International Nuclear Information System (INIS)

... Development Center, National Tsing-Hua University, Hsinchu, TW (China)

Energy Technology Data Exchange (ETDEWEB)

The NUclear Power Engineering Corporation (NUPEC) has developed IMPACT-SAMPSON code to analyze integral behavior of light water nuclear power plants under severe accident conditions. IMPACT-SAMPSON's distinguishing features include interconnected hierarchical modules and mechanistic models covering a wide spectrum of scenarios ranging from normal operation to severe accident events, and high-speed simulation on parallel processing computers. The integral plant behaviors of typical PWR and BWR under severe accident conditions have been analyzed with the IMPACT-SAMPSON code. The PWR plant analyzed was the three-loop, steel-dry containment type with 2,440 MWt. The AE accident scenario was supposed, that is, LOCA by 6-inch hot leg failure followed by accumulated water injection, but no ECCS and containment spray activation. The BWR plant analyzed was the 3,293 MWt BWR-5, ...

International Nuclear Information System (INIS)

Exposure control at the operating Nuclear Power Station is a major concern. TAPS Unit-4 is the first Pressurized Heavy Water Reactor of 540 MWe electrical capacity. This unit was made critical on March 6, 2005. In-depth review of radiation safety was done to identify the impact of design modification on dose rates at various locations and on the equipment's. Problems encountered in controlling the dose rates in 220 MWe electrical are eliminated by appropriate design modifications. Due to higher capacity of the unit there are design changes in major systems such as reactor core, primer heat transport system, moderator system, reactor regulation and protection systems. Reactor operations and maintenance activities during shut down contributes to exposure of the employees. Based on the experience gained in the operation of 220 MWe, design modifications incorporated ...

Energy Technology Data Exchange (ETDEWEB)

The integrity of the RPV head and reactor internals was assessed by means of fluid-structural analyses using a coupled method to evaluate the water hammer phenomenon arising from high burnup fuel failure under RIA conditions. The fluid viscosity effect on the water column burst as well as the complex three-dimensional flow paths caused by a core shroud and standpipes were considered in this study. The three analysis scenarios were designed to investigate the above mentioned influential factors separately. In the first scenario, a two-dimensional axisymmetric reactor vessel model without any reactor internals was modeled to assess the influence of the fluid dynamics in the NSC RIA regulatory evaluation. This model has an actual RPV geometry and can be simply separated from other influential factors in order to concentrate only on investigation of the fluid viscosity effect. In the ...

Energy Technology Data Exchange (ETDEWEB)

The Fixed Bed Nuclear Reactor (FBNR) is a small 40 MWe reactor based on the Pressurized Water Reactor (PWR) technology. FBNR is an integrated primary circuit and simple in design. It has the characteristics of being small, modular, proliferation resistant, inherently safe and passively cooled reactor with reduced adverse environmental impact. It utilizes the fuel designed for high temperature reactors operating in a relatively low temperature of PWR environment The 15 mm diameter spherical fuel elements are made of TRISO type microspheres embedded in graphite and cladded by SiC. The coolant flow transfers them from the fuel chamber into the core and become fixed forming a suspended core. Any accident signal will cut off the power to the coolant pump causing a stop in the flow. This results in making the fuel elements fall out of the ...

Energy Technology Data Exchange (ETDEWEB)

The objective of this research was to determine the extent of damage that occurs when two pipes experience an impact event due to one whipping against the other. The research was conducted through experimental and analytical approaches. The former required the development of a specialized impact machine that could accelerate a whipping pipe with sufficient energy to cause failure of a target pipe that was heated and pressurized to Pressurized Water Reactor (PWR) conditions. Damage was measured in terms of crushing, bending, and failure. The results of the tests permitted the correlation between pipes of a certain size and the damage they could cause when impacting with a certain amount of known energy. These results were used to evaluate the pipe whip criteria in the Standard Review Plan 3.6.2-4. It was established that the criteria conditions did not fully represent the results ...

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

In order to reduce the air concentration of (sup 3)H in the reactor buiIding of Wolsung Heavy Water Reactor, a computer code for estimation of adsorption behavior was programmed based on an equation derived for analysis of water vapor adsorption, and a ba...

International Nuclear Information System (INIS)

In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.

Science.gov (United States)

... small water or ice particles by impaction ... flight recording; principally the hydrometeor charge unit ... capability of directing aircraft movements by radio ...

International Nuclear Information System (INIS)

Object: To limit the discharge amount of reactor water in a primary system at the time of scram to prevent excessive outflow of reactor water outside the system. Structure: A signal from an upper limit position indicator detects the fact that control rods are completely inserted when the reactor is urgently stopped and the detection signal causes a valve in an outflow line of the discharge water from a control rod driving mechanism to be closed to limit the amount of discharge flown into the scram discharge vessel, thus preventing outflow of reactor water in the primary system after the scram has been initiated. (Kamimura, M.).

International Nuclear Information System (INIS)

The device of the present invention improves reactor safety by suppressing lowering of water level in a shroud which surrounds a reactor core, even upon occurrence of rupture of pipelines in an emergency reactor core cooling system in a recycling pump-incorporated type reactor. Namely, an opening of each of cooling systems which forms the emergency reactor core cooling device in a reactor pressure vessel is disposed above the upper end of the reactor core. Further, it also comprises an independent high pressure water injection system, gravitational dropping type water injection system and an automatic depressurization system. With such a constitution, even if rupture of pipelines in the system should be assumed, coolants never flow directly from the shroud which surrounds the ...

International Nuclear Information System (INIS)

THe high-temperature reactor is one of the alternatives for the now predominantly employed water-reactors. In a recently published book designer Rudolf Schulten outlines his concept. In this article the book is reviewed. (author). 1 ref.; 1 fig.

International Nuclear Information System (INIS)

Actinides other than the main uranium or plutonium isotopes take a growing part in the different stages of the nuclear cycle. For the French nuclear power program based on the development of light water reactors and fast breeders, many evaluations of the secondary actinides build up are made for the both reactor types using mainly the existing reactor codes. The comparison of these foreseen compositions with experimental results allows to perform some adjustments of the neutronic data. The secondary actinide compositions are given for some typical fuels and their consequences on the nuclear cycle are discussed. An hypothetical burning of these wastes in fast reactors has been studied and the main conclusions are reported.

International Nuclear Information System (INIS)

(1977). United States Parvez, A. Becker, M. Boguslawski, D. Harris,

Energy Technology Data Exchange (ETDEWEB)

The SCDAP/RELAP5 code has been developed for best estimate transient simulation of light water reactor coolant systems during a severe accident. The code models the coupled behavior of the reactor coolant system, core, fission product released during a severe accident transient as well as large and small break loss of coolant accidents, operational transients such as anticipated transient without SCRAM, loss of off-site power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits as much of a particular system to be modeled as necessary. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater conditioning systems. This volume describes the organization and manner of the interface between severe accident models which are resident in the SCDAP portion of the code and hydrodynamic models which are resident in ...

Energy Technology Data Exchange (ETDEWEB)

A submerged nuclear power station has been proposed as an alternative power station with a relatively low environmental impact for use by both industrialized and developing countries. The station would be placed 10 m above the seabed at a depth of 30--100 m and a distance of 10--30 km from shore. The submerged nuclear power station would be manufactured and refueled in a central facility, thus gaining the economies of factoryfabrication and the flexibility of short-lead-time deployment. To minimize the size of the submerged hull, horizontal steam generators are proposed for the primary-to-secondary heat transfer, instead of the more traditional vertical steam generators. The horizontal steam generators for SNPS would be similar in design to the horizontal steam generators used in the N-Reactors except the tube orientation is horizontal (the tube`s inlet and outlet connection points on the tubesheet are at the same elevation). Previous RELAP5 ...

International Nuclear Information System (INIS)

One of inherent characteristics of CANDU reactor is positive void reactivity in contrast to other pressurized light water reactors. During the large break loss of coolant accident, power pulse will be occurred during short time of early phase of accident due to positive void reactivity. However the duration of this power pulse is short, energy due to power pulse would be accumulated in the cladding material and will affect the peak cladding temperature or number of failed fuel elements. Recently, Canadian Nuclear Safety Commission (CNSC) indicated that the amount of void reactivity might be larger than the assumed values in safety analysis and this indication was based on the experimental data from ZED-2 facility. Based on that, the estimation of uncertainties due to the void reactivity during LBLOCA is the most important issue for CANDU safety analysis. In this study, a framework of uncertainty evaluation methodology for ...

International Nuclear Information System (INIS)

Debris coolability in the lower plenum of the reactor pressure vessel is an important factor for evaluation of debris in-vessel retention. The debris coolability analysis module is developed for the accurate prediction of the safety margin of the present reactor vessels in a severe accident. The module calculates debris spreading and cooling through melting and solidification in combination with a temperature distribution and failure evaluation of the vessel wall. Debris spreading is solved by the explicit method on a quasi-three-dimensional scheme and debris coolability is solved on the basis of natural convection analysis. The calculation for spreading is compared with a water spreading experiment on the floor and the calculation for coolability is compared with a n-octadecane melting experiment in a rectangular vessel. The comparisons show capabilities for predictions of spearhead transportation in the debris spreading ...

International Nuclear Information System (INIS)

Wolsung nuclear power plant has experienced four occasions of reactor shutdown owing to heavy water leaks since its commercial operation. Among these heavy water leaks, only one case was acute and brought about reactor shutdown but the other cases listed below were chronic and repaired after manual reactor shutdown. (author). 4 tabs., 10 figs.

Energy Technology Data Exchange (ETDEWEB)

The steam generator low water level trip setpoint of KORI NPP units 3 and 4(KNU 3 and 4), three-loop Westinghouse pressurized water reactor, is higher than that of OPR1000. In addition, steam generator downcomer water level in KNU 3 and 4 could fluctuate easily during a transient because of smaller downcomer water inventory, compared to the total water inventory in the steam generator. Due to these reasons, there is a higher possibility of unnecessary reactor trips caused by the steam generator low-low water level in KNU 3 and 4. Its operating history shows that most of reactor trips were caused by steam generator low-low level reactor trip signal. Such reactor trips, especially unnecessary ones, result in time and economic losses. In this paper, a ...

Science.gov (United States)

A report is presented of a hearing conducted before the Joint Committee on Atomic Energy on August 27, 1976, to discuss the legal implications for reactor licensing resulting from court challenges to procedures for assessing the environmental impact of radioactive waste disposal. (DG)

Energy Technology Data Exchange (ETDEWEB)

In this paper the possibility of configuring a water cooled Nuclear Thermal Propulsion (NTP) rocket, based on a Particle Bed Reactor (PBR) is investigated. This rocket will be used to operate on water obtained from near earth objects. The conclusions reached in this paper indicate that it is possible to configure a PBR based NTP rocket to operate on water and meet the mission requirements envisioned for it. No insurmountable technology issues have been identified.

Energy Technology Data Exchange (ETDEWEB)

The addition of ZnO, depleted in the Zn-64 isotope, to the water of boiling water nuclear reactors lessens the accumulation of Co-60 on the reactor interior surfaces, reduces radioactive wastes and increases the reactor service-life because of the inhibitory action of zinc on inter-granular stress corrosion cracking. To the same effect depleted zinc in the form of acetate dihydrate is used in pressurized water reactors. Gas centrifuge isotope separation method is applied for production of depleted zinc on the industrial scale. More than 20 years of depleted zinc application history demonstrates its benefits for reduction of NPP personnel radiation exposure and combating construction materials corrosion.

International Nuclear Information System (INIS)

This paper discusses the remote plugging of leaks in inaccessible pipework, with main reference to small leaks which frequently appear in ancillary cooling water circuits of nuclear reactors. Initially developed to cure problems of the pre-stressed concrete pressure vessels of UK reactors, the ZORIC sealant has been used to repair leaking biological shield pipework on six CANDU reactors. ZORIC is based on a water-soluble epoxy resin and an aqueous suspension of a refined mineral clay. This paper describes the evolution of the sealant, the qualification and testing program, and their application to CANDU reactor systems. 2 refs., 6 figs.

Energy Technology Data Exchange (ETDEWEB)

The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are unusually rapid.

