IR 05000315/1997024
| ML17334A644 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 01/23/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17334A642 | List: |
| References | |
| 50-315-97-24, 50-316-97-24, NUDOCS 9802040082 | |
| Download: ML17334A644 (35) | |
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U.S. NUCLEAR REGULATORYCOMMISSION
REGION III
Docket No.
50-.315,50-316
'I License No,.
50-315/97024(DRP); 50-316/97024(DRP)
Licensee:
Indiana and Michigan Power 500 Circle Drive Buchanan, Ml 49107-1395 Facility:
'onald C. Cook Nuclear Generating Plant Location:
1 Cook Place Bridgman, Ml 49106 Dates:
November 8, 1997, through December 27, 1997 Inspectors:
Approved by:
B. L. Bartlett, Senior Resident Inspector...
B. J. Fuller, Resident Inspector J. D. Maynen, Resident Inspector Bruce L. Burgess, Chief Reactor Projects Branch 6 9802040082 980i23 PDR ADGCK 050003i5
EXECUTIVESUMMARY D. C. Cook Units 1 and 2 NRC Inspection Report No. 50-315/97024(DRP); 50-316/97024(DRP)
This inspection included aspects of licensee operations, maintenance, engineering, and plant support, The report covers a seven-week period of resident inspection and includes the followup to issues identified during previous inspection reports.
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The inspectors identified a violation in which the licensee had been removing control room annunciators from service without maintaining records which contained a written safety evaluation as required by 10 CFR 50.59 (Section 03.1).
Maintenance Licensee personnel identified a blocked hydrogen skimmer connection to a steam generator enclosure.
The blockage of this line, coupled with failure of the opposite train skimmer, could have resulted in an excessive buildup of hydrogen gas in the steam generator enclosure following a postulated loss of coolant accident.
This issue is considered an unresolved item pending the results of testing the individual flow connections from each containment enclosure (Section M1.2).
During periodic maintenance on the Unit 2 upper containment airlock, licensee mechanics found that the "0" ring seal material installed on the inner bulkhead interlock shaft was Teflon packing rather than the specified EPDM elastomer.
This is considered an unresolved item pending the results of the root cause assessment and a determination of the safety significance of the use of Teflon seals (Section M1.3).
The licensee's efforts to modify the Unit 2 AB diesel generator (D/G) reflected a weakness in design control in that multiple changes were made to engine components without a thorough understanding of the interrelations of proposed modifications. The engine timing change, performed to reduce cylinder pressure, in conjunction with the fuel-line changes, resulted in several other engine parameter changes which were not anticipated by the licensee.
The troubleshooting and analyses required to correct the engine parameters resulted in a significant delay in the licensee's restoration of the 2 AB D/G to service (Section M2.3).
A non-cited violation was issued when licensee personnel identified that non-safety-related parts were used during maintenance activities on the Unit 2 AB diesel generator.
The licensee looked for other instances where non-safety-related parts could have been used and identified one other example (Section 4.1).
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The inspectors identified a violation in which the licensee failed to treat the manual backwashing of the ESW strainers in accordance with,quality standards commensurate with the importance of the safety functions to be performed.
The licensee committed to complete the corrective actions necessary prior to placing either unit in Mode 4, Hot Shutdown (Section.E1:1).
Plant Su ort No discrepancies were noted.
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ea Re ort Details Summa of Plant Status y
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Unit 1 remained in Mode 5, Cold Shutdown, during this inspection period. The unplanned outage was in response to NRC and licensee concerns with the operability of the containment recirculation sump and other engineering issues.
Unit 2 was in Mode 6, Refueling,. at the beginning of this inspection period.
On December 5, 1997, the licensee entered Mode 5, Cold Shutdown.
The Unit remained in Mode 5 throughout the remainder of the inspection period.'l
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Conduct of Operations 01.1 General Comments 71707 60710 and 86700 Using the referenced inspection procedures, the inspectors conducted frequent reviews
'f ongoing plant operations.
Maintaining both Units in Mode 5 for a prolonged period and the recovery from the Unit,2 refueling outage were properly handled by the operators.
Specific events and noteworthy observations are detailed in the sections below.
Of special note was that on December 18, 1997, an Operations Shift Manager (SM)
challenged the conservatism of an engineering calculation that was done. in support of an operability decision.
The SM was concerned that the calculation did not properly account for some essential service water (ESW) flowand that some ESW flow could be diverted from safety-related components during a design basis event. The calculation was subsequently reviewed by engineering to ensure that the concern was appropriately resolved.
The SM's challenge of the calculation was appropriate and timely.
Operational Status of Facilities and Equipment 02.1 En ineered Safet Feature S stem Walkdowns Both Units In addition to routine plant inspections, the inspectors used Inspection Procedure 71707 to walk down selected portions of the residual heat removal, condensate tank, refueling water storage tank, and containment recirculation sump systems for both units.
