Contamination on Building Surfaces

The following is a listing of the USNRC’s “Interim Screening Values of Common Radionuclides for Building Surface Contamination”, as they appeared in the November 18, 1998 edition of the Federal Register (63 FR 64132).  The values shown below are in units of “disintegrations per minute per 100 square centimeter area”.

Hydrogen

• H-3 – 120,000,000

Carbon

• C-14 – 3,700,000

Cesium

• Cs-137 – 28,000

Chlorine

• Cl-36 – 500,000

Cobalt

• Co-60 – 7,100

Iodine

• I-129 – 35,000

Iridium

• Ir-192 – 74,000

Iron

• Fe-55 – 4,500,000

Manganese

• Mn-54 – 32,000

Nickel

• Ni-63 – 1,800,000

Sodium

• Na-22 – 9,500

Strontium

• Sr-90 – 8,700

Sulfur

• S-35 – 13,000,000

Technetium

• Tc-99 – 1,300,000