L-5

Question 1

What RCP pump operation should be limited when Tavg < 350 deg F?

Why?

Answer 1

U-1 RCP 1-1, 1-3

U-2 RCP 2-2, 2-4

shaft cracking due to rotation of RCP

Question 2

How many RCP’s are required to be in operation in Mode 3?

why?

Answer 2

2 when rod control is capable of withdrawing rods

1 if rod control is not capable of withdrawing rods

possible inadvertant rod withdrawal accident and power excursion => 2 pumps ensures accident analysis met

Question 3

When inserting control rods for shutdown in OP L-5, what must be done with control rods?

Why?

Answer 3

Once they are inserted they must be inserted continuously.

this prevents any reactivity control problems due to cooldown

Question 4

Once the cooldown and de-pressurization commence how must P_rcs be controlled versus P_s/g ?

Answer 4

They must be lowered together

and

P-11 (1915 psig) must be reached AND BLOCKED before P_s/g reaches 600 psig

=> no inadvertant SI

Question 5

During RCS c/d and depress what limits must be adhered to?

Answer 5

cooldown limits

• RCS 100 deg/ hr
• Pzr 200 deg/ hr

Press limits

• > 1600 psid accross u-tubes
• inside cooldown curve

Heatup limits

• RCS 60 deg/ hr
• Pzr 100 deg/ hr