Determination of microgram amounts of cobalt in sodium metal: 2-Nitroso-r-naphthol spectrophotometric method
✍ Scribed by Louis Silverman; Rachel L. Seitz
- Publisher
- Elsevier Science
- Year
- 1959
- Tongue
- English
- Weight
- 312 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0003-2670
No coin nor oath required. For personal study only.
✦ Synopsis
I>E'~EI~MINATION OF MICROGRAM AMOUNTS OF COBALT IN SODIUM ME-l-AT,*
'l'lic valuable propcrtics of pin-c sodium as coolant in certain types of atomic cncrgy reactors arc well known. After a calculated long-term opcra.tionul period, the reactor must hc shut down and the fuel rods cxchangccl. During the operational period the sodium and its impurities arc subjected to irradiation and a "cooling"
or "clecay" period is forcsccn at the shutdown. One of tile many possible clcmcnts prcscnt in the sodium which could cnforcc im unusually long cooling period is cobalt, l>t!CilUSL! of the likely prcscncc of a long-lived cobalt isotope. Calculations show that not more tllan 2 p.p.m. of cobalt arc permissible in the sodium, in order to prevent an uncconomitally long cooling J>eriocl bcforc the irradiated sodium can bc safely transportctl and hancllccl.
Scvcral colorimctric mcthocls for analyzing small amounts of cobalt were csaminctl. 'I'hc reagent, z-nitroso-r-naphtliol, appcarccl to bc the most applicable and it is this reagent which is usccl. A tcchniquc similar to that cmploycd by ALMOND'
for dctcrmining cobalt in soils was clcvelopccL 'I'hc cobalt forms a comples with the rcagcnt at a prr of 4 to 8.5. Other impurities such as ferric iron, copper and nickel cause no intcrfcrcncc since the ferric iron clots not complcs at this prr and the copper and nickel coiiiJ~lcscs prcscnt in small amounts, arc rctiiovccl by washing.