NANTeL Chemistry and Water Treatment 2

Question 1

What is the primary function of a demineralizer (ion exchange unit) in nuclear plant water treatment?

Accepted Answer

To remove dissolved minerals and ionic impurities from water

Answer

Demineralizers use cation and anion exchange resins to remove dissolved ionic impurities, producing the high-purity water required for reactor coolant makeup and other critical systems.

Question 2

Which water quality parameter is most commonly used to assess the ionic purity of nuclear plant makeup water?

Accepted Answer

Specific conductivity (µS/cm)

Answer

Specific conductivity directly measures dissolved ionic content; nuclear makeup water targets are typically a fraction of a microsiemen per centimeter, making it the primary purity indicator.

Question 3

What are the primary functions of the Chemical and Volume Control System (CVCS) in a pressurized water reactor?

Accepted Answer

To maintain RCS inventory, control boron concentration, and purify reactor coolant

Answer

The CVCS maintains RCS water inventory, adjusts boric acid concentration for reactivity management, and continuously purifies coolant via letdown filters and mixed-bed demineralizers.

Question 4

Why are resin traps or fine-mesh strainers installed downstream of ion exchange vessels in nuclear plant systems?

Accepted Answer

To capture resin beads that break free and prevent downstream contamination

Answer

Resin traps prevent loose or broken resin beads from traveling downstream into pumps, valves, and the reactor coolant system, where they could cause mechanical damage or chemistry upsets.

Question 5

In nuclear plant secondary chemistry, what is the operational purpose of steam generator 'blowdown'?

Accepted Answer

Removal of concentrated water to control dissolved-solid buildup in steam generators

Answer

Blowdown removes a continuous or intermittent stream of concentrated secondary water from the steam generator to prevent scaling, corrosion, and tube fouling caused by accumulation of dissolved solids.

(NANTeL) National Academy for Nuclear Training e-Learning Practice Test

(NANTeL) National Academy for Nuclear Training e-Learning Practice Test

NANTeL Chemistry and Water Treatment 2