Depends on what fuel it is built for, what moderator is used, etc.
For example, a molten salt reactor produces no plutonium that is needed for weapons.
{...
Thorium and uranium reactors use different fission reactions, which means the reactions have different products and properties. Uranium reactors use uranium-235 as their fissile fuel, as well as the plutonium-239 that is produced from the uranium-238 that is also present in the fuel, and this reaction produces enough neutrons to perpetuate the reaction until the fuel is used up or the control rods are used to absorb the neutrons and slow the reaction. [1-3] Not all the plutonium produced by this reaction is broken down, and significant quantities of it remain in the waste. [2,3] In thorium reactors, thorium-232 (the most common isotope naturally found) becomes thorium-233 when it absorbs a neutron, and this unstable isotope decays into protactinium-233 and then quickly into uranium-233, which is the fissile fuel. [2,4] This production of fissile fuel from non-fissile but fertile fuel is called breeding, so the thorium reactor is a type of breeder reactor, with the same risks of instability that are found in uranium-based breeder reactors. [2] However, the fission of uranium-233 doesn't release enough neutrons to perpetuate the reaction, so more neutrons must be pumped into the reactor to keep it going. [2,4,5] Also
unlike the uranium reactor, no plutonium is produced in the thorium reactor, and if plutonium is added to the reaction, it is broken down, becoming a neutron source for the reaction, and does not remain in the waste in significant quantities. [2,3]
...}