IR 05000269/1995013
| ML16154A813 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/11/1995 |
| From: | Decker T, David Jones NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16154A812 | List: |
| References | |
| 50-269-95-13, 50-270-95-13, 50-287-95-13, NUDOCS 9507260123 | |
| Download: ML16154A813 (7) | |
Text
r REG 0q UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W., SUITE 2900 ATLANTA, GEORGIA 30323-0199 July 14, 1995 Report Nos.:
50-269/95-13, 50-270/95-13, and 50-287/95-13 Licensee:
Duke Power Company 422 South Church Street Charlotte, NC 28242 Docket Nos.:
50-269, 50-270, License Nos.: DPR-38, DPR-47, and 50-287 and DPR-55 Facility Name: Oconee 1, 2, and 3 Inspection Conduted: June 19-23, 1995 Inspector:
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77/
D. W. Jon6V Date Signed Approved by:__________
7__
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T. R. Decker, Chief Dte Signed Radiological Effluents and Chemistry Section Radiological Protection and Emergency Preparedness Branch Division of Radiation Safety and Safeguards SUMMARY Scope:
This routine, announced inspection was conducted in the areas of primary and secondary water chemistry, control room emergency ventilation systems, and audit Results:
No violations or deviations were identifie The licensee had complied with the requirements for reactor coolant chemistry and had implemented, with a few minor exceptions, the EPRI guidelines for PWR primary.and secondary water chemistry (Paragraph 2).
The licensee had complied with the operational and surveillance requirements for the control room emergency ventilation systems (Paragraph 3).
The licensee had complied with the TS required program for conducting audits of station activities (Paragraph 4).
9507260123 950714 PDR ADOCK 05000269 PDR
- REPORT DETAILS Persons Contacted Licensee Employees L. Benge, General Supervisor, Chemistry t*M. Boyle, General Supervisor, Radiation Protection tE. Brown, Scientist, Radiation Protection tS. Bryant, Specialist, Radiation Protection
- E. Burchfield, Manager, Regulatory Compliance t*W. Elliott, General Supervisor, Chemistry t*B. Foster, Manager, Safety Assurance
- J. Hampton, Vice President
- G. Hamrick, Manager, Chemistry K. Louvin, System Engineer, Systems Engineering
- D. Nix, Licensing Coordinator, Regulatory Compliance B. Norris, General Supervisor, Chemistry
- B. Peele, Station Manager
- G. Rothenberger, Superintendent, Operations T. Saville, Manager, Nuclear Engineering t*J. Smith, Licensing Coordinator, Regulatory Compliance t
B Twiggs, Manager, Radiation Protection tE. Wehrman, Scientist, Radiation Protection J. Verbos, Senior Engineer, Nuclear Engineering Other licensee employees contacted included engineers, technicians, and office personne Nuclear Regulatory Commission
- l Harmon, Senior Resident Inspector G. Humphrey, Resident Inspector t*L. Keller, Resident Inspector tAttended entrance interview
- Attended exit intervie.
Primary and Secondary Water Chemistry (84750)
Technical Specifications (TSs) 3.14, 3.15 and 4.1.3 described the operational and surveillance requirements for reactor coolant activity and chemistry. TS 3.13 specified the maximum allowable secondary coolant activity. Reactor coolant total activity, due to radionuclides with half-lives longer than 30 minutes, was required to be maintained less than 224/E-bar microcuries per milliliter (Ci/ml)
whenever the reactor was critical. The 1-131 activity in the secondary coolant was required to be maintained less than 1.4 Ci/cc. Maximum concentration limits and sampling frequencies were specified for dissolved oxygen, chloride, and fluoride in primary coolant. Sections 5.2.1.7 and 9.3.1.2 of the Final Safety Analysis Report (FSAR) indicated that guidelines for maintaining reactor coolant and feedwater quality were derived from vendor
recommendations and the current revisions of the Electric Power Research Institute (EPRI) PWR Primary and Secondary Water Chemistry Guideline Those sections of the FSAR also indicated that detailed operating specifications for the chemistry of those systems were addressed in the Chemistry Section Manua The inspector reviewed Sections 3.8 and 3.10 of the Oconee Nuclear Station Chemistry Manual and determined that they included provisions for sampling and analyzing primary and secondary coolants for the TS required parameters at the specified frequencies. Sections 3.8 and 3.10 of the manual also included provisions for implementing, with a few minor exceptions, the EPRI guidelines for PWR primary and secondary water chemistry. The corrective action guidelines provided by Sections 3.9 and 3.11 of the manual were also consistent with the EPRI guide The inspector also reviewed records and/or trend plots of analytical results for the following parameters which were either required by TSs to be monitored or were recommended by EPRI guides to be monitored as control parameters during power operation: dissolved oxygen, chloride, fluoride, E-bar, and gamma isotopic in reactor coolant; pH, hydrazine, dissolved oxygen, sodium, chloride, and iron in feedwater; and dissolved oxygen in condensate. The data reviewed were primarily generated during the period January through June 1995 for all three units. During steady state operations the reactor coolant dissolved oxygen concentrations were typically <2 ppb, chloride