Measuring Single Event Upsets in the ATLAS Inner Tracker

CERN Multimedia

CERN. Geneva

2015-01-01

When the HL-LHC starts collecting data, the electronics inside will be subject to massive amounts of radiation. As a result, single event upsets could pose a threat to the ATLAS readout chain. The ABC130, a prototype front-end ASIC for the ATLAS inner tracker, must be tested for its susceptibility to single event upsets.

Single Event Upset Studies Using the ATLAS SCT

CERN Document Server

Dafinca, A; The ATLAS collaboration; Weidberg, A R

2014-01-01

Single Event Upsets (SEU) are expected to occur during high luminosity running of the ATLAS SemiConductor Tracker (SCT). The SEU cross sections were measured in pion beams with momenta in the range 200 to 465 MeV/c and proton test beams at 24 GeV/c but the extrapolation to LHC conditions is non-trivial because of the range of particle types and momenta. The SEUs studied occur in the p-i-n photodiode and the registers in the ABCD chip. Comparisons between predicted SEU rates and those measured from ATLAS data are presented. The implications for ATLAS operation are discussed

TDRS-1 single event upsets and the effect of the space environment

International Nuclear Information System (INIS)

Wilkinson, D.C.; Daughtridge, S.C.; Stone, J.L.; Sauer, H.H.; Darling, P.

1991-01-01

The systematic recording of Single Event Upsets on TDRS-1 from 1984 to 1990 allows correlations to be drawn between those upsets and the space environment. In this paper, ground based neutron monitor data are used to illustrate the long-term relationship between galactic cosmic rays and TDRS-1 upsets. The short-term effects of energetic solar particles are illustrated with space environment data from GOES-7

Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets in a NAND Flash Memory

Science.gov (United States)

Chen, Dakai; Wilcox, Edward; Ladbury, Raymond L.; Kim, Hak; Phan, Anthony; Seidleck, Christina; Label, Kenneth

2016-01-01

We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found that the single-event upset (SEU) cross section varied inversely with cumulative fluence. We attribute the effect to the variable upset sensitivities of the memory cells. Furthermore, the effect impacts only single cell upsets in general. The rate of multiple-bit upsets remained relatively constant with fluence. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, traditional SEE testing techniques may underestimate the on-orbit event rate for a device with variable upset sensitivity.

Single Event Upset Studies Using the ATLAS SCT

CERN Document Server

Weidberg, A R; The ATLAS collaboration

2013-01-01

Single Event Upsets (SEU) are expected to occur during high luminosity running of the ATLAS SemiConductor Tracker (SCT). The SEU cross sections were measured in pion beams with momenta in the range 200 to 465 MeV/c and proton test beams at 24 GeV/c but the extrapolation to LHC conditions is non-trivial because of the range of particle types and momenta. The SEUs studied occur in the \\emph{p-i-n} photodiode and the registers in the ABCD chip. Comparisons between predicted SEU rates and those measured from ATLAS data are presented. The implications for ATLAS operation are discussed.

Modeling and control of a DC upset resistance butt welding process

NARCIS (Netherlands)

Naus, G.J.L.; Meulenberg, R.; Molengraft, van de M.J.G.

2007-01-01

This paper presents the analysis and synthesis of modeling and control of the DC upset resistance butt welding process used in rim production lines. A new control strategy is developed, enabling active control of the welding seam temperature and the upset size. As a result, set-up times and energy

Upset Over Sexual versus Emotional Infidelity Among Gay, Lesbian, Bisexual, and Heterosexual Adults.

Science.gov (United States)

Frederick, David A; Fales, Melissa R

2016-01-01

One hypothesis derived from evolutionary perspectives is that men are more upset than women by sexual infidelity and women are more upset than men by emotional infidelity. The proposed explanation is that men, in contrast to women, face the risk of unwittingly investing in genetically unrelated offspring. Most studies, however, have relied on small college or community samples of heterosexual participants. We examined upset over sexual versus emotional jealousy among 63,894 gay, lesbian, bisexual, and heterosexual participants. Participants imagined which would upset them more: their partners having sex with someone else (but not falling in love with them) or their partners falling in love with someone else (but not having sex with them). Consistent with this evolutionary perspective, heterosexual men were more likely than heterosexual women to be upset by sexual infidelity (54 vs. 35 %) and less likely than heterosexual women to be upset by emotional infidelity (46 vs. 65 %). This gender difference emerged across age groups, income levels, history of being cheated on, history of being unfaithful, relationship type, and length. The gender difference, however, was limited to heterosexual participants. Bisexual men and women did not differ significantly from each other in upset over sexual infidelity (30 vs. 27 %), regardless of whether they were currently dating a man (35 vs. 29 %) or woman (28 vs. 20 %). Gay men and lesbian women also did not differ (32 vs. 34 %). The findings present strong evidence that a gender difference exists in a broad sample of U.S. adults, but only among heterosexuals.

Experimental Research and Method for Calculation of 'Upsetting-with-Buckling' Load at the Impression-Free (Dieless Preforming of Workpiece

Directory of Open Access Journals (Sweden)

Kukhar Volodymir

2018-01-01

Full Text Available This paper presents the results of experimental studies of load characteristic changes during the upsetting of high billets with the upsetting ratio (height to diameter ratio from 3.0 to 6.0, which is followed by buckling. Such pass is an effective way of preforming the workpiece for production of forgings with a bended axis or dual forming, and belongs to impression-free (dieless operation of bulk forming. Based on the experimental data analysis, an engineering method for calculation of workpiece pre-forming load as a maximum buckling force has been developed. The analysis of the obtained data confirmed the possibility of performing of this pre-forming operation on the main forging equipment, since the load of shaping by buckling does not exceed the load of the dieforging.

Experimental Research and Method for Calculation of 'Upsetting-with-Buckling' Load at the Impression-Free (Dieless) Preforming of Workpiece

Science.gov (United States)

Kukhar, Volodymir; Artiukh, Victor; Prysiazhnyi, Andrii; Pustovgar, Andrey

2018-03-01

This paper presents the results of experimental studies of load characteristic changes during the upsetting of high billets with the upsetting ratio (height to diameter ratio) from 3.0 to 6.0, which is followed by buckling. Such pass is an effective way of preforming the workpiece for production of forgings with a bended axis or dual forming, and belongs to impression-free (dieless) operation of bulk forming. Based on the experimental data analysis, an engineering method for calculation of workpiece pre-forming load as a maximum buckling force has been developed. The analysis of the obtained data confirmed the possibility of performing of this pre-forming operation on the main forging equipment, since the load of shaping by buckling does not exceed the load of the dieforging.

Corrected multiple upsets and bit reversals for improved 1-s resolution measurements

International Nuclear Information System (INIS)

Brucker, G.J.; Stassinopoulos, E.G.; Stauffer, C.A.

1994-01-01

Previous work has studied the generation of single and multiple errors in control and irradiated static RAM samples (Harris 6504RH) which were exposed to heavy ions for relatively long intervals of time (minute), and read out only after the beam was shut off. The present investigation involved storing 4k x 1 bit maps every second during 1 min ion exposures at low flux rates of 10 3 ions/cm 2 -s in order to reduce the chance of two sequential ions upsetting adjacent bits. The data were analyzed for the presence of adjacent upset bit locations in the physical memory plane, which were previously defined to constitute multiple upsets. Improvement in the time resolution of these measurements has provided more accurate estimates of multiple upsets. The results indicate that the percentage of multiples decreased from a high of 17% in the previous experiment to less than 1% for this new experimental technique. Consecutive double and triple upsets (reversals of bits) were detected. These were caused by sequential ions hitting the same bit, with one or two reversals of state occurring in a 1-min run. In addition to these results, a status review for these same parts covering 3.5 years of imprint damage recovery is also presented

Single event upset susceptibilities of latchup immune CMOS process programmable gate arrays

Science.gov (United States)

Koga, R.; Crain, W. R.; Crawford, K. B.; Hansel, S. J.; Lau, D. D.; Tsubota, T. K.

Single event upsets (SEU) and latchup susceptibilities of complementary metal oxide semiconductor programmable gate arrays (CMOS PPGA's) were measured at the Lawrence Berkeley Laboratory 88-in. cyclotron facility with Xe (603 MeV), Cu (290 MeV), and Ar (180 MeV) ion beams. The PPGA devices tested were those which may be used in space. Most of the SEU measurements were taken with a newly constructed tester called the Bus Access Storage and Comparison System (BASACS) operating via a Macintosh II computer. When BASACS finds that an output does not match a prerecorded pattern, the state of all outputs, position in the test cycle, and other necessary information is transmitted and stored in the Macintosh. The upset rate was kept between 1 and 3 per second. After a sufficient number of errors are stored, the test is stopped and the total fluence of particles and total errors are recorded. The device power supply current was closely monitored to check for occurrence of latchup. Results of the tests are presented, indicating that some of the PPGA's are good candidates for selected space applications.

Analysis of Control Strategies for Aircraft Flight Upset Recovery

Science.gov (United States)

Crespo, Luis G.; Kenny, Sean P.; Cox, David E.; Muri, Daniel G.

2012-01-01

This paper proposes a framework for studying the ability of a control strategy, consisting of a control law and a command law, to recover an aircraft from ight conditions that may extend beyond the normal ight envelope. This study was carried out (i) by evaluating time responses of particular ight upsets, (ii) by evaluating local stability over an equilibrium manifold that included stall, and (iii) by bounding the set in the state space from where the vehicle can be safely own to wings-level ight. These states comprise what will be called the safely recoverable ight envelope (SRFE), which is a set containing the aircraft states from where a control strategy can safely stabilize the aircraft. By safe recovery it is implied that the tran- sient response stays between prescribed limits before converging to a steady horizontal ight. The calculation of the SRFE bounds yields the worst-case initial state corresponding to each control strategy. This information is used to compare alternative recovery strategies, determine their strengths and limitations, and identify the most e ective strategy. In regard to the control law, the authors developed feedback feedforward laws based on the gain scheduling of multivariable controllers. In regard to the command law, which is the mechanism governing the exogenous signals driving the feed- forward component of the controller, we developed laws with a feedback structure that combines local stability and transient response considera- tions. The upset recovery of the Generic Transport Model, a sub-scale twin-engine jet vehicle developed by NASA Langley Research Center, is used as a case study.

Upset in Response to a Sibling’s Partner’s Infidelity

OpenAIRE

Dafni Hellstrand; Elisavet Chrysochoou

2015-01-01

Existing evidence suggests that the psychological design of romantic jealousy differs for men and women: Men are more likely than women to report greater upset in response to a partner’s sexual than emotional infidelity, whereas women are more likely than men to report greater upset in response to a partner’s emotional than sexual infidelity. However, the observed sex difference can be explained after the fact by both an evolutionary analysis of past reproductive costs and a social constructi...

Fabrication and properties of Y-Ba-Cu-O high Tc superconductor by upset-forging method

International Nuclear Information System (INIS)

Chang, Ho Jung; Kang, Kae Myung; Song, Jin Tae

1990-01-01

YBa 2 Cu 3 O 7-x oxide superconductors was fabricated by sintering process and upset-forging method, respectively, and microstructures and conduction properties were compared. There was no difference in crystal structure the (001) x-ray reflection presumably due to preferred crystal orientation of the YBa 2 Cu 3 O 7-x superconductor. Furthermore, the grain size of the 123-phase increased as the reduction ratio became larger during the upset-forging. The critical temperature for zero resistivity of both samples was almost the same, i.e., about 90K. These results have demonstrated the potential of producing YBa 2 Cu 3 O 7-x superconducting wire or tape effectively using a upset-forging method. The critical current density of the upset-forged sample, however, was lower than that of the sintered one, which fact might be ascribed to microcrack formation during fast upset-forging. (Author)

Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets of NAND Flash Memory

Science.gov (United States)

Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Kim, Hak; Phan, Anthony; Seidleck, Christina; LaBel, Kenneth

2016-01-01

We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found the single-event upset (SEU) cross section varied inversely with fluence. The SEU cross section decreased with increasing fluence. We attribute the effect to the variable upset sensitivities of the memory cells. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, heavy ion irradiation of devices with variable upset sensitivity distribution using typical fluence levels may underestimate the cross section and on-orbit event rate.

Proton upset rate prediction: a new sensitive volume concept definition

International Nuclear Information System (INIS)

Inguimbert, Christophe

1999-01-01

We present a model for predicting proton induced single event upset rate. The approach uses heavy ion cross section experimental data combined with nuclear reaction calculations in order to determine the proton upset cross section. The p+Si nuclear reaction as well as the Si(p, p)Si Coulombic scattering are described. The upset rate calculation depends on the energy deposited available in the charge collection region (sensitive region). This region is treated as a rectangular parallelepiped of thickness d at depth h. The sensitive thickness d is used as an input parameter in our model we have developed an original method to probe the sensitive region to evaluate d with reasonable accuracy d. We use short range ions and we propose a new mathematical analysis of these experimental data to determine h and d. This method consists in de-convoluting the heavy ion upset cross section σ_S_E_U(r) by the LET function of the incident ion LET(r) (r is the range of the incident ion). Our results are in relatively good agreement with other models. The accuracy of the method allows us to discuss the validity of the sensitive volume concept. Furthermore, we extrapolate an internal gain factor α that permit to take into account the charge collection mechanisms. α and d serve for quick and reasonably accurate prediction of proton induced SEU cross section in microelectronic devices. (author) [fr

Lithium control during normal operation

International Nuclear Information System (INIS)

Suryanarayan, S.; Jain, D.

2010-01-01

Periodic increases in lithium (Li) concentrations in the primary heat transport (PHT) system during normal operation are a generic problem at CANDU® stations. Lithiated mixed bed ion exchange resins are used at stations for pH control in the PHT system. Typically tight chemistry controls including Li concentrations are maintained in the PHT water. The reason for the Li increases during normal operation at CANDU stations such as Pickering was not fully understood. In order to address this issue a two pronged approach was employed. Firstly, PNGS-A data and information from other available sources was reviewed in an effort to identify possible factors that may contribute to the observed Li variations. Secondly, experimental studies were carried out to assess the importance of these factors in order to establish reasons for Li increases during normal operation. Based on the results of these studies, plausible mechanisms/reasons for Li increases have been identified and recommendations made for proactive control of Li concentrations in the PHT system. (author)

Effect of Friction on Barreling during cold Upset Forging of Aluminium 6082 Alloy Solid cylinders

Science.gov (United States)

Priyadarshini, Amrita; Kiran, C. P.; Suresh, K.

