IR 05000413/1993004
| ML20034E930 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 02/19/1993 |
| From: | Blake J, Kleinsorge W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20034E920 | List: |
| References | |
| 50-413-93-04, 50-413-93-4, 50-414-93-04, 50-414-93-4, GL-89-08, GL-89-8, NUDOCS 9303020094 | |
| Download: ML20034E930 (10) | |
Text
{{#Wiki_filter:[/* %Q[0,, UfdlTED STATES
NUCLEAR REGULAVORY COMMISslOh! ' o REGION 11
g $ 101 MARIETTA STREET.N.W.
$' M ~*
ATLANTA, GEORGI A 30323 o,.
- %... o #,a FEB 2 21993
, Report Nos.: 50-413/93-04 and 50-414/93-04
Licensee: Duke Power Company r P.O. Box 1007 < Charlotte, N.C.
28201-1007 Docket Nos.: 50-413 and 50-414 License Nos.: NPF-35 and NPF-52 Facility Name: Catawba Nuclear Station Units 1 and 2
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Inspection Conducted: February 8-12, 1993 Inspector: // hfd3 X.
. Kleinsorge P.E.
Date Signed R ctor Inspector
Approved by: f
J.
.~Blake, Chief Date Signed . erials and Processes Section E gineering Branch Division of Reactor Safety-SUMMARY ! Scope: This routine, announced inspection was conducted onsite in the following areas: Inservice Inspection (ISI); Residual Heat Removal (RHR) system line break; Diesel Generator Cooling Water Heat Exchaager (DGCWHX) failures; ' followup on NRC Generic Letter (GL) 89-08 " Erosion / Corrosion-Induced Pipe Wall Thinning"; and Unresolved Item: 50-413,414/92/30-03: " Priority 2 PD Procedures Due Complete December 31, 1992".
' Results: The Review of the licensee's Inservice Inspection (ISI) program indicates ! adequate management and control of the program currently in place. NDE ' procedures were noted to be very detailed, well organized and technically , ' effective in implementing the applicable code requirements. The licensee's
ISI Coordinator, level III examiner, and NDE supervisors were actively i involved in the resolution of technical issues and en;uring that all quality
objectives were properly addressed by examiners.
, To date, the licensee has taken appropriate actions in response to the RHR line break, and the DGCWHX failures.
9303020094 930222 PDR ADOCK 05000413 , G PDR , .-.
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g .. It appears that the licensee has established an effective program to maintain ! high energy carbon steel piping systems within acceptable wall thickness
limits.
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--- , ? . . REPORT DETAILS l +
1.
Persons Contacted l Licensee Employees
J. Cherry, Quality Assurance (QA) Specialist-QATS -
- R. Giles, Inservice Inspection (ISI) Coordinator
- T. Harrall, Safety Assurance Manager
- J. Lowery, Compliance
~; W. McCollum, Station Manager
- R. Propst, Manager Chemistry t
- D. Smith, Nuclear Generation Engineer r
Other licensee employees contacted included, engineers, technicians, , security force members, and office personnel.
NRC Resident Inspectors.
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- W. Orders
' P. Hopkins J. Zeiler
- Attended exit interview.
I ' Acronyms and initialisms used throughout this report are listed in the-1ast paragraph.
.j 2.
Inservice Inspection (ISI) , The inspector reviewed documents and records, and observed activities, as i indicated below, to determine whether ISI was being conducted-in accordance with applicable procedures, regulatory requirements,.and licensee commitments. The applicable code for ISI, for both Unit 1 and ! Unit 2, is the ASME B&PV Code, Section XI, 1980 edition with addenda- ' through winter 1981 (80W81). Unit 1,.in their seventh fuel cycle, is
operating in the third 40 month period, of the first ten year ISI.
interval (P3,II). Unit 1 received their. operating license on January 17, 1985 and commenced commercial operations on June 29, 1985.
' Unit 2 received their operating license May 15, 1986 and commenced .; commercial operations on August 19, 1986. Unit 2 is in their.fifth refueling outage, the third outage of the second 40 month period, of the ' first ten year ISI interval (03,P2,II). The~ licensee's nondestructive , examination personnel are performing the liquid penetrant (PT), magnetic ! particle (MT), ultrasonic (UT), and eddy current.(EC) examinations.- !
a.
ISI Program Review, Units 1 and 2'(73051) I The inspector reviewed the following documents relating to the ISI program to determine whether the plan had been approved by the
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- licensee and to assure that procedures and plans had been ' established for the applicable activities.
Unit 2 ISI Plan for Outage 3 Period 2, Interval 1
Unit 2 Ten Year ISI Plan b.
