IR 05000458/1990028
| ML20058B024 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 10/17/1990 |
| From: | Stetkay T, Wagner P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20058B016 | List: |
| References | |
| 50-458-90-28, GL-89-10, NUDOCS 9010290356 | |
| Download: ML20058B024 (7) | |
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APPENDIX U.S. NUCLEAR REGULATORY COMt11SS10N
REGION IV
NRC Inspection Report: 50-458/90-28 Operating License: HPF-47 Docket: 50-458 Licensee: GulfStatesUtilities(GSU)
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P.O. Box 220 St. Francisville Louisiana 70775 Facility Name: RiverBendStation(RBS)
Inspection At: RBS, St. Francisville, Louisiana j
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Inspection Conducted: October 9-12, 1990 at RBS
/ O// 7/90 Mak Inspector:
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Reacty Inspector, Plant Systems P. C. Wagner
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Section, Division of Reactor Safety
/r;//v/9s Approved:
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T. F. Stetka, Chief Plant Systems Section Division of Reactor Safety
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Inspection Summary inspection Conducted October 9-12.1990(Report 50-458/90-28)
r Routine, unannounced inspection of the'insta11ation and Areas Inspected:
testing (ofmodificationsandtheinstallationofheatshrinkableinsula I
tubing HST).
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previous inspection findings.
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Results; Within the areas inspected, no violations or deviations were
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identified. The inspector found the actions'taken in response to concerns raised'in a previous inspection of motor operated valves (MOVs), to be
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acceptable. The inspector noted, however, that criteria established to determine the acceptability of certain MOVs had not been incorporated into facility procedures even though the corrective actions had been. completed i,
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for a period of 17 months.
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' The. inspector also found the-HST installations and the installation and
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testing of modifications to be acceptable. However, the need for numerous
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' changes to the modification work packages may be indicative of a lack of
.< attention to detail by the engineers performing the design efforts,
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-3-DETAILS 1.
PERSONS CONTACTED 1.1 GSU PERSONNEL
- D. Andrews, Director, Nuclear Training
$J. Cooker, Manager, RBS Oversight J. Cook, Technical Assistant Licensing D. Derbonne, Assistant Plant Manager, Maintenance
- L. England, Director Nuclear Licensing J. Frick, Electrical Maintenance Supervisor
- K.Giadrosich,QualityAssurance(QA) Supervisor
- P. Graham, Plant Manager
- G. Hendl, Senior Compliance Analysis
- G. Kimell, Director, Quality Systems
- D. Lorfing, Supervisor, Nuc1 car Licensing
- I. Malik, Supervisor, Operations QA J. Mead, Supervisor, Electrical and Special Projects
- W. Odell, Manager, Administration
- J. Pruitt, Manager, Business Systems
- J. Simpson, Maintenance Supervisor
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- A. Soni, Supervisor, Equipment Qualification
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- K. Suhrke, General Manager, Engineering and Administration
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1.2 NRC FERSONNEL
.t E. Ford, Senior Resident Inspector, RBS D. Lovelace, Resident inspector, RBS
- Indicates those persons who attended the exit meeting held on October 12, 1990.
The inspector also contacted other licensee and contractor personnel during the course of the. inspection.
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2.
LICENSEE ACTIONS ON pREVIOUSLY IDENTIFIED INSPECTION FIND 1 HGS (92701)
2.1 (Closed)UnresolvedItem(458/8802-02): MotorOperatedValve.(MOV) thrust calculations.
During.the previous inspection, the inspector determined that the licensee had.-
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set the closing torque switch on six MOVs at a value higher than the torque
. capability of the motor when the terminal voltage was degraded. The inspector was concerned that one or more of the motor actuators would either fail or be
tripped by electrical protective devices prior to producing.the necessary
' torque.
In response to this concern,-the licensee reevaluated each actuator's capabilities by performing testing to determine the actual thrust being c
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f-4 applied to the valve stem. The licensee used the thrust values determined by testing in order to calculate the maximum torque potential of the actuator.
1he licensee determined that the capability of each of the six actuators was
_tgreater than that required even under degraded voltage conditions.
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~ During this inspection, the inspector was inforu d that the licensee was response to NRC Generic Letter (GL) 89-10, gram for all safety-related MOVs in implementing a testing and reevaluation pro Safety-Related Motor Operated Valve Testing and surveillance." The licensee was reevaluating the thrust required a
to position the involved valves under worst-case conditions and was evaluating the actuators' capabilities to provide that thrust.
