IR 05000397/1988013
| ML17279B066 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 05/11/1988 |
| From: | Tenbrook W, Yuhas G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17279B065 | List: |
| References | |
| 50-397-88-13, NUDOCS 8805310275 | |
| Download: ML17279B066 (15) | |
Text
U. S.
NUCLEAR REGULATORY COMMISSION REGION V
Report No. 50-397/88-13 Docket No. 50-397 License No.
NPF-21 Licensee:
Washington Public Power Supply System P. 0.
Box 968 3000 George Washington Way Richland, Washington 99352 Facility Name:
Washington Nuclear Pr'oject No.
2 (WNP-2)
Inspection at:
WNP-2 Site, Benton County, Washington Inspection Conducted:
April ?-14, 1988 Inspected by:
.
K.
en roo,
a sation pecsa sst Approved by:
,G.
P.
u s, Cie Facili e
Radiological Protection Section
~Summar:
Ins ection on A ril 7-14 1988 Re ort No. 50-397/88-13 ate sgne ate sgned Areas Ins ected:
Routine unannounced inspection of plant water chemistry contro and chemical analysis, radiochemical analysis, post-accident sampling, and quality assurance of plant chemi,stry activities.
Inspection procedures 84725 and 79701 were used.
Resu1ts:
The licensee's program in the areas of chemistry and radiochemical analysis appeared adequate to fulfillits safety function.
No items of noncompliance were identified.
8805310275 880512 PDR ADOCK 05000397
DETAILS 1.
Persons Contacted Licensee A. Alexander, Chemistry Technician
- J. Baker, Assistant Plant Nanager D. Beecher, Chemistry Foreman T. Brun, Engineer, Plant guality Assurance
- A. Davis, Radiochemist
- R. Graybeal, Nanager, Chemistry and Radiation Protection H. Hansen, Chemistry Foreman
- D. Kidder, Supervisor, Chemistry Support Group
- L. Nayne, Assistant Supervisor, Chemistry
- L. Norrison, Supervisor, Chemistry USNRC C. Sorensen, Resident Inspector, WNP-2
- Indicates personnel present at the exit interview.
2.
ualit Assurance and Confirmator Neasurements for In-Plant Radiochemical Anal sis 84725 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 compared was reactor coolant.
A sample of reactor water was obtained through the'routine sampling path, SP-B, and split between the licensee and NRC.
The results of the intercomparison are given in Table Table
Reactor Cooling Water Nuclide NRC uCi/ml NRC X Error Licensee uCi/ml Ratio
~Ran e
Na-24 Cr-51 Mn-56 Co-58 Co-60 Cu-64 Zn-65 Zn-69m Sr-92 Tc-99m Tc-101 I-131 I-132 I-133 I-134 I-135 Ba-139 1.89 E-3 1.87 E-3.
5.68 E-3 1.98 E-4 1.61 E-4 1.07 E-1 8.31 E-4 1.56 E-4 4.63 E-4 1.39 E-2 1.12 E-2 1.09 E-3 3.25 E-3 3.01 E-3 3.25 E-3 2.90 E-3 6.33 E-4 2.3 12.9 3.2 7.6 13.3 4.9 8.3 14.3 8.4 0.3 5.1 3.0 0.9 1.1 3.2 4.4 16.8 1.91 E-3 2.07 E-3 5.19 E-3 1.66 E-4 1.64 E-4 1.05 E-1 7.24 E-4 1.66 E-4 1.26 E-2 1.17 E-2 9.93 E-4 2.8?
E-3 2.92 E-3 2.77 E-3 2.67 E-3 1.01 0.75-1.33 1.11 0.60-1.66 0.91 0.75-1.33 0.84 0.60-1.66 1.02 0.60-1.66 0.98 0.75-1.33 0.87 0.60-1.66 1.06 0.50-2.00 0.60-1.66 0.91 0.85-1.18 1.04 0.75-1.33 0.91 0.75-1.33 0.88 0.80-1.25 0.97 0.80-1.25 0.85 0.80-1.25 0.92 0.75-1.33 0.50-2.00 The accuracy of the licensee's results was generally good for this sample.
The intercomparison for radioiodine activity was satisfactory, confirming that the licensee's Dose Equivalent Iodine calculations are'ased on adequate radionuclide analyses.
Two anomalies were observed.
First, the licensee did not identify Ba-139 in the sample.
The gamma ray assigned to Ba-139 by the licensee's spectrometer was rejected due to the difference between the calculated gamma energy and the Ba-139 library energy.
