L-4

Question 1

Describe the fuel conditioning limits less than 50% power?

When fuel conditioning limits are relaxed, are there any other limits that apply? If so what are they? Why?

Describe the fuel conditioning limits concerning the control rods?

Answer 1

< or = 50%, no fuel conditioning limits exist

yes, an admin limit of 5 MW/ min, minimize effects of Xenon oscillations on delta I

• 3 steps / hr when:
  
  • withdrawing above previously reached position in s/u. OR
  • power above conditioned power level

(minimize local power increases)

Question 2

When a reactor is achieving initial criticality and power ascension to 100% power what if any limitations are there on power increase > 50% power?

Describe

Answer 2

yes, 3% / hr until fuel is conditioned

conditioning requires:

• being maintained at given power for 72 hrs in 7 day period
• once conditioned no limits apply
• fuel keeps conditioning for 27 days

(significantly reduces probability of fission product release from fuel to coolant if flaw exists)

Question 3

What T.S. Must be met prior to exceeding 50% power?

Answer 3

QPTR

AFD

Question 4

What adverse problems exist with long life cores?

Answer 4

Axial flux anomilies

rods failing to insert (bowed guide tubes)

clad corrosion

Question 5

When ramping from 2-30% power what three indicators should be cross referenced to ensure reasonable agreement?

When swaping from sequential to single valve mode, what feedbacks should be in?

Answer 5

• PR NI’s
• IR NI’s
• loop delta T’s
• MW feedback
• IMP feedback