ML20008D977
| ML20008D977 | |
| Person / Time | |
|---|---|
| Issue date: | 08/25/1980 |
| From: | Mcneill W, Whitesell D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20008D975 | List: |
| References | |
| REF-QA-99900001 NUDOCS 8010240016 | |
| Download: ML20008D977 (6) | |
Text
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(L.))
U.S. NUCI. EAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT REGION IV-Report No. 99900001/80-02 Program No. 51500 Company:
Babcock and Wilcox Company Nuclear Materials Division P. O. Box 1260 Lynchburg, Virginia 24505 Inspection Conducted: August 4-8, 1980 Inspector:
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l W. M. McNeill, Contractor Inspector
/ Date ComponentsSection I Vendor Inspection Branch
/'
Approved b
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- he D. E. Whitesell, Chief Date ComponentsSection I Vendor Inspection Branch Summa:,/
Inspection on August 4-8, 1980 (99900001/80-02)
Areas Inspected:
Implementation of 10 CFR 50, Appendix B, including fuel hold down spring failures; fuel assembly fabrication:
and action on previous inspection findings. The inspection involved twenty-six (26) inspector-hours on sitt by one (1) NRC inspector.
Results:
In the three (3) areas inspected no apparent deviations or unresolved items were identified.
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DETAILS SECTION A.
Persons Contacted
- R. A. Alto, Manufacturing Manager
- J. L. Brown, Data Evaluation, Supervisor R. E. Davidson R. V. DeMars, Unit Manager Fuel Design
- J. Ficor, Manager QC
- R. J. Flicker, Supervisor QC Engineer T. E. Ford, Manufacturing Supervisor
- G. L. Garner, Design Engineer
- A. F. Garnier, Manufacturing Engineer
- K. L. Harris, Chief Inspector
- W. F. Heer, Operations Manager
- L. T. Lee, Manufacturing Foreman W. L. Tibbs, Surveillance Specialist
- Denotes those attending the exit interview.
B.
Action on Previous Inspection Findings 1.
(Closed) Deviation (Report No. 80-01):
Pellet boxes were stamped as sampled when they were not sampled.
Inspection of the sampling activities found that the procedures were being followed.
All boxes labeled sampled were found to have been sampled.
2.
(Closed) Deviation (Report No. 80-01): A tray of 50 fuel rods was found in which approximately 15 were not identified as nonconforming.
The nonconforming control procedure has been changed.
A locked storage and a log book are now used. No rods were found which did not have their status identified.
3.
(Closed) Deviation (Report No. 80-01):
The amperage limits were not included in the fabrication procedure and the voltage limits were exceeded in welding.
Welding was inspected and found to be performed in accordance with the parameter sheets.
A complete review is under-way of all types of welding to assure that parameter sheets are accurate and complete.
4.
(Closed) Unresolved Item (Report No. 80-01):
The records of the qualification of one welder could not be found.
The welder in question has been requalified. The original records could not be found although other records do show that a qualification had been performed.
In the course of closing this unresolved item, the following new item was noted.
I_
3 Followup Item Procedures MA 498 and MA 202 address welder qualification.
Both procedures allow welder qualification of one type of weld joint by welding on a dif-ferent type weld joint.
For example MA 498 allows qualification of a spot veld (tack weld) of spider to hub (control rod assembly) and plug weld of pins (control rod assembly) by performance of a spot weld of the control rod lock nuts. This problem was identified by B&W before the inspection in the close out of the previous unresolved item.
B&W has agreed to review this question by the next inspection.
Some procedural revision would appear in order in this case.
C.
Fuel Assembly Fabrication Controls 1.
Objectives The objectives of this area of the inspection were to verify that:
Quality control procedures and practices relating to final a.
fuel assembly operations are sufficient to give assurance that the final assembled fuel bundle meets specifications and con-tractural requirements.
b.
The manufacturer's system is capable of producing quality fuel assemblies.
2.
Method of Accomplishment The preceding objectives were accomplished by:
Review of the Commerical Nuclear Fuel Plant Quality Assurance a.
Manual, Revision 10, Sections 5, Instructions, Procedures, and Drawings; 10, Inspection; 14, Inspection Test and Operating Status, which established the general requirements for controls of fuel assemblies.
b.
