IR 05000528/1989017
| ML17304B179 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 05/04/1989 |
| From: | Garcia E, Tenbrook W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17304B178 | List: |
| References | |
| 50-528-89-17, 50-529-89-17, 50-530-89-17, NUDOCS 8905230094 | |
| Download: ML17304B179 (20) | |
Text
U.
S.
NUCLEAR REGULATORY COMMISSION
REGION V
Report Nos.
50-528/89-17, 50-529/89-17, 50-530/89-17 License Nos.
NPF-41, NPF-51, NPF-74 Licensee:
Arizona Public Service Company P.
O.
Box 21666 Phoenix, Arizona 85836 Facility Name:
Palo Verde Nuclear Generating Station - Units 1, 2 and
Inspection at:
Wintersburg, Arizona Inspection Conducted:
April 3-7, 1989 Inspected by: W~ ZT Approved by:
W.
K. TenBrook, Radiation Specialist Pr
~ r'piQ'v..
E.
M. Garcia, Acting Chief Facilities Radiological Protection Section Date Signed s/ply" Date Signed
~Summer:
Areas Ins ected:
Routine unannounced inspection of inspector followup items, radiochemical analysis, quality assurance of plant chemistry activities, chemical analysis and plant water chemistry control.
Inspection procedures 92701 and 84750 were used.
Results:
Program strengths included the licensee's control of water chemistry during mode changes, decreased chloride and sodium excursions caused by condensate polisher operations (section 3.B), improved Reactor Coolant System (RCS) chemistry instrumentation and analyses in Unit 2 (section 2), and good agreement between the licensee and NRC radiological confirmatory measurements (section 3.A).
Program weaknesses included high concentrations of dissolved oxygen in auxiliary feedwater systems during hot.standby due to oxygenation of makeup sources (section 3.B), degradation of steam generator in-line instrumentation providing annunciation (section 3.B), outlier measurements of double-blind laboratory comparison samples (section 3.B), lack of consistency between the laboratories as to the~ need for diagnostic RCS sulfate analyses (section 3.B),
and inconsistency in interlaboratory corn'parisons for radiostrontium (section 3. A).
Overall program status was satisfactory to accomplish safety functions for steam generator protection.
3905230094 390505 PDR ADOCK 05000523
DETAILS Persons Contacted Licensee
"R. Butler, Director, Standards and Technical Support
"B. Cederquist, Supervisor, Chemistry Standards
- R. Cunningham, Chemistry Lead, Unit 2
"R. Ferro, Chemsitry Manager, Unit 2
"D. Fuller, Chemistry Manager, Unit 1
"D. Goodwin, Chemistry Lead, Unit 1
"C. Gray, Acting Chemistry Manager, Unit 3
"D. Heinicke, Manager, Unit 2
"P.
Hughes, Manager, Chemistry and Radiation Protection D. Kelsey, Chemistry Lead, Unit 1
"J.
Mann, Manager, Central Radiation Protection K. McCandless-Clark, Engineer, Compliance
"J. Napier, Engineer, Compliance
"C.
Russo, Assistant Director, guality Assurance J. Santi, Chemistry Lead, Unit 2
"T. Shriver, Manager, Compliance
"W. Sneed, Radiation Protection Manager, Unit 3
. R. Sorensen, Chemistry Lead, Unit 2
"T. Warren, Consultant, Chemistry Standards USNRC D.
Coe, Resident Inspector
"Indicates attendance at Exit Meeting, April 7, 1989.
Fol 1 owu 92701 (Closed) 50-529/88-08-01 This item concerned sensitivity limits for Reactor Coolant System (RCS) chloride analyses as reflected in "less than" levels reported in chemistry logs.
Unit 2 had obtained an ion chromatograph for analysis of RCS chloride.
Calibration and measurement control data indicated that the chromatograph chloride measurement sensitivity was sufficient to identify degrading chemistry conditions prior to exceeding technical specification (TS) 4.4.6 limits.
Water Chemistr and Confirmator Measurements 84750 In-Plant Radiochemical Anal sis and Confirmator Measurements The regional mobile laboratory trailer was. brought onsite for gamma isotopic intercomparisons with the licensee's counting laboratories.
Sample types commonly analyzed for compliance with regulatory requirements were analyzed by the licensee and the NRC, and the results were compared using the NRC verification test criteria (see enclosure).
The first sample obtained was a
47mm filter of reactor coolant suspended solids.
The results of the intercomparison are presented in Table 1.
Table
Suspended Solids from 1000 ml pCi/ml pCi/ml NRC Licensee NRC Random Analyte Result Result Uncertainty Reactor Coolant Ratio:
Licensee/NRC Agreement Range Ul Cr-'51 Ul Nn-54 Ul Co-57 Ul Co-58 Ul Fe-59 Ul Co-60 U1 Ag-110m Ul Sn-113 Ul Sb-124 U1 Nb"95 Ul Zr-95 U2 Cr-51 U2 Mn-54 U2.Co-57 U2 Co-58 U2 Fe-59 U2 Co"60 U2 Ag-110m U2 Sn-113 U2 Sb-124 U2 Nb-95 U2 Zr-95 3. 26E-05 6. 58E-06 2. 71E-11 7. 82E-05 5.95E-OG 3. 17E" 05 5. 34E-07 6. 74E-07 1. 02E-05 2. 01E-05 1.'31E-05 3. 36E-05 6. 61E-06 3. 21E-07 7. 76E-05 4. 66E-06 3. OGE-05 O.OOE+00 9.74E-07 1.02E-05 1.95E-05 1. 24E-05 3 ~ 18E-05 6.70E-06 2. 60E-11 7. 85E-05 4. 83E-06 3. 19E-05 4.62E-07 6.98E-07 1.00E"05 2.00E-05 1.30E-05 3. 18E-05 6.70E-06 2. 11E-07 7. 85E-05 4. 83E-06 3. 19E-05 4.62E-07 6.98E-07 1.00E-05 2.00E-05 1.30E-05 9.20E-07 1.58E-07 4. 30E-12 3. 90E-07 3. 08E-07 3.10E-07 1.12E-07 1.05E-07 2.80E-07 2.20E-07 3.20E-07 9. 20E-07 1. 58E-07 3. 49E-08 3. 90E-07 3. 08E-07 3. 10E-07 1. 12E-07 1.05E-07 2.80E"07 2.20E-07 3.20E-07 1. 03 0. 98 1. 04 1. 00 1. 23 0. 99 1. 16 0. 97 1. 02 1. 01 1. 00 1. 06 0. 99 1. 52 0. 99 0. 97 0. 96 0. 00 1. 39 1. 02 0. 98 0. 95 0. 75-1. 33 0. 75-1. 33 0. 5-2. 00 0. 85"l. 18 0. 6-1. 66 0. 80-1. 25 0. 5-2. 00 0. 5-2. 00 0.75-1.33 0.80-1.25 0. 75-1. 33 0. 75-1. 33 0. 75-1. 33 0. 5-2. 00 0. 85-1. 18 0. 6-1. 66 0. 80-1. 25 0. 5-2. 00 0. 5-2 ~ 00 0. 75-1. 33 0. 80-1. 25 0. 75-1. 33 U3 Cr-51 3. 09E-05 3. 18E-05 9. 20E-07 U3 Hn-54 6.39E-06 6.70E-06 1.58E-07 U3 Co-57 3.04E-07 2. 11E-07 3.49E-08 U3 Co-58 7.55E-05 7.85E"05 3.90E"07 U3 Fe-59 5.02E-06 4.83E-OG 3.08E-07 U3 Co"60 3. 01E" 05 3. 19E-05 3. 10E-07 U3 Ag-110m 3. 87E-07 4. 62E-07 1. 12E-07 U3 Sn-113 6.56E-07 6.98E-07 1.05E-07 U3 Sb-124 9.94E"06 1.00E"05 2.80E"07 U3 Nb"95.
1.97E-05 2.00E-05 2.20E-07 U3 Zr-95 1.33E-05 1.30E-05 3.20E-07 0. 97 0. 95 1. 44 0. 96 1. 04 0.
94'.
0. 94 0. 99 0. 98 1. 02 0. 75"1. 33 0. 75-1. 33 0. 5-2. 00 0. 85"1. 18 0. 6-1. 66 0. 80-1. 25 0. 5-2. 00 0. 5-2. 00 0. 75"1. 33 0. 80-1. 25 0. 75"1. 33 Agreement between the NRC and licensee laboratories was very good.
