PROCEDURE FOR TAKING MAKE-UP IN TO THE SYSTEM

PROCEDURE FOR TAKING MAKE-UP IN TO THE SYSTEM

The tank level is to be normally maintained at approximately 220 mm . ( 255 mm HI alarm , 195 LO alarm ) .When ever the tank level drops to below 200 mm the PW system makeup to be taken up to 240 mm .

The approved committee must be informed before taking PW make up in to the system for any reason.

Always the make-up should be taken through Ion exchanger circuit only .

At a time, make-up quantity should not be more than 100 liters. However depending on the requirement thisquantity will vary.

Steps for taking Makeup :

Put DM make-up line to PW system under flushing up to the inlet valve by opening the drainvalve .

Isolate the ion Exchange circuit from the main PW system by closing both inlet and outlet valve.Ensure direct makeup is closed.

Stop alakaliser system & close the valve .

Stop Flushing of DM water after 2 hours .

Open the drain after fine filter in treatment circuit  & open the Makeup water valve  to establish flow through the ion exchanger circuit

Maintain a flushing flow rate of 1m³/hr through drain valve till conductivity after ion exchanger is 1µmho/cm .

Then get clearance from chemistry for taking makeup into system . Stop flushing by closing the drain valve .

Note down the Flow Integrator reading & SW tank level .

Take make-up by opening the ion exchanger circuit outlet valve slowly. Monitor the level in CCR as well as at local through the level gauge glass float & N2 pressure at 8.5 Mtr

If it is a normal running unit the quantity should not exceed 100 Litres at one go . If it is a shut down unit(Winding remains bypassed ) it is to be taken as per normal requirement i.e up to 300 mm in OH tank .

Precaution During Taking Makeup :-

Ensure that water does not get filled in the entire tank & enter in to purging gas line during filling oraddition of make up water.

After taking make-up, close the make-up valve. Line-up the dosing system i.e., open ion exchanger inlet valve fromPW pump discharge line. Adjust the flow in the ion exchanger circuit to 40 LPM ( 2.4 m3 /Hr )

Start Alaklyser circuit .

Nitrogen purging to be started immediately as per the following procedure from H2 filling room till O2 < 20ppb .

PROCEDURE FOR N2 PURGING AFTER SW MAKEUP

Preparatory work

After initial filling of the primary water circuit and following the addition of larger quantities of primary water (>100dm3 ( 100 Liter ) per month), the primary water tank should be purged with nitrogen to reduce the oxygen contentof the primary water.

During purging, O2 is extracted from the primary water and discharged to the atmosphere via the vent gas line.

Prerequisites for N2 purging:

The external primary water circuit was filled with water.

The primary water pumps must be available

A reliable nitrogen supply must be available.

The N2 pressure reducer was set to a gauge pressure of 0.5 bar