Half-Value and Tenth-Value Layers for X-ray and Gamma ray Radiation

Tables showing the Half-Value (HVL) and Tenth-Value Layer (TVL) for penetration of x-rays and gamma rays through shielding material. The data is presented for broad beam conditions with heavily filtered x-rays and for gamma radiation. Despite its age (1971 vintage) may of the values are recognisable today, appearing in modern IAEA / NCRP radiation shielding data. Use with caution (and speak to a Radiation Protection Adviser).

The definition of 'safe' is not strictly an engineering term; it's a societal term. Does it mean absolutely no loss of life? Does it mean absolutely no contamination with radiation? What exactly does 'safe' mean?

– Henry Petroski -