International Nuclear Information System (INIS)

The heavy water reactor such as Wolsung No.1 and No.2 has a purification system to purify the reactor coolant. The control system regulates the coolant temperature to protect the ion exchanger. After the fuel exchanges of operating plant, the increase of the coolant pressure makes the purification temperature control difficult. In this paper, the controllability of the control dynamics of the purification system was analysed and the optimal parameters were proposed. To reduce the effects of the flow disturbance, the feedforward control structure was proposed and analysed.

International Nuclear Information System (INIS)

A survey was conducted of experience with steam generator tubes at nuclear power stations during 1976. Failures were reported at 25 out of 68 water-cooled reactors. The causes of these failures and the repair and inspection procedures designed to cope with them are summarized. Examination of the data indicates that corrosion was the major cause of steam generator tube failures. Improvements are needed in steam generator design, condenser integrity and secondary water chemistry control. (author).

UK PubMed Central (United Kingdom)

BackgroundStudies using transthoracic thermodilution have demonstrated increased extravascular lung water (EVLW) measurements attributed to progression of edema and...Full Text Available

Science.gov (United States)

(accumulates & stores brine for disposal). Separator. (separates water from purge gases). ? Purge pump periodically vent ... Reactor Health. Sensor. ( verifies reactor is operating w/n limits) ... Waste and Hygiene Compartment ...

International Nuclear Information System (INIS)

In the WWER-440 reactor the primary piping consists of six horizontal loops going radially from the pressure vessel, each loop having a horizontal steam generator. In this reactor type the relatively long primary piping with many curved sections requires special attention in order to successfully eliminate the consequences of the design basis accident. Emergency supports are located in appropriate places to restrict the movements of the pipe. Under normal conditions there is a gap of some centimeters between the pipe and a support so that in the pipe can be deformed freely under changing loads. This paper deals with those energy-absorbing structures used at the Loviisa Nuclear Power Plant for protection against impact loading. Places and circumstances where energy-absorbing structures are employed are specified. Development and design of impact absorber elements are discussed and ...

International Nuclear Information System (INIS)

Nuclear power in Romania was initiated on the basis of CANDU reactor type technology, an option found to fulfill the requirements for a sustainable economic development, to support the electric energy demand of the country and to ensure the population and environment protection. The construction of the Cernavoda NPP was heavily based on the Romanian industry participation and basic and applied nuclear research national resources. The experience acquired from Cernavoda NPP Unit 1 will be fructified in the construction of Units 2-5 to be built. The Romanian Ministry of Education and Research implemented a nuclear national program for research and development taking into account the European Union requirements and recommendations, the cooperation with the IAEA - Vienna and the Romanian government policy on short and medium terms in the nuclear field. The research-development program targeted: the reactor physics and nuclear fuel management; the ...

British Library Electronic Table of Contents (United Kingdom)

This study quantifies the external water footprint of the Netherlands by partner country and import product and assesses the impact of this footprint by contrasting the geographically-explicit water footprint with water scarcity in the different parts of the world. The total water footprint of the Netherlands is estimated to be about 2300 m^3/year/cap, of which 67% relates to the consumption of agricultural goods, 31% to the consumption of industrial goods, and 2% to domestic water use. The Dutch water footprint related to the consumption of agricultural goods, is composed as follows: 46% related to livestock products; 17% oil crops and oil from oil crops; 12% coffee, tea, cocoa and tobacco; 8% cereals and beer; 6% cotton products; 5% fruits; and 6% other agricultural products. About 11% o...

Energy Technology Data Exchange (ETDEWEB)

The objective of the Hanford Environmental Dose Reconstruction Project (HEDR) is to estimate the potential radiation doses received by people living within the sphere of influence of the Hanford Site. A potential critical pathway for human radiation exposure is through the consumption of waterfowl that frequent onsite waste-water ponds or through eating of fish, shellfish, and waterfowl that reside in/on the Columbia River and its tributaries downstream of the reactors. This document summarizes information on fish, shellfish, and waterfowl radiation contamination for samples collected by Hanford monitoring personnel and offsite agencies for the period 1945 to 1972. Specific information includes the types of organisms sampled, the kinds of tissues and organs analyzed, the sampling locations, and the radionuclides reported. Some tissue concentrations are also included. We anticipate that these yearly summaries will be helpful to individuals and ...

International Nuclear Information System (INIS)

The release rate of a nuclide from a reactor or a radioactive waste disposal plant at the accident is not steady, but varies with time. The various parameters of a nuclide migration into environment vary also day after day, or with the seasons. In such cases, dynamic behavior of the nuclide in the environment must be taken into consideration. It is difficult for a mathematical model to involve all of mechanisms for the nuclide migration. The environment for evaluation of doses are usually divided into some of compartments in which a nuclide concentration is uniform. Time variations of the nuclide concentration in the compartment are described in simultaneous differential equations. The nuclide concentration can be solved as a time function, and the radiation doses, therefore, can be estimated as a time function. Generic analysis code for dynamic compartment model (GACOM) is developed for the nuclide migration and the evaluation of doses in terrestrial biosphere. ...

British Library Electronic Table of Contents (United Kingdom)

In allusion to the explosion of a urea reactor took place in a fertilizer plant at Pingyin, Shandong, China, a series of evidence collection and inspection jobs which includes collecting operation condition and parameters, sampling the explosion fracture, reactor body apart from explosion fracture, and leak detection medium and its hangover, etc., had been carried out firstly. Based on these jobs, farther analysis and computation work has been done to the structural and materials characteristics and the operation condition of the urea reactor, including compositions, metallographic phases, tensile properties, impact energy, strain ageing characteristics, and fracture toughness of the urea reactor steels, the compositions of leak detection medium and its hangover in the urea reactor, and ex...

Science.gov (United States)

developing a consensus PRA standard for non- associated guidance light water reactor applications that will address some aspects of PRA in design. ...

Energy Technology Data Exchange (ETDEWEB)

This book contains the Proceedings of the Conference on Climate and Water under the following groupings: Impacts of climatic variability and change-resulting from the changes in hydrological variables; Aquatic environment; Terrestrial environment; Coastal zones and navigation; Urban and industrial water supply and drainage; Energy production; Intropogenic changes of climate and water management problems; Flood potential; Irrigation and land drainage.

International Nuclear Information System (INIS)

The circulating cooling water flowrate of GNPS and LNPS is totally about 190 m"3/s. Both stations are located on the western coast of semi-closed Daya Bay. A lot of studies concerning thermal impact of GNPS and LNPS have been carried out since 1987, including mathematical model, physical model, on-site survey and satellite remote sensing, etc. This paper describes the hydrological features of Daya Bay and discharge characteristics of circulating water of GNPS and LNPS, estimates the actual thermal impact of GNPS and LNPS, and indicates that it is advantageous for the dilution of circulating water while the two discharge channels of GNPS and LNPS are combined together towards east

International Nuclear Information System (INIS)

Dr. Rudolf Schulten of West Germany and expert witnesses from national laboratories, utilities, and the nuclear industry testified on reactor safety issues as they relate to the Chernobyl accident and public concern that modern technology has not paid enough attention to public safety. Each of the witnesses contributed safety-related information based on what has been learned from the Soviet incident. Particular focus went to similarities and differences between the Chernobyl and US reactors in safety design and engineering and to the environmental effects of the accident. The N reactor near Richland and a commercial reactor at Fort St. Vrain, Colorado are the only two operating graphite reactors, but neither is a boiling water reactor.

Energy Technology Data Exchange (ETDEWEB)

This is the sixth book on reactor materials published under sponsorship of the Naval Reactors Office of the United States Department of Energy, formerly the United States Atomic Energy Commission. This book presents a comprehensive compilation of the most significant properties of thorium dioxide, much like the book Uranium Dioxide: Properties and Nuclear Applications presented information on the fuel material used in the Shippingport Pressurized Water Reactor core.

International Nuclear Information System (INIS)

The concept of preliminary transmutation of minor actinides before placement to the long-term storage is considered. The purpose of such preliminary transmutation before ultimate storage is to incinerate a part of actinides and to transform another part into new actinides providing low level of radiotoxicity accumulated in the storage. Modes of transmutation in reactors of PWR, PHWR (CANDU), and Superfenix types are compared. Among power reactors, heavy-water PHWR type reactor is most acceptable for preliminary transmutation. (author)

International Nuclear Information System (INIS)

Manganese is a common contaminant of mine water and other waste waters. Due to its high solubility over a wide pH range, it is notoriously difficult to remove from contaminated waters. Previous systems that effectively remove Mn from mine waters have involved oxidising the soluble Mn(II) species at an elevated pH using substrates such as limestone and dolomites. However it is currently unclear what effect the substrate type has upon abiotic Mn removal compared to biotic removal by in situ micro-organisms (biofilms). In order to investigate the relationship between substrate type, Mn precipitation and the biofilm community, net-alkaline Mn-contaminated mine water was treated in reactors containing one of the pure materials: dolomite, limestone, magnesite and quartzite. Mine water chemistry and Mn removal rates were monitored over a 3-month ...

Energy Technology Data Exchange (ETDEWEB)

This report discusses a desk-top computer program has been developed for estimating the costs, waste volumes, and occupational radiation exposures associated with decommissioning light-water reactor power stations. Cost categories and cost algorithms used in the program are discussed and a brief description of the user interface is given.

International Nuclear Information System (INIS)

Purpose: To eliminate the water level deviation due to the recycling flowrate, as well as enable a stable control to a reference value even upon changes in the recycling flowrate caused by the variation in the opening degree of a minimum flow valve. Constitution: Reactor recycling system comprises a feedwater pump, a flowrate control valve, a reactor water level detector, and a minimum flow line and a minimum flow valve for preventing the overheating of the feedwater pump at a low flowrate. A flowrate compensator is further disposed, in which a recycling flowrate signal is subtracted from a pump flow rate signal and the result is fedback as a compensated pump flowrate signal. This enables the control system to operate at a rapid response for suppressing the effect of the recycling flowrate as external disturbance, whereby the water level in the reactor can be ...

Science.gov (United States)

This report presents a general investigation of the transport requirements associated with the construction and operation of conceptual fusion reactors. Projections of amounts of construction and operating materials requiring transportation are presented for several proposed designs. The material to be shipped is described along with the shipping containers that might be used, the transport modes and the expected impact of transporting these materials. Transportation of both radioactive and nonradioactive materials will be required. Most of these materials are routinely shipped by the transportation industry. Transportation requirements of a representative fusion reactor are also compared with Liquid Metal Fast Breeder Reactor (LMFBR) requirements.

International Nuclear Information System (INIS)

Active Process Water (APW) System, provided as unitized closed loop system in Tarapur Atomic Power Project Units-3 and 4, serves to remove heat from various heat exchangers. One of the important loads served by APW system is shutdown cooling heat exchangers and if APW shutdown is taken then reactor cannot be maintained in cold shutdown condition. It is estimated that after 7 days of reactor shutdown, if about 20% of the normal cooling flow to shutdown cooling heat exchangers is provided then along with keeping PHT in cold shutdown state, reactor components, moderator, end shield water, calandria vault water and calandria vault concrete temperature can be maintained within technical specification limits for extended duration. (author)

Energy Technology Data Exchange (ETDEWEB)

Ammonia is a common and highly toxic pollutant which, in sufficient quantities, will adversely affect aquatic organisms. This ammonia criteria document for salt water will allow establishment of regulatory standards for ammonia discharge into estuaries, near coastal zones and oceans. Possible adverse impacts in highly sensitive and abundant ecosystems such as estuaries make regulation particularly important.

Energy Technology Data Exchange (ETDEWEB)

Comments are made on the Public Inquiry into CEGB's proposal to construct a pressurized water reactor (PWR) at Sizewell, UK. Aspects discussed include: time elapsed and its possible effect on the result; economics of nuclear power plants compared with coal-fired power plants; changes in real sterling/dollar exchange rates; effect of mineworkers' strike; the UK electric power generating system; AGR reactors compared with PWR reactors; extension of Magnox reactor life; radioactive waste management; political decisions.

Energy Technology Data Exchange (ETDEWEB)

The calculated radioactive waste inventories of the Turkey Point pressurized water fission reactor (PWR) and the Starfire conceptual fusion tokamak are compared as a function of time from initial start-up to 10,000 years after decommissioning. Only material out of reactor at least one year is considered. The total activity in Ci/W(th) of the Starfire tokamak is slightly greater than that of the PWR during the active lifetimes of the two reactors and beyond 1000 years. However, using reduced activation materials in Starfire can result in about 1/2000 as much long-lived radioactivity as in the fission reactor. It is stressed that comparison of wastes on this basis is not straightforward, since the radioisotopes and methods required for their disposal are different for fusion and fission reactors. 2 refs., 1 fig., 2 tabs.