2018-03-01

Friction is one of the significant factors in forging operations since it affects metal flow in the die, forming load, strain distribution, tool and die life, surface quality of the product etc. In upset forging, the frictional forces at the die-workpiece interface oppose the outward flow of the material due to which the specimen develops a barrel shape. As a result, the deformation becomes non-uniform or inhomogeneous which is undesirable. Barreling can be reduced by applying effective lubricant on the surface of the platens. The objective of the present work is to study experimentally the effect of various frictional conditions (dry, grease, mineral oil) on barreling during upset forging of aluminum 6082 solid cylinders of different aspect ratio (length/diameter: 0.5, 0.75, 1). The friction coefficients are determined using the ring compression test. Curvature of barrel is determined based on the assumption that the curvature of the barrel follows the geometry of circular arc.

Dynamic effect in ultrasonic assisted micro-upsetting

Science.gov (United States)

Presz, Wojciech

2018-05-01

The use of ultrasonic assistance in microforming is becoming more and more popular. Mainly due to the beneficial effect of vibrations on the flow of plastic deformation reported already in the 50s of the last century. The influence is of two types: surface and volume. The surface effect is mainly the reduction of friction forces, and volumetric is the impact on the dislocation movement and even on phase transitions. The work focuses on the dynamic aspect of vibration assisted microforming. The use of ultrasonic vibrations at a frequency of 20 kHz and an amplitude of 16 µm, in the micro-upsetting process of an aluminum sample resulted in a high concentration of strain on both ends of the sample - at 14% of the height on both sides. There was observed (in relation to deformations of the sample without vibrations) 150-250% increase and a 50% decrease in strain in the center of the sample. At the same time, the larger deformations occurred from the impact side of the punch. Analyzing the course of forces of the upsetting process in the loading and unloading phase as well as the process of breaking glass samples, the spring deflections of key system elements and their natural frequencies were determined or calculated. Based on the determined or calculated parameters of the test stand, it was shown that during the micro-upsetting process the punch may detach from the sample surface and this is the main reason for the phenomena occurring. Detach of the punch is also the cause of the observed instability of the measurement of force, which should be considered unbelievable in such a situation.

Microstructure and mechanical properties of resistance upset butt welded 304 austenitic stainless steel joints

International Nuclear Information System (INIS)

Sharifitabar, M.; Halvaee, A.; Khorshahian, S.

2011-01-01

Graphical abstract: Three different microstructural zones formed at different distances from the joint interface in resistance upset butt welding of 304 austenitic stainless steel. Highlights: → Evaluation of microstructure in resistance upset welding of 304 stainless steel. → Evaluation of welding parameters effects on mechanical properties of the joint. → Introducing the optimum welding condition for joining stainless steel bars. -- Abstract: Resistance upset welding (UW) is a widely used process for joining metal parts. In this process, current, time and upset pressure are three parameters that affect the quality of welded products. In the present research, resistance upset butt welding of 304 austenitic stainless steel and effect of welding power and upset pressure on microstructure, tensile strength and fatigue life of the joint were investigated. Microstructure of welds were studied using scanning electron microscopy (SEM). X-ray diffraction (XRD) analysis was used to distinguish the phase(s) that formed at the joint interface and in heat affected zone (HAZ). Energy dispersive spectroscopy (EDS) linked to the SEM was used to determine chemical composition of phases formed at the joint interface. Fatigue tests were performed using a pull-push fatigue test machine and the fatigue properties were analyzed drawing stress-number of cycles to failure (S-N) curves. Also tensile strength tests were performed. Finally tensile and fatigue fracture surfaces were studied by SEM. Results showed that there were three different microstructural zones at different distances from the joint interface and delta ferrite phase has formed in these regions. There was no precipitation of chromium carbide at the joint interface and in the HAZ. Tensile and fatigue strengths of the joint decreased with welding power. Increasing of upset pressure has also considerable influence on tensile strength of the joint. Fractography of fractured samples showed that formation of hot spots at

Charge collection and SEU (Single Event Upset) mechanisms

International Nuclear Information System (INIS)

Musseau, O.

1994-01-01

The purpose of this paper is to review the mechanisms of single event upset in microelectronic devices due to interaction with cosmic ions. Experimental and theoretical results are presented, and actual questions and problems are discussed. A brief introduction recalls the creation of the dense plasma of electron-hole pairs along the ion track. The basic processes for charge collection in a simple np junction (drift and diffusion) are presented. The funneling-field effect is discussed and experimental results are compared to numerical simulations and semi-empirical models. Charge collection in actual microelectronic structures is then presented. Single event upset of memory cells is discussed, based on numerical and experimental data. The main parameters for device characterization are presented. From the physical interpretation of charge collection mechanisms, the intrinsic sensitivity of various microelectronic technologies is determined and compared to experimental data. Scaling laws and future trends are discussed. (author)

Statistics and methodology of multiple cell upset characterization under heavy ion irradiation

International Nuclear Information System (INIS)

Zebrev, G.I.; Gorbunov, M.S.; Useinov, R.G.; Emeliyanov, V.V.; Ozerov, A.I.; Anashin, V.S.; Kozyukov, A.E.; Zemtsov, K.S.

2015-01-01

Mean and partial cross-section concepts and their connections to multiplicity and statistics of multiple cell upsets (MCUs) in highly-scaled digital memories are introduced and discussed. The important role of the experimental determination of the upset statistics is emphasized. It was found that MCU may lead to quasi-linear dependence of cross-sections on linear energy transfer (LET). A new form of function for interpolation of mean cross-section dependences on LET has been proposed

A Model for Microcontroller Functionality Upset Induced by External Pulsed Electromagnetic Irradiation

Science.gov (United States)

2016-11-21

AFRL-RD-PS- AFRL-RD-PS- TN-2016-0003 TN-2016-0003 A Model for Microcontroller Functionality Upset Induced by External Pulsed Electromagnetic...TYPE Technical Note 3. DATES COVERED (From - To) 22-11-2015 – 21-11-2016 4. TITLE AND SUBTITLE A Model for Microcontroller Functionality Upset Induced by... microcontroller (µC) subjected to external irradiation by a narrowband electromagnetic (EM) pulse. In our model, the state of a µC is completely specified by

Neutron-induced single event upsets in static RAMS observed at 10 km flight altitude

International Nuclear Information System (INIS)

Olsen, J.; Becher, P.E.; Fynbo, P.B.; Raaby, P. Schultz, J.

1993-01-01

Neutron induced single event upsets (SEUs) in static memory devices (SRAMs) have so far been seen only in laboratory environments. The authors report observations of 14 neutron induced SEUs at commercial aircraft flight altitudes as well. The observed SEU rate at 10 km flight altitude based on exposure of 160 standard 256 Kbit CMOS SRAMs is 4.8 · 10 -8 upsets/bit/day. In the laboratory 117 SRAMs of two different brands were irradiated with fast neutrons from a Pu-Be source. A total of 176 SEUs have been observed, among these are two SEU pairs. The upset rates from the laboratory tests are compared to those found in the airborne SRAMS

Upset in Response to a Sibling’s Partner’s Infidelity

Directory of Open Access Journals (Sweden)

Dafni Hellstrand

2015-08-01

Full Text Available Existing evidence suggests that the psychological design of romantic jealousy differs for men and women: Men are more likely than women to report greater upset in response to a partner’s sexual than emotional infidelity, whereas women are more likely than men to report greater upset in response to a partner’s emotional than sexual infidelity. However, the observed sex difference can be explained after the fact by both an evolutionary analysis of past reproductive costs and a social constructionist analysis of social and gender role training. Attempting to disentangle these competing perspectives, researchers have measured participants’ upset in response to a sibling’s or a child’s partner’s infidelities. In contrast to what a socialization perspective would predict, participants’ sex did not seem to affect their responses; the key variable was the sex of the sibling or the child, in line with a heuristic application of the evolutionary perspective. The present study attempted not only to test these competing hypotheses but also to extend previous work by involving participants with a gay or lesbian sibling and examining whether participants’ responses are triggered by their sibling’s or sibling’s partner’s sex. In line with an evolutionary perspective, participants’ sex did not assert an effect on their responses. The key variable seemed to be the sex of the sibling (rather than the sex of the sibling’s partner, with participants reporting greater levels of upset in response to the sexual than emotional infidelity of a gay brother’s partner and to the emotional than sexual infidelity of a lesbian sister’s partner. The ensuing discussion offers suggestions for future work on sex-specific triggers of jealousy.

Quantum arrival times and operator normalization

International Nuclear Information System (INIS)

Hegerfeldt, Gerhard C.; Seidel, Dirk; Gonzalo Muga, J.

2003-01-01

A recent approach to arrival times used the fluorescence of an atom entering a laser illuminated region, and the resulting arrival-time distribution was close to the axiomatic distribution of Kijowski, but not exactly equal, neither in limiting cases nor after compensation of reflection losses by normalization on the level of expectation values. In this paper we employ a normalization on the level of operators, recently proposed in a slightly different context. We show that in this case the axiomatic arrival-time distribution of Kijowski is recovered as a limiting case. In addition, it is shown that Allcock's complex potential model is also a limit of the physically motivated fluorescence approach and connected to Kijowski's distribution through operator normalization

Stability and performance analysis of a jump linear control system subject to digital upsets

Science.gov (United States)

Wang, Rui; Sun, Hui; Ma, Zhen-Yang

2015-04-01

This paper focuses on the methodology analysis for the stability and the corresponding tracking performance of a closed-loop digital jump linear control system with a stochastic switching signal. The method is applied to a flight control system. A distributed recoverable platform is implemented on the flight control system and subject to independent digital upsets. The upset processes are used to stimulate electromagnetic environments. Specifically, the paper presents the scenarios that the upset process is directly injected into the distributed flight control system, which is modeled by independent Markov upset processes and independent and identically distributed (IID) processes. A theoretical performance analysis and simulation modelling are both presented in detail for a more complete independent digital upset injection. The specific examples are proposed to verify the methodology of tracking performance analysis. The general analyses for different configurations are also proposed. Comparisons among different configurations are conducted to demonstrate the availability and the characteristics of the design. Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 61403395), the Natural Science Foundation of Tianjin, China (Grant No. 13JCYBJC39000), the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, China, the Tianjin Key Laboratory of Civil Aircraft Airworthiness and Maintenance in Civil Aviation of China (Grant No. 104003020106), and the Fund for Scholars of Civil Aviation University of China (Grant No. 2012QD21x).

Operational behaviour of a reactor normal operation and disturbances

International Nuclear Information System (INIS)

Geyer, K.H.

1982-01-01

During normal operation, the following topics are dealt with: primary and secondary coolant circuits - full load operation - start-up and shutdown - steady state part load diagramm. During disturbances and incidents, the following procedures are discussed: identification and detection of the events - automatic actions - manual actions of the operator - provided indications - explanation of actuated systems - basic information of reactor protection system. (RW)

Relationship between single-event upset immunity and fabrication processes of recent memories

International Nuclear Information System (INIS)

Nemoto, N.; Shindou, H.; Kuboyama, S.; Matsuda, S.; Itoh, H.; Okada, S.; Nashiyama, I.

1999-01-01

Single-Event upset (SEU) immunity for commercial devices were evaluated by irradiation tests using high-energy heavy ions. We show test results and describe the relationship between observed SEU and structures/fabrication processes. We have evaluated single-even upset (SEU) tolerance of recent commercial memory devices using high energy heavy ions in order to find relationship between SEU rate and their fabrication process. It was revealed that the change of the process parameter gives much effect for the SEU rate of the devices. (authors)

In-flight and ground testing of single event upset sensitivity in static RAMs

International Nuclear Information System (INIS)

Johansson, K.; Dyreklev, P.; Granbom, B.; Calvet, C.; Fourtine, S.; Feuillatre, O.

1998-01-01

This paper presents the results from in-flight measurements of single event upsets (SEU) in static random access memories (SRAM) caused by the atmospheric radiation environment at aircraft altitudes. The memory devices were carried on commercial airlines at high altitude and mainly high latitudes. The SEUs were monitored by a Component Upset Test Equipment (CUTE), designed for this experiment. The in flight results are compared to ground based testing with neutrons from three different sources

Causal relationships between solar proton events and single event upsets for communication satellites

Science.gov (United States)

Lohmeyer, W. Q.; Cahoy, K.; Liu, Shiyang

In this work, we analyze a historical archive of single event upsets (SEUs) maintained by Inmarsat, one of the world's leading providers of global mobile satellite communications services. Inmarsat has operated its geostationary communication satellites and collected extensive satellite anomaly and telemetry data since 1990. Over the course of the past twenty years, the satellites have experienced more than 226 single event upsets (SEUs), a catch-all term for anomalies that occur in a satellite's electronics such as bit-flips, trips in power supplies, and memory changes in attitude control systems. While SEUs are seemingly random and difficult to predict, we correlate their occurrences to space weather phenomena, and specifically show correlations between SEUs and solar proton events (SPEs). SPEs are highly energetic protons that originate from solar coronal mass ejections (CMEs). It is thought that when these particles impact geostationary (GEO) satellites they can cause SEUs as well as solar array degradation. We calculate the associated statistical correlations that each SEU occurs within one day, one week, two weeks, and one month of 10 MeV SPEs between 10 - 10,000 particle flux units (pfu). However, we find that SPEs are most prevalent at solar maximum and that the SEUs on Inmarsat's satellites occur out of phase with the solar maximum. Ultimately, this suggests that SPEs are not the primary cause of the Inmarsat SEUs. A better understanding of the causal relationship between SPEs and SEUs will help the satellite communications industry develop component and operational space weather mitigation techniques as well as help the space weather community to refine radiation models.