No operability concerns were identifie Operations Procedures and Documentation
'3.1 Removin Control Room Annunciators From Service Without a Safet Evaluation Both
~Units C
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~ a Ins ection Sco e 71707 and 37001
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During a routine tour of the control rooms, the inspectors questioned the,licensee's practice of removing annunciators from service.
The inspectors performed routine followup and reviewed the following documents:
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Operations Head Instruction (OHI)
-. 2211, Revision 20, "Maintenance of Operations-De'partmeht Logs" II C
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02-Operations Head Procedure (OHP) 4024;221, Revision 4, "Annunciator Panel
... Number 221 - Generator"
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02-OHP 4024.222, Revision 4, "Annunciator Panel ¹222 Response:
Plant Service"
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UFSAR Sections 7.5, 10.3
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Condition Report (CR) 97-3314, Operations procedure does not require that a 10 CFR 50.59 review be performed prior to blocking an alarm.
Observations and Findin s On November 16, 1997, during a routine tour of the control rooms, the inspectors questioned the licensee's method of removing control room annunciators from service.
The licensee's procedures allowed the blocking [by physically or electronically preventing operation] of annunciators without a safety review as required by 10 CFR 50.59,
"Changes, tests, and experiments."
The licensee's existing program, described in Procedure OHI-2211, stated that a technical review must be performed prior to the removal of an alarm from service.
However, the technical review, performed by a Senior Reactor Operator, focused on TS requirements and required compensatory actions.
The technical review was not intended to meet the requirements of 10 CFR 50.59.
The inspectors reviewed the blocked alarm log and determined that the following annunciators had been blocked since at least July 5, 1996:
Unit 1 Annunciator Panel ¹121, Drop 17, "Stator Winding Rec[order] High" Unit 2 Annunciator Panel ¹222, Drop 81, "Ice Condenser Recorded Ice Temp[erature] Hi or Lo" Unit 2 Annunciator Panel ¹221, Drop 16, "Stator Winding Rec[order] High"
The function of these annunciators was described in the Updated Final Safety Analysis Report Chapters 7.5 and 10.3. Allthree annunciators provided an alarm in the control room ifthe temperature setpoints were exceeded; however, none of them provided an equipment control function or required immediate, operator, action. The actual safety consequences of blocking the annunciators was minor, however, the regulatory significance of blocking safety-related annunciators without performing a proper safety review per 10 CFR 50.59 was significant.
II 10 CFR 50.59, "Changes, tests and experiments," required, in part, that the licensee shall maintain records of changes in the facilityas described in the safety analysis report.
These records must include a written safety evaluation which provides the basis for the determination that the change does not involve, an unreviewed safety question.
On December 15, 1997, an NRC 10 CFR 50.59 panel reviewed-the circumstances surrounding the removal of annunciators from service. without maintaining a written safety
'evaluation.
The failure to maintain records which contained a written safety evaluation for three blocked control room annunciators which constituted a change to the facilityas described in'the safety analysis report is considered a violation of 10.CFR 50.59 (50-315/97024-01a(DRP));
(50-316/97024-01b,c(DRP)).
Conclusions The inspectors identified a violation in which the licensee had been removing control room annunciators from service without maintaining records which contained a written safety evaluation as required by 10 CFR'50.59.
M1 Conduct of Maintenance M1.1 General Comments II. Maintenance a.
Ins ection Sco e 62707and 61726 Portions of the-following maintenance job orders, action requests, and surveillance activities were observed or reviewed by the inspectors:
A150778, Inspect and repair the Unit 2 main and auxiliary transformers isophase transition box A0149089, Repair of insulation and coatings in Unit 2 containment A0153671, Unit 1 CD diesel generator fuel oil leak at base of injector
- 02-OHP 4030. Surveillance Test Procedure (STP).027AB, Revision 10,
"AB Diesel Generator Operability Test (Train B)"
12 Engineering Head Procedure (EHP) 4050.Fuel Handling Procedure (FHP).301, Revision, "Core Reload"
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Job Order (JO) C29866, Replace 2-CD battery bank
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12 Instrumentation and Controls Head Procedure (IHP) 5021.
Electrical
'Maintenance Procedure (EMP).006, Revision 2, "Battery Cell Replacement"
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- 02 OHP 4030.STP.038, Revision 5, "Leak Rate Test of Liquid Systems"
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Job Order R72312, 2 AB D/G, perform 18 month diesel surveillance EH Observations and Findin s I
W The inspectors concluded that most of the observed work activities were performed in a quality manner with procedures present and in use; however, some maintenance activities continued to challenge the licensee.
