Which statement reflects a safety implication of PWR design compared with BWR?

Which statement reflects a safety implication of PWR design compared with BWR?

• A. PWR’s separated primary and secondary loops aid containment isolation and secondary-side decoupling.
• B. BWR uses no containment features.
• C. PWR uses steam directly in reactor vessel.
• D. BWR uses a closed primary loop.

Answer: (B)

Separated primary and secondary loops in a PWR create a clear boundary between the radioactive reactor coolant and the turbine steam cycle. Heat is transferred to the secondary loop through steam generators, so the primary loop stays contained and isolated from the steam system. That separation makes containment isolation easier and reduces the chance that a problem on the secondary side could propagate into the reactor coolant system, which is a key safety advantage. In a BWR, steam is produced directly in the reactor vessel, so the primary coolant and the steam going to the turbine are more directly linked. This means the pathways for coupling between the reactor coolant and the turbine loop aren’t as distinctly separated as in a PWR, which is the safety implication the PWR design highlights. Containment features exist in both designs, so the claim that a BWR has no containment features isn’t accurate. Also, saying a PWR uses steam directly in the reactor vessel is incorrect—this describes a BWR. Finally, while a BWR does have a closed primary loop, that isn’t the distinguishing safety implication compared with a PWR.

Separated primary and secondary loops in a PWR create a clear boundary between the radioactive reactor coolant and the turbine steam cycle. Heat is transferred to the secondary loop through steam generators, so the primary loop stays contained and isolated from the steam system. That separation makes containment isolation easier and reduces the chance that a problem on the secondary side could propagate into the reactor coolant system, which is a key safety advantage.

In a BWR, steam is produced directly in the reactor vessel, so the primary coolant and the steam going to the turbine are more directly linked. This means the pathways for coupling between the reactor coolant and the turbine loop aren’t as distinctly separated as in a PWR, which is the safety implication the PWR design highlights.

Containment features exist in both designs, so the claim that a BWR has no containment features isn’t accurate. Also, saying a PWR uses steam directly in the reactor vessel is incorrect—this describes a BWR. Finally, while a BWR does have a closed primary loop, that isn’t the distinguishing safety implication compared with a PWR.