IR 05000334/1998009
| ML20206U319 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/05/1999 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20206U307 | List: |
| References | |
| 50-334-98-09, 50-334-98-9, 50-412-98-09, 50-412-98-9, NUDOCS 9902120317 | |
| Download: ML20206U319 (24) | |
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U. S. NUCLEAR REGULATORY COMMISSION
REGION I
License Nos. DPR-66, NPF-73 Report Nos.' 50-334/98-09,50-412/98-09 Docket Nos. 50-334,50-412 Licensee: - Duquesne Light Company Post Office Box 4 Shippingport, PA 15077 Facility: Beaver Valley Power Station, Units 1 and 2
- Inspection Period: November 16,1998 through December 17,1998 January 4,1999 through January 6,1999 Inspectors: A. L. Della Greca, Senior Reactor Engineer E. H. Gray, Senior Reactor Engineer G. V. Cranston, Reactor Engincer C. W. Smith, Resident inspector Approved by: J. Yerokun, Acting Chief Engineering Programs Branch Division of Reactor Safety l
9902120317 990205 ;
PDR ADOCK 05000334 {
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EXECUTIVE SUMMARY Beaver Valley Power Station, Units 1 & 2 NRC Inspection Report 50-334/98-09 & 50-412/98-09 During the periods between November 16 and December 17,1998, and between January 4 and January 6,1999, the NRC conducted an engineering team inspection at the Beaver Valley Power Station, Units 1 and 2. The overall objective of the inspection was to assess the effectiveness of the engineering functions in providing for the safe operation of the plant. The assessment consisted of a safety system engineering inspection that focused on the Unit 2 High Head Safety injection System in its normal and emergency configurations. The evaluation also addressed the engineering effectiveness in identifying, resolving, and preventing problems.
Within the scope of review, the team's conclusions are identified below.
Enaineelngi
. No inconsistencies existed between the design documents reviewed and the descriptions in the UFSAR and other licensing documents related to the chemical and volume control and high head safety injection systems. In general, the applicable calculations were well organized and correctly addressed their objectives. [E1.1]
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In the Unit 2 de voltage drop calculation the licensee incorrectly assumed that, during steps 2 to 6 of the diesel generator loading sequence, the voltage for closing several i circuit breakers that supply power to major 4 kV safety-related loads was based on normal battery charger output voltage. This assumption did not recognize that, during that period, because of the high load demand, the battery charger would operate at limiting condition and would, therefore, be unable to provide normal output voltage.
Although subsequent licensee evaluations indicated that conservatism was available in the cable length and operating temperature, their failure to correctly analyze the performance of the battery charger under calculated bus loading conditions and to properly verify the adequacy of the calculation assumptions resulted in a violation of Appendix B, Criterion lil, Design Control. [E1.2]
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The qualified life calculation for the Unit 2 charging /high head safety injection pump ;
motor did not include margin for the post-accident temperature profile, as stated in NUREG 0588 and IEEE Standard 323, prior to its use in the calculation, and did not take into account pump operation at high flow, as indicated in the Westinghouse qualification document cited in the calculation. However, because the calculated qualified service life was well above the expected duty cycle for these pumps, the discrepancies had no safety impact on the qualification status of the motors. [E1.3]
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.The Design Change Psckages and Temporary Evaluation Reviews related to the Charging and High Head Safety injection systems, including their associated Safety Evaluations and calcu,ations, were typically well written, properly addressed the bases
- for the change, and r,orrectly evaluate the safety impact. The documents reviewed also showed an improving trend in clarity and referencing of supporting material. [E1.5]
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Within the scope of review, the applicable portions of the ac and de power, service air, and componert cooling water system, were capable of providing the resources necessary for the proper operation of the charging and high head safety injection systems. [E1.6]
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The sample documents reviewed indicated the Design Basis Documents to be comprehensive and well written, current and in use by Engineering. The UFSAR .
Verification Project had been useful in identifying and correcting discrepancies both in the UFSAR and associated documents. Discrepancies were being properly handled and entered in the plant Corrective Action Program. [E1.4 and E1.7]
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In the area of Corrective Maintenance, the current backlog of open Unit 2 Maintenance Work Requests (129) for the charging and high head safety injection (HHSI) systems was significant. However, a sampling of the open Maintenance Work Requests identified no system operability concems. The PM procedures related to the charging and HHSI
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systems were generally acceptable and the PM activities consistent with approved procedures. [E2.1]
. Engineering failed to recognize the need for circuit breaker refurbishment and did not take action to address this need until the manufacturer recommended refurbishment periods had expired by several years and breaker failures to actuate as expected had begun to occur. Also, testing of some 480V and 4160V air circuit breakers did not reflect the minimum calculated voltage for those breakers. As a result of the failures, they conducted thorough evaluations, took acceptable actions to reasonably assure the operability of the breakers, and revised the applicable test procedures to envelope calculated voltages at the breaker operating coils. This licensee-identifed and corrected violation of 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, is being treated as a Non-Cited Violation, consistent with Section Vll.B.1 of the NRC Enforcement Policy.
[E2.1]
.. Two issues affecting the charging and HHSl systems performance, i.e., the binding of Atwood & Morrill check valves, due to material incompatibility, and the gas binding of charging pump suctions, were resolved during the recent extended maintenance outage.
However, the satisfactory resolution of these issues did not occur for several years after recognition of the problem. [E2.2]
. The procedure for processing condition reports was well written and provided sufficient direction and tools for the proper administration of the corrective action program.
However, the assignment of significance levels (categories) and cause codes to the reports was not always correct, the first being sometimes lower than expected and the latter dealing primarily with the symptoms rather than the cause of the condition.
