Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NLO Systems 2023 > HP- Containment hydrogen control > Flashcards

HP- Containment hydrogen control Flashcards

1
Q

What are the functions of the HP system?

A

Monitors hydrogen concentrations in the containment building after an accident

Maintains hydrogen concentration in the containment below the lower combustible limit of 4% by volume in air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the purpose of the Containment Hydrogen Monitoring subsystem? How many redundant trains are there and what does each train consist of?

A

Measure the hydrogen concentration at two independent locations and to alert the operator in the control room of the need to activate the hydrogen recombiners or Hydrogen Purge system

two, hydrogen sensor, electronic subassembly, local and remote readout/alarms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How are the Hydrogen Analyzers started following a LOCA?

A

Manually from the control room

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where is the sample line for the Hydrogen Analyzer? Where are the Hydrogen analyzers located?

A

Taps off the suction line to the hydrogen recombiner, which is coming from containment, passes through the analyzer and returns to the containment

aux. building

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How would the Hydrogen Monitoring Subsystem be affected if HC was not in operation?

A

The air in containment would not be mixed well which would give a false reading when the analyzers are placed in service

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why is heat tracing used on the supply lines of the HP system?

A

Prevents excess condensation from developing in the lines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Concerning the Hydrogen Analyzers, what is the purpose of the Span Gas bottle?

A

Required for calibration of the unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Concerning the Hydrogen Analyzers, what is required for operation of the unit? What is required for calibration?

A

Reagent Gas Bottle

span gas bottle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Specifically, how are the analyzers started from the control room and how long before I get accurate readings?

A

Control Room operator opens the containment isolation valves and selects ‘ANALYZE’ position on the control panel

30 minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the power supply for the Hydrogen Analyzers and sample pump?

A

PH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What system supplies control power to the Hydrogen analyzers?

A

PK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the purpose of the Hydrogen Recombiner Subsystem? What is the backup subsystem in the case that both recombiners fail?

A

Provides the primary means of reducing containment hydrogen concentrations after a LOCA

HP hydrogen purge exhaust

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What hydrogen concentration are we trying to stay under?

A

4% volume, the lower combustible limit of hydrogen in air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How long do I have to connect all Hydrogen Recombiner services after a LOCA?

A

72 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How long do I have to make the Hydrogen Recombiner operable?

A

100 hours of the same LOCA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The system can be installed and functional before the hydrogen concentration reaches what percent volume?

A

3.5% volume

17
Q

To what temperature is the drawn-in atmosphere in the recombiner raised to? Basis?

A

1300F, temperature above (1150F) which free hydrogen will recombine with oxygen to form water vapor

18
Q

The Hydrogen Recombiner Standby Space Heaters receive Non-Class 120 VAC operating power from what system?

A

Lighting Power panel (QB)

19
Q

What system provides for Hydrogen mixing inside containment?

A

Containment Spray

20
Q

What happens to the Hydrogen Recombiners upon a CIAS?

A

Inlet and outlet isolation valves will close

21
Q

What is the purpose of the hydrogen purge subsystem?

A

Provides a backup installed capability for a controlled purge of the containment atmosphere in order to maintain the hydrogen concentration below 4% by volume following a LOCA

22
Q

When would the hydrogen purge subsystem be utilized?

A

In the unlikely event of the combined failure of the redundant hydrogen recombiners

It is a portable unit, so we can connect it to any of the three plant units as needed

23
Q

What is the airflow rate through the Hydrogen Purge Exhaust?

A

50 cfm

24
Q

What powers the Hydrogen Purge Exhaust Electric Duct Heater?

A

NH

25
Q

What system provides Service Air to the HP system for the positive pressure in Containment that is the driving force for air through the Hydrogen Purge Exhaust Unit?

A

Instrument Air

26
Q

Where is the Hydrogen Purge Exhaust Subsystem?

A

Unit 1 Aux Building 100’

27
Q

What components makeup the Hydrogen Purge Exhaust Subsystem?

A

Mist eliminator, heater, HEPA filters, Carbon adsorber

28
Q

Following a LOCA, what are some ways that Hydrogen is produced inside containment?

A

Metal-water reaction involving the zirconium fuel cladding and the reactor coolant

Radiolytic decomposition of the Post-LOCA emergency cooling solutions

Corrosion of metals and paints by solutions used for emergency cooling or containment spray

29
Q

What happens if Service Air is lost?

A

Hydrogen Purge subsystem is rendered Non-Functional, the Recombiners will have to be used

30
Q

How is containment atmosphere drawn into the hydrogen recombiner? What is the flow path through the recombiner assembly?

A

a gas blower

gas blower draws air in, heats it up and then flows from the heater to the reaction chamber where the conversion process occurs. reacted gas and water vapor pass through an air blast heat exchanger and then returned to containment

31
Q

Where do the hydrogen recombiners receive power from? What provides the power distribution and control instrumentation and how is it connected to the recombiner?

A

PH and PK

power and control console

connected by portable cables

32
Q

How many hydrogen recombiner skids are there and which units can use them?

A

two

all three units

33
Q

There is an adjustable timer that disables an alarm during start up; what alarm is in when the hydrogen recombiner is starting up?

A

low gas temp

34
Q

What is the flow path of the HP hydrogen purge subsystem? What is the purpose of the unit heater?

A

pressurized air flows into the hydrogen purge unit, and through a mist eliminator and unit heater. after the heater, air passes through a HEPA filter, a carbon filter, and another HEPA filter and goes to the plant vent

keep humidity below 70%

35
Q

In order to align the HP hydrogen purge subsystem to containment, what is the maximum temperature and pressure?

A

180*F and 10 psig

or when hydrogen concentration reaches 3.5% volume

36
Q

What is the auto feature that will isolate the HP hydrogen purge exhaust subsystem?

A

CIAS

recombiner inlet and outlet also serve the hydrogen purge exhaust system

37
Q

Concerning the hydrogen recombiners, what is the purpose of the trickle heater and how long must it be on prior to using the recombiner?

A

takes 24 hours to get up to 1300*F that’s required for operation

NLO Systems 2023 (67 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions