Resource reuse and sustainability are gradually becoming hot issues nowadays. Waste paper is an important material in paper reproducing. Comparing to wood pulp, waste paper is more energy-saving and environmentally-fr...Resource reuse and sustainability are gradually becoming hot issues nowadays. Waste paper is an important material in paper reproducing. Comparing to wood pulp, waste paper is more energy-saving and environmentally-friendly. Being a top of one paper producing country in the world, China needs a continuous large quantity of waste paper supply. Waste paper strategy＂ is being taken seriously until the ti^ding of paper manufacttlring period. This paper strives to examine the waste paper circle and the changes of waste paper resource strategy in China nowadays by doing both amount and price analysis on waste paper trade. It is found that China now strives to promote a sustainability of waste paper resource reuse by drawing down waste paper import, increasing domestic reuse and increasing import channels and categories.展开更多
A burnup calculation has been performed to evaluate heavy rare earth （terbium--Tb, dysprosium--Dy） production in spent gadolinium oxide （Gd203） installed as a BP （burnable poison）. Each amount of Tb and Dy produ...A burnup calculation has been performed to evaluate heavy rare earth （terbium--Tb, dysprosium--Dy） production in spent gadolinium oxide （Gd203） installed as a BP （burnable poison）. Each amount of Tb and Dy production derived from the BP has been about 30-40 times larger than those created in FP （fission products）. Required cooling time to achieve exemption level on radioactivity concentration produced Tb and Dy derived from the BP are much shorter （BP-Tb： 7.9y, BP-Dy： 〈 0.1y） than those created in FP （FP-Tb： 3,616y, FP-Dy： 6.9y）. However, the BP is mixed homogeneously with UO2 pellet in current nuclear fuel system of LWRs （light water reactors）, and hence mixing of FP cannot be not avoided. In such a mixture case, the required cooling time of recovered Tb will become 2,653y and that of recovered Dy be 4.8y. For this reason, recovered Tb is unlikely to be resource for utilization, while recovered Dy must be the resource provided the precise separation from the other FP.展开更多
文摘Resource reuse and sustainability are gradually becoming hot issues nowadays. Waste paper is an important material in paper reproducing. Comparing to wood pulp, waste paper is more energy-saving and environmentally-friendly. Being a top of one paper producing country in the world, China needs a continuous large quantity of waste paper supply. Waste paper strategy＂ is being taken seriously until the ti^ding of paper manufacttlring period. This paper strives to examine the waste paper circle and the changes of waste paper resource strategy in China nowadays by doing both amount and price analysis on waste paper trade. It is found that China now strives to promote a sustainability of waste paper resource reuse by drawing down waste paper import, increasing domestic reuse and increasing import channels and categories.
文摘A burnup calculation has been performed to evaluate heavy rare earth （terbium--Tb, dysprosium--Dy） production in spent gadolinium oxide （Gd203） installed as a BP （burnable poison）. Each amount of Tb and Dy production derived from the BP has been about 30-40 times larger than those created in FP （fission products）. Required cooling time to achieve exemption level on radioactivity concentration produced Tb and Dy derived from the BP are much shorter （BP-Tb： 7.9y, BP-Dy： 〈 0.1y） than those created in FP （FP-Tb： 3,616y, FP-Dy： 6.9y）. However, the BP is mixed homogeneously with UO2 pellet in current nuclear fuel system of LWRs （light water reactors）, and hence mixing of FP cannot be not avoided. In such a mixture case, the required cooling time of recovered Tb will become 2,653y and that of recovered Dy be 4.8y. For this reason, recovered Tb is unlikely to be resource for utilization, while recovered Dy must be the resource provided the precise separation from the other FP.
