IR 05000289/1999003
| ML20196H706 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/29/1999 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20196H685 | List: |
| References | |
| 50-289-99-03, 50-289-99-3, NUDOCS 9907060432 | |
| Download: ML20196H706 (20) | |
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U.S. NUCLEAR REGULATORY COMMISSION 9-REGION 1 Docket No.
50-289 License No.
DPR-50 Report No.
99-03 Licensee:
GPU Nuclear,Inc. (GPUN)
Facility:
Three Mile Island Station, Unit 1 Location:
P. O. Box 480 Middletown, PA 17057 Dates:
. April 25,1999 through June 5,1999 Inspectors:
Wayne L Schmidt, Senior Resident inspector Craig W. Smith, Resident inspector Approved by:
Peter W. Eselgroth, Chief Projects Branch No. 7 Division of Reactor Projects 9907060432 990629 PDR ADOCK 05000289
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EXECUTIVE SUMMARY Three Mile Island Nuclear Power Station Report No. 50-289/99-03 This inspection included aspects of licensee operations, engineering, maintenance, and plant support. The report covers a six week period of resident inspection.
GPU Nuclear, Inc. (GPUN) operated Three Mile Island Unit 1 (TMI) safely at 100 percent power
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Operations The shift operating c'3ws performed routine activities very well. Operators also responded properly to annunciated alarms. (Section 01)
Risk documents prepared to support work provided appropriate insight and areas of caution.
Shift supervision used the risk documents to perform good pre-job briefings. (Section O2.1)
GPUN submitted technical specification change request (TSCR) No. 265 to revise the shutdown decay heat removal requirements to be similar to the standard Babcock & Wilcox (B&W)
tecnnical specification (TS) requirements. Specifically, the TSCR would not allow the draining of the reactor coolant system (RCS) to a mid-loop condition with only one means of decay heat removal, as is currently allowed by the TS. (Section 08.1)
The May 13 initial operations corrective action process (CAP) operability assessment for the reactor building emergency cooler (RBEC) high cooling coil differential pressure was inadequate. FurtPr, by May 14 GPUN had not assessed the possibility that the RBEC performance could affect the planned reactor building spray (BS) system outage. (Section E2.1)
GPUN removed the A BS system from service, with the three RBECs in an unjustified degraded state of operability, between May 17 and 20. This was considered an unresolved item pending further review of the June 4 justification for continued operation (JCO), RBEC operating data, and the GPUN licensee event report (LER) on this issue. (Section E2.1) (URI 99-03-02)
The plant review group (PRG) performed the June 4 assessment of the RBEC degradation well.
Further, the associated JC0 discussion and the report made to the NRC for a condition outside the design basis were suitable. GPUN management appropriately questioned the May 17 PRG judgement that the RBECs were fully operable. (Section E21)
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Maintensings Preventive maintenance effectively identified a failed emergency feedwater (EFW) pump bearing, which GPUN properly responded to. As a result, the B motor-driven pump was considered inoperable for longer than the TS allowed out-of-service time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. He.vever, GPUN reasonably could not have known of the failed bearing based on past surveillance ii
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testing. This was an apparent escalated enforcement item pending NRC review of risk
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significance and the GPUN LER on this issue. (Section M2.1) (eel 99-03-01)
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The common cause evaluation was effective at assuring that the two other EFW pumps did not have similar bearing damage. Visualinspection of the bearing showed no damage. (Section l
M2.1)
GPUN properly planned and completed a single cell change-out on the A battery, while
. appropriately limiiing the battery out-of-service time to a minimum. (Section M2.2)
The electrical department continued to aggressively replace the commercial grade dedicated engineered safety actuation system (ESAS) relays that failed or that were hot or noisy. These work activities were conducted properly with appropriate post-maintenance testing (PMT). The failed relays and contacts have not caused any ESAS actuation logic to be inoperable.
