C

Control Rods

¹⁰B + n → ⁷Li + ⁴He
Quick Reference
Formula / Notation¹⁰B + n → ⁷Li + ⁴He
Also Known AsNeutron absorber rods, reactor control rods, absorber rods, SCRAM rods

What is Control Rods?

Control rods are neutron-absorbing rods inserted into a nuclear reactor to regulate the rate of the fission chain reaction. Made of materials with high neutron-absorption cross-sections such as boron, cadmium, or hafnium, they are raised to increase the reaction rate and lowered to decrease it or shut down the reactor. Control rods are essential safety components.

Formula & Notation

¹⁰B + n → ⁷Li + ⁴He

Other Names / Synonyms: Neutron absorber rods, reactor control rods, absorber rods, SCRAM rods

Properties & Characteristics

Control rods are neutron-absorbing rods inserted into a nuclear reactor core to regulate the fission chain reaction by absorbing excess neutrons. Materials used include boron (in boron carbide or boric acid), cadmium, and hafnium, chosen for their high neutron absorption cross-sections. Inserting rods reduces reactivity (subcritical); withdrawing them allows criticality. In SCRAM (emergency shutdown), rods drop fully in to halt the chain reaction.

Uses & Applications

Control rods are essential safety and operational components in all fission nuclear reactors (PWR, BWR, CANDU, research reactors). They allow operators to start up, maintain steady-state, and shut down reactors safely. Their design is critical to reactor safety analysis.

Safety Information

Failure to insert control rods rapidly (as occurred at Chernobyl) can result in catastrophic power excursion. Control rod mechanisms must be fail-safe and regularly inspected. Materials must withstand intense neutron bombardment and heat. Spent control rod materials are radioactive waste.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Control Rods
Formula ¹⁰B + n → ⁷Li + ⁴He
Synonyms Neutron absorber rods, reactor control rods, absorber rods, SCRAM rods

Frequently Asked Questions

Control rods are neutron-absorbing rods inserted into a nuclear reactor to regulate the rate of the fission chain reaction. Made of materials with high neutron-absorption cross-sections such as boron, cadmium, or hafnium, they are raised to increase the reaction rate and lowered to decrease it or shut down the reactor. Control rods are essential safety components.

More "C" Terms

View all "C" terms →
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z