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Licensee management was aware of the program weaknesses and had already taken actions to address them through increased oversight and training of responsible engineering and management personnelin engineering fundamentals and root cause analysis techniques. [E2.3]
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The Corrective Action Review Board review of Condition Reports (CRs) provided positive insights in the problem identification, cause analysis, and corrective action process.
Good synergism existed among the board members in their consideration of the CRs and the identified corrective actions. [E2.4]
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The review of selected operation procedures associated with the Unit 2 charging and high head safety injection systems, including those for venting and operations surveillance testing of the charging pump, identified no safety issues. Similarly, no negative issues were observed in the verification of applicable valve lineups against plant configuration. [E3.1]
.- The review of selected system test procedures and test results and discussions with responsible IST test engineers indicated that the testing of the charging and high head safety injection systems was acceptable. Procedures were comprehensive and properly implemented. [E3.2] i
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The Quality Assurance (QA) organization was actively involved in plant activities and had developed a top 10 list of plant focus issues. The QA plan and verification of technical specification testing requirements was well laid out. The review performed by QA, the Operating Experience Group, and Systems Engineering indicated good self-assessment efforts by the disciplines involved. [E-7.1]
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n TABLE OF CONTENTS PAGE EXECUTIVE SU M MARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii 111. Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........... .. . ....... 1 E1 Conduct of Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 E1.1 System Design Bases and Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 E1.2 DC Voltage Drop Calculation . . . . . . . . . . -. . . . . . . . . . . . . . . . . . . . . . . . . 2 E1.3 Equipment Environmental Qualification (93809) . . . . . . . . . . . . . . . . . . . . . . . 4 E1.4 Design Basis Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . ..........6 E1.5 Design Changes (37001) . . . . . . . ........ .. ...... ..........6 E1.6 Auxiliary Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . ............ ... 7 E1.7 UFSAR Verification Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 E2 Engineering Support of Facilities and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 E2.1 Equipment Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 E2.2 Licensee Event Reports and Operating Experience . . . . . . . . . . . . . . . . . . 12 E2.3 Corrective Action Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 E2.4 Corrective Action Review Board (CARB) . . . . . . . . . . . . . . . . . . . . . . . 14 E3 Engineering Procedures and Documentation . ................. ..... . . . 14 E3.1 System Operating Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 E3.2 System Testing . . . .................... . . .. ............... 15 E7 Quality Assurance in Engineering Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 i E7.1 Self-Assessment . . . . .......... ................ .. .......... 16 l V. Management Meetings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 X1 Exit Meeting Sum mary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 i
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Report Details Summary of Plant Status During the periods between November 16 and December 17,1998, and between January 4 and January 6,1999, the NRC conducted an engineering team inspection at the Beaver Valley Power Station, Units 1 and 2. The overall objective of the inspection was to assess the effectiveness of the engineering functions in providing for the safe operation of the plant. The assessment consisted of a safety system engineering inspection (SSEI) that focused on the Unit 2 High Head Safety injection System in its normal (charging) and emergency configurations.
The evaluation also addressed the engineering effectiveness in identifying, resolving, and preventing problems. Units 1 and 2 remained at or near full power throughout the inspection period.
111. Enaineerina l
E1 Conduct of Engineering E1.1 System Desian Bases and Reauirements (93809)
a. Inspection Scope The Team reviewed the Updated Final Safety Analysis Report (UFSAR), the Technical Specifications, the Flow and Control Diagrams, Valve Operator Number Drawings (VONDs), the Design Basis Documents (DBDs), Design Change Packages (DCPs), the system Operating Manual, and applicable design calculations to ensure that the licensee properly maintained the design bases of the chemical and volume control (charging) and high head safety injection (HHSI) systems.
b. Observations and Findinas The team reviewed applicable sections of the UFSAR and Technical Specifications, associated flow, logic, and control wiring diagrams, and selected Valve Operator Number Diagrams. They found that the documents associated with the charging and HHSI systems were generally consistent among each other. Any discrepancies or inconsistencies that were being identified by the licensee as part of the UFSAR j Verification Project were being addressed and corrected according with existing !
programs. The team also determined that design changes initiated to address system l design or performance deficiencies appropriately initiated the paperwork required to j update and maintain the design and licensing basis documentation current. The system Operating Manual used by Operations was comprehensive and consistent with the ,
design documents. I Except as described in sections E1.2 and E1.3, below, the calculations reviewed were ,
well organized, appropriately identified objectives, method and computer programs used, l references, and conclusions. The calculations reviewed included 10080-N-747, which !
defines the HHSI pump performance requirements and safety injection branch line flow settings; 10080-N-702, which determined the acceptability of the HHSI pump suction temperature increase while running on mini flow without cooling water to the seal water heat exchanger; and CHS*9-0-C, which verifies adequacy of containment piping over-pressure protection.
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c. ~ Conclusions No inconsistencies existed between the design documents reviewed and the descriptions in the UFSAR and other licensing documents related to the chemical and volume control and high head safety injection systems. In general, the applicable calculations were well organized and correctly addressed their objectives.
E1.2 DC Voltaae Droo Calculation (93809)
a. Insoection Scooe The team reviewed applicable portions of the de voltage drop calculations to evaluate the acceptability of the control voltage available at the safety-related 480V and 4kV circuit breakers.
b. Observations and Findinas During regularly scheduled tests of the emergency diesel generator sequencer, the licensee experienced several breaker failures to operate as required by design and the breaker control logic (see section E2-1, below). The failures involved both safety and nonsafety-related air circuit breakers in both the 480V and the 4kV range. Responsible i system engineering personnel attributed the failures to inadequate maintenance and to the fact that the available voltage at the trip coil was insufficient to compensate for the maintenance deficiency.
The licensee had developed two de voltage drop calculations, one for each Unit. For ease of reference, the calculations included tables that identify the minimum required voltage for the proper operation of the components and the calculated available voltage.
