IR 05000285/1994002
| ML20059L479 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 01/27/1994 |
| From: | Powers D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20059L468 | List: |
| References | |
| 50-285-94-02, 50-285-94-2, NUDOCS 9402070047 | |
| Download: ML20059L479 (9) | |
Text
..
.
APPENDIX U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
Inspection Report:
50-285/94-02 License: DPR-40 Licensee: Omaha Public Power District Fort Calhoun Station FC-2-4 Adm.
P.O. Box 399, Hwy. 75 - North of Fort Calhoun Fort Calhoun, Nebraska Facility Name:
Fort Calhoun Station Inspection At:
Blair, Nebraska Inspection Conducted: January 3-7, 1994 Inspectors:
L. Gilbert, Reactor Inspector Maintenance Section Division of Reactor Safety C. Johnson, Reactor Inspector Maintenance Section Division of Reactor Safety W
'/#7/4Y Approved:
Dr. Dale Powers, Chief, Maintenance Section Date Division of Reactor Safety Inspection Summary
-
Areas Inspected:
Routine, announced inspection of erosion / corrosion monitoring program and associated activities.
Results:
.
The licensee had developed an upgraded program for the detection of
component degradation in high-energy piping resulting from erosion /
corrosion that adequately addressed the concerns identified in Generic Letter 89-08 (Section 2.1.1).
The responsible engineer was well trained and knowledgeable of the
=
erosion / corrosion program (Section 2.1.1).
9402070047 940128 PDR ADOCK 05000285 G
,
,
-.
.,. -.
-
.
-
.
- q
.
l
?
.
!
.
t-2-'
j
The licensee had partially upgraded the program 'to include CHECMATE
.
,
computer modeling of each susceptible-system (Section 2.1.1).
.7 The licensee's erosion / corrosion program had been thoroughly reviewed by-
.
an independent consulting firm (Section 2.1.3).
'
-!
i The procedures clearly defined responsibilities for the erosion /
l
.
corrosion program (Section 2.1.4).
'
The licensee properly evaluated and satisfactorily dispositioned
.
components with unacceptable thicknesses (Section 2.1.5).
}
Personnel who performed thickness measurements were appropriately
=
certified as qualified, and equipment utilized was calibrated'(Section
,
2.1.6).
"
Summary of Inspection Findinas:
'
No inspection findings were opened or closed.
.
I Attachment:
Attachment - Persons Contacted and Exit Meeting
=
,
,1
,
,
?
i
<
i
.
..
-
-.
- - - - - - -
I
.
.
-3-DETAILS 1 PLANT STATUS During this inspection period, the plant was operating at power.
2 INSPECTION OF EROSION / CORROSION MONITORING PROGRAMS (49001)
The objectives of this inspection were to ascertain whether (a) licensee activities relative to the long-term erosion / corrosion monitoring program were in accordance with Generic Letter 89-08, " Erosion / Corrosion-Induced Pipe Wall Thinning"; (b) management control problems or weaknesses existed in the implementation of the program; and (c) the program had been independently reviewed.
2.1 Discussion 2.1.1 Program Development The inspectors reviewed the licensee's response to Generic Letter 89-08. The response was documented in a letter to NRC dated July 20, 1989. The licensee notified the NRC in this letter that an erosion / corrosion control program was in place. The program was used for the inspection and evaluation of 188 piping components during the 1987 refueling outage and 104 components during the.1988 outage.
The components selected in 1987 were based on engineering.
judgement and industry experience, whereas the selection of components in 1988 included the 10 most susceptible components in single-phase piping systems bead on analytical results using the Electric Power Research Institute (EPRI)
CHEC computer program.
In addition, the licensee specified that a long-term erosion / corrosion control program based on the Nuclear Utility Management and Resources Council criteria was scheduled to be in place before the 1990 refueling outage.
The inspectors were informed that the licensee's erosion / corrosion program included the following documents.
Program Basis Document that contained historical background information,
outage planning activities, methodologies and strategies, and summaries of each outage; Technical Reference Manual that contained the basis for the computer
modeling of single and two-phase piping systems in the plant, location and designation of components on piping drawings, and general as well as chronological history of testing performed on each component in the program;
.
