United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 83-71: Defects in Load-bearing Welds on Lifting Devices for Vessel Head and Internals

                                                            SSINS No.: 6835 
                                                            IN 83-71       

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                    OFFICE OF INSPECTION AND ENFORCEMENT
                           WASHINGTON, D.C. 20555
                                     
                              October 27, 1983

Information Notice No. 83-71:   DEFECTS IN LOAD-BEARING WELDS ON LIFTING 
                                   DEVICES FOR VESSEL HEAD AND INTERNALS 

Addressees: 

All holders of nuclear power reactor operating licenses (OL) or construction
permits (CP). 

Purpose: 

This information notice provides notification of the potential for failure 
of reactor vessel head and internals lifting devices manufactured by Babcock
and Wilcox Company. It is expected that addressees will review the 
information provided here for applicability to their facilities. No specific
response or action is required. 

Description of Circumstances: 

A lifting device for the vessel head and internals supplied to Florida Power
Corporation by Babcock and Wilcox was found to have weld defects in 
load-bearing welds. If the welding defects were to go uncorrected, they 
could jeopardize the capability of the lifting system to safely handle 
safety-related components within reactor compartments. 

The subject lifting device was fabricated to industry standards. However, a 
subsequent regulatory requirement, NUREG-0612 requires that the lifting 
device be tested in accordance with ANSI N14.6 on the basis that it is to 
carry heavy loads over safety-related systems. 

Florida Power Corporation committed to perform appropriate non-destructive 
examination (NDE) on the device as required. Results of the NDE (magnetic 
particle) revealed four indications in welds on the tripod, one on the 
turnbuckle, and one on the latchblock. In addition, a visual examination 
revealed that several welds showed undercut, porosity, and cold lapping. 
Defects found were considered potential safety hazards if not repaired and 
suggest that the industry standards used were inadequate to meet the service
intended. As a remedy, the welds on the tripod and the latchblock were 
repaired and the turnbuckles were replaced with a solid unwelded model. 
Subsequent to repairs, the lifting device was qualified for use as 
designated by performance of NDE and load testing in accordance with ANSI 
N14.6 as required by NUREG-0612. Although 
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                                                           IN 83-71        
                                                           October 27, 1983 
                                                           Page 2 of 2     

load testing in accordance with ANSI N14.6 satisfies the letter of NRC 
requirements, prudence would indicate the desirability, of rigorous NDE, to 
improve confidence that lifting and handling systems, when tested, will not 
fail. 

The example cited was furnished by Babcock and Wilcox, but the NRC concern 
applies to both standard and custom elements of heavy-load-handling systems.

If you have any questions regarding this matter, please contact the Regional
Administrator of the appropriate NRC Regional Office, or this office. 


                                   Edward L. Jordan Director 
                                   Division of Emergency Preparedness 
                                     and Engineering Response 
                                   Office of Inspection and Enforcement 

Technical Contact:  J. B. Henderson, IE
                    (301) 492-9654

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