Two sets of tables existed, one for 60-cells battery operation, and one for 59 cells, i.e.,
with one celljumpered out. For the circuit breakers that require closing following an event that includes a loss of offsite power (LOOP), the tables also identify the step in the emergency diesel generator (EDG) Ioading sequence at which the breaker is reclosed.
The intent was to recognize that, following re-energization of the battery charger, during step 2 of the EDG loading sequence, a higher voltage would be available at the battery bus and, hence, at the loads.
The team's review of the calculation tables determined that, for Unit 2 (Calculation No.
10080-E-202, Revision 1, dated July 30,1998), with 59 battery cells available, the calculated voltage at the closing coil of several safety-related 4160V circuit breakers would be slightly above the minimum required design voltage. In the case of the circuit breaker that provides power to the "B" HHSI pump (2CSH*P18), the calculated voltage was lower (89.56V) than the minimum required by design (90V). Therefore, the licensee had developed a third table that was based on less conservative assumptions. Even in this case, for the pump in question the calculated voltage was only 0.2 voit above the minimum required. The team identified no concerns with the calculation revisions made
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to develop the third table.
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Because the control voltage available to some breakers had very limited margin, the team evaluated the battery loads further. They determined that, between steps 2 and 6 of the EDG loading sequence, the electrical loads on the de bus were more than twice the rating of the battery charger. Because of the high load demand, during this period, the battery charger, operating at limiting capacity, would not be able to provide an output voltage at its normal level, as assumed by the licensee. Subsequently, the licensee confirmed that ten Unit 2 circuit breakers (four on the "A" 4kV switchgear and six on the
"B" switchgear) supplying safety-related, accident mitigating loads would receive calculated control voltages below the minimum required by the breaker manufacturer.
Unit 1 was not affected by the team's finding because the Unit 1 calculation had conservatively not taken credit for battery charger operation during EDG loading. j The ensuing operability evaluation by the licensee determined that reasonable confidence existed regarding the ability of the batteries to provide an acceptable voltage to the closing coil of the breakers. Confidence was derived from: (1) the current capacity of the batteries was in excess of 100%; (2) margin was available in the voltage drop 1 calculation due to conservative cable length and cable operating temperature assumed; (3) no breaker failures to close had been experienced during normally scheduled loss of offsite power tests; and (4) breakers usually close at voltages well below the minimum specified by the manufacturer.
Regarding the last point made by the licensee, the team observed that, because (1) the breakers had not been refurbished within the manufacturer specified period; (2) little information existed regarding loads and control voltage levels during the LOOP simulated test; and (3) closure of the breakers during the preventive maintenance (PM)
tests was conducted at 100V, rather than at the manufacturer specified minimum voltage; little confidence could be derived from the normal closing performance of the breakers. Nonetheless, for the other three reasons stated by the licensee, the team believed that breaker operability was not an immediate safety concern.
Following the inspection, the licensee provided to the team a copy of the condition report (CR) they had initiated to address the finding and the preliminary results of the revised calculation.- These results showed that, with correct cable lengths and more realistic cable temperatures applied, the available voltage at the closing coil of all but four breakers in question was above the minimum 90V specified by the manufacturer. For the other four breakers, discussions with the licensee determined that closure during the EDG loading was not required and that the available voltage at the closure demand time would be well above the minimum recommended by the manufacturer. Clarification would be provided in the revised calculation. These discussions also determined that the licensee had previously performed safety system functional inspections of the 4kV and l the 480V system, but had not identified the incorrect assumption of the de voltage drop calculation.
The licensee's failure to correctly analyze the performance of the battery charger under calculated bus loading conditions and to properly verify the adequacy of the calculation assumptions is a violation of 10 CFR 50, Appendix B, Criterion 111, Design Control. (VIO ,
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c. Conclusions In the Unit 2 de voltage drop calculation the licensee incorrectly assumed that, during steps 2 to 6 of the diesel generatorloading sequence, the voltage for closing several circuit breakers that supply power to major 4 kV safety-related loads was based on normal battery charger output voltage. This assumption did not recognize that, during that period, because of the high load demand, the battery charger would operate at-limiting condition and would, therefore, be unable to provide normal output voltage.
Although subsequent licensee evaluations indicated that conservatism was available in the cable length and operating temperature, their failure to correctly analyze the performance of the battery charger under calculated bus loading conditions and to properly verify the adequacy of the calculation assumptions resulted in a violation of Appendix B, Criterion lil, Design Control.
E1.3 Eauipment Environmental Qualification (93809)
a. Inspection Scope The team reviewed the environmental qualification status of the safety-related electrical equipment in harsh environment, associated with the high head safety injection system.
b. Observations and Findinas The team's sample review of the master list of safety-related electrical equipment in a harsh environment determined that all components evaluated and within the scope of the inspection had been included in the list. The team also determined from applicable system component evaluation worksheets that the licensee had evaluated and confirmed that such components were qualified to perform their safety function in the post-accident environment to which they were exposed at their mounting location. ,
i To address service qualified life, the team selected the high head safety injection pumps )
and reviewed a life extension calculation that had been prepared by the licensee, calculation No.10080-DQC-0040, Revision 0, dated October 8,1992. In the calculation, the licensee concluded that the pumps were qualified for approximately 48 years. This conclusion was based on the licensee's assumption that only one pump would be operated during the life of the plant and that the same pump would perform the post-accident safety function.
At Beaver Valley (BV), each unit is equipped with three pumps, only one of which is required to perform the charging and high head safety injection functions, in reality, pumps normally share the charging duty and their required service life is approximately one third of the design life of the plant (40 years). Therefore, the calculated qualified life of the pumps (48 years) was well in excess of their required duty cycle. Nonetheless, the team's detailed review of the calculation assumptions and methods identified two discrepancies of minor significance, as described below.
