CH-Reactor Coolant Pump Seal Injection, Controlled Bleedoff, and Chemical Addition subsystems

Question 1

What is the purpose of the RCP seal injection?

Answer 1

CVCS provides injection water to RCP seals. the flow cools the seal cavity and provides filterd/deionized flushing which minimizes radioactive crud in the seal cavity.

Question 2

What is the purpose of RCP controlled bleedoff?

Answer 2

CVCS receives controlled bleedoff from RCP pump seals normal path to VCT. Face seal leaks are collected in the RDT. If containment is isolated controlled bleedoff can be vented to RDT via a safety relief valve in the bleedoff header.

Question 3

What is the purpose of Chemical addition subsystems?

Answer 3

CVCS maintains Reactor coolant chemistry for the control of corrosion.
Oxygen is controlled by adding Hydrogen during start up. CVCS controls pH with boric acid and lithium hydroxide.

Question 4

What is the RCP seal injection flow path?

Answer 4

From upstream of RHX flow passes thru SIHX to seal injection filters then splits 4 ways to the RCPs.

Question 5

Where does RCP controlled bleedoff flow?

Answer 5

VCT if the containment isolation valves are closed it flows to the RDT

Question 6

How are chemicals added to the RCS?

Answer 6

Via the CVCS chemical addition pump. It takes suction from a chemical addition tank/hydrazine addition pot and discharges to the charging header upstream of RHX.

Question 7

What is the purpose of the seal injection filters?

Answer 7

They are downstream of the SIHX and remove insoluble particles to prevent RCP seal damage.

Question 8

What is the design of the seal injection filters?

Answer 8

They are replaceable cartridges and remove particles larger than 2 microns. Made of stainless steelfor corrosion prevention. 1 in service 1 in standby.

Question 9

What is the purpose of the CVCS chemical addition tank?

Answer 9

Allows chemical addition to the RCS. Lithium is added to raise the low pH induced by boric acid addition.
Hydrazine is added for oxygen control when RC <250*.
Hydrogen Peroxide is add to initiate a CRUD burst.

Question 10

What is the design of the CVCS chemical addition tank?

Answer 10

8 gal tank of stainless steel. CHEMISTY department dissolves chemicals and AO’s control Rx makeup water for diluting chemicals. A filter downstream prevents large particulates. The strainer can be flushed.

Question 11

What is the purpose of the CVCS chemical addition pump?

Answer 11

Adds chemicals to the RCS

Question 12

What is the design of the CVCS chemical addition pump?

Answer 12

Between RHX and CHA-HV-524. Variable PDP max capacity 25 gph at 2735 psig powered by NH.

Question 13

What is Lithium Hydroxide for in the CVCS chemical addition subsystem?

Answer 13

At the beginning of life used to control corrosion and pH in the RCS.
Once lithium concentration builds up enough we nightly delithiate to control pH.

Question 14

What is hydrazine for in the CVCS chemical addition subsystem?

Answer 14

During shutdown RCS is made acidic and oxidized to control CRUD and corrosion. Scavenges oxygen, but doesn’t work in hi temps good <235*.

Question 15

What is hydrogen peroxide for in the CVCS chemical addition subsystem?

Answer 15

Initiates a CRUD burst at the beginning of outage.

Question 16

What is the purpose of the portable Hydrazine Addition Pot?

Answer 16

It allows for safe addition of hydrazine w/o the potential exposure.

Question 17

What is the design of the portable hydrazine addition pot?

Answer 17

A 12.5 gal stainless steel tank, lid has hold-down wingnuts. Chemistry keeps and bring to to Demin Op to fill then to aux bldg to add to chemical addition pump room.