IR 05000397/1992010
| ML17289A521 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 04/23/1992 |
| From: | Narbut P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17289A520 | List: |
| References | |
| 50-397-92-10, NUDOCS 9205110052 | |
| Download: ML17289A521 (14) | |
Text
Report Number:
License Number:
Licensee:
Facility Name:
U.S.
NUCLEAR REGULATORY COMMISSION
REGION V
50-397/92-10 NPF-21 Washington Public Power Supply System P.O.
Box 968 3000 George Washington Way Richland, Washington 99352 Washington Nuclear Project No.
(WNP-2)
Inspection Conducted:
March 23 through 27, 1992 Inspector:
Michael J.
Royack, Reactor Inspector RV Approved By:
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9 A routine, announced inspection was conducted of the licensee's erosion/corrosion program activities.
NRC inspection procedure 49001,
"Inspection of Erosion/Corrosion Monitoring Programs,"
and associated documents were used as guidance for this inspection.
ts:
The licensee's erosion/corrosion program was in effect prior to commercial operation of WNP-2.
The program has utilized two predictive computer programs, the EPRI CHEC code and the Keller Equation, to determine erosion/corrosion rates and areas of high probability for erosion/corrosion in piping components.
This process appeared to have successfully identified potential areas which are susceptible to erosion/corrosion.
For these areas, testing, corrective actions and repairs have been made.
However, the program has been operating without a formalized Engineering Management Project Guideline or a clear quality assurance presence in the program.
The responsible Supply System representative stated, at the exit interview, that the Supply System would include the WNP-2 erosion/corrosion program into the programs to be formalized in accordance with the Engineering Management Project Guidelines program plan.
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The inspector concluded that the WNP-2 erosion/corrosion program had strengths in the areas of personnel continuity, inter-discipline interfaces, system erosion/corrosion modeling, incorporation of plant operating experience into the program, and personnel training.
a s
The inspector concluded that NNP-2 did not use approved written procedures to implement the erosion/corrosion program, and that the program appeared to lack clear evidence of management and quality assurance overview.
XiQl4~t No violations or deviations were identified during this inspection..
t u
na em nt S stem S
HS te s:
None.
~DO~K One follow-up item was opened during this inspectio A. Alexander, Health Physics/Chemistry Support Supervisor T. Albert, Haintenance Supervisor L. Bradford, Health Physics Planning Supervisor D. Coleman, Nuclear Safety Engineering R. Davis, Material Engineer J. Flood, Engineer G. Gelhaus, Assistant Plant Technical Hanager L. Harrold, Assistant Plant Manager A. Hosier, Licensing Hanager S.
Kim, ALARA Engineer C. King, Haterials
& Welding Supervisor C. Madden,'lant guality Assur ance Engineer L. Hauws, Plant Technical Supervisor C. McGilton, Operational Assurance Manager R. Moen, Materials 8 Inspection Manager C. Noyes, Engineering Programs Manager C. Powers, Director of Engineering R. Rana, Lead Specialty Programs M. Reis, Compliance/Technical Supervisor J.
Rhoads, Operations Events Assessment Manager D. Thompson, Special Projects Manager D. Welch, Non Destructive Examination/In Service Inspection Services Supervisor QC M. Royack, Region V Engineering Reactor Inspector
+L. Carson, Region V Health Physics Inspector
<<All listed licensee personnel attended the exit meeting on March 27, 1992.
+Indicates additional NRC staff attending exit meeting.
2.
nt oduct on 4900 The purpose of this inspection was to evaluate the licensee's long term erosion/corrosion monitoring program to determine if the program was being conducted in accordance with NRC guidelines established in Generic Letter 89-08, "Erosion/Corrosion-Induced Pipe Wall Thinning," to determine if the program was being conducted in accordance with licensee commitments and procedures, to determine if management control problems or generic weaknesses existed, and to determine if a guality Assurance (gA) or independent reviews of the program have been conducte !