Impact of NBTI Aging on the Single-Event Upset of SRAM Cells

CERN Document Server

Bagatin, M; Gerardin, Simone; Paccagnella, Alessandro; Bagatin, Marta

2010-01-01

We analyzed the impact of negative bias temperature instability (NBTI) on the single-event upset rate of SRAM cells through experiments and SPICE simulations. We performed critical charge simulations introducing different degradation patterns in the cells, in three technology nodes, from 180 to 90 nm. The simulations results were checked with alpha-particle and heavy-ion irradiations on a 130-nm technology. Both simulations and experimental results show that NBTI degradation does not significantly affect the single-event upset SRAM cell rate as long as the parametric drift induced by aging is within 10\\%.

Influence of edge effects on single event upset susceptibility of SOI SRAMs

International Nuclear Information System (INIS)

Gu, Song; Liu, Jie; Zhao, Fazhan; Zhang, Zhangang; Bi, Jinshun; Geng, Chao; Hou, Mingdong; Liu, Gang; Liu, Tianqi; Xi, Kai

2015-01-01

An experimental investigation of the single event upset (SEU) susceptibility for heavy ions at tilted incidence was performed. The differences of SEU cross-sections between tilted incidence and normal incidence at equivalent effective linear energy transfer were 21% and 57% for the silicon-on-insulator (SOI) static random access memories (SRAMs) of 0.5 μm and 0.18 μm feature size, respectively. The difference of SEU cross-section raised dramatically with increasing tilt angle for SOI SRAM of deep-submicron technology. The result of CRÈME-MC simulation for tilted irradiation of the sensitive volume indicates that the energy deposition spectrum has a substantial tail extending into the low energy region. The experimental results show that the influence of edge effects on SEU susceptibility cannot be ignored in particular with device scaling down

Measuring the upset of CMOS and TTL due to HPM-signals

Directory of Open Access Journals (Sweden)

N. Esser

2004-01-01

Full Text Available To measure the performance of electronic components when stressed by High Power Microwave signals a setup was designed and tested which allows a well-defined voltage signal to enter the component during normal operation, and to discriminate its effect on the component. The microwave signal is fed to the outside conductor of a coaxial cable and couples into the inner signal line connected to the device under test (DUT. The disturbing HF-signal is transferred almost independent from frequency to maintain the pulse shape in the time domain. The configuration designed to perform a TEM-coupling within a 50 Ohm system prevents the secondary system from feeding back to the primary system and, due to the geometrical parameters chosen, the coupling efficiency is as high as 50–90%. Linear dimensions and terminations applied allow for pulses up to a width of 12ns and up to a voltage level of 4–5 kV on the outside conductor. These pulse parameters proved to be sufficient to upset the DUTs tested so far. In more than 400 measurements a rectangular pulse of increasing voltage level was applied to different types of CMOS and TTL until the individual DUT was damaged. As well the pulse width (3, 6 or 12 ns and its polarity were varied in single-shot or repetitive-shot experiments (500 shots per voltage at a repetition rate of 3 Hz. The state of the DUT was continuously monitored by measuring both the current of the DUT circuit and that of the oscillator providing the operating signal for the DUT. The results show a very good reproducibility within a set of identical samples, remarkable differences between manufacturers and lower thresholds for repetitive testing, which indicates a memory effect of the DUT to exist for voltage levels significantly below the single-shot threshold.

Operational validation - current status and opportunities for improvement

International Nuclear Information System (INIS)

Davey, E.

2002-01-01

The design of nuclear plant systems and operational practices is based on the application of multiple defenses to minimize the risk of occurrence of safety and production challenges and upsets. With such an approach, the effectiveness of individual or combinations of design and operational features in preventing upset challenges should be known. A longstanding industry concern is the adverse impact errors in human performance can have on plant safety and production. To minimize the risk of error occurrence, designers and operations staff routinely employ multiple design and operational defenses. However, the effectiveness of individual or combinations of defensive features in minimizing error occurrence are generally only known in a qualitative sense. More importantly, the margins to error or upset occurrence provided by combinations of design or operational features are generally not characterized during design or operational validation. This paper provides some observations and comments on current validation practice as it relates to operational human performance concerns. The paper also discusses opportunities for future improvement in validation practice in terms of the resilience of validation results to operating changes and characterization of margins to safety or production challenge. (author)

Test results and operational characteristics of prototype SSCL half cell

International Nuclear Information System (INIS)

McInturff, A.D.; Burgett, W.; Carter, H.

1994-01-01

The SSCL Accelerator System's String Test (ASST) has had several cool down, subsequent operational test series, and warm up cycles. The first cycle of these was rather limited in scope as mandated by Congress. The subsequent tests have been performed to obtain more complete information about parameters of, or operating experience with, the ensemble of magnets and spools when operating serially as in accelerator operations. The tests and procedures performed to date have emphasized cryogenic, mechanical, and electrical operations. These have included running, as well as upset conditions, i.e., superconducting to normal transition of the string (quench). This paper represents a summary of the operational test results and characteristics seen to date. A limited discussion will be included as to their implications with respect to a successful accelerator operation

Test CMOS/SOS RAM for transient radiation upset comparative research and failure analysis

International Nuclear Information System (INIS)

Nikiforov, A.Y.; Poljakov, I.V.

1995-01-01

The test Complementary Metal-Oxide-Semiconductor/Silicon-on-Sapphire Random Access Memory (CMOS/SOS RAM) with eight types of memory cells was designed and tested at high dose rates with a flash X-ray machine and laser simulator. The memory cell (MC) design with additional transistors and RC-chain was found to be upset free up to 2 x 10 12 rad(Si)/s. An inversion effect was discovered in which almost 100% logic upset was observed in poorly protected memory cell arrays at very high dose rates

Are Sexual and Emotional Infidelity Equally Upsetting to Men and Women? Making Sense of Forced-Choice Responses

Directory of Open Access Journals (Sweden)

David A. Lishner

2008-10-01

Full Text Available Forced-choice measures that assess reactions to imagined sexual and emotional infidelity are ubiquitous in studies testing the Jealousy as a Specific Innate Module (JSIM model. One potential problem with such measures is that they fail to identify respondents who find both forms of infidelity equally upsetting. To examine this issue, an experiment was conducted in which two groups of participants imagined a romantic infidelity after which participants in the first group used a traditional forced-choice measure to indicate whether they found sexual or emotional infidelity more upsetting. Participants in the second group instead used a modified forced-choice measure that allowed them also to indicate whether they found both forms of infidelity equally upsetting. Consistent with previous research, those given the traditional forced-choice measure tended to respond in a manner that supported the JSIM model. However, the majority of participants given the modified measure indicated that both forms of infidelity were equally upsetting.

Solid-state resistance upset welding: A process with unique advantages for advanced materials

International Nuclear Information System (INIS)

Kanne, W.R. Jr.

1993-01-01

Solid-state resistance upset welding is suitable for joining many alloys that are difficult to weld using fusion processes. Since no melting takes place, the weld metal retains many of the characteristics of the base metal. Resulting welds have a hot worked structure, and thereby have higher strength than fusion welds in the same mate. Since the material being joined is not melted, compositional gradients are not introduced, second phase materials are minimally disrupted, and minor alloying elements, do not affect weldability. Solid-state upset welding has been adapted for fabrication of structures considered very large compared to typical resistance welding applications. The process has been used for closure of capsules, small vessels, and large containers. Welding emphasis has been on 304L stainless steel, the material for current applications. Other materials have, however, received enough attention to have demonstrated capability for joining alloys that are not readily weldable using fusion welding methods. A variety of other stainless steels (including A-286), superalloys (including TD nickel), refractory metals (including tungsten), and aluminum alloys (including 2024) have been successfully upset welded

Upset Prevention and Recovery for Unimpaired and Impaired Aircraft, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The objective of the project is the development of an on-board envelope estimation, protection and upset recovery tool to address loss of control incidents in...

Position sensitive regions in a generic radiation sensor based on single event upsets in dynamic RAMs

International Nuclear Information System (INIS)

Darambara, D.G.; Spyrou, N.M.

1997-01-01

Modern integrated circuits are highly complex systems and, as such, are susceptible to occasional failures. Semiconductor memory devices, particularly dynamic random access memories (dRAMs), are subject to random, transient single event upsets (SEUs) created by energetic ionizing radiation. These radiation-induced soft failures in the stored data of silicon based memory chips provide the foundation for a new, highly efficient, low cost generic radiation sensor. The susceptibility and the detection efficiency of a given dRAM device to SEUs is a complicated function of the circuit design and geometry, the operating conditions and the physics of the charge collection mechanisms involved. Typically, soft error rates measure the cumulative response of all sensitive regions of the memory by broad area chip exposure in ionizing radiation environments. However, this study shows that many regions of a dynamic memory are competing charge collection centres having different upset thresholds. The contribution to soft fails from discrete regions or individual circuit elements of the memory device is unambiguously separated. Hence the use of the dRAM as a position sensitive radiation detector, with high spatial resolution, is assessed and demonstrated. (orig.)

A novel back-up control structure to manage nonroutine steam upsets in industrial methanol distillation columns

DEFF Research Database (Denmark)

Udugama, Isuru A.; Zander, Cornina; Mansouri, Seyed Soheil

2017-01-01

Industrial methanol production plants have extensive heat integration to achieve energy efficient operations where steam generated from these heat integration operations are used to provide reboiler duty for methanol distillation columns that purify crude methanol produced into industrial AA grade...... supervisory layer to control the column during these non-routine process upsets. These control schemes were tested against realistic reboiler duty disturbances that can occur in an industrial process. The tests revealed that both the MPC and supervisory systems control structures are able to regulate...... the process, even during sudden drops in reboiler duty. However, the cost of implementation and the relative simplicity will likely favour the implementation of the supervisory control structure in an industrial environment....

Single event upset studies on the CMS tracker APV25 readout chip

International Nuclear Information System (INIS)

Noah, E.; Bauer, T.; Bisello, D.; Faccio, F.; Friedl, M.; Fulcher, J.R.; Hall, G.; Huhtinen, M.; Kaminsky, A.; Pernicka, M.; Raymond, M.; Wyss, J.

2002-01-01

The microstrip tracker for the CMS experiment at the CERN Large Hadron Collider will be read out using APV25 chips. During high luminosity running the tracker will be exposed to particle fluxes up to 10 7 cm -2 s -1 , which raises concerns that the APV25 could occasionally suffer Single Event Upsets (SEUs). The effect of SEU on the APV25 has been studied to investigate implications for CMS detector operation and from the viewpoint of detailed circuit operation, to improve the understanding of its origin and what factors affect its magnitude. Simulations were performed to reconstruct the effects created by highly ionising particles striking sensitive parts of the circuits, along with consideration of the underlying mechanisms of charge deposition, collection and the consequences. A model to predict the behaviour of the memory circuits in the APV25 has been developed and data collected from dedicated experiments using both heavy ions and hadrons have been shown to support it

The educational inclusion of the students with upsets of the oral communication

Directory of Open Access Journals (Sweden)

Merling Murguia Moré

2015-09-01

Full Text Available The educational inclusion imposes challenges to the National System of Education, to optimize the attention to the students with upsets of the oral communication. Is the objective of the article to share the design of an investigation that assists to the scientific problem how to contribute to the improvement of the educational inclusion of the students with upsets of the oral communication? The employment of the investigation-action-participativa it drives to the execution of the objective related with the construction of a pedagogic model for the improvement of this process. The results of the investigation will constitute a necessary contribution to the educational inclusion in the National System of Education

Investigation and control of factors influencing resistance upset butt welding.

NARCIS (Netherlands)

Kerstens, N.F.H.

2010-01-01

The purpose of this work is to investigate the factors influencing the resistance upset butt welding process to obtain an understanding of the metal behaviour and welding process characteristics, so that new automotive steels can be welded with reduced development time and fewer failures in

Perturbations of normally solvable nonlinear operators, I

Directory of Open Access Journals (Sweden)

William O. Ray

1985-01-01

Full Text Available Let X and Y be Banach spaces and let ℱ and be Gateaux differentiable mappings from X to Y In this note we study when the operator ℱ+ is surjective for sufficiently small perturbations of a surjective operator ℱ The methods extend previous results in the area of normal solvability for nonlinear operators.

Designing for a safe response to operational and severe accident initiators in the Integral Fast Reactor

International Nuclear Information System (INIS)

Vilim, R.B.

1994-01-01

A method is described for optimizing the plant control strategy for a liquid metal reactor with respect to safety margins sustained in unprotected upset events. The optimization is performed subject to the normal requirements for reactor startup, load change and compensation for reactivity changes over the cycle. The method provides a formal approach to the process of exploiting the innate self-regulating property of a metal fueled reactor to make it less dependent on operator action and less vulnerable to automatic control system fault and/or operator error

upSET, the Drosophila homologue of SET3, Is Required for Viability and the Proper Balance of Active and Repressive Chromatin Marks

Directory of Open Access Journals (Sweden)

Kyle A. McElroy

2017-02-01

Full Text Available Chromatin plays a critical role in faithful implementation of gene expression programs. Different post-translational modifications (PTMs of histone proteins reflect the underlying state of gene activity, and many chromatin proteins write, erase, bind, or are repelled by, these histone marks. One such protein is UpSET, the Drosophila homolog of yeast Set3 and mammalian KMT2E (MLL5. Here, we show that UpSET is necessary for the proper balance between active and repressed states. Using CRISPR/Cas-9 editing, we generated S2 cells that are mutant for upSET. We found that loss of UpSET is tolerated in S2 cells, but that heterochromatin is misregulated, as evidenced by a strong decrease in H3K9me2 levels assessed by bulk histone PTM quantification. To test whether this finding was consistent in the whole organism, we deleted the upSET coding sequence using CRISPR/Cas-9, which we found to be lethal in both sexes in flies. We were able to rescue this lethality using a tagged upSET transgene, and found that UpSET protein localizes to transcriptional start sites (TSS of active genes throughout the genome. Misregulated heterochromatin is apparent by suppressed position effect variegation of the wm4 allele in heterozygous upSET-deleted flies. Using nascent-RNA sequencing in the upSET-mutant S2 lines, we show that this result applies to heterochromatin genes generally. Our findings support a critical role for UpSET in maintaining heterochromatin, perhaps by delimiting the active chromatin environment.

Direct Observation of Asperity Deformation of Specimen with Random Rough Surface in Upsetting Process

DEFF Research Database (Denmark)

Azushima, A.; Kuba, S.; Tani, S.