Specifically, problems were identified concerning two previous maintenance activities: "a plugged hydrogen skimmer line (discussed in Section M1.2) and Teflon packing rings in Unit 2 upper containment airlock (discussed in Section M1.3). Two maintenance problems concerning the 2 AB emergency diesel generator were also identified: weak design control regarding engine modifications (discussed in Section 2.1) and improper fasteners used to secure engine components (discussed in Section M4.1).
Inadvertentl Plu ed H dro en Skimmer Suction Line Unit 2 Ins ection Sco e 62707 On November 26, 1997, licensee maintenance personnel identified a blockage of the Steam Generator (S/G) ¹3 enclosure Train B hydrogen skimmer suction piping. The inspectors performed walkdowns of the hydrogen skimmer system in Unit 2 containment and observed the licensee's investigation, short-term corrective actions, and long-term corrective actions.
Licensee procedures and documentation reviewed included:
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- 12THP Technical Head Procedure (THP) 6040 PER. 098
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JO C006665, Replace heaters in upper compartment quadrant 3 ventilation unit Observations and Findin s Portions of safety-related piping for the hydrogen skimmers had been removed to facilitate the replacement of non-safety-related heaters inside Unit 2 upper containment.
During the foreign material exclusion inspection, licensee maintenance personnel identified blockage of the Steam Generator (S/G) ¹3 enclosure Train B hydrogen skimmer suction piping to the air recirculation/hydrogen skimmer fan, 2-HV-CEQ-1. The discovery of material blocking the skimmer suction piping was an indication that the licensee's efforts to improve identification of foreign material was beginning to produce results.
The hydrogen skimmer system functions to minimize accumulated hydrogen in the upper portions of the S/G and pressurizer enclosures following a loss of coolant accident.
Two subsystems of hydrogen skimmer are available in containment.
Each hydrogen skimmer subsystem has connections to each S/G enclosure, so that each pair of S/Gs has a total of four suction connections.
Each S/G hydrogen skimmer line was required to pass a
nominal 250 standard cubic feet per minute (SCFM) of air flowwhen the associated hydrogen skimmer fan was in service.
The Updated Final Safety Analysis Report (UFSAR) stated that ifhydrogen skimmer flow were as low as 455 SCFM from a paired S/G enclosure, the hydrogen concentration would not exceed the 4 volume percent flammability limitinside the paired S/G enclosure.
Train A connections to the S/G ¹2 and S/G ¹3 enclosure were open and would have provided the required flow of at least 455 SCFM. However, assuming a single failure and the'loss of the Train A fan during a L'OCA, only'degraded Train B would have been available to meet the required flow.
The system engineer postulated that the hydrogen skimmer piping may have been blocked;during resto'ratio'n work from the Unit 2 steam generator replacement project (SGRP) in 1989. The concrete roof of each S/G enclosure had been removed to permit S/G repairs.
The area where the skimmer piping'penetrated the roof wa's not to be disturbed during the repair but was close to the chip back line specified for concrete
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replacement.
-When the forms were built prior to the concrete pour for the steam generator enclosure, the penetration may have been inadvertently covered.
A contributing cause for the licensee's failure to identify the blocked hydrogen skimmer piping was the lack of testing of the skimmer system.
No test of the hydrogen skimmer
'ystem had been scheduled because the suction lines were in an area that was not part of the SGRP.
Flow balancing of the skimmer system in Unit 2 was last performed in October 1985 using test Procedure **12THP 6040 PER.098.
The as-left flowrates for 17 of the 19 test points were not within the acceptable flow as specified on the Final AirFlow Tabulation data sheet.
Although all 17 points were left higher than the maximum allowed by the procedure, they were still outside the acceptance criteria.
No disposition existed for the flows that were outside acceptable limits. The 1985 as-left combined flows for the S/G ¹2 and S/G ¹3 enclosure were greater than the nominal 455 SCFM stated in the UFSAR. Due to physical constraints in the S/G ¹2 and S/G ¹3 enclosure, individual skimmer line flowtests were not performed.
The licensee's failure to have a valid surveillance test to verifythat individual line flow rates for this system met the UFSAR stated values is considered a significant weakness.
Pending the results of the flowtesting for the individual flow connections in each steam generator enclosure, this willremain an Unresolved Item (50-316/97024-03(DRP)).
Licensee personnel removed the concrete grout which was plugging the S/G ¹3 enclosure connection and performed hydrogen skimmer system flowverifications.
Based on the results of the flowverifications, licensee personnel determined that the remaining hydrogen skimmer connections were free from blockage.
The inspectors subsequently performed an independent verification of the skimmer connections and agreed with the licensee's determination.
Conclusions Licensee personnel identified a blocked hydrogen skimmer connection to a steam generator enclosure.