The energy calibration of the licensee's spectrometer appeared to be accurate.
The inspector attributed the rejection to the low activity of Ba-139 combined with the high compton background at the Ba-139 165.8 keV emission.
These conditions would tend to worsen the shape of the photopeak, possibly resulting in a miscalculation of the peak energy and subsequent rejection.
The second anomaly involved the rejection of the 1383.9 keV emission from Sr-92.
The licensee's nuclide identification software determined that the Sr-92 emission was due to Ag-110m, which also possesses an emission at 1384.3 keV, and subsequently rejected Sr-92 as a candidate.
However, both the licensee and NRC analyses conf'irmed that Ag-110m was not in the sample.
Given the apparent absence of,other interferences, the 1383.9 emission should have been assigned to Sr-92. It appeared that the nuclide identification software performed an interference correction without confirmation that the interfering nuclides were actually present.
The inspector discussed this matter with the cognizant Radiochemist.
The Radiochemist stated that software modifications were to be issued by the vendor to correct this and other problems noted by the licensee and other users in the field.
The second sample intercompared was liquid waste from an equipment drain tank.
The results are given in Table 'uclide NRC uCi/ml Table
Equipment Drain Tank Liquid NRC N Error Licensee uCi/m'I Ratio
~Ran e
Cr-51 Co-58 Co-60 Zn-65 Cs-137
'4.16 E-6 8.42 E-7 2.36 E-6 4.88 E-6 4.68 E-7 19.9 18.5 8.3 7.4 24.2 5.77 E-7 2.87 E-7 7.11 E-7 0.14 0.50-2.00 0.50-2.00 0.12 0.60-1.66 0.15 0.60-1.66 0.50-2.00 The intercomparison for the equipment drain tank sample was poor.
The NRC identified more nuclides than the licensee due to a more sensitive analysis.
The sensitivity of the licensee analysis was adequate to meet the technical specification Lower Limit of Detection for this sample type.
The inspector reviewed the NRC and licensee analyses in an attempt to determine the cause of the disagreements.
The results of the review were inconclusive.
However, the inspector noted that the nuclides in the sample were activated corrosion products, most likely present as suspended solids.
The licensee typically added a gelling agent to liquid samples to prevent deposition or plate-out of particulate matter.
The NRC gamma analysis system was not calibrated for a gelled matrix, so the inspector requested a liquid sample for the NRC analysis.
Given the difference between the two sample matrices, partitioning of sample activity due to settling in the liquid NRC sample appeared a likely explanation for the differences observed.
Based on this hypothesis, the NRC data was reanalyzed using a filter paper geometry to simulate particulates deposited on the bottom of the sample container during
.counting.
The results agreed with the licensee's analysis of the liquid, supporting deposition as the mechanism responsible for the disagreement.
An additional liquid waste sample was obtained from the floor drain tank.
The sample contained very little activity.
However, I-131 was identified by both the licensee and the NRC.
The results are presented in Table 3.
Table
Floor Drain Tank Liquid Nuclide NRC uCi/ml NRC W Error Licensee uCi/ml Ratio
~Ran e
I-131 5.33 E-8 15.2 4.22 E-8 0.79 0.50-2.00 The intercomparison was acceptable for the second liquid sample.
Pretreatment offgas from the main condenser steam jet air ejector was intercompared.
The NRC sample container was connected to the offgas sample flow, while the licensee sampled offgas using a septum vial.
Difficulties were encountered in obtaining the NRC sample, including water intrusion into the sample container and loss of sample through improperly positioned stopcock valves.
The final offgas sample obtained
was intercompared with the licensee analysis.
The results are given in Table 4.
Table
s Steam Get Air Ejector Offgas Nuclide NRC uCi/ml NRC N Error Licensee uCi/ml Ratio
~Ran e
Kr-85m Kr-87 Xe-133 Xe-135 Xe-135m Xe-138 4.05 E-3 1.50 E-2 6.87 E-3 2.26 E-2'.17E-2 9.58 E-2 0.9 1.4 1.6 0.5 1.0 1.3 7.61 E-3 2.77 E-2 1.44 E-2 4.45 E-2 1.29 E-1 1.60 E-1 1.88 0.80-1.25 1.85 0.80-1.25 2.10 0.80-1.25 1.97 0.80-1.25 1.57 0.80-1.25 1.67 0.80-1.25 The results for the final offgas sample were poor.
The licensee's data were confirmed on a second detector system.