Operators were made aware of manual actions that may be needed to reposition a failed relay if necessary to bypass the actuation logic. GPUN continues to seek the root cause of these relays failures and plans to submit a voluntary LER. (Section M2.3)
The maintenance department conducted a well-planned outage on the A decay heat removal train and the A BS system. (Section M4.1)
EneineerN System, component, and quality verification engineers provided excellent support during EFW pump corrective maintenance, battery cell replacement, ESAS relay work, and the decay heat removal and BS outages. (Sections M2.1, M2.2, M2.3, M4.1)
The high suction temperatures that occurred during EFW PMT caused engineering to identify a possible design deficiency with respect to the influence of the condensate system on EFW pump suction temperature. GPUN properly evaluated operability and was performing re-analysis of the suction temperature limits. (Section M2.1)
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System engineering and engineering in general performed well in identifying the degraded
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RBECs. Engineering was persistent in their review of data and industry information, and in the
completion of preliminary calculations to assess the extent of the degradation and to support the JCO. (Section E2.1)
GPUN identified that the pressurizer support botting would be overstressed if the seismic dampening factors used in the Updated Final Safety Analysis Report were applied. However, if the dampening factors used in Regulatory Guide 1.61 were applied the stresses would be within code allowable. rtegulatory Guide 1.61 was not currently incorporated in the plant design basis.
GPUN continued to review ways to correct the non-conforming condition. This was an unresolved item pending review of the calculation and corrective action plan. (Section E2.2)
(URI g9-03-03)
Several modification packages that GPUN plans to install during the upcoming refueling outage were well prepared. These modifcations will address potential pressure locking on decay heat lii
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removal valves and provide a high temperature isolation in the event of a makeup system F
letdown line break inside the auxiliary building. (Section E4.1)
The engineering review meeting provided a good forum for engineering to discuss and remain aware of ongoing problems, and gave management a chance to get an overview of issues and to provide unified guidance on further actions to be taken. (Section E6.1)
Plant Support The radiological control technician support during the observed portions of the decay heat removal outage was very good. The technicians provided realtime monitoring making the jobs go smoothly. Good contamination control techniques were used, and the workers were advised on the use of protective clothing and catch containment. (Section R1)
GPUN completed necessary repairs to return the waste evaporator condensate storage tank discharge line to service. Observed work in the field was conducted properly. Radiolcyical control technicians properly controlled the work areas to ensure no unmonitored releases occurred. (Section R8.1)
Security officers maintained good controls over personnel access to the protected area.
Further, on routine evening tours the protected arca lighting came on at dusk and provided suitable visibility. (Section S1)
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1, TABLE OF CONTENTS L
EXECUTIVE SUMMARY....................................................... ii
. TABLE OF CONTENTS........................................................ v 1. Operations............................................................... 1 l
Conduct of Operations............................................ 1
Operational Status of Facilities and Equipment........................ 1 02.1 Use of Multiple Risk Documents.............................. 1
Miscellaneous Operations issues (71701)............................ 1 08.1 - (Closed) Inspector Follow item 97-09-01; Refueling Decay Heat Removal Requirements............................................. 1 I I. Maintenance............................................................. 2 M1 Conduct of Maintenance (62707, 93702)............................. 2 j
M2 Maintenance and Material Condition of Facilities and Equipment..........
M2.1 Emergency Feedwater Pump Outboard Pump Bearing Failure and i
Subsequent inspections.................................... 2 l
M2.2 On-line Safety-Related Battery Cell Replacement................ 4 M2.3 (Update) Inspector Followup Item 98-08-02 - Failure of Engineered Safety Actuation System Relays and Replacements.................... 5 M4 Maintenance Staff Knowledge and Performance....................... 6 i
M4.1 Decay Heat Removal and Reactor Building Spray Outage.........
l I l l. Enginee ring.............................................................. 7
E2 Engineering Support of Facilities and Equipment (37551, 92903)..........
E2.1 Operability Of the Reactor Building Emergency Air Coolers.........
E2.2 Pressurized Support Bolting................................. 9 E4 Engineering Staff Knowledge and Performance....................... 10 E4.1 Outage Modification Package Reviews....................... 10
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E6 Engineering Organization and Administration......................... 11 E6.1 Engineering Review Group Meeting.......................... 11 E8-Miscellaneous Engineering issues (92903).......................... 11 i
~ E8.1 (Closed) Unresolved item 98-03-01; Adequacy of Controls over Reactor Building Tendon Access Gallery Flood Seals...................
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IV. Plant Support........................................................... 12
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R1 Radiological Protection and Chemistry (RP&C) Controls (71750).........
R8 Miscellaneous RP&C lasues (71750)............................... 12 R8.1 Repairs to Radioactive Liquid Waste Discharge Line.............
S1 Security (71750)............................................... 13 V. Management Meetings.................................................... 13 X1 Exit Meeting Summary........................................... 13
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INSPECTION PROCEDURES USED........................................... 14 h
ITEMS OPENED, CLOSED AND DISCUSSED................................... 14 i
LIST OF ACRONYMS USED................................................. 15 l
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Report Details Summary of Plant Status GPU Nuclear, Inc. (GPUN) operated Three Mile Island Unit 1 (TMI) at 100 percent power throughout the inspection period.
l. Operations
Conduct of Operations (71707)
The shift operating crews performed routine activities very well. Operators also responded properly to annunciated alarms. Specific events and noteworthy observations are detailed in the sections below.
