KANUPP – IAEA Training
Boiler Feedwater / Condensate Chemistry Control
Slide 1
Boiler Feedwater / Condensate Course Objectives
• • State the purpose of secondary side chemistry control. State what chemicals are added to the secondary side, the purpose of each chemical, and where each chemical is added. State the chemical parameters monitored in the secondary side by plant instrumentation, their sampling points, approximate values and what alarms/indications are available in the MCR. Appreciate the need for good communication between the CRO and Chemical Maintainer with respect to alarms received in the MCR, i.e., out of spec parameters, low tank levels, power changes, bypassing of flow through the condensate polishers, etc.
•
•
Slide 2
Course Objectives
• State the consequences of out of spec parameters on Secondary Side plant systems and components. Recognize condenser sea water leak indications; state the concerns and general procedure to follow in the event of a condenser sea water leak State what indications are in place to give indication of a Steam Generator Tube leak. State the main concerns associated with a Steam Generator Tube leak.
•
•
•
Slide 3
CONDENSATE FEEDWATER – BOILER SYSTEM
Make-up Water
Secondary Heat Transport System
The Essay on Еhe chemical weapons
Regarding the issue, the article that supports the chemical weapons presented that (1) some countries particularly US developed a program that aims for uncomplicated and more accessible ways to identify biological agents, and (2) chemical weapons can be used by nations in preparation for their defense against terrorism. On the other hand, chemical weapons are opposed by the antagonist by citing ...
FeedWater Condensate Boilers Steam Systems
Slide 4
Condensate – Feedwater – Boiler System Chemistry Control
Chemistry Objectives
• Minimize Corrosion in order to preserve system integrity and ensure the long term availability of equipment. Minimize Local Corrosion of Boiler materials which can occur in regions of restricted flow, particularly under deposits and within crevices. Minimize transport of corrosion products into the Boilers (condensate – feedwater corrosion).
Minimize erosion in steam – turbine – feedwater – condensate.
•
•
•
Slide 5
Condensate – Feedwater – Boiler System Chemistry Control
Corrosion Concerns
•
Can produce alkaline conditions under deposits or in crevices which can result in stress corrosion cracking of boiler tubes. (All Volatile Chemistry Treatment) Can produce acidic conditions under deposits or in crevices which can result in stress corrosion cracking of boiler tubes. High levels in combination with oxygen can cause pitting of boiler tubes and carbon steel components. Can also result in generalized corrosion of carbon steel support plates which can cause boiler tube “Denting”. Corrosion of materials in the Condensate/Feedwater system Corrosion products are transported to the boilers where they accumulate on the tubesheet and tube support plates – increased boiler deposits. Increased deposits can also result in decreases in heat transfer at the boiler tube surfaces which in severe cases can result in power derating.
Sodium:
• •
Sulfate:
Chloride:
•
Products:
•
Slide 6
Calcium & Magnesium : Increased boiler deposits. Silica: Increased boiler deposits.
•
Specific Conductivity – conductivity of the solution contributed by all the dissolved ionic species. e.g. cations (Na+, Li+, Cu++, Ca++, Mg++, NH4+, N2H4+, C4H9ON+ , etc) anions (Cl-, F-, NO3-, SO4–,PO4— etc) Cation Conductivity – conductivity of solution contributed by dissolved ionic impurities/contaminants. e.g. cations (Na+, Cu++, Ca++, Mg++) are exchanged with H+. The anions that remain (Cl-, F-, NO3-, SO4–, PO4— ) now are in the for of mineral acids and are highly conductive giving a rise in the conductivity of the solution (Sample stream of feedwater passed through a cation resin in the R-H+ form)
The Essay on Biomass Steam Boiler Water-Steam System
Biomass steam boiler water-steam system In the process of biomass steam boiler use,we should pay special attention to its water-steam system to ensure the stable steam generating.Biomass steam boiler water-steam system is to absorb the heat fuel released,make the water eventually become the steam of specified pressure and temperature,it consists of drum,water wall,superheater,reheater, down ...
