Important Examples

Higher cooldown, temperature lowers.

Colder temp = Denser moderator = Power rises greater than POAH

Divide total power output by every other number, you’re calculating essentially how much power per foot of fuel

*Don’t screw up units, make everything kW (1,800,000kW)

Multiply every number together except total power output (3400MW)

Then divide by total power output,

Compare Locations to result

*Don’t screw up units, make everything kW (3,400,000kW)

IRW: point to point reference

DRW and IRW relationship

(DRW POV)

DRW is SLOPE of IRW curve at pos.

DRW and IRW relationship

(IRW POV)

IRW is SUM of TOTAL Rod length

Heat Calculation Inputs

Heat Calculation

Indicated vs. Actual

Heat Calculation

Indicated vs. Actual

Calculate Core Thermal Power

Boron Worth relationship with Moderator Temperature

Differential Boron Worth becomes LESS Negative

as temperature INCREASES

At HIGHER temperatures, a 1ppm increase in Boron will add LESS boron atoms to the core

Shutdown Margin (SDM)

During Startup at the POAH (Point of adding heat)

Quadrant Power Tilt Ratio Effect on single rod drop

Ratio will RISE (worse)

LCO 3.2.4

Single Phase Coolant Flow Resistance Proportional to:

Velocity

Area

DIRECTLY proportional to velocity² (More chaos, more friction)

INDIRECTLY proportional to cross section area (More space, Less chaos, Less friction)

Delayed Neutrons

More likely to be absorbed by B-10(boron poison)

Needs fewer collisions to thermalize, less likely to fission U-238

Delayed more likely to thermalize