Review of NDE Procedures, Units 1 and 2 (73052) > The inspector reviewed the procedures listed below to determine whether these procedures were consistent with regulatory require-
' ments and licensee commitments. The procedures were also reviewed for technical content.
Procedures Reviewed ID Revision FCR . Title NDE-C (R4) 92-13 Control of Nondestructive Equipment NDE-25 (R14) 92-2 Magnetic Particle Examination Proce-dure and Techniques NDE-35 (R13) 92-16 Liquid Penetrant Examination NDE-44 (R9) 92-12 Ultrasoi.ic Examination of Bolts and Studs l ' NDE-600 (R2) Ultrasonic Examination of Similar Metal Piping Welds in Wrought Ferritic and Austenitic Material ' NDE-620 (RI) 92-18 Ultrasonic Examination of Welds in Wrought Ferritic and Austenitic i Pressure Vessels 2 Inches in Thickness and Under NDE-680 (RO) 92-19 Ultrasonic Examination of Nozzle Inner - Radius In Ferritic Pressure Vessels-l The inspector noted that all procedures reviewed appeared to contain the necessary elements for conducting the specific examination.
c.
Observation of Work and Work Activities, Unit 2 (73753) ' The inspector observed work activities, reviewed certification records of NDE equipment and materials, and reviewed NDE personnel ,' qualifications for personnel who had been utilized in the ISI-examinations during this outage. The observations and reviews ! conducted by.the inspector are documented below.
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Magnetic Particle (MT) Examination
The inspector observed the MT examination of weld 2CF37-59, a 18-inch x 0.938-inch butt weld in the Auxiliary Fee h ter (AF) system.
I;ie inspector performed an independent evalm ion of the indications obtained to confirm the NDE examiner's evaluation.
The inspector reviewed the certification documentation for gray MT powder Batch No. 87F008, yoke CNO-36, and test weight No. MTC-1.
! The inspector reviewed the certification, qualification, and visual acuity documentation for MT-II examiner BC.
The inspectors noted the following relative to the MT examination observed: o Although marginally acceptable contrast was obtained between the gray MT powder and the bright metal finish of the weld indicated above, significantly better contrast would have been obtained had red or black powder been used.
The examination was performed satisfactorily.
d.
ISI Records Review, (73755) The licensee has replaced pipe and fittings in the AF system in, accordance with their repair and replacement program, and ASME B&PV Code Subsection IWA 7000.
The inspector reviewed records associated with this replacement to ascertain whether the activities were accomplished in accordance with procedural and regulatory i
requirements, as indicated below.
, The inspector examined Corrective Action Work Order Package
92055230-01 with the associated welder qualification and welder ' qualification maintenance records; NDE personnel qualification certification and visual acuity records; welding filler material
certification and receiving inspection documentation; Welding , Procedure Specifications (WPSs) and their supporting Procedure , Qualification Records (PQRs); for the personnel, welding materials
and welding procedures involved in the replacement as indicated l below.
l i Welders H-2986 R-6828 F-9247 , Welding Filler Material i E-7018 3/32" 2026AJ01 ! ER-705-2 1/8" L22289 ER-705-2 3/32" 97404
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NDE Examiners JEH W CEF W HEE W, PT-Il ' RDB W, PT-Il LHH W,PT-II KWL RT-II DAT RT-II WPS Examined WPS PQR L-250 L-102 L-350 L-103 , The inspector determined that the AF system pipe and fitting re-placements were made oy properly qualified welders using certified welding filler material in accordance with a qualified welaing procedure specifications, and examined and tested in accordance with appropriate procedures by qualified personnel.
Within the areas examined, no violations or deviations were identified.
! 3.
Residual Heat Removal (RHR) System Line Break
On January 31, 1993, with Unit 2 in mode four, Reactor Coolant (RC) l ' system at 340* F and 375 psig, and preparations in progrc s to establish ! RHR cooling using the 24 RHR train, the RHR system sustained a water
hammer severing RHR system vent valve ND-5 from the system. According to ! the licensee, the break occurred at the toe of socket weld 2ND-32-14 in
the pipe down stream of elbow H as depicted on DPC drawing CN-2ND-32 Revision 8.
The elbow and the up stream fracture surface as well as the
down stream fracture surface and pipe segment have been sent to Babcock
and Wilcox (B&W) for metallurgical evaluation.
Prior to submitting the i specimens to B&W for evaluation, the licensee with B&W personnel per-L formed a field visual examination of the fracture surfaces at 40X magnification.
The licensee indicated that the fracture followed the -[ fusion line at the OD surface and propagated through the base material to
the I.D. surface.
