AM

Question 1

What are the Acceptance criteria for ECCS per 10CFR 50.46(Bases for LCO 3.5.2. ECCS operating)?

Answer 1

• The calculated maximum fuel element cladding temperature shall not exceed 2200F.
• The calculated total oxidation of the cladding shall nowhere exceed .17 times the total cladding thickness before oxidation.
• The calculated total amount of H2 generated shall not exceed .01 times the amount that would be generated if all the cladding were to react.
• Calculated changes in core geometry shall be such that the core remains amenable to cooling.
• The calculated core temperature shall be maintained at an acceptable low value and decay heat shall be removed for the extended period of time required by the long-lived radioactivity remaining in the core.

CLOTH

Question 2

At what temperature are SAMG (Severe Accident Management Guidance) enter?

Answer 2

Core exit T/Cs are greater than 1200°F and actions to cool the core are unsuccessful

Question 3

At what temperature does the Zirc-Water reaction become self-sustaining?

Answer 3

2300 degrees F

Question 4

What are four basic requirements for maintaining natural circulation?

Answer 4

• There must be a heat source.
• There must be a heat sink.
• The heat sink must be higher than the heat source.
• There must be a complete flow path for circulation of the fluid to and from the heat sink and the heat source.

Question 5

What are indications of natural circulation?

Answer 5

• Core thermocouples decreasing or holding steady
• Loops wide range Th decreasing or holding steady
• Relatively large loop Delta T (Th-Tc), less than or equal to full power Delta T using wide range indications
• S/G pressure constant or decreasing at same rate as Th is decreasing
• S/G levels constant with constant feed flow

Question 6

Which Nuclear Instrumentation is qualified for containment adverse conditions with indication from the source range through the power range?

Answer 6

The Wide Range fission chamber indication (ENC)

Question 7

If an RTD gets a short circuit, its indication will do what?

Answer 7

fail low

Question 8

If an RTD gets an open circuit, its indication will do what?

Answer 8

read high

Question 9

At what temperature does the Zirc-Water reaction start?

Answer 9

1800 degrees F

Question 10

What are the 5 methods of core cooling?

Answer 10

• Forced Circulation
• Single Phase Natural Circulation
• Two Phase Natural Circulation
• Reflux Cooling
• Feed and Bleed

Question 11

What is Reflux cooling?

Answer 11

Steam goes to the hot leg side of the S/Gs and is condensed and then flows back to the core through the hot leg piping.

Question 12

What is Single Phase Natural Circulation?

Answer 12

Flow through the core due to a change in density with liquid throughout the NCS.