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In this work, the effect of inadvertent control rod withdrawal on the thermal-hydraulic parameters of VVER-1200 type nuclear power reactor has been investigated. Personal Computer Transient Analyzer (PCTRAN) has been used to simulate the transient responses associated with the situation. An attempt has been made to find out the maximum amount of positive reactivity that may be inserted instantaneously without causing serious damage to any of the essential reactor components. Four instantaneous positive reactivity insertion case studies have been performed in the range of 2.5-10% Δk/k in order to identify the limiting condition for ensuring safety of the nuclear facility. Results show that for all the cases, prompt criticality is observed due to positive reactivity insertion higher than 0.66% Δk/k. For positive reactivity insertion up to 7.5% Δk/k, the maximum core thermal power is observed to be less than 160% of the rated core thermal power. The peak cladding temperature is observed to be less than 800 o C with no clad failure. However, for 10% Δk/k reactivity insertion, core thermal power has been observed to reach nearly 360% of the rated core thermal power. Also, a 76% probability of cladding failure is recorded due to peak cladding temperature reaching nearly 1400 o C. To identify the maximum limit of instantaneous positive reactivity insertion, a "Factor of Safety" based analysis has been conducted. Results from the analysis reveal that maximum limit is around 8.8% Δk/k. This finding is supported by the results from further simulations.

This paper empirically investigates the major driving forces of remittance inflow in Bangladesh. Using annual data over the period from 1977 to 2011 the paper concludes that gross domestic products of host country and domestic country, exchange rate, petroleum price and skill of labour significantly influence remittance inflow in Bangladesh. One finding of the research is that skilled labour force rather sends smaller amount of remittance to the home country than the unskilled labour. This is due to the fact that skilled people do not maintain close tie with the home country because they often take their families with them to foreign countries where they work. Because of narrow opportunities, unskilled labour cannot take their families with them and hence send money to their families. The study also identifies the reason behind migration of manpower from Bangladesh to foreign countries. Presence of surplus labour, slim job opportunity, unfavourable working environment, poor wage rate, inadequate social security and political instability largely induce people to migrate abroad.