BWRs and PWRs have what to remove hydrogen from containment?

• A. Filtration to remove particulates
• B. Spray to remove water
• C. Ventilation fans to remove oxygen
• D. Hydrogen recombiners to remove hydrogen

Answer: (D)

Hydrogen buildup inside containment is a safety concern after certain transients, so plants use a mechanism that actively removes hydrogen from the gas mixture. Hydrogen recombiners catalytically combine hydrogen with oxygen to form water vapor, reducing the hydrogen concentration automatically and keeping it well below flammable limits. This approach is preferred because it directly lowers hydrogen levels rather than just diluting or removing other substances. Filtration targets particulates, spraying focuses on water management, and ventilation can dilute gases but does not specifically remove hydrogen in the way recombiners do.