IR 05000498/1989042
| ML20011D747 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 12/14/1989 |
| From: | Holler E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20011D746 | List: |
| References | |
| 50-498-89-42, 50-499-89-42, NUDOCS 8912280352 | |
| Download: ML20011D747 (10) | |
Text
_-_
._-
__
..
..
..
.
[
APPENDIX
'
U.S. NUCLEAR REGULATORY CO>NISSION
REGION IV
j NRC Inspection Report:
50-498/89-42 Operating License: NPF-76 50-499/89-42 NPF-80 Dockets:
50-490
,
50-499
!
Licensee: HoustonLighting&PowerCompany(HLSP)
.
P.O. Box 1700 l
Houston, Texas 77001
'
Fecility Name: South Texas Project (STP), Units 1 and 2 Inspection At:
STP, Matagorda County, Texas Inspection Conducted:
November 1-30, 1989 Inspectors:
J. I. Tapia, Senior Resident Inspector. Project Section D. Division of Reactor Projects J. E. Bess, Senior Resident Inspector, Project
Section D. Division of Reactor Projects
R. J. Evans, Resident Inspector, Project Section D Division of Reactor Projects
,
/
/
Approved:
'
-
E. N Holler, Chief, Project Section D Date i
Division of Reactor Projects inspection Summary inspection Conducted November 1-30, 1989 (Report 50-498/89-42; 50-499/89-42)
!
Areas Inspected:
Routine, unannounced inspection included plant status, onsite l
followup of events at operating power reactors, monthly maintenance
>
j observations, monthly surveillance observations, and operational safety verification.
'
Results: Within the areas inspected, no violations were identified. Near the
'
close of this inspection period, the Unit 2 No. 22 emergency diesel generator partially disassembled during a 24-hour load test. Review of the licensee's l
investigative and recovery actions will be addressed in Special Inspection Report 50-499/89-46 (paragraph 3).
General housekeeping, with some exceptions, l
'
89122003D2 091210 ADOCK ODOOg90 DR
__..
..
.
.
.
-2-i had improved since the last inspection (paragraphs 4 and 6). Minor discrepancies between equiprent labels and procedure nomenclature were
.
identified as in previous inspections. However, positive results regarding the Unit 2 (paragraphs 4, gram to correct these discrepancies were observed in licensee's ongoing pros and 6). The licensee's operation of the DC distribution systems appeared appropriate for safe operation (paragraph 6).
Review of the preliminary results from the eddy current inspection of Unit 2 bottom mounted instrumentation thimble tubes indicates that modifications made
!
to the thirble tubes may have minimized the problem of thimble tube wall thickness loss (paragraph 6).
..
. -.,
--
-
. _.
-
-
-.
-
_ _.- - - - _ _ - - - _ _ _ _ - _ _ _ - _ _ - - _.. _ _ _ _
-
..
..
.
.
.
-S-
,
,
DETAILS
\\
t 1.
Persons Contacted
'
'W. H. Kinsey, Plant Manager
- C. A. Ayala, Supervising Licensing Engineer i
'A. K. Khosla, Senior Licensing Engineer
'
i
- R. A. Gangluff, Chemical Operations & Analysis Manager
- M. R. Wisenburg, Chairman, Nuclear Safety Review Board
- S. L. Rosen, Vice President, Nuclear Engineer and Construction
.
- R. W. Chewning Vice President, Nuclear Operations
- W. D. Wood, General Supervisor, Radiation Protection
.
'
- H. W. Bergendahl, Health Physics Manager
- J. R. Lovell Technical Services Manager i
- T. J. Jordan, Manager, Plant Engineer
- A. C. McIntyre, Manager, Support Engineer L
- G. Parkey, Manager, Integrated Planning & Scheduling In addition to the above, the inspectors also held discussions with
!
various licensee, architect engineer (AE), maintenance, and other i
contractor personnel during this inspection.
,
i
- Denotes those individuals attending the exit interview conducted on December 1, 1989.
2.
Plant Status Unit 1 began this inspection period at 96 percent reactor thermal power.
l The unit was maintained at this power level because the No.13 main feedwater pump was out of service. After repairs to the pump were l
completed, Unit I was brought to 100 percent reactor thermal power on l
November 4,1989. The unit remained at 100 percent reactor thermal power l
level through the close of the inspection period.
