IR 05000304/1992033
| ML20034F246 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 02/23/1993 |
| From: | Jeffrey Jacobson, Schapker J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20034F244 | List: |
| References | |
| 50-304-92-33, NUDOCS 9303020476 | |
| Download: ML20034F246 (9) | |
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U.
S. NUCLEAR REGULATORY COMMISSION
REGION III
Report No. 50-304/92033(DRS)
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Docket No. 50-304'
License No. DPR-48 I
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Licensee:
Commonwealth Edison Company.
Opus West III 1400 Opus Place Downers Grove, IL_ 60515 Facility Name:
Zion Station - Unit 2 Inspection At:
Zion Site Zion, IL r
Inspection Conducted:
December 3, 15-16, 1992,' January 6-7, 28, 1993 2/.23 93 Inspector:
F.
Schapker D,dte /
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f Accompanied'By:
B..Metrow, IDNS
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2/15/93 Approved By:~'
,.2 A
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.'M. Jacobso Chief Date'
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[.aterialsandp,rocessesSection
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Inspection Summary
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Inspection on December 3, 15-16. 1992: January 6-7.
and 28. 1993 (Recort No. 50-304/92033(DRS))
Areas Inspected:
Routine, announced safety inspection of inservice inspection (ISI) activities including review of programs (73051), procedures. (73052), observation of work-
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activities (73753), data review (73755), and Erosion / Corrosion Program (49001).
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Besults:
No violations or deviations were identified.
Based on
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following:
i All ISI activities were controlled by well stated and defined procedures, j
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The ISI contractor personnel were knowledgeable'and utilized
state of the art equipment.
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9303020476 930223
.PDR ADOCK 05000304 G
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Inspection Summary
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Eddy current examination (ET) of. steam generator (SG) tubes
detected continued degradation at the roll transition area within~the tubesheet, no degradation was found in the support plate or free span regions zus found during recent-inspections at other plants with model 51 generators.
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The licensee performed augmented inspections'(100%) of the
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steam. generator tubes.and enhanced procedures as recommended'
by an NRC consultant during a previous inspection (50-295/92008(DRS)).
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DETAILS
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1.
Persons Contacted
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Commonwealth Edison Comoany (CECO)'
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- D.
Wozniak, Technical Staff Superintendent
- D.
Bump, Nuclear Quality Assurance Supervisor
- R.
Chrzanowski, Regulatory Assurance Supervisor
- K.
Dickerson, Regulatory Assurance
- E.
Robey, ISI Group Leader
- R.
Tolentino, ISI Coordinator
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Combustion Enuineerina Corporation (CE)
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Russel, ET Level III H
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Edwards, ET Level III
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Westinahouse Electric Corporation (WE)
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Halen, Site Supervisor i
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Nuclear Reculatory Commission (NRC)
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Smith, Senior Resident Inspector-R.
Leemon, Resident Inspector
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Illinois Department of Nuclear Safety (IDNS)
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B.
Metrow, IDNS Inspector Hartford Steam Boiler Inspection and Insurance Company (HSB)
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Oakley, ANII The NRC inspector also contacted and interviewed other licensee and contractor employees.
- Denotes those present at the exit interview on January 28, 1993.
2.
Inservice Inspection a.
Procram Review (73051)
Personnel from CE, WE and CECO performed the ISI in accordance with ASME Code Section XI, 1980 Edition,
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Winter 1981 Addenda.
Where ASME requirements _.were.
determined.to be impractical, specific relief requests were submitted to thel Office of Nuclear Reactor
' Regulation (NRR) in writing.
The NRC_ inspector reviewed the specific relief requests including the
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related correspondence between the licensee and the NRC.
The NRC inspector reviewed CECO Nuclear Quality Programs-Audits and Technical Staff Surveillances of ISI activities.
The audit and surveillance activities
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were well planned and implemented in accordance with'
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the. licensee's procedural requirements.
Overall organizational staffing.for the ISI program was found
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to be acceptable.
b.