.-
-4-Station Procedures for engineering analyses, ultrasonic thickness
measuring, and gridding activities; EPRI CHECMATE Computer Program analysis and related documentation; and
Outage reports that documented the erosion / corrosion program activities-
for 1987, 1988, 1990, 1992, and 1993.
Since the establishment of the.long-term program in 1990, the licensee had implemented program enhancements in the areas of piping component gridding, inspection equipment, and selection of components. -Improvements in the.
gridding of components included the use of. heat-resistant marking materials'
(for establishing permanent markings) and photographing the components after gridding (for repeatability and comparison of future thickness measurement data). The ultrasonic thickness measuring equipment used for performing the
'
wall thickness measurements on piping components was upgraded to the latest
,
state-of-the-art technology during the last outage.
The selection of components for the last outage inspections was modified to incorporate the component wear predictions.obtained from the CHECMATE computer modeling
,
effort, which was performed prior to the 1993 outage by the licensee. This effort analyzed one train of each piping system determined to be susceptible to erosion / corrosion.
Further enhancement of the program was expected, as.a result of the licensee's continued programmatic-approach to analyzing inspection results and continued association with other utilities through the
~
CHEC/CHECMATE Users Group (CHUG) and the complete modeling of the systems using the new CHECWORKS program. The licensee informed the inspectors that l
the CHECWORKS effort should be completed prior to the next scheduled refueling
'
outage.
The inspectors concluded that the licensee had developed an upgraded
'
program for the detection of component degradation in high-energy piping resulting from erosion / corrosion that adequately addressed the concerns
,
identified in Generic Letter 89-08.
The inspectors were informed that the responsible engineer and'several other i
engineers had been trained by EPRI personnel on the CHECMATE computer program.
(
Furthermore, the responsible engineer and his backup were scheduled to receive extensive training from EPRI personnel on the new CHECWORKS program for more
,
complete modeling of the piping systems. The inspectors interviewed the
,
responsible engineer and concluded that the responsible engineer was well
+
trained and knowledgeable of the erosion / corrosion program.
,
,
2.1.2 Review of Dat'a Input for CHECKMATE Modeling r
The inspectors selected for review four piping systems that were. identified as
.'
being potentially susceptible to erosion / corrosion: main feedwater, steam-generator blowdown, high-pressure turbine extraction steam, and'feedwater
,
heater drains. The CHECMATE input data was reviewed for the following i
segments of piping.
i I
-
- _ - -.
-_
_
-.
.
.
-5-Feedwater line from the containment penetration to Steam Generator
RC-2A; Blowdown line from Steam Generator RC-2A to the containment penetration;
Extraction steam line from the second stage, high-pressure turbine to
Feedwater Heater 6A; and Heater drain line from Feedwater Heater 148 to Heater Drain Tank FW-17.
- The inspectors were informed that the licensee used the " Procedure Section" of Volume 1 of the CHECMATE Program Manual as guidance.
The input and modeling work was performed by Design Engineering and independently reviewed by Special Services Engineering.
The Fort Calhoun Station model used 3 files for the 16 cases. A single file was defined as a data base with no more than 6 cases, 10 segments per case, and 50 components per segment with a maximum of 3000 components per file. A case consisted of piping with the same system fluid chemistry history, and a segment was a group of components with the same design pressure and temperature within a case. The input data from these cases was shown in numeric order in Volumes 1 and 2 of the CHECMATE Program Manual. Volume 3 of the CHECMATE Program Manual contained the marked up isometrics with geometrically coded CHECMATE components. The inspectors verified that all piping components for the portion of the four systems reviewed had been entered into the CHECMATE computer program, including elbows,: tees, valves, and straight pipe. The inspectors used the licensee's piping and isometric drawings; National Valve and Manufacturing Company piping catalog; full-power, heat-balance diagram; and the CHECMATE Computer Prograu User's Manual to verify piping component data input.
