strontium-90 [90]Sr

Introduction

One of several radioactive isotopes of strontium.

Occurrence

• by-product of nuclear explosions
• produced during fission of heavy nuclei, such as uranium-235 or plutonium-239

Characteristics

• 1/2life of 29.1 years
• emits beta particles.
  • 'braking' of beta-particles by water or other materials results in emission of X-rays
• radioactivity of Sr-90 is about 138 curies/gram
• it decays it Yttrium-90, also an emitter of beta-particles
• Sr-90 in bone increases risk of osteosarcoma & leukemia
• inhalation of 10 ug of insoluble Sr-90 would result in a high probability of cancer

Uses

• radioisotope thermoelectric generators (RTGs)

More general terms

• strontium [Sr]