CFR > Title 10 - Energy > CHAPTER I—NUCLEAR REGULATORY COMMISSION > PART 20—STANDARDS FOR PROTECTION AGAINST RADIATION > SUBPART A—General Provisions (§20.1001 to §20.1009) > 20.1005—Units of radioactivity.

20.1005—Units of radioactivity.

For the purposes of this part, activity is expressed in the special unit of curies (Ci) or in the SI unit of becquerels (Bq), or their multiples, or disintegrations (transformations) per unit of time.
(a) One becquerel = 1 disintegration per second (s−1 ).
(b) One curie = 3.7×10 10 disintegrations per second = 3.7×10 10 becquerels = 2.22×10 12 disintegrations per minute.

Code of Federal Regulations

[56 FR 23391, May 21, 1991; 56 FR 61352, Dec. 3, 1991]