Given the difficulties encountered in sampling the offgas system for the NRC, the inspector and the licensee discussed possible problems in the sampling process employed.
The Chemistry Supervisor and the inspector agreed that the condenser vacuum could draw a substantial amount of sample from the NRC container if the stopcock valves were not closed in correct sequence.
After discussing the difficulties encountered in obtaining satisfactory intercomparison samples of liquid waste and gaseous waste, the inspector and the licensee agreed to devote special attention to split sampling and analysis methods involving these media in a future inspection.
This matter will be tracked. as a followup item (50-397/I'88-13-01).
A 47 mm particulate filter and standard charcoal cartridge were obtained from the plant vent sampling system, REA-SR-27, and analyzed by both the NRC and licensee.
The results of the filter paper intercomparison are presented in Table 5.
Table
Plant Pent Particulate Filter Nuclide NRC uCi/ml NRC N Error Licensee uCi/ml Ratio
~Ran e
Na-24 Cr-51 Co-58 Co-60 Zn-65 Tc-99m I-131 I-133 2.44 E-13 1.93 E-12 4.14 E-13 6.25 E-13 1.51 E-12 5.86 E-13 7.18 E-13 4.06 E-13 17.3 14.9 11.5 8.3 9.9 4.1 6.1 12.6 2.94 E-13 1.94 E-12 4.02 E-13 4.90 E-13 1.68 E.-12 9.81 E-13 6.95 E-13 3.86 E-13 1.20 0.50-2.00 1.01 0.50-2.00 0.97 0.60-1.66 0.78 0.60-1.66 1.11 0.60-1.66 1.67 0.75-1.33 0.97 0.75-1.33 0.95 0.60-1.66 The intercomparison for the particulate filter sample was generally satisfactory.
The licensee and NRC values for Tc-99m were in disagreement due to the different half-life assumptions in the respective nuclide libraries.
The inspector had constructed the NRC nuclide library
assuming that Tc-99m is present in transient-equilibrium with its parent, Mo-99, and decays with the Mo-99 half life, 66 hours7.638889e-4 days <br />0.0183 hours <br />1.09127e-4 weeks <br />2.5113e-5 months <br />.
The licensee employed the actual Tc-99m half life of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The inspector informed the Assistant Chemistry Supervisor of the cause of the disagreement during a joint review of the analytical data.
The results of the charcoal cartridge intercomparison are presented in Table 6.
Table
Nuclide I-131 I-133 Plant Vent Charcoal Filter Cartridge NRC uCi/ml NRC X Error Licensee uCi/ml Ratio
~Ran e
4.41 E-12 2.2 3.76 E-12 0.85 0.75-1.33 1.28 E-12 5.9 9.54 E-13 0.75 0.75-1.33 The agreement for the charcoal cartridge sample was adequate.
The inspector reviewed the licensee's quality control (gC) of radioanalytical instrumentation.
Internal proportional counters were checked daily for alpha and beta response and background per Plant Procedures Manual (PPM) 12.8.3 and 12.8.6.
'The results of the gC measurements were recorded on control charts.
Records of efficiency determinations were also reviewed.
The response of the instruments to gC checks and calibrations was satisfactory.
The inspector reviewed quality control checks for the sodium iodide well counter.
Counter background and response checks were performed daily per PPM 12.8.4.
Source response checks were charted and instrument response was acceptable.
Well counter efficiency calibrations were documented at multiple energies.
Gamma spectrometer energy calibration, resolution and response were checked daily and control charts were maintained for each gC parameter.
Monthly background checks were performed.
Several detector-geometry combinations were undergoing initial efficiency calibrations and verifications at the time of the inspection.
However, the inspector noted that many of the efficiency calibrations employed by the licensee had been performed as early as November, 1985, without subsequent calibration checks or recalibration using multiple nuclide sources.
Annual recalibration or calibration verification using multiple gamma energies is discussed in Regulatory Guide 4.15, INPO Practice CY-701 and ANSI N42.14.
The inspector examined records from the third and fourth quarter, 1987 radioanalytical cross check program.
Results 'for various solid, gaseous and liquid samples were consistently in agreement.
One instance was observed where a nuclide was identified by the licensee but was not actually present in the sample.
The licensee investigated this anomaly.
The inspector reviewed five quality assurance surveillance reports (gASR)
in the chemistry area.
Four gA Deficiencies were identified.
(SAR 2-87-034 contained a deficiency concerning
CFR 20.201 survey
requirements for steam jet air ejector offgas sampling.