Slide 7
Cation Conductivity Measurement
Color indicating resin brown- exhausted Duplicate Resin Cartridges purple – fresh
Measuring element
Slide 8
Condensate – Feedwater – Boiler System Chemistry Control
Condensate Chemistry Control
• Maintain Dissolved Oxygen Levels Low: Location and elimination
of sources of air in-leakage in the sub-atmospheric portions of the turbine/condenser system. Hydrazine addition.
•
Maintain Alkaline pH Conditions: Addition of Morpholine. Plants
with copper alloys in the condensate system operate at slightly lower than optimum pH conditions (for carbon steel).
High amine concentrations can result in stress corrosion cracking and condensate grooving of copper containing components. Hydrazine concentrations also limited to the minimum necessary for oxygen scavenging due to ammonia formation due to hydrazine decomposition. Since Point Lepreau system does not have copper components, high morpholine & hydrazine concentrations can be tolerated …… morpholine is maintained at @ 15 mg/Kg & hydrazine is maintained between 60 – 80 ug/Kg.
Slide 9
Slide 10
OM 78210, Appendix 1. Actions upon Detection Of a Condenser leak
Sodium or Cation Conductivity in alarm on one or more Condensers. AND Sodium or Cation Conductivity in alarm on the CEP Discharge
CRITERIA 1.
Condenser
CD01 CD02 CD03
Condenser Indications
(Any Of)
WII-6 CI 1873 NA+ AI 2764 Cat Con Al 2766
Wll-6 CI 1873 AI 0551 Al 0564 AND
WII-6 CI 1873 AI 2765 Al 2767
CEP (Either of)
Cat Con AI 1014 Na+ AI 1015
OR
CRITERIA 2.
Any single alarm and trending that indicates we are approaching a CRITERIA 1 situation as monitored by the Chemistry Department
Slide 11
Condenser Leak Cation Conductivity and Sodium Local Meters
Slide 12
Condenser Leak Detection CD01 -16’ elev. T/B
The Essay on Water 5
Thesis Statement: Water is the most crucial part of life its self, and must never go unnoticed. I. People frequently overlook the importance of water in the body. In order to keep the body healthy, people must consume water. A healthy body is a well-hydrated body. Without the constant consumption of water the body becomes dehydrated. Perhaps people overlook waters importance, simply because its ...
Slide 13
V337
V338
Slide 14
(May give indication of a Condenser Tube leak) 1. turbine trip 2. reactor trip 3. ∆ R.P. 25% 4. warm-up 5. 6. 7. 8. cool-down poison prevent plant start-up placing condensers in service
Transient Conditions
Condenser Sea Water Leak Flow Chart
(Reference: OM 45100-1 Appendix 2)
No Polisher in Service
Conditions stabilized? Yes sodium > 100 ppb(AT13) and 1 or more of: Cat Cond > 0.10 mS/m (CT6) sodium >300 ppb (AT 20, 22, 23) Cat Cond > 0.30 mS/m (CT 19, 24, 25)
Perform normal monitoring
No
Yes No Trending up? Yes
Investigate further
No reduction in R.P. necessary On start-up do not raise R.P. above 10% unless Cl- are trending down. If R.P. >10%, hold or reduce to 60% until Cl- are trending down.
Yes
Boiler Chloride
A
Chart 2
Yes Boiler Chloride 1.0 to 2.0 ppm No
On start-up do not raise R.P. above 2%. If R.P. >2%, hold or reduce to 60%. If downward trend is not evident within 30 minutes, shutdown. (see note 1)
Yes Boiler Chloride
Slide 15
Condenser Sea Water Leak Flow Chart Steady State Conditions
(Reference: OM 45100-1 Appendix 2)
A
IF:
No 1. sodium > 1.0 ppm on 2 successive samples (taken within 30 minutes).
or 2. Boiler Cl- > 10 ppm on 2 successive samples (taken within 30 minutes) & leak not isolated. or 3. Boiler Cl- > 20 ppm on 2 successive samples. or 4. Boiler Cl- > 1 ppm for a 24 hr. period, (see note 1).
or 5. See note 2. Yes
No Polisher in Service
Immediately reduce R.P. to 60% full power
The reactor must be shutdown in an orderly manner and the PHT cooled@ the max. permissible rate (2.8oC/min) to 100oC.