2004-01-01

The trapping behavior of liquid lubricant and contact behavior of asperities at the workpiece-tool interface during upsetting and indentation are observed directly using a compression subpress which consists of a transparent die made of sapphire, a microscope with a CCD camera and a video system....... The experiments are carried out without lubricant and with lubricant. Specimens used are commercially pure A1100 Aluminum with a random rough surface. From this observation, the change in the fraction of real contact area is measured by an image processor. The real contact area ratios in upsetting experiment...

Single-event phenomena on recent semiconductor devices. Charge-type multiple-bit upsets in high integrated memories

International Nuclear Information System (INIS)

Makihara, Akiko; Shindou, Hiroyuki; Nemoto, Norio; Kuboyama, Satoshi; Matsuda, Sumio; Ohshima, Takeshi; Hirao, Toshio; Itoh, Hisayoshi

2001-01-01

High integrated memories are used in solid state data recorder (SSDR) of the satellite for accumulating observation data. Single event upset phenomena which turn over an accumulated data in the memory cells are caused by heavy ion incidence. Studies on single-bit upset and multiple-bit upset phenomena in the high integrated memory cells are in progress recently. 16 Mbit DRAM (Dynamic Random Access Memories) and 64 Mbit DRAM are irradiated by heavy ion species, such as iodine, bromine and nickel, in comparison with the irradiation damage in the cosmic environment. Data written on the memory devices are read out after the irradiation. The memory cells in three kinds of states, all of charged state, all of discharged state, and an alternative state of charge and discharge, are irradiated for sorting out error modes caused by heavy ion incidence. The soft error in a single memory cells is known as a turn over from charged state to discharged state. Electrons in electron-hole pair generated by heavy ion incidence are captured in a diffusion region between capacitor electrodes of semiconductor. The charged states in the capacitor electrodes before the irradiation are neutralized and changed to the discharged states. According to high integration of the memories, many of the cells are affected by a single ion incidence. The multiple-bit upsets, however, are generated in the memory cells of discharged state before the irradiation, also. The charge-type multiple-bit upsets is considered as that error data are written on the DRAM during refresh cycle of a sense-up circuit and a pre-charge circuit which control the DRAM. (M. Suetake)

High electrical resistivity Nd-Fe-B die-upset magnet doped with eutectic DyF3–LiF salt mixture

Directory of Open Access Journals (Sweden)

K. M. Kim

2017-05-01

Full Text Available Nd-Fe-B-type die-upset magnet with high electrical resistivity was prepared by doping of eutectic DyF3–LiF salt mixture. Mixture of melt-spun Nd-Fe-B flakes (MQU-F: Nd13.6Fe73.6Co6.6Ga0.6B5.6 and eutectic binary (DyF3–LiF salt (25 mol% DyF3 – 75 mol% LiF was hot-pressed and then die-upset. By adding the eutectic salt mixture (> 4 wt%, electrical resistivity of the die-upset magnet was enhanced to over 400 μΩ.cm compared to 190 μΩ.cm of the un-doped magnet. Remarkable enhancement of the electrical resistivity was attributed to homogeneous and continuous coverage of the interface between flakes by the easily melted eutectic salt dielectric mixture. It was revealed that active substitution of the Nd atoms in neighboring flakes by the Dy atoms from the added (DyF3–LiF salt mixture had occurred during such a quick thermal processing of hot-pressing and die-upsetting. This Dy substitution led to coercivity enhancement in the die-upset magnet doped with the eutectic (DyF3–LiF salt mixture. Coercivity and remanence of the die-upset magnet doped with (DyF3–LiF salt mixture was as good as those of the DyF3-doped magnet.

The role of the control room operator

International Nuclear Information System (INIS)

Williams, M.C.

A control room operator at an Ontario Hydro nuclear power plant operates a reactor-turbine unit according to approved procedures within imposed constraints to meet the objectives of the organization. A number of operating and administrative tasks make up this role. Control room operators spend approximately six percent of their time physically operating equipment exclusive of upset conditions, and another one percent operating in upset conditions. Testing occupies five percent of an operator's time. Operators must be trained to recognize the entire spectrum of inputs available to them and use them all effectively. Any change in system or unit state is always made according to an approved procedure. Extensive training is required; operators must be taught and pracised in what to do, and must know the reasons behind their actions. They are expected to memorize emergency procedures, to know when to consult operating procedures, and to have sufficient understanding and practice to perform these procedures reliably

Crying without a cause and being easily upset in two-year-olds: heritability and predictive power of behavioral problems.

Science.gov (United States)

Groen-Blokhuis, Maria M; Middeldorp, Christel M; M van Beijsterveldt, Catharina E; Boomsma, Dorret I

2011-10-01

In order to estimate the influence of genetic and environmental factors on 'crying without a cause' and 'being easily upset' in 2-year-old children, a large twin study was carried out. Prospective data were available for ~18,000 2-year-old twin pairs from the Netherlands Twin Register. A bivariate genetic analysis was performed using structural equation modeling in the Mx software package. The influence of maternal personality characteristics and demographic and lifestyle factors was tested to identify specific risk factors that may underlie the shared environment of twins. Furthermore, it was tested whether crying without a cause and being easily upset were predictive of later internalizing, externalizing and attention problems. Crying without a cause yielded a heritability estimate of 60% in boys and girls. For easily upset, the heritability was estimated at 43% in boys and 31% in girls. The variance explained by shared environment varied between 35% and 63%. The correlation between crying without a cause and easily upset (r = .36) was explained both by genetic and shared environmental factors. Birth cohort, gestational age, socioeconomic status, parental age, parental smoking behavior and alcohol use during pregnancy did not explain the shared environmental component. Neuroticism of the mother explained a small proportion of the additive genetic, but not of the shared environmental effects for easily upset. Crying without a cause and being easily upset at age 2 were predictive of internalizing, externalizing and attention problems at age 7, with effect sizes of .28-.42. A large influence of shared environmental factors on crying without a cause and easily upset was detected. Although these effects could be specific to these items, we could not explain them by personality characteristics of the mother or by demographic and lifestyle factors, and we recognize that these effects may reflect other maternal characteristics. A substantial influence of genetic factors

Development and Flight Testing of an Automated Upset Recovery System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Loss of control (LOC) due to upset is one of the main causes of accidents in manned aircraft and is already emerging as a significant causal factor in unmanned...

The spectral theorem for quaternionic unbounded normal operators based on the S-spectrum

Energy Technology Data Exchange (ETDEWEB)

Alpay, Daniel, E-mail: dany@math.bgu.ac.il; Kimsey, David P., E-mail: dpkimsey@gmail.com [Department of Mathematics, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Colombo, Fabrizio, E-mail: fabrizio.colombo@polimi.it [Politecnico di Milano, Dipartimento di Matematica, Via E. Bonardi, 9, 20133 Milano (Italy)

2016-02-15

In this paper we prove the spectral theorem for quaternionic unbounded normal operators using the notion of S-spectrum. The proof technique consists of first establishing a spectral theorem for quaternionic bounded normal operators and then using a transformation which maps a quaternionic unbounded normal operator to a quaternionic bounded normal operator. With this paper we complete the foundation of spectral analysis of quaternionic operators. The S-spectrum has been introduced to define the quaternionic functional calculus but it turns out to be the correct object also for the spectral theorem for quaternionic normal operators. The lack of a suitable notion of spectrum was a major obstruction to fully understand the spectral theorem for quaternionic normal operators. A prime motivation for studying the spectral theorem for quaternionic unbounded normal operators is given by the subclass of unbounded anti-self adjoint quaternionic operators which play a crucial role in the quaternionic quantum mechanics.

Final results of the supra project : Improved Simulation of Upset Recovery

NARCIS (Netherlands)

Fucke, L.; Groen, E.; Goman, M.; Abramov, N.; Wentink, M.; Nooij, S.; Zaichik, L.E.; Khrabrov, A.

2012-01-01

The objective of the European research project SUPRA (Simulation of Upset Recovery in Aviation) is to develop technologies that eventually contribute to a reduction of risk of Loss of control - in flight (LOC-I) accidents, today's major cause of fatal accidents in commercial aviation. To this end

CMOS/SOS RAM transient radiation upset and ''inversion'' effect investigation

International Nuclear Information System (INIS)

Nikiforov, A.Y.; Poljakov, I.V.

1996-01-01

The Complementary Metal-Oxide-Semiconductor/Silicon-on-Sapphire Random Access Memory (CMOS/SOS RAM) transient upset and inversion effect were investigated with pulsed laser, pulsed voltage generator and low-intensity light simulators. It was found that the inversion of information occurs due to memory cell photocurrents simultaneously with the power supply voltage drop transfer to memory cells outputs

Dynamics Modeling and Simulation of Large Transport Airplanes in Upset Conditions

Science.gov (United States)

Foster, John V.; Cunningham, Kevin; Fremaux, Charles M.; Shah, Gautam H.; Stewart, Eric C.; Rivers, Robert A.; Wilborn, James E.; Gato, William

2005-01-01

As part of NASA's Aviation Safety and Security Program, research has been in progress to develop aerodynamic modeling methods for simulations that accurately predict the flight dynamics characteristics of large transport airplanes in upset conditions. The motivation for this research stems from the recognition that simulation is a vital tool for addressing loss-of-control accidents, including applications to pilot training, accident reconstruction, and advanced control system analysis. The ultimate goal of this effort is to contribute to the reduction of the fatal accident rate due to loss-of-control. Research activities have involved accident analyses, wind tunnel testing, and piloted simulation. Results have shown that significant improvements in simulation fidelity for upset conditions, compared to current training simulations, can be achieved using state-of-the-art wind tunnel testing and aerodynamic modeling methods. This paper provides a summary of research completed to date and includes discussion on key technical results, lessons learned, and future research needs.

Ductile failure in upsetting of a rapid-solidification-processed aluminium alloy

NARCIS (Netherlands)

Habraken, F.A.C.M.; Dautzenberg, J.H.

1993-01-01

Cold upset-tests have been performed on a Rapid Solidification Processed (RSP) aluminium-alloy, produced by the ‘melt-spun ribbons’-process out of 70% car-scrap and 30% primary scrap. The ribbons are hot extruded, resulting in 29 mm diameter bar. Its properties regarding plastic flow and fracture

nth roots with Hilbert-Schmidt defect operator of normal contractions

International Nuclear Information System (INIS)

Duggal, B.P.

1992-08-01

Let T be a normal contraction (on a complex separable Hilbert space H into itself) with an nth root A such that the defect operator D A =(1-A*A) 1/2 is of the Hilbert-Schmidt class C 2 . Then either A is normal or A is similar to a normal contraction. In the case in which T is hyponormal, A n =T and D A is an element of C 2 , A is a ''coupling'' of a contraction similar to a normal contraction and a contraction which is the quasi-affine transform of a unilateral shift. These results are applied to prove a (Putnam-Fuglede type) commutatively theorem for operator valued roots of commutative analytic functions and hyponormal contractions T which have an nth root with Hilbert-Schmidt defect operator. 23 refs

Direct observation of asperity deformation of specimens with random rough surfaces in upsetting and indentation processes

DEFF Research Database (Denmark)

Azushima, A.; Kuba, S.; Tani, S.

2006-01-01

The trapping behavior of liquid lubricant and contact behavior of asperities at the workpiece-tool interface during upsetting and indentation are observed directly using a compression subpress which consists of a transparent die made of sapphire, a microscope with a CCD camera and a video system....... The experiments are carried out without lubricant and with lubricant. Specimens used are commercially pure A1100 aluminum with a random rough surface. From these observations, the change in the fraction of real contact area is measured by an image processor. The real contact area ratios in upsetting experiments...

Some Normal Intuitionistic Fuzzy Heronian Mean Operators Using Hamacher Operation and Their Application

Directory of Open Access Journals (Sweden)

Guofang Zhang

2018-06-01

Full Text Available Hamacher operation is a generalization of the algebraic and Einstein operation and expresses a family of binary operation in the unit interval [0,1]. Heronian mean can deal with correlations of different criteria or input arguments and does not bring out repeated calculation. The normal intuitionistic fuzzy numbers (NIFNs can depict normal distribution information in practical decision making. A decision-making problem was researched under the NIFN environment in this study, and a new multi-criteria group decision-making (MCGDM approach is herein introduced on the basis of Hamacher operation. Firstly, according to Hamacher operation, some operational laws of NIFNs are presented. Secondly, it is noted that Heronian mean not only takes into account mutuality between the attribute values once, but also considers the correlation between input argument and itself. Therefore, in order to aggregate NIFN information, we developed some operators and studied their properties. These operators include Hamacher Heronian mean (NIFHHM, Hamacher weighted Heronian mean (NIFHWHM, Hamacher geometric Heronian mean (NIFHGHM, and Hamacher weighted geometric Heronian mean (NIFHWGHM. Furthermore, we applied the proposed operators to the MCGDM problem and developed a new MCGDM approach. The characteristics of this new approach are that: (1 it is suitable for making a decision under the NIFN environment and it is more reasonable for aggregating the normal distribution data; (2 it utilizes Hamacher operation to provide an effective and powerful MCGDM algorithm and to make more reliable and more flexible decisions under the NIFN circumstance; (3 it uses the Heronian mean operator to deal with interrelations between the attributes or input arguments, and it does not bring about repeated calculation. Therefore, the proposed method can describe the interaction of the different criteria or input arguments and offer some reasonable and reliable MCGDM aggregation operators

Limiting Normal Operator in Quasiconvex Analysis

Czech Academy of Sciences Publication Activity Database

Aussel, D.; Pištěk, Miroslav

2015-01-01

Roč. 23, č. 4 (2015), s. 669-685 ISSN 1877-0533 R&D Projects: GA ČR GA15-00735S Institutional support: RVO:67985556 Keywords : Quasiconvex function * Sublevel set * Normal operator Subject RIV: BA - General Mathematics Impact factor: 0.973, year: 2015 http://library.utia.cas.cz/separaty/2015/MTR/pistek-0453552.pdf

A Computuerized Operator Support System Prototype

Energy Technology Data Exchange (ETDEWEB)

Thomas, Ken [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boring, Ronald [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lew, Roger [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ulrich, Tom [Idaho National Lab. (INL), Idaho Falls, ID (United States); Villim, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2013-11-01