Procedure Review (73052)
All applicable ISI procedures were approved.by the
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Authorized Nuclear Inservice Inspector (ANII) and were-
found to be acceptable and in accordance with ASME Sections XI and V, 1980 Edition, Winter 1981 Addenda.
c.
Observation of ISI Work Activities (73753)
The NRC inspector observed work activities and had discussions with personnel during the ISI activities.
These observations included the following:
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Eddy current examination (ET) of the steam
generator tubes.
r Ultrasonic examination-(UT) of Reactor Coolant-
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System (RCS) Loop piping, safety injection piping,
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and residual heat removal (RHR) piping welds.
Magnetic particle examination' (MT) of Reactor
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Vessel Closure Head (RPV)' Studs.
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Liquid penetrant examination (PT) of RCS piping,
Safety Injection system (SI), RHR pipe welds.
Visual examination (VT) of reactor vessel interior
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surfaces, RHR flange and check valve bolting, and RPV studs.
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The NRC inspector reviewed the qualifications and l
certifications of all inspection personnel onsite performing ISI to ensure compliance with SNT-TC-1A requirements.
d.
ISI Data Review (73755)
The inspectors reviewed ISI documents relating to the following:
NDE data sheets for UT, MT, PT, ET, VT
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NDE equipment certifications and calibration
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l Certification of NDE inspectors.
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The examination. data complied with the requirements of
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the ASME code and applicable procedures.
The NRC l
inspector noted that the licensee did not identify SG tube anomalies (Distorted roll transition' indications o
(DRI)), as being defective as described in the Zion Technical Specifications (TS) (see paragraph 3'of this-report).
No violations or deviations were identified.
3.
Eddy Current Examination and Repair of the SG Tubes The licensee employed the services of Combustion Engineering'
Corporation to perform the ET of the Unit 2 SGs.
A multifrequency ET was performed using-four data stations in parallel, probing from the hot and cold legs of the SGs.
One hundred percent of the tubes in all four SGs were inspected full length for those tubes accessible.- The bobbin probe ET was used for the full length examination.
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Distorted indications (DI) found during the bobbin coil'
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examination were reinspected with the motorized rotating pancake coil-(MRPC).
All sleeves were inspected with the:
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sleeve crosswound coil probe.
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MRPC inspections of 115. tube support plate-intersections, 100% of the row one and two U-bend areas, and 556 roll
transition and crevice regions were performed.
The NRC inspector observed the ET in progress and reviewed j
the following documents:
CECO Zion Station Eddy Current' Data Guidelines.
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Steam Generator ET report.
- Zion Technical Specifications.
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ET Graphics and Data reports.
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ET of the Unit 1 steam generator tubes identified the following:
"A" SG
"B" SG
"C" SG
"D" DRI 176
30
DRT 160
65 l 51 -
DNT
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NQI
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0-19%
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31 20-39%
117
32
40%>
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3 DRI= Distorted roll indication DRT= Distorted roll transition DSS = Distorted support plate signal NQI= Non-quantifiable indication
%= thru-wall measurement of indication The following SG tube repairs were performed:
S_GG Pluu Sleeve
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A
145 B
0 C
25
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D
0 E
All of the above tubes were plugged with Inconel 690 welded plugs or welded sleeves.
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The licensee also replaced Inconel 600 plugs with Inconel 690 welded tube plugs in accordance with NRC Bulletin 89-01.
Although the licensee plugged or sleeved all the tubes with confirmed DRI's, the tubes with these defects were not classified as defective as described in the. Zion TS Section-
4.3.1.B, Steam Generators.
TS paragraph 4.3.1.B.4, Acceptance Criteria, subparagraph A.5, defines Defect as an imperfection of such severity that it exceeds the plugging limit.
A tube containing a defect is defective.
Paragraph A.6, defines the Pluccina Limit as an imperfection depth at or beyond which the tube shall be
removed from service and is equal to 40% of the nominal wall thickness.
It is often impossible to measure depth of penetration of.
crack-like DRI's into the tube wall.
