IR 05000456/1986034
| ML20207G495 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 07/18/1986 |
| From: | Danielson D, Ward K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20207G468 | List: |
| References | |
| 50-456-86-34, 50-457-86-26, NUDOCS 8607230084 | |
| Download: ML20207G495 (6) | |
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l U. S. NUCLEAR REGULATORY COMMISSION i
REGION III
Reports No. 50-456/86034(DRS); 50-457/86026(DRS)
Docket Nos. 50-456; 50-457 License Nos. CPPR-132; CPPR-133 Licensee: Comonwealth Edison Company Post Office Box 767
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Chicago, IL 60690 Facility Name: Braidwood Station, Units 1 and 2 Inspection At: Braidwood Site, Braidwood, Illinois
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Inspection Conducted: June 26 and July 7-9, 1986 b
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Inspector:
K. D. Ward a re 7//f//4 Approved By:
D. H. Danielson, Chief
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Materials and Processes Section Date
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Insp_ection Sumary
n Inspection on June 26 and July 7-9, 1986 (_ Report _s No. 50-_4_56/~86034 JDRS)J~
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Np.50,4578{0[2BD'RlS)}
Areas Inspected: Unannounced routine safety inspection of the resolution of previous inspection findings, of NDE activities and to participate in a meeting relating to UT of cast stainless steel component welds.
Results: No violations or deviations were identified,
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t 8607230084 860718 PDR ADOCK 05000456 G
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i DETAILS
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Persons Contacted Conmonwealth Edison Company _{CECol
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- G. Groth, Assistant Construction Superintendent
- P. Barnes, Regulatory Assurance Supervisor
- E. Netzel, QA Supervisor
- D. Cecchett, Regulatory Assurance
- K. Miller, Senior Quality Assurance Inspector T. Haaker, NDE Level III U. S. Nuclear Regulato_ry Conmis_sion (NRC)
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T. Tongue, Senior Reactor Inspector W. Kropp, Senior Reactor Inspector
T. Taylor, Reactor Inspector
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The inspector also contacted and interviewed other licensee and contractor personnel.
- Denotes those present at the final exit interview on July 9,1986.
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_P_ersonnel Attending the June 267_1986 Meeting
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C. Polito, System Materials Analysis Manager, CECO R. Gaitonde, Supervisory Staff Engineer, CECO W. Witt, NDE Supervisor, CECO D. Christiana, Mechanical Engineer, CECO
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R. Schofield, Project Construction Engineer, CECO D. Zebrauskas, ISI Engineer, CECO
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B. Wilson, NDE Level III, CECO i
T. Haaker, NDE Level III, CECO T. Green, NDE Level III, CECO A. Adamiec, NDE Level III, CECO D. Chrzanowski, PSI /ISI Coordinator, CECO /Braidwood
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M. Sears, PSI /ISI Technical Staff, CECO /Braidwood K. Franczak, NDE Level II, PTL/ CECO W. Caldwell, ANI I, Hartford Steam Boiler Insp. and Ins. Company
E. Sullivan, Materials Engineer, NRC/NRR
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G. Johnson, Materials Engr, NRC/NRR S. Lee, Materials, NRC/NRR
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B. Brown, Senior Engineer, NDE, EG8G/INEL (NRC Consultant)
K. Ward, Reactor Inspector, NRC/RIII
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2.
Licensee Action on Previous __Inspecti_on_ Finding _s n
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(Closed) Violation (4E6/84-05-06; 457/84-05-06): Weld WO-44-FW11 R5 i
was rejected on Pittsburgh Testing Laboratory (PTL) Report No.1460RTRS for incomplete fusion, film station number 3 to 0.
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Weld SI-14-FW9 was also rejected on Pittsburgh Testing Laboratory (PTL) Report No.1537R1 for incomplete fusion, a crack, and root
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shrinkage. Both of the above welds were reinterpreted by the licensee and were fcund acceptable. During the course of the NRC NDE van inspection, the NRC re-radiographed weld WO-44-FW11 R5 and found this weld to be unacceptable as originally reported by PTL.
Weld SI-14-FW9 radiographs were reinterpreted by the NRC and were found to also be unacceptable as reported originally by PTL. Weld CV-17-FW2C R5 at film station No. 22-25 contained incoroplete fusion
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and weld SI-13-FW15 R1, film station No.14 contained drop through which did not c'eet ASME Code density requirements in the area of the drop through. These welds were also accepted by the licensee. During the course of the NRC NDE van inspection, the NRC reinterpreted these
radiographs and found them to be unacceptable.