Unit 2 began this inspection period at 100 percent reactor thennal power.
,
On November 3,1989, a shutdown was comenced for a scheduled reactor
!
'
vessel bottom mounted instrumentation (BMI) measurement and low pressure
!
turbine inspection outage.
Unit 2 entered Mode 5 on November 5,1989, and remained there through the close of the inspection period.
l 3.
Onsite Followup of Events at Operating Power Reactors (93702_)
i On November 19.-1989, at 1:56 a.m. (CST), Unit 1 declared a Notification
'
l of Unusual Event (NOVE) because of entering a Technical Specifications (TS)
l required shutdown condition. TS 3.7.4 requires three Essential Cooling
Water (EW) trains to be operable in operational Modes 1 through 4 (Unit 1 l
wasinMode1).
One train can be inoperable for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before plant shutdown within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is required.
On November 16, 1989, Train A of the EW system was placed out of service for routine preventive
,
j maintenance.
During that time, the self cleaning strainer motor was
,.
l
-
_
.
.
,
_
, _.
_
_ _
_
..
..
.
.
.
.
detemined to be inoperable because of nonconfoming conditions.
Sper.ifically, the motor wire insulation of the strainer was broken and a wire bend radius discrepancy existed. Because of the nonconfomances, the strainer, and therefore, the EW train were not returned to service by 1:56 a.m. on November 19, 1989, the TS 3.7.4 limiting condition for operation (LCO) 72-hour time limit.
Operations personnel prepared to shut the unit down and entered the STP Emergency Plan because of the TS required shutdown.
State of Texas, county, and NRC officials were notified. The strainer motor was returned to service at 3:23 a.m. on November 19, 1989, and the NOUE and TS 3.7.4 LC0 were exited. The themal power level of the reactor remained at 100 percent throughout the NOVE.
On November 28, 1989, at 9:57 a.m., the Unit 2 No. 22 emergency diesel generator failed after approximately 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> of a planned 24-hour load test. The diesel had perfomed normally for the first 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> of the run and digsel parameters, which were being recorded hourly, showed no out of specification readings. At the time of the failure, two instrumentation and control (I&C) technicians who were working near the diesel heard an unusual sound and exited the diesel room.
Subsequent investigation disclosed various diesel parts on the diesel room floor in the vicinity of the No. 4 cylinder. Specifically, a crank-case ins embedded in a piece of machinery (starting air dryer) pection cover was approximately 5 feet opposite the No. 4 cylinder, and the No. 4 pistons and articulated connecting rod were laying on the floor near the diesel. There was no personnel injury, fire, or explosion associated with the failure.
Preliminary investigation indicated that the No. 4 connecting rod assembly failed. The licensee initiated an investigation to detemine the specific cause of the failure. After initial response by the Senior Resident inspector, both regional and NRR diesel experts arrived on site on November 30, 1989.
Investigative and recovery actions were continuing at the end of this inspection period. The results of the region review of this matter will be addressed in Special Inspection Report 50-499/89-46.
As a result of finding cracks in the Unit 1 stationary low pressure turbine blades during the unit's first refueling outage, the licensee initiated an inspection of the Unit 2 low pressure turbines during the ongoing Unit 2 BMI outage. The inspectors reviewed the results of the licensee's nondestructive examination (NDE) and repair activities. All bladeswereexaminedusingthedye-penetrant (PT)methodofinspection.
One hundred and five indications on 89 blades were found in Low-pressure Turbine No.1, 54 indications on 50 blades in Low-pressure Turbine No. 2, and 70 indications on 66 blades in Low-pressure Turbine No. 3.
Westinghouse personnel perfomed the NDE and identified the findings.
All indications were identified as valid indications and potential initiators for a crack.
Each indication was then examined to detemine if it was a manufacturing defect or flaw, or if it was the result of resonance fatigue as was the case in Unit 1.
If an indication was identified as a
" crater-crack" manufacturing flaw which occurred during the original welding process, it was repaired by. blending out the indication, i
_
-
.- -.--
_ _ -
- - -.--
_.
.
..
.
i
-
.
.
i I-5-
i Indications larger than 1/4 inch were considered to be the result of resonance fatigue and were ground out and repaired by welding.
The ground
!
out and blended areas were PT inspected to verify that the cracks or defects had been removed.