Beach marks indicative of high cycle fatigue were noted in the areas from the 4:00 to 8:00 and 11:00 to 1:00 positions, on i the fracture faces. The pipe did not appear to be bottomed in the socket. 19 weld defects were noted on the fracture surfaces. The licensee expects the report of.the metallurgical evaluation the week of ! March 1, 1993.
j To determine whether there were cracks in other similarly configured vent -
lines on the RHR system, the licensee PT examined 24 welds in the Unit 2 RHR system and six welds in the Unit 1 RHR system.
The inspector conducted interviews with licensee personnel and examined
pertinent quality records to evaluate the licensees actions in response ! to the failure. The records examined included: construction and post failure PT examination reports; PT examiner certification and visual . acuity records; penetrant material certification and receiving inspection f
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5 . , . records; base material and welding filler material certified material test reports, weld travelers and welder qualification records for Weld
Nos 2ND-32-12, -13, -14, and -15.
, ' To this writing, within the areas examined, the licensee has taken appropriate actions.
Within the areas examined, no violations or deviations were identified.
. 4.
diesel Generator Cooling Water Heat Exchanger (DGCWHX) Failures As reported in NRC Inspection Raport 50-413,414/92-29 the site had two tube failures in the Unit 2 DGCWHXs.
On October 22, 1992 the 2A D;CWHX experienced a complete circumferential , tube break in a periphery inlet tube at approximately the 10:00 position i (R 08 C 1). On November 17, 1992 a leak was identified in 2B DGCWHX.
, T;,'s leak emanated from a circumferential-opening extending approximately ' 270" around the circumference of a periphery outlet tube at approximately the 5:00 position (3 04 C 16).
Both failures were located midway between the return end floating tube sheet and the first baffle plate. - The first . failure (2A DGCWHX) was in situ visually examined, plugged and returned I to service, in the second failure, the failed tube section was removed l from the 2B DGCWHX, and subjected to metallurgical examination. This , examination included macro-examination, fractography, metallography, ' chemical analysis and physical testing. In addition to the 270" circumferential through wall opening, numerous parallel circumferential cracks, were noted,15-25% through the 0.057" wall 18 BWG Admiralty Brass
tubing. The opening was characterized as irregular, resembling pits - connected by ligaments. The ligaments contained fine cracks. The cracks
all extended from the bottom of shallow pits. The cracks were j non-branching, transgranular, oxide filled and originated from the I.D..
l The tube side environment is raw cooling water with seasonal temperature , variations of 40-90" F.
The shell side environment is a ' ' nitrite / borax / copper inhibitor treated water at approximately 150* F.
. The licensee has employed this chemistry since winter of 1984.
This chemistry was approved as an acceptable chemical inhibitor in diesel l jacket water systems by Transamerica Delaval the diesel supplier.
.; Transamerica Delaval supplied the DGCWHXs with the diesels. In addition the licensee has conducted qualification testing for this chemistry.
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The eddy current (EC) examinations conducted during the'last refueling , ' outage on the DGCWHXs, did not indicate any circumferential indications.
However the licensee indicated that the technique used during the last .' outage was not sensitive to circumferentially oriented indications. The licensee further indicated that the EC examinations planned for this
outage will include a technique specifically intended to identify
circumferentially oriented defects.
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j - l To this writing, within the areas examined, the licensee has taken j appropriate actions.
i Within the areas examined, no violations or deviations were identified.
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Followup (92701)
a.
NRC Generic Letter (GL) 89-08: " Erosion / Corrosion-Induced Pipe Wall Thinning" The licensee has established a has established a Flow Accelerated Corrosion (FAC) inspection program which uses the CHECMATE* EPRI
(Electric Power Research Institute) computer code, the Keller " Equation, industry experience, and previous inspection data as - predictive tools for the determining and prioritizing inspection ' locations.
- ! The licensee's CHECMATES electronic model includes the systems that have been predicted to be susceptible to FAC, which ranks the i systems components according to their FAC susceptibility.
The licensee's primary basis for the selection of components for ultrasonic (UT) examination during the next refueling outage is the ' results of previous ultrasonic examinations.
In addition.to the results of previous ultrasonic examinations the licensee uses: s engineering judgement, including plant specific design r characteristics; predictive analyses; and industry and operating experience. The licensee has criteria for excluding a system from-the FAC program.
The licensee's FAC program includes the following i systems: Feedwater; Condensate; Feedwater Heater Drains; Moisture , Separator Drains; Moisture Separator Reheater Drains; Extraction ! Steam; Steam Generator Blowdown; Main Steam; Main Steam Drains;
Auxiliary Steam; Auxiliary Feedwater Pump Supply; Crossover and Crossunder piping; and Steam Seal Supply. Components in the licensee's program include: control / check valves; tees and brar.ches; ! expanders and reducers; flow nozzles and orifices; exit nozzles; and i elbows and reducing elbows.
