N32 - EHC

Question 1

What is the EHC system mainly controlling?

Answer 1

Reactor pressure to control reactivity

Question 2

What happens if turbine limit (setpoint) is exceeded?

Answer 2

Bypass valves open

Question 3

What happens if EHC pump ‘B’ < 1600 psig @ >26% power?

Answer 3

Turbine trip and reactor SCRAM

Question 4

how many overspeed protection systems are required?

Answer 4

Both of them:

DOPS and back-up overspeed (ovation)

Question 5

How many bypass valves are there?

Answer 5

3 bypass valve.

Question 6

How much can bypass valves bypass?

Answer 6

30%, (10% each valve)

Question 7

How many bypass valves are required? why?

Answer 7

2 required

thermal limit penalty imposed by MCPR and LHGR

Question 8

How many stop and control valves are required?

Answer 8

ALL of them

Question 9

If EHC is ingested, what should be done?

Answer 9

induce vomiting

Question 10

What PPE should be used when around EHC fluid?

Answer 10

Glove, face shield, respirator

Question 11

What type of respirator should be used when handling EHC fluid?

Answer 11

Air purifying

Question 12

What level should not be exceeded when filling EHC reservoir? why?

Answer 12

34” to prevent overfilling tank

Question 13

when will the standby EHC pump auto-start?

Answer 13

<1800 psig on running pump OR header if pump is in Auto-STBY

Question 14

What are the EHC pump trips?

Answer 14

< 15” EHC tank level LO-LO

MPD

Question 15

What are the heater start permissives?

Answer 15

> 15” tank level

Recirc pump must be running

< 105 deg F heater start

> 115 deg F heater stop

Question 16

When will the main turbine trip relative to EHC pressure

Answer 16

<1600 psig

Question 17

What does the cornsilk color mean?

Answer 17

it is selected

Question 18

When does the high filter DP alarm come in?

Answer 18

> 72 psid

Question 19

What’s the primary purpose of the stop valves?

Answer 19

prevent overspeed of turbine on turbine trip

Question 20

on a turbine trip, what controls Rx pressure?

Answer 20

Bypass valves

Question 21

What must be done for a setpoint to be active?

Answer 21

Enable or confirm it

Question 22

How do control/bypass/stop valves operate?

Answer 22

Fluid to open, spring to close

Question 23

what valves are fast close, and which are fast opening?

Answer 23

Fast close – stop and control valves

Fast opening – bypass valves

Question 24

What’s the power supply to EHC pumps?

Answer 24

A - 13AD

B - 14AE

Question 25

What’s the power supply to Ovation?

and control power?

Answer 25

Inverter power 120 VAC (BOP)

Question 26

What’s the tech spec part of EHC? (safety function)

Answer 26

BYPASS VALVES

Question 27

What cools EHC

Answer 27

TBCW

Question 28

How does the Temp control valve fail?

Answer 28

OPEN (max cooling)

Question 29

What needs to be running to run the EHC heater?

Answer 29

Recirc pumps

Question 30

What temp does the heater maintain?

Answer 30

105 - 115 deg F

Question 31

What the SCRAM setpoints? (EOC RPT) and (EHC pressure)

Answer 31

TSV < 675 psig

TCV < 970 psig

<1600 psig header pressure

Question 32

When are the SCRAM setpoints bypassed?

Answer 32

< 26% Rx power

Question 33

What type of SCRAM is the EHC scram?

Answer 33

RPS scram

Question 34

What is temp maintained at when running by temp control valve?

Answer 34

115 - 130 deg F