International Nuclear Information System (INIS)

In light of the recent rapid increase in the fossil fuel prices it is meaningful to evaluate the impact of these price changes in the economics of dual-purpose desalination projects producing electricity and fresh water simultaneously. The price of crude oil and LNG (Liquefied Natural Gas) has increased by about 200% and 100% during the past three or four years. The uranium price has also increased by nearly 500% during the same period. The purpose of this paper is to analyze and compare the economics of SMART (System-integrated Modular Advanced ReacTor) which is being developed as a small size PWR type and the LNG Combine Cycle coupled with MED (Multi-Effect Distillation) which are being acknowledged as promising energy sources for the future in Korea. The methods of analysis used in this paper are the lifetime leveled cost method for the power and water cost calculation and the power credit method for ...

International Nuclear Information System (INIS)

In an existent emergency reactor core cooling device, if a ruptures should occure in a pipeline of a gravitational dropping type reactor core cooling system pool (GDCS) due to some or other causes, a portion of GDCS pool water was flown out of the ruptured port and could not be used for reactor core cooling. Then, a difference pressure detector is disposed to a GDCS pipeline at the inlet of a reactor pressure vessel. When it is judged by the detector, that coolants flow to the outside of the injection pipeline, an injection value disposed to the GDCS pipeline is closed by the difference pressure signal. Even if a rupture should occur on the side of the pressure vessel at downstream to the check value of the GDCS pipeline, since backflow is caused at the pressure container inlet of the GDCS pipeline with the rupture port, the rupture is detected by the difference pressure detector to ...

Energy Technology Data Exchange (ETDEWEB)

Before the implementation Water Framework directive, it was usual to forget that a good environment protection of the receiving waters needs a correct and coordinated operation of the subsystems of the water cycle, specially sewerage system, WWTP and receiving waters. This explains that most of the countries have focused their efforts in the treatment of dry weather flows forgetting the management of wet weather flows. Actually the idea that a sewerage system or a WWTP can not be planned or managed independently without considering the effects on the receiving waters is commonly accepted because not only each one of these systems must work correctly but also it is required a minimum impact in the receiving waters of the sewerage and WWTP overflows in dry and wet weather. All these links will affect the management strategy of the sewerage ...

British Library Electronic Table of Contents (United Kingdom)

We present an innovative approach to estimating residential irrigation water demand for a large metropolitan area using GIS data, weather station data, and a water budget modeling approach commonly used by plant scientists and landscape management professionals. An important question addressed by our study is how a growing urban forest affects the overall irrigation water demand of a semiarid metropolitan area. To estimate the amount of water required by residential landscaping, we consider water demand to be a function of the areal extent of residential landscaping (i.e. tree/shrub or turf grass), the water-loss rate for different landscaping types, the efficiency with which the landscape is irrigated, and local climatic factors (i.e. reference evapotranspiration and precipitation). We es...

International Nuclear Information System (INIS)

The present paper deals with the experimental determination of pressure drop across a four-cusped vertical channel. This geometry represents, ideally, the blockage condition in a typical pressurized water reactor with core degraded by accident. Experiments were performed for both single and two-phase flow. Water was utilized for the single-phase measurements whilst simultaneous flow of air and water simulated the steam-water flow. Observation of the prevailing two-phase flow regime was carried out, so that its mechanism could be fully understood. The averaged void fraction was also measured, by the gamma-ray attenuation technique. A wide range of water and air mass flow rates was covered, so that all flow conditions, possible to exist in a reactor with LOCA, could be investigated. New correlations for pressure drop are proposed. (Author).

Science.gov (United States)

Results of feasibility experiments for determining the mineral content of individual stains on special Sensitized Paper are presented. The stains were formed on the paper by the impaction of laboratory generated salt water droplets. Of the techniques exam...

Energy Technology Data Exchange (ETDEWEB)

The purpose of the study is to analyze the economic impact which could result from the application of effluent limitations guidelines and standards issued under Sections 301, 304, 306, 307, 308, and 501 of the Clean Water Act to the plastics molding and forming industry.

Environmental Research Database

DescriptionFarm-level estimates of the financial impact of regulation are important indicators of the effect that a regulation have. Such estimates should be included in RIA, particularly within the Small Firms Impact Test. This farm-level analysis can be used in the RIA to inform judgements of the affordability of the regulation proposal. It will help to identify which farm types are likely to be financially had-hit from the regulation. Farm-level cost estimates for each regulation are also required t [continued...

International Nuclear Information System (INIS)

Tarapur Atomic Power Station unit-4 is first 540 MWe pressurized heavy water reactor. Heavy water is used as the coolant and moderator. With reactor operation tritium is formed by absorption of neutron by deuterium atoms. Experience in the 220 MWe indicates that tritium is main contributor to the internal dose of radiation workers. Study on tritium build up in Primary Heat Transport (PHT) and Moderator (MOD) system was carried out at the initial stage of the operation of the unit-4. This paper brings out tritium activity buildup in the PHT and MOD systems and its comparison with 220 MWe reactors. This paper helps in estimation of the internal dose contribution to the radiation workers at TAPS 3 and 4. (author)

Energy Technology Data Exchange (ETDEWEB)

The Advanced Neutron Source will be a new world-class facility for research using hot, thermal, cold, and ultra-cold neutrons. The heart of the facility will be a 330-MW (fission), heavy-water cooled and heavy-water moderated reactor. The reactor will be housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides will fan out into a large guide hall, housing about 30 neutron research stations. Appropriate office, laboratory, and shop facilities will be included to provide a complete facility for users. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory early in the next decade. This PDR document defines the plant-level requirements for the design, construction, and operation of ANS. It also defines and provides input to the individual System Design ...

CERN Document Server

We study the impact of very light sterile neutrinos (Delta m^2_new around 1 to 10 times 10^(-2) eV^2, sin^2 2theta_new<10^(-1)) on upcoming theta_13-driven reactor antineutrino experiments like Double-CHOOZ and Daya Bay. Oscillations driven by these vales of Delta m^2_new affect data in the near and far detectors differently and hence potentially modify the capability of these experimental setups to constrain and measure sin^2 2theta_13. We find that the hypothesis theta_new different from zero negatively impacts one's ability to either place an upper bound on sin^2 2theta_13 in the advent of no oscillation signal or measure sin^2 2theta_13 if a theta_13-driven signal is observed. The impact of sterile neutrino effects, however, depends significantly on one's ability to measure the recoil positron energy spectrum. If sin^2 2theta_new is larger than 10^(-2), upcoming theta_13-driven ...

International Nuclear Information System (INIS)

Purpose: To remove excessive driving pressure applied to an unisolated control rod drive by returning excessive coolant to a condensed water storage tank or to the inlet side of a drive water pump using a coolant flow rate control pipe of a control rod driving hydraulic system. Constitution: Excessive water is returned to a condensed water tank while controlling the excessive coolant by a flow control valve in response to variations in the pressure difference between the reactor pressure and the driving water line when the control rods are isolated using a pipe from the outlet side of the drive water pump to the condensed water storage tank. Thus, the control rod to be isolated is prevented form being dropped. (Sekiya, K.).

CERN Document Server

The finite element method and dimensional analysis have been applied in the present paper to study a hydraulic impact, which is utilized in a non-explosive rock breaking technology in mining industry. The impact process of a high speed piston on liquid water, previously introduced in a borehole drilled in rock, is numerically simulated. The research is focused on the influences of all the parameters involved in the technology on the largest principal stress in the rock, which is considered as one of the key factors to break the rock. Our detailed parametric investigation reveals that the variation of the isotropic rock material properties, especially its density, has no significant influence on the largest principal stress. The influences of the depth of the hole and the depth of the water column are also very small. On the other hand, increasing the initial kinetic energy of the piston can dramatically ...

Energy Technology Data Exchange (ETDEWEB)

A contamination event in a water distribution system can result in adverse health impacts to individuals consuming contaminated water from the system. Assessing impacts to such consumers requires accounting for the timing of exposures of individuals to tap-water contaminants that have time-varying concentrations. Here we present a probabilistic model for the timing of ingestion of tap water that we developed for use in the U.S. Environmental Protection Agency's Threat Ensemble Vulnerability Assessment and Sensor Placement Tool, which is designed to perform consequence assessments for contamination events in water distribution systems. We also present a statistical analysis of the timing of ingestion activity using data collected by the American Time Use Survey. The results of the analysis provide the basis for our model, which ...

International Nuclear Information System (INIS)

The potential public safety impacts from accidents in conceptual fusion power plants were investigated. Fusion was found to have some potential for accidents, as does any energy generating system. Functions of fusion power plants were identified that possess sufficient potential for an accidental release of toxic materials to the environment. An assessment was made of the impact of the potential accidents and recommendations are included for R and D that will allow incorporation of safety concerns in fusion power plant design. This work was based on a review of information available in conceptual design documents of fusion reactor systems.

International Nuclear Information System (INIS)

This report summarizes work performed by Argonne National Laboratory (ANL) on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) during the six months from October 1993 to March 1994. EAC and fatigue of piping, pressure vessels, and core components in LWRs are important concerns in operating plants and as extended reactor lifetimes are envisaged. Topics that have been investigated include (a) fatigue of low-alloy steel used in piping, steam generators, and reactor pressure vessels, (b) EAC of wrought and cast austenitic stainless steels (SSs), and (c) radiation-induced segregation and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS after accumulation of relatively high fluence. Fatigue tests have been conducted on A302-Gr B low-alloy steel to verify whether the current predictions of modest decreases of fatigue life in simulated pressurized ...

British Library Electronic Table of Contents (United Kingdom)

One proposed solution to the problem of ballast-mediated aquatic invasions involves chemically treating ballast water to kill key target organisms. Here, we examine the efficacy of three commercially available ballast water biocides using vegetative microalgae, dinoflagellate resting cysts and bacteria as test organisms. Chemicals tested were the ballast water biocides SeaKleen and Peraclean Ocean, and the chlorine dioxide biocide Vibrex. Results demonstrate that the applicability of each of the three chemical biocides as a routine ballast water treatment is limited by factors such as cost, biological effectiveness and possible residual toxicity of the discharged ballast water (assessed on the basis of impact on motility of vegetative marine microalgae). Of the three biocides tested, Perac...

Energy Technology Data Exchange (ETDEWEB)

To meet BPA`s contractual obligation to supply electrical power to its customers, BPA proposes to acquire power generated by Klickitat Cogeneration Project. BPA has prepared an environmental assessment evaluating the proposed project. Based on the EA analysis, BPA`s proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 for the following reasons: (1)it will not have a significant impact land use, upland vegetation, wetlands, water quality, geology, soils, public health and safety, visual quality, historical and cultural resources, recreation and socioeconomics, and (2) impacts to fisheries, wildlife resources, air quality, and noise will be temporary, minor, or sufficiently offset by mitigation. Therefore, the preparation of an environmental impact statement is not required and BPA is ...

International Nuclear Information System (INIS)

Eight years ago, corrosion and tube denting seriously threatened the reliability and design life of steam generators, especially for closed loop arrangements in pressurized water reactors (PWRs). Concentrated research by the Steam Generator Owners Group (SGOG) diagnosed the causes and produced effective solutions, notably guidelines for water chemistry control in the secondary loop. The guidelines recommend specific levels of water impurities and remedial actions to prevent cooling-water leaks in the condenser, prevent air leaks, limit corrosion product buildup, and remove some impurities while neutralizing others. Continued research in SGOB-II is investigating intergranular corrosion and stress corrosion cracking. 3 figures.

Science.gov (United States)

In this paper, a novel type of a corona discharge plasma reactor was designed, which consists of needle-plate-combined electrodes, in which a series of needle electrodes are placed in a glass container filled with flue gas, and a plate electrode is immersed in the water. Based on this model, the removal of NO and SO2 was tested experimentally. In addition, the effect of streamer polarity on the reduction of SO2 and NO was investigated in detail. The experimental results show that the corona wind formed between the high-voltage needle electrode and the water by corona discharge enhances the cleaning efficiency of the flue gas because of the presence of water, and the cleaning efficiency will increase with the increase of applied dc voltage within a definite range. The removal efficiency of SO2 up to 98%, and about 85% of NOx removal under suitable conditions is obtained in our experiments.