Ag-110m was not identified by the Unit 2 and Unit 3 laboratories due to slightly less sensitive analyses compared to the NRC and Unit 1 analyses.
The second sample was a charcoal cartridge removed from the containment atmosphere effluent monitor, RU-1, at Unit 1.
The intercomparison of halogen activity is given in Table Table
Charcoal Cartridge pCi/ml pCi/ml NRC Licensee NRC Random Ratio:
Analyte Result Result Uncertainty Licensee/NRC Agreement Range Uj 1-131 2. 6E-11 2. 6E-11 4. 3E-12 U2 I-131 2. 4E-11 2. 6E-11 4. 3E-12 U3 I-131 2. 7E-11 2. 6E-11 4. 3E-12 1. 00 0. 91 1. 04 0. 5-2. 00 0. 5-2. 00 O. 5-2. 00 The radioiodine measurements were in agreement.
The third sample was a 1000 ml aliquot from a Unit 1 chemical waste neutralizer tank, which holds secondary system liquid wastes prior to discharge to onsite evaporation ponds..
The sample was analyzed for principle gamma emitters, and Cs-134 and Cs-137 were identified.
The Lower Limits of Detection obtained by the licensee's standard analytical procedure were compared with TS 3/4. 11. l. 1.
The LLDs obtained during the intercomparison were generally an order of magnitude more sensitive than those required.
No measurement intercomparison was performed due to the high counting uncertainties in the low-level Cs-134 and Cs-137 measurements.
The fourth sample was an aliquot of reactor coolant from Unit 2, which had been in hot standby condition for approximately twenty days.
The sample was split between the NRC and Unit laboratories.
The intercomparison results are given in Table 3.
Table
10 ml Reactor Coolant pCi/ml pCi/ml NRC Licensee NRC Random Ratio:
Agreement Analyte Result Result Uncertainty Licensee/NRC Range Ul Mn-54 Ul Co-58 U1 Co-60 U1 Cs-134 U1 Nb-95 Ul Mo"99 Ul Tc-99m U1 I"131 U1 I-132 Ul Cs-136 Ul Cs-137 U2 Mn-54 U2 Co-58 U2 Co-60 U2 Cs-134 7. 65E" 05 6. 10E" 04 1. 10E" 04 2.07E-03 3.93E-05 2. 17E-05 2. 12E-05 3.48E"04 8.74E"04 1. 12E" 04 3. 08E" 03 1. OOE-04 6. 16E-04 1. 15E-04 1.87E-03 9. 05E" 05 8. 16E-06 6. 39E-04 1. 17E" 05 l. 06E" 04 6. 70E" 06 2. 11E" 03 2. OOE-05 5. 47E" 05 7. 50E" 06 1. 40E"05 2. 69E-06 1. 57E-05 3. 02E-06 2. 87E-04 1. 01E-05 1.20E"03 1.80E-05 1.03E-04 7.50E-06 3.20E-03 2.20E-05 9. 05E" 05 8. 16E-06 6. 39E-04 1. 17E-05 l. 06E-04 6. 70E-06 2. lip-03 2. OOE-05 0. 84 0. 95 l. 04 0. 98 0. 72 1. 56 1. 35 l. 21 0. 73 1. 08 0. 96 1. 11 0. 96 1. 09 0. 89 0. 6"1. 66 0.80-1.25 0. 6"1. 66 0. 80"1. 25 0. 5-2. 00 0. 5-2. 00 0. 5-2. 00 0. 75"1. 33 0.80"1.25 0. 6-1. 66 0. 80"1. 25 0. 6"1. 66 0. 80"1. 25 0. 6-1. 66 0. 80"1. 25
U2 Nb-95 U2 Mo-99 U2 Tc"99m U2 I-131 U2 I-132 U2 Cs-136 U2 Cs-137 3. 32E-05 0.00E+00 O.OOE+00 3. 15E-04 1.56E-03 l. 10E-04 2.96E-03 5.47E-05 7. 50E-06 1. 40E-05 2. 69E-06 1. 57E-05 3. 02E-06 2. 87E-04 1. 01E-05 1.20E-03 1.80E-05 1.03E-04 7.50E-06 3.20E-03 2.20E-05 0. 61 0. 00 0. 00 l. 10 l. 30 1. 06 0. 93 0. 5-2. 00 0. 5-2. 00 0. 5-2 ~ 00 0. 75" 1. 33 0. 80" 1. 25 0. 6-1. 66 0. 80-1. 25 U3 Mn-54 U3 Co-58 U3 Co-60 U3 Cs-134 U3 Nb-95 U3 Mo-99 U3 Tc-99m U3 I-131 U3 I-132 U3 Cs-136 U3 Cs-137 8.
