which was 30 per cent of tbe world total, and their estimated additional resources hrere put at 254,000 tons, esuivalent to 21 per cent of the total.A/40/5rr Engl i sh Page 6 L2' As at 3l December 1983, 16 nuclear por^rer plants capable of generating 7 r6L5 megahtatts electricat (l'lw(e) ) hrere in operation in developing countries -Argentina, Brazil, China, IO/ India, Pakistan and the Repuhrlic of Korea - anclanother 20 units, with a total capacity of 121962 MW(e) were under construction inArgentina, Brazil, China, Cuba, India, tr{exico, the philippines and the Repubtic ofKorea - g/ Althouqh nuclear pohrer may provide an option to sone developingcountries, its development has been hin<lered by a number of obstacles: the ninimumecononic size of 600 M[f(e) relative to the size of the electricity grids in nostdeveloping countries, g the range of technicar skitls reguired to operate thenuclear facilities safely and efficientlyt the large capital reguirement and thelong gestation perio<i; and the guestion of nuclear fueJ- supply as relatecl topolitical and security considerations by the supplier countries. It would bedifficult to project with confirlence the net additions to the existing nuclear Por{ter capacity of developing countries until the end of the centurv. It has Lreenestimated, bowever, that nuclear pohrer is expected to suppty less than I0 per centof totar electricity in developing countries as a group. L3/ 4. New and renewable sources of enerqv (a) Hylropower
**Analysis**
The text discusses the development of nuclear power in developing countries, highlighting the challenges and limitations faced by these countries in adopting this technology. It also touches on the potential role of nuclear power in meeting the energy needs of these countries. Given the focus on energy and development, it is likely that the text belongs to the categories related to economic development and natural resources and environment.

**Category**
Economic development, Natural resources and environment