Energy Technology Data Exchange (ETDEWEB)

This report has reviewed the construction of a cooling tower for the K reactor at the DOE Savannah River Site in Aiken, South Carolina. It has been found that the cooling tower would prevent further destruction of cypress and tupelo trees, would maintain a more consistent flow from site streams, and would allow earlier recovery of stream corridors inside a portion of the site. About 630 acres of wetlands have already been affected by the hot water discharged by the K reactor during the past 35 years. GAO believes that about 10 to 12 acres of additional damage would be prevented by the tower for every year the reactor is operated, and if current plans for re-start and retirement of the reactor are followed, less than 100 acres would be preserved. As requested, GAO also identified an example of a project that could be funded as compensation to the public for the damage the K ...

Science.gov (United States)

A novel reactor combining a flame-deposited nanostructured titanium dioxide film and a set of embedded ceramic electrodes was designed, developed and tested for degradation of methyl tert-butyl ether (MTBE) in water. On applying a voltage to the ceramic electrodes, a surface coro...

Energy Technology Data Exchange (ETDEWEB)

Late last year the Wolsung Candu in Korea suffered an incident which resulted in heavy water being released from the primary system into the containment. With the unit now back at full power, this article examines the causes of the incident and the action which is being taken to prevent it happening again.

Science.gov (United States)

While tritium exposure to the site-workers in Wolsung NPP is up to about 40% of the total personnel exposure, Ministry of Science and Technology has asked tritium removal facility for requirement of post heavy-water reactor construction. For the purpose o...

International Nuclear Information System (INIS)

The development and successful application of a unique leak sealant formulation comprised of a mixture of graded, hollow ceramic microspheres, surface oxidized aluminum powder and saturated gibbsite suspension is described. The project was undertaken to address the escalating leakage from up to 15 small weld defects in the water reflector vessel, an integral component of the NRU (National Research Universal) reactor calandria. The reflector surrounds the reactor core with a neutron reflecting blanket of light water. Injection of the sealant is typically done with the reactor shutdown and the water reflector system operating normally, but can also be performed with the reactor at full power. The procedure is simple and effective. Individual treatments of as little as 125 ml of sealant (10 ppm in the 12,500 L system) have yielded leak ...

Science.gov (United States)

The Wolsung-type nuclear fuel localization project carried out since 1981 finally reached to a full-fledged phase in 1987. We successfully produced and timely delivered a yearly demand of nuclear fuel for Wolsung unit 1. In this report we studied and summ...

Energy Technology Data Exchange (ETDEWEB)

Coal bed natural gas (CBNG) development in the Powder River (PR) Basin produces modestly saline, highly sodic wastewater. This study assessed impacts of wetting four textural groups (0-11%, 12-22%, 23 -33%, and > 33% clay (g clay/100 g soil) x 100%))with simulated PR or CBNG water on water retention. Soils received the following treatments with each water quality: a single wetting event, five wetting and drying events, or five wetting and drying events followed by leaching with salt-free water. Treated samples were then resaturated with the final treatment water and equilibrated to -10, -33, -100, -500, or -1,500 kPa. At all potentials, soil water retention increased significantly with increasing clay content. Drought-prone soils lost water-holding capacity between saturation and field capacity with repeated ...

Energy Technology Data Exchange (ETDEWEB)

Chlorination of water can lead to the formation of chloropicrin. The numerous potential precursors (of various reactivities) observed during this study, confirm this hypothesis. Combination of ozonation and chlorination can also lead to the formation of this compound, dangerous to health; however, the conditions of the formation and particularly the impact of a nitration reaction in the gas phase are still not clearly defined.

International Nuclear Information System (INIS)

A review of the performance of steam generator tubes in 116 water-cooled nuclear power reactors showed that tubes were plugged at 54 (46 percent) of the reactors. The number of tubes removed from service decreased from 4 692 (0.30 percent) in 1981 to 3 222 (0.20 percent) in 1982. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that have used only volatile treatment, with or without condensate demineralization.

International Nuclear Information System (INIS)

Existing applications of Alloy 800 are summarized, with particular reference to its use in various types of reactor. The need for a co-ordinated research and development programme is stressed, and the variables to be explored are outlined. The papers relating to the problem of corrosion and cracking in water and steam are considered. the strength and ductility of Alloy 800 is considered. Finally, sections of the summary deal with the use of Alloy 800 for (a) sodium cooled fast reactor boiler tubes; (b) the high temperature gas cooled reactor; and (c) PWR steam generator tubes. (U.K.).

International Nuclear Information System (INIS)

The activation aspects of pure fusion and hybrid fusion technology is studied to assess the radioactive safety of various fusion concepts including tokamak pure fusion, fissile fuel producing hybrid and radio waste transmuting hybrid. The activation properties of breeding, coolant and structural materials in fusion reactors might be quite different from those in fission reactors because of the high energy D-T fusion neutrons from the fusion cores. A study on the involved activation reactions and the uncertainties of the associated nuclear cross-sections is carried. The activation properties of various first wall concepts and blanket concepts are discussed. The radioactive inventory during the operation lifetime and the potential hazard of the radioactive nuclides with respect to near term (reprocessing) and long term (waste disposal) aspects are calculated, with reference to ITER/NET (International Thermonuclear Experiment ...

International Nuclear Information System (INIS)

Problem areas in BWRs, PWRs and PHWRs, from the viewpoint of chemistry, and the problem of fission product release in nuclear reactors are discussed. These problem areas are : fuel performance, off-normal water chemistry due to condenser leaks, the transport and deposition of the activated corrosion and fission products, denting in steam generators (in the case of PWRs), ingress of air in the cover gas helium and consequent radiolysis of D_2O in the moderator circuit (in the case of PHWRs). (M.G.B.).

International Nuclear Information System (INIS)

On the 3. and 4. November 1982 the sixth conference of the Corporation for Reactor Safety (GRS) was held in Cologne's Guerzenich. The theme of this year's meeting was the 'Status of Risk Investigations at Nuclear Power Plants'. A principal topic was a report on findings made by the GRS during the 'Risk Oriented Analysis SNR-300'. The second topic comprised the newest developments within Phase B of the Risk Study of Water Pressure Reactors, the discussion of the dose/effect relationship and considerations on threshold risk values. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Waste management, like many other issues, has experienced major milestones. In 1971, the Calvert Cliff's decision resulted in an entirely different approach to the consideration of environmental impact analysis in reactor siting. The accidents at Three Mile Island and Chernobyl have had profound effects on nuclear power plant design. The high-level waste repository program has had many similar experiences that have modified the course of events. The management of radioactive, hazardous chemical and mixed waste in all of the facilities of the Oak Ridge Operations (ORO) Office of the Department of Energy (DOE) took on an entirely different meaning in 1984. On April 13, 1984, Federal Judge Robert Taylor said that DOE should proceed 'with all deliberate speed' to bring the Y-12 plant into compliance with the Resource Conservation and Recovery Act and the Clean Water Act. This decision resulted from a ...

International Nuclear Information System (INIS)

The neutron data required to completely analyze fission reactors includes many isotopes and covers a broad energy range. In both fast and thermal reactors, the neutron inventory is a fine balance determined by the fission properties of "2"3"5U, "2"3"9Pu and "2"3"8U and by the capture cross sections of "2"3"8U, fuel materials, structural materials and coolant materials. In fast reactors, the spectrum of neutrons ranges from 1 keV to 3 MeV and is influenced by the elastic and inelastic scattering properties of "2"3"8U and the structural and coolant materials. For neutron shielding applications, the important neutron data include the total cross sections of structural and coolant materials in the MeV range. The impact of these basic nuclear data in fission reactor applications is most suitably described by sensitivity analysis. For example, sensitivity coefficients computed for a ...

International Nuclear Information System (INIS)

Purpose: In a case of automatically controlling the water level at the time of generating a lower power, to impact the followability of the control necessary for the power variation of the steam generator thereby to obtain good controllability. Constitution: A signal of deviation of water level of a steam generator and its set value and a signal of a difference between the temperature of the primary coolant in the high temperature side pipeline and that of the primary coolant in the low temperature side pipeline are used to automatically or manually control the flow quantity of water fed to the steam generator. (Yoshihara, H.).

International Nuclear Information System (INIS)

Full text: The nuclear renaissance, anticipated by AREVA in the beginning of the century is now happening in several countries around the world. The fundamentals being the increasing demand of energy, the volatility of fossil fuel prices, the awareness of climate change threat connected with the extensive use of fossil fuels. The EPRTM reactor present significant improvements compared to previous generation reactors enabling to reach an outstanding safety level (redundancy of safety systems, airplane crash resistance), to improve the economics (extended plant lifetime, flexibility and availability during operation and, increased efficiency and fuel utilization) while limiting the impact on workers and the environment. Several countries have been implementing the transition to third generation reactors. The presentation will analyze different examples in order to draw the lessons learned from this first ...

International Nuclear Information System (INIS)

This paper explores the potential implications of climate change for the use and management of water resources in Britain. It is based on a review of simulations of changes in river flows, groundwater recharge and river water quality. These simulations imply, under feasible climate change scenarios, that annual, winter and summer runoff will decrease in southern Britain, groundwater recharge will be reduced and that water quality - as characterised by nitrate concentrations and dissolved oxygen contents - will deteriorate. In northern Britain, river flows are likely to increase throughout the year, particularly in winter. Climate change may lead to increased demands for water, over and above that increase which is forecast for non-climatic reasons, primarily due to increased use for garden watering. These increased pressures on the water resource base will ...

British Library Electronic Table of Contents (United Kingdom)

Human activities in the karst Ozark Plateaus can impact water quality of springs where surface water is rapidly transferred to subsurface conduits. Bennett Spring, in southern Missouri, is the fourth largest spring in the state and supports local tourism activities. Questions regarding poorly functioning on-site wastewater systems (OWS) have raised concerns over the long-term water quality of the spring. This study reports the results of a surface water quality monitoring program in the recharge area where monthly samples were collected at base flow to identify potential pollution sources to the spring. Base flow hydrology of the recharge area was highly variable over the study period, which was drier than normal, causing an incomplete sampling record due to no flow conditions at some site...

Energy Technology Data Exchange (ETDEWEB)

The influence of radiation on the corrosion of the fuel claddings in a Light Water Reactor (LWR) has been the subject of many investigations, and different aspects of the overall phenomena have been studied by different techniques. Analysis of the evolution of Secondary-Phase Particles (SPPs) for different periods of immersion of the cladding in the reactor enables the rate of corrosion to the structure of the material to be correlated. In the case of Zircaloy-2 in a Boiling Water Reactor (BWR), SPPs are dissolved under irradiation, and their dissolution affects the rate of oxidation and other correlated phenomena. In recent studies, the Zircaloy-2 in claddings loaded in the Leibstadt BWR are analysed after one, three and five cycles. Results are presented, and give an account of the changes which occurred in the materials under irradiation. (authors)

International Nuclear Information System (INIS)

Heat transfer augmentation based on the process intensification concept in heat exchangers and thermal reactors has received much attention in recent years, mainly due to energy efficiency and environmental considerations. The concept consists of the development of novel apparatuses and techniques that, compared to those commonly used today, are expected to bring dramatic improvements in manufacturing and processing, substantially decreasing equipment size, energy consumption, and ultimately resulting in cheaper, sustainable technologies. The objective of this paper was to investigate the heat transfer characteristics of tubular thermal reactor using static mixing technology. Glycerin and water were used as the test fluids and water was used as the heating source. The results for heat transfer rate were strongly influenced by tube geometry and flow conditions.

International Nuclear Information System (INIS)

GRR-1 is a 5MW open pool type research reactor with MTR-type fuel elements cooled and moderated by light water with beryllium reflectors at the two opposing sides of the core. A graphite thermal neutron column is adjusted to one side of the core. Six radial horizontal beam tubes are available, of which three contain in-pile collimators for neutron scattering instruments. The reactor is currently out of operation for inspection and refurbishment purposes. The core has been dismantled and the fuel elements are stored in the used fuel storage tank. The GRR-1 inspection and refurbishment plan involves inspection and eventually replacement of the reactor's primary cooling circuit. The health physics procedures to be implemented during inspection of the main water outlet are divided in three stages: a) pool dose rate survey from pool top, b) pool drainage by decreasing ...