I'
for each of the piping segments selected above, the inspectors compared the
,
l engineering input data and local operating conditions to the database in the licensee's computer program. The database parameters reviewed included the pipe size, schedule, length, material, geometry factors, and operating
.
conditions including flow rate, water chemistry, temperature, pressure, and I
hours of operation.
Engineering had derived the CHECMATE input database from
'
the piping isometric drawings, the heat-balance diagram, the CHECMATE User's Manual, and information provided by operations and chemistry.
The inspectors identified three areas where the database parameters were not'
consistent with the piping isometric drawing and. heat-balance diagram. 'The first anomaly consisted of an incorrectly specified pipe schedule for an
. extraction steam line (Schedule 80 was used instead of Schedule 40). The-other two anomalies were identified in the database parameters specified for the feedwater and blowdown lines (the enthalpy of the water was.specified as 1169.9 and 1197.9 Btu /Lb when the values should have been 424 and 520 Btu /Lb, respectively).
In response to the inspectors' findings, the licensee corrected the input data and performed a new CHECMATE analysis. Although the new analysis predicte :
,
.
!
.
-6-
.
increased wear for most components, the components of concern had either been replaced during previous outages or inspection data from previous outages showed actual wear rates to be much less in these lines; therefore, the components selected for examination during the last outage would not have been-
!
influenced by the new CHECMATE predictions.
With exception of these anomalies, the licensee's-erosion / corrosion input data was well documented.
Piping and isometric drawings were marked up_for easy reference. The final results and output data was compiled into book binders.
,
Input data forms and engineering judgments were well documented.
Engineering judgments related to such things as flow rate, insulation, pressure, and
',
enthalpy.
The licensee's overall effort in the compilation of data and documentation of the systems reviewed was excellent.
!
2.1.3 Independent Audit Results I
The inspectors were informed that an outside engineering consulting firm, ABB Impell Corporation, was also contracted to perform an independent review of -
.
the licensee's CHECMATE modeling effort and erosion / corrosion control program.
'
The results of this independent review were documented in a letter dated.
,
December 7, 1993. The licensee stated that these results were not received in
,
time to be incorporated into the program and selection of components examined during the 1993 outage. The letter from the consulting firm acknowledged that no major errors were identified during review of the CHECMATE model; the.
planned upgrade to CHECWORKS would provide an opportunity to incorporate the
,
minor data input errors that were identified, as well as, other comments made on the CHECMATE model.
The inspectors reviewed the letter and the a sample _ of the comments and concluded that a thorough effort had been performed by the independent reviewers.
'i 2.1.4 Procedure Review The inspectors reviewed the licensee's procedures pertaining to the erosion / corrosion program.
The procedures clearly defined responsibilities for the erosion / corrosion monitoring program. The three main procedures
-
utilized at Fort Calhoun Station were the following:
PM-PIPE-1, " Ultrasonic Inspection Of Station Piping," Revision 4, dated
September 23, 1993;
'
e QCP-331, " Ultrasonic Thickness Measurement For Erosion / Corrosion,"
Revision 5, dated October 8, 1993; and QCP-332, " Gridding Procedure For Erosion / Corrosion," Revision 6, dated
October 8, 1993.
-t The procedures contained specific requirements and general guidance pertaining
'
to the systems to be inspected, inspection location guidelines, acceptance and-rejection criteria, responsibilities, ultrasonic instrumentation, surface
.
>
'
...
-
y
i
!
-7-l
,
preparation, examination of results, calibration of ultrasonic equipment, gridding, evaluation of results, establishing examination locations, and report documentation.
No problems were identified during the review of the
procedures that governed the erosiaa/ corrosion program.
j 2.1.5 Sample Review of Inspection Activities
[
In order to review the implementation of the erosion / corrosion monitoring
'
program, the. inspectors selected a number of inspection activities _from four piping systems: main feedwater, steam generator blowdown, high-pressure extraction steam, and high-pressure heater drains.
For'each of the
,
activities, the inspectors reviewed the thickness measurement reports and engineering evaluations. The minimum _ measured thickness for_each component'
was reviewed against the criteria established by engineering.