These repairs addressed the resonance fatigue
cracking concerns identified during the Unit I refueling outage.
i No violations or deviations were identified in this area of the inspection.
4.
Monthly Maintenance Observations (62703)
,
The inspector observed selected maintenance activities to verify whether the activities were being conducted in accordance with approved procedures and TS. The activities observed included:
.
PaventiveMaintenance(PM)IC-0-EM-89004152, Meteorological
Monitoring System Biweekly PM Work Request (WR) EW-87362. Replacement of Essential Cooling Water
'
Pump 2A upper and lower motor bearings Incorporation of Nonconfomance Report (NCR) 89-2-233 Reworking
metal cover plates on junction boxes The inspectors verified that the activities were conducted in accordance with approved work instructions and procedures, test equipment was within
'
its current calibration cycle, and housekeeping was being maintained in an acceptable manner.
The following items were observed and discussed with licensee representatives for appropriate action:
..
The licensee performed PM IC-0-EM-89004152 on both the Primary and Backup Meteorological Monitoring System (MET) Towers. The biweekly PM includes changing recorder chart paper and magnetic tapes.
The Backup Met Tower digital clock was observed to be 10 minutes fast.
Some trash was observed
-
in the Primary and Backup Het Tower buildings, but general housekeeping had improved since the last inspection.
The licensee wrote work request (WR) EW-87362 to replace the upper and lower motor bearings of the EW Pump 2A, The bearing replacement was
'
required because excessive vibration was observed during a previous uncoupled motor run.
The inspector observed disconnection of the motor leads, licensee inspection of old bearings and reconnection of the motor leads. No concerns were identified.
-
'
The licensee wrote nonconfomance report (NCR) 89-2-233 to rework the 12 metal cover plates on the cathodic protection junction boxes located in the EW intake. The work included replacing missing or corroded bolts, drilling out the bolt holes, and adding caution signs to the cover of the boxes. The inspectors performed a followup inspection to verify that housekeeping was maintained.
All covers and bolts were noted to be in
'
place, however, several caution signs were missing.
.-
-
-..
-.
-.
i
..
'
.
.
l-6-No violations or deviations were identified in this area of the inspection.
5.
Monthly Surveillance Observations (61726)
Selected surveillance activities were observed to ascertain whether the surveillance of safety significant systems and components were being conducted in accordance with TS and other procedural requirements. The activities observed included:
Procedure 2 PSP 06-DJ-0001, "125 Volt Class 1E Battery 7 Day Surveillance Test," Revision 1
Procedure 2 PSP 06-NZ-0001, "13.8KV Relay Channel Calibration,"
Revision 2
Procedure 2 PSP 02-RC-0458, " Pressurizer Pressure Set 4 ACOT,"
Revision 0
Procedure 2 PSP 05-FW-0572, " Steam Generator 28 Narrow Range Level Set 1 Calibration (L-0572)," Revision 0 Specific items inspected included verifying that as-left data was within acceptance criteria limits, the acceptance criteria listed in the procedures agreed with values listed in design documents, and test equipment used was within its current calibration cycle.
Following observation of the surveillance activities, the procedures were reviewed for technical accuracy and conformance to TS requirements. All items observed were discussed with the licensee for appropriate action.
Procedure 2 PSP 06-DJ-0001 was perfomed by electrical technicians on Class 1E Battery E2A11. The procedure provided instructions on performance of the weekly TS required battery surveillance. Step 6.10 of the procedure (recording battery charger output current and voltage) was performed out of sequence by the technicians. The procedure did not specify the sequence for perfoming the steps and no adverse results from perfoming the steps out of sequence were apparent.
Because four out of six room light bulbs were burned out, the use of flashlights was necessary during the test when inspecting the general appearance of each battery cell. Step 6.4.2 provided instructions to perform a terminal connection resistance check if corrosion was found on a terminal connection.
Indications of corrosion were found on the bar of Battery Cell No. 44, but a resistance check was not performed. The technicians determined that the connection was not corroded, therefore, the check was not required. The bar of Battery Cell No. 44 and two other bars were subsequently cleaned and greased.