6.
9.
2.
3.
0.
0.
2.
1.l.
2.
36E-05 04E-04 43E-05 05E-03 14E-05 OOE+00 OOE+00 87E-04 44E"03 17E-04 86E-03 9. 05E-05 8. 16E-06 6. 39E-04 1. 17E-05 1. 06E-04 6. 70E-06 2. 11E-03 2. OOE-05 5. 47E-05 7. 50E-06 1.40E-05 2.69E-06 1.57E-05 3.02E-06 2. 87E-04 1. 01E-05 1. 20E" 03 1. 80E" 05 1. 03E-04 7. 50E-06 3 '0E-03 2.20E-05 0. 92 0. 94 0. 89 0. 97 0. 58 0. 00 0. 00 1. 00 1. 20 1. 13 0. 89 0. 6-1. 66 0. 80-1. 25 0. 6-1. 66 0. 80-1. 25 0. 5-2. 00 0. 5"2. 00 0. 5-2. 00 0. 75-1. 33 0. 80-1. 25 0. 6-1. 66 0. 80-1. 25 The NRC, Unit 1 and Unit 2 measurements of I-132 did not agree.
The inspector graphically examined the non-decay corrected activities obtained by the four laboratories versus the midpoint of the respective counting periods.
The I-132 decay behavior amongst the three licensee results conformed to the 2.3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> I-132 half-. life, while the NRC result was biased low in compariso This suggested that the NRC I-132 measurement was a marginal outlier.
The inspector and the Unit Chemistry staff discussed the presence of I-132 in the RCS given the relatively long period since reactor shutdown.
Fission product Te-132, the long-lived parent of I-132, accounted for the presence of daughter I-132 in the coolant after many days of decay.
However, Te-132 was not identified in the sample, indicating that I-132 was spiked into the coolant, while the Te-132 remained in the fuel matrix or adhered to the clad.
This conclusion was supported by the straightforward decay behavior exhibited by the I-132 measurements.
However, the Unit 1 decay corrected I-132 activity used the Te-132 parent half-life, which was inconsistent with the I-132 decay behavior observed.
Overall, the agreement between the NRC and Licensee laboratories was satisfactory for the coolant sample.
Under the given counting conditions, the Unit 2 and 3 laboratories did not identify Mo/Tc-99m based upon slightly less sensitive analyses compared with the NRC and Unit 1 laboratories.
The last sample was obtained from Unit 1 waste gas decay tank "B."
The results of the intercomparison are presented in Table Table 4 Waste Gas Decay Tank Analyte pCi/ml pCi/ml NRC Licensee NRC Random Ratio:
Result Result Uncertainty Licensee/NRC Agreement Range U1 Kr-85 2. 60E-02 2. 71E-02 1. OOE-04 0. 96 Ul Xe-131m 1.67E-04 1.80E-04 3.10E-06 0.93 Ul Xe-133 5.67E-04 4.87E-04 1.00E-06 1.16 0. 85-1. 18 0.80-1.25 0. 85-1. 18 U2 Kr-85 2. 52E-02 2. 71E-02 1. OOE-04 0. 93 U2 Xe-131m 1.67E-04 1.80E-04 3.10E-06 0.93 U2 Xe-133 5.40E-04 4.87E-04 1.00E-06 l. 11 0. 85-1. 18 0. 80-1. 25 0. 85-1. 18 U3 Kr-85 2.48E-02 2.71E-02 1.00E-04 0.92 0. 85-1. 18 U3 Xe-131m 1. 54E-04 1. 80E-04 3. 10E-06 0. 86 0. 80-1. 25 U3 Xe-133 5.42E-04 4.87E-04 1.00E-06 l. 11 0. 85"1. 18 The fission product gas measurements were in agreement.
The results from each Unit laboratory were particularly consistent with one another.
The inspector examined records of RCS activity analyses pursuant to procedure 74ST-9RC02, Rev.