3.
t on The inspector reviewed the licensee's
"Nuclear Power Plant No.
2 Pipe Mall Thinning Program Plan,"
and associated Plant Procedures manual procedure No.
8.6.63,
"Surveillance Procedure For Monitoring Pipe Wall," to determine their conformance to the licensee's commitments submitted in response to NRC Generic Letter 89-08,
"Erosion/Corrosion-Induced Pipe Mall Thinning."
The inspector reviewed the method the licensee was employing to determine erosion/corrosion rates, the piping and components to be inspected the documentation and calculations that supported the analysis, inspection data, inspection processes, inspection data feedback to the analysis group, and actions taken for items identified as needing repairs or replacements.
Items noted by the inspector during this inspection are detailed below.
'a 0 EPRI CHEC and the Keller Equation are methods used to predict erosion/corrosion rates at WNP-2.
EPRI CHEC is a computer program and the Keller Equation is a manual calculational method.
The inspector observed that the licensee had used EPRI CHEC version 1.0 to model the main feedwater and condensate systems, and was using the Keller Equation method for determining erosion/corrosion in single phase and two phase flow piping.
The licensee was committed to rejoining the CHEC/CHECKMATE users group (CHUG) to augment their present program.
Based on his review of the results of the licensee's analysis and inspection findings, the inspector concluded that the program, conservatively predicted erosion/corrosion wear rates.
The inspector also concluded that the information was being used to define and expand inspection point locations for future outages and scheduled repairs or replacement.
b.
t n
teria The inspector reviewed the licensee's system selection criteria for determining which systems would be included in the erosion/corrosion program.
He concluded that the licensee has implemented a line selection criteria which followed the guidelines contained in NRC Bulletin 87-01,
"Thinning of Pipe Walls in Nuclear Power Plants,"
The inspector reviewed system parameters for four systems that were subject to examination and four systems for those which are excluded from examination.
The inspector concluded from the sample that the selection criteria was being properly applied.
The inspector noted that the licensee's line selection criteria used pipe design temperatures instead of in service system temperatures.
The use of design temperatures was conservative.
Additionally, as a
conservative approach, after a carbon steel pipe or component was replaced with a non-carbon steel (stainless steel)
pipe or component,
that item remained in the inspection program.
However, it would be inspected less frequently.
c. Qg~i~ut The inspector reviewed heat balances, and calculations for four systems to verify that correct data was input into the Keller Equation for the ranking of lines.
The inspector concluded that the information was accurately entered into the equations, and that the results were consistent with the data provided.
d.
1 t o s Tabul t on The inspector reviewed the licensee's Keller ranking calculations and data spread sheets, and concluded that the information was accurate and verifiable.
The inspector confirmed that inspection data was included in the tabulated data, and noted that estimated wear rates were conservative compared to actual wear rates.
e.
t ns The Haterials and Inspection erosion/corrosion engineer had produced an inspection plan for each outage, listing inspection location recommendations based on the Pipe Mall Thinning Program Plan and previous inspection results.
The plan was reviewed and approved by the Plant Technical Manager.
An outage report documenting inspection results and next outage repair or replacement recommendations was prepared after each outage.
The inspector reviewed the proposed outage inspection plans for Refueling Outage R5 and R6, inspection outage reports for R5 and R6, and final spreadsheets of the results.
The inspector noted that the number of examination points for each outage appeared to be below the number of points other facilities typically examine during an outage period.
The licensee indicated that one point on the list indicated one component and on that component there could exist several inspection grids, e.g.
an elbow or a tee could have up to four grids or sample areas, therefore the actual number of inspection points could be as high as similar facilities.
The inspector confirmed that several grids were located on one examination point on Bleed Steam lines 16" BS(3)-2, point 313-2 (4 grids),
16" BS(1)-2 point, 390-2 (4 grids),
and Heater Drain line 10" HD(9)-2, point 370-2 (3 grids).
Additionally, MNP-2 was on a twelve month refueling outage cycle while some other facilities are on eighteen month refueling cycles.