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Westinghouse (W), based on the generic criteria specified in their qualification plan, had
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subjected the pump motor to 210*C for 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> and calculated the combined qualified life of the three (per unit) Beaver Valley pump motors to be nine years (three years per motor) plus one year of post-accident operation. They had communicatsd this information in a letter to the licensee, dated February 16,1983. _W had also conducted another test (990 hours0.0115 days <br />0.275 hours <br />0.00164 weeks <br />3.76695e-4 months <br /> at 180*C) yielding equivalent results. Based on these tests, if the BV conditions were the same as those specified in the_W qualification plan, each pump motor or associated age-sensitive components should be replaced after three years of operation.
At BV, a category 2 plant per NUREG-0588, because the operating temperature of the motors during normal as well as post-accident operation was well below the_W testing temperature, the licensee was able to use the temperature test for both the normal and the post-accident operability period. Specifically, the licensee, using the Arrhenius regression analysis, calculated the amount of aging time at 180*C that was equivalent to a six-month aging in the BV post-accident temperature. The remainder of the_W aging time was used to calculate the equivalent life in the BV normal operating environment.
The methodology used by the licensee was acceptable, except that, as specified in NUREG-0588 and IEEE Standard 323-1974, margin should have been added to the post-accident profile, prior to calculating the equivalent aging time at 180'C. This was not done. Also, the licensee's calculation had not considered operation of the motors at maximum charging, as indicated in the 1983.W letter cited above. Consideration of these two discrepancies does impact the calculation results. However, based on team's estimates, the change in qualified life would not alter the qualified status of the pumps for the life of the plant.
The possibility of licensee's failing to include margin in other calculation was discussed with responsible engineering personnel. As a results of these discussions, the team believed the error was an isolated instance. The licensee appropriately initiated a condition report to address the team's observations. The calculation discrepancies identified by the team constitute a 10 CFR 50.49 violation of minct significance and is not subject to formal enforcement action.
c. Conclusions The qualified life calculation for the Unit 2 charging /high head safety injection pump motor did not include margin for the post-accident temperature profile, as stated in NUREG 0588 and IEEE Stand'rd 323, prior to its use in the calculation, and did not take into account pump operation % high flow, as indicated in the Westinghouse qualification document cited in the calculation. However, because the calculated qualified service life was well above the expected duty cycle for these pumps, the discrepancies had no safety impact on the qualification status of the motors.
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E1.4 Desian Basis Documents a. Inspection Scope (93809)
The team reviewed the Design Basis Documents (DBDs) for the Unit 2 chemical and volume control system and the safety injection system.
b. Observations and Findinas The Beaver Valley DBDs provide a detailed description of the functions and operation of the system and identify the applicable design documents that are part of the design basis of the system. Although the DBDs do not constitute, by themselves, the design basis of the system, when used appropriately, they provide an excellent road map to understanding the system design functions and requirements.
The team's review of the Unit 2 chemical and volume control system and the safety injection system found them to be well written and comprehensive. The team also found that they were kept current, were controlled, and were in use by design engineering. As also described elsewhere in this report, within the scope of the ongoing UFSAR Verification Project the licensee was comparing the UFSAR descriptions with the DBDs and the Operating Manual. This effort is intended to ensure consistency between design and operation documents.
c. Conclusions The team found the Design Basis Documents to be comprehensive and well written.
They also found that the DBDs were kept current and in use by Engineering.
E1.5 Desian Chanoes (37001)
a. Inspection Scooe The team evaluated the adequacy of Temporary Evaluation Reports (TERs) and Design Change Packages (DCPs), including their associated design calculations and 10CFR50.59 Safety Evaluations. The review focused on changes to the systems inspected that were performed between 1994 and 1998.
b. Observations and Findinas The team evaluated selected portions of DCPs associated with the Unit 2 charging and high head safety injection systems. The team observed that, in general, the modifications correctly addressed the bases for the change; the design change descriptions were well written and clearly identified the problem and its resolution; the safety evaluations properly addressed the safety and regulatory impact as required by 10 CFR 50.59; and selected references were accurate. The team also noted a significant improvement in clarity, format, and content of the more recent DCPs and Safety Evaluations. References and supporting information in the more recent safety evaluations were also more comprehensive.
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The calculations, where applicable, were well organized, appropriately identified the objective, background information, method used, references, description of computer programs used, if any, and the results and conclusions. As with the DCPs, the calculations showed an improving trend regarding content and clarity.
The TERs reviewed, involving essentially minor design changes, were similarly acceptable. As expected, they included a description and basis for the design change, component design equivalency evaluations, technical evaluation impact reviews,10 CFR 50.59 applicability reviews, and appropriate references.
c. Conclusions The Design Change Packages and Temporary Evaluation Reviews related to the Charging and High Head Safety injection systems, including their associated Safety Evaluations and calculations, were typically well written, properly addressed the bases for the change, and correctly evaluate the safety impact. The documents reviewed also I showed an improving trend in clarity and referencing of supporting material.
E1.6 Auxiliary Systems a. Inspection Scooe (93809)
The team reviewed auxiliary systems required for the proper operation of the charging and the high head safety injection systems. The review addressed primarily single failures and included applicable portions of the ac and dc power, service air, and cooling water systems.
b. ' Observations and Findinas To address the adequacy of the ac power required to support the operation of the
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systems inspected, the team evaluated single line diagrams and control wiring diagrams of major components in the system. The team also evaluated the quality of maintenance performed on safety-related circuit breakers in the low (480V) and medium (4160V)
voltage range. Within the scope of review, the team identifient no areas of concems with the power flow or the logic used for the control of the system components. Maintenance of circuit breakers is discussed in section E2.1, below.