The blockage of this line coupled with failure of the opposite train skimmer could have resulted in an excessive buildup of hydrogen gas in the steam
generator enclosure following a postulated loss of coolant accident.
This issue was determined to be an unresolved item pending the results of testing the individual flow connections from each containment enclosure.
Teflon Packin Rin s in U er Containment Airlock Unit 2 Ins ection Sco e 62707 On December 7, 1997, maintenance personnel discovered Teflon packing installed in the Unit 2 upper containment airlock instead of the specified EPDM elastomer.
The inspectorsinterviewed the system engineer and observed the licensee's investigation, including the'development of both short-term and long-term corrective actions.
Observations and Findin s
'uring periodic maintenance on the Unit 2 upper cohtainment airlock, licensee mechanics found that the "0" ring seal material installed on the inner bulkhead interlock shaft was Teflon packing rather than the specified EPDM elastomer.
The "0" ring seals were designed to prevent a leakage path from containment into the airlock compartment and from the airlock compartment into the auxiliary building. The inspectors were concerned because Teflon willdegrade significantly in high radiation fields, such as would exist inside containment following a postulated loss of coolant accident, and deterioration of the seal rings in the airlock could result in a leakage path from the containment to the airlock compartment.
Periodic maintenance on the airlock is done on a five-year nominal cycle fo look forwear in the "0" ring seals and.other parts.
The periodic maintenance had been last performed in 1992 for this airlock. The licensee stated that because the wording in the job order was limited to a statement requiring only the replacement of EPDM seals, the mechanics performing the work may have interpreted the instructions to mean that the Teflon seals did not need to be replaced.
The original specifications for the airlock did not specify the "0" ring seal material. The airlock as supplied by the vendor was flitted with Teflon seals.
A major refurbishment program for the airlocks was conducted over a period of three years commencing in 1988. As a result of NRC and industry concerns with the lifespan of sealing materials, natural rubber seals were initiallyreplaced by Grafoil type seals.
Subsequently, due to difficulties with the installation of the Grafoil seals, a switch to the EPDM seals was initiated. The job orders directed changing the seals on the handwheel hub and interlock mechanism on the interlock door to EPDM seals.
The licensee stated that during performance of the work, it appeared that only the seals on the hubs were changed.
The licensee further speculated that the work instructions were not explicit in calling out part numbers for the interlock mechanism and that the mechanics may have misinterpreted the instructions as only pertaining to the mechanism on the door itself.
The licensee's assessment of the root causes and of the safety significance was continuing at the end of the inspection period.
Pending the results of the root cause assessment and a determination of the safety significance, this will remain an Unresolved Item 50-316/97024-04(DRP)).
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Conclusions During periodic maintenance on the Unit 2 upper containment airlock, licensee mechanics found that the "0" ring seal material installed on the inner bulkhead interlock shaft was Teflon packing rather than the specified EPDM elastomer.
This was considered an unresolved item pending the results of the root cause assessment and a determination of the safety significance of the use of Tefion seals.
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Maintenance and Material Condition of Facilities and Equipment M2.1 Weak Desi n Control for'Modifications on the AB D/G Unit 2 r
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Ins ection Sco e 62707
i During the 18-month surveillance on the Unit 2 AB diesel generator (2 AB D/G),
modifications were carne'd'out 1o chan'ge the high pressure fuel lines and engine timing.
Following these modifications, unanticipated effects on D/G performance were experienced. The inspectors followed the licensee's modification and testing efforts and reviewed the following documents:
UFSAR Section 8.4, "Emergency Power System" Component Evaluation No. CE-96-0293, Replace emergency diesel generator fuel injection tubing CR 97-3110, On November 4, 1997, while operating the 2 AB D/G for a maintenance run, the high pressure fuel line at ¹1 front bank failed.
CR 97-3157, On November 6, 1997, during the. operation of the 2 AB D/G, the new ¹4 rear bank stainless steel high pressure fuel line lifted out of the compression nut and ferrule.
CR 97-3175, On November 7, 1997, during inspections performed on 2AB D/G fuel lines, it was determined that the line ends and ferruies were not being set properly.
CR 97-3176, On November 8, 1997, 2 A/8 D/G ¹3 rear bank fuel injection line mechanical connection failed at the injector end.
CR 97-3264, On November 12, 1997, after 2 AB D/G was started and loaded for the 24-hour maintenance run, the air chest high pressure alarm unexpectedly came in.
CR 97-3263, On November 13, 1997, 2 AB D/G blew a fuel line off¹4 rear injector.
CR 97-3277, On November 15, 1997, 2 AB D/G ¹3 front high pressure fuel oil line developed a pin hole leak while running at full load.
Due to high peak cylinder pressure on the 2 AB D/G, the licensee evaluated engine performance enhancements which might reduce the peak cylinder pressure.