International Nuclear Information System (INIS)

MOX fuel has been one of the mature nuclear fuels which can be used in light water nuclear power plant now. The development status in this domain in foreign countries, the major influence of MOX fuel on reactor performance and the countermeasures are introduced in this paper. The application of MOX fuel in China's PWR is discussed in the end. (authors)

Energy Technology Data Exchange (ETDEWEB)

This standard addresses the design bases for light water reactor, nuclear power plant structures and components essential for the protection of public health and safety from the potential adverse effects of pipe whip, jet impingement, pressurization of compartments outside containment, environmental conditions and flooding associated with a postulated pipe rupture. The design bases for missile protection and the design bases for containment pressurization are not within this standard.

Energy Technology Data Exchange (ETDEWEB)

The US Nuclear Regulatory Commission is proposing to amend the regulations that currently require that the design basis for nuclear power plants include the postulation of dynamic effects from loss of coolant accidents up to and including the double-ended rupture of the largest pipe in the reactor coolant system. Proposed modifications would allow analyses to serve as a sufficient basis for excluding dynamic effects, including but not necessarily limited to pipe whip and jet impingement, associated with specific pipe ruptures. Only dynamic effects would be impacted; current design requirements for containment sizing and discharge capacity of emergency core cooling systems would remain unchanged. This report presents a detailed analysis of value-impact associated with the proposed amendment for PWR reactor coolant loop piping and for BWR recirculation loop piping. The effect of extending application of ...

Energy Technology Data Exchange (ETDEWEB)

Previous experiments in fast critical assemblies demonstrated a method of determining reactivity from power spectral density measurements with /sup 252/Cf. This method determines reactivity from properties of the reactor only at the subcritical state of interest, thus it does not require a calibration near delayed criticality. The interpretation of the measured data to obtain reactivity does not require knowledge of the relative or absolute values of the source intensity, knowledge of the detection efficiencies, or knowledge of the detection instrumentation frequency responses. An experiment was performed at the Pool Critical Assembly to evaluate the possibility of /sup 252/Cf source driven neutron noise spectral density measurements in light water moderated reactors. This experiment showed that using commercially available detectors, such measurements can be performed in a reasonable time, that is, the measurement of the ...

International Nuclear Information System (INIS)

In the radiochemical reprocessing of spent fuel from nuclear reactors, a considerable amount of liquid, solid, and gaseous waste is formed; this waste is potentially dangerous to humans and requires the development of special and complex technological techniques for its localization and reliable long-term storage. The most hazardous are liquid wastes of high specific activity - water-tailings solutions obtained in the first cycle of extraction after the removal of uranium and plutonium. These solutions contain more than 99.9% of all the other transuranic elements - isotopes of neptunium, americium, and curium. Where necessary, some fission products and actinides may be removed from wastes of high specific activity for subsequent use. The quantity, composition, and activity of these wastes varies within broad limits, depending on the type and power of the reactor, the initial nuclide composition of the fuel, and its specific ...

Energy Technology Data Exchange (ETDEWEB)

Work at Institutt for energiteknikk (IFE) comprises both nuclear and non-nuclear activities. The main nuclear program is centered on the Halden Reactor Project. In 1958, the first Halden Reactor Project Agreement was signed by organisations representing 12 European countries. During 1994 France became a full member and associate membership was established with Russia. Accordingly, 16 countries were participating in the Project by the end of the year. The objectives have evolved from being simply a demonstration of the operation of a boiling heavy-water reactor to becoming a substantial research and development programme covering the domains of human-machine interaction, fuel behaviour, materials testing, water chemistry, and instrumentation. In 1994, significant progress was achieved in all of the areas addressed by the project, including the re-instrumentation of irradiated fuel ...

International Nuclear Information System (INIS)

Heat transfer tubes of a primary pressurized water cooled (PPWC) in the high temperature engineering test reactor (HTTR) form the reactor pressure boundary of the primary coolant, therefore are important from the viewpoint of safety. To establish inspection techniques for the heat transfer tubes of the PPWC, an automatic inspection system was developed. The system employs a bobbin coil probe, a rotating probe for eddy current testing (ECT) and a rotating probe for ultrasonic testing (UT). Nondestructive test of a half of the heat transfer tubes of the PPWC was carried out by the automatic inspection system during reactor shutdown period of the HTTR (about 55% in the maximum reactor power in this paper). The nondestructive test results showed that the maximum signal-to-noise ratio was 1.8 in ECT. Pattern and phase of Lissajous wave, which were obtained for the heat transfer tube of ...

Energy Technology Data Exchange (ETDEWEB)

The Materials and Components Technology Division (MCT) provides a research and development capability for the design, fabrication, and testing of high-reliability materials, components, and instrumentation. Current divisional programs related to nuclear energy support the development of the Integral Fast Reactor (IFR): life extension and accident analyses for light water reactors (LWRs); fuels development for research and test reactors; fusion reactor first-wall and blanket technology; and safe shipment of hazardous materials. MCT Conservation and Renewables programs include major efforts in high-temperature superconductivity, tribology, nondestructive evaluation (NDE), and thermal sciences. Fossil Energy Programs in MCT include materials development, NDE technology, and Instrumentation design. The division also has a complementary instrumentation effort in support of Arms Control ...

Energy Technology Data Exchange (ETDEWEB)

The design of the first structural wall (FSW) in an inertial confinement fusion (ICF) reactor requires some knowledge of the expected wall loading produced by x-ray and neutron deposition; specifically in the High Yield Lithium Injection Fusion Energy (HYLIFE) reactor, wall loading results from two sources -- gas shock and liquid impact. Gas shock is derived from x-ray deposition in the thin layers of exposed blanket material, producing ionized vapor, which will generate gas shock on the FSW. Liquid impact, on the other hand, results from the acceleration of liquid blanket material by two possible forces -- the drag from vapor expansion through the blanket material and the neutron-induced isochoric disassembly process. Both impacts, however, are coupled by the interaction of hot gas expanding through the liquid blanket. This paper discusses scaling methods for estimating pressure ...

British Library Electronic Table of Contents (United Kingdom)

Spherical nano-sized YSZ (yttria stabilized ZrO2) powders were successfully synthesized via a reverse microemulsion system. The water droplets in the microemulsion system of yclohexane/water/span85/Triton X-100/hexyl alcohol can act as the nano-reactors which solubilize zirconium oxychloride and ammonia water separately. The minute original reactors are favor to the formation of nano-sized spherical YSZ powders and the dispersibility of the powders can be controlled effectually by adjusting the weight ratio of the LiNO3 molten salt to the precursor. The phase transformation from cubic to monoclinic starts at and 500??C and finally monoclinic and cubic phase with increased crytallinity coexist at 800??C. The effect of LiNO3 molten salt in the formation of YSZ powders was also discussed.

International Nuclear Information System (INIS)

Purpose: To provide a feedwater control device capable of minimizing the adverse response of steam drum level at low power. Consitution: In order to perform feedwater control at low power by the substantial control of three factors, that is, main steam flow rate, feedwater flow rate and steam drum level, the main steam flow rate is determined from the reactor output and feedwater rate is determined from the changes in the feedwater temperature due to the mixing of waters in the reactor clean up system and feedwater. If a difference is resulted between these flow rates, a starting feedwater regulator is controlled instantly to eliminate the difference. The water level in the steam drum is used for amending the difference from the final set value of the drum water level, by which the adverse response of the steam drum level can be minimized. (Seki, T.).

Energy Technology Data Exchange (ETDEWEB)

The impacts of federal projects on wetlands should be included in documents prepared to comply with the National Environmental Policy Act (NEPA). NEPA assessments of impacts on wetlands are often related to requirements of other laws, regulations, and executive orders, such as permitting requirements under Section 404 of the Clean Water Act and those contained in Executive Order 11990, Protection of Wetlands. This paper reviews recent NEPA environmental impact statements that contained assessments of impacts on wetlands or that involved projects likely to affect wetlands. It covers documents prepared by several federal agencies, including the Army Corps of Engineers, Department of Energy, Federal Highway Administration, Soil Conservation Service, and Tennessee Valley Authority. The extent and depth of analyses of wetlands issues was found to be highly variable, both within and among ...

International Nuclear Information System (INIS)

FLOWER, a computer code recommended by USNRC for assessing the environmental impact in tidal regions, was adapted and improved so as to be suitable to deal with the influence of drift stream along seashore to the dilution of contaminants and heat in the bay mouth. And the code outputs were presented with more mid-results such as average concentrations and temperature values for all tides considered. Finally, the modified code is applied to the dispersion calculation of heat and liquid effluents from Daya Bay Nuclear Power Plant, and the impacts from routine operation of the plant on Daya Bay sea waters were given.

International Nuclear Information System (INIS)

The direct injection of steam into a water pool is a method of heat transfer used in many process industries. The amount of research in this area however is limited to the nuclear industry, with applications relating to reactor cooling systems. Electrical resistance tomography (ERT), a low cost, non-invasive and which has high temporal resolution characteristics, can be used as a visualization tool for the resistivity distribution for the steam injection into water pool such as IRWST. In this paper, three dimensional resistivity distribution of the process is obtained through ERT using iterative Gauss-Newton method. Numerical experiments are performed by assuming different resistive objects in the water pool. Numerical results show that ERT is successful in estimating the resistivity distribution for the injection of steam in the water pool

Environmental Research Database

SummaryIntended Outputs: Documentation demonstrating an improved biophysical understanding of the role of forests on low flows in the arid zone regions of India through the development and outputs from hydrological models such as Hyluc and SWAT.A documented analysis of the impacts on the poor of historical and current water management policies, including the investigation through PRA techniques of people's perceptions and beliefs of land-use/hydrological interactions, and the implications o [continued...]ObjectivesTo establish a better understanding of forest impacts on low flows and the social impact of water resources management in arid zone regions of India, and to develop tools which allow this improved understanding to be disseminated directly to stakeholders.DescriptionProject Background: Reducing river flows and groundwater tables, especially during the dry season, ...

International Nuclear Information System (INIS)

Full text: In heavy-water-moderated power reactors, tritium is primarily produced by neutron capture in deuterium nuclei in the moderator and coolant. For CANDU 6 reactors, the estimated steady-state values are #approx# 3 TBq#centre dot#kg"-"1 D_2O in the moderator and #approx# 74 GBq#centre dot#kg"-"1 D_2O in the coolant. Tritium removal is one option available to reactor operators for use in their heavy water and tritium management strategies. The WTRF is designed to remove tritium from tritiated heavy water in each of the four CANDU units at the Wolsung Site, to immobilize the tritium and to store it on site. The detritiation process is based on three steps: the first one (front-end) involves the transfer of tritium from heavy water to deuterium gas; the second one (enrichment) concentrates the tritium in a cryogenic distillation system ...

Energy Technology Data Exchange (ETDEWEB)

Current scientific knowledge of climate change and its global impact is summarized in the first four chapters. The earth's natural climate, greenhouse gases, climate prediction models, and impact of a warmer world on natural terrestrial ecosystems, agricultural ecosystems, and coastal regions are discussed. The possible impacts on Canada are described in chapter five, which considers forests, agriculture, water resources, fisheries, coastal zones, transportation, human health and well being, energy production and use, and global security. Chapter six considers ways to respond to climate change. These include enhancing knowledge of climate change, working toward a consensus on the need for action, global political response, the Canadian response, and the role of the individual. 15 refs., 35 figs.

International Nuclear Information System (INIS)

This study describes the mechanical compatibility of the direct use of spent pressurized water reactor (PWR) fuel in Canada deuterium uranium (CANDU) reactors (DUPIC) fuel, when it is loaded into a CANDU reactor. The mechanical compatibility can be assessed for the fuel management, primary heat transport system, fuel channel, and the fuel handling system in the reactor core by both the experimental and analytic methods. Because the physical dimensions of the DUPIC fuel bundle adopt the CANDU flexible (CANFLEX) fuel bundle design which has already been demonstrated for a commercial use in CANDU reactors, the experimental compatibility analyses focused on the generation of material property data and the irradiation tests of the DUPIC fuel, which are used for the computational analysis. The intermediate results of the mechanical compatibility analysis have shown ...