O2 Operational Status of Facilities and Equipment O2.1 Use of Multiole Risk Documents a.
Insoection Scope The inspectors reviewed the risk documents associated with:
B motor-driven emergency feedwater (EFW) pump preventive maintenance (PM)
Online battery cell replacement
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Engineered safety actuation system (ESAS) relay replacement
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Turbine-driven EFW pump inspection
A motor-driven EFW pump inspection
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Condensate pump repacking,
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Conclusion Risk documents prepared to support work provided appropriate insight and areas of caution. Shift supervision used the risk documents to perform good pre-job briefings.
Miscellaneous Operations issues (71701)
08.1 (Closed) Inspector Follow Item 97-09-01: Refuelina Decav Heat Removal Reauirements On June 4, GPUN submitted technical specification change request (TSCR) No. 265 to revise the shutdown decay heat removal requirements to be similar to the standard Babcock & Wilcox (B&W) technical specification (TS) requirements. Specifically, the
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TSCR would not allow the draining of the reactor coolant system (RCS) to a mid-loop condition with only one means of decay heat removal, as is currently allowed by the TS.
The inspector closed this item.
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11. Maintenance M1-Conduct of Maintenance (62707,93702)
The inspectors observed the use of good work practice throughout the period.
M2 Maintenance and Material Condition of Facilities and Equipment M2.1 - Emeroency Feedwater Pumo Outboard Pumo Ramrina Failure and S$=== ant insnechons a.
Inspection Scope The inspectors observed portions of the work activities involved in the B motor-driven
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EFW pump PMs conducted on May 10. After this activity identified a failed outboard pump bearing, the inspectors observed the work needed to restore the pump to operability and the subsequent inspections necessary to ensure that the two other EFW
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pumps did not have a similar bearing problem.
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Observations and Findinas B Motor-Driven Preventive Maintenance:
On May 10, GPUN removed the B motor driven EFW pump from service to conduct PMs, which included changing the oil in the pump bearings. The inspector observed a proper equipment isolation and good work practices and supervision. The technician changing the outboard pump bearing oil noted that it appeared discolored with some suspended metallic particulab material. The maintenance department contacted the.
system engineer, and a plan to i.,vestigate the bearing condition was developed. Upon removing the bearing and cover, GPUN discovered that the intemal oil circulation disc was loose on the shaft and that the ess >ciated set screw was not in-place. Further, one of the series ball bearing cages was no longer intact.
Maintenance, engineering, and planning personnel worked well together to develop and carry-out the repair plan on the B motor-driven pump. The quality verification (QV)
organization provided appropriate oversight. The inspector observed the gathering of necessary parts and the inspection of the bearing intamals once removed. The repair activities took approximately two-days and were completed by an appropriate post-maintenance test (PMT) including the pump inservice test (IST).-
Based on the condition of the bearing at the time of the PM, the inspector and GPUN concluded that the pump was inoperable since the performance of the last IST. The IST was last run in February 1999, and the pump had to be started for a logic test in March 1999. As such, the B motor-driven pump was inoperable for longer than the TS allowable time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The inspector determined that GPUN reasonably could not have known of the failed bearing based on past surveillance testing. Further, at several times in the interim GPUN took various other pieces of EFW equipment out-of-service for i
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testing. This was a TS violation and an apparent escalated enforcement issue (EEI).
f GPUN committed to submit a licensee event report (LER) on the pump bearing failure.
j The eel will remain under review pending NRC assessment of the safety risk for the time the 8 motor-driven EFW pump was considered inoperable and pending review of the LER. (eel 99-03-01)
Common-Cause insoections:
Engineering addressed the short term question of common mode failure of the similar bearing on the other two pumps by reviewing vibration data taken during the February 1999 IST to see if there was a discernable difference between the A and B motor-driven and the turbine-driven pumps. Engineering identified that none of the pumps exceeded any IST vibration limits; however, the B motor-driven pump showed a shift in the frequency of the vibration. For the A motor-driven and the turbine-driven pumps there was no discemable vibration frequency difference. This gave GPUN some confidence that the other pumps did not have a common mode failure probikm. GPUN inspected the other two pump bearing on May 26 and 27, confirming that there was no damage.
