Reactor Vessel & Internals - .5

Question 1

Reactor is rated for…

Answer 1

• 3902 MW
• 100x10^6 lbm/hr
• 1250#

Question 2

What is the T/S max pressure of the vessel?

Answer 2

1325 psig in vessel head head (accounts for 50# rise, 1375 in pressure vessel).

Question 3

What is the maximum HUR/CDR?

Answer 3

100F/hr, 90F ADMIN

Question 4

Baffle Plate

Answer 4

Supports shroud and jet pumps.

Question 5

Core Plate

Answer 5

• Partition for core flow.
• Provides vertical and lateral support for 24 peripheral bundles.
• Provides lateral support for the Four-lobed Fuel Supports/Fuel Bundles
  and Control Rod Guide Tubes

Question 6

Top Guide

Answer 6

Provides lateral support for all fuel bundles, in core monitoring devices, and sources.

Question 7

CRD Housing

Answer 7

Provides vertical and lateral support for CRDs. Transfers weight to the bottom head.

Question 8

CRD Guide Tubes

Answer 8

Align CRDs and supports center fuel bundles.

Question 9

Fuel Support Piece

Answer 9

Provides vertical support for fuel assemblies (contains orifice).

Question 10

CRD Support Housing

Answer 10

Prevents ejection of control rod(s) in the event of a failure of CRD drive housing (<3” or 1 notch in travel).

Question 11

Moisture Separator

Answer 11

14% to 90% quality. (Core Avg. exit quality is ~14%)

Question 12

How does the Steam Dryer affect steam quality?

Answer 12

90% to 99.9% quality.

Question 13

Describe O.E. Regarding Core Shroud

Answer 13

Core shrouds have cracked leading to a power drop due to steam bypassing moisture separator and heating the feedwater in the annulus area.

Question 14

When should MSIVs be procedurally closed?

Answer 14

Prior to reaching +90’

Question 15

Indications of core shroud cracking (ABOVE TOP GUIDE)

Answer 15

• APRM power goes down quickly due to bypass flow heating water in the outer shroud.
• IND core flow may go up due to no pressure drop across dryers.
• Recirc suction temp goes up
• Rod line decreases.

Question 16

Indications of core shroud cracking (BETWEEN TOP GUIDE & CORE PLATE)

Answer 16

• APRM Power goes down as voids form in bypass region.
• Recirc temps do not rise because water leaking is subcooled.

Question 17

Indications of core shroud cracking (BELOW CORE PLATE)

Answer 17

• Core d/p goes down
• Power goes down because flow into core is less
• Flow may read the same.

Question 18

What are the flows through core?

Answer 18

Recirc flow - 1/3 drive
Feed water - 2/3 driven

Question 19

Carryover results in:

Answer 19

• Increase in Turbine wear
• Increase in RADs in BOP
• Decrease in turbine efficiency

Question 20

Carryunder results in:

Answer 20

• Decrease in plant efficiency
• Decrease in core inlet subcooling
• Increase chance of recirc/jet pump cavitation

Question 21

FW penetration level:

Answer 21

-29”

Question 22

Core Spray penetration level:

Answer 22

-43”

Question 23

RHR penetration level:

Answer 23

-155”

Question 24

Recirc inlet penetration level:

Answer 24

-346”

Question 25

Recirc outlet penetration level:

Answer 25

-366”

Question 26

What supports the shroud vertically in the core?

Answer 26

shroud support plate