Procedure 2 PSP 06-NZ-0001 was perfomed by electrical technicians on 13.8KV Switchgear 2G relays. The procedure provided instructions for performing 18-month surveillances on 13.8KV electrical penetration overcurrent protective relays. No specific concerns were identified during the perfomance of the surveillance.
l
)
..
'
.
.
~7-Procedure 2 PSP 02-RC-0458 was performed by I&C technicians on Train C pressurizer pressure high/ low trip circuitry. The procedure verified that the trip setpoints were within acceptance criteria limits.
Several minor labelling discrepancies were observed.
For example, Plant Computer Point PD0482 was referred to as PRZR CH 4 PRESS in the procedure but actually was labelled as PRZR CH IV PRESS. During perfomance of Steps 7.6.12 and 13 (recording the as-left data), the digital multimeter (DM) failed to operate. The DMM was on battery power and apparently the battery power was too low to support DMM operation. The meter was connected to AC power and the steps were perfomed.
Procedure 2 PSP 05-FW-0572 was perforned by IAC technicians on the Steam Generator 2B Level H1/Lo trip setpoints. The procedure verified that the instrument loop was within calibration limits. Asterisks (*) were used to identify steps that required a sign off in the data package.
Step 6.3 was missing (QDPS) computer points were listed differently in the procedure its required asterisk.
Four Qualified Display Processing System than on the display screens.
For example, Point FWLA0572 was listed as LT572 on the display screen.
Instrument Loop A2FW-L-0572, Revision 1, "SG 2B Narrow Range Level," in the procedure listed two computer points with the same identification number (FWLA0572).
No violations or devistions were identified in this area of the inspection.
6.
Operational Safety Verification (71707)
The purpose of this inspection was to ensure that the facility was being operated safely and in conformance with license and regulatory requirements. This inspection also included verifying that selected activities of the licensee's radiological protection program were being implemented in conformance with requirements and procedures, and that the licensee was in comp 11anc.e with its approved physical security plan.
The inspectors visited the control rooms on a. daily basis when onsite and verified that control room staffing, operator. decorum, shift turnover, adherence to TS LCOs, and overall control room decorum were in accordance with requirements. The inspectors conducted tours in various locations of the plant to observe work and operations and to ensure that the facility was being operated safely and in confonnance with license and regulatory requirements.
The Class 1E Engineered Safety Feature (ESF) Direct Current (DC)
Distribution systems were inspected to verify the operability and status of the systems. Both the Unit 1 and Unit 2 DC Distribution systems were inspected. The inspection included comparison of as-found switch and breaker positions to positions required by the operating procedures, and a comparison of the operating procedures to design documents. The.
procedures reviewed and walked down included:
l I
,
.
-
-
. -. - _
_
-
-
.
- _ _
. _ _
_ -. ___
-
..
c i
!
.
o
'
!
-S-
IPOP02-EE-0001 ESF (Class IE) DC Distribution System Revision 4
2 POP 02-EE-0001, ESF (Class IE) DC Distribution System. Revision 1
,
IPOP02-EE-0001 established the guidelines for operating the Unit 1
safety-related DC Distribution system.
The procedure described the steps necessary to place the system in an operable status, including placing
.
battery chargers in service and alignment of DC breakers.
l Step 1.2.4 of the purpose and scope section stated, "This procedure
<
covers:
perfoming an equalizing charge on the battery." The procedure l
did not describe how to perform an equalizing charge, but referred to
,
another procedure. Labelling discrepancier were observed.
For example.
l the Incoming Line From Battery Breaker No. I was referred to as, " Battery
Output Input Breaker #1" in Step 7.2.
Typographical errors were observed.
,
to step)ple, Breaker Position T3R was called T3B in Steps 6.1 (note ptior
'
For exam and 6.4.
These items were noted and referred to the licensee for appropriate action.
-.
,
2 POP 02-EE-0001 established the guidelines for operating the Unit 2 safety-related DC distribution system.
Battery Chargers E2B11-1 and E2B11-2 were inarked with hand written labels that read, " Equalize OFF-ON."
The labels indicated incorrect positions for the equalize float toggle
switch. Typographical errors similar to those found in the Unit 1
.
procedure were found in the Unit 2 procedure (Breaker Position T3R versus
,
T3B).
Numerous labelling discrepancies were observed. For example,
'
several Unit 2 components had labels on the equipment that used Unit I designators instead of Unit 2 designators. These following items were
'
noted and referred to the licensee for appropriate action.