The inspector was also informed that the evaluations would include a study of the potential terminal voltage conditions at the actuator motor. Since the torque capability of AC induction motors decreases by the square of the voltage
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reduction from nominal, significant reduction in actuator capabilities occur as the terminal voltage at the motor deceases.
For example, the degraded voltage condition had been considered to be 80 percent of nominal for most applications which resulted in a 64 percent reduction in torque capability. However, the-licensee's study for one of the six POVs involved in this finding determined that the lowest voltage condition would be only 89 percent of nominal, which results in a reduction in torque capability to 79 percent. This equates to a 23 percent higher. torque capability than had been assumed in previous
calculations.
Since the licensee had verified that the actuators had sufficient capabilities, and since additional inspections will be conducted of the licensee's program i
for testing MOVs in response to GL 89-10, this unresolved item is closed.
2.2 (Closed)Unresolveditem(458/8802-03):
Lack of guidance for backseating of valves.
During the previous inspection, the inspector identified four MOVs which were i
being backseated with various amounts of thrust. ~ The valve actuators should
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have been adjusted so that an open direction limit twitch would remove power to the actuator's motor at approximately 95 percent of the open cycle, in some
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- aaplications, only one set of limit switches were included in the actuator.
Taerefore, if the open limit switch was set to reposition at 95 percent of
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travel to protect the actuator, the position indicacion would be incorrect; if m
the. limit switch was repositioned at_100 percent, the position indication would-
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be correct but the backseating force could be excessive and damage the valve.
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The licensee evaluated the condition of each of the four-identified valves in y
accordance with backseating criteria established in Engineering Evaluation and Assistance Request (EEAR) 88-R0101. The EEAR was written in response to the
findings in NRC Inspection Report 50-458/88-02_and established the following
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backseating criteria:
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"If the valve is backseating, inspect the torque switch to determine if The backseating torque is enough to open the opening torque switch, i
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If the opening torque switch has not opered, then reset the open limit switch to prevent the backseating.
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If the opening torque switch has opened, then inspect the velve stem for evidence of cracks or thread darage.
If no stem damage is found, then reset the open limit to prevent the backseating.
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If evidence of stem damage is found, then initiate a Condition Report to have Engineering evaluate the condition of the MOV."
The licensee implemented this backseating criteria on each of the four MOVs and made adjustments to either the open limit twitch and/or the open torque switch.
The licensee did not identify any unacceptable damage to any of the valves during the inspections or evaluations.
The inspector questioned why the above criteria was not incorporated into the CorrectiveMaintenanceProcedure(CMP)forMCVs(CMP-1253). The inspector was informed that an apparent oversight had occurred but that the backseating criteria would be added to CMP-1253 by October 23, 1990, in accordance with GSU internal memorandum TRAC 8660.
l Since the four valves in question were determined to be operable by the licensee and since backseating criteria will be included in the CMP and
'GL 89-10 testing provisions, this unresolved item is-closed.
3.
HEAT SHRINKABLE TUBING (Tl2500/17)
Theinitialinspectionoftheheatshrinkabletubing(HST)installationsatthe RBS was documented in NRC Inspection Report 50-458/89-23 dated May 30, 1989.
The inspection of HST remained open 73nding evaluation of the licensee's actions in response to identified procedural shortcomings and the physical inspection of HST installations. Subsequent to that inspection, the licensee completed the evaluation of procedure concerns documented in Condition j
Report (CR)86-035. The CR documented deficiencies with facility procedures related to, among other items, the instt11ation of HST. The involved Corrective Maintenance Procedures (CMps) did not contain the detailed instructions which had beenincludedintheElectricalInstallation/DesignSpecification(#248.000)
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utilized during the construction of RBS.
The licensee reviewed the maintenance activities which had been conducted from December 1984 through June 1986 and determined that 1,080 Maintenance Work-
. Orders (MW0s).hadinvolved-theuseofthequestionedCMPs. These 1,080 MW0s were evaluated to determine if the installation of HST could have been included-in the work activities. The licensee determined that all but seven of the MW0s were acceptable and performed physical inspections of the seven for which
. conclusive information was not documented.. The licensee's inspections determined that only one of the installations deviated from the application guidance of the HST manufacturer. This installation.was determined to be acceptable based on its location in a mild environment (the Emergency Diesel Generator Room) but was reworked to provide the recommended seal length in order to conform with manufacturer's guidance.
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E The corrective action recommended by CR 86-035 to prevent recurrence included
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the revision of the involved CMPs. The inspector's review of CMP-1277,
" Lugging, Splicing and Termination of Poter, Control and Instrumentation Cables," disclosed references in Section 8.0, " Application of Raychem Heat Shrink," to the various manufacturer's Installation and Selection Guides.
