Some BOSS welds in nuclear power plant are found to contain many defects

such as incomplete fusion

slag

porosity and so on. Causes of BOSS weld defects are investigated and analyzed to be lack of experience for welders

improper implementation and control of the welding process

etc. Based on the conditions of defects and sites

some types of potential solutions（including localized repair

replacement of new pipes or BOSS

Overlay welding

evaluation & monitoring） are put forward to deal with the BOSS weld defects in various situations. Based on the experience

the optimum suggestions of groove angle

welding process and non-destructive inspection of BOSS weld are put forward

to reduce the probability of BOSS weld defects and enhance the safety and economy of the nuclear power plants.