Review of the Contract Information Sheets for project 23A and the following specification and drawings:
Applicable Documents List, ADL-21-1005 386-05; Special Instructions, 1118951-00, 1118952-00, 0023-00, 0106-01, l
and 0125-00; Mark B Fuel Assembly General Arrangement Drawing, 02-1183-05; Fuel Assembly Quality Requirement Matrix, 48-1401-01 and
. Mark B Series Fuel Assembly, 08-1183-05.
c.
Review of the following inspection procedures:
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4 End Grid Fastening Insert Metallagraphic Sectioning Steel MK B or MK C, QC-901, Addenda IV, Revision 1; Fuel Assembly Final Inspection Mark B & C, QC-803, Revision 2; Fuel Assembly Guide Tube Alignment Inspection Mark B & C, QC-807, Revision 1, and Fuel Assembly Envelope Inspection Mark B & C, QC-809, Revision 1.
d.
Inspection of assembly operations and inspections under way currently.
This inspection included review of the following:
Insert Weld Met Lab Reports; Gage Control Cards and their Miscellaneous Inspection Reports; Fuel Assembly Envelope Inspection Reports; Mark B Fuel Spacer Grid Orientation Assembly Final Visual Inspection; Fuel Assembly Release and Stacking Sheets; Mark B Fuel Assembly Final Inspection Reports; Route Cards /and Computer printouts of fuel rod spacings.
3.
Findings a.
Deviations None.
b.
Unresolved Items None.
D.
Fuel Holddown Spring Failures 1.
Objectives The objectives of this area of the inspection were to verify that:
a.
A study had been made of recent failures of fuel holddown springs and that the causes of failures, generic consideration, and prevent action have been addressed.
b.
An independent verification of the accuracy and completeness of the
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2.
Method of Accomplishment Review of three (3) interim reports LR:80:7512:01, LR:80:7512:02 a.
and LR:80:7523:01. Discussion of the reports with design and manufacturing personnel.
b.
Inspection of the material test reports of the two (2) heats identified as defective and two others.
Inspection of the stacking sheets, and material logs of receiving inspection.
Inspection the recent purchase order and associated quality and engineering requirements.
3.
Findings a.
Deviations None.
b.
Unresolved Items None.
c.
Comments During a recent reload outtage of Davis Besse, a broken fuel holddown spring was observed.
A Preliminary Notification (PNO-III-80-95) was issued.
The fuel holddown spring retains the fuel assembly against the lower grid plate while providing for radiological and thermal growth and relaxation and flow induced vibration.
The springs are coils of approximately 1/2" wire about 6" high and 5" wide and are preloaded to approximately 500 pounds. After further investigation at Davis Besse two (2) additional broken springs were found in the discharged fuel and four (4) in the operating fuel in the core.
B&W issued a bulletin to utilities with their Mark B type fuel to investigate their fuel.
Oconee III site reported three (3) failures and Crystal River and Oconee I one each.
A study of some failed springs and two (2) unfailed springs was begun.
In addition, archival samples were studied of ten (10) heats of materials.
The failed springs indicated that the mechanism of failure was fatigue induced cracking promulated to failure by stress corrosion.
In general, the start of cracking was cross granular and later inter granular.
l This was substantiated by the 10 archive heats studied.
The heats which showed a high incidence-of failure were highly correlated with:
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-(1) An outer rim of coarse grain in its metallographic cross
- section, (2) Failure of the Rising Load test (MIL-N-24114B), and (3) Failure of the othophosphoric etch test.
The later tests measure resistance to stress corrosAon. These heats were specifically 72F7 and 67C4. A repair program was completed in which springs of these heats were removed from operating fuel assemblies and replaced. Of the fifteen (15) heats of material received by B&W, ten (10) heats have been tested, the remaining five heats have not been tested because of the lack of archive samples.
Two (2) of these five (5) have been discharged. One heat can be found in mostly operating fuel and two (2) of the five in mostly discharged fuel. The majority of the fifteen (15) heats was supplied by one wire manu-facture and one spring fabricator.
It was verified during this inspection that all the springs received were accounted for by B&W. All were used in the projects (co'res) in question.
In addition, the corrective action of imposing a minimum grain size on new orders was verified.
E.
Exit Interview The inspector met with management representatives (denoted in paragraph A) at the conclusion of the insp;ction on August 8, 1980.
The inspector summarized the scope and findings of the inspection. The management representatives had no comment in response to each item discussed by the inspector.
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