4/19/2024 0 Comments Artistic licence physics![]() ![]() A core for a nuclear weapon needs a near-spherical shape for any kind of runaway chain reaction, and depending on size and material may also need a neutron reflector. A nuclear reactor simply cannot cause a full-scale nuclear explosion: fuel assemblies are arranged into long, thin columns separated by cladding the large surface area causes a significant percentage of the available fission neutrons to dissipate into the moderator rather than causing further fission events, preventing a critical mass from forming. Similarly, fictional nuclear reactors will meltdown or go up in gigantic nuclear explosions at the slightest thing going wrong. ![]() This is why most of Japan's nuclear reactors shut down safely during the 2011 earthquake, as the failsafes for their SCRAM systems kicked in (or were activated from the control room) at the appropriate time. If the power to the safety systems is interrupted even for a moment, the mechanism stops resisting and the reactor shuts down. Usually, the SCRAM mechanism has to actively prevent the shutdown from happening - for instance, by constantly pushing against a spring, or holding up control rods with an electromagnet. What's more, even the failsafe have "dead-man" failsafes. A switch that usually exists in multiple redundant locations both near and far away from the reactor room, so that you can always reach at least one during an emergency. This is as opposed to real life, where it's typically an automatic safety feature which engages if the reactor shifts outside a certain set of safe operating parameters and where a manual reactor SCRAM is as simple as turning a switch.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |