Fuel is limited to chemical processes rather than the need to manufacture fuel rods assemblies or tubes
- Corrosion in reactor circuit structures, pipes, valves, and pumps.
- Handling beryllium is difficult (carcinogenic)
- Production of H3 when Li is used
what type of reactor is BREST referring to
lead-cooled fast reactor
Molten lead vs. lead bismuth
Lead:
Bad: High melting point
Good: Chemically inert, no polonium production
Lead bismuth:
Bad: More corrosive and polonium production
Good: Low melting point
For the BREST-OD-300 (lead-cooled fast reactor) what are the primary components within the large vessel filled with molten lead
the core, coolant, and steam generators
what pressure does the coolant of the BREST-OD-300 (lead-cooled fast reactor) operate at
atmospheric pressure because the lead was a really high boiling point, eliminating the need for thick high pressure primary piping
Where does the core sit in the BREST-OD-300 (lead-cooled fast reactor)
at the bottom of the vessel
the geometry of the BREST-OD-300 enables …
natural circulation (even without umps, the density differences between hot and cold lead can sustain decay heat removal)
Describe the process that occurs within the BREST-OD-300 (lead-cooled fast reactor)
The core sits at the bottom of the vessel. Hot lead rises upward through the fuel assemblies into the upper plenum, then flows through vertically arranged steam generator modules. After giving up heat to the secondary side, the cooled lead travels down the outer annulus, the downcomer and reenters the lower plenum.
advantages of Brest (lead-cooled fast reactor)
- Primary system: operates at a low pressure
- Coolant: no sodium water reactions
- Thermal properties: High thermal inertia
- Decay Heat removal: Passive and time limited
- Fuel Cycle: Fast spectrum
- Fuel properties: High conductivity and high metal density
- Steam generators: Internal SGs simplify system
Disadvantages of Brest (lead-cooled fast reactor)
1.Primary system: lead corrosion
2. Coolant: High freezing point
3. Thermal properties: Lower heat transfer coefficient
4. Decay heat removal: Heavy coolant
5. Fuel Cycle: Complex and expensive nitride fuel
6. Fuel properties: Pyroprocessing
7. Internal SGs complicate maintenance
Which reactor uses nitride fuel and closed fuel cycle
(lead-cooled fast reactor) Brest
Whuch reactor has internal steam generators + low pressure operation and passive, time unlimited decay heat removal
Brest (lead-cooled fast reactor)
which reactor uses light water for cooling and moderation then has a heavy water reflector surrounding the core, significantly boosting thermal neutron flux at target positions
MAPLE