.
As part of the overall procedure enhancement program and resolution of labelling discrepancies, the licensee was in the process of changing out Unit 2 labels. The new labels are larger and easier to read.
The labels
,
i identified as incorrect were old labels that were in the process of being
'
removed and replaced.
In conclusion, all switches, breakers, and power
,
supplies were found in the correct positions. The DC distribution systems were found to be in a condition that supported plant operations.
The routine inspection tours conducted in both Unit I and Unit 2 included observations regarding general housekeeping.and condition of equipment.
No potential fire hazards were identified and no improperly secured compressed gas cylinders were observed. The following (etails were
,
observed and referred to the licensee for appropriate action.
Nonsafety-related panel housing feedwater Instruments FW-LT-71750 and-
-
FW-LT-4012 had signs on the panel that stated:
(1)RestoreAll Fasteners Upon Closure of Equipment, (2) Warning, Authorized Entry-Only, (3) Caution, Sensitive Instruments, and (4) This Cabinet Not to be Used for Storage of Materials. Tools, or Personal Items.
-
Notwithstanding these labels, the panel door was found open, and a
,
tube of lubricant and 24" pipe wrench were found inside. The panel was located outdoors on the Unit I turbine operating deck.
i
,..
~. _., ~
,
-
,
,
-
,
_
_. -
-
--
.
-
.
.
.-.
_- - -
-
..
_
..
.
'
.
.
!
.
-9-
,
[
I The floor of Room 357 in the Unit 2 Mechanical Auxiliary
!
Building (MAB) was noted to be unusually dirty.
Items observed on
'
the floor included a small oil spill, paper, pieces of wire, sawdust, and ty-raps. With the noted exceptions. MAB was found to be
,
'
generally clean.
,
An inspection tour of the Unit 2 Reactor Containment Building (RCB)
was performed. Housekeeping was being maintained in most areas of
the RCB. An exception was an area near the personnel access hatch, where contaminated and uncontaminated equipment was stored. Three radiation boundary signs were found on the floor of the RCB. The
,
locations were: at doors to Room 304 (Residual Heat Removal Heat
~
Exchanger 2A) and Poom 201 (biological shield entry point) and at a shield wall hole near the Safety Injection System Accumulator Tank 2A. These items were referred to the on-shift health physics technician for appropriate action.
The eddy current inspection of the BMI thimble tubes was completed during the Unit 2 outage.
BMI thimble tubes extend through the bottom of Westinghouse pressurized water reactor vessels into selected fuel assemblies and are used to hold incore neutron detectors. They also constitute part of the reactor coolant system pressure boundary. The NRC staff advised utilities early in 1988 that thimble tubes were experiencing wall thinning as a result of flow-induced vibration and that there had been several instances of thimble tubes leaking as the result of this wall thinning. The l
,
licensee made modifications to the BMI thinble tubes in Unit 2 during
construction of the unit. These modifications included removal of
the flow limiting devices and installation of thicker wall thinble tubes. Westinghouse inspected each of the 58 thimble tubes along its i
entire length. No detectable defects were found. The sensitivity of
,
the inspection technique and analysis was such that only defects greater than 10 percent wall loss were reported as detectable.
Each
,
thimble tube has a 0.385-inch outside diameter. Unit 2 has had an
>
operating time of 32 weeks and 2 days.
In comparison, the first BMI l
inspection for Unit 1 after 16 weeks of operation showed that l
!
19 thimble tubes had wall thinning ranging from 12 to 60 percent of wall thickness for the old design thimbles (0.313-inch outside diameter).
These results indicated that the modification to increase the thimble tube wall thickness has minimized the problem of thimble tube well thickness loss. Modifications to the Unit I thimble tubes, including installation of the thicker wall tubes, were completed during the Unit I refueling outage from August to October 1989.
,
'
!
No violations or deviations were identified in this area of the
!
inspection.
7.
Exit Interview (30703)
l The NRC inspectors met with licensee representatives (denoted in
paragraph 1) on December 1,1989. The NRC inspectors summarized the scope l
.-
.-
.
_
_
_
._
.-
..
..
o
.< o-10-and findings of the inspection. The licensee did not identify as proprietary any of the information provided to, or reviewed by, the NRC inspectors.
l i