Week 2: Reactor Makeup System

Question 1

What is the function of the reactor makeup system?

Answer 1

To supply the RCS and various other auxiliary systems with makeup consisting of a blended boric acid solution or demineralized water.

Question 2

What systems make up the reactor makeup system?

Answer 2

Reactor makeup water system
Boric acid system
Makeup control system

Question 3

What is the function of reactor makeup water?

Answer 3

To supply water to several reactor plant systems for dilution, fill, and flushing purposes.
Specifically, the CVCS and #3 rcp seal.

Question 4

What is the water source for the reactor makeup water system?

Answer 4

The reactor makeup water storage tank.
150,000 gallons, with a rubberized diaphragm at top of tank to prevent air absorption and heaters to prevent freezing.

Question 5

Describe the function of the makeup transfer pumps.

Answer 5

To supply the system with the necessary flow of demineralized water.
Two pumps in total, each capable of 100% flow.
Controlled by FCV-111A.

Question 6

What is the function of the boric acid system?

Answer 6

To supply 4 weight percent boric acid solution to the following systems:
CVCS
RWST
SFP
HUT

Question 7

Describe the liquid source for the boric acid system.

Answer 7

There are two boric acid tanks, each with a capacity of 24,000 gallons of 7000 PPM boric acid.

Question 8

Describe the function of the boric acid transfer pumps.

Answer 8

To provide flow on demand by the makeup control system or when manually started. Controlled by FCV-110A.

Question 9

What is the function of the Boric Acid Batching Tank?

Answer 9

An 800 gallon tank used to mix the boric acid crystals with water for makeup to the boric acid tanks.

Question 10

What is the function of the Reactor Makeup Control System?

Answer 10

To deliver flow to either the VCT through FCV-111B, the CCP suction through FCV-110B, or both depending on the mode of operation.

Question 11

What are the 5 modes of operation of the Reactor Makeup System?

Answer 11

Automatic
Dilute
Alternate Dilute
Borate
Manual

Question 12

Describe the Automatic mode of Makeup System operation.

Answer 12

120 gpm blended flow
Initiated by low VCT level
Maintains the system volume at the selected boric acid concentration during normal ops.
VCT-111B closed; -111A, -110A, and -110B open.

Question 13

Describe the Dilute mode of Makeup System operation.

Answer 13

Operator Initiated
Makeup a preset quantity of pure water to the VCT in order to lower the boron concentration.
VCT-110A and -110B closed; -111B and -111A open.

Question 14

Describe the Alternate Dilution mode of Makeup System operation.

Answer 14

Operator Initiated
Allows a faster means of lowering boron concentration
Directs pure makeup water directly to the CCP suction as well as to the VCT.
VCT-110A closed; -110B, -111B, and -111A open.

Question 15

Describe the Borate mode of Makeup System operation.

Answer 15

Operator Initiated
Makeup of boric acid to the RCS to increase its boron concentration.
VCT-111A and -111B closed; -110B and -110A open.

Question 16

Describe the manual mode of Makeup System operation.

Answer 16

Operator Initiated
To allow makeup of a blended flow, pure water, or boric acid solution to any of the systems served by the reactor makeup system, including:
RWST
SFP
HUT
VCT-110B and -111B closed; -110A and -111A open.

Question 17

When is an operator required to Emergency Borate?

Answer 17

Failure of an RCCA to insert following Rx trip
RCCA height below the RILs
Reactor Makeup Control System failure
Uncontrolled RCS cooldown following Rx trip
Uncontrolled reactivity increase

Question 18

What are the Emergency Boration flowpaths?

Answer 18

Open the immediate boration valve (HV-8104) and start both boric acid transfer pumps; this path is preferred as it passes through a flow transmitter (FT-183)
Normal boration path can also be used
Alternately, FCV-110A and V-177 can be opened for another path to the charging pump suction
As a last resort, the RWST can be unisolated and routed to the CCP suction