Therefore, it-is
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uncertain whether the indication exceeds or is less than the l
40% of the tubes nominal wall.
Although the-licensee did not classify'the DRI's as defective, corrective action to
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repair the defects (plugging or. sleeving the tubes) was adequate.
The licensee classified the tubes as being degraded and they were conservatively plugged or sleeved.
The NRC inspector informed the licensee that this classification may not meet the NRC regulatory requirements as described in the TS referenced above and is an unresolved item pending the.results of NRC review (50-304/93022-01(DRS)) (reference NRC inspection report 50-456/92021(DRS).
The licensee's SG inspection program is conservative and corrective actions were implemented as required.
No violations or deviations were identified.
4.
Erosion / Corrosion Procram (49001)
The inspectors reviewed the Zion Stat' 1 Erosion / Corrosion Program, TSGP-138, Revision 0.
The program provides for the conservative calculation of estimated wear rates based on measured thickness and comparison of this value with previous measured thickness and calculated wear based on material, chemical, temperature, flow phase / rate, pressure, and pH.
The program includes the use of EPRI CHECMATE and the CECO, CEECALC programs and provides for the selection of additional components based on industry experience, NRC Information Notices, IMPELL recommendations, plant modifications, replacement of failed' components, and CECO corporate engineering recommendations.
The inspectors interviewed the Zion Station coordinator regarding implementation of the program, and observed the
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ultrasonic examination data gathering and processing.
The licensee and contractor employees complied with the referenced procedure requirements.
During this' outage, 42 components were inspected, with 126 examinations performed.
The licensee's erosion / corrosion program appears to be conservative and adequate to prevent catastrophic failure of piping components susceptible to this type of degradation.
No violations or deviations were identified.
5.
Modifications (37701)
a.
Auxiliary Feedwater (AFW) Pump Discharce Check Valve Replacement ModificatioD This modification consisted of replacement of existing swing-type check valves at the discharge of the three AFW pumps with new lift-type check valves.
The licensee replaced similar valves in the Unit 1 AFW system during the Spring 1992 outage-(reference NRC-
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inspection report 50-295/92008(DRS)).
The piping system and the valve replacement modification were designed in'accordance with the ANSI B31.1 Code.
- The preservice and inservice inspections were'in accordance with ASME'Section XI requirements.
The inspector reviewed the safety evaluation, design specification, work traveller, welding materials, NDE
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records and related documentation.
b.
Service Water System (SW) Isolation Valve Installation Modification This modification consisted of installing or replacing
numerous valves in the service water system.
A portion j
of this modification was reviewed by the inspector.
This portion specified installing additional valves on supply and return lines for the 2A and 2B emergency diesel generator SW coolers.
Three safety-related and
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four nonsafety-related valves were installed as part of the modification.
The new valves provide additional'
isolation capabilities to allow periodic maintenance on existing isolation valves. The work, materials and equipmen conformed to the ANSI B31-1-1967 Code and the ASME Code Section XI ?980 edition.through'1981 addenda.
The inspector observed fit-up of valve 2SW1755, including dimensional tolerances, tack welds, and cleanliness.
Review of the modification package, work request, maintenance / modification procedures,Section XI repair / replacement program, QC field monitoring reports, NDE data reports, and test equipment I
calibration records.
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i The inspector reviewed the hydrostatic test procedure and test results.
The procedure defined acceptance criteria which complied with the ASME Code Section XI requirements.
The completed procedure included'the licensee's review and evaluation of test results.
No violations or deviations were identified.
6.
Unresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, violations or deviations.
An unresolved item disclosed during this inspection is discussed in Paragraph
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3.
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Exit-Interview (30703)
The NRC inspector met with licensee representatives (denoted in Paragraph 1) at the conclusion of the inspection on January 28, 1993, and summarized the scope and findings of the inspection noted in this report.
The NRC inspector also discussed the likely informational' content of the inspection report with regard to documents or processes reviewed by the inspector during the inspection.
The licensee did not-identify any such documents / processes as proprietary.
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