Turbine-Driven Pumo Po' -Maintenance Test:
Following disassembly of the turbine-driven pump outboard bearing and the identification of no damage, GPUN ran the pump IST to verify operability for PMT. During this run the bearing cooling water and suction temperatures were observed to be high at 138'F and the operators shutdown the pump.
GPUN determined that the ab'ormally high temperatures possibly resulted from the condensate system being its a special test configuration that allowed the condensate system miscellaneous drain col ection tank (MDCT) to pump to the condenser hot well through the normal condenser makeup path which is common to the B condensate storage tank (CST) suction to the EFW pumps. The MDCT water was approximately 140*F. Due to the configuration, if the condenser level control system was not calling for makeup flow, the hot water was being pumped to the B CST, which once the EFW pump started allowed it to be pumped directly to the pump suction. Engineering also questioned whether the normal letdown of condensate on high condenser water level could cause this problem since this was also hot and fed into the common B CST suction to the EFW pumps.
GPUN stopped pumping the MDCT to the condenser hot well and continued their review l
of the condensate system interactions with the EFW suction temperature. GPUN generated corrective action process (CAP) 1999-442 to document the problem and the associated corrective actions.
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GPUN evaluated the effect on the operability of the EFW pumps with the 138'F elevated suction temperature, above the design assumption of 120*F, as minor. The higher temperature water being supplied to the once through steam generators could be compensated for by approximately 10 gpm additional EFW flow above the minimum required by the design analysis. The inspector verified that sufficient margin existed,
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between the minimum design analysis flow and the actual achievable EFW pump flow, to accommodate the additional 10 gpm.
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Conclusion PMs effectively identified a failed EFW pump bearing, which GPUN properly responded to. However, as a result, the G motor-driven pump was considered inoperable for longer than the TS allowed out-of-service time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. However, GPUN reasonably could not have known of the failed bearing based on past surveillance testing. This was an apparent eel pending NRC review of risk significance and the GPUN LER on this issue.
The common rause evaluation was effective at assuring that the two other EFW pumps did not have similar bearing damage. Visualinspection of the bearing showed no damage.
The high suction temperatures that occurred during EFW PMT caused engineering to identify a possible design deficiency with respect to the influence of the condensate system on EFW pump suction temperature. GPUN properly evaluated operability and was performing re-analysis of the suction temperature limits.
System, component and QV engineers provided excellent support to the review and development of a repair plan for the B motor-driven EFW pump and in the common mode failure assessment and inspections for the other pumps.
M2.2 On-line Safetv-Related Batterv Cell Reo acement a.
Inspection Scope The inspectors reviewed the planning for and observed the replacement of the #6 battery cell on the A battery bank following GPUN identification of lower than expected cell voltage and inability to retum it to a stable voltage.
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Observations and Findinos The planning effectively staged spare battery cells in a temporary seismic rack and the
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cabling needed to jumper these spare cells around the cell to be replaced. The planning i
also included staging the apprnpriately tested replacement cell.
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The replacement process went very smoothly with no specific problems. Jumpering-in of
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the spare cell to the battery bank was done using good precautions for matching voltages. These jumpered-in spare cells allowed the cell to be replaced to be electrically disconnected from the battery, while maintaining the A battery in an operable condition.
GPUN appropriately considered the A battery inoperable for the 45 minutes it took to:
. remove the seismic support, remove the old cell, put the new cell in place, and reinstall the esismic support I
System engineering provided good suppor' nd oversight of the single cell replacemen.
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Conclusion GPUN properly planned and completed a single cell change-out on the A battery, while appropriately limiting the battery out-of-service time to a minimum.
System engineering provided good support and oversight of the single cell replacement.
M2.3 (Uodate) Insoector Followuo item 98-08-02 - Failure of Enair.n ed Safety Arbatian System Relays and Replacements a.
Inspection Scope The inspectors continued to follow the actions being taken on the commercially grade dedicated AO Smith ESAS relay failures and overheating as documented in this inspector followup item (IFI). Over this period, several more relays failed and several were replaced due to overheating and coil humming.
- The inspectors observed relay replacement and reviewed the PMTs on five relay coils and a contact block on each of two relays. These relays are unique in that a contact block can be replaced without changing the entire relay or disconnecting all of the contact blocks.
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Observations and Findinos The technician conducted the observed relay work very well, with excellent engineering and QV support. Minor conditions ' ere documented to allow further engineering review j
w of the root cause for the relay problems. Further, one entire relay assembly was replaced to allow testing at a laboratory for root cause investigation.