A report was published by the Idaho National Laboratory in September of 2012, entitled Design to Achieve Fault Tolerance and Resilience, which described the benefits of automating operator actions for transients. The report identified situations in which providing additional automation in lieu of operator actions would be advantageous. It recognized that managing certain plant upsets is sometimes limited by the operator’s ability to quickly diagnose the fault and to take the needed actions in the time available. Undoubtedly, technology is underutilized in the nuclear power industry for operator assistance during plant faults and operating transients. In contrast, other industry sectors have amply demonstrated that various forms of operator advisory systems can enhance operator performance while maintaining the role and responsibility of the operator as the independent and ultimate decision-maker. A computerized operator support system (COSS) is proposed for use in nuclear power plants to assist control room operators in addressing time-critical plant upsets. A COSS is a collection of technologies to assist operators in monitoring overall plant performance and making timely, informed decisions on appropriate control actions for the projected plant condition. The COSS does not supplant the role of the operator, but rather provides rapid assessments, computations, and recommendations to reduce workload and augment operator judgment and decision-making during fast-moving, complex events. This project proposes a general model for a control room COSS that addresses a sequence of general tasks required to manage any plant upset: detection, validation, diagnosis, recommendation, monitoring, and recovery. The model serves as a framework for assembling a set of technologies that can be interrelated to assist with each of these tasks. A prototype COSS has been developed in order to demonstrate the concept and provide a test bed for further research. The prototype is based

A Computuerized Operator Support System Prototype

Energy Technology Data Exchange (ETDEWEB)

Thomas, Ken [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boring, Ronald [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lew, Roger [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ulrich, Tom [Idaho National Lab. (INL), Idaho Falls, ID (United States); Villim, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2013-08-01

A report was published by the Idaho National Laboratory in September of 2012, entitled Design to Achieve Fault Tolerance and Resilience, which described the benefits of automating operator actions for transients. The report identified situations in which providing additional automation in lieu of operator actions would be advantageous. It recognized that managing certain plant upsets is sometimes limited by the operator’s ability to quickly diagnose the fault and to take the needed actions in the time available. Undoubtedly, technology is underutilized in the nuclear power industry for operator assistance during plant faults and operating transients. In contrast, other industry sectors have amply demonstrated that various forms of operator advisory systems can enhance operator performance while maintaining the role and responsibility of the operator as the independent and ultimate decision-maker. A computerized operator support system (COSS) is proposed for use in nuclear power plants to assist control room operators in addressing time-critical plant upsets. A COSS is a collection of technologies to assist operators in monitoring overall plant performance and making timely, informed decisions on appropriate control actions for the projected plant condition. The COSS does not supplant the role of the operator, but rather provides rapid assessments, computations, and recommendations to reduce workload and augment operator judgment and decision-making during fast-moving, complex events. This project proposes a general model for a control room COSS that addresses a sequence of general tasks required to manage any plant upset: detection, validation, diagnosis, recommendation, monitoring, and recovery. The model serves as a framework for assembling a set of technologies that can be interrelated to assist with each of these tasks. A prototype COSS has been developed in order to demonstrate the concept and provide a test bed for further research. The prototype is based

Development of advanced automatic operation system for nuclear ship. 1. Perfect automatic normal operation

International Nuclear Information System (INIS)

Nakazawa, Toshio; Yabuuti, Noriaki; Takahashi, Hiroki; Shimazaki, Junya

1999-02-01

Development of operation support system such as automatic operating system and anomaly diagnosis systems of nuclear reactor is very important in practical nuclear ship because of a limited number of operators and severe conditions in which receiving support from others in a case of accident is very difficult. The goal of development of the operation support systems is to realize the perfect automatic control system in a series of normal operation from the reactor start-up to the shutdown. The automatic control system for the normal operation has been developed based on operating experiences of the first Japanese nuclear ship 'Mutsu'. Automation technique was verified by 'Mutsu' plant data at manual operation. Fully automatic control of start-up and shutdown operations was achieved by setting the desired value of operation and the limiting value of parameter fluctuation, and by making the operation program of the principal equipment such as the main coolant pump and the heaters. This report presents the automatic operation system developed for the start-up and the shutdown of reactor and the verification of the system using the Nuclear Ship Engineering Simulator System. (author)

Small Aircraft Transportation System, Higher Volume Operations Concept: Normal Operations

Science.gov (United States)

Abbott, Terence S.; Jones, Kenneth M.; Consiglio, Maria C.; Williams, Daniel M.; Adams, Catherine A.

2004-01-01

This document defines the Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) concept for normal conditions. In this concept, a block of airspace would be established around designated non-towered, non-radar airports during periods of poor weather. Within this new airspace, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Using onboard equipment and procedures, they would then approach and land at the airport. Departures would be handled in a similar fashion. The details for this operational concept are provided in this document.

A Novel Application of Machine Learning Methods to Model Microcontroller Upset Due to Intentional Electromagnetic Interference

Science.gov (United States)

Bilalic, Rusmir

A novel application of support vector machines (SVMs), artificial neural networks (ANNs), and Gaussian processes (GPs) for machine learning (GPML) to model microcontroller unit (MCU) upset due to intentional electromagnetic interference (IEMI) is presented. In this approach, an MCU performs a counting operation (0-7) while electromagnetic interference in the form of a radio frequency (RF) pulse is direct-injected into the MCU clock line. Injection times with respect to the clock signal are the clock low, clock rising edge, clock high, and the clock falling edge periods in the clock window during which the MCU is performing initialization and executing the counting procedure. The intent is to cause disruption in the counting operation and model the probability of effect (PoE) using machine learning tools. Five experiments were executed as part of this research, each of which contained a set of 38,300 training points and 38,300 test points, for a total of 383,000 total points with the following experiment variables: injection times with respect to the clock signal, injected RF power, injected RF pulse width, and injected RF frequency. For the 191,500 training points, the average training error was 12.47%, while for the 191,500 test points the average test error was 14.85%, meaning that on average, the machine was able to predict MCU upset with an 85.15% accuracy. Leaving out the results for the worst-performing model (SVM with a linear kernel), the test prediction accuracy for the remaining machines is almost 89%. All three machine learning methods (ANNs, SVMs, and GPML) showed excellent and consistent results in their ability to model and predict the PoE on an MCU due to IEMI. The GP approach performed best during training with a 7.43% average training error, while the ANN technique was most accurate during the test with a 10.80% error.

Crate counter for normal operating loss

International Nuclear Information System (INIS)

Harlan, R.A.

A lithium-loaded zinc sulfide scintillation counter to closely assay plutonium in waste packaged in 1.3 by 1.3 by 2.13m crates was built. In addition to assays for normal operating loss accounting, the counter will allow safeguards verification immediately before shipment of the crates for burial. The counter should detect approximately 10 g of plutonium in 1000 kg of waste

Manual on environmental monitoring in normal operation

International Nuclear Information System (INIS)

1966-01-01

Many establishments handling radioactive materials produce, and to some extent also discharge, radioactive waste as part of their normal operation. The radiation doses to which members of the public may be exposed during such operation must remain below the stipulated level. The purpose of this manual is to provide technical guidance for setting up programmes of routine environmental monitoring in the vicinity of nuclear establishment. The annex gives five examples of routine environmental monitoring programmes currently in use: these have been indexed separately.

Integral type operators from normal weighted Bloch spaces to QT,S spaces

Directory of Open Access Journals (Sweden)

Yongyi GU

2016-08-01

Full Text Available Operator theory is an important research content of the analytic function space theory. The discussion of simultaneous operator and function space is an effective way to study operator and function space. Assuming that  is an analytic self map on the unit disk Δ, and the normal weighted bloch space μ-B is a Banach space on the unit disk Δ, defining a composition operator C∶C(f=f on μ-B for all f∈μ-B, integral type operator JhC and CJh are generalized by integral operator and composition operator. The boundeness and compactness of the integral type operator JhC acting from normal weighted Bloch spaces to QT,S spaces are discussed, as well as the boundeness of the integral type operators CJh acting from normal weighted Bloch spaces to QT,S spaces. The related sufficient and necessary conditions are given.

Environmental dosimetry for normal operations at SRP. Revision 1

International Nuclear Information System (INIS)

Marter, W.L.

1984-01-01

The radiological effect of environmental releases from SRP during normal operations has been assessed annually since 1972 with a dosimetry model developed by SRL in 1971 to 1972, as implemented in the MREM code for atmospheric releases and RIVDOSE code for liquid releases. Starting in 1978, SRL started using environmental models and dose commitment factors developed by Nuclear Regulatory Commission (NRC) for all other environmental dose calculations. The NRC models are more flexible than the older SRL models, use more up-to-date methodologies, cover more exposure pathways, and permit more detailed analysis of effects of normal operations. It is recommended that the NRC models, as implemented in the computer codes X0QD0Q and GASPAR for atmospheric releases and LADTAP for liquid releases, and NRC dose commitment factors be used as the standard method at SRP for assessing offsite dose from normal operations in Health Protection Department annual environmental monitoring reports, and in National Environmental Policy Act documents and Safety Analysis Reports for SRP facilities. 23 references, 3 figures, 9 tables

Development of symptoms-oriented operating procedures

International Nuclear Information System (INIS)

Colquhoun, R.

1984-01-01

Until recently, the formal treatment of control room procedures for upset conditions in nuclear power plants has been event-oriented. This orientation was not so much a reflection of power plant operating practice as it was a reflection of design-oriented thinking - design-basis events, therefore event-oriented procedures. Event orientation is not common in other professions. In the medical profession, for example, the stabilization of vital functions through a symptoms-oriented approach has priority over diagnosis and prognosis. The American nuclear power industry has initiated programs for the development and application of a symptoms-oriented approach for handling upset conditions. Canadian programs have independently paralleled the US programs. This article describes the rationale and current applications of the Canadian programs and identifies the relevance of a generic symptoms-based emergency procedure to current operating practices

The development of symptoms-oriented operating procedures

International Nuclear Information System (INIS)

Colquhoun, R.

1983-04-01

Until recently the formal treatment of control room procedures for nuclear power plant upset conditions has been event-oriented. The demise of Three Mile Island, Unit 2, caused the American industry to recognize the pitfalls inherent in relying totally on event-oriented procedures, and led to the initiation of a program for the development of a symptoms-oriented approach for handling upset conditions. The U.S. program has been independently paralleled by a Canadian program. This paper describes the development of the Canadian symptoms-oriented philosophy and identifies the relevance of a generic symptoms based emergency procedure to current operating practices

Investigation and control of factors influencing resistance upset butt welding.

OpenAIRE

Kerstens, N.F.H.

2010-01-01

The purpose of this work is to investigate the factors influencing the resistance upset butt welding process to obtain an understanding of the metal behaviour and welding process characteristics, so that new automotive steels can be welded with reduced development time and fewer failures in production. In principle the welding process is rather simple, the materials to be joined are clamped between two electrodes and pressed together. Because there is an interface present with a higher resist...

Acquisition and classification of static single-event upset cross section for SRAM-based FPGAs

International Nuclear Information System (INIS)

Yao Zhibin; Fan Ruyu; Guo Hongxia; Wang Zhongming; He Baoping; Zhang Fengqi; Zhang Keying

2011-01-01

In order to evaluate single event upsets (SEUs) in SRAM-based FPGAs and to find the sensitive resource in configuration memory, a heavy ions irradiation experiment was carried out on a Xilinx FPGAs device XCV300PQ240. The experiment was conducted to gain the static SEU cross section and classify the SEUs in configurations memory according to different resource uses. The results demonstrate that the inter-memory of SRAM-based FPGAs is extremely sensitive to heavy-ion-induced SEUs. The LUT and routing resources are the main source of SEUs in the configuration memory, which covers more than 97.46% of the total upsets. The SEU sensitivity of various resources is different. The IOB control bit and LUT elements are more sensitive,and more attention should be paid to the LUT elements in radiation hardening,which account for a quite large proportion of the configuration memory. (authors)

Single Event Upset Energy Dependence In a Buck-Converter Power Supply Design

CERN Document Server

Drake, G; The ATLAS collaboration; Gopalakrishnan, A; Mahadik, S; Mellado, B; Proudfoot, J; Reed, R; Senthilkumaran, A; Stanek, R

2012-01-01

We present a study of Single Event Upsets (SEU) performed on a commercial pulse-width modulator controller chip for switching power supplies. We performed tests to study the probability of an SEU occurring as a function of incident particle (hadron) energy. We discuss the performance of the circuit, and present a solution using external circuitry to effectively eliminate the effect.

Device simulation of charge collection and single-event upset

International Nuclear Information System (INIS)

Dodd, P.E.

1996-01-01

In this paper the author reviews the current status of device simulation of ionizing-radiation-induced charge collection and single-event upset (SEU), with an emphasis on significant results of recent years. The author presents an overview of device-modeling techniques applicable to the SEU problem and the unique challenges this task presents to the device modeler. He examines unloaded simulations of radiation-induced charge collection in simple p/n diodes, SEU in dynamic random access memories (DRAM's), and SEU in static random access memories (SRAM's). The author concludes with a few thoughts on future issues likely to confront the SEU device modeler

Evaluation of the upset risk in CMOS SRAM through full three dimensional simulation

International Nuclear Information System (INIS)

Moreau, Y.; Gasiot, J.; Duzellier, S.

1995-01-01

Upsets caused by incident heavy ion on CMOS static RAM are studied here. Three dimensional device simulations, based on a description of a full epitaxial CMOS inverter, and experimental results are reported for evaluation of single and multiple bit error risk. The particular influences of hit location and incidence angle are examined

PV System Performance Evaluation by Clustering Production Data to Normal and Non-Normal Operation

NARCIS (Netherlands)

Tsafarakis, O.; Sinapis, K.; van Sark, W.G.J.H.M.

