Separation of Boric Acid from PWR Waste by Volatilization During Evaporation

Radiometric techniques for the detection and assessment of tritium in aqueous media - a review

“…Commercial reactors produce about 2 grams of 3 H per year (equivalent to 714 TBq), with the ternary fission contribution incorporated predominantly into the fuel pellets and/or cladding surrounding the fuel elements. Activation of 10 B, used in control rods and in chemical shim necessary to quench reactivity in light water reactors, produces 3 H directly or indirectly via 7 Li, see Equation 2 [11], and further via lithium hydroxide used to control pH [12], 10 B + n → 3 H + 2 10 B + n → 7 Li +  7 Li + n → 3 H +  Eq. 2 Thus, the management and treatment of cooling waters leads to the production of tritium, which can be upwards of six times higher in PWRs than BWRs [13].…”

Isobaric Heat Capacity of Boric Acid Solution

“…4 Recovery and recycling of boric acid are necessary for environmental reasons and for reducing the operational costs of nuclear power plants. 5 The evaporation method is a simple but technically and economically viable method for separating boric acid. 6 Basic thermophysical properties, such as heat capacity and viscosity, are indispensable for the design of the recovery system.…”

“…For example, a 10 6 kW power unit in the Daya Bay Nuclear Power Plant discharges 132 m 3 liquid waste (the 10 B concentration of boric acid solution is 0.648 mol/kg) preprocessed or 23 m 3 concentrated liquid waste (the 10 B concentration of boric acid solution is 3.700 mol/kg) every year . Recovery and recycling of boric acid are necessary for environmental reasons and for reducing the operational costs of nuclear power plants . The evaporation method is a simple but technically and economically viable method for separating boric acid .…”