Purolite® NRW36Li7

Nuclear Grade Mixed Bed Exchange Resin

Purolite NRW36Li7 is a nuclear grade mixed bed resin especially designed for the removal of radioactive contaminants from primary circuits of nuclear power plants conditioned with lithium 7 isotope. The product is an equilibrium mixture (chemical equivalents) of Purolite NRW100 carefully converted to the high purity lithium 7 isotope form, and Purolite NRW600 which is supplied highly converted to the hydroxide form. The mixture is capable of removing both cationic and anionic contaminants while maintaining the concentration of lithium hydroxide conditioner at near the correct dose level within the sealed circuit. All Purolite nuclear resins are supplied to exacting standards of high purity as given in the specifications below.

APPLICATION

The water circulating in a primary circuit must be clean, and in particular suspended matter must be eliminated. This reduces the risk of corrosion of the fuel rods. In this way contamination of the recirculating water with fission products normally contained in the fuel cans is avoided. To this end, the pH of the circuit is rendered alkaline using preferably lithium seven hydroxide. Natural lithium may be used, but has the disadvantage that tritium can be produced by neutron capture with the small % of Li present in natural lithium. Potassium is also used as a cheaper alternative, but can give some possibilities for transfer of radioactivity. Any polishing mixed bed used in such circuits is preferably loaded with the metal ion used for the pH control.
The cooling water pH is maintained at 7.5-8.5 at reactor temperature. This corresponds to a concentration of 0.2-2 ppm depending upon the boric acid content.

BASIC FEATURES:

Application - Demineralization & Decontamination of Secondary Cooling Circuits
Polymer Structure - Gel polystyrene crosslinked with divinylbenzene
Appearance - Spherical beads
Functional Group - Sulphonic Acid and Type 1 Quaternary Ammonium
Ionic Form as Shipped - 7Li+ / OH-

PRODUCT INFORMATION

Total Capacity, Li7+ Form 1.8 eq/l (39.3 kGr/ft3)
Total Capacity, OH- Form 1.1 eq/l (24.0 kGr/ft3)
Component Gel strong base anion
Cation / Anion Volumetric Ratio 38/62 %
Mean Size Typical 0.65-0.90 mm
Uniformity Coefficient (max.) 1.7
Moisture Content 60 %
Cationic Form (min.) 99.9 %
Impurities Heavy Metals 40 ppm
Impurities Iron (max.) 80 ppm
Impurities Sodium (max.) 30 ppm
Anionic Form 95 %
Anionic Form, Cl- (max.) 0.1 %
Anionic Form, CO3- (max.) 5 %
Anionic Form, SO4- (max.) 0.3 %
Shipping Weight (approx.) 720-750 g/l (45-46.9 lbs/ft3)
Temp Limit, Non-Regenerable Bed 100 °C (212 °F)
Temp Limit, Regenerable Bed 60 °C (140 °F)

MSDS