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In regard.to Weld No. WO-44-FW11 R5, a subsequent review of the radiograph in question prompted CECO to perform a visual examination
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(VT) of the weld 0.D. surface. A VT revealed a surface indication in
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the same area that the NRC had identified incomplete fusion. As a I
result, prior to performing the repair that was connitted to by CECO in the initial response, the weld was re-radiographed to determine if the image of the surface indication corresponded to the same image identified as incomplete fusion on the NRC film. Due to the similarity, the surface indication was mechanically removed and the subject weld was subsequently re-radiographed. The results of the radiographic
examinetien utilizing Kodak "R" film clearly indicated that the indication 1dentified on the initial film, (which corresponded to the
image produced by the NRC) was no lenger present. An explanation as
to why this indication did not appear on the Independent Testing Laboratory's film on file with CECO is that the surface indication
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was not present when initial radiography was performed. The NRC inspector reviewed the final radiographs and reports of the weld and l
j found them to be acceptable.
Due to the questionable indications contained in Weld No. SI 14-FW9, CECO determined that additional examination utilizing greater sensitivity would be perforred prior to making a final preparation. As a result, the weld in question was prepared and ultrasonically examined. This
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was followed by additional radiography of the weld and the results of
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both examinations were corpared and found to be acceptable by PTL, CECc, and the NRC inspector.
A Upon investigation of Weld No. CV-17-FW2C R5 by CECO, it was determined that the site Mechanical Contractor had removed the subject weld per Field Change Order (FCO) No. 7581, dated August 15, 1984. The NRC inspector reviewed the current radiographs for the replacement weld and found them to be acceptable.
The formal instruction coninitted
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in the Corrective Action section of the initial response to the NRC i
was administered to both the Mechanical Contractor and Independent
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Testing Laboratory radiographic interpreters.
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Upon re-review of the radiographs for Weld No. SI-13-FW15 R1, CECO agreed that the isolated area of the drop through did not meet the minimum density requirement as dictated by the density of the properly located penetrameter. As a result, CECO performed subsequent radio-graphy of the affected area and achieved densities that comply with ASME Section V, paragraph T-263.2. Ultrasonic examinations (UT) were also performed and it was found that the internal reinforcement was within ASME Code limitations and was acceptable. The NRC inspector reviewed the radiographs and reports and also found them to be acceptable, b.
(Closed) Unresolved Item (457/84005-07): The review of Southwest Fabrication radiographs by the NRC NDE van personnel for Weld CV-32-10W3 identified a weld indication 1" from film station marker Nc. 1.
This indication was not reported or dispositioned on the radiographic reader sheets and only one film was available for review.
A review by Ceco QA showed that both films were available for review at the time of the inspection.
The inability to locate the second film was not brought to CECO's attention at the time of the inspection.
The film was reviewed and the " indications" appear only on one film and it is an artifact.
The NRC inspector reviewed radiographs, reports, and other related documentation. The actions taken by the licensee were acceptable.
3.
CECO and NRC Meeting to Discuss Ultrasonic Examination of Cast Stainless ~
Steel __ComponentTeld_s
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A meeting was held onsite on June 26, 1986, between CECO and the NRC (See Paragraph I for attendees) to discuss the ultrasonic examination of cast stainless steel component welds. There was a brief description of the procedure qualification program for the following items:
Calibration Blocks
Mock Up Transducers Equipment Owner's Group Samples Personnel Training l
Status of Inspection at Byron 2 and Braidwood 1 Schedule for Remaining PSI
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Cast stainless steel elbows were available at the cancelled Marble Hill plant. CECO personnel visited Marble Hill on January 7,1986, and examined nine statically cast elbows. One 31-inch to 29-inch reducing elbow was selected as having comparable attenuation to that of the Byron /Braidwood castings. This elbow had the greatest variation of attenuation and had an area that had the highest attenuation of all the elbows examined. This elbow was purchased from Marble Hill for processing into calibration standards. Four calibration standard blocks were machined from this elbow; two from the 29-inch diameter end (2.34 inch thickness) which had lower overall attenuation and two from the 31-inch diameter end (2.83 inch thickness) which had higher attenuation. Both axial and circumferential
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side drilled holes (S.D.H.) and inner diameter notches were machined into each block. The S.D.H.'s were 3/16 inch diameter and were located at 1/4, 1/2, and 3/4T locations. The inner diameter notches were machined to 10%,
25%, and 50% through wall depths. The first set of calibration standards (one from the 29 inch end and the other from the 31 inch end) were sent to Krautkramer Branson (KBA) and the second set was shipped to Harrisonics i
Labs approximately 3 weeks later.
