Analysis of 99Mo Production Capacity in Uranyl Nitrate Aqueous Homogeneous Reactor using ORIGEN and MCNP

99mTc is a very useful radioisotope in medical diagnostic procedure. 99mTc is produced from 99Mo decay. Currently, most of 99Mo is produced by irradiating 235U in the nuclear reactor. 99Mo mostly results from the fission reaction of  235U targets with a fission yield about 6.1%. A small additional amount is created from 98Mo neutron activation. Actually 99Mo is also created in the reactor fuel, but usually we do not extract it. The fuel will become spent fuel which is a highly radioactive waste. 99Mo production system in the aqueous homogeneous reactor offers a better method, because all of the 99Mo can be extracted from the fuel solution. Fresh reactor fuel solution consists of uranyl nitrate dissolved in water. There is no separation of target and fuel in an aqueous homogeneous reactor where target and fuel become one liquid solution, and there is no spent fuel generated from this reactor. Simulation of the extraction process is performed while reactor in operation (without reactor shutdown). With an extraction flow rate of 3.6 L/h, after 43 hours of reactor operation the production of 99Mo is relatively constant at about 98.6 curie/hour./hour.Received: 11 January 2014; Revised: 18 February 2014; Accepted: 28 February 201

Optimal pumping schedule for the Ganges-Kobadak irrigation system

In Workshop on Applied Research for Increasing Irrigation Effectiveness and Crop Production, BARC, Farmgate, Dhaka, 8-9 October 199

Analysis of 99Mo Production Capacity in Uranyl Nitrate Aqueous Homogeneous Reactor using ORIGEN and MCNP

99mTc is a very useful radioisotope in medical diagnostic procedure. 99mTc is produced from 99Mo decay. Currently, most of 99Mo is produced by irradiating 235U in the nuclear reactor. 99Mo mostly results from the fission reaction of 235U targets with a fission yield about 6.1%. A small additional amount is created from 98Mo neutron activation. Actually 99Mo is also created in the reactor fuel, but usually we do not extract it. The fuel will become spent fuel which is a highly radioactive waste. 99Mo production system in the aqueous homogeneous reactor offers a better method, because all of the 99Mo can be extracted from the fuel solution. Fresh reactor fuel solution consists of uranyl nitrate dissolved in water. There is no separation of target and fuel in an aqueous homogeneous reactor where target and fuel become one liquid solution, and there is no spent fuel generated from this reactor. Simulation of the extraction process is performed while reactor in operation (without reactor shutdown). With an extraction flow rate of 3.6 L/h, after 43 hours of reactor operation the production of 99Mo is relatively constant at about 98.6 curie/hou

Farm-level effects of irrigation system design and operation problems

In Hydraulics Research Limited, IIMI, Overseas Development Administration, and Sri Lanka, Irrigation Department, Irrigation Design for Management - Asian Regional Symposium, Kandy, Sri Lanka, 16-18 February 1987 (pp. 1-20). Wallingford, UK: Hydraulics Research LimitedThe paper discusses the interrelationship of design (and construction), operation, and performance of irrigation systems. Specifically, it (1) describes the farm-level effects of design (and construction) and operation on the performance of irrigation systems; (2) identifies the factors leading to ineffective use of farm-level facilities by farmers; and (3) recommends additional criteria for the design and operation of irrigation systems. Arguments from Philippine case studies that evaluated alternative designs of farm-level facilities and approaches to improve equity in water allocation and distribution in a modern traditionally designed run-of-the-river, reservoir-backed, and pump-based irrigation systems are used.The general conclusion is that in both the traditional and modern systems, improvements in water management at the main system can improve water distribution equity and increase irrigated area as well as crop yield. But improved management in the main system often becomes difficult, if not impossible, because of some technical inadequacies due to deficient irrigation system design and construction

Producing More Rice with Less Water from Irrigated Systems

Over the past decade, we have witnessed a growing scarcity of and competition for water around the world. As the demand for water for domestic, municipal, industrial, and environmental purposes rises in the future, less water will be available for agriculture. But the potentials for new water resource development projects and expanding irrigated area are limited. We must therefore find ways to in-crease the productivity of water used for irrigation. This paper reviews the literature on irrigation efficiency and on the potential for increasing the productivity of water in rice-based systems. It identifies the reasons for the wide gap between water requirement and actual water input in irrigated rice production systems and discusses opportunities for bridging the gap both on-farm and at the system level. The potentials for water savings in rice production appear to be very large. But we do not know the degree to which various farm and system interventions will lead to sustainable water savings in the water basin until we can quantify the downstream impact of the interventions. Studies on the economic benefits and costs of alternative interventions are also lacking. Without this additional information, it will be difficult to identify the potential benefits and the most appropriate strategies for increasing irrigation water productivity in rice-based systems. This paper emphasizes the need for integrating various water-saving measures into practical models and for conducting holistic assessments of their impact within and outside irrigation systems in the water basin

Technology and management practices for increasing water productivity in rice-based systems: Growing more rice with less water

In Korean National Committee on Irrigation and Drainage; Rural Development Corporation, Water in 2000's: Efficient operation and maintenance and management of Irrigation Systems. Seoul, Korea: Korean National Committee on Irrigation and Drainag

Producing more rice with less water from irrigated systems

Over the past decade, we have witnessed a growing scarcity of and competition for water around the world. As the demand for water for domestic, municipal, industrial, and environmental purposes rises in the future, less water will be available for agriculture. But the potentials for new water resource development projects and expanding irrigated area are limited. We must therefore find ways to increase the productivity of water used for irrigation. This paper reviews the literature on irrigation efficiency and on the potential for increasing the productivity of water in rice-based systems. It stresses the continuing confusion over the concepts of irrigation efficiency and water productivity. It identifies the reasons for the wide gap between water requirement and actual water input (both irrigation diversions and rainfall) in irrigated rice production systems and discusses potential opportunities for increasing water productivity both on-farm and at the system level. Based on the reported low farm and system level irrigation efficiencies, the potentials for water savings in rice production appear to be very large. But we do not know the degree to which various farm and system interventions will lead to sustainable water savings in the water basin until we can quantify the downstream impact of the interventions. Studies on the economic benefits and costs, and environmental aspects of alternative interventions are also lacking. This paper emphasizes the need to measure the productivity of water at farm, system, and basin levels, and to understand how the productivity at one level relates to the productivity at another. Without water balance studies to measure productivity at these different scales, it is not possible to identify the potential economic benefits of alternative interventions and the most appropriate strategies for increasing irrigation water productivity in rice-based systems