Regarding de power, the team evaluated applicable portions of the de power flow, including breaker / fuse sizes. The team also evaluated the voltage available at various components and panels. As in the ac area, the team identified no concems with the power flow, the size of the protective devices. Except, as discussed in section E1.2, above, regarding the voltage drop calculation, the voltage level available at the components reviewed was acceptable.
In the service air and component cooling areas. the team evaluated the failure modes of air operated valves and the impact of a loss of cooling water to the charging pump seals.
The team found that the failures evaluated did not adversely impact the operation of the plant or prevent the accident mitigation function of the high head safety injection system.
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c.' . Conclusions I
Within the scope of review, the applicable portions of the ac and de power, service air,
. and component cooling water, were capable of providing the resources necessary for the .I proper operation of the charging and high head safety injection systems.
E1.7 UFSAR Verification Prolect -
a. Insoection Scooe (93809)
The team reviewed the scope, process flow chart, and schedule of the ongcing UFSAR Verification Project.
b. Observations and Findinas
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The licensee initiated the UFSAR Verification Project in March 1997 and had now scheduled it for completion in March 1999, for Unit 1, and June 1999, for Unit 2. The scope of the Project entails the review of 21 risk-significant systems for each unit, and is 1 based on the Maintenance Rule probability risk assessment (PRA). UFSAR information i for each of the 21 systems, including the Chapter 14 and Chapter 15 Accident Analysis for Unit 1 and Unit 2, respectively, is extracted and reviewed by the Verification Team ..
the Systems Engineers, the Design Engineers, Nuclear Safety and Licensing and
_ Operations. The process includes a comparison of the UFSAR information to key design documents, including the Design Basis Document and the plant Operating Manual.
The team's evaluation of activities related to the project and discussions with responsible licensee personnel determined that the majority of the discrepancies identified involved inconsistencies between different sections of the UFSAR and that the discrepancies were being entered in the corrective action program. The team also observed that the
. project was primarily staffed with contract engineers. The contractors, however, had substantial, previous Beaver Valley experience, both in the Nuclear steam supply and L balance of plant systems.
c. Conclusions To the extent of their review, the team concluded that the UFSAR Verification Project had been useful in identifying and correcting discrepancies both in the UFSAR and associated documents, and that discrepancies sere being properly handled and entered in the plant Corrective Action Program.
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E2 Engineering Support of Facilities and Equipment E2.1 Eauioment Maintenance a. Inspection Scope (93809)
The team reviewed a sample of open maintenance work requests (MWR) and the preventive maintenance (PM) program applicable to the charging and HHSI systems.
The team also reviewed the preventive maintenance of safety-related air circuit breakers in the low (480V) and medium (4160V) voltage range. The review addressed circuit breaker PM activities of both units. The PM program was discussed in detail with responsible engineers.
b. Observations & Findinas Corrective Maintenance The team reviewed the list of open MWRs associated with the systems inspected and evaluated the content of selected MWRs to establish the scope and significance of planned corrective maintenance and the health and readiness of the systems. They determined that the current backlog consisted of 129 open MWRs for Unit 2 only. A few of these MWRs dated back to 1993 and 1994. Although the backlog appeared to be high, the team's review of the selected open MWRs found them to be not safety significant and not to affect the proper operation and safety function of the charging and HHSI systems.
Preventive Maintenance The team reviewed selected PM procedures for consistency with manufacturer recommendations and indust 7 practices. The review was focused on equipment associated with the charging and high head safety injection systems. The team also observed ongoing preventive maintenance to evaluate the adequacy of the procedure implementation. They found the procedures to be generally acceptable and the PM activities to be conducted in accordance with approved procedure.
Discussions with system engineering personnel determined that they were in the process of developing a PM optimization program. The goal was to optimize scheduling of PMs to decrease system unavailability. The team was not able to evaluate the effectiveness of this program but viewed it as a good initiative to improve operation of the plant.
Medium Voltaae Dreakers Maintenance Condition Report (CR) No. 972200, dated November 12,1997, stated that, when
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Operations tried to start the Unit 1 "C" River Water pump from the "DF bus, the pump failed to start due to a stuck circuit breaker trip latch. An identical failure had occurred earlier, in July 1996, with a safety-related breaker in a nonsafety-related application. The licensee's review of this issue determined that the failure was due to hardened gr9ase i
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and that the failed breakers, like the remainder of the Unit 1 medium voltage circuit breakers, had not undergone refurbishment since their manufacture, in 1971. In addit!on to normal preventive maintenance every three years, the manufacturer, Asea Brown Boveri, recommends complete breaker overhaul every ten years.
As a result of the failures, the licensee initiated refurbishment of all Unit 1 medium voltage breakers in both safety and nonsafety-related applications. At the time of the inspection, all but two breakers had been refurbished. The other two breakers, which -
supplied the "A" recirculation spray pump and the "B" auxiliary feedwater pump, were scheduled for refurbishment by the end of 1998. The team discussed the licensee's confidence regarding the ability of these and other breakers to operate on demand, prior ,
to their refurbishment. The licensee indicated that the breakers had undergone recent PM testing and that grease had been applied to vulnerable areas of the trip latch mechanism.-
Regarding the Unit 2 circuit breakers, also manufactured by Asea Brown Boveri, the licensee stated that they had been refurbished approximately 11 years ago, immediately prior to the unit commercial operation. The team discussed the licensee's current plans for refurbishment of these breakers. None had been made prior to the inspection, but the responsible system engineer indicated good experience with these breakers and that an evaluation would be made following refurbishment of the Unit 1 breakers.