Therefore, the licensee stated that the yearly average number of inspection points for WNP-2 were similar to those at a
facility on an eighteen month refueling cycle.
The inspector concluded that the number of examination points performed, on an yearly average basis by WNP-2, was consistent with the number of sample points typically examined at other facilities.
The inspector confirmed that at least one baseline inspection for all
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susceptible lines had been completed by R6, with the exception of five reactor water clean-up lines which are in high radiation areas and have been delayed for ALARA reasons.
The inspector reviewed photographs of inspection locations that are permanently scribed with inspection grids, using low stress stamps, to facilitate information trending and accuracy.
However, the inspector was unable to visually inspect exact locations due to plant operations.
f.
o a
The inspector reviewed procedure gCI 6-1 Revision 4, "Ultrasonic Examination - Thickness measurements,"
two NDE inspector cer tifications, and interviewed two NDE inspectors for their understanding of the erosion/corrosion program, use of instruments, and importance of grid locations for trending of data.
The inspector confirmed that the latest procedures were used to perform the R6 outage inspection, and that the licensee NDE inspectors who performed the inspections were certified at the time of the inspections.
The inspector observed that the NDE inspectors performed proper calibration checks using calibration instrument blocks.
The inspector concluded that the NDE inspection personnel were familiar with the erosion/corrosion program and were qualified to use instruments required to perform the inspections.
The inspector was unable to observe actual in-plant NDE inspections due to plant operating status.
g.
te d
e ceme t The inspector reviewed one weld buildup repair package, BDC-89-0430-OA (NMR AR-4316)
"Meld Buildup for Modification of Orifice" (HV-R0-41B),
one material replacement package, PHR-0433-0 "Heater Drain Tank Drain Piping Replacement at Reactor Feedwater Heat Exchanger 6A & 6B, and one design change package BDC-89-0430-0A, "Hoisture Separator Reheater Vent Line/Orifice Reconfiguration,"
which were performed based on erosion/corrosion program analysis and inspection results.
The inspector concluded that the packages were prepared and documented in accordance with plant procedures.
h.
o ra e
c es The program did not provide guidance for expanding the scope of the inspection sampling when a pipe or component in a system was identified as having excessive wear.
The inspector reviewed expanded inspection selections for two lines, High Pressure Turbine Exhaust to Low Pressure Heater Line COND-HX-5A and 5B, which were identified as having areas of high erosion/corrosion rates in specific components.
The inspection sample expanded from two points to seven points from R2 to R3 to ten sample points in R4.
The inspection points for the lines were reduced to two sample points for R5 and R6 outages based on R3 and R4 inspection results.
Based on the increase in sample inspection points, the inspector concluded that adequate inspection point expansion was being used despite the lack of written guidanc Oata records, calculation records, and data spread sheets were not specified by procedures.
Oata was available in the responsible engineer's files.
However, the documentation was not clearly labeled, or identified in a controlled manner.
The data, calculations, and spreadsheets were not independently verified.
The personnel involved stated that documents were reviewed by the engineer's supervisor.
However, no documented verifications were available.
The inspector concluded that there was a lack of procedures or program guidelines to define documentation methods.
4, e
v
The licensee's Pipe Mall Thinning Program Plan was implemented by procedure
&.3.63, "Surveillance Procedure for Monitoring Pipe Wall."
The inspector reviewed the management of the WNP-2 erosion/corrosion program and noted the following:
a0 S
The inspector reviewed Supply System PPH procedure 8.3.63 and the
"WNP-2 Pipe Mall Thinning Program Plan."
The two documents defined specific responsibilities of the Plant Technical Hanager and the Hanager of Haterials and Inspection, and others, within the program.
However, the inspector noted that neither PPH procedure 8.3.63, or the MNP-2 Pipe Mall Thinning Program Plan established the responsibility or authority for the overall program.
A program implementation procedure did not exist.
