Head Spray

Question 1

What are the Reactor Head Cooling System Operating Limits?

Answer 1

Flow shall not exceed 170gpm
CRD Pp Motor shall not exceen 39 amps
CRD Pp Operation with <100gpm should be minimized to prevent axial shuttling
When using single pump for head spray and CRD flow, cooling flow
and min flow may be reduced to maintain flow (>100; <200gpm)

Question 2

What simultaneous operations should be minimized when on head cooling?

Answer 2

CR movement should be minimized.

Head cooling flow should be reduced when charging water low pressure alarm is reached

Question 3

What are the RCS heatup and cooldown rates per TS 3.4.9?

Answer 3

RCS Heatup and cooldown rates are <100F in any 1 hour;
RCS Temp Change <20F in 1 hr during inservice leak/hydro testing
Rx Vessel Flange and Head flange temp >83F

Question 4

What are teh differential temp limits per TS 3.4.9?

Answer 4

Difference betwen bottom head cooland and RPV coolant <145F

Question 5

When is Reactor Head Spray used?

Answer 5

Shutdown conditions to collapse steam bubbles in Head during floodup
Also commonly used during Hydro pressurizing