Technicians performed the Monthly Channel Functional Surveillance Test (1303-4.13),
as the PMT for the affected reactor building isolation and cooling logic. The inspector
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reviewed the job order, surveillance test, elementary schematic drawings, and panel wiring drawings. The surveillance test adequately demonstrated change-of-state j
functionality for the replaced relay coils and contact blocks. The affected contact blocks were for indication circuits and did not affect any control or logic functions.
During this period, as a result of the number of relay problems, GPUN determined that they would submit a voluntary LER to inform the NRC and the industry of these problems.
The failures have occurred on relays when they were reenergized to their unactuated (normal standby) state following actuation during system testing. The hot and noisy
,. relays would have failed to the actuated (deenergized) state if they continued to overheat. In no cases, did a relay not properly reposition to its actuated state upon receipt of a simulated ESAS signal. However, the concern remains that if an actuation relay failed to reenergize property it may not permit the operators to bypass the actuation
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logic. The operators were aware of the possible bypass problems and the actions to take to manually reposP. ion a reiay if needed to bypass an actuation.
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Conclusion The electrical department continued to aggressively replace the commercial grade l
dedicated ESAS relays that failed or that were hot or noisy. Thea work activities were i
conducted property with appropriate PMT. The failed relays and contacts have not I
caused any ESAS actuation logic to be inoperable. Operators were made aware of manual actions that may be needed to reposition a failed relay if necessary to bypass the actuation logic. GPUN continues to seek the root cause of these relays failures and plans to submit a voluntary LER.
Systems engineering and QV provided good support for the ESAS relay work.
M4 Maintenance Staff Knowledge and Performance M4.1 Decav Heat Removal and Reactor Buildino Sorav Outaae j
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inspection Scope The inspectors reviewed the planning for and the conduct of work during the A decay-heat removal (decay heat (DH), decay closed (DC) and decay river (DR) systems) and the A reactor building spray (BS) system outage conducted the week of May 18.
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Observa0ons and Findinas The decay heat removal outage went very well except for some problems with the draining. Supervision demonstrated good support of the work. Engineering support was also very visible. On the observed jobs, maintenance technicians conducted the work activities well demonstrating good use of procedures and skills of the trade. Radiological control support was excellent for the several jobs observed.
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GPUN observed that the A DH pump had vibration readings above the established alert action level during system IST. The IST engineer evaluated that the vibrations were possibly due to air pockets in the lines, which had been drained for the outage work. No work had been done on the pump that would have affected the vibration readings.
GPUN planned to vent the DH system in the reactor building (RB) and perform the IST at the increased six-week interval.
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Conclusion The maintenance department conducted a well planned outage on the A decay heat
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Engineering provided good support to IST and modification work.
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Radiological protection technicians provided excellent support for the observed work activities, j
i 111. Enaineerina E2 Engineering Support of Facilities and Equipment (37551,92903)
E2.1 Qg ibility Of the Reactor Buildina Emeroency Air Coolers -
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10 '., tion Scone The inspector observed GPUN actions in response to suspected degradation of the reactor bui! ding emergency cooler (RBEC) air flowrates.
The RBECs are required to remove heat from the RB following the design basis loss of coolant accident to limit containment pressure and maintain the temperature profile
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within the environmental qualification of installed equipment. By design the RBEC work in conjunction with the BS system. Per TS, two of the three RBECs need to be operable, along with the two BS trains, to allow for a single failure. Per the TS basis the following combination will meet the accident analysis for RB cooling: one RBEC and one BS train, two BS trains, or three RBECs.
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Each of the three RBECs has two inlet air paths to a single two-speed fan. !n each of the inlet flow paths there are: a metal pre-filter, a normal cooling coil (supplied by a non-safety-related closed cooling system) used to maintain RB temperatures during operation, and an emergency coil (supplied by the safety-related reactor river water (RR)
system) used to remove the accident heat load. The safety-related coils normally do not have cooling water flow and are laid up with a corrosion inhibitor in them. Under normal operating conditions, the fans run in fast speed; under accident conditions, the fans trip and re-start in slow speed with RR flow.
Installed system monitoring instrumentation is limited to local differential pressure instruments around one set of coiling coils (pre-filter, normal and emergency coiling i
coils) on each RBEC. To determine actual flowrates the velocities in the four downcomers, which supply the three RBECs, need to be measured using an anemometer. GPUN routinely conducts slow speed flow measurements during refueling outages.
