Combustible gas

Question 1

Do hydrogen igniters auto start?

Answer 1

no

Question 2

What are hydrogen ignitors made of?

Answer 2

they are a glow plug

Question 3

Do the hydrogen recombiners auto start?

Answer 3

no

Question 4

When should the hydrogen recombiners be started?

Answer 4

> 1% hydrogen

Question 5

When should they be secured? why?

Answer 5

Prior to 6% before they become overloaded and could damage the unit

Question 6

How many hydrogen analyzers are there?

Answer 6

4 (2 in ctmt and 2 in DW)

Question 7

Where are the hydrogen analyzers?

Answer 7

2 in ctmt and 2 in the DW

Question 8

Do the hydrogen analyzers auto start?

Answer 8

YES! on a LOCA

Question 9

When do the hydrogen analyzers start?

Answer 9

on a LOCA

Question 10

If CTMT pressure is lower than drywell pressure, what position are ALL vacuum breakers in?

Answer 10

closed??

Question 11

When will CTMT purge isolation valves F009/F010 close?

Answer 11

LOCA signal
NSSSS LOCA
CTMT/DW exhaust HI-HI Rad 3.6 mr/hr
Manual isolation pushbutton

Question 12

When will filter train exhaust isolation valve F036/F037 close?

Answer 12

NSSSS LOCA Initiation

SBGT initiation HI-HI Rad or manual

Question 13

Which systems are safety related and which are not?

Answer 13

Safety - Post LOCA vacuum relief, Hydrogen control, Drywell purge

Non Safety - CTMT purge, Normal drywell vacuum relief

Question 14

After a LOCA signal, with signal still present, when can CTMT isolation valves be re-opened?

Answer 14

24 hours after receiving the signal

Question 15

What will happen if DC power is lost while drywell purge compressor is running?

Answer 15

nothing dude

Question 16

What percent do the hydrogen recombiners maintain hydrogen levels in CTMT/DW?

Answer 16

< 4%

Question 17

What are the flammable and explosive ranges of hydrogen

Answer 17

< 4% Non combustible

4 - 18% Combustible/flammable

18 - 59% Explosive/detonable

59% - 75% Combustible/flammable

> 75% Non-combustible

Question 18

What is the primary use of CTMT purge subsystem

Answer 18

backup to hydrogen recombiners

Question 19

What’s the purpose of combustible gas?

Answer 19

1. Control the concentration of hydrogen that may be released into CTMT/DW following a LOCA
2. Prevents a vacuum from being drawn into the drywell
3. Relieve a vacuum that could occur due to failure of normal ventilation and air conditioning

Question 20

What are the auto starts of the drywell purge compressors?

Answer 20

LOCA
and
30 seconds
and 
Drywell > .87 psig above CTMT pressure

Question 21

What are the trips to the drywell purge compressors?

Answer 21

Low oil pressure < 15 psig bypassed unless in test

High oil temp > 155 deg F bypassed unless in test

MPD

ESF load shed

Local breaker pushbutton

Question 22

When will post LOCA vacuum relief valves open?

Answer 22

LOCA

and

30 seconds

and

Drywell .88 psig below CTMT pressure

and

Drywell < .87 psig above CTMT pressure or CGCS manual initiation

Question 23

What’s the logic for normal vacuum relief operation?

Answer 23

HS permissive met (auto and back to auto)

> 60 psig instrument air (F020 only)

NO LOCA

DW < .186 below CTMT (contact is reclosed < 1.6 below CTMT

when all of the contacts are closed, valve is open (F007 and F020)