The two selected enhancements involved changing the high pressure fuel lines and retarding the engine timing by several degrees.
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I Fuel Line Problems The component evaluation for replacing diesel generator fuel injection tubing (CE-96-0293) concluded that stainless steel. lines of a larger inner diameter would be acceptable replacements, for the installed carbon steel fuel injection lines. The licensee added the fuel injection line replacement to the refueling outage maintenance on the 2 AB D/G after.two fuel line through wall failures occurred in October and November 1997. A new installation procedure was developed which provided more specific guidance for installing the fuel line connections and avoiding reliance on the "skill of the craft."'he installation of stainless steel fuel injection lines coupled with the use of new compression fittings and proceduralized assembly instructions initiallyresulted in difficulties in obtaining satisfactory connections for the fuel lines. Problems with the installation and testing of the new fuel lines were documented in the condition reports listed above.
The licensee sent several fuel lines, ferrule fittings, and.connecting nuts to an offsite laboratory for testing to determine the most probable failure mechanism.
After reviewing fuel line test results and consulting with the fuel line vendor, the licensee's engineering staff found that the fuel line connection problems could be attributed, in part, to the following:
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The connecting nuts provided with the new stainless steel high pressure fuel lines were received from the vendor incorrectly machined.
These nuts may have damaged the ferrule fittings, resulting in connection failure at normal operating pressure.
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The new installation procedure required using the connection nut torque prescribed by the D/G vendor technical manual instead of ferrule fitting compression to determine connection tightness.
The 2 AB D/G 18-month maintenance was the first time when this new installation procedure was used.
To resolve the connection problems, the incorrectly machined connecting nuts were replaced with properly machined connecting nuts.
Concurrently, a high pressure fuel line installation procedure based on ferrule fitting compression rather than connecting nut torque was developed with the fuel line vendor's concurrence.
Following these corrective actions, the licensee did not identify any other fuel line connection problems.
The inspectors concluded that the licensee's troubleshooting efforts, including consultation with the fuel line vendor and offsite testing of several connections, were aggressive and thorough.
En ine Timin Chan es As a part of the 18-month maintenance, the 2 AB D/G timing was retarded by three degrees to reduce peak cylinder pressure.
-.The inspectors noted that, although the timing change did have the desired result of reducing cylinder pressures, many other engine parameters also changed.
At D/G full load, the air chest pressure alarm annunciated, causing the operators to reduce load and subsequently terminate the reliability run.- The licensee's engineering staff also noted that the new stainless steel high pressure fuel lines had a larger inner diameter than the carbon steel lines which were replaced.
The effect of the larger diameter was similar to retarding the engine timing by 3 percent.
During several attempts at completing a 24-hour reliability run on the 2 AB D/G, the licensee identified several unexpected engine parameter changes:
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Airchest pressure was higher than, expected.,
~ I' 'he dynamic loading characteristics of the. diesel engine were slightly changed.
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The fuel oil consumption rate increased.
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Fuel rack maximum travel was reduced.
The licensee consulted the D/G vendor concerning the engine parameter changes.
With the vendor's concurrence, the air chest pressure alarm and trip set-points were raised, and the test was repeated.
Two additional set point changes were required before the 2 AB D/G could be run at full load without receiving an air chest high pressure alarm.
In addition, the installed air chest pressure gauge was replaced with a gauge with a higher range to accommodate the higher alarm set point.
Additionally, the licensee's engineering staff evaluated the dynamic load characteristics, limited fuel rack travel, and increased fuel consumption of the 2 AB D/G. The licensee's engineering staff concluded that, even with the limited fuel rack travel and increased fuel consumption, the 2 AB D/G would still be able to properly sequence on safety-related loads following a design basis accident and run at full load for one week with the minimum amount of fuel required by TSs in the fuel oil tank. The inspectors reviewed the licensee's evaluation of the 2 AB D/G and had no additional concerns.
Conclusions The licensee's efforts to modify the Unit 2 AB diesel generator (D/G) reflected a weakness in design control in that multiple changes were made to engine components without a thorough understanding of the interrelations of proposed modifications. The engine timing change, performed to reduce cylinder pressure, in conjunction with the fuel line changes, resulted in several other engine parameter changes which were not anticipated by the licensee.
The troubleshooting and analyses required to correct the engine parameters resulted in a significant delay in the licensee's restoration of the 2 AB D/G to service.
0 en Ins ection Followu Item 50-316/97018-05:
2ABdieselgeneratorpoormaterial condition. The 2 AB D/G had been placed on an accelerated surveillance frequency following the second valid test failure in August 1997. Condition Report 97-2810 was
issued on October 14, 1997, to document the third functional failure of the 2 AB D/G over a two year period. This functional failure resulted in the licensee placing the 2AB D/G in maintenance rule category (a)(1).