The inspector noted the following examples of deficiencies resulting from the lack of an implementing procedure within this area:
~
Lack of documentation requirements for delaying or deleting specific items from the inspection plan,
~
lack of requirements for documenting or verifying calculations, data input, or program results.
The licensee agreed with the inspector's findings, and committed to place the WNP-2 erosion/corrosion program in the WNP-2 Engineering Management Guidelines program.
This item is inspector follow-up item 50-397/92-10-01.
b. ~ii The inspector reviewed two WNP-2 Corporate Licensing 5 Assurance Audits,90-536 and 91-557, and one Technical Assessment,89-011.
The two audits and one technical assessment included assessments of the erosion/corrosion program.
The inspector confirmed that the items noted in the Corporate Licensing and Assurance audits were addressed and resolved.
However, the items noted in the technical assessment had not
t I
been resolved or brought to the attention of the erosion/corrosion group.
The inspector confirmed that the Nuclear Safety Assurance group was aware of this.
"Technical Assessment 92-003 Plan, Erosion/Corrosion Honitoring Program" was scheduled to begin the week of Harch 16, 1992 in response to NRC interest and industry events within this area.
The inspector noted that guality Assurance oversight of the erosion/corrosion program was minimal.
The licensee's plans for increased gA involvement were considered reasonable.
u r
S a
es The inspector identified specific strengths and weaknesses within the implementation of the WNP-21 erosion/corrosion program.
Continuity The personnel developing, performing, and supervising the program have been involved in the program from the inception.
The personnel appear to have a good working knowledge of the program and the cause and effects of erosion/corrosion.
Interfacing The personnel implementing the program have established inter-discipline interfaces (without clear program guidance).
Working level personnel and supervisors within the materials (erosion/corrosion),
piping stress analysis, and thermal analysis interface for concurrence on piping modifications such as snubber reduction or other programs which seek to utilize margins of safety built into the piping design.
Modeling The Supply System erosion/corrosion plan requires that all trains of a system be modeled not just one train of a similar set.
The modeling selection criteria uses a design temperature of 200 degrees F for the selection of a system, which is more conservative than the selection criteria in Generic Letter 89-08 guidelines.
Plant Experience The erosion/corrosion group has made efforts to upgrade the Supply System program based on Supply System problems and other plant operating experiences.
Program The Supply System provided funding for re-entry into the CHECKMATE Users Group (CHUG).
This program will be used to confirm and enhance the present methodology being employed to detepnine erosion/corrosion at WNP-I
Training The Materials erosion/corrosion personnel perform documented training for other technical staff to ensure all disciplines are aware of the importance of the impact of other areas on erosion/corrosion.
g~n~~~ses:
Program Guidance Program guidelines for implementation of the erosion/corrosion program have not been established.
There appears to no individual department or directorate that has the responsibility or authority to coordinate activities.
The program appears to have been operating on the knowledge and skills of the personnel implementing the program.
guality Assurance Lack of a guality Assurance presence in the erosion/corrosion program.
The inspector did not identify any guality Assurance audit that specifically addressed the operation of the WNP-2 erosion/corrosion program.
Within the time period of the erosion/corrosion program two Licensing Assurance Audits and one Technical Assessment were conducted.
Erosion/corrosion was a minor portion of the scope of the Licensing Assurance Audits and the Technical Assessment.
The Technical Assessment, which was completed in January 1990, also identified the lack of program guidance for responsibility and authority for the erosion/corrosion program.
As of the time of this inspection the department responsible for the erosion/corrosion program had not received or been made aware of the Technical Assessments finding nor had any action been taken to resolve the problem.
The inspector's findings were discussed with the Director of Engineering, and members of the licensee's staff at an exit meeting held on March 27, 1992.
During the exit meeting on March 27, 1992, the inspector emphasized that the WNP-2 erosion/corrosion program was being implemented without detailed program requirements.
In response to this finding WNP-2 committed to include the erosion/corrosion program in the Engineering Management Guidelines Progra P i