IR 05000237/1992017
| ML17177A528 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/09/1992 |
| From: | Jeffrey Jacobson, Schapker J, Ward K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17177A527 | List: |
| References | |
| 50-237-92-17, 50-249-92-17, GL-89-08, GL-89-8, IEB-87-001, IEB-87-1, NUDOCS 9207150034 | |
| Download: ML17177A528 (10) | |
Text
U. S. NUCLEAR REGULATORY COMMISSION
REGION III
Reports N ~37/92017(DRS); No~ 50~249/92017(DRS)
Docket Nos.:
50-237; 50-249 *
Licenses No. DPR-19; No. DPR-25 Licensee:
Commonwealth Edison Company Opus West III 1400 Opus Place Downers Grove,. IL 60515 Inspection At:
Dr~sden site, Morris, IL Inspection Conducted:
June_ 22-25, 1992 others in this inspection:
J. Medoff, NRR K. Parczewski, NRR Section Inspection summary 7-~ -~ '-
Date f'q -~1-..
Date Inspection on June 22-25, 1992 (Reports No. 50-237/92017CDRS);
No. '50-249 /92017 (DRS))
Areas Inspected:
Routine, announced safety inspection of the erosion/corrosion (E/C) program (49001).
Results:
No violations or deviations were identifie Based on the results of the inspection, the NRC inspectors noted the following:
0 Licensee activities relative to the long-term E/C monitoring program were being accomplished in accordance with NRC guidance (Generic Letter 89-08) arid licensee commitments and procedure The licensee's E/C program appears to be conser~atively administered and uses state-of-the-art technology to identify and inspect the most susceptible locations of E/ PDR ADOCK 05000237 G
Inspection Summary
0
0 Records were found to be complete and well maintaine Management involvement and commitment to a quality E/C effort was evident. *
A potential weakness was noted (Paragraph 2.e.) in that the procedqre which governed the selection of components to be evaluated for E/C only required a small number of components (potentially as low as 13).
However, actual implementation to date was conservative and far exceeded the required numbe *
.DETAILS Pers6ns Cbntact~d Commonwealth Edison Company CCECo)
- c. Schroeder, Station Manager*
- G. Whitman, ISI/IST Group Leader
.
- B. Viehl, Engineer, Nuclear Engineering Department Site Supervisor
- J.. Foster, Engineer, Nuclear Engineering Department Site
- E:ngineer
- M. Strait, Technical Staff Supervisor
- s. Berg, Assistant to the Production Superintendent
- D. Zoloty, Production Engineer, !SI/Materials
- B. Kanallakan, E/C Coordinator
- E. Carrol, Regulatory Assurance Engineer P. Shafi, Nuclear Quality Programs Engineer ABB Impell Corporation Cimpell)
J. Raumeta, Project Manager
- P. Ksiazek, Supervisor Engineer T. Diamond, *senior Engineer c. Schlatter, Senior Engineer U. s. Nuclear Regulatory Commission. (NRC)
- K. Parczewski, Senior Chemical Engineer, NRR
- J. Medoff, Reactor Engineer, NRR W. Rogers, Senior Resident Inspector M. Peck, Resident Inspector
.
J. Jacobson, Section Chief, Region III The NRC inspectors*a1so contacted and interviewed other licensee and contractor employee *Denotes those present at the exit interview on June 25, 199.
Erosion/Corrosion CE/C) Monitoring Program (49001) Background Commonwealth Edison Company (CECo) implements the Corporate Erosion Corrosion Progr~m for its six nuclear facilities through the Nuclear Engineering Departmen This program is governed by Corporate Directive NOD-.