2018-01-01

The most common method for assessment of a photovoltaic (PV) system performance is by comparing its energy production to reference data (irradiance or neighboring PV system). Ideally, at normal operation, the compared sets of data tend to show a linear relationship. Deviations from this linearity

Prediction of particle orientation in simple upsetting process of NdFeB magnets

Energy Technology Data Exchange (ETDEWEB)

Chang, Chao-Cheng; Hsiao, Po-Jen [Department of Mold and Die Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Sanmin District, Kaohsiung 80778, Taiwan (China); You, Jr-Shiang; Chen, Yen-Ju; Chang, Can-Xun [Metal Forming Technology Section, Metal Processing R and D Department, Metal Industries Research and Development Centre, 1001 Kaonan Highway, Kaohsiung 81160, Taiwan (China)

2013-12-16

The magnetic properties of NdFeB magnets are strongly affected by crystallographic texture which is highly associated with particle orientation. This study proposed a method for predicting the particle orientation in the simple upsetting process of NdFeB magnets. The method is based on finite element simulation with flow net analysis. The magnets in a cylindrical form were compressed by two flat dies in a chamber filled with argon at 750°C. Three forming speeds were taken into account in order to obtain flow stress curves used in simulations. The micrographs of the cross sections of the deformed magnets show that the particle deformation significantly increases with the compression. The phenomenon was also predicted by the proposed method. Both simulated and experimental results show that the inhomogeneity of the texture of the NdFeB magnets can be increased by the simple upsetting process. The predicted particle orientations were in a good agreement with those examined in the deformed magnets. The proposed method for predicting particle orientations can also be used in other forming processes of NdFeB magnets.

Prediction of particle orientation in simple upsetting process of NdFeB magnets

International Nuclear Information System (INIS)

Chang, Chao-Cheng; Hsiao, Po-Jen; You, Jr-Shiang; Chen, Yen-Ju; Chang, Can-Xun

2013-01-01

The magnetic properties of NdFeB magnets are strongly affected by crystallographic texture which is highly associated with particle orientation. This study proposed a method for predicting the particle orientation in the simple upsetting process of NdFeB magnets. The method is based on finite element simulation with flow net analysis. The magnets in a cylindrical form were compressed by two flat dies in a chamber filled with argon at 750°C. Three forming speeds were taken into account in order to obtain flow stress curves used in simulations. The micrographs of the cross sections of the deformed magnets show that the particle deformation significantly increases with the compression. The phenomenon was also predicted by the proposed method. Both simulated and experimental results show that the inhomogeneity of the texture of the NdFeB magnets can be increased by the simple upsetting process. The predicted particle orientations were in a good agreement with those examined in the deformed magnets. The proposed method for predicting particle orientations can also be used in other forming processes of NdFeB magnets

Comparison of analytical models and experimental results for single-event upset in CMOS SRAMs

International Nuclear Information System (INIS)

Mnich, T.M.; Diehl, S.E.; Shafer, B.D.

1983-01-01

In an effort to design fully radiation-hardened memories for satellite and deep-space applications, a 16K and a 2K CMOS static RAM were modeled for single-particle upset during the design stage. The modeling resulted in the addition of a hardening feedback resistor in the 16K remained tentatively unaltered. Subsequent experiments, using the Lawrence Berkeley Laboratories' 88-inch cyclotron to accelerate krypton and oxygen ions, established an upset threshold for the 2K and the 16K without resistance added, as well as a hardening threshold for the 16K with feedback resistance added. Results for the 16K showed it to be hardenable to the higher level than previously published data for other unhardened 16K RAMs. The data agreed fairly well with the modeling results; however, a close look suggests that modification of the simulation methodology is required to accurately predict the resistance necessary to harden the RAM cell

The AECL operator companion

International Nuclear Information System (INIS)

Lupton, L.R.; Anderson, L.L.; Basso, R.A.J.

1989-11-01

As CANDU plants become more complex, and are operated under tighter constraints and for longer periods between outages, plant operations staff will have to absorb more information to correctly and rapidly respond to upsets. A development program is underway at AECL to use expert systems and interactive media tools to assist operations staff of existing and future CANDU plants. The complete system for plant information access and display, on-line advice and diagnosis, and interactive operating procedures is called the Operator Companion. A prototype, consisting of operator consoles, expert systems and simulation modules in a distributed architecture, is currently being developed to demonstrate the concepts of the Operator Companion

Effect of material parameters on stress wave propagation during fast upsetting

Institute of Scientific and Technical Information of China (English)

WANG Zhong-jin; CHENG Li-dong

2008-01-01

Based'on a dynamic analysis method and an explicit algorithm, a dynamic explicit finite element code was developed for modeling the fast upsetting process of block under drop hammer impact, in which the hammer velocity during the deformation was calculated by energy conservation law according to the operating principle of hammer equipment. The stress wave propagation and its effect on the deformation were analyzed by the stress and strain distributions. Industrial pure lead, oxygen-free high-conductivity (OFHC) copper and 7039 aluminum alloy were chosen to investigate the effect of material parameters on the stress wave propagation. The results show that the stress wave propagates from top to bottom of block, and then reflects back when it reaches the bottom surface. After that, stress wave propagates and reflects repeatedly between the upper surface and bottom surface. The stress wave propagation has a significant effect on the deformation at the initial stage, and then becomes weak at the middle-final stage. When the ratio of elastic modulus or the slope of stress-strain curve to mass density becomes larger, the velocity of stress wave propagation increases, and the influence of stress wave on the deformation becomes small.

Operating conditions of steam generators for LMFBR's

Energy Technology Data Exchange (ETDEWEB)

Ratzel, W

1975-07-01

Operating conditions considered to be appropriate for a LMFBR steam generator are discussed on the example of the SNR 300. The areas covered are steady state and transient conditions, upset and emergency temperature transients, and requirements due to sodium-water reactions. (author)

Operating conditions of steam generators for LMFBR's

International Nuclear Information System (INIS)

Ratzel, W.

1975-01-01

Operating conditions considered to be appropriate for a LMFBR steam generator are discussed on the example of the SNR 300. The areas covered are steady state and transient conditions, upset and emergency temperature transients, and requirements due to sodium-water reactions. (author)

Physics of collisionless scrape-off-layer plasma during normal and off-normal Tokamak operating conditions

International Nuclear Information System (INIS)

Hassanein, A.; Konkashbaev, I.

1999-01-01

The structure of a collisionless scrape-off-layer (SOL) plasma in tokamak reactors is being studied to define the electron distribution function and the corresponding sheath potential between the divertor plate and the edge plasma. The collisionless model is shown to be valid during the thermal phase of a plasma disruption, as well as during the newly desired low-recycling normal phase of operation with low-density, high-temperature, edge plasma conditions. An analytical solution is developed by solving the Fokker-Planck equation for electron distribution and balance in the SOL. The solution is in good agreement with numerical studies using Monte-Carlo methods. The analytical solutions provide an insight to the role of different physical and geometrical processes in a collisionless SOL during disruptions and during the enhanced phase of normal operation over a wide range of parameters

On the approximative normal values of multivalued operators in topological vector space

International Nuclear Information System (INIS)

Nguyen Minh Chuong; Khuat van Ninh

1989-09-01

In this paper the problem of approximation of normal values of multivalued linear closed operators from topological vector Mackey space into E-space is considered. Existence of normal value and convergence of approximative values to normal value are proved. (author). 4 refs

78 FR 76249 - Special Conditions: Airbus, Model A350-900 Series Airplane; Flight Envelope Protection: Normal...

Science.gov (United States)

2013-12-17

..., and accommodates side-by-side placement of LD-3 containers in the cargo compartment. The basic Airbus... availability of this excess maneuver capacity in case of extreme emergency such as upset recoveries or... factor must not be less than: (a) 2.5g for the EFCS normal state with the high lift devices retracted up...

NEPP Update of Independent Single Event Upset Field Programmable Gate Array Testing

Science.gov (United States)

Berg, Melanie; Label, Kenneth; Campola, Michael; Pellish, Jonathan

2017-01-01

This presentation provides a NASA Electronic Parts and Packaging (NEPP) Program update of independent Single Event Upset (SEU) Field Programmable Gate Array (FPGA) testing including FPGA test guidelines, Microsemi RTG4 heavy-ion results, Xilinx Kintex-UltraScale heavy-ion results, Xilinx UltraScale+ single event effect (SEE) test plans, development of a new methodology for characterizing SEU system response, and NEPP involvement with FPGA security and trust.

Operational-safety advantages of LMFBR's: the EBR-II experience and testing program

International Nuclear Information System (INIS)

Sackett, J.I.; Lindsay, R.W.; Golden, G.H.

1982-01-01

LMFBR's contain many inherent characteristics that simplify control and improve operating safety and reliability. The EBR-II design is such that good advantage was taken of these characteristics, resulting in a vary favorable operating history and allowing for a program of off-normal testing to further demonstrate the safe response of LMFBR's to upsets. The experience already gained, and that expected from the future testing program, will contribute to further development of design and safety criteria for LMFBR's. Inherently safe characteristics are emphasized and include natural convective flow for decay heat removal, minimal need for emergency power and a large negative reactivity feedback coefficient. These characteristics at EBR-II allow for ready application of computer diagnosis and control to demonstrate their effectiveness in response to simulated plant accidents. This latter testing objective is an important part in improvements in the man-machine interface

Implications of the spatial dependence of the single-event-upset threshold in SRAMs measured with a pulsed laser

International Nuclear Information System (INIS)

Buchner, S.; Langworthy, J.B.; Stapor, W.J.; Campbell, A.B.; Rivet, S.

1994-01-01

Pulsed laser light was used to measure single event upset (SEU) thresholds for a large number of memory cells in both CMOS and bipolar SRAMs. Results showed that small variations in intercell upset threshold could not explain the gradual rise in the curve of cross section versus linear energy transfer (LET). The memory cells exhibited greater intracell variations implying that the charge collection efficiency within a memory cell varies spatially and contributes substantially to the shape of the curve of cross section versus LET. The results also suggest that the pulsed laser can be used for hardness-assurance measurements on devices with sensitive areas larger than the diameter of the laser beam

Simulation Study of Flap Effects on a Commercial Transport Airplane in Upset Conditions

Science.gov (United States)

Cunningham, Kevin; Foster, John V.; Shah, Gautam H.; Stewart, Eric C.; Ventura, Robin N.; Rivers, Robert A.; Wilborn, James E.; Gato, William

2005-01-01

As part of NASA's Aviation Safety and Security Program, a simulation study of a twinjet transport airplane crew training simulation was conducted to address fidelity for upset or loss of control conditions and to study the effect of flap configuration in those regimes. Piloted and desktop simulations were used to compare the baseline crew training simulation model with an enhanced aerodynamic model that was developed for high-angle-of-attack conditions. These studies were conducted with various flap configurations and addressed the approach-to-stall, stall, and post-stall flight regimes. The enhanced simulation model showed that flap configuration had a significant effect on the character of departures that occurred during post-stall flight. Preliminary comparisons with flight test data indicate that the enhanced model is a significant improvement over the baseline. Some of the unrepresentative characteristics that are predicted by the baseline crew training simulation for flight in the post-stall regime have been identified. This paper presents preliminary results of this simulation study and discusses key issues regarding predicted flight dynamics characteristics during extreme upset and loss-of-control flight conditions with different flap configurations.

Some aspects of barreling in sintered plain carbon steel powder metallurgy preforms during cold upsetting

Directory of Open Access Journals (Sweden)

Sumesh Narayan

2012-04-01

Full Text Available The present research establishes a relationship of bulged diameter with densification and hydrostatic stress in forming of sintered iron (Fe powder metallurgy preforms cold upset under two different frictional conditions, namely, nil/no and graphite lubricant condition. Sintered plain carbon steel cylindrical preforms with carbon (C contents of 0, 0.35, 0.75 and 1.1% with constant initial theoretical density of 84% and aspect ratio of 0.4 and 0.6 were prepared using a suitable die-set assembly on a 1 MN capacity hydraulic press and sintered for 90 minutes at 1200 °C. Each sintered preform was cold upset under two different frictional constraints. It is seen that the degree of bulging reduces with reducing frictional constraints at the die contact surface. Further, it is found that the bulging ratio changed as a function of relative density and hydrostatic stress, respectively, according to the power law equations.

Overview Report: Normal and Emergency Operation Visualization

Energy Technology Data Exchange (ETDEWEB)

Greitzer, Frank L.

2011-05-01

This is an overview report to document and illustrate methods used in a project entitled “Normal and Emergency Operations Visualization” for a utility company, conducted in 2009-2010 timeframe with funding from the utility company and the U.S. Department of Energy. The original final report (about 180 pages) for the project is not available for distribution because it alludes to findings that assessed the design of an operational system that contained proprietary information; this abridged version contains descriptions of methods and some findings to illustrate the approach used, while avoiding discussion of sensitive or proprietary information. The client has approved this abridged version of the report for unlimited distribution to give researchers and collaborators the benefit of reviewing the research concepts and methods that were applied in this study.

Computing in the presence of soft bit errors. [caused by single event upset on spacecraft

Science.gov (United States)

Rasmussen, R. D.

1984-01-01

It is shown that single-event-upsets (SEUs) due to cosmic rays are a significant source of single bit error in spacecraft computers. The physical mechanism of SEU, electron hole generation by means of Linear Energy Transfer (LET), it discussed with reference made to the results of a study of the environmental effects on computer systems of the Galileo spacecraft. Techniques for making software more tolerant of cosmic ray effects are considered, including: reducing the number of registers used by the software; continuity testing of variables; redundant execution of major procedures for error detection; and encoding state variables to detect single-bit changes. Attention is also given to design modifications which may reduce the cosmic ray exposure of on-board hardware. These modifications include: shielding components operating in LEO; removing low-power Schottky parts; and the use of CMOS diodes. The SEU parameters of different electronic components are listed in a table.

Computerized Operator Support System – Phase II Development

Energy Technology Data Exchange (ETDEWEB)

Ulrich, Thomas A.; Boring, Ronald L.; Lew, Roger T.; Thomas, Kenneth D.

