ML17341A692
| ML17341A692 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 11/21/1979 |
| From: | FLORIDA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML17341A684 | List: |
| References | |
| NC-93, NUDOCS 8112080236 | |
| Download: ML17341A692 (6) | |
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FLORIDA POMER
& LIGHT COMPANY TURKEY POINT UNITS 3 AND 4 NUCLEAR CHEMISTRY PROCEDURE NC-93 NOVEMBER 21 1979
1.0 Tlrle
DETEE1INATION OF FREE HYDROXIDE CONCENTRATION 2.0 A
royal and List of Effective Pa es:
- 2. 1
~Aroue1:
Consultant Consultant Radiochemis Tech Supv Plant Supt-Nuc Date Date Date Date Date Zo 7 Approved by Pl nt Nuclea afety Committee Date 2.2 List of Effective Pa es:
~Pa e Date 11/21/79 3.0
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Date 11/21/79
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Date ll/21/79 11/21/79 Monitoring of free hydroxides is important to determine the potential for caustic embrittlement in the steam generators.
The free hydroxide test will be performed on designated days when the following criterion.is met:
3.2
~pur oee:
[Na+]ppm 0.05 x S.G. Cation Conductivity (pmhos)
The purpose of this procedure is to provide laboratory personnel with an approved method for'determining free hydroxide concentration.
I
- 3. 3 Acce tance Criteria:
'I The free hydroxide concentration should be maintained below the Westinghouse recommended limit for AVT chemistry control.
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NUCLEAR CHEHXSTRY PROCEDURE NC-93, PAGE 2 DETERMINATION OF FREE HYDROXIDE CONCENTRATION 11/21/79
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4.0 Instructions
- 4. 1 ~Aaraeus:
To insure that the necessary accuracy is obtained in this procedure certain specialized apparatus are required:
4.1.1 Digital pH meter using dual electrodes.
4.1.2 Piston Buret (See NC-91 part 4.0 for operating instructions).
4.1.3 A titration beaker with a large stopper having openings for electrodes-and an inlet and outlet for purge gas (argon).
4.2 Standardization of H2S04 4.2.1 Prepare approximately one liter of -"0.002N sulfuric acid as described in "Preparation of Reagents" Nuclear Chemistry Turkey Point.
4.2.2 Standardize the boric'cid titration pH meter as described in NC-20.
4.2.3 Pipette 50 ml of the =0.002N H2S04 into a 100 ml beaker.
4.2.4 Titrate with the NaOH standard (used in boric acid titrations) to:.pH 7.0
+;05.." Stir the 'solut'ioii'during the titrati'on"with'a'agnetic" stirrer.
'==.
4.2.5 Use the following calculations to determine the N of H2S04.
OH Normalit of H3BO3 x Volume H3B03'.2.5.1 Normality of NaOH =
Volume NaOH:
The normality of 100 ppm H3B03 = 0.009547 for boric acid titration using. mannitol (0.009547)'
(25 ml H3B03)
Normality of NaOH ~
Volume NaOH 4 2 5 2 N
1 f H SO ml NaOH titrant x Normalit.of NaOH Volume H2S04 (50 ml) 4.3 Pre aration of H meter to be used in the h droxide titration 4.3.1 Soak the electrodes overnight in deionized water or in a buffer solution with pH 4.01.
4.3.2 Standardize the pH meter with pH 5.0 buffer solution (see NC-20).
4.3.3 Introduce the argon blanket into the titration beaker using a con-tinuous purge. from the argon line located in the cold lab.
4.4
~Sam lin 4.4.1 Purge each 200 ml volumetric flask to be used for sampling with argon by inserting a piece of tubing from the argon gas line to the bottom of the flask.
Purge the flask with argon for "-30 seconds.
Withdraw the tubing and immediately stopper the flask.
Proceed to the sample location.
NUCLEAR CHEMISTRY PROCEDURE NC-93, PAGE 3 DETERMINATION OF FREE HYDROXIDE CONCENTRATION 11/21/79 4.4.2 Fill the volumetric flask to the top with sample and stopper immedi-ately to minimize air contamination.
Also draw a second sample for NH3 and N2H4 analyses in an appropriate polypropylene. container.
4.4.3 Allow the samples to cool to room temperature.
4.4.4 Adjust the volume in the flask to exactly 200 ml and pour into the titration beaker.
Continue the argon purge as in step 4.3.3.
4.4.5 Note the temperature and adjust the pH meter accordingly.
4.4.6 While stirring with the magnetic stirring apparatus, titrate the:
sample using the piston burette.
Add titrant in 1 ml increments.
4.4.7 Begin recording the pH for each incremental addition of the acid upon achieving a pH of "-5.0. Continue titration until the pH is approximately 4.35.'hree to six data points between pH 5.0 and pH 4.35 should have been recorded.
4.4.8 4.4.9 Plot the data points recorded in 4.4.7 on the semi-antilog pH paper supplied by Westinghouse.
Back extrapolate with a straight edge to 7.0 to determine the titration endpoint.
See Appendix I for an example data sheet.
Analyze the other samples obtained in step 4.4.2 for ammonia and hydrazine as described in NC-88 and NC-97.
- 4. 5 Calculations 4.5.1 Calculate the total hydroxide concentration as follows:
THC ppm (Normality of H2S04) x (ml H2SO4) x 85.0 The free hydroxide in ppm hydroxide can then be calculated by sub-tracting the amine contribution from the total hydroxide concentration (THC).
Fxee hydroxide, ppm = THC (ppm NH3) (0.53 x ppm N2H4) 4.5.2 Record the results in the appropriate log books.
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~~0 ll/2l/79 FLORIDA POWER
& LIGHT COMPANY TURKEY POINT UNITS 3 &1D 4 NUCLEAR CHEHISTRY PROCEDURE NC-93 "
APPENDIX I II
'educed copy for example only I
I page 4
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