Pennsylvania Nuclear Engineer Exam | 100 Q&A PE Nuclear Verified Rationales | PDF

PENNSYLVANIA NUCLEAR ENGINEER EXAM b b b




QUESTIONS AND CORRECT ANSWERS (VERIFIED
b b b b b




ANSWERS) PLUS RATIONALES 2026|2027 Q&A |
b b b b b b




INSTANT DOWNLOAD PDF
b b b




1. The neutron life cycle in a reactor includes all the following EXCEPT:
b b b b b b b b b b b b




 a) Fission neutron production
b b b




 b) Fast neutron slowing down
b b b b




 c) Thermal neutron absorption
b b b




 d) Moderation
b




Rationale: Fission neutron production is part of the cycle, not a separate life
b b b b b b b b b b b b


stage; the life cycle refers to neutron behavior after production.
b b b b b b b b b b




2. The effective multiplication factor keff=1keff=1 indicates:
b b b b b




 a) Subcritical reactor
b b




 b) Critical reactor
b b




 c) Supercritical reactor
b b




 d) Reactor shutdown
b b




Rationale: keff=1keff=1 means each fission leads to exactly one subsequent fission
b b b b b b b b b b


on average.
b b




3. Which material is commonly used as a moderator in light water reactors?
b b b b b b b b b b b




 a) Water
b




 b) Graphite
b




 c) Heavy water
b b




 d) Boron carbide
b b

,4. The delayed neutron fraction is important for:
b b b b b b




 a) Fuel enrichment
b b




 b) Reactor control and stability
b b b b




 c) Waste disposal
b b




 d) Heat transfer
b b




5. The primary fissile isotope used in most commercial reactors is:
b b b b b b b b b




 a) U-235
b




 b) Pu-239
b




 c) Th-232
b




 d) U-238
b




6. Fast reactors primarily rely on:
b b b b




 a) Moderation by light water
b b b b




 b) Fast neutrons without moderation
b b b b




 c) Graphite moderation
b b




 d) Heavy water moderation
b b b




7. Neutron flux is defined as:
b b b b




 a) Energy released per fission
b b b b




 b) Rate of fission reactions
b b b b




 c) Number of neutrons per unit area per unit time
b b b b b b b b b




 d) Total neutron population
b b b




8. Control rods in a nuclear reactor primarily:
b b b b b b




 a) Increase thermal conductivity
b b b




 b) Increase fuel enrichment
b b b




 c) Absorb neutrons
b b

,  d) Slow down neutrons
b b b




9. A reactor is considered supercritical if keffkeff is:
b b b b b b b




 a) <1
b




 b) >1
b




 c) =1
b




 d) ≤0
b




10. In a PWR, the primary coolant loop:
b b b b b b




 a) Directly drives turbines
b b b




 b) Transfers heat to the secondary loop
b b b b b b




 c) Is open to the atmosphere
b b b b b




 d) Contains boron only in trace amounts
b b b b b b




11–20: Thermodynamics & Heat Transfer
b b b b




11. The Rankine cycle is used in nuclear power plants for:
b b b b b b b b b




 a) Converting thermal energy to electrical energy
b b b b b b




 b) Enriching fuel
b b




 c) Reactor cooling
b b




 d) Controlling neutron flux
b b b




12. The boiling point of water increases in a pressurized reactor due to:
b b b b b b b b b b b




 a) Neutron flux
b b




 b) Elevated pressure
b b




 c) Moderator presence
b b




 d) Control rods
b b




13. The heat transfer in a fuel rod is primarily by:
b b b b b b b b b