KBA and Harrisonics Labs were requested to build search units producing optimum results on the 10% and 25% deep inner diameter notches. Available EPRI recomendations on the design of the search units were also supplied to the manufacturers.
KBA made a set (consisting of one unit for the
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axial scan and one for the circumferential scan) of search units for each block. Each search unit consisted of two 1.0" diameter x 1.0 MHZ, Alpha series flat-faced transducers mounted on contoured, removable wedges that
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produce an approximate 40 to 45, dual, refracted longitudinal wave focused near the block I.D. surface. Harrisonics Labs optimum search unit design was very similar to KBA's, but had cylindrically focused transducers mounted on wedges that produce an approximate 40 refracted L-wave.
Using KBA supplied search units, examinations were conducted by CECO on both calibration blocks using several different UT instruments. The UT instruments available were: Nortec 131, Sonic Mark 1, Krautkramer USIP 11 and Panametrics EPOCH 2022. The EPOCH 2002 machine produced the best signal-to-noise ratios (at 0.5 MHZ filter) on the 10% and 25% inner diameter notches. The USIP 11 and Mark 1 were adequate, but not as good as EPOCH 2002. The Nortec 131 was found to be inadequate for angle beam examination. With regard to the search units, several interesting obser-vations were made. The search units optimized for the 29 inch diameter calibration block (lower attenuation) also produced optimum results on the 31 inch diameter calibration block (higher attenuation). The second obser-
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vation was that despite attenuation differences between the two blocks, approximately the same results were obtained regarding)the background noise (10% to 20% screen height at the reference sensitivity and the signal-to-noise ratio.
Partial examinations were conducted by CECO at Braidwood Unit 2 on 9 welds of Loop No. 1 using the EPOCH 2002 and the KBA transducers. These prelim-inary examinations showed strong, but intermittent and sometimes continuous signals at the I.D.
These signals, attributed to grain structure and/or j
geometry, were similar to the ones obtained from the 10% inner diameter j
notch.
Based on this developmental work and the preliminary examination of some welds on Braidwood Unit 2, a procedure was written for the preservice examination of weldments in the cast stainless steel components and fittings at Byron Unit 2 and Braidwood Units 1 and 2.
This procedure was used to examine only the case side (s) of the reactor coolant system welds. The welds examined were categorized as follows:
Forged reactor nozzle safe-end-to-cast elbow welds.
Steam generator nozzle-to-cast elbow welds.
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Forged pipe-to-cast elbow, pump or valve welds.
Cast elbow-to-cast pump or valve welds.
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There are approximately 50 welds of these types in each reactor coolant system at Byron Units 1 and 2 and Braidwood Units 1 and 2.
l CECO conducted a plant tour for the meeting attendees pointing out welds
on an elbow to steam generator nozzle, a pump to elbow, a pump to pipe, and valve to elbow that would be ultrasonically examined. CECO also
l performed UT on a valve to pipe weld and a pump to pipe weld. These examinations were conducted in accordance with ASME Section XI, 1977 Edition, Summer 1978 Addenda, Paragraph IWA-2240 and CECO procedure NDT-C-38, Revision 0.
The ultrasonic technicians are trained on calibration blocks and a mock-up of a pipe weld using an Epoch 2002 instrunent and CECO's NDE procedure
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NDT-C-38, Revision 0, prior to perfonning UT on the component welds in the system.
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The NRC inspector observed the training at Byron.
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4.
Observation _. of Ultra _s_o_nic_ Examinations _ _(UT_)
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The NRC inspector observed UT by CECO on a forged pipe to cast elbow weld (Weld No. IRC-01-16) and on a letdown heat exchanger, head to flange weld (Weld No. 1CV04AA). The calibration and the recording was also observed.
i The NRC irspector reviewed the program, procedures, data, material, and personnel qualifications.
No violations or deviations were identified.
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5.
Exit Interview The inspector met with site representatives (denoted in Persons Contacted
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paragraph) at the conclus;on of the inspection. The inspector summarized the scope and findings of the inspection noted in this report. The
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inspector also discussed the likely informational content of the inspection report with regard to documents or processes reviewed by the inspector
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during the inspection. The licensee did not identify any such document /
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f processes as proprietary.
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