Discussions with the licensee regarding normal PM activities determined that$ in the past the breakers had been incorrectly tested using a 100 Vdc control source. The PM procedure for all medium voltage breakers had been revised to use 70 Vdc for tripping and 85 Vdc for closing, reflecting the minimum design voltage requirements of the trip
' and close coils. These new values envelop the minimum voltage at the coils, as stated in the current revisions of the voltage drop calculations (see also section E1.2).
Low Voltaae Breakers Maintenance On March 28,1998, during the performance of a loss of offsite power (LOOP)/ loss of coolant accident (LOCA) test, a Unit 2,480 Vac motor control center supply circuit breaker failed to trip, as required by its control logic. The same breaker had failed previously, during an April 1995 test. Additional breaker failures were experienced, in similar circumstances, in October 1996 and in April 1998.
The licensee's subsequent review of the most recent failure found that the breaker would not trip until the control voltage had been raised to above 115 Vdc (normal testing was being conducted at 100Vde). In comparison, the calculated voltage at the trip coil for the breaker in question, under limiting conditions, is 113.8Vdc. The breaker is designed to trip at 70 Vdc. Based on their evaluation, the licensee attributed the failure to
" aged / inadequate lubricants in the operating mechanism which causes the force needed to move the trip bar to increase to the point that the breakers do not trip at reduced voltage [100Vdc]." The Maintenance Rule (a) (1) Disposition Review form that was issued to address this last failure also stated that the reduced voltage test failure "was not unexpected as the breakers are 20 years old and have not been overhauled."
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Originally, the licensee addressed only the failed breaker. Subsequently, they decided to test additional breakers of the same type and found that the majority of the breakers .i tested failed to meet their acceptance criteria of tripping at 100Vdc. These additional l failures resulted in the licensee expanding the test and lubrication to all safety-related breakers of the same type and to initiate a breaker overhauling program. In addition, 1
- they revised their testing procedure to test breakers tripping at 85Vdc. In comparison, the trip coil calculated voltage for all safety-related 480V air circuit breakers ranges from 97.15 to 112.56Vdc.
Discussions with licensee engineering personnel indicated that periodic testing of the 480V circuit breakers did not include a closing test, apparently because of difficulties in transferring the circuit breakers from their mounting location to the plant test facility. The licensee indicated that test sets had been purchased for mounting at the switchgear location and that installation was pending preparation of appropriate design changes.
Because the circuit breaker testing identified one failed trip coil and sluggishness in the movement of mechanical components associated with some other ones, the licensee began to replace all breaker trip coils. Originally the licensee believed that the failed trip coil was due to aging of the coil bobbin, but a vertical cut of the coil, during the inspection, revealed that overheating, probably due to a stuck trip bar, had caused a swelling of the bobbin below the iron core. The licensee also found that the sluggishness observed in certain coil assemblies was probably due to manufacturing tolerances which did not prevent the coil from operating within the design limits.
_ Unit 1,480V safety-related circuit breakers were not affected by the Unit 2 failures because they were overhauled between 1990 and 1991. As the Unit 2 breakers, the Unit 1 breakers have a 10-year refurbishment cycle requirement.
c. Conclusion In the area of Corrective Maintenance, the current backlog of open Unit 2 Maintenance
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Work Requests for the charging and high head safety injection (HHSI) systems was significant. However, a sampling of open Maintenance Work Requests identified no system operability concerns. The PM procedures related to the Charging and HHSl systems were generally acceptable and the PM activities consistent with approved procedures.
Engineering failed to recognize the need for circuit breaker refurbishment and did not take action to address this need until the manufacturer recommended refurbishment periods had expired by several years and breaker failures to actuate as expected had begun to occur. Also, testing of some 480V and 4160V air circuit breakers did not reflect the minimum calculated voltage for those breakers. As a result of the failures, they conducted thorough evaluations, took acceptable actions to reasonably assure the operability of the breakers, and revised the applicable test procedures to envelope calculated voltages at the breaker operating coils. This licensee-identified and corrected violation of 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, is being treated as a Non-Cited Violation, Consistent with Section Vll.B.1 of the NRC Enforcement Policy.
(NCV 50-334; 412/98-09 02)
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E2.2 Licensee Event Reports and Ooeratina Exoerience a. Inspection Scope (37550)
The inspector reviewed Licensee Event Reports (LERs), operating experience reports, and the System Engineering status reports for the charging and HHS1 systems.
b. Observations & Findinas Two issues affecting system performance were resolved during the 1998 extended maintenance outage: 1) binding of Atwood & Morrill check valves due to a material incompatibility, and 2) gas binding of charging pump suctions which was corrected by modification to the recirculation line orifice size. The team's evaluation of actions to address these issues found them acceptable. They observed, however, that satisfactory resolution of these deficiencies that adversely affected the proper performance of the equipment involved, did not occur for several years.
The June 1998 the System Engineering status reports for safety significant systems, including the charging and HHSI systems, contained useful performance indicators related to these systems and components. No negative trends were observed in these reports.
c. Conclusion Two significant issues affecting the charging and HHSI systems performance, i.e., the binding of Atwood & Morrill check valves, due to material incompatibility, and the gas binding of charging pump suctions, were resolved during the recent extended maintenance outage. However, the satisfactory resolution of these issues did not occur for several years after recognition of the problem.
E2.3 Corrective Action Proaram a. Inspection Scope (40500)
The team reviewed procedure NPDAP 5.6, " Processing of Condition Reports," and selected HHSI system-related Condition Reports (CRs), initiated in 1997 and 1998, to evaluate the process goveming the resolution of identified adverse plant cond tions.
b. Observations and Findinas Procedure NPDAP 5.6, " Processing of Condition Reports, " describes the licensee's means for addressing conditions adverse to quality identified in the plant equipment and processes. It includes the instructions for identification and resolution of the problem, and for category (significance level) and cause code assignments. The category assignments determine the extent and schedule of review as well as the level of management involvement in problem resolution. Cause codes facilitate the identification of root causes and of recommended actions to prevent recurrence.