0, "Reactor Coolant Specific Activity Surveillance Test,"
and TS 3/4.4.7 requirements.
RCS activity limitihg conditions for operation were not approached at any Unit during the operating cycle.
Analyses performed pursuant to TS 4.4.7 "Gross Activity Determination" included daily gamma isotopic analysis of RCS liquid, supplemented by RCS stripped gas sampling on a weekly basis.
Suspended solids samples and evaporated alpha/beta samples were also analyzed on a frequent basis.
RCS activity data was recorded on status boards for the information of the Unit staff, and was charted at Units 2 and 3.
Procedure 74ST-9RC02 contained acceptance criteria and contingency actions.
The TS 4.4.7 analytical program was satisfactory.
The inspector appraised the results -of the licensee's inter laboratory comparison program for radiochemical analysis.
Intercomparisons from the fourth quarter 1987 to the fourth quarter 1988 were reviewed.
The results were in agreement for gamma isotopic analyses.
However, some analyses for which radiochemical technique was critical did not agree.
A disagreement for Sr-89/90 analysis performed by Unit.2 was addressed by consultation and observation of laboratory technique by a representative from Chemistry Standards Department.
The subsequent intercomparison showed improved agreement.
However, a later intercomparison at a different Unit laboratory disagreed, with indications of cross-contamination of the Unit 1 sample by a Sr-90 standard.
Overall, licensee radiostrontium intercomparisons had not demonstrated consistent accuracy.
This item will be examined in a subsequent inspection (50"528/89-17-01, 50-529/89-17-01, 50-530/89"17-01)
The results of one laboratory intercomparison for tritium indicated that the sample had not been distilled prior to analysis.
This allowed an intentionally spiked interferent to bias the result.
The inspector
examined procedure 74CH-9ZZ59, Rev.
5, "Tritium," and determined that no guidance was given to the analyst as to what samples are likely to require distillation for accurate tritium analysis.
The inspector and the Supervisor, Chemistry Standards, discussed the lack of guidance in procedure 74CH-9ZZ59, and it was agreed that the procedure would be revised to include such guidance.
This change will be verified during a
subsequent inspection (50-528/89-17-02).
The licensee's program in radiochemical analysis was satisfactory to meet safety needs.
The consistency and accuracy of radiostrontium measurements was in need of improvement.
Gamma isotopic intercomparison performance was very good, given the large number of confirmatory measurements performed.
'Water Chemistr Control and Chemical Anal sis The inspector examined guality Assurance audits88-009, "Plant Chemistry," dated May 10,'988 and 89"004 "Plant Chemistry," dated March 16, 1989.
Audit 88-009 was a broad scope evaluation, including secondary water chemistry control responsibilities, postaccident sampling, personnel performance, surveillances, documentation and analytical control.
Three Corrective Action Requests were issued regarding adequacy of review of chemistry procedures and documents, acceptability of diesel specifications,
.and unauthorized temporary modifications.
The Audit also discussed frequent quality monitoring activities covering all areas of chemistry activities.
Audit 89"004 concentrated exclusively on essential spray pond system chemistry and corrosion control.
The audit ide'ntified long-standing problems with chemical addition systems, with associated frequent out-of-specification chemistry, and excessive corrosion rates.
The standing program involved batch chemical additions with subsequent mixing by system operation.
guality Assurance recommendations emphasized the need for proper chemical addition and control to reduce degradation of structural concrete, heat exchangers, and protect spray pond pumps from frequent starts.
The audit also described previous findings and corrective actiohs which had not been promptly acted upon to improve these conditions.
Both trains of the essential spray pond system must be maintained operable pursuant to TS 3/4.7.4.
guality Assurance findings in this area call into question the margin of reliability of the spray pond pumps, and the ultimate heat sink as a whole.
The completion of corrective actions for chemical addition systems will be examined in a subsequent inspection (50-528/89-17-03, 50-529/89-17"02, 50-530/89-17-02).
The inspector briefly reviewed analytical control records for various instruments, including ion chromatographs and spectrophotometers.
Control charts with actions levels were used, with calibration and control standards analyzed at appropriate frequencies.
Standards and control samples were run within the concentrations of interest.
Analytical control was well documented in logs for each instrument.
Reagents and secondary standards in the laboratory were within their
,
expiration dates.
