IR 05000269/1981024
| ML15224A475 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 10/30/1981 |
| From: | Economos N, Herdt A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML15224A471 | List: |
| References | |
| 50-269-81-24, 50-270-81-24, 50-287-81-24, NUDOCS 8201270339 | |
| Download: ML15224A475 (6) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION REGION 11 101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 Report Nos. 50-269/81-24, 50-270/81-24, 50-287/81-24 Licensee:
Duke Power Company 422 South Church Stree Charlotte, North Carolina Facility Name:
Oconee Docket Nos. 50-269, 50-270, 50-287 License Nos. DPR-38, DPR-47, DPR-55 Inspection at Oconee site near Clemson, South Carolina at the Babcock & Wilcox Lynchburg Research Center, Lynchburg, Virginia, and at IE Headquarters, Bethesda, Maryland Inspector:
_//244 P,/
N. Econo s
/Date/Signed Approved by:
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W A. R. Herdt, Section Chief Date Signed Engineering Inspection Branch Engineering and Technical Inspection Division SUMMARY Inspection on October 2 to October 9, 1981 Areas Inspected This routine, unannounced inspection involved 34 inspector-hours on site at IE Headquarters and at B&W's Lynchburg Research Center (LRC) in the areas of Unit 1 ten year inservice inspection of the reactor pressure vessel and other Class 1 and 2 components; core barrel assembly thermal shield broken bolts; and Once Thru Steam Generator (OTSG)
tube repair - Unit Results Of the three areas inspected, one violation was identified in one area:
(Viola tion -
Failure to Verify Qualifications of NDE Personnel -
paragraph 6).
No deviations were identifie PDR ADOCK 05000269
REPORT DETAILS 1. Persons Contacted Licensee Employees
- J. E. Smith, Station Manager R. J. Brackett, Senior QA Engineer Jack Crowe, QA, NDE/Welding T. E. Cribbe, License Engineer
- G. Rothenburger, Support Engineer, Mechanical Maintenance W. W. Gallman, Mechanical Maintenance Support Engineer B. Millsaps, Assistant Engineer
- T. C. Mathews, Technical Specialist Other Organizations Babcock and Wilcox, Nuclear Power Generation Division (NPGD)
H. W. Stoppelmann, ISI Coordinator C. Pryor, Manager Planning Operations G. S. Clevinger, Manager, Nuclear Materials Technology, LRC R. V. Straub, Service Manager, Operating Plant Services K. Moore, Principal Engineer, Materials & Technology George Hayner, Research Specialist NRC Resident Inspector
- W Orders D. 0. Myers
- Attended exit interview 2. Exit Interview The inspection scope and findings were summarized on October 7, 1981 with those persons indicated in paragraph 1 abov The inspection finding listed below was discussed in detai No dissenting comments were received from the license (Open) Violation 269/81-24-01: "Failure to verify qualifications of NDE personnel" - paragraph. Licensee Action on Previous Inspection Findings Not inspecte.
Unresolved Items Unresolved items were not identified during this inspectio.
Independent Inspection Efforts a. -Core Barrel Assembly Thermal Shield Bolts Broken (LER 269/81-11)
As a followup to the work effort reported in RII report No. 50-269/
81-16 the inspector met with cognizant B&W personnel on October 2, 1981 at the Lynchburg, Research Center (LRC),
in Lynchburg, Virginia, and discussed more recent results of the ongoing investigation into this problem. At this point, the investigation had shown that the bolts in the Oconee 1 vessel were procured from Valley Todeco and Standard Press Steel. All the broken bolts were supplied by Valley Todec The Valley Todeco bar stock material was produced by Universal Cyclops from heat number G-5594-K1. Other facilities with bolts in the lower thermal shield made from the same bar stock material included Crystal River-3, Arakansas-1, Rancho Seco and Davis-Bess Unlike all the other bolts used in the Oconee-1 internals, these bolts were produced from cold worked bar stock which had been cold reduced 40 to 50%, prior to a hot heading operatio All the other bolts were produced from solution annealed materia A metallographic examination disclosed that the transition zone between the shank and the hot upset bolt head contained a band of pronounced grain growth, which extended into the fillet area between the head and bolt shank. It should be noted that, in general, the bolts failed in or near this are The condition described above was not evident in the bolts used on other bolted joints of the internals that were examined, which included the upper thermal shield bolting and one of the two bolts found to be intact in the lower thermal shield connectio The inspector, with the aid of a metallograph, examined the metallo graphic samples prepared from archival and broken bolts and ascertained the condition described abov Photographs of fracture surfaces depicted by SEM examination, records of chemical and mechanical proper ties and other related data were reviewed. Thus far, the examination has shown the failure to be the result of intergranular cracking with evidence of grain boundary corrosion attack as the apparent dominant mode of failure. A portion of the fracture surface exhibited evidence of a transgranular fracture mechanism associated with fatigue striation and/or crack arrest marks. The latter probably occurred in the later stages of the bolt failur B&W disclosed that further confirmatory laboratory examinations are underway in an effort to better define the role of the duplex grain structure transition in the bolt failur On October 9, 1981 inspectors N. Economos and A. R. Herdt attended a meeting at NRC Headquarters which was requested by NRC in order to discuss with DPC, and other B&W owners, the site specific and generic problems resulting from the failure of the Oconee-1 thermal shield bolt The agenda and topics discussed were as follows:
(1)
Describe the differences between the modifications made to the-Oconee 1 thermal shield and other Oconee units including such items as bolting material and fabrication, modification procedures (shop or field), installation and preloading procedure (2)
Provide the details of the bolt failure investigation available to date (metallogrpahy, etc.), describe the failure mode and describe the condition of the other bolt (3)
Describe the differences in hydraulic loads between the inside and outside surfaces of the thermal shiel (4)
Describe the Loose Parts Monitoring System at Oconee 1 and explain why it was ineffective in detecting these broken bolts and its sensitivity to thermal shield vibrations (i.e., is it sensitive such to preclude damage).
