Chlorine is usually present at low concentrations in reactor materials
and thermal neutron activation of Cl-35 produces Cl-36, which has a l
ong half-life and is a radionuclide of significance in nuclear waste d
isposal. This paper describes a radiochemical method that has been dev
eloped to measure low concentrations of CI in reactor stainless steels
, so that the amount of Cl-36 in radioactive wastes can be estimated,
The method is based on the irradiation of a 1 g sample in a thermal ne
utron nux of 10(16), m(-2) s(-1), followed by dissolution in HNO3 with
the addition of stable KCI carrier/tracer. The Cl is precipitated as
AgCl, and the recovery is measured gravimetrically. The Cl-38, which h
as a half-life of 37 min, is measured with gamma-ray spectrometry, The
entire process, from irradiation to the end of counting, takes simila
r to 1.5 h. The recovery is near-quantitative, and the detection limit
for Cl in most stainless steels is below 1 mg/kg.