In addition to moving the 2 AB D/G to maintenance rule category (a)(1), the licensee also elected to implement a material condition outage.
Alloutstanding maintenance work requests were evaluated; those that.did not involve a major tear down of the D/G were worked.. This resulted in many minor oil and water leaks being repaired.
This item willremain open until the. licensee has issued their corrective actions for the 2 AB D/G and the inspectors have had an opportunity to review the corrective actions.
F M2.3 0 en Unresolved Item 50-315/97018-06 50-316/97018-06:
Diesel Generator Exhaust Manifold Brackets'(Both Units). On October 19, 1997, while running the 2 AB D/G for an eight-hour surveillance test, the'flywheel end exhaust manifold bracket failed. The licensee speculated'that'missing jam nuts may have allowed the bracket bolt to come loose, resulting in a fatigue failure of the bracket; however, the minor modification package paperwork indicated that the jam nuts had been installed. The licensee began an investigation into the root cause of the bracket failure, but the investigation was not completed at the end of this, report period. This unresolved item remains open pending a review of the licensee's investigation into the root cause of the bracket failure.
M4 Maintenance Staff Knowledge and Performance M4.1 Non-Safe-related Ca screws and Nuts Used in a Safet -related A lication Unit 2 a.
Ins ection Sco e 62707 On December 2, 1997, the licensee identified that some of the capscrews used to hold the 2 AB D/G combustion air turbocharger air aftercoolers were drawn from stock spares rather than from safety-related stores.
The inspectors followed up on this finding. The following documents were reviewed:
- 12 Maintenance Head Procedure (MHP) 5021.032.015, Revision 2, "Emergency Diesel Engine Intake AirAftercooler Maintenance" JO R36576; Open, inspect, clean, and close 2 AB D/G north combustion affercooler JO R37665; Open, inspect, clean and close 2 AB D/G south combustion aftercooler CR 97-3461, Non-certified bolts installed on 2 AB D/G aftercoolers CR 97-3496, Non class 30 nuts installed on 2 AB D/G crankcase covers CR 97-3494, Potential adverse trend relative to control of contractors
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~Findin n
On December 2, 1997, a contract worker performing the 18-month maintenance work on the 2 CD D/G told a licensee supervisor that some of the capscrews used to replace. the 2 AB D/G intake air aftercoolers had been drawn from open stock spares rather than from safety-related stores.
The licensee inspected the capscrews and found that 32 of 84 capscrews were drawn from open stock spares.
The 2 AB D/G was declared inoperable, and the appropriate TS action statements were entered.
Several capscrews from the open stock spares were tested for material composition and strength;- The results of this testing and analysis indicated that the installed capscrews exceeded the 'American-Society for Testing and Materials (ASTM) A574 standard.', The licensee's>engineering staff also conducted an analysis'assuming worst-case ASTM A307 caps'crews were installed.'his analysis'howed that even iflower standard capscrew's were installed, the vertical restraint spring cans and the remaining correl:t capscrews would have prevented the aftercooler from coming loose during operation or a design basis earthq'uake.
Therefore, no operability question existed with the 2 AB D/G. The 2 AB D/G was declared operable, and the TS action statements were exited. The inspectors reviewed the testing and analysis results and had no additional concerns.
While performing followup on the capscrews, licensee personnel identified that non-certified nuts had also been installed to hold'crankcase covers in place on the 2 AB D/G.
The non-certified nuts had been installed by the same, contractor personnel who installed the non-safety-related capscrews.
The crankcase covers are designed to relieve internal crankcase pressure which would not challenge the structural integrity of the crankcase cover nuts and studs. The licensee determined that the use of non certifil.'d parts would have no operability impact.
The work on the aftercoolers was performed under job orders R36576 and R37665 which were marked as safety-related.
These Job Orders referred the workers to Procedure
- 12 MHP 5021.032.015 for instructions on how to perform the aftercooler maintenance and reinstallation.
This procedure specified that the capscrews meet the ASTM standard A574; however, no documentation existed which indicated that the open stock spare capscrews met this standard.
Title 10 CFR Part 50, Appendix B, Criterion Vill, required, in part, that measures shall be established for the identification and control of materials, parts, and components, including partially fabricated assemblies.
These identification and control measures shall be designed to prevent the use of incorrect or defective material, parts, and components.
The two examples of failure to utilize the required parts were a violation of 10 CFR Part 50, Appendix B, Criterion Vill,in that no measures were in place to prevent contractor personnel from using non-certified parts drawn from open stock spares in a safety-related application. This non-repetitive, licensee-identified and corrected violation is being treated as a Non-Cited Violation (NCV), consistent with Section VII.B.1 of the NRC Enforcement Policy (50-316/97024-05)
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Conclusions A non-cited violation was issued when licensee personnel identified that non-safety-related parts were used during maintenance activities on the Unit 2 AB diesel generator.