Energy Technology Data Exchange (ETDEWEB)

Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. Therefore, two cases are investigated: GDH impact on an adjacent GDH and its attached piping; and GDH impact on an adjacent reinforced concrete wall. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large displacements and ...

International Nuclear Information System (INIS)

... power reactors pressure tube reactors reactors THERMAL REACTORS.

Science.gov (United States)

The Army Reactor Area (ARA) II was constructed in the late 1950s as a test site for the Stationary Low Power Reactor No. 1 (SL-1). The SL-1 was a prototype power and heat source developed for use at remote military bases using a direct cycle, boiling water, natural circulation reactor designed to operate at a thermal power of 3,000 kW. The ARA II compound encompassed 3 acres and was comprised of (a) the SL-1 Reactor Building, (b) eight support facilities, (c) 50,000-gallon raw water storage tank, (d) electrical substation, (e) aboveground 1,400-gallon heating oil tank, (f) underground 1,000-gallon hazardous waste storage tank, and (g) belowground power, sewer, and water systems. The reactor building was a cylindrical, aboveground facility, 39 ft in diameter and 48 ft high. The lower portion of the building contained the ...

Energy Technology Data Exchange (ETDEWEB)

Ground-water monitoring near the Raft River site was initiated in 1974 by the IDWR. This effort consisted of semiannual chemical sampling of 22 irrigation wells near the Raft River geothermal development area. This program yielded useful baseline chemical data; however, several problems were inherent. For example, access to water pumped from the wells is limited to the irrigation season (April through September). All the wells are not continuously pumped; thus, some wells that are sampled one season cannot be sampled the next. In addition, information on well construction, completion, and production is often unreliable or not available. These data are to be supplemented by establishing a series of monitor wells in the proposed geothermal withdrawal and injection area. These wells were to be located and designed to provide data necessary for evaluating and predicting the impact of geothermal development on the Shallow ...

British Library Electronic Table of Contents (United Kingdom)

In this work, a three-dimensional multiphase non-isothermal model incorporated with a capillary-extended sub-model in gas channels is used to investigate the coupled phenomena of water and thermal transport in proton exchange membrane fuel cells. Distributions of water and temperature along the flow path in the channel are highlighted and the pros and cons of various operating temperatures are elaborated. In addition, this work also sheds light on the impacts of temperature variations of bipolar plates induced by non-uniform cooling conditions, which have been overlooked by most previous works. An important phenomenon of water distribution, dry-out at inlets and flooding at outlets (DIFO), is observed and this non-uniform distribution is revealed to be greatly influenced by the operating t...

International Nuclear Information System (INIS)

... brakes lmfbr type reactors breeder reactors epithermal reactors fast reactors

Energy Technology Data Exchange (ETDEWEB)

Sudden changes in the temperature of flowing liquids can result in transient buoyancy forces which strongly impact the flow hydrodynamics via flow stratification. These effects have been studied for the case of potential flow of stratified liquids to line sinks, but not for moderator flow in SRS reactors. Standard codes, such as TRAC and COMMIX, do not have the capability to capture the stratification effect, due to strong numerical diffusion which smears away the hot/cold fluid interface. A related problem with standard codes is the inability to track plumes injected into the liquid flow, again due to numerical diffusion. The combined effects of buoyant stratification and plume dispersion have been identified as being important in operation the Supplementary Safety System which injects neutron-poison ink into SRS reactors to provide safe shutdown in the event of safety rod failure. The MODFLOW code discussed here provides ...

Energy Technology Data Exchange (ETDEWEB)

A concept for a fast spectrum irradiation facility has been developed for insertion in the High Flux Isotope Reactor at Oak Ridge National Laboratory. The design is based on the very large fast flux that is available in this reactor combined with the use of a strongly-absorbing thermal neutron shield. The preferred concept from the several considered consists of a three-pin design surrounded by a Eu{sub 2}O{sub 3} thermal neutron shield located in the reactor flux trap. Preliminary analyses showed that this concept can provide a fast flux larger than 1x10{sup 15} n/cm{sup 2}{center_dot}s and a fast-to-thermal flux ratio greater than 300 while having an acceptable impact on the HFIR operation. Additional analyses are necessary to confirm that this design is feasible and meets the requirements for fast fuel irradiation. If the design proves to be suitable, it can provide a relatively low-cost, near-term ...

Energy Technology Data Exchange (ETDEWEB)

Condensing two-phase channel flow occurs in many industrial applications, including heating and refrigeration systems. It can also occur in certain nuclear reactor accidents. For example, during a small-break loss-of-coolant accident in a pressurized water reactor, following the partial depletion of the primary coolant, condensation of steam on the primary side of the steam generator tubes can provide a heat sink for disposal of the decay heat generated in the reactor core. Condensing two-phase flow can also play an important role in the operation of the passive emergency cooling system in the advanced simplified boiling water reactor. Here, steady-state condensation in the presence of a noncondensable in a concurrent two-phase channel flow is analyzed using a two-fluid model. The effect of noncondensables on the combined heat transfer at the liquid-gas mixture ...

Energy Technology Data Exchange (ETDEWEB)

An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on conventional design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require unconventional shapes or heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for ...

International Nuclear Information System (INIS)

Understanding of the thermal hydraulic phenomena is now the key issue in solving the severe accident problems of light water reactors. The Atomic Energy Society of Japan has organized a special committee on the evaluation of the thermal hydraulic phenomena in severe accident. The committee has continued the investigation of present status of thermal hydraulics in severe accident. Industries have completed the detailed implementation of the accident management measures, and industries have established also a self-regulatory document mainly on phase II accident management for the containment design of the future reactors. Present paper reviews the current status of evaluation activity referring to severe accident research in Japan. The phenomena included in this paper are (1) molten core behavior in lower plenum of pressure vessel, (2) fuel-coolant interaction, (3) molten core-concrete interaction, (4) direct containment ...

Energy Technology Data Exchange (ETDEWEB)

Scenarios are developed for spent fuel that is taken out of the nuclear reactor and stored for 20 years before reprocessing, and three storage techniques which use a water pool, dry cask or vault are compared with respect to their costs. The storage price (storage cost per kilogram of spent fuel), which is employed as the economic index, is calculated on the assumption that all the charge is paid when the spent fuel is brought in the storage facilities. Four scenarios are assumed for spent PWR and BWR fuels to be stored in at-reactor (AT) or away-from-reactor (AFR) facilities. The capital costs cover the buildings of the storage facilities, equipment, decommissioning, casks for transportation and storage (for cask storage) and casks for transportation (for water pool or vault storage). Costs for operation and maintenance of the facilities are also considered in evaluating these ...

Energy Technology Data Exchange (ETDEWEB)

Wastewater from a food-manufacturing plant with a low concentration of organic matter was treated at 37 centigrade in an anaerobic fluidized-bed reactor or in an upflow anaerobic sludge blanket. As the influent TOC (total organic carbon) concentration decreased, the TOC removal efficiency in these reactors decreased from 85% to 65%. The concentration of suspended solids in the effluent could be reduced to 20 mg/l, which corresponded to 7% of that in the influent. The effluent from both reactors was treated aerobically in a fixed-bed reactor. The TOC concentration and optical density of effluent from the aerobic treatment were reduced to 5 mg/l and 0.005, respectively. When the effluent treated anaerobically or aerobically was passed over an activated carbon column, the effluent TOC concentration was reduced to 2 to 3 mg/l. The conductivity in raw wastewater was remarkably reduced on an ion-exchange ...

International Nuclear Information System (INIS)

There has been recent interest in the United States concerning the loss of residual heat removal system (RHRS) under reduced coolant inventory conditions for pressurized water reactors. This issue is also of interest in the Federal Republic of Germany and an experiment was performed in the integral PKL-III experimental facility at Siemens-KWU to supply applicable data. Recently, an NRC-sponsored effort has been undertaken at the Idaho National Engineering Laboratory to identify and analyze the important thermal-hydraulic phenomena in pressurized water reactors following the long term loss-of-RHRS during reduced inventory operation. The thermal-hydraulic response of a closed reactor coolant system during such a transient is investigated in this report. Some of the specific processes investigated include: reflux condensation in the steam generators, the corresponding pressure increase ...

Energy Technology Data Exchange (ETDEWEB)

The CASTOC project addresses environmentally assisted cracking (EAC) phenomena in low alloy steels used for pressure boundary components in both Western type boiling water reactors (BWR) and Russian type pressurised water reactors (VVER). It comprises the four work packages (WP): inter-laboratory comparison test (WP1); EAC behaviour under static load (WP2), EAC behaviour under cyclic load and load transients (WP3); evaluation of the results with regard to their relevance for components in practice (WP4). The use of sophisticated test facilities and measurement techniques for the on-line detection of crack advances have provided a more detailed understanding of the mechanisms of environmentally assisted cracking and provided quantitative data of crack growth rates as a function of loading events and time, respectively. The effect of several major parameters controlling EAC was investigated with ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents the objective, scope, and status of the US Department of Energy's Materials and Structures Program to develop a data base on mechanical properties of structural materials for out-of-core structures and components for LMFBRs. Information on the development of a reference data base on materials for the reactor system, reactor enclosure system, primary heat transport system, intermediate heat transport system, and steam generator system is included. In addition, the development of the data and analyses to account for the effects of temperature and stress, as well as water/steam, sodium, and radiation environments, is described. Plans for the development of alternative materials for future out-of-core applications are presented.

Energy Technology Data Exchange (ETDEWEB)

Energy savings in the synthetic fiber industry could be realized by using autoclave reactor condensate and boiler flue gas heat recovery. The non-cellulose (polyester) production process analysis shows that condensate returning from the reactor to the steam boiler raises inlet temperature, giving a reduced fuel requirement of about 8%. Also, boiler flue gas with a sufficiently high outlet temperature for boiler feed water and combustion air preheating results in further fuel savings. The process with an economizer saves up to 8.44%, and with a combustion air preheater, 6.25%. (Author)

Energy Technology Data Exchange (ETDEWEB)

Shield measurements and four cycles of operating experience have shown the design and construction of radiation shields for the Fast Flux Test Facility (FFTF) reactor and plant to be satisfactory. A number of minor shield deficiencies were found and corrected. Most of these were associated with interfaces between components, each of which was satisfactory by itself. Preliminary evaluation of the shield measurements indicates satisfactory agreement with design calculations. Operator doses to date have been quite small, especially when compared to light water reactor experience.

Energy Technology Data Exchange (ETDEWEB)

Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter.

International Nuclear Information System (INIS)

The core bypass flow in a prismatic very high temperature reactor (VHTR) is an important design consideration and can have considerable impact on the condition of reactor core internals including fuels. The interstitial gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The occurrence of hot spots in the core and lower plenum and hot streaking in the lower plenum (regions of very hot gas flow) are affected by bypass flow. In the present study, three-dimensional computational fluid dynamic (CFD) calculations of a typical prismatic VHTR are conducted to better understand bypass flow phenomena and establish an evaluation method for the ...

Energy Technology Data Exchange (ETDEWEB)

Fundamental phenomena of condensation heat transfer at a steam-water interface have been studied related to the thermo-hydrodynamics of the emergency core cooling system for light water reactors. In this study temperature fluctuations near the interface and in the liquid phase were measured using fine thermocouples for a saturated steam-subcooled water co-current stratified two-phase flow in a nearly horizontal rectangular channel, and heat transfer coefficients were determined experimentally. The values of the condensation heat transfer coefficients in this experiment are from 6 to 40 kW/m{sup 2}K. In the regions of high Reynolds numbers, as the steam Reynolds numbers become larger, the average interfacial heat transfer coefficients tend to increase. The corelations of Nusselt numbers were obtained from the heat transfer data. (author)

Science.gov (United States)

Computer programs have been developed to define the temperature increase which would be needed to bring deep-ocean water into density equilibrium with surface water for locations where data are available. A series of continuous-flow studies on phytoplankton blooms resulting from mixtures of 80 percent deep and 20 percent surface water in 2000-liter concrete culturing vessels (''reactors'') has been completed. A quantitative determination of nutrient utilization and flow through a combined primary and secondary trophic level system has been completed. This study utilized the clam Tapes semidecussata, fed from phytoplankton grown in 80 percent deep and 20 percent surface water. An analysis of the fate of the deep water discharged from a floating OTEC plant indicates that horizontal containment of the resulting deep ...