There had been no provision for surveys to determine radiation hazard to chemistry personnel during offgas sampling, when area radiation levels could increase.
gA closed the deficiency based upon a repositioning of local area monitor RM-16 in the sampling area, visible to personnel performing sampling operations.
ASAR 2-87-290 contained a deficiency concerning failure to comply with the provisions of PPM 12.7.3 involving conductivity cell constant determination and date label requirements.
Monthly surveillances of conductivity cell constants had not been performed at the required frequency and proper label information had not been affixed to the cells.
The deficiency was closed upon a determination of each cell constant and proper documentation and cell labeling.
An evaluation of conductivity history during the period when the surveillance was overdue did not reveal any violations of chemistry technical specifications.
gASR 2-87-286 contained two deficiencies.
The first involved several discrepancies and unexplained entries in instrument logbooks.
PPM 12.1.1 states that "log books will be kept...with entries made for all pertinent instrumental events."
The auditor found that instruments were not declared inoperable in the logbooks following failed (}C tests.
Also, instrumental parameters were changed without notation in the appropriate instrument logbook.
As part of the licensee's corrective action, technicians were required to review instrumental procedures with special emphasis on logkeeping and quality control.
The second deficiency in gASR 2-87-286 involved failure to establish a
predetermined schedule of calibration frequencies for radioanalytical instrumentation.
The auditor reported that calibrations of gamma spectrometers and gas flow counters were not scheduled in plant procedures, while industry and regulatory guidance recommended annual recalibrations or calibration checks.
The substance of this deficiency was similar to the inspector's independent observations concerning recalibration of germanium detectors.
The auditor closed the deficiency based on discussions with the chemistry staff regarding the adequacy of the quality control procedures.
The substance of the discussions was not documented in the closure.
However, the auditor agreed with the Chemistry Supervisor that the applicable procedures for detector recalibration were adequate if performed as written.
The inspector reviewed the procedures for radioanalytical instrumentation and discussed instrument recalibrations with the chemistry staff and the cognizant gA auditor.
The licensee had generally accepted the adequacy of daily response checks and analytical blind intercomparisons to determine changes in instrument calibration meriting recalibration.
The inspector agreed that the gC tests should reveal anomalies under most circumstances.
However, the inspector noted that several guidance documents recommended annual multiple nuclide calibration checks in addition to daily quality control checks.
Multiple nuclide checks were recommended to identify subtle instrumental changes that might not be discovered in daily checks involving only one or two energies of interes The licensee did not explicitly commit to any changes as a result of the inspector's observations.
However, the Chemistry Super visor stated he would be amenable to annual recalibration of radioanalytical instruments.
The inspector informed the licensee that this matter would be tracked as a followup item (50-397/88-13-02)
to assess the licensee's response to the inspector's concerns regarding recalibration schedules given the guidance documents cited and the closed gASR deficiency.
The inspector examined records of post-accident sampling system (PASS)
surveillances for February and March, 1988.
The former test was a valve operability check only.
The latter test incorporated gamma isotopic intercomparisons between the PASS sample and routine sample.
Gamma isotopic activities for non-volatile nuclides compared adequately with routine reactor water samples.
Dissolved oxygen analyses also compared adequately.
In the areas inspected, the licensee's program for in-plant radiochemical analysis appeared adequate to fulfillits safety objectives.
No violations or deviations were identified.
The inspector observed non-standard practices in the area of radioanalytical instrument calibration frequency.
Li ht Water Reactor LWR Chemistr Control and Chemical Anal sis 79701 The overall scope of the licensee's chemistry control program was described in PPM 1.13.1,
"Chemical Process Management and Control."
This procedure contained chemistry control parameters and action levels for reactor water, feedwater/condensate and control rod drive water at various operational conditions.
The procedure also contained limits for other plant water systems, including circulating water, fuel pool, plant drain systems, cooling systems and makeup water treatment influent.
The inspector compared the control parameters and action levels contained in PPM 1.13.1 to the industry BWR chemistry control guidance for reactor primary water systems.
In these areas, the licensee's procedure was substantially similar to the industry guidelines.
The chemistry control procedures also addressed water systems that could serve as sources of impurity ingress to the reactor coolant system.
The inspector reviewed laboratory analyses and chemistry trends for the period 11/I/87 to 1/29/88 to verify implementation of chemistry control procedures for reactor water conductivity, chloride and silica, and feedwater conductivity.