2015-02-01

A computerized operator support system (COSS) prototype for nuclear control room process control is proposed and discussed. The COSS aids operators in addressing rapid plant upsets that would otherwise result in the shutdown of the power plant and interrupt electrical power generation, representing significant costs to the owning utility. In its current stage of development the prototype demonstrates four advanced functions operators can use to more efficiently monitor and control the plant. These advanced functions consist of: (1) a synthesized and intuitive high level overview display of system components and interrelations, (2) an enthalpy-based mathematical chemical and volume control system (CVCS) model to detect and diagnose component failures, (3) recommended strategies to mitigate component failure effects and return the plant back to pre-fault status, and (4) computer-based procedures to walk the operator through the recommended mitigation actions. The COSS was demonstrated to a group of operators and their feedback was collected. The operators responded positively to the COSS capabilities and features and indicated the system would be an effective operator aid. The operators also suggested several additional features and capabilities for the next iteration of development. Future versions of the COSS prototype will include additional plant systems, flexible computer-based procedure presentation formats, and support for simultaneous component fault diagnosis and dual fault synergistic mitigation action strategies to more efficiently arrest any plant upsets.

An operator support system for research reactor operations and fault diagnosis through a connectionist framework and PSA based knowledge based systems

International Nuclear Information System (INIS)

Varde, P.V.; Sankar, S.; Verma, A.K.

1998-01-01

During reactor upset/abnormal conditions, emphasis is placed on the plant operator's ability to quickly identify the problem and perform diagnosis and initiate recovery action to ensure the safety of the plant. However, the reliability of human action is adversely affected at the time of crisis due to time stress and psychological factors. The availability of operational aids capable of monitoring the status of the plant and quickly identifying the deviation from normal operation is expected to significantly improve the operator reliability. The development of operator support systems using probabilistic safety assessment (PSA) techniques and information is finding wide application in nuclear plant operation. Often it is observed that most of the applications use a rule-based approach for diagnosis as well as safety status/transient conditions monitoring. A more efficient approach using artificial neural networks for safety status/transient condition monitoring and rule-based systems for diagnosis and emergency procedure generation has been applied for the development of a prototype operator adviser (OPAD) system for a 100 MW(th) heavy water moderated, cooled and natural uranium fueled research reactor. The development objective of this system is to improve the reliability of operator action and hence the reactor safety at the time of crisis as well as in normal operation. In order to address safety objectives at various stages of development of OPAD, the PSA techniques and tools have been used for knowledge representation. It has been demonstrated, with recall tests on the artificial neural network, that it can efficiently identify the reactor status in real-time scenario. This paper discusses various issues related to the development of an operator support system in a comprehensive way, right from the study of safety objectives, to data collection, to implementation of such a system

Single event upsets calculated from new ENDF/B-VI proton and neutron data up to 150 MeV

International Nuclear Information System (INIS)

Chadwick, M.B.

1999-01-01

Single-event upsets (SEU) in microelectronics are calculated from newly-developed silicon nuclear reaction recoil data that extend up to 150 MeV, for incident protons and neutrons. Calculated SEU cross sections are compared with measured data

On the Similarity of Sturm-Liouville Operators with Non-Hermitian Boundary Conditions to Self-Adjoint and Normal Operators

Czech Academy of Sciences Publication Activity Database

Krejčiřík, David; Siegl, Petr; Železný, Jakub

2014-01-01

Roč. 8, č. 1 (2014), s. 255-281 ISSN 1661-8254 R&D Projects: GA MŠk LC06002; GA MŠk LC527; GA ČR GAP203/11/0701 Grant - others:GA ČR(CZ) GD202/08/H072 Institutional support: RVO:61389005 Keywords : Sturm-Liouville operators * non-symmetric Robin boundary conditions * similarity to normal or self-adjoint operators * discrete spectral operator * complex symmetric operator * PT-symmetry * metric operator * C operator * Hilbert- Schmidt operators Subject RIV: BE - Theoretical Physics Impact factor: 0.545, year: 2014

Proton induced single event upset cross section prediction for 0.15 μm six-transistor (6T) silicon-on-insulator static random access memories

International Nuclear Information System (INIS)

Li Lei; Zhou Wanting; Liu Huihua

2012-01-01

In this paper, an efficient physics-based method to estimate the saturated proton upset cross section for six-transistor (6T) silicon-on-insulator (SOI) static random access memory (SRAM) cells using layout and technology parameters is proposed. This method calculates the effects of radiation based on device physics. The simple method handles the problem with ease by SPICE simulations, which can be divided into two stages. At first, it uses a standard SPICE program to predict the cross section for recoiling heavy ions with linear energy transfer (LET) of 14 MeV-cm 2 /mg. Then, the predicted cross section for recoiling heavy ions with LET of 14 MeV-cm 2 /mg is used to estimate the saturated proton upset cross section for 6T SOI SRAM cells with a simple model. The calculated proton induced upset cross section based on this method is in good agreement with the test results of 6T SOI SRAM cells processed using 0.15 μm technology. (author)

Single Event Upset Energy Dependence In a Buck-Converter Power Supply Design

CERN Document Server

Drake, G; The ATLAS collaboration; De Lurgio, P; Stanek, R; Mellado, B; Gopalakrishnan, A; Mahadik, S; Reed, R; Senthilkumaran, A

2012-01-01

We present a study of Single Event Upsets performed on a commercial pulse-width modulator controller chip that we are using for a switching power supply design for the Atlas Tile Calorimeter at the LHC. We performed tests to study the probability of an SEU occurring as a function of incident particle (hadron) energy. We compare the results with prediction from theory. We discuss the performance of the circuit, and perform an analysis using Bendel parameters. We also present a solution that we found using external circuitry that eliminates the effect.

Three-dimensional simulation of charge collection and multiple-bit upset in Si devices

International Nuclear Information System (INIS)

Dodd, P.E.; Sexton, F.W.; Winokur, P.S.

1994-01-01

In this paper, three-dimensional numerical simulation is used to explore the basic charge-collection mechanisms in silicon n + /p diodes. For diodes on lightly-doped substrates ( 15 cm -3 ) struck by a 100-MeV Fe ion, the funneling effect is very strong and essentially all collection is by funnel-assisted drift. This drift collection may occur as late as several nanoseconds after the strike, later than is usually associated with drift collection. For moderately-doped substrates (∼1 x 10 16 cm -3 ) and epitaxial structures grown on heavily-doped substrates, the funnel effect is weaker and drift and diffusion are of more equal importance. For 5-MeV He (α-particle) strikes with low-density charge tracks, the charge-collection transient exhibits both drift and diffusion regimes regardless of the substrate doping. Simulations of diodes with passive external loads indicate that while the current response is altered considerably by the load, total collected charge is not greatly affected for the simple resistive loads studied. Three-dimensional mixed-mode simulation is performed to investigate charge-collection behavior and upset mechanisms in complete CMOS SRAM cells. Simulations of double SRAM cell structures indicate that only collection by diffusion from ''between-node'' strikes is capable of producing multiple-bit upsets in the simulated technology. Limitations of the simulations, specifically carrier-carrier scattering models and large concentration gradients, are also discussed

Intrinsic-normal-ordered vertex operators from the multiloop N-tachyon amplitude

International Nuclear Information System (INIS)

Aldazabal, G.; Nunez, C.; Bonini, M.; Iengo, R.

1987-09-01

We construct vertex operators for arbitrary mass level states of the closed bosonic string. Starting from a generalization of the Koba-Nielsen amplitude which is suitable for an arbitrary genus Riemann surface, we read the vertex operators from the residues of the poles for the intermediate states. Since the original expression is metric independent and normal ordered without the need of inventing any regularization scheme, our vertex operators also possess these properties. We discuss their general features. (author). 17 refs

Single event upsets in semiconductor devices induced by highly ionising particles.

Science.gov (United States)

Sannikov, A V

2004-01-01

A new model of single event upsets (SEUs), created in memory cells by heavy ions and high energy hadrons, has been developed. The model takes into account the spatial distribution of charge collection efficiency over the cell area not considered in previous approaches. Three-dimensional calculations made by the HADRON code have shown good agreement with experimental data for the energy dependence of proton SEU cross sections, sensitive depths and other SEU observables. The model is promising for prediction of SEU rates for memory chips exposed in space and in high-energy experiments as well as for the development of a high-energy neutron dosemeter based on the SEU effect.

Characterization of System Level Single Event Upset (SEU) Responses using SEU Data, Classical Reliability Models, and Space Environment Data

Science.gov (United States)

Berg, Melanie; Label, Kenneth; Campola, Michael; Xapsos, Michael

2017-01-01

We propose a method for the application of single event upset (SEU) data towards the analysis of complex systems using transformed reliability models (from the time domain to the particle fluence domain) and space environment data.

Application of RADSAFE to Model Single Event Upset Response of a 0.25 micron CMOS SRAM

Science.gov (United States)

Warren, Kevin M.; Weller, Robert A.; Sierawski, Brian; Reed, Robert A.; Mendenhall, Marcus H.; Schrimpf, Ronald D.; Massengill, Lloyd; Porter, Mark; Wilkerson, Jeff; LaBel, Kenneth A.;

Simple eigenvectors of unbounded operators of the type “normal plus compact”

Directory of Open Access Journals (Sweden)

Michael Gil'

2015-01-01

Full Text Available The paper deals with operators of the form \\(A=S+B\\, where \\(B\\ is a compact operator in a Hilbert space \\(H\\ and \\(S\\ is an unbounded normal one in \\(H\\, having a compact resolvent. We consider approximations of the eigenvectors of \\(A\\, corresponding to simple eigenvalues by the eigenvectors of the operators \\(A_n=S+B_n\\ (\\(n=1,2, \\ldots\\, where \\(B_n\\ is an \\(n\\-dimensional operator. In addition, we obtain the error estimate of the approximation.

Single event upset and charge collection measurements using high energy protons and neutrons

International Nuclear Information System (INIS)

Normand, E.; Oberg, D.L.; Wert, J.L.; Ness, J.D.; Majewski, P.P.; Wender, S.; Gavron, A.

1994-01-01

RAMs, microcontrollers and surface barrier detectors were exposed to beams of high energy protons and neutrons to measure the induced number of upsets as well as energy deposition. The WNR facility at Los Alamos provided a neutron spectrum similar to that of the atmospheric neutrons. Its effect on devices was compared to that of protons with energies of 200, 400, 500, and 800 MeV. Measurements indicate that SEU cross sections for 400 MeV protons are similar to those induced by the atmospheric neutron spectrum

Investigation of Single Events Upsets in Silicon and GaAs Structures Using Reaction Calculations

Science.gov (United States)

1994-09-01

Cubed Corporation. The CREME (Cosmic-Ray-Effects on Microelectronics) (73) and the CRUP (Cos- mic Ray Upset Program) (74) are both from the Naval...knowledge, that is impossible to do in advance. The errors per bit day calculated using CREME and CRUP for a device exposed to Adams’ 90% worst-case...emitter junction was measured for alpha particles ion measurements and used in CREME (2) and CRUP from an Americium source in two ways: First, the (3

Operational Readiness Review Final Report for K Basin Fuel Transfer System

International Nuclear Information System (INIS)

DAVIES, T.H.

2002-01-01

An Operational Readiness Review (ORR) was conducted by the U.S. Department of Energy (DOE), Richland Operations Office (RL) to verify that an adequate state of readiness had been achieved for startup of the K Basin Fuel Transfer System (FTS). The DOE ORR was conducted during the period November 6-18, 2002. The DOE ORR team concluded that the K Basin Fuel Transfer System is ready to start operations, subject to completion and verification of identified pre-start findings. The ORR was conducted in accordance with the Spent Nuclear Fuel (SNF) K Basin Fuel Transfer System (FTS) Operational Readiness Review (ORR) Plan of Action and the Operational Readiness Review Implementation Plan for K Basin Fuel Transfer System. Review activities consisted of staff interviews, procedure and document reviews, and observations of normal facility operations, operational upset conditions, and an emergency drill. The DOE ORR Team also reviewed and assessed the adequacy of the contractor ORR3 and the RL line management review. The team concurred with the findings and observations identified in these two reports. The DOE ORR for the FTS evaluated the contractor under single-shift operations. Of concern to the ORR Team was that SNF Project management intended to change from a single-shift FTS operation to a two-shift operation shortly after the completion of the DOE ORR. The ORR team did not assess two-shift FTS operations and the ability of the contractor to conduct a smooth transition from shift to shift. However, the DOE ORR team did observe an operational upset drill that was conducted during day shift and carried over into swing shift; during this drill, swing shift was staffed with fewer personnel as would be expected for two-shift operations. The facility was able to adequately respond to the event with the reduced level of staff. The ORR Team was also able to observe a Shift Manager turnover meeting when one shift manager had to be relieved during the middle of the day. The ORR

Radiological Impacts Assessment during Normal Decommissioning Operation for EU-APR

Energy Technology Data Exchange (ETDEWEB)

Hwang, Do Hyun; Lee, Keun Sung [KHNP CRI, Daejeon (Korea, Republic of); Lee, ChongHui [KEPCO Engineering and Construction, Gimcheon (Korea, Republic of)

2016-10-15

In this paper, radiological impacts on human beings during normal execution of the decommissioning operations from the current standard design of EU-APR which has been modified and improved from its original design of APR1400 to comply with EUR, are evaluated. Decommissioning is the final phase in the life cycle of a nuclear installation, covering all activities from shutdown and removal of fissile material to environmental restoration of the site. According to article 5.4 specified in chapter 2.20 of European Utility Requirements (EUR), all relevant radiological impacts on human being should be considered during the environmental assessment of decommissioning, including external exposure from direct radiation of plant and other radiation sources, and internal exposure due to inhalation and ingestion. In this paper, radiological impacts on human beings during normal circumstances of the decommissioning operation were evaluated from the current standard design of EU-APR based on the simple transport model and practical generic methodology for assessing the radiological impact provided by IAEA. The results of dose assessment fulfilled the dose limit for all scenarios.

Identification of passive shutdown system parameters in a metal fueled LMR

International Nuclear Information System (INIS)

Vilim, R.B.