TS require that the average RB temperature above elevation 320' be maintained less
. than 130*F, Operators monitor RB temperature with a strip chart recorder. If an upper elevation temperature reaches 130*F, the operators receive an alarm and must perform a hand calculation to ensure that the average 130*F is not exceeded.
During the operating cycle, RCS unidentified leakage has been consistently between 0.1 and 0.3 gallons per mirsute (gpm); the TS limit is 1.0 gpm. GPUN was in the process of conducting c root cause analysis of this leakage. Since the RCS water contains boric m
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acid, GPUN was looking for, but up to this point had not noted, any large boron deposits in the RB.
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Observations and Findinas During the week of May 10, while investigating what appeared to be higher than expected (less that 130*F average) RB temperatures, the system engineer determined that the differential pressure on all three operating RBECs was higher than previously expected. The engineer documented this on CAP 1999-0407, dated May 12.
In reviewing the May 13 operability justification for CAP T1999-0407, the inspector found that the shift supervisor was basing operability on a flow measurement conducted during the last refueling outage in the Fall of 1997. On Friday, May 14, the inspector questione f if entry into the planned A BS outage on the following week was considered appropriate with the possibly degraded RBEC air flow. Over the weekend maintenance removed the pre-filters from all the RBECs with little effect on the differential pressure. Maintenance technicians then used a water lance to spray the C RBEC normal cooling coils, again with little change in differential pressure. Engineering continued to review the RBEC operation and discussed the coolers parameters with a vendor. Operations collected I
additional historical data.
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The plant review group (PRG) met on Monday, May 17, and determined that based on the data at hand there was no specific reason to doubt that the coolers were operable, and the decision was made to go ahead with the A BS outage. Engineering presented i
information from the vendor that the condensation of the 0.3 gpm RCS leakage on the I
coil could be accounting for the differential pressures. PRG also determined that it was not necessary to conduct actual air flow measurements in the RBECs. The A BS system j
was removed from service on May 17 and remained inoperable for approximately 66 hours7.638889e-4 days <br />0.0183 hours <br />1.09127e-4 weeks <br />2.5113e-5 months <br />.
During the weeks of May 24 and May 31, ambient temperatures continued to increase, as did the average RB temperature. GPUN discussed the possible need to operate the RR system to supply water to the RBEC emergency coils to bring the RB temperature down if it exceeded the 130*F average. At this point, engineering had enough j
information to question the May 17 operability determination. Further, GPUN became
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aware of industry information that showed that other plants, that had RCS leakage, needed to remove boron deposits from their cooling coils using high ternperature water i
spray.
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On June 4, fast speed flow measurements were conducted showing approximately 40 I
percent degradation from previous values. The PRG met and determined that the flowrates through the coolers in slow speed would be less than the 25,000 cubic feet per minute (cfm) referenced in the updated final safety analysis report (UFSAR).
Engineering estimated that the flowrates would be close to 17,000 cfm, but used a 15,000 cfm number to determine that the coolers could perform their design function if the RR and borated water storage tank (BWST) temperatures were limited to less than their design value of 95'F and 120*F, respectively. The PRG accepted this engineering
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judgement, and engineering proceeded to prepare a justification for continued operation (JCO), as maintenance and operations prepared to conduct coil cleaning. On June 4
GPUN reported the condition of the RBECs to the NRC as a condition outside of the j
plants design basis.
GPUN also initiated a CAP to investigate the May 17 PRG determination that the coolers
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were fully operable.
The inspector considered this an unresolved item (URI), pending review of the documented JCO, the results and analysis of the subsequent cleaning, and the GPUN LER to determine the ability of the RBECs to perform their design function while the A j
BS system was removed from service. (URI 99-03 02)
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Conclusion The May 13 initial operations CAP operability assessment for the RBEC high cooling coil differential pressure was inadequate. Further, by May 14 GPUN had not assessed the possibility that the RBEC performance could affect the planned BS system outage.
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GPUN removed the A BS system from service, with the three RBECs in an unjustified
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degraded state of operability, between May 17 and 20. This was considered an
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unresolved item pending further review of the June 4 JCO, RBEC operating data, and l
the GPUN LER on this issue.
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The PRG performed the June 4 assessment of the RBEC degradation well. Further, the
' associated JCO discussion and the report made to the NRC for a condition outside the design basis were suitable. GPUN management appropriately questioned the May 17 PRG judgement that the RBECs were fully operable.
System engineering and engineering in general performed well in identifying the degraded RBECs. Engineering was persistent in their review of data and industry information, and in the completion of preliminary calculations to assess the extent of the degradation and to support the JCO.