concentrations were typically <15 ppb, and fluoride concentrations were typically <15 ppb. Those parameters were well below their respective TS limits of 100 ppb, 150 ppb, and 150 ppb. The activity of the reactor coolant for all three units was also well within its TS limit of 224/E-bar. The other parameters selected for review were generally maintained within the EPRI guideline The licensee's TSs did not include a limit for reactor coolant specific activity in terms of dose equivalent iodine-131 (DEI) but Sections 3.10 and 3.11 of the Chemistry Manual specified sampling frequencies, administrative limits, and corrective action guidelines for reactor coolant DEL. (For reference, the standard TS limits for reactor coolant specific activity are DEI -stCi/gm and gross specific activity ad00/E-bar ACi/gm.) Analytical results and trend plots of DEI for the period March 1994 through June 1995 were reviewed by the inspector. The Unit 1 coolant DEI was typically 0.015 tCi/ml prior to the May-June 1994 outage. Following the outage, the DEI exhibited an increasing trend from 0.004 /ACi/ml to 0.008 /ACi/ml. When at full power steady state operations the Unit 2 coolant DEI ranged from <0.03 ttCi/ml to 0.1 ACi/ml during March through July 1994. During August and September 1994 the Unit 2 coolant DEI was typically 0.13 /ACi/m Following the October-November 1994 outage the Unit 2 coolant DEI was
<0.009 /Ci/ml. Significant changes in the Unit 3 coolant DEI indicated that there had been several possible fuel cladding failures during the fuel cycle which ended in June 1995. The following are some examples of such indications. In early April 1994 the DEI increased from
<0.05 /Ci/m1 to -0.15 uCi/m In late April and early May 1994 the DEI increased from <0.10 MCi/m1 to -0.21 MCi/ml. In late June 1994 the DEI increased from <0.15 MCi/ml to -0.25 /Ci/ml. On July 7, 1994, the DEI spiked to 6.55 uCi/m1 during a reactor trip. Following that trip the DEI was generally greater than 0.2 ACi/ml until the end of the fuel cycle in early June 1995. During the outage the fuel from that cycle was ultrasonically tested to identify the defective (leaking) fuel rods. The licensee identified a total of 22 defective fuel rods distributed among 16 fuel assemblies. Most of those assemblies had just completed the first of their usual 3 fuel cycles, therefore, the licensee was replacing the defective fuel rods in most of those fuel assemblies prior to reloading them into the reactor vessel for their next fuel cycle. As of the last day of this inspection the licensee indicated that the defective fuel rods had been replaced in 11 of the 16 fuel assemblies and work to replace defective fuel rods in 3 other fuel assemblies was continuing. The licensee further indicated that the other 2 of those 16 fuel assemblies would not be used in the next fuel cycle. An investigation into the failure mechanism which caused the fuel rods to leak radioactive fission products into the reactor coolant was also being conducted by the licensee and their fuel vendor. As of the end of this inspection the failure mechanism had not been identified. The licensee was requested to provide the results of their investigation to the NRC. This issue will be reviewed during subsequent inspection The inspector discussed with the licensee a prolonged problem with main feedwater nozzle fouling in the Unit 2 A steam generator (SG). The licensee indicated that the integrated control system (ICS) normally maintains the differential pressure (dp) across the A train feedwater control valve at 35 pounds per square inch (psi). When the main feedwater nozzles in the A SG became fouled, the ICS responded by increasing the feedwater system pressure in both trains in order to maintain that dp across the A train feedwater control valve. Due to the cross connection between the A and B feedwater trains, the dp across the B train control valve increased significantly above the normally expected 35 psi. The dp across the B train control valve began increasing during 1993. Prior to the April May 1993 refueling outage the dp was approximately 40 psi. Following that outage the dp gradually increased from 45 psi to 70 psi in April 1995. During a forced outage in May 1995 the licensee removed one of the nozzles from the Unit 2 A SG for examination. The licensee found that particulate material was deposited in most of the 0.188 inch diameter holes in the nozzle and had reduced the effective diameter of the holes to approximately 0.15 inches. Qualitative analysis of a sample of the particulate material indicated the it was composed of magnetite (Fe304). Based on those results the licensee determined that chemical controls for the feedwater should be used to control and/or reduce the magnetite fouling. The chemical additives and concentrations selected for use were 1.5 ppm ammonia, 1 ppm dimethylamine, and 1 ppm of a mixture of dimethylamine and trimethylamine. The licensee plans to perform further examination of the Unit 2 feedwater nozzles during the next refueling outage scheduled for the spring of 199 Based on the above reviews, it was concluded that the licensee had complied with the requirements for reactor coolant chemistry and had implemented, with a few minor exceptions, the EPRI guidelines for PWR primary and secondary water chemistr No violations or deviations were identifie.