TS.7, which provides a corporate approach to the predicting, monitoring and evaluating of E/C in single
.or two phase, high energy, carbon steel pipib~
component This includes guidance on the following aspects of the program:
0
-
o*
0 background and nature of E/C; E/C program scope and definitions (covers systein~
selection);
plant operational review and data gathering; inspection point selection; ultrasonic (UT) inspection criteria; repair/replacement criteria; and future inspection plannin Implementatiori of the corporate direction at the individual sites (Braidwood, Byron, Dresden, LaSalle, Quad Cities, and Zion) is accomplished through site specific E/C administrative procedure The Dresden Nuclear Power Station implements the directive through administrative procedure OAP 14-08A which incorporates all the requiremerits stipulated in NOD-T The E/C
. Coordinator is responsible for ensuring that the E/C Program described in OAP 14-08A is properly carried ou Program Scope
- The following systems are included in the CECo E/C Program at Dresden:
- condensate and condensate booster, feedwater, including the safety related portion located inside containment, turbine gland seal, *feedwater heater drains, and moisture separator drains.. These systems have been documented (industry experience) as being susceptible to E/ The NRC inspectors selected the feedwater system inside containment as the safety related system and the extraction steam, moisture separator drain,. and f eedwater heater drain systems as the balance of plant systems for revie _Inspection The E/C program was reviewed using the NRC onsite inspection criteria listed in Generic Letter (GL) 89-08, "E/C Induced Pipe Wall Thinning," NUREG-134 In addition, a review was performed to ensure that any commitments made to NRC Bulletin 87-01 and GL 89-08 have been implemen~ed. Verification was performed by interviewing personnel involved in the E/C program, reviewing inspection reports and related document (1)
Review of Licensee Methodology for Selecting Components £or Inspection The licensee established a systematic erosion/corrosion control program for the Dresden station in 1~88. In this program, the components
(e.g;, elb6ws, tees, and reducers) selected for inspection were from three sources:*
0
A programmatic list of components selected by predictive c_ode The components.on this list w~re tracked within each subsystem according to their susceptibility to erosion/corrosio *
The previously inspected components-which.
were found to reach minimum allowable wall thickness before the next outage and needed reinspectio *
Components which were selected using industry and operating experienc.
.
The programmatic list included approximately 800 components per unit, selected from systems containing components susceptible to erosion/corrosio The components in the programmatic list were selected using three predictive method The components carrying single phase fluid such as feedwater, condensate, and reactor water cleanup systems, were selected using the EPRI's CHEC computer cod The components carrying two phase fluid were s~lected-either by using the EPRI's CHECMATE code (e.g.,
heater drain~) or* the model described iri EPRI's Report NP-3944 (e.g., extraction steam lines).*
Since the CHEC and CHECMATE codes were used only for ranking the susceptibility of components to erosion/corrosion, they were not.validated by
.
inclusion of the inspection data and therefore did not have the capability for predicting wear rate The licensee does not intend to use these codes for quantitative predictions due to the development of their own systematic program for performing this task (reference Paragraph 2.c.(3)
of this report).
-
The components selected for.inspection from industry experience contained 80 components* for Unit 2 and 88 components for Unit Approximately half of these components have been inspected to date~
The licensee's procedure called for starting the
- program by selecting one component from each system and then expanding the sample as components were identified_ as.being affected by
..
erosion/corrosio Also, components from the industry experience list were added as require As a result, the total number of componerits inspected during an outage has varied between 40 and 6 This number did not include inspection of straight runs of piping since this is not included in the programmatic or industry experience lists.*
However, as a rule, each component "inspection.
- included the length of two diameters of piping downstream of the inspected component and, if significant erosion/corrosion damage was found, this inspection was extended to five additional diameter In this way, piping was implicitly included *in the inspection program,eff~ctively doubling the actual number of components selected for inspectio Therefor~, although the initial sample specified by the procedure appeared low, the NRC inspectors found that the actual number of components selected for inspection during an outage was adequat The input to-the codes used to select and rank the components came from the plant's isometric drawings and other sources of information available to the plant personne The input was prepared and the code analysis performed by a
- . contracto The inspectors reviewed the input and output data to the codes and concluded that th selection and ranking procedures were acceptabl Components in the Dresden E/C program included tees, reducers/expanders, exit nozzles, flow orifices, traps, elbows, and control valve The E/C section of the Dresden ISI Department has also included the f eedwater heater shells among the compo~ents for inspection since t~ey consider th~m to be part of the extraction steam syste Components are selected for inspection for the next refueling outage based upon a priority (i.e, ranking)*basi The E/C Coordinator designates components for inspection based on the stated
- criteri (2)
Component Inspection Methodology The licensee contracts the services of a professional nondestructive testing laboratory to perform UT measurement examinations and record the dat The NRC inspectors verified that the UT inspectors were certified to SNT-TC-lA requirement The inspection grid size for nominal pipe size 10 11 and less is 1 11 X 1 11, pipe sizes 10" to 20 11 requires a 2 11 X 2 11 grid and all sizes greater than 20 11 require a 3 11 X 3 11 gri Each grid is *
permanently marked at the reference point with a 1/4" 110 11 stamp with each intersecting grid location permanently stamped with a 1/2" 110 11 *
, stam This method.assures. repeatability for future reexaminations to accurately measure wear rate The grid size required* by the licensee's procedure is conservative and exceeds industry practic The licensee requires the use of UT machines with digital and "A" scan presentation, the use of 110 11 meters is not permitte The data.is recorded by the UT inspectors with an electronic data logger which is downloaded directly-into the computer program~ These inspections are normally scheduled during a refueling outage and are the res~onsibility of the.inservice examination (ISI)
engineering departmen The licensee's procedure for measurement of wall thickness and data logging is state of the art and exceeds industry practice in conservatis.