The licensee's procedure for performing UT thickness examinations
of carbon steel piping is approved by the management review I committee defined-in Section 6.0 of the licensee's Technical , Specifications.
The licensee's procedures define the method for the following: performing U1 meanar~aer.t;; grid marking the inspection zone; ensuring locatior. repeatability on followup UT examinations;- j ensuring certified UT examiners perform the examinations; and establishing acceptance criteria for evaluating UT data. The- , licensee program provides guidance only for analyzing results of UT ' measurements (there are no firm requirements in this area).
The criteria for establishing minimum wall thickness (tsn) requirements , for safety-related (SR) piping is to set t, to.875 of nominal l m wall thickness or is determined from the stress analysis. The , t ! .
- criteria for establishing t,, requirements for Balance of Plant m (BOP) piping is to set t, to code allowable thickness only.
o The wear rate (wr) calculation method is determined on a case by case basis. The predicted thickness (t a)-[t .u-(wr x current y m operating cycle time)) for previously measured components and t y [toso,,-(wr x total operating time to date)] for first time y exauined components. Component acceptability at the next outage is determined by the following method: t ,,,,a > t,, and t a > t m m y wo.
The licensee's method for calculating remaining life (rl) = ( t,,,,a-t,)/w r. m m To date no repairs have been made to ASME Code class 1, 2, or 3 components identified by the FAC program.
Replacement of ASME Code.
cla n 1, 2, or 3 components identified by the FAC program are being accomplished in accordance with ASME B&PV Code Section XI Subsection IWA 7000. The licensee has a repair and replacement program for BOP components which fail to meet the licensee's FAC acceptance criteria.
It should be noted that the program is not contained in a - single document. Welding and nondestructive examination (NDE) of SR and B0P piping replacements are being accomplished by qualified , personnel and suitable procedures.
Both the Corporate Nuclear Engineering Department and the Site Engineering Department are responsible for the implementation of the FAC program. The licensee , does not have formal programmatic requirements assigning the - responsibility for oversight of the FAC program.
The licensee's FAC- , program is not covered by their Quality Assurance (QA) program.
To evaluate the licensee's performance in this area the insoector conducted interviews and reviewed Corrective Work Order package 92055230-01 and Modification Work Order package 9219786-01.
] The licensee does not currently use the T-Dat portion of the CHECMATE program and therefore has missed out on the iterative ' benefits built into the program.
The licensee indicted that they
intend to implement T-Dat for the Unit 1 RF06 data, and for the Unit-j 2 RF05 data.
The calculations used in the program are not proceduralized.
, Notwithstanding the above the licensee has established an apparently effective program to maintain high energy carbon steel piping i systems within acceptable wall thickness limits.
b.
(Closed) Inspector followup Item: 50-413,414/92-30-03: " Priority 2 PD Procedures Due Complete December 31,1992" , The licensee committed to upgrade the remaining Priority 2 Power j Delivery (PD) procedures by December 31, 1992. The inspector i verified that the licensee has completed the task. The licensee
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! - upgraded a total of 35 PD procedures and added a total of nine new.
i PD procedures.
This matter is considered closed.
In the areas inspected, no violations or deviations were identified.
E.
Exit Interview
t I The inspection scope and results were summarized on-February 12, 1993, with those persons indicated in paragraph 1.
The inspector described.the areas inspected. Although reviewed during this inspection, proprietary.
' information is not contained in this report. No dissenting comments were-received from the licensee.
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Acronyms and Initialisms l i ASME - American Society of Mechanical Engineers ! B&PV - Boiler and Pressure-Vessel
B&W - Babcock and Wilcox > ' B0P - Balance of Plant DGCWHX - Diesel Generator Cooling Water Heat Exchanger .j DPC - Duke Power Company , EC - Eddy Current
EPRI - Electric Power Research Institute FAC - Flow Accelerated Corrosion FCR - Field Change Request GL - NRC Generic Letter j ID - Identification ! , I.D.
- Inside Diameter ' ISI - Inservice Inspection - PT - Magnetic Particle - NDE - Nondestructive Examination
' No.
- Number NPF - Nuclear Power Facility
NRC - Nuclear Regulatory Commission
0.0 - Outside Diameter PD - Power Distribution P.E.
- Professional Engineer { PQR - Procedure Qualification Record ! PT - Liquid Penetrant l QA - Quality Assurance ! R - Revision ! Reactor Coolant RC - RF0 - Refueling Outage l RHR - Rarirlual Heat Removal - rl - Reman.ing life
UT - Ultrasonic
SR - Safety Related f ts.
- Minimum Thickness
t,a - Predicted Thickness l WPS - Welding Procedure Specification -{ wr - Wear Rate i I !
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