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The team found the procedure to be well written and to provide sufficient direction and tools for the proper administration of the corrective action program. The team also observed some implementation weaknesses.' They found that, in some cases, the category level assigned was lower than expected and that the cause codes dealt primarily with the symptoms rather than the cause.
Examples of an improperly selected category include CRs 971423 and 971452 regarding unexpected radiation monitoring alarms caused during the August 1997 filling and venting of "A" demineralizer and subsequent elevated doses identified in the degasifier room. These two CRs were assigned a Category 4 level, i.e., a category reserved for
" minor" conditions which have low nuclear safety, regulatory, operability, or power production impact and for which the actions taken and documented are sufficient to i
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resolve the condition. Category 4 was also assigned to the CR documenting the failure of the Unit 1,4160V circuit breakers. The team considered none of the above examples to be " minor." Also, in the first two CRs the corrective actions to prevent recurrence had yet to be identified, and in the second example corrective actions were still ongoing. 1
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Despite the category assignment, the team's review found that responsible engineers I were fully fainiliar with the above issues and they were actively pursuing the actions to be taken for their proper resolution. The team also noted that, because root cause analyses had not been formally developed, engineers tended to be more conservative in the corrective actions, as in the case of the 480V circuit breaker trip coils which were replaced, although subsequent evaluation indicated acceptable performance. Lastly, the team determined that licensee management was aware of the corrective action program weaknesses and had already taken actions to address them. Such actions included, an original screening by cognizant personnel of low category CRs; a discussion of more important CRs at the moming meeting attended by management personnel from all plant functions; a detailed review of the planned corrective actions by the Corrective Action Review Board; and formal training of responsible engineering and management personnel in engineering fundamentals and root cause analysis techniques.
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c. Conclusions The procedure for processing condition reports was well written and provided sufficient direction and tools for the proper administration of the corrective action program.
However, the assignment of significance levels (categories) and cause codes to the -
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reports was not always correct, the first being sometimes lower than expected and the latter dealing primarily with the symptoms rather than the_cause of the condition.
Licensee management was aware of the program weaknesses and had already taken actions to address them through increased oversight and training of responsible engineering and management personnel in engineering fundamentals and root cause analysis techniques.
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E2.4 Corrective Action Review Board (CARB)
a. Insoection Scope (40500)
The team attended a Beaver Valley Corrective Action Review Board (CARB) meeting and reviewed the Condition Reports addressed in the meeting to assess the effectiveness of the board in their CR corrective action verification process.
b. Observations & Findinos The CRs reviewed at the CARB meetings are usually distributed to the board members at the conclusion of the previous meeting. This is to facilitate their independent review and screening beforehand of those CRs for which the corrective actions are deemed appropriate and, hence, not worthy of discussion at the meeting. In the meetings, in accordance with their procedure, the CARB members first set aside the CRs for which all i members agreed the corrective actions were acceptable. Then they address the l concerns they have identified with the CR-stated resolution.
The team observed the procedures used for the meeting and the discussions among the various CARB members. The team found good synergism among board members and that they gave careful consideration to the Condition Reports and to the closeout process. Of the CRs reviewed, some were rejected due to poor problem description, incomplete response, or inadequate corrective action, and some tabled pending clarifications by the responsible staff member. The team also noted that the CARB's review provided positive insights in the problem identification, cause analysis, and corrective action process.
c. Conclusion The Corrective Action Review Board review of Condition Reports (CRs) provided positive insights in the problem identification, cause analysis, and corrective action process.
Good synergism existed among the board members in their consideration of the CRs and the identified corrective actions.
E3 Engineering Procedures and Documentation E3.1 System Operatina Procedures i
a. Inspection Scope (93809) !
The team reviewed selected operating and surveillance procedures for the charging and high head safety injection (HHSI) systems. In addition, the team verified valve configurations and witnessed ongoing system surveillance.
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b.' Observations & Findinas The team's review of selected normal and emergency operating procedures, including those for pump venting and for the operations surveillance of these systems, found them to be acceptable. The team also found that system valve lineups and plant configuration were consistent with applicable drawings, the updated final safety analysis report (UFSAR) and the technical specifications (TS). .
The team observed the calibration and performance of the periodic ultrasonic test (UT) of the system piping to identify potential gas voids. They observed no abnormalities in the 4 calibration of the equipment and found that the UT test was being conducted in accordance with the test plan. The test itself confirmed that no gas voids were present at the high points of the Unit 2 charging pump /HHSI piping and that the installation of modified flow orifices in the pump discharge lines had been successful in reducing gas accumulation and, hence, pump degradation. The team's observation of ongoing monitoring of the service water (SW) flow to charging pump oil coolers determined that the performance data taken by the operators was extensive, the system engineer
. actively participated in the system surveillance, and that the data points were being maintained in a computer-based tracking system.
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c. Conclusion The review of selected operation procedures associated with the Unit 2 charging and high head safety injection systems, including those for venting and operations surveillance testing of the charging pump, identified no safety issues. Similarly, no negative issues were observed in the verification of applicable valve lineups against plant configuration.
E3.2 System Testina a. Insoection Scope (93809)
The team reviewed system Operating Surveillance Test Procedure 2OST-7.4 and the results of a recent test. For applicable system components, the team also reviewed the inservice test (IST) program, test results, and trending of the IST test results by the engineer.
b. Observations & Findinas The team reviewed Operating Surveillance Test Procedure 2OST-7.4 for the Unit 2 "A" centrifugal charging pump. The review included an evaluation of system instrumentation, controls, and plant conditions. The team also reviewed the results of a test performed on September 7,1998 and campared them to the required system parameters. The team found the test procedure to be comprehensive and properly completed. No anomalies were observed with the test results.