-t-The inspector performed visual inspections of approximately eight HST installations at the RBS. The installations included medium and low voltage AC power, AC control, and DC power cable size reduction splices. These splices were inspected to ensure that the HST had a smooth and contoured eFterior
- surface, appropriate length, and a visible flow of the red adhesive from the
,i ends.
The inspector found both the resolution of CR 86-035 and the installed HST l
installations to be acceptable.
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4.
INSTALLATION AND TESTING OF MODIFICATIONS (37828)
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The direct observation of work activities associated with the installation of-facility hardware modifications was included in this inspection. These
- observations were conducted to ensure that the work was being performed by i
. qualified workers in accordance with approved instructions, procedures and/or
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' drawings contained in the work package.
The: inspector reviewed the listing of ongoing work activities and selected a imodification: package involving changes to the control panel indications for detailed inspection., Modification Request (MR) 87-0576 was approved on j
- Jamary 5',-1988.; The MR requested that indication of the status of the Nuclear-
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Steam Supply Shutoff System (NSSSS) be provided on the main control-panel
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The NSSSS consists of six groups of valves each controlled by a-
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-one-out-of-two-takenitwice logic-(i.e., either of two inputs from;one trip.
' system:provided a partial or 1/2 isolation signal;.if the other trip system
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":also provided aL1/2Lisolation signal, an isolation would occur).- The NSSSS is
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described in Section '7.3.1.1.2 of: the-RBS Updated Saf ety Analysis
1 Report--(USAR)='
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The modification activities were being implemented in accordance with
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(Maintenance' Work Order (MWO) R126467.. The MWO contained step-by-step >
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- instructions which mainly referenced the appropriate Attachments in MR 87-0576.
The inspector.found the installation and testing _ instructions to be acceptable.:
The inspector dk.ote,Lhowever, that among the relays that 'were being rewired were some Potter and Brumfield.MDR type relays. The inspector' questioned the-g'
- licensee'to' determine if those relays were the'same:model'MDR type ' relays that'
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ihad been the subject of an industry problem reported to the NRC in accordance
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' owith 10 CFR Part 21 (HRC Tracking item 88-10). -The -licensee verified that the'
- RBS relays were not the_ same as those in question..
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.s.; s m-7-A conditional release to install the new electrical cables and components - but not: tie-in or energize the equipment - was granted on_ September 30, 1990. The
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electrical cable installations were completed, but mounting problems were encountered with the new relays and fuse holders.
In order to resolve these
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l problems and provide alternate mounting instructions, a field Change Notice (FCN) was requested on October 9,1990. Work was halted pending approval of the FCN.
Since the approval of the FCN for the above work was delayed a number of times, the inspector selected _another modification in order to observe ongoing work.
The inspector selected a modification involving the installation of new fans and ventilation dampers for the emergency diesel generator (EDG) control rooms.
The modification was requested by MR 86-1389 and was being implemented in accordance with MWO-R138033. The additional ventilation capability was requested in order-to provide assurance that the EDG control rooms would be maintained less than the-104*F temperature limitation contained in the RBS'
Technical Specifications. The modifications included the installation of new exhaust dampers on each of the EDG rooms and the replacement of the small-(3650 cfm) exhaust fans for the Division 1 and Division 2 EDGs with 15,000 cfm fans..
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.The inspector reviewed the electrical, mechanical, and structural portions of the MWO and'found the instructions for installing the modifications to be
acceptable.-
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The' inspector _ witnessed archor bolt installation and. testing, suppet bracket W,
. welding, duct work assembly, base plate grout preparation and component support
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installation activities. These activities were all conducted in-acenrdance
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' with the approved MWO and facility procedures. -. The inspector also verified that the welders' qualifications were certified and that the weld filler material and the structural steel were-being controlled.
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- The, inspector foun_d thesej1nstallation activities to be acceptable. The Linspector-did note,>however, that nine FCNs had been issued for MR 86-1389 and
- thitithree additional-FCNs,wereL in the approval = process. The FCNs were being
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controlled and~ approved in accordance with facility procedures but the need for frequentchanges!(insomecaseschangingapreviouschange)mayindicatealack
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- of attention to detail'during the engineering _ activities associated with
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modification.
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I 5. B IT. INTERVIEW I
The inspectorf sunnarized the scope and findings'of the inspection during the
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'exittinterview on 0ctober/12,_1990, with the personnel identified in.
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R cparagraphil. ' The licensee did not identify as proprietary any of the material-
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c provided to,:or reviewed by, the: inspector during this inspection.
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