The licensee looked for other instances where non-safety-related parts could have been used and identified one other exampl M8 Miscellaneous Maintenance Issues M8.1 r
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CI Closed Violation 50-315/97004-02b:
Spiral wound gasket material in the reactor coolant system and the reactor vessel (Unit 1). On March 12, 1997, during Unit 1 core off-load, the licensee found spiral wound gasket material on the bottom of several fuel assemblies and the lower core plate. The source of this material was later determined to be from the spiral.wound gaskets on the-residual heat removal (RHR) heat exchanger outlet valves, 1-IRV-310 and 1-IRV-320. Additional material may also have remained in the reactor coolant system from an earlier failure of the spiral wound gasket on the RHR heat exchanger bypass valve, 1-IRV-311. The spiral wound gaskets on these three valves were replaced with compressed fiber gaskets, and the spiral wound gasket material was removed from the. reactor coolant system.
tX 'w A.similar inspection for debris on the fuel assemblies and lower core plate was performed during the Unit 2 core off-load. No'spiral wound gasket material was noted. As discussed in the licensee's response to Inspection Report No. 50-315/97004, letter AEP:NRC:1260C, dated June 5, 1997, the corresponding Unit 2 RHR heat exchanger valves, 2-IRV-310, 2-IRV-320, and 2-IRV-311 had their spiral wound gaskets replaced with compressed fiber gaskets prior to or during the Unit 2 1996 refueling outage.
The inspectors reviewed portions of the licensee's Unit 2 reactor vessel internals and fuel assembly inspection records and had no additional concerns.
The Unit 2 reactor vessel inspection results supported the licensee's conclusion that the spiral wound gasket replacements on 1[2]-IRV-310, 1[2]-IRV-320, and 1[2]-IRV-311 have prevented the introduction of gasket material into the reactor coolant system and reactor vessel.
The inspectors had no further concerns.
This violation is closed.
III. En ineerin E1 Conduct of Engineering E1.1 Closed Unresolved Item 50-315/96007-03 50-316/96007-03 0 erabilit of Essential Service Water ES With Ino erable Pum Dischar e Strainers Both Units a.
Ins ection Sco e 37551 As documented in Inspection Report No. 50-315/96007, during routine control room observations, the inspectors observed that an ESW pump discharge strainer had been removed from service without the associated ESW train being declared inoperable.
The inspectors questioned the adequacy of the licensee's basis for the strainers not being a support system required for ESW system operability. Pending additional information from the licensee the issue remained an Unresolved Item (50-315/316-96007-03).
The licensee supplied additional information to the inspectors, and the inspectors requested that the Office of Nuclear Reactor Regulation (NRR) review the licensee's design basis and reach a conclusion as to the need for operable strainers to support an operable ESW train.
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I'
b.
Observations and Findin s The inspectors reviewed the operating history of the ESW system for the past several years and found no instances where an ESW strainer had been removed from service for longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, the.TS limit.for inoperability of an ESW system train.
The ESW strainer backwash system was classified as a non-safety-related system.
However,.it was possible for,the strainers to be manually backwashed ifthe air system or the relays were to fail in order to support the continued operability of the ESW system.
In their response to the inspectors'equest to review this issue, NRR stated that the licensee should. consider any procedures for manually backwashing the strainers to be safety-related.
The licensee should also ensure that the emergency procedures for
.'esponding to'a loss of offsite power contain appropriate actions to take ifthe automatic
>> -strainer backwash capability was lost. However, a procedure to manually backwash the strainers did not exist, the evolution would require tools, and the operators were not trained in how to perform a manual backwash of the ESW strainers.
Technical Specification basis 3/4.7.4 for the ESW system stated, in part, "The OPERABILITYof the essential service water system ensures that sufficient cooling capacity is available for continued operation of safety-related equipment during normal
.
and accident conditions." [Original emphasis retained.] Title 10 CFR Part 50, Appendix B, Criterion V, "Instructions, procedures, and drawings," required, in part, that activities
..affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures or drawings.
Based upon the above information, the licensee failed to comply with Criterion V in that no procedures existed for the ESW pump discharge strainers manual backwash capability which was necessary to support the operability of the ESW system.
The licensee did not have the procedures, training, and tools necessary for manual backwashing.
This was considered a violation of 10 CFR Part 50, Appendix B, Criterion V (50-315/97024-02(DRP)); (50-316/97024-02(DRP)).
Conclusions The inspectors identified a violation in which the licensee failed to treat the manual backwashing of the ESW strainers in accordance with quality standards commensurate with the importance of the safety functions to be performed.