For the samples
selected, the inspectors verified that the results had been evaluated and
satisfactorily dispositioned by engineering.
For those_ components that exhibited wall-thickness degradation, the inspectors verified that the
!
components had been replaced or scheduled for an examination within the _
l specified number of refueling cycles in accordance with criteria established
,
by engineering in Procedure PM-PIPE-1..The inspectors noted that the Nuclear
'
Safety Review Group reviewed the results obtained from monitoring piping thickness and verified engineering calculations performed on piping components
't accepted for continued service.
y 2.1.6 Personnel Qualifications / Equipment Calibration The inspectors reviewed personnel qualifications and certifications for the
'
personnel conducting the non-destructive examinations. Records indicated that NDE personnel were qualified and certified to perform the non-destructive examination thickness measurements that were made.
Non-destructive examination personnel were qualified in accordance with site Procedure QC0-200, " Certification Requirements For Quality Control Inspectors," Revision 8, and Recommended Practice No. SNT-TC-1A, " Personnel Qualification and
i Certification in Nondestructive Testing," June 1980 Edition.
Examination to verify physical and technical qualifications were included in the personnel files reviewed by the inspectors.
,
I The inspectors also reviewed the ultrasonic equipment calibration records and verified that equipment was within calibration and calibrated against known >
,
standards for the range of thicknesses to be measured.
No deficiencies were identified during this review.
,
'
2.2 Conclusions
!
The licensee had developed an upgraded program for the detection of component degradation in high-energy piping resulting from erosion / corrosion that
adequately addressed'the concerns identified in Generic Letter 89-08.
The
!
licensee had partially completed upgrading the program to include CHECMATE computer modeling of one train of each susceptible system. The responsible
engineer was well trained and knowledgeable of the erosion / corrosion program.
)
'I
'
.
.-
,
.
-8-The licensee's input data into the CHECMATE computer program was well documented.
Data input was in accordance with EPRI CHECMATE guidelines.
Even though some errors were identified by the inspectors and the independent auditors, the overall analytical effort was excellent.
The few" errors identified were corrected during the inspection and satisfactorily evaluated by the licensee.
Input data and engineering judgments.were well documented.
The program procedures clearly defined responsibilities for developing, maintaining, and implementing the erosion / corrosion program.
The licensee's erosion / corrosion program had been thoroughly reviewed by an independent consulting firm.
Personnel performing the thickness measurements were qualified and certified i
to perform the accomplished work activities. Ultrasonic equipment used was l
verified to be within calibration and calibrated to known thickness standards
!
during the periods of use.
t The inspection did not identify any management control problems or weaknesses
'
in the implementation of the program.
For those sampled components with a
,
measured thickness less than the specified acceptable thickness, the licensee properly evaluated and satisfactorily dispositioned those results.
.
-.
,
i k
i
{
.-
'4 ATTACHMENT 1 PERSONS CONTACTED 1.1 Licensee Personnel R. Andrews, Division Manager, Nuclear Services C. Bloyd, Lead Engineer, Special Services Engineering C. Boughter, Supervisor, Special Services Engineering J. Chase, Plant Manager G. Cook, Supervisor, Station Licensing J. Gasper, Manager, Training R. Jaworski, Manager, Station Engineering L. Kusek, Manager, Nuclear Safety Review B. Lisowyz, Senior Design Engineer W. Orr, Manager, Quality Assurance / Quality Control T. Patterson, Division Manager, Nuclear Operations R. Phelps, Acting Division Manager, Production Engineering D. Rollins, Special Services Engineer R. Short, Manager, Nuclear Licensing J. Skiles, Acting Manager, Design Engineering
.
l2 NRC Personnel R. Azua, Resident Inspector The personnel listed above attended the exit meeting.
In addition to the personnel listed above, the inspectors contacted other personnel during this inspection period.
2 EXIT MEETING An exit meeting was conducted on January 7, 1994. During this meeting, the inspectors reviewed the scope and findings of the report. The licensee's management expressed a position that they were in agreement with the inspection findings documented in this report.
The licensee did not identify as proprietary any information provided to, or reviewed by, the inspectors,
,