International Nuclear Information System (INIS)

Alloy 800 has been used for steam generator (SG) tubing for more than 30 years, primarily in CANDU reactors worldwide and in reactors in Germany. Extensive laboratory testing and in-service experience suggest that the Alloy 800 tubing has excellent resistance to corrosion-related degradation under appropriate operating conditions. In planning refurbishment of nuclear plants stations, a key concern is the longevity of existing SGs up to the 60-year lifetime of the refurbished plant. The paper reviews an existing methodology based on the concept of the improvement factor, and refines its estimation based on data specific to CANDU operating conditions. The paper presents a more advanced Bayesian probabilistic approach to estimate the degradation free lifetime distribution of Alloy 800 tubing, which is used to quantify the probability of degradation during the service life and to evaluate the impact of potential occurrences of ...

International Nuclear Information System (INIS)

Alloy 800 has been used for steam generator (SG) tubing for more than 30 years, primarily in CANDU reactors and in reactors in Germany. Extensive laboratory testing and in-service experience suggest that the Alloy 800 tubing has excellent resistance to corrosion-related degradation under specified and appropriate operating conditions. In planning refurbishment of CANDU stations, a key concern is the longevity of existing SGs up to the 60 year lifetime of the refurbished plant. The paper reviews an existing methodology based on the concept of the improvement factor, and estimates it based on experimental data specific to CANDU operating conditions. The paper presents a more advanced probabilistic approach to estimate the degradation free lifetime distribution of Alloy 800 tubing, which is used to quantify the probability of degradation during the service life and to evaluate the impact of potential occurrences of degradation ...

International Nuclear Information System (INIS)

The Steam Generator (SG) serves as an interface between primary and secondary cycle in Pressurized Heavy Water Reactor (PHWR). Failure of steam generator tubes result in leaking of active heavy water in the secondary closed loop. In Tarapur Atomic Power Station-3 and 4 (TAPS- 3 and 4), Scintillator detectors are provided to detect on line heavy water leakages in SG and moderator heat exchangers by monitoring Nitrogen-16 (16N) and Oxygen-19 (19O) activities. Efficacy of detection of these activities at designed detector position on SG blow down line in presence of background radiation field is analysed theoretically. The count rate of 19O and 16N estimated at the detector position inside Reactor Building (RB) shows that detectors only respond to very high leak rates due to presence of high ambient radiation level even though sensitivity is appreciably good. For detector position in ...

International Nuclear Information System (INIS)

Argentina has two operating PHWR nuclear power plants. Atucha I NPP is a pressure vessel type heavy water reactor of 360 MW e with 25 years of operation and Embalse NPP is a pressure tube type CANDU-600 reactor of 640 MW e. Atucha II, a third plant of 600 MW e of the pressure vessel type similar to Atucha I, is being constructed. NASA (Nucleoelectrica Argentina S.A.) currently operates both nuclear power plants. The National Atomic Energy Commission (Comision Nacional de Energia Atomica - CNEA) provides operational support to the plants, including research and development assistance, and actual technical services and maintenance work in different areas. The Chemistry Department, formerly the Reactor Chemistry Department has carried out project and support activities to the plants during the past 20 years. The aim of this work is to describe the present organization and the activities in ...

Energy Technology Data Exchange (ETDEWEB)

The ability to test advanced fuels and cladding materials under reactor operating conditions in the United States is limited. The Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) and the newly expanded post-irradiation examination (PIE) capability at the ORNL Irradiated Fuels Examination Laboratory provide unique support for this type of advanced fuel/cladding development effort. The wide breadth of ORNL's fuels and materials research divisions provides all the necessary fuel development capabilities in one location. At ORNL, facilities are available from test fuel fabrication, to irradiation in HFIR under either thermal or fast reactor conditions, to a complete suite of PIEs, and to final product disposal. There are very few locations in the world where this full range of capabilities exists. New testing capabilities at HFIR have been developed that allow testing of advanced nuclear fuels and ...

Energy Technology Data Exchange (ETDEWEB)

To get a considerable reduction of the radiotoxicity due to americium, a thermal neutron fluence of 2.10{sup 22} cm{sup -2} or a fast neutron fluence of 2.10{sup 24} cm{sup -2} is required. Irradiation in a thermal neutron flux leads to lower masses of {sup 234}U and precursors and of {sup 237}Np and precursors, but to higher curium masses and much higher neutron emission rates than irradiation in a fast neutron flux. Therefore, irradiation in a fast neutron flux has preference when multiple recycling is adopted. When once-through burning is applied, irradiation in a thermal neutron flux can be applied. Then irradiation in a heavy water reactor (HWR) has preference above irradiation in a PWR or in a high temperature gas-cooled reactor (HTGR). (authors) 4 refs.

International Nuclear Information System (INIS)

The PANDA test facility at the Paul Scherrer Institute is used to study the long-term performance of the Simplified Boiling Water Reactor's passive containment cooling system. The PANDA tests demonstrate performance on a larger scale than previous tests and examine the effects of any non-uniform spatial distributions of steam and non-condensable gases in the system. The facility is in 1:1 vertical scale and 1:25 scale for volume, power etc. Extensive facility characterization tests and steady-state passive containment condenser performance tests are presented. The results of the base case test of a series of transient system behaviour tests are reviewed. The first PANDA tests exhibited reproducibility, and indicated that the Simplified Boiling Water Reactor's containment is likely to be favorably responsive and highly robust to changes in the thermal transport patterns. (orig.).

Energy Technology Data Exchange (ETDEWEB)

A fusion reactor (such as NET/ITER) which breeds its own tritium fuel requires tritium recovery, purification and separation from the other isotopes. Cyclic adsorption processes are strong candidates for several of the processes involved: amongst other advantages, they promise a low tritium inventory. A good adsorbent for such processes must have high adsorption capacity, high selectivity and very low tritium retention after each cycle. Pure zeolite powder is shown to have an excellent combination of these three properties. However, in practice problems can arise from tritium which is not removed by reactivation. In this paper we show that tritium retention in zeolites can be caused either by water retained in the zeolite structure, which can be removed by ore rigorous activation, or by water tapped on binders in commercial pellets. (orig.).

International Nuclear Information System (INIS)

Ppercase(femaxi-iv) is a computer code for the analysis of thermal and mechanical behavior of light water reactor fuel rods during steady-state and transient conditions. The main purpose of ppercase(femaxi-iv) is to calculate the stress and strain distributions in the fuel and cladding due to the pellet-cladding mechanical interaction, and the fission gas release rate during operations, especially power transients. The capability of ppercase(femaxi-iv) was extensively tested with a number of experimental results obtained in some international fuel irradiation programs. This paper provides a general description of the various models involved in ppercase(femaxi-iv) and some results of applications on the experimental data. ((orig.)).

Energy Technology Data Exchange (ETDEWEB)

A three-dimensional, continuous-energy, coupled neutron-gamma Monte Carlo model of the advanced neutron source (ANS) final preconceptual reference core design has been developed using MCNP Version 3b. This model contains the reactor core with control rods, the heavy-water reflector tank with shutdown rods and representative beam tubes, and the outer light-water poor. Eighty homogenized fuel zones per fuel element are used to represent the radical and axial {sup 235}U fuel grading. This model is the most sophisticated, physically accurate reactor physics model of the ANS currently available. The purpose of this summary is to demonstrate the MCNP methods and applications for the ANS.

Energy Technology Data Exchange (ETDEWEB)

Femaxi-iv is a computer code for the analysis of thermal and mechanical behavior of light water reactor fuel rods during steady-state and transient conditions. The main purpose of femaxi-iv is to calculate the stress and strain distributions in the fuel and cladding due to the pellet-cladding mechanical interaction, and the fission gas release rate during operations, especially power transients. The capability of femaxi-iv was extensively tested with a number of experimental results obtained in some international fuel irradiation programs. This paper provides a general description of the various models involved in femaxi-iv and some results of applications on the experimental data. ((orig.))

International Nuclear Information System (INIS)

Inherent boron dilution can occur in case of a small Break LOCA when low borated water is accumulated in the U-legs due to reflux boiling in the Steam Generator tubes after the loss of natural circulation. The restart of the natural circulation may lead to criticality because of the injection of these low borated slugs towards the core. To evaluate this potential risk, the boron concentration at the core inlet has to be known which makes necessary to estimate the mixing phenomena in the cold leg, in the downcomer and in the lower plenum: CFD calculations are required. First of all the validation of CFX5 CFD code on the relevant phenomena of inherent boron dilution has been established (UPTF TRAM C3 test). Then, an application to the 900 MW French Pressurized Water Reactor series has been performed. (authors)

Environmental Research Database

DescriptionThe switch from production-linked to environmental payments has focussed attention on the environmental impacts of farming. There is a growing awareness of the need to reduce the contamination of air with carbon dioxide, methane, ammonia and nitrogen gases (which contribute to the greenhouse effect) and to prevent the contamination of soil and water with excessive amounts of nitrogen, phosphorus and potassium. As beef production moves to become more sustainable and fully integrated with the wide [continued...

Energy Technology Data Exchange (ETDEWEB)

This article describes a new natural-gas-fired combined cycle cogeneration plant in Bellingham, Washington. The topics of the article include community impact, siting constraints, natural gas fuel, the flexibility provided by the steam turbine, the cooling tower and pumps, air-quality, noise, and cooling water system constraints, and community relations program.

Energy Technology Data Exchange (ETDEWEB)

In France, groundwater usage represents 40 per cent of volumetric use, outside of thermal power plants. Groundwater represents 60 per cent of domestic and public use, 40 per cent in the industrial sector, and is increasing in the agricultural sector where it accounts for 20 per cent. Groundwater withdrawal in France has slightly increased over the last twenty years and benefited the agricultural sector. Availability throughout the territory, the consistency of resupply and natural quality has rendered groundwater a prevailing source for drinking water. Water protection and management is important and led to the adoption of legislative and regulatory measures. The Mining Code (Code minier) allows for exploitation of underground resources starting at 10 metres. The Rural Code (Code rural) mandates the declaration of public utility for water collection for the public. Protection areas are to be provided under the Public Health ...

Energy Technology Data Exchange (ETDEWEB)

This document provides information and presents data on the energy situation in many regions of Canada. The first part deals with the petroleum and the bitumen shales of Alberta (reserves, exploitation and production, environmental impacts), the second part discusses with the hydroelectricity choice of Quebec and the 2004 crisis. The nuclear situation of Ontario is presented in the third part (nuclear park, programs, uranium reserves, research and development on Candu reactors), while the fourth part deals with the renewable energies (wind power and biomass). The canadian situation facing the Kyoto protocol is discussed in the last part. (A.L.B.)

International Nuclear Information System (INIS)

A major objective of the DOE Advanced Fuel Cycle Initiative, AFCI, is to explore technologies that may reduce the long-term environmental burden of nuclear energy through more efficient disposal of waste materials. In this work, the potential impact of the AFCI technology and its beneficial effects on waste management and its ability to meet waste management objectives are demonstrated. In addition, practical scenarios to improve permanent disposal utilization and/or reduce the temporary spent nuclear fuel (SNF) storage inventory by closing the fuel cycle through transition to fast reactor (FR) converters are also discussed. (authors)

Energy Technology Data Exchange (ETDEWEB)

SiC has been considered as a primary candidate material for a first wall component in future fusion reactor because it has been claimed that SiC has excellent high-temperature properties, good chemical stability and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, tritium trapping capacity on the surface of SiC was experimentally obtained at the temperature range of 25-800 deg. C in consideration of tritium trapping to the experimental system. The capacity, which was independent of the water vapor pressure in the gas phase and the temperature, was determined as about 10{sup 6} Bq/cm{sup 2}. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface was quantified at the temperature of 25, 500 and 700 deg. C in consideration of the behavior of tritium trapping at change of experimental condition by the numerical curve fitting method ...

British Library Electronic Table of Contents (United Kingdom)

Agricultural runoff is a major non-point source pollutant and is the leading impairment of streams and rivers in the USA. This study examined the effects of agricultural, forest and urban land cover on water quality at the watershed level. Forty-three catchments ranging from 12 to 50?km2 were selected based on a land cover gradient within Lower Kaskaskia River Watershed in Illinois. Grab samples were collected and analyzed for nutrients, bacteria, and total suspended solids (TSS). Forest land cover was included in six of the ten regression models produced. Four of these regression models were for base flow conditions, suggesting that forest land cover had a significant impact on base flow water quality. Urban land cover was also included in six of the regression models. However, the majori...

