24/48vdc System

Question 1

What is the purpose of the 24/48 vdc system?

Answer 1

Provide power to NI, PRM, SIV instrument under all plant conditions

Question 2

Where are the 24/48 vdc batteris?

Answer 2

Unit Battery rooms

Question 3

Where is the 24/48 battery charger fed from?

Answer 3

AC input from Instrument Bus

Question 4

What is unique about the 24/48vdc system?

Answer 4

It is the only grounded battery system.

Question 5

For the 24/48vdc system how many knife switches are and how what do they connect in?

Answer 5

3 - Undervoltage, Overvoltage, voltmeter

Question 6

How is the 24/48vdc system configured?

Answer 6

It is a 2 pole system, positive and negative battery system

Question 7

What is the undevoltage set for 24/48?

Answer 7

22.8V

Question 8

How many UV, OV, and Voltmeters are there for the 24/48 system?

Answer 8

2 of each. One per pole

Question 9

How many distribution panels are there associated with the 24/48 system?

Answer 9

2 per unit (2A and 2B)

Question 10

What happens on a loss of 2A dist. panel (24/48)?

Answer 10

Loss of SRM channel 21&22, IRM channels 11 through 14 (mult. alarms.
Breakers that power SRMs and IRMs power Div II SIV level switches - therefore, half scram on RPS A
Sping goes downscale initially

Question 11

What happens on loss of 24/48 2B DP

Answer 11

Loss of SRM 23 & 24, IRM 15 thru 18; multiple alarms
Div I SIV Rosemont level switch - causes RPS B half scram
Loss of Power to RBCCW and Service Water Rad Monitors

Question 12

What happens on loss of 24/48 VDC 3A DP?

Answer 12

Loss of SRM 21 & 22, IRM 11-14; multiple alarms

Reserve feed for 2/3 chimney monitor

Question 13

What happens on loss of 3B 24/48 DP?

Answer 13

Loss of SRM 23 & 24, IRM 15 thru 18, multiple alarms

Loss of power to RBCCW and Service Water Rad Monitors

Question 14

Which Units Receive half scram signal on loss of 24/48?

Answer 14

Unit 2 Only - Loss of 2aDP - Div II SIV level switch power lost
loss of 2B DP - Div I SIV level switch power lost