E2.2 ~ Pressurized Suooort Boltina a.
Insoection Scope The inspectors reviewed GPUN actions v hen an unverified calculation indicated that the stresses in the pressurizer support bolts were above the American Society of Mechanical Engineers (ASME) Code allowable va';es. This calculation used the UFSAR seismic dampening factors and was being conducted as a reverification of the RCS stress analysis.
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Observations and Findinas l
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l-Based on new analysis of the stress, GPUN reported that the stresses using the UFSAR seismic dampening factor exceed the ASME Code allowable values. GPUN completed additional calculations using the dampening factors in Regulatory Guide 1.61 and the stresses were within code allowable. However, Regulatory Guide 1.61 was not part of the current plant design basis.
i The PRG determined that this issue was reportable to the NRC on May 25 as a condition outside the design basis. This issue was captured in CAP 1999-0264. GPUN was in the process of verifying the stress calculations and preparing a plan to address the non-conforming condition, as well as determining if a modification was needed or if a change to the UFSAR was appropriate. This was considered an unresolved item pending further review of the calculation method used and the GPUN justification for the use of the Regulatory Guide 1.61 dampening factors. (URI 99-03-03)
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Conclusion i
GPUN identified that the pressurizer support bolting would be overstressed if the seismic dampening factors used in the UFSAR were applied. However, if the dampening factors used in Regulatory Guide 1.61 were applied the stresses would be within code allowable. Regulatory Guide 1.61 was not currently incorporated in the plant design basis. GPUN continued to review ways to correct the non-conforming condition. This was an unresolved item pending review of the calculation and corrective action plan.
E4 Engineering Staff Knowledge and Performance E4.1 Outaae Modification Packsoe Reviews a.
Inspection Scope The inspector discussed and reviewed several planned outage modifications with the makeup system engineer, including:
MD-G973-001; DH-V0001 and DH-V0002 Pressure Locking Modification
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MD-G974-001; High Temperature isolation of Letdown Line
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b.
Observations and Findinas The inspector found the modification packages and the associated safety evaluations properly prepared.
MD-G973-001 will address possible pressure locking problems with the two decay heat removal isolation valves which are located in the RB. The pressure locking of these valves could make it difficult to get into decay heat cooling with the decay heat removal system following a depressurization of the RCS. The modification will entail the installation of bypass piping that will allow the depressurizing of the area between the discs of theses gate valve a
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MD-G974-001 will install temperature sensors on the letdown piping just after it passes through the RB wall to the auxiliary building (AB). These sensors will supply a high
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temperature isolation circuit that will automatically close the letdown inside and outside containment isolation valves, MU-V 2A and 28 and MU-V3, respectively. This isolation will limit the effects of a letdown pipe break inside the AB.
c.
Conclusion Several modification packages that GPUN plans to install during the upcoming refueling outage were well prepared. These modifications will address potential pressure locking on decay heat removal valves and provide a high temperature isolation in the event of a makeup system letdown line break inside the AB.
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E6 Engineering Organization and Administration E6.1 Enaineerina Review Group Meeting a.
jngpaction Scooe The inspector attended the May 24 engineering review meeting.
b.
Observations and Findinas This meeting presented a good summary of current engineering issues. Issues discussed included EFW, pressurizer supports, RBECs, TSCR 279, and Y2K planning.
This was viewed as a good initiative to keep engineers and their management aware of current problems. It also allowed management to provide unified guidance on further actions to be accomplished.
c.
Conclusiog The engineering review meeting provided a good forum for engineering to discuss and remain aware of ongoing problems, and gave management a chance to get an overview
- of issues and to provide unified guidance on further actions to be taken.
ES Miscellaneous Engineering issues (92903)
E8.1 (Closed) Unresolved item 98-03-01: Adeauacy of Controls over Reactor Buildina Tendon Access Gallery Flood Seals I
GPUN completed a review of the identified condition where portions of the seal between the outside and the tendon access gallery were degraded. Upon identification maintenance resealed the degraded area. This review was documented in CAP 1998-
< 0985, which was subsequently closed by completion of engineering task tracking item 1429 '
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i The inspector found that the UFSAR, while not specific, required that the barrier be sealed and that the as found seal area represented a degraded condition as discussed in the CAP. Further, the inspector found that engineering took appropriate actions to address the issue. As such, the inspectordetermined that GPUN had not violated 10 j
CFR 50.59, since the UFSAR did not need to be changed. Further, the inspector concluded that with the high water level alarm in the tendon access gallery and actions which could be taken to limit the water flow through the degraded seal, this issue was of minor safety significance. The inspector closed this unresolved item.