The licensee committed to complete the corrective actions necessary prior to placing either unit in Mode 4, Hot Shutdown.
IV. Plant Su ort Radiological Protection and Chemistry Controls (71750)
During the resident inspection activities, routine observations were conducted in the areas of radiological protection and chemistry controls using Inspection Procedure 71750.
No discrepancies were note S1 Conduct of Security and Safeguards Activities (71750)
During normal resident inspection activities, routine observations were conducted in the areas of security and safeguards activities using Inspection Procedure 71750.
No discrepancies were noted.
F1 Control of Fire Protection Activities (71750)
During normal resident inspection activities, routine observations were conducted in the area of fire protection activities using Inspection Procedure 71750.
No discrepancies were noted.
X1'xitMeeting The inspectors presented the inspection results to members of the licensee management at the conclusion of the inspection on December 29, 1997. The licensee had additional comments on some of the findings presented.
No proprietary information was identified by the licensee.
PARTIALLIST OF PERSONS CONTACTED Licensee
¹M. Ackerman, Supervisor, Nuclear Licensing
¹K. Baker, Manager, Production Engineering
¹S. Brewer, Director, Regulatory Affairs
¹S. Delong, Management Information
¹S. Farlow, Supervisor ILC Engineering
¹J. Fryer, Radiation Protection
¹R. Mankowski, Materials Management
¹D. Morey, Chemistry'Superintendent
¹A:Olvera, Nuclear'Licensing
¹F. Pisarsky, Superviso'r, Mechanical -Component Engineering
¹T: Postlewait,'Manager, Design Enginee'ring
"'P.
Russell, Supervisor, Plant'Protection
¹J. Sampson, Plant'Manager
¹P. Schoepf, Supervisor, Safety-related Mechanical Systems
¹J. Stubblefield, Supervisor, Scheduling
¹T. Szymanski, Plant systems
¹G. Tollas, Assistant Operations Superintendent
'I
¹Denotes those present at the December 29, 1997 exit meeting.
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IP 37001 IP 37551 IP 60710'P 61726 IP 62707 IP 71707
-'P 71750 IP 86700'
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'0 INSPECTION PROCEDURES USED 10 CFR 50.59 Safety Evaluations'n-site Engineering, ',-
Refueling Outage Surveillance Observations Maintenance Observation Plant Operations Plant Support Activities
'pent Fuel Pool Activities ITEMS OPENED and'CLOSED and DISCUSSED
,...,. ITEMS OPENED 50-315/97024-01 50-316/97024-01 50-315/97024-02 50-316/97024-02 50-316/97024-03 50-316/97024-04 50-316/97024-05 ITEMS CLOSED 50-315/96007-03 50-316/96007-03 50-315/97004-02b 50-316-97024-05 ITEMS UPDATED 50-316/97018-05 50-315/97018-06 50-316/97018-06 VIO.
Failure to maintain written safety evaluation VIO Failure to implement quality assurance commensurate with safety function URI Failure to have a valid surveillance test which proved operability of a TS required system URI Root cause and safety significance of the wrong containment airlock door seals NCV Failure to utilize the required safety-related parts URI Operability of ESW with inoperable discharge strainers VIO Spiral wound gasket material in reactor vessel NCV Failure to utilize the required safety-related parts IFI Poor material condition of the 2 AB D/G IFI D/G exhaust manifold brackets
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LIST OF ACRONYMS AEP ASTM bcc CC
CFR CR DCC
, DCP
,
" 'D/G DRP DPR ECCS EDT EHP ESF ESW FME IFI IR JO LOCA LOOP ME MHP MI NCV NOV NRC NRR OHI OHP OSO PDR PMP RHR SE SI SM SRO SCFM STP S/G SGRP TS UFSAR URI American Electric Povtter American Society forTesting and Materials blind carbon copy carbon copy
. " Code of.Federal Regulations Condition Report Donald C. Cook Design Change Package
,'Diesel Gerierator
'Division of Reactor Projects
'emonstration Power Reactor Emergency Core Cooling System Eastern Daylight Time
. Engineering Head Procedure Engineered Safety Feature Essential Service Water Foreign Material Exclusion Inspection Follow Up Item
Inspection Report
Job Order
Loss of Coolant Accident
Mechanical Engineering
Maintenance Head Procedure
Non-Cited Violation
Nuclear Regulatory Commission
Nuclear Reactor Regulator
Operations Head Instruction
Operations Head Procedure
Operations Standing Order
Public Document Room
Plant Manager's Procedure
Safety Evaluation
Safety Injection
Shift Manager
Senior Reactor Operator
Standard Cubic Feet per Minute
Surveillance Test Procedure
Steam Generator Replacement Project
Technical Specification
Updated Final Safety Analysis Report
Unresolved Item
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