Housekeeping was particularly good in the Unit 2 laboratory.
The inspector examined results from the analytical verification program from 1988 to the date of the inspection.
Accuracy of analyses for total
'uspended solids, sodium and sulphate were outliers.
Fluoride and copper analyses were also weak.
These results were inconsistent with the satisfactory analytical control measures observed in the laboratories.
Possible causes for outliers included errors in intercomparison sample preparation or the use of a single or dual point calibration regime unsuited to the intercomparison sample concentration.
Given the chemistry quality assurance needs of a site possessing three laboratories, the Chemistry Standards Department was arranging a custom interlaboratory comparison program with their vendor laboratory.
The inspector informed the licensee that laboratory analytical control and measurement accuracy would be evaluated by analysis of NRC intercomparison standards during a subsequent inspection.
The inspector evaluated the inventory of in-line chemistry monitors at the Unit laboratories.
The current inventory of in-line analyzers included all control variables and most diagnostic variables recommended by the Electric Power Research Institute (EPRI).
However, the aging and unreliability of some monitor s, particularly those for steam generator downcomer and steam generator blowdown, required replacement by outboard instruments without annunciation.
The Unit 1 Chemistry Manager indicated that he was preparing a plant change request to install new in-line sampling racks and instrumentation, including in-line ion chromatographs, at each Unit laboratory.
The plant change request was in draft at the time of the inspection.
The inspector will examine the progress of the licensee's in-line monitoring improvements during a subsequent routine inspection.
The inspector examined laboratory logs containing data from RCS chemistry analyses pursuant to procedure 74ST-9RCOl, Rev.
0, "Reactor Coolant System Chemistry Surveillance Test,"
and TS 3/4.6.6.
Daily analyses verified good RCS chemistry at the detection limit of the methods employed.
RCS sulfate, a EPRI-recommended diagnostic variable, was analyzed at Unit 2, but had not been addressed by the other laboratories at the time of the inspection.
RCS sulfate was not defined as a chemistry control variable by the EPRI primary water chemistry guidelines, and had not been incorporated into the l,icensee's chemistry control procedures and analytical schedules.
The inspector evaluated the system chemistry specification for lithium-boron coordinated chemistry for RCS pH control.
EPRI and the licensee's fuel vendor had approved constant elevated lithium concentrations in the RCS to increase overall pH to as high as 7.4 at low boron concentration, thereby reducing transport and plateout of activated corrosion products in the RCS.
The inspector observed that the licensee had maintained a constant pH 6.9 operation regime, rather than adopting the elevated pH progra The inspector and the Supervisor, Chemistry Standards, discussed the lithium"boron-coordinated chemistry employed for RCS pH control.
He stated that the organization's current philosophy was to maintain consistent pH concurrent with changes in boron concentration, rather than to operate at constant maximum lithium concentration until upper pH limits are reached.
The licensee asserted that constant lithium operation would result in pH changes in response to operational transients in boron concentration, and that the ensuing pH variation may offset any advantages gained by higher pH overall.
The Supervisor, Chemistry Standards, stated that his organization would evaluate industry experience with constant lithium operation further before implementation.
The inspector examined records of condensate, feedwater and steam generator blowdown chemistry analyses for the period preceding, during, and after reactor shutdown to assess chemistry control performance dur ing mode changes.
The system chemistry was compared with EPRI guidelines and procedure 74AC-9CY04, Rev.
0, "Systems Chemistry Specifications."
The mode changes were accomplished at each Unit with no chemical excursions in the secondary system chemistry requiring action.
However, the inspector noted two unusual conditions in the auxiliary feedwater system after shutdown.
First, the auxiliary feedwater was not deoxygenated, possessing a dissolved oxygen content of 500 ppb or more.
The EPRI chemistry guidelines recommend action at 100 ppb oxygen under hot RCS conditions.
Procedure 74AC-9CY04, "Systems Chemistry Specifications,"
indicated that the guideline may be waived upon drawing.
feedwater from the condensate storage tank.
Discussions with Chemistry personnel revealed that the condensate storage tank had not been provided with means for deaeration.
The Supervisor, Chemistry Standards, stated that the plant design had not addressed oxygen ingress to the condensate storage tank, since extended operation with auxiliary feedwater suction from the CST was not anticipated.