Control Room Emergency Ventilation Systems (84750)
Technical Specifications (TSs) 3.15 and 4.12 described the operational and surveillance requirements for the control room emergency ventilation systems. The common control room for Units 1 and 2 and the Unit 3 control room each had a dedicated system. Each system had two separate trains which included outside air booster fans with prefilters, HEPA filters and activated charcoal filters. When the reactors were above hot shutdown conditions the systems were required to be capable of maintaining a positive pressure within the control room, and both outside air booster fans and both filter trains within a system were required to be operable. Action statements were provided for conditions in which one or both trains were inoperable. Operability tests of the systems were required to be performed quarterly. The operability tests included external visual inspection, air flow measurements, pressure drop measurements across the filters, one hour operation of the fans, and functional testing of all louvers. On a refueling frequency, the licensee was required to demonstrate that the systems could maintain a positive pressure in the control rooms and to perform leak tests on the HEPA filters and the charcoal filters. The leak testing media were specified as DOP for the HEPA filters and freon for the charcoal filter This area was previously inspected on October 18-22, 1993, (reference Inspection Report Nos. 50-269, 270, 287/93-27). During that inspection the licensee indicated that a modification was planned to replace the ductwork in an inaccessible ventilation shaft between the ventilation equipment room and the Units 1 and 2 common control room. That modification was necessary to correct a problem found following a failed control room pressurization test. Test results indicated that the emergency ventilation system for the Units 1 and 2 common control room could not maintain a positive pressure in the control room. The licensee discovered a disconnected joint in a section of the ductwork located within the ventilation shaft and the pressurized air was escaping from the emergency ventilation system. The joint was temporarily repaired until higher quality ductwork could be installed in the ventilation shaft. During this inspection the inspector toured the mechanical equipment rooms in which the ventilation systems for the Units 1 and 2 common control room and the Unit 3 control room were located. The licensee's cognizant system engineer located and identified, for the inspector, the major components of the systems, including the fans, filter banks, dampers, and the associated ductwork from the air intakes to the control room air conditioning systems. The inspector observed that the accessible components were structurally well maintained. The access doors to the Units 1 and 2 ventilation shaft were unlocked by the
licensee and the inspector verified that new ductwork had been installed. The inspector noted that the joints in the new ductwork and those in the remainder of the emergency ventilation system had been adequately sealed to prevent air leakage. The inspector also reviewed the results of pressurization tests which were performed subsequent to the modification. Those results indicated that the system could adequately maintain the control room at a positive pressur The inspector reviewed the procedures listed below and determined that they included provisions for performing the above operability and performance tests at the required frequencies. The acceptance criteria specified in those procedures for the test results were consistent with the TS requirement PT/1&2/A/0110/05A "Control Room Filter System Test" PT/3/A/0110/05A
"Control Room Filter System Test" PT/1&2/A/0110/15
"Control Room Pressurization" PT/3/A/0110/15
"Control Room Pressurization" PT/1&2/A/0170/03
"Control Room Pressurization System Test" PT/3/A/0170/03
"Control Room Pressurization System Test" The inspector also reviewed selected records for the above tests and determined that the tests were being performed at least as often as the TS required frequencies. The test results indicated that the equipment had met the acceptance criteria delineated in the procedure Based on the above reviews and observations, it was concluded that the licensee had complied with the above operational and surveillance requirements for the control room emergency ventilation system No violations or deviations were identifie.
Audits (84750)
TSs 6.1.3.4 and 6.1.3.5.d required the licensee to perform audits of station activities, under the cognizance of the Nuclear Safety Review Board, and to forward the audit reports to licensee management within 30 days of completion of each audit. The audits were required to encompass, in part, the following: the conformance of station operation to provisions contained within the TSs and applicable facility operating license conditions; the performance, training and qualifications of the station staff; the Offsite Dose Calculation Manual (ODCM) and implementing procedures; the Radiological Environmental Monitoring Program and the results thereof; the Process Control Program and implementing procedures for solidification of radioactive wastes; and the performance of activities required by the Quality Assurance Program for effluent and environmental monitorin The inspector reviewed the report for Regulatory Audit NG-94-10(ON),
dated September 1, 1994. The audit was conducted during the period August 8-23, 1994, by the licensee's Nuclear Assessment and Issues Division. The scope of the audit included an assessment of the chemistry
and radiation protection program activities. The audited areas within those programs included, in part, primary coolant system sampling, post accident sampling, TS required surveillances, gamma spectroscopic analysis, currency and accuracy of the ODCM, effluent controls, environmental monitoring, shipping cask handling procedures, chemistry and radiation protection procedures, and corrective actions. The number and characterization of the substantive issues identified by the audit were as follows: 9 findings and 2 recommendations. Pursuant to the licensee's auditing procedures, the identified issues, including corrective actions for the findings, were tracked for completion of warranted follow-up actions through the licensee's Problem Investigation Process (PIP). The inspector determined that the audit was of sufficient scope and depth to identify existing problems and that corrective actions for the identified findings were documented and resolved through the PIP. The audit results were well documented and reported to facility management in a timely manne Based on the above reviews, it was concluded that the licensee had complied with the TS required program for conducting audits of station activitie No violations or deviations were identifie.
5. Exit Interview The inspection scope and results were summarized on June 22, 1995, with those persons indicated in Paragraph 1. The inspector described the areas inspected and discussed in detail the inspection results listed above. No dissenting comments were received from the license Proprietary information is not contained in this report.