Plant Operating Standard

PW-51 Water Quality

Primary System

A. Demineralizer Influent
- 1. The demineralizer influent must be sampled daily while the reactor is subcritical.
  - a. Determine cation conductivity daily (Specification - 6 mmho/cm^2 maximum)
  - b. Determine estimated dissolved solids daily. (Specification - 1.0 ppm maximum)
  - c. Determine pH twice weekly to compare with the inline instrument. A pH range of 8.0 - 9.5 is to be maintained.
  - d. Weekly, analyze for chloride. Chloride concentration is to be maintained at less than 0.1 ppm. IF the concentration exceeds 1.0 ppm the reactor is to be immediately secured and cooled down. The system must then be cleaned up prior to any further operation.
  - e. Weekly, a millipere filter check is to be made for suspended solids. (Specification - 2.0 ppm maximum).
- 2. The demineralizer influent must be sampled at least twice weekly while the reactor is critical.
  - a. Determine pH twice weekly. A pH range of 6.0 - 7.0 is to be maintained.
  - b. Direct conductivity measurements are to be made weekly. (Specification - 2.0 mmho/cm^2) maximum) to check against inline instruments.
  - c. Twice weekly determine the estimated dissolved solids. (Specification - 1.0 ppm maximum)
  - d. For chlorides, refer to paragraph 1-d above.
  - e. For suspended solids, refer to paragraph 1-e above.
- B. Demineralizer Effluent
  - 1. The conductivity should be maintained at less than 1.0 mmho/cm^2. The in-line instrumentation should be checked weekly against an analysis.
  - 2. Chloride concentration will be checked in the influent.
  - 3. A total gas analysis should be performed weekly to check on the hydrogen concentration. (Specification - 20 to 40 cc H_2 STP/liter)
  - 4. Dissolved oxygen concentration must be determined weekly. (Specification - 0.01 ppm)

Secondary System

A. Main Steam Generators
- 1. The pH of the main steam generators must be maintained in the 10.5 - 11.0 range.
  - a. Determination should be made twice per day when the unit is operating.
  - b. During wet layup, the boilers should be sampled every third day.
- 2. The solids in these units must be maintained at lowest practical level. (Specification - max - operating - 650 ppm, max.-wet layup - 1300 ppm) frequency of sampling is the same as stated in Section A-1.
- 3. The boiler water chloride concentration must be maintained at less than 1.0 ppm, with a normal concentration of 0.1 ppm.
  - a. These units may be operated for a period of 48 hours with a chloride concentration of 1.0 ppm and up to an absolute maximum of 5.0 ppm.
  - b. If at the end of 48 hours the cause of the contamination has not been determined and corrected, or if at any time the chloride concentration exceeds 5.0 ppm, the boilers must be secured and cooled down.
  - c. They must not be operated again until the cause of contamination has been found and corrected.
  - d. At any time when the chloride concentration of the boiler is above its normal range, the sulfite concentration should be increased to 2 to 3 times its normal level.
  - e. The chloride concentration should be determined daily as a check on the quantichem analyzer, while the unit is operating. If it is in wet layup an analysis is required every three days.
    Footnote: Refer to Note on page 7 for requirements when inline instruments are not operable.
- 4. The tri- and di-sodium phosphates should be maintained in the range of 100-300 ppm phosphates while units are operating and increased to 400-600 ppm during wet layup. Frequency of sampling is the same as in Section A-1.
- 5. The sodium sulfite should be maintained in the 20-30 ppm range while units are operating and increased to 50-100 ppm during wet layup. Frequency of sampling is the same as in Section A-1.
- 6. The presence of sulfites, particularly at high temperatures, precludes the presence of oxygen. However, during wet layup, it is required that the generators be circulated a minimum of eight hours each, every third day.
B. Boiler Feedwater
- 1. The pH of the boiler feedwater should be maintained in the range of 9.0 - 9.5. An analysis should be made twice per week to check on the inline instrumentation.
- 2. Solids in the feedwater should not exceed 0.5 ppm. The analyzer should be checked by a laboratory analysis weekly.
- 3. Chlorides in the feedwater must be maintained at less than 0.1 ppm. The concentration should be determined weekly as a check on the Quantichem.
C. Deaerating Feedwater Heater
- 1. While operating, the dissolved oxygen content must be maintained at less than 0.007 ppm. A weekly analysis should be made as a check of the continuous analyzer.
  - a. Seventy-two hours after a startup is allowed to deaerate the system. If this specification cannot be met in that period, proceed as in step b, below.
  - b. The following action should be undertaken if the dissolved oxygen content increases:
    - (1) Check for proper venting though the 1st stage heater.
    - (2) Check for in-leakage at the condensers and air ejectors.
    - (3) Increase the sulfite content in the boilers to protect the drums.
    - (4) Provide additional venting to the atmosphere.
    - (5) IF the above remedies fail to decrease the oxygen content, a shutdown should be made and the DFT investigated at the earliest opportunity, meanwhile remedial action should be pressed.
      [DFT is deaerating feed tank.]
  - c. When a plant shutdown extends for two weeks or longer, cleaning of the DFT nozzles is mandatory as late in the outage as possible.
- 2. During wet layup, the DFT should be samples weekly for the following:
  - a. pH (Specification - 9.0 to 9.5 range)
  - b. Solids (Specification - 1.0 ppm max.)
  - c. Chlorides (Specification - 0.1 ppm max.)
D. Main and Auxiliary Condensers
- 1. The following specifications apply to these units.
  - a. pH - 9.0 - 9.5 range
  - b. Solids - 0.5 ppm max.
  - c. Chlorides - 0.1 ppm max.
- 2. The inline instrumentation should be checked with a laboratory analysis weekly.

Auxiliary Systems

A. Intermediate Cooling System
- 1. This system should be sampled daily.
- 2. The following specifications apply.
  - a. pH - 10.0 - 11.0 range.
  - b. Solids - 2000 ppm max.
  - c. Phosphates - 100-300 ppm range.
  - d. Chlorides - 1.0 ppm max.
  - e. Chromates - 500-1000 ppm range.
    A mandatory shutdown is required if the chlorides exceed 1.0 ppm. but are less than 5.0 ppm and corrective action is not successful within 48 hours. The plant must be shut down in any case when the chlorides exceed 5.0 ppm.
- B. Cyclotherm and LP Steam Generator.
  - 1. These units, when in operation should be sampled twice daily.
  - 2. The following specification apply.
    - a. pH - 10.5 - 11.0 range.
    - b. Solids - 1000 ppm max.
    - c. Chlorides - 4.0 ppm max.
My text copyright 2020 Tommy Johnson, all rights reserved. I believe the Savannah documentation is property of MARAD or the US government.