The inspector stated that this design could cause long-term corrosion in the auxiliary feedwater system and downstream portions of the feedwater piping, and that the condition would be considered a design weakness affecting plant chemistry.
The inspector also observed that the Unit 1 hydrazine concentration in auxiliary feedwater appeared to be controlled at the lower chemistry limit, rather than maintained at a somewhat higher level to scavenge a portion of the high auxiliary feedwater oxygen, consistent with limits on hydrazine decomposition to ammonia.
The inspector brought this observation to the attention of the cognizant Chemistry Lead, who agreed that the chemistry limit had been misinterpreted.
He stated that the hydrazine concentration would be reevaluated, and increased as necessary.
The inspector examined trend charts for key chemistry control parameters, as compiled by Chemistry Standards for the year 1988.
Unit 2 demonstrated slightly superior chemistry control amongst the three plants after an outage in spring, 1988.
This was chiefly due to lower trends in measured cation conductivity, sodium and dissolved oxygen.
Unit 3 chemistry performance exhibited marginally higher conductivity, sodium and sulfate levels.
These conditions were generally effects of the condensate polishing demineralizer system, which could cause
chemistry excursions after a polisher bed is returned.to service following a 'regeneration process.
An improvement in polisher operation was evident in the closing months of 1988, as measured cation conductivity, sulfate and sodium levels fell significantly.
Unit 3 measured chloride was excellent throughout.
Unit 1 was confronted by many operational transients that biased overall chemistry trending.
High levels of cation conductivity, chloride and dissolved oxygen were observed in before and after plant transients in April/May 1988.
However, through periods of relatively steady operation, Unit 1 continued to possess marginally poorer chloride, dissolved oxygen and sulfate levels on balance.
Many of these conditions were also traced to polisher operations, as well as the expected effects of reactor transients and condenser leaks.
The inspector questioned Chemistry management as to their means for assuring that improvements for polisher operation are disseminated to all Units.
The staff replied that points of contact had been established between Chemistry Standards and Operations Support, and frequent
.
chemistry interface meetings included discussions of polisher operations.
The staff also agreed that Operations Support performance in this area was improving with experience.
The Unit 2 Chemistry Manager informed the inspector that the. Unit 1 Polisher Performance Improvement Team had been instrumental in improving Unit 1 chefhistry performance.
However, Unit 2 had not received a'copy of the reports from the Improvement Team.
The Unit 1 Chemistry Manager stated that he had not put his counterparts on distribution for the Polisher Improvement Team reports.
He stated that copies would be provided to the Unit Chemistry Managers.
The licensee's program for chemistry control and chemical analysis was satisfactory to meet safety objectives for corrosion and radiation field control.
Strengths included the licensee's control of water chemistry during mode changes, decreased chloride and sodium excursions as condensate polisher operations were improved,, and improved Reactor Coolant System (RCS) chemistry instrumentation in Unit 2.
Program weaknesses included high concentrations of dissolved oxygen in auxiliary feedwater systems during hot standby due to oxygenation of makeup sources, degradation of secondary water in-line instrumentation, inconsistency between Unit laboratories as to the need for RCS sulfate analyses, and outlier measurements of double-blind laboratory comparison samples.
Exit Meetin The inspector met with licensee management on April 7, 1989 to discuss the scope and findings of the inspection.
The licensee acknowledged commitments to revise the tritium analysis procedure and disseminate the Polisher Performance Improvement Program report to all affected parties.
The inspector also informed the licensee's representatives of the plant design weakness causing high dissolved oxygen in auxiliary feedwater.
The licensee representative acknowledged this finding without further commen Enclosure Criteria for Acce tin the Licensee's Measurements Resolution Ratio
<4 4 -
8 -
16 -
51 200 200 0.4 0 5 0.6 0.75 0.80 0.85 2.5 2.0 1.66 1.33 1.25 1.18 Co arison 1.
Divide each NRC result by. its associated uncertainty to obtain the
"resolution.
(Note:
For purposes of this procedure, the uncertainty is defined as the relative standard deviation, one sigma, of the NRC result as calculated from counting statistics.)
2.
Divide each licensee result by the corresponding NRC result to obtain the ratio (licensee result/NRC).
3.
The licensee's measurement is in agreement if the value of the ratio, falls within the limits showa in the preceding table for the
~
~
~
corresponding resolution.