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Filler metals used in the nuclear industry
What are the requirements on chemistry of welding metals used in the fabrication of components for nuclear reactors ?
By Peter Stones , IEng MWeldI IWE / EWE
Meet the columnist
Peter Stones
IEng MWeldI IWE / EWE As part of the ESAB Specialty Alloys Group , Peter is technical support for stainless and nickel alloy filler metals . Peter is actively involved with TWI and is a non-executive director of The Welding Institute . Peter worked for Sandvik for 10 years and was Global Product Manager for Sandvik Welding up to 2018 , when ESAB purchased the filler metals business . Email : peter . stones @ esab . com
The welding of metals used in the fabrication of components for nuclear reactors requires special attention to the chemistry of the materials to ensure that the welded joints have the necessary strength , toughness and resistance to corrosion and irradiation . Some of the key requirements for the chemistry of welding metals used in nuclear reactor components include : 1 . Low impurity content : The welding metals must have low levels of impurities such as sulphur , phosphorus , and carbon , as these impurities can weaken the weld joint and make it more susceptible to cracking and corrosion .
2 . High purity : The welding metals must be of high purity to ensure that they do not introduce any contaminants into the reactor coolant or other critical systems .
3 . Controlled composition : The composition of the welding metals must be carefully controlled to ensure that they have the necessary mechanical properties and corrosion resistance .
4 . Radiation resistance : The welding metals must be resistant to radiation damage . This requires that they have a low neutron absorption cross section and do not produce radioactive isotopes when exposed to neutron radiation .
Key requirements for welding metals used in nuclear applications include low impurity content , high purity , a controlled composition , radiation resistance and base metal compatibility .
5 . Compatibility with base metal : As with any welded joint , the welding metals must be compatible with the base metal being welded to ensure that the joint has the necessary mechanical properties and resistance to corrosion . Some examples of metals that may not be suitable for use in nuclear reactors include :
• Aluminium : While aluminium is commonly used in many industrial applications , it is not suitable for use in nuclear reactors due to its low radiation resistance . When exposed to radiation , aluminium can become brittle and prone to cracking .
• Copper : Copper is another metal that is not typically used in nuclear reactors due to its low radiation resistance . Like aluminium , copper can become brittle and prone to cracking when exposed to radiation .
• Carbon steel : Although carbon steel is commonly used in many industrial applications , it is not suitable for use in nuclear reactors due to its low radiation resistance . Carbon steel can become brittle and prone to cracking when exposed to radiation .
• Lead : Lead is commonly used as a radiation shield in many industrial applications . However , it it is not suitable for use in nuclear reactors due to its low radiation resistance . Lead can become brittle and prone to cracking when exposed to radiation .
• Titanium : While titanium is commonly used in many industrial applications , it is not suitable for use
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