NOTE 1: Shutdown can be waived or postponed by Station Management NOTE 2: If the boiler pH is 1.0 mS/m @ polisher discharge on 2 successive samples taken within 30 min. or Boiler Cl- > 10.0 ppm on 2 successive samples & the leak has not been isolated. or Boiler Cl- > 20.0 ppm on 2 successive samples. or Boiler Cl- > 1.0 ppm for a 24 hour period. (See note 1) or See note 2.
The reactor must be shutdown in an orderly manner and the PHT cooled @ the max. permissible rate (2.8o C/min) to 100o C.
The Term Paper on Hardness Of Water Edta Ppm Tap
Water is the most important molecule that exists on the Earth. Without water living beings would not be able to live. Water is used for an immeasurable number of things. There are many properties of water, which makes this molecule so unique. One which people overlook is hardness. Hardness is defined in the Chemistry: The Central Science by Prentice Hall's as being "water that contains a ...
Note 1: Shutdown can be waived or postponed by Station Management. Note 2: If the boiler pH is 10.5 after 1 hour and the pH is not returning to normal, derating and/or shutdown may be rerquired after consulting with the Station Chemist. If boiler pH 11.0 and the Station chemist can not be contacted, shutdown.
Slide 17
BASIC PHILOSOPHY OF SECONDARY WATER CHEMISTRY CONTROL
1. Tight Condenser Prevention of Impurity Ingress 2. Make up Water Treatment 3. Control of Water Treatment Chemicals
1. Condensate Polishers Removal of Impurity 2. Boiler Blowdown 3. Deaeration
Prevention of Corrosion
Optimize Conditions
1. pH Control 2. Hydrazine Addition
Slide 18
Condensate – Feedwater – Boiler System Chemistry Control
Feedwater Chemistry Control
• • Maintain Dissolved Oxygen Levels Low: Accomplished by
Dearation and by Hydrazine addition.
Maintain Alkaline pH Conditions: High pH conditions minimizes
carbon steel corrosion. Accomplished by Morpholine addition. Morpholine concentration maintained by operating the Condensate Polishers in the Morpholine form.
Slide 19
Slide 20
Condensate – Feedwater – Boiler System Chemistry Control
Steam System Chemistry Control
• Maintaining alkaline pH conditions in the water systems: Accomplished with the addition of morpholine. Reduction in Erosion/Corrosion in Two-Phase wet steam regions is particularly important. The key is to maintain pH in the
liquid phase high enough to minimize carbon steel corrosion. This is more easily achieved with Morpholine, which tends to remain in the liquid phase due to its more favourable distribution ratio, as compared to ammonia which favors the steam phase.
•
Slide 21
Steam Generator Tube Failures
• During normal operation a very small quantity of tritium permeates through the steam generator tubing (diffusion).
The permeation occurs with the hydrogen and deuterium escaping from the PHT system. Due to this diffusion, a small quantity of tritium will be present in the steam generator water and steam ……. current tritium concentrations in the steam generator steam samples is about 3.0 x 104 Bq/Kg.
The Essay on Ways to Control Water Pollution
And each source requires an individual solution to develop a correct answer. Requiring responsibility and involvement in the problems of water pollution, every human who lives on this planet needs to become knowledgeable about their local water resources. Ways to control water pollution should be something everyone practices in order to combat harmful wastes which eventually end up in sewage ...
– during normal operation when there is no D2O leakage, no noble gases or fission products will be found in the secondary side water (S/G, feedwater or steam).
•
•
This changes when there is a leakage of PHT water through the steam generator tubing. When a leakage occurs, the secondary side will have some noble gases, fission products and increased tritium concentrations.
Slide 22