The following power operation conditions were observed:
Parameter Reactor Water Conductivity Reactor Water Chloride Reactor Mater Silica Feedwater Conductivity Action Level I 0.20 uS/cm 20 ppb 100 ppb 0.07 uS/cm Conditions Observed 0.16 to 0.22 uS/cm typical.
Spikes coincident with shutdowns.
2-8 ppb typical, Spikes coincident with shutdowns.
Several cycles between 40-100 ppb.
Spikes coincident with shutdowns.
0.06 typical.
Spikes coincident with shutdowns.
The inspector and the Chemistry Supervisor discussed the plant operating history for the period reviewed.
Intrusion of circulating water to the main condenser had had a significant effect on reactor water chemistry.
In addition, condenser tube wear and damage, and the operational chemistry problems resulting from circulating water intrusion were the principle reasons for the plant shutdowns observed.
The cycles observed in reactor water silica were indicative of buildup, breakthrough and changeout of condensate filter/demineralizers.
Chemistry conditions above action level 1 were promptly mitigated or otherwise followed by an orderly plant shutdown.
The inspector did not observe any instances of operation above action level 1 for periods longer than the administrative limits.
The inspector and the Chemistry Support Group Super visor discussed the problems observed in the main condenser and corrective actions that were under consideration.
The licensee explained that the condenser tubes had experienced water impingement from damaged baffles.
In some cases the baffles had broken and impacted the tubes.
A Technical Evaluation Request (TER 88-103)
had been submitted to the licensee's engineering staff to evaluate long term means to prevent water impingement on condenser tubes.
The licensee stated that the most likely corrective action would be redesign of baffles and installation of new baffles and deflectors in the condenser.
The inspector and the Chemistry Support Group Supervisor also discussed the status of hydrogen water chemistry.
The licensee had completed a
preliminary evaluation of hydrogen water chemistry and had declined to implement the program until further evaluations were completed.
The chief considerations behind the decision were that area dose rates would increase due to increased N-16 in main steam, possible fuel vendor warranty considerations, program cost, lack of a regulatory mandate for the program, and the absence of signs of intergranular stress corrosion cracking (IGSCC) at the time of the preliminary evaluations.
Also, the plant has undergone Induction Heating Stress Improvement (IHSI), which provides additional protection against IGSCC.
The licensee's Hydrogen Water Chemistry (HWC) Task Force recommended that the BWR chemistry guidelines be aggressively followed, that the industry experience with HWC be closely monitored, and further plant-specific evaluations of HWC be performed using computer models.
At the time of the inspection the licensee had determined to install sampling and injection points for a
"mini-test" of HWC under plant specific conditions, pending a final decision to implement the test.
Zinc addition to the reactor coolant system has been recommended for some BWRs by the licensee's reactor vendor to passivate cobalt and thereby prevent cobalt plateout on out-of-core surfaces such as recirculation system piping.
Given that the licensee's plant employed admiralty metal condenser tubes, zinc addition was not a consideration in the water chemistry program.
The inspector reviewed laboratory records of quality control checks for non-radiological analytes.
The atomic absorbtion spectropho'tometer had been calibrated weekly prior to each session of sample analyses with standards at three concentrations covering the range of interest per PPM 12.7.1.
The calibrations were followed by 1-5 ppm check standards for each metal.
Analytical balances were recalibrated daily per PPM 12.7.5.
The inspector verified that daily standard checks were performed on the ion chromatograph per PPM 12.7.8.
The inspector reviewed the results from analytical gA blind samples supplied to the licensee's laboratory by an outside vendor.
The third and fourth quarter, 1987, samples included sodium pentaborate, chloride, silica, iron, copper, nickle and chromium.
Results were generally within the +105 agreement criteria; and analyses out of agreement were investigated.
The inspector noted improved accuracy for several analyses between the third and fourth calendar quarters.
Within the areas inspected, the licensee's program for water chemistry control and analysis appears to be adequate to fulfillits safety objectives.
Plant operations appear to have been conducted with a sensitivity to chemistry control and mitigation of environments condusive to IGSCC.
Exit Interview The inspector met with licensee management to inform them of the scope and findings of the inspection.
The licensee was informed that no items of noncompliance were identified and two,followup items would be initiated.
Licensee'anagement was,informed that chemistry department practices in the area of radioanalytical instrument calibrations would be tracked by the inspector as a followup item pending reassessment of said practices by the chemistry staf "
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 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).
3o The licensee's measurement is in agreement if the value of the ratio
,
falls within the limits shown in the preceding table for the corresponding resolution.