IV. Plant Support-R1 Radiological Protection and Chemistry (RP&C) Controls (71750)
The radiological control technician support during the observed portions of the decay
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heat removal outage was very good. The technicians provided realtime monitoring making the jobs go smoothly. Good contamination control techniques were used, and
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the workers were advised on the use of protective clothing and catch containment.
R8 Miscellaneous RP&C lesues'(71760)
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R8.1 Repairs to Radioactive Liould Waste Discharoe Line c.
Insoection Scope The inspectors continued to follow GPUN actions to address the identification of a leak from the waste evaporator condensate storage tank (WECST) radioactive liquid waste discharge line, as discussed in NRC Integrated Insp6ction Report No. 50-289/99-01, dated April 16,1999. That report concluded there were no radiological consequences to the public as a result of the leak and that GPUN intended to repair or replace the WECST discharge line.
b.
Qhservations and Findinas GPUN completed repairs to the WECST discharge line and the line was retumed to service on May 7. Approximately 70 feet of piping was replaced. Of that, less than ten feet showed evidence of extemal corrosion. Two through-wall leaks were !dentified in the ten foot section. The cause of the corrosion was failure of the external protective coating. There was no corrosion identified on any of the other piping sections that were examined. Following repairs, the discharge line was successfully leak checked using a 10 pounds per square inch (psi) air pressure test. The final field connection was visually inspected during a subsequent in-service test.
c.
Conclusion
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GPUN completed necessary repairs to return the WECST discharge line to service.
Observed work in the field was conducted properly. Radiological control technicians properly controlled the work areas to ensure no unmonitored releases occurred.
S1 Security (71750)
Security officers maintained good controls over personnel access to the protected area.
Further, on routine evening tours the protected area lighting came on at dusk and provided suitable visibility.
V. Manaaement Meetinas X1 Exit Meeting Summary
Following the conclusion of the inspection period, the inspectors conducted an exit meeting w;th GPUN managers on June 16. GPUN staff comments concerning the issues in this report were documented in the applicable report sections. No proprietary information was include _.
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INSPECTION PROCEDURES USED IP37551 Onsite Engineering IP62707 Maintenance Observation IP71707-Plant Operations IP71750 Plant Support Activities -
lP92903 Engineering Followup IP93702 Event Response ITEMS OPENED, CLOSED AND DISCUSSED Opened 9p-03-01 eel 2B EFW pump being unknowingly inoperable for greater than the TS allowed out of service time, due to an undisclosed bearing failure.
99-03-02 URI Reactor building emergency coolers in a degraded state when the A building spray system was removed from service for maintenance.
99-03-03 URI Review pressurizer support bolting calculations and seismic dampening assumptions and corrective actions to address the non-conformance.
Closed:
97-09-01 IFl Refueling Decay Heat Removal Requirements 98-03-01-URI Adequacy of Controls over Reactor Building Tendon Access Gallery Flood Seals Discussed.
98-08-02 IFl Failure of Engineered Safety Actuation System Relays and Replacements
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LIST OF ACRONYMS USED AB Auxiliary Building ASME American Society of Mechanical Engineers
. B&W Babcock and Wilcox BS
. Reactor Building Spray (ECCS)
BWST Borated Water Storage Tank CAP Corrective Action Process ofm ~
cubic feet per minute CST Condensate Storage Tank
DH.
DR Decay Heat River (ECCS)
eel Escalated Enforcement item EFW Emergency Feedwater ESAS Engineered Safety Actuation System
- gpm gallons per minute GPUN GPU Nuclear, Inc.
IFl inspection Followup item IR inspection Report IST-Inservice Test JCO Justification for Continued Operation LER Licensee Event Report.
MDCT Miscellaneous Drain Collection Tank z NRC
_ Nuclear Regulatory Commission PDR Public Document Room PM-Preventative Maintenance PMT Post-Maintenance Testing PRG Plant Review Group psi -
pounds per square inch QV Quality Verification RB Reactor Building _
RBEC Reactor Building Emergency Cooler
. RCS..
Reactor Coolant System RP&C Radiological Protection and Chemistry RR
. Reactor River Water System (ECCS)
TMI Three Mile Island-Unit 1 TS Technical Specification
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- TSCR'
Technical Specification Change Request
.UFSAR Updated Final Safety Analysis Report o
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' URl'
Unresolved item
' WECST-
. Waste Evaporator Condensate Storage Tank