(3)
UT Data Analyses and Evaluations Commonwealth Edison hired an outside engineering contractor to assist with the evaluations of UT measurement The E/C group performs the evaluations by* means.. of a contractor supplied computer program, CEECCAL CEECCALC is a systematic program which determines whether a component requires immediate replacement/repair,*
reinspection at the next refueling outage, or *
reinspection at some future dat Although CEECCALC has point-to-point capability, it currently bases its evaluations.using the band metho At times, structural evaluations are performed on components to determine the extent of localized thinning and to establish new allowable wall thicknesses.* Components which pass the structural evaluations are inspected at the next outag CEECCALC was implemented after refueling outage 11 in 198 a. Review of Inspection Data Packages for E/C (1)
E/C Inspections The NRC inspectors reviewed the packages in the extraction steam,. feedwater heater drain, and moisture sep~rate drain systems (balanbe of plant systems).
The inspectors noted that in the CEECCALC evaluation of component 3EZ01B (Unit 3 extraction steam system), the wal.l thickness utilized for the calculation (band 33) was not the band exhibiting the maximum wear (band 51).
The inspectors inquired whether use of band 33 for the calculations would yield accurate results in the structural evaluations, since cases could be made where the use of band 51 could yield greater**
values of projected wea Discussions with the licensee revealed that CEECCALC takes this into account since it has the ability to iun evaluations of all bands in the gri Review of the structural evaluations for this component indicated that the structural *
integrity of this component was acceptable until the next refueling outage when the component was scheduled for reinspectio The inspectors had no further* questions with regard to this component*.
The inspectors also reviewe.d the packages of the feedwater tees* inside containment (nonisolable, Class I system components).
All packages reviewed complied with procedure and CEECCALC requirement One reducer adjacent to tee 2FR21A-3, appeared to exhibit some wear (refueling outage 11) in th reducing portion of the component; however, it is difficult to obtain accurate UT measurements in this portion of the reducer since it is in a oblique region of the componen Re-evaluations by the contractor indicated that this component would maintain its integrity until the next refueling outag Re-inspections of 2FR21A-3 during refueling outage 12 yielded UT data which indicated that the component had 33 months of remaining lif The licensee's methodology of evaluating wear rates was found to *be conservativ (2)
Repair and Replacement Program The NRC inspectors reviewed the following work request packages:
0 No. 003846, extraction steam, low pressure heater bay (a patch welded on a thin area).*
No. 003995, 24" L.P. turbine nozzle to C2 heater (clamshell installation).
The NRC inspectors reviewed the following and other related documentation in each package:
0
0
0
work requests; receiving inspection reports; bill of material; training reports; welding reports; drawings; welder qualifications; and QC certification The data reviewed complied with the applicable Code and proced~re requirement (3)
Review of Final Reports for all E/C Inspections*to Date The NRC inspectors reviewed the.E/C final reports for each refueling outage to evaluate the content and action take The.final report contains recommendations for corrective.actions and preventive maintenance such as repair or replacement of piping and c;omponents, re-inspection of piping and components within a specific time schedule, and inclusion of additional piping and componerits o~ similar design and operating characteristics based on industry and inspection experienc The licensee's corrective action in response to these recommendations was found to be conservative and responsive in 'all reports reviewe Conclusion The NRC inspectors concluded that the licensee'~ EC inspection and evaluation program complied with the guidelines stated in GL 89-0 Implementation of the E/C program was. found to be generally conservative; however, the NRC inspectors foun~ a potential programmatic weakness which involved,the selection proces The-E/C Inspection Program procedure, OAP 14-08, Revision 2, Paragraph F.1.b., Programmatic Ranking Selection, only required a selection of the most susceptib)..e component of_ each.subsystem (there are 13
I
.
subsystems).
This programmatic inspection number i considered small and nonconservativ *
- ~
The E/C program was well defined and responsibilities and management support/interest were eviden Overall,
. the program was well developed and should play a major
.role in maintaining plant safety, efficiency, arid reliability in the futur No violations. or deviations were identifie.
Exit Interview The inspectors met with licensee representatives (denoted in
- Paragraph 1) at the conclusion* of the inspectio The inspectors summariz~d the s*cope and findings of the inspection activities~ The licensee acknowledged the
- inspection finding The inspectors also discussed the likely informational content of the inspection report with regard to documents or processes *reviewed by the inspectors during the inspectio The licensee did not identify any such document/processes as proprietar.----* - ------
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