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The team's review of the inservice test program for applicable components in the charging /high head safety injection systems identified no area of concern and found it acceptable. Also, a review of selected test results and discussions with the responsible IST test engineer regarding trending of the results confirmed the adequacy of the program for the areas' reviewed. The team also determined that no high head safety injection system pumps or valves were currently in an alert status.
c. Conclusion The review of selected system test procedures and test results and discussions with responsible IST test engineers indicated that the testing of the charging and high head safety injection systems was acceptable. Procedures were comprehensive and properly implemented.
E7 Quality Assurance in Engineering Activities E7.1 Self-Assessment a. Insoection Scope (37550)
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The team reviewed the involvement of the Quality Assurance (QA) organization in plant activities, the effectiveness of the Operating Experience (OE) group in obtaining and processing industry operating experience, the progress of the 50.54f team in evaluating the accuracy of the UFSAR in describing plant systems, and the involvement of the System Engineering group to determine the status of plant systems.
b. Observations & Findinas The team found the QA organization to be actively involved in plant activities. The team also found the QA's plan and verification of technical specification testing requirements to be well executed. The QA top 10 list of plant focus issues was viewed as a strength.
Within the inspection scope, the Operating Experience Review Group was found to have an effective plan for reviewing incoming information from various industry sources, dispersing industry information to applicable plant units, and tracking resolution of applicable items. Also, the team identified no concerns in the licensee's 50.54f effort to reach conformance between the UFSAR and other design and licensing basis documents.
The System Engineering System Status Report dated June 1998 was a comprehensive summary of the status of selected Unit 1 and Unit 2 systems.
c. Conclusion The Quality Assurance (QA) organization was actively involved in plant activities and had developed a top 10 list of plant focus issues. The QA plan and verification of technical specification testing requirements was welllaid out. The review performed by QA, the
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Operating Experience Group, and Systems Engineering indicated good self-assessment efforts by the disciplines involved.
V. Manaaement Meetinas
'X1 . Exit Meeting Summary The team presented the inspection results to members of licensee management at the conc!usion of the inspection in a telephone conference, on December 17,1998. Subsequently, on February,4,1999, also via telephone, the NRC presented to the licensee the results of the additional office inspection conducted during the period uf January 4 - 6,1999. The licenseo acknowledged the findings presented during both meetings.
' The licensee did not indicate that any of the information presented at the exit was proprietary.
PARTIAL LIST OF PERSONS CONTACTED Beaver Valley M. Ackerman Manager- Safety & Licensing R.' Bologna Supervisor- NED J. Cross President Generation Group C. Custer - Director- Performance Engineering B. Davis - Director, System Engineering P. Dearbom Supervisor- NED P. Eisenmann - System Engineer K. Frederick Supervisor- Nuclear Analysis K. Halliday Director - Plant Support Engineering R. Hart Sr. Licensing Supervisor R. Hruby Director- Design Basis Engineer !
. S. Jain Sr. Vice President - Nuclear Services W. Kline - Manager- Nuclear Engineering J. Macdonald Manager- SPED ]
A. Mizia . Supervisor- QSU K. Ostrowski .Vice President- Ops / Plant Manager
. M. Pearson Manager- Quality Services A. Ryan Sr. Engineer (Acting CRPA)
G. Schildt Supervisor- System Engineering P.Sena OSC Chairman - Ops SRO Unit 2 B. Sepelak Sr. Engineer- Licensing NBC D. Kem, Sr. Resident inspector - Beaver Valley D. Lew, Chief, Electrical Engineering Branch, DRS j
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'18 INSPECTION PROCEDURES USED IP 37001 10 CFR 50.59 Safety Evaluation Program IP 37550 . Engineering IP 40500 Effectiveness of Licensee Controls in identifying, Resolving, and Preventing Problems
. lP 93809: ' Safety System Engineering inspection ITEMS OPENED, CLOSED AND DISCUSSED Opened (
50-412/98-09-01 VIO Design Control- Failure to ensure that the breaker design requirements were properly applied and verified.
50-334;412/98-09-02 NCV Inadequate testing of 480V and 4160V air circuit breakers LIST OF ACRONYMS USED AC or ac Altemating Current ASME American Society of Mechanical Engineers BV .
Beaver Valley CARB . Corrective Action Review Board j
.CFR Code of Federal Regulations- 3 CR Condition Report DBD Design Basis Document DC or dc Direct Current DCP Design Change Package
'DLC. Duquesne Light Company DRS Division of Reactor Safety EA' Enforcement Action EDG Emergency Diesel Generator GL . Generic Letter _
HHSI- High Head Safety injection ICV Individual Cell Voltage IEEE Institute of Electrical and Electronic Engineers IST Inservice Test LCO Limiting Condition of Operation LER Licensee Event Report LOCA Loss of Coolant Accident LOOP Loss of Offsite Power MRT Management Review Team MWR Maintenance Work Request NCV Non-Cited Violation NRC Nuclear Regulatory Commission NRR. Office of Nuclear Reactor Regulation
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OE Operating Experience OST Operating Surveillance Test PCP Process Control Program PM Preventive Maintenance PRA Probability Risk Assessment QA Quality Assurance RCS Reactor Coolant System SSEl Safety System Engineering inspection SW Service Water TER, Temporary Evaluation Report TM . Temporary Modification TS Technical Specification >
UT Ultrasonic Test UFSAR- Updated Final Safety Analysis Report I V Volts VDC or Vdc Volts Direct Current
'VOND. Valve Operator Number Drawing .
W. Westinghouse-1
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