Energy Technology Data Exchange (ETDEWEB)

The Western Research Institute plan for addressing oil shale plant siting methodology calls for identifying the available resources such as oil shale, water, topography and transportation, and human resources. Restrictions on development are addressed: land ownership, land use, water rights, environment, socioeconomics, culture, health and safety, and other institutional restrictions. Descriptions of the technologies for development of oil shale resources are included. The impacts of oil shale development on the environment, socioeconomic structure, water availability, and other conditions are discussed. Finally, the Western Research Institute plan proposes to integrate these topics to develop a flow chart for oil shale plant siting. Western Research Institute has (1) identified relative topics for shale oil plant siting, (2) surveyed both published and unpublished information, and (3) identified data ...

International Nuclear Information System (INIS)

An ion chromatograph has been modified to automatically sample ten liquid water streams from the secondary side of three pressurized water reactors, Calvert Cliffs, Unit One, Rancho Seco and McGuire, Unit 1. Sampling and measurement is semicontinuous with a cycle time of approximately five hours for 10 locations with sensitivities in the range of 0.1 to 0.5 ppb. The efficiency of the condensate polishing system and subsequent transport of sodium, chloride, and sulfate around the system can be readily followed. Sulfate has been shown to have unusual volatility into the steam phase from the steam generator as well as a tendency to pass through the condensate polisher.

International Nuclear Information System (INIS)

Within the APROS simulation environment we have built a thermo-hydraulic model of a conceptual fusion power plant which is water cooled and uses lithium-lead for tritium breeding. For the safety assessment of this design we have studied an accident sequence which starts from a loss or coolant flow then leads to first wall breach and pressurisation of the vacuum vessel. Simulations have revealed strong pressure transients which can be alleviated by design changes. One goal is to verify the adequacy of the containment design: it remains intact at least 14 h without any mitigating efforts. Estimates for radioactive releases are obtained. (author)

Energy Technology Data Exchange (ETDEWEB)

Optimal neutron energy for boron neutron capture therapy (BNCT) has been studied. Epithermal neutron is superior to thermal neutrons in treating deep-seated tumors. Design of the epithermal neutron column for BNCT has been performed by using a two-dimensional transport calculation code. Aluminum and heavy water are used as moderation materials. A thermal neutron column is also designed using heavy water as thermalization material. The configuration of the facility for treatment and research of BNCT and also for basic radio-biological studies of neutrons has been presented.

Energy Technology Data Exchange (ETDEWEB)

The objective of this paper is to perform an impact analysis of the Interim Storage Cask (ISC) of the Fast Flux Test Facility (FFTF) for a 4-ft end drop. The ISC is a concrete cask used to store spent nuclear fuels. The analysis is to justify the impact force calculated by General Atomics (General Atomics, 1994) using the ILMOD computer code. ILMOD determines the maximum force developed by the concrete crushing which occurs when the drop energy has been absorbed. The maximum force, multiplied by the dynamic load factor (DLF), was used to determine the maximum g-level on the cask during a 4-ft end drop accident onto the heavily reinforced FFTF Reactor Service Building`s concrete surface. For the analysis, this surface was assumed to be unyielding and the cask absorbed all the drop energy. This conservative assumption simplified the modeling used to qualify the cask`s structural integrity for this accident condition.

International Nuclear Information System (INIS)

Analyses of the date obtained from the instrumented impact test and of its correlation with static and dynamic J integral values and various tensile properties are made in this study. It is shown that a dynamic bending yield load recorded in the instrumented Charpy V test can be easily converted to a dynamic tensile yield stress using Server's equation. It is also possible to estimate a true fracture strain, COD value, and SZW easily if the load point displacement is recorded. Temperature dependency of Charpy V energy and J integral values is rather well simulated by a curve fitting method. However, a half value transition temperture obtained in that method has no physical meaning. Dynamic J sub(ID) is larger than a static J sub(IC) in the ductile fracture range in this study. This rise is proportional to the yield stress ratio #sigma#sub(yd)/#sigma#sub(y)(--1.2-1.3). It is found, therefore, that the following relation exists in the both cases; J ...

International Nuclear Information System (INIS)

The Steam Generator (SG) serves as an interface between primary and secondary cycle in Pressurized Heavy Water Reactor (PHWR). Failure of steam generator tubes result in leaking of active heavy water in the secondary closed loop. In Tarapur Atomic Power Station-3 and 4 (TAPS- 3 and 4), Scintillator detectors are provided to detect on line heavy water leakages in SG and moderator heat exchangers by monitoring Nitrogen-16 ("1"6N) and Oxygen-19 ("1"90) activities. Efficacy of detection of these activities at designed detector position on SG blow down line in presence of background radiation field is analysed theoretically. The count rate of "1"9O and "1"6N estimated at the detector position inside Reactor Building (RB) shows that detectors only respond to very high leak rates due to presence of high background even though sensitivity is appreciably good. For detector position out side ...

International Nuclear Information System (INIS)

The first Russian reprocessing facility, known as RT-1 (located at PA-Mayak in Ural region) was started on the radiochemical plant base in 1977. Nowadays RT-1 is the sole operating reprocessing plant in Russia. The main features of RT-1 is its broad spectrum of reprocessing spent nuclear fuels (SNF). The following spent fuel types are reprocessed: -) SNF from PWR reactors (WWER-440) and FB reactor (BN-600); -) SNF of transport ship reactors; -) production reactors SNF; -) research reactor spent nuclear fuel. The world-known technological processes are used at RT-1, but there are the following distinctive features. First, the universality of the three technological lines which allows not only the reprocessing of various SNF kinds, but also to implement the combined reprocessing of some types of them. Secondly, extraction of neptunium during SNF reprocessing which is used to implement ...

International Nuclear Information System (INIS)

Since 1988, the Expertise group of Molecular and Cellular Biology (MCB) is an important partner in the development of the Micro-Ecological Life Support System Alternative (MELiSSA). The MELiSSA was designed to allow a small crew to survive on an Antarctic, lunar or Mars outpost, and is a joint research project currently fostered by the European Space Agency, ESA. The MELiSSA functions through a series of five interconnected compartments, of which four are microbial bioreactors and was engineered to degrade organic waste, regenerate the outpost's atmosphere and water, and provide the crew with an additional vegetarian diet. The bioreactor of the third compartment provides the edible cyanobacteria and plants of the fourth compartment with nitrate instead of ammonium as a source of nitrogen. The two bacteria responsible for the biological transformation of ammonium to nitrate (nitrification) are Nitrosomonas europaea and Nitrobacter winogradskyi. Since all ...

International Nuclear Information System (INIS)

In Japan, the development of next-generation Light Water Reactor has been launched since April 2008. The development program will be completed in 2015. The purpose of development is to cope with the replacement for existing nuclear power plants after 2030 in Japan and the expanding demand for nuclear power in the world; 'Nuclear Renaissance.' The reactor also aims to be global standard at around 2030. The requirements for global standard and domestic users have been investigated through the feasibility study of past 2 years, 2006-2007, and six innovative features or 'Core-Concepts' were established as follows. A) Reactor core system with uranium enrichment above 5% for significant decrease of spent fuel discharge and prominent higher availability B) Long-life materials and innovative water chemistry technologies for 80 years plant lifetime and significant reduction of occupational ...

Energy Technology Data Exchange (ETDEWEB)

One of the issues identified in the US Nuclear Regulatory Commission`s Nuclear Plant Aging Research program plan is the need to understand the state of ``mothballed`` or other out-of-service equipment to ensure subsequent safe operation. Programs for proper storage and preservation of materials and components are required by NRC regulations (10 CFR 50, Appendix B). However, materials and components have been seriously degraded due to improper storage, protection, or layup, at facilities under construction as well as those with operating licenses. Pacific Northwest Laboratory has evaluated management of aging for unstarted or mothballed nuclear power plants. The investigations revealed that no uniform guidance in the industry addresses reactor layup. In each case investigated, layup was not initiated in a timely manner, primarily because of schedule uncertainty. Hence, it is reasonable to assume that this delay resulted in accelerated aging of some ...

International Nuclear Information System (INIS)

A series of real-time, neutron radiography, experiments are ongoing at the Texas A and M Nuclear Science Center Reactor (NSCR). These tests determine the resolving capabilities for radiographic imaging of two phase water and air flow regimes through small diameter flow channels. Though both film and video radiographic imaging is available, the real-time video imaging was selected to capture the dynamic flow patterns with results that continue to improve. (author)

International Nuclear Information System (INIS)

The paper reviews the formation of minor actinides in light water and fast reactors, as well as the current status and recent improvements in the nuclear data for minor actinides, and compares recently evaluated data with experimental results. The paper also describes the qualification of nuclear data by post-irradiation analysis and integral measurements in fast critical assemblies. (author).

International Nuclear Information System (INIS)

Some of the origins of corrosion encountered in the secondary side of pressurized water reactor steam generators are:-sludge accumulation (a mixture of metal oxides, primarily magnetite and copper) on tube sheet and attack of tube support plates by aggressive impurities leading to denting. Although Electricite de France has not suffered from these problems, it has developed a chemical cleaning process to dissolve corrosion products at both locations. (author).

International Nuclear Information System (INIS)

Late last year the Wolsung Candu in Korea suffered an incident which resulted in heavy water being released from the primary system into the containment. With the unit now back at full power, this article examines the causes of the incident and the action which is being taken to prevent it happening again. (author).

Energy Technology Data Exchange (ETDEWEB)

In connection with the Public Inquiry into the CEGB proposal to build a pressurised water reactor at Sizewell in Suffolk, the case for nuclear power is examined under the headings: the economics of nuclear power - how they would like them to be; systems analysis - net effective cost; CEGB prejudices the results (comparison with coal-fired plants; forecasting on various assumptions); discounting future costs; back-end costs soar (reprocessing); real reprocessing costs; AGR costs balloon.

Science.gov (United States)

A technical committee reported on: (1) proposed water quality objectives for the San Joaquin River Basin; (2) proposed effluent limitations for agricultural drainage discharges in the basin to achieve these objectives; and (3) a proposal to regulate these discharges. The costs and economic impact of achieving various alternative water quality objectives were also evaluated. The information gathered by the technical committee will be used by the Regional Board along with other information in their review of the San Joaquin River Basin Water Quality Control Plan and their actions to regulate agricultural drainage in the San Joaquin Valley. The results of the Technical Committee's efforts as reported in Regulation of Agricultural Drainage to the San Joaquin River, August 1987. Based on the available information, the improvement in water quality resulting from implementation of ...

International Nuclear Information System (INIS)

This paper consists of shielding analysis of steel balls and water filled end shields of Indian Pressurized Heavy Water Reactors (PHWRs). The material composition inside lattice tube is entirely different neutronically as compared with the composition of end-shield. Due to variation of material composition in radial and axial directions and complex geometry, it is necessary to carry out 3-D analysis for reasonable prediction of neutron flux and gamma dose rates. In the present paper, shielding analysis of end-shield for 540 MWe PHWR has been carried out during reactor operating and shutdown conditions using Monte-Carlo code MCNP. Furthermore materials on the periphery and central portion of end shield are different. Therefore the analysis was carried out separately for annular portion and central portion of end shield. The dominating streaming paths through end shields were studied. Predictions compare ...

Energy Technology Data Exchange (ETDEWEB)

This paper reports on three-dimensional continuous-energy coupled neutron-gamma Monte Carlo models of the Advanced Neutron Source (ANS) final preconceptual and conceptual reference core designs developed using the Monte Carlo Neutron and Photon transport code (MCNP) Version 3b. These models contain the reactor core with control rods, the heavy water reflector tank with shutdown rods and some beam tubes, and the outer light water pool. Eighty homogenized fuel zones per fuel element are used to represent the radial and axial {sup 235}U fuel distribution. These models are the most sophisticated, physically accurate reactor physics models of the ANS currently available. The use of MCNP methods and applications to the ANS are demonstrated. Beam tube studies, coolant voiding studies, and many criticality studies have already been performed, as have studies with variance reduction techniques. In comparison ...