(5) Provide additional discussion regarding the missing guide block, dowel, bolt and washer investigatio (6) Describe any planned inspection of Oconee 2 including sample size, inspection procedures and resolution for TV inspection After hearing the B&W/DPC presentation on the broken bolts and the planned corrective action (new bolt material and design) for Oconee 1, the NRC staff concluded that more time was needed to review the proposed bolt design changes. The NRR representative stated that the generic aspects of the problem will be evaluated after the staff has had the opportunity to review the results from Crystal River 3 and Oconee 3 inspection On October 6-7, 1981 the inspector observed the work effort by B&W to remove the twelve remaining bolts from the thermal shield to lower grid connection. Equipment failure precluded removal of these bolts at this tim OTSG B Tube Leak Repair, Unit-2 On September 18, 1981, DPC informed R:II that a leak had been detected in OTSG"B".
The unit was shut down and the leaky tube was identified (tube 77-2)
and repaired on September 30, 198 Results of an eddy current (EC) examination indicated the tube may be cracked circumferentially which could account for its high leak rate of 30 GP An adjacent tube (77-3) showed evidence of a 30% tube wall indicatio In response to questions and discussions on the subject, the cognizant DPC engineer stated the above tubes were EC inspected on March 15, 1980 and found acceptable. A total of 26 OTSG tubes have been removed from service in OTSG"B" thus far. The controlling code for this repair was identified asSection XI (74S75) Article IWA-400 Structural adequacy (design and manufacture of the stabilizer) meets ASME III (74576)
qirements The following documents/records were reviewed. Eddy Current inspection form 600 page 10 3/15/80; NSM-1892 Installation of Stabilizer field change authorization FCA-197-00 and FCA 94-3647-00, field weld data sheet 1-299-13 Rev. 3. Other QA/QC records- -reviewdincluded: filler -metal receipt inspection reports, material certifications and welder issue slips; welder and inspector qualifications; stabilizer and weld cap receipt inspection reports and material certificatio Within the areas inspected no violations or deviations were identifie.
ISI Data Review and Evaluation (Unit 1).
This work effort was a followup to that reported in R:II report 50-269/81-1 ASME Section XI (74S75)
as required by 10CFR50.55(a)
paragraph (g) is the governing code for this activit Records from areas examined during this outage were reviewed to ascertain whether they contained references to examination results and data sheets; examination equipment data; calibration data sheets; evaluation of data; extent of examination; deviations from programmatic requirements; dispostion of findings; and identification of NDE materia Records selected for the above work effort were as follows:
COMPONENT/
WELD AREA/
INSPECTION FIGURE PART METHOD B1.18.004 5-W60, Base to CRDM UT-00, 450, limited scan Motor Tube Motor Tube Side B1.18.005 20-W60 Base to CRDM UT-00, 450, limited scan Motor Tube Motor Tube Side B1.18.006 25-W60 Base to CRDM UT-0 0, 450, limited scan Motor Tube Motor Tube Side B1.18.007 5 Base Tube CRDM UT-0 0, 450, limited scan Motor Tube From SS side One geometric indication Acceptance per ASME Section III NB5000 (74S75)
B1.18.008 CRD-20 UT-0 0, 450, limited scan from SS side B1.18.009,9A CRD-25 UT-0 0, 450, limit scan from C.S. side B1.18.011 Peripheral CRDM UT-0 0, 450, limit scan extension to CAP from C.S. side
COMPONENT/
WELD AREA/
INSPECTION FIGURE PART METHOD (Continued)
C1.04.001 Upper Manway UT-0 0 STUDS ID #162 2 studs C2.1.361 DOC1F, 03-03-X24 RT C2.1.359 DOCIF, 03-03-44B RT C2.1.329 DOC1F 03-03-X4 RT-0-1 rejected and repaired, RT accept 9/9/81 B5.006.002 Reactor Coolant RT; reviewed six Pump, 1RcP-A2 of 17 films, positions 0 size 51" X 56" diameter to 6 Areas reviewed also included system calibration for possible excessive deviation between initial and final calibrations; documentation of exam ination data for completeness and accuracy with respect to recordable indications; evaluation of data by qualified personnel and consistency with procedure/code requirements; description of inaccessible areas and corre lation between PSI and ISI data as applicabl Within these areas the inspector noted that one of the Level II UT examiners had been certified to that level on September 9, 1981 and arrived at Oconee on October 1, 1981 without his certification By observation/discussions and record review the inspector ascertained that the aforementioned indi vidual performed code required ISI examinations (UT) as a Level II examiner on the 6th and 7th of October, 1981. However, when the inspector asked to review the examiner's certification, B&W and the licensee representative stated that this document was not on site and not available for review but could be made available upon reques In discussion that followed, the inspector pointed out that IWA-1400 requires the owner to verify the quali fication of personnel who perform code required examination However, under these circumstances, the inspector stated that it was difficult if not impossible to see how this had been done for this examine This failure to comply with code requirements was considered as a violation against 10 CFR 50.55(a), (g) as implemented by the technical specification paragraph 4.2. This violation was identified as item 269/81-24-01; Failure to Verify the Qualification of NDE Personnel."
Except as noted above no other violations or deviations were identified.