1992-01-01

This document discusses periodic testing of the passive shutdown system in a metal fueled liquid metal reactor which has been proposed as a Technical Specification requirement. In the approach to testing considered in this paper, perturbation experiments performed at normal operation are used to predict an envelope that bounds reactor response to flowrate, inlet temperature and external reactivity forcing functions. When the envelope for specific upsets lies within safety limits, one concludes that the passive shutdown system is operation properly for those upsets. Simulation results for the EBR-II reactor show that the response envelope for loss of flow and rod reactivity insertion events does indeed bound these events

Calculation of neutron-induced single-event upset cross sections for semiconductor memory devices

International Nuclear Information System (INIS)

Ikeuchi, Taketo; Watanabe, Yukinobu; Nakashima, Hideki; Sun, Weili

2001-01-01

Neutron-induced single-event upset (SEU) cross sections for semiconductor memory devices are calculated by the Burst Generation Rate (BGR) method using LA150 data and QMD calculation in the neutron energy range between 20 MeV and 10 GeV. The calculated results are compared with the measured SEU cross sections for energies up to 160 MeV, and the validity of the calculation method and the nuclear data used is verified. The kind of reaction products and the neutron energy range that have the most effect on SEU are discussed. (author)

Analyzing Test-As-You-Fly Single Event Upset (SEU) Responses using SEU Data, Classical Reliability Models, and Space Environment Data

Science.gov (United States)

Berg, Melanie; Label, Kenneth; Campola, Michael; Xapsos, Michael

2017-01-01

We propose a method for the application of single event upset (SEU) data towards the analysis of complex systems using transformed reliability models (from the time domain to the particle fluence domain) and space environment data.

Single event upset threshold estimation based on local laser irradiation

International Nuclear Information System (INIS)

Chumakov, A.I.; Egorov, A.N.; Mavritsky, O.B.; Yanenko, A.V.

1999-01-01

An approach for estimation of ion-induced SEU threshold based on local laser irradiation is presented. Comparative experiment and software simulation research were performed at various pulse duration and spot size. Correlation of single event threshold LET to upset threshold laser energy under local irradiation was found. The computer analysis of local laser irradiation of IC structures was developed for SEU threshold LET estimation. The correlation of local laser threshold energy with SEU threshold LET was shown. Two estimation techniques were suggested. The first one is based on the determination of local laser threshold dose taking into account the relation of sensitive area to local irradiated area. The second technique uses the photocurrent peak value instead of this relation. The agreement between the predicted and experimental results demonstrates the applicability of this approach. (authors)

An Approach for the Assessment of System Upset Resilience

Science.gov (United States)

Torres-Pomales, Wilfredo

2013-01-01

This report describes an approach for the assessment of upset resilience that is applicable to systems in general, including safety-critical, real-time systems. For this work, resilience is defined as the ability to preserve and restore service availability and integrity under stated conditions of configuration, functional inputs and environmental conditions. To enable a quantitative approach, we define novel system service degradation metrics and propose a new mathematical definition of resilience. These behavioral-level metrics are based on the fundamental service classification criteria of correctness, detectability, symmetry and persistence. This approach consists of a Monte-Carlo-based stimulus injection experiment, on a physical implementation or an error-propagation model of a system, to generate a system response set that can be characterized in terms of dimensional error metrics and integrated to form an overall measure of resilience. We expect this approach to be helpful in gaining insight into the error containment and repair capabilities of systems for a wide range of conditions.

Relationship between single-event upset immunity and fabrication processes of recent memories; Relations entre l'immunite au SEU et les procedes de fabrication de memoires recentes

Energy Technology Data Exchange (ETDEWEB)

Nemoto, N.; Shindou, H.; Kuboyama, S.; Matsuda, S. [National Space Development Agency of Japan, Ibaraki-ken (Japan); Itoh, H.; Okada, S.; Nashiyama, I. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan)

1999-07-01

Single-Event upset (SEU) immunity for commercial devices were evaluated by irradiation tests using high-energy heavy ions. We show test results and describe the relationship between observed SEU and structures/fabrication processes. We have evaluated single-even upset (SEU) tolerance of recent commercial memory devices using high energy heavy ions in order to find relationship between SEU rate and their fabrication process. It was revealed that the change of the process parameter gives much effect for the SEU rate of the devices. (authors)

Occupational and Public Exposure During Normal Operation of Radioactive Waste Disposal Facilities

OpenAIRE

M. V. Vedernikova; I. A. Pron; M. N. Savkin; N. S. Cebakovskaya

2017-01-01

This paper focuses on occupational and public exposure during operation of disposal facilities receiving liquid and solid radioactive waste of various classes and provides a comparative analysis of the relevant doses: actual and calculated at the design stage. Occupational and public exposure study presented in this paper covers normal operations of a radioactive waste disposal facility receiving waste. Results: Analysis of individual and collective occupational doses was performed based on d...

Estimation of the LET threshold of single event upset of microelectronics in experiments with Cf-252

International Nuclear Information System (INIS)

Kuznetsov, N.V.; Nymmik, R.A.

1996-01-01

A method is proposed for analyzing single event upsets (SEU) in large scale integration circuits of random access memory (RAM) when exposed to Cf-252 fission fragments. The method makes is possible to find the RAM linear energy transfer (LET) threshold to be used for estimations of RAM SEU rates in space. The method is illustrated by analyzing experimental data for the 2 x 8 kbit CMOS/bulk RAM. (author)

Mechanical stress analysis for a fuel rod under normal operating conditions

International Nuclear Information System (INIS)

Pino, Eddy S.; Giovedi, Claudia; Serra, Andre da Silva; Abe, Alfredo Y.

2013-01-01

Nuclear reactor fuel elements consist mainly in a system of a nuclear fuel encapsulated by a cladding material subject to high fluxes of energetic neutrons, high operating temperatures, pressure systems, thermal gradients, heat fluxes and with chemical compatibility with the reactor coolant. The design of a nuclear reactor requires, among a set of activities, the evaluation of the structural integrity of the fuel rod submitted to different loads acting on the fuel rod and the specific properties (dimensions and mechanical and thermal properties) of the cladding material and coolant, including thermal and pressure gradients produced inside the rod due to the fuel burnup. In this work were evaluated the structural mechanical stresses of a fuel rod using stainless steel as cladding material and UO 2 with a low degree of enrichment as fuel pellet on a PWR (pressurized water reactor) under normal operating conditions. In this sense, tangential, radial and axial stress on internal and external cladding surfaces considering the orientations of 0 deg, 90 deg and 180 deg were considered. The obtained values were compared with the limit values for stress to the studied material. From the obtained results, it was possible to conclude that, under the expected normal reactor operation conditions, the integrity of the fuel rod can be maintained. (author)

A COMPUTERIZED OPERATOR SUPPORT SYSTEM PROTOTYPE

Energy Technology Data Exchange (ETDEWEB)

Thomas A. Ulrich; Roger Lew; Ronald L. Boring; Ken Thomas

2015-03-01

A computerized operator support system (COSS) is proposed for use in nuclear power plants to assist control room operators in addressing time-critical plant upsets. A COSS is a collection of technologies to assist operators in monitoring overall plant performance and making timely, informed decisions on appropriate control actions for the projected plant condition. A prototype COSS was developed in order to demonstrate the concept and provide a test bed for further research. The prototype is based on four underlying elements consisting of a digital alarm system, computer-based procedures, piping and instrumentation diagram system representations, and a recommender module for mitigation actions. The initial version of the prototype is now operational at the Idaho National Laboratory using the Human System Simulation Laboratory.

Results of dose calculations for NET accidental and normal operation releases of tritium and activation products

International Nuclear Information System (INIS)

Raskob, W.; Hasemann, I.

1992-08-01

This report documents conditions, data and results of dose calculations for accidental and normal operation releases of tritium and activation products, performed within the NET subtask SEP2.2 ('NET-Benchmark') of the European Fusion Technology Programme. For accidental releases, the computer codes UFOTRI and COSYMA for assessing the radiological consequences, have been applied for both deterministic and probabilistic calculations. The influence on dose estimates of different release times (2 minutes / 1 hour), two release heights (10 m / 150 m), two chemical forms of tritium (HT/HTO), and two different model approaches for the deposition velocity of HTO on soil was investigated. The dose calculations for normal operation effluents were performed using the tritium model of the German regulatory guidelines, parts of the advanced dose assessment model NORMTRI still under development, and the statistical atmospheric dispersion model ISOLA. Accidental and normal operation source terms were defined as follows: 10g (3.7 10 15 Bq) for accidental tritium releases, 10 Ci/day (3.7 10 11 Bq/day) for tritium releases during normal operation and unit releases of 10 9 Bq for accidental releases of activation products and fission products. (orig./HP) [de

Crying without a cause and being easily upset in two-year-olds: heritability and predictive power of behavioral problems

NARCIS (Netherlands)

Groen-Blokhuis, Maria M.; Middeldorp, Christel M.; van Beijsterveldt, Catharina E.; Boomsma, Dorret I.

2011-01-01

In order to estimate the influence of genetic and environmental factors on 'crying without a cause' and 'being easily upset' in 2-year-old children, a large twin study was carried out. Prospective data were available for ~18,000 2-year-old twin pairs from the Netherlands Twin Register. A bivariate

Prediction of the time-dependent failure rate for normally operating components taking into account the operational history

International Nuclear Information System (INIS)

Vrbanic, I.; Simic, Z.; Sljivac, D.

2008-01-01

The prediction of the time-dependent failure rate has been studied, taking into account the operational history of a component used in applications such as system modeling in a probabilistic safety analysis in order to evaluate the impact of equipment aging and maintenance strategies on the risk measures considered. We have selected a time-dependent model for the failure rate which is based on the Weibull distribution and the principles of proportional age reduction by equipment overhauls. Estimation of the parameters that determine the failure rate is considered, including the definition of the operational history model and likelihood function for the Bayesian analysis of parameters for normally operating repairable components. The operational history is provided as a time axis with defined times of overhauls and failures. An example for demonstration is described with prediction of the future behavior for seven different operational histories. (orig.)

Crying Without a Cause and Being Easily Upset in Two-Year-Olds: Heritability and Predictive Power of Behavioral Problems

NARCIS (Netherlands)

Groen-Blokhuis, M.M.; Middeldorp, C.M.; van Beijsterveldt, C.E.M.; Boomsma, D.I.

2011-01-01

In order to estimate the influence of genetic and environmental factors on 'crying without a cause' and 'being easily upset' in 2-year-old children, a large twin study was carried out. Prospective data were available for ∼18,000 2-year-old twin pairs from the Netherlands Twin Register. A bivariate

Assessment of risks of accidents and normal operation at nuclear power plants

International Nuclear Information System (INIS)

Savolainen, Ilkka; Vuori, Seppo.

1977-01-01

A probabilistic assessment model for the analysis of risks involved in the operation of nuclear power plants is described. With the computer code ARANO it is possible to estimate the health and economic consequences of reactor accidents both in probabilistic and deterministic sense. In addition the code is applicable to the calculation of individual and collective doses caused by the releases during normal operation. The estimation of release probabilities and magnitudes is not included in the model. (author)

Low-energy neutron-induced single-event upsets in static random access memory

International Nuclear Information System (INIS)

Guo Xiaoqiang; Guo Hongxia; Wang Guizhen; Ling Dongsheng; Chen Wei; Bai Xiaoyan; Yang Shanchao; Liu Yan

2009-01-01

The visual analysis method of data process was provided for neutron-induced single-event upset(SEU) in static random access memory(SRAM). The SEU effects of six CMOS SRAMs with different feature size(from 0.13 μm to 1.50 μm) were studied. The SEU experiments were performed using the neutron radiation environment at Xi'an pulsed reactor. And the dependence of low-energy neutron-induced SEU cross section on SRAM's feature size was given. The results indicate that the decreased critical charge is the dominant factor for the increase of single event effect sensitivity of SRAM devices with decreased feature size. Small-sized SRAM devices are more sensitive than large-sized ones to single event effect induced by low-energy neutrons. (authors)

Structural analysis of 177-FA redesigned surveillance specimen holder tube

International Nuclear Information System (INIS)

Pryor, C.W.; Thoren, D.E.; Vames, G.J.; Harris, R.J.

1976-08-01

Because of in-service operational problems, the surveillance specimen holder tubes described in B and W topical report BAW-10051 have been redesigned. This report describes the new design and structural analysis for normal operation and upset loading conditions. The results of the analysis demonstrate the adequacy of the new surveillance specimen holder tubes for their design life of 40 years

Characterization of System on a Chip (SoC) Single Event Upset (SEU) Responses Using SEU Data, Classical Reliability Models, and Space Environment Data

Science.gov (United States)

Berg, Melanie; Label, Kenneth; Campola, Michael; Xapsos, Michael

2017-01-01

We propose a method for the application of single event upset (SEU) data towards the analysis of complex systems using transformed reliability models (from the time domain to the particle fluence domain) and space environment data.

Assessment of radiation doses due to normal operation, incidents and accidents of the final disposal facility

International Nuclear Information System (INIS)

Rossi, J.; Raiko, H.; Suolanen, V.; Ilvonen, M.

1999-03-01

Radiation doses for workers of the encapsulation and disposal facility and for inhabitants in the environment caused by the facility during its operation were considered. The study covers both the normal operation of the plant and some hypothetical incidents and accidents. Occupational radiation doses inside the plant during normal operation are based on the design basis, assuming that highest permitted dose levels are prevailing in control rooms during fuel transfer and encapsulation processes. Release through the ventilation stack is assumed to be filtered both in normal operation and in hypothetical incident and accident cases. Calculation of the offsite doses from normal operation is based on the hypothesis that one fuel pin per 100 fuel bundles for all batches of spent fuel transported to the encapsulation facility is leaking. The release magnitude in incidents and accidents is based on the event chains, which lead to loss of fuel pin tightness followed by a discharge of radionuclides into the handling chamber and to some degree through the ventilation stack into atmosphere. The weather data measured at the Olkiluoto meteorological mast was employed for calculating of offsite doses. Therefore doses could be calculated in a large amount of different dispersion conditions, the statistical frequencies of which have, been measured. Finally doses were combined into cumulative distributions, from which a dose value representing the 99.5 % confidence level, is presented. The dose values represent the exposure of a critical group, which is assumed to live at the distance of 200 meters from the encapsulation and disposal plant and thus it will receive the largest doses in most dispersion conditions. Exposure pathways considered were: cloudsnine, inhalation, groundshine and nutrition (milk of cow, meat of cow, green vegetables, grain and root vegetables). Nordic seasonal variation is included in ingestion dose models. The results obtained indicate that offsite doses

Operational Problems Associated with Head-Up Displays during Instrument Flight.

Science.gov (United States)

1980-10-01

Force project engineers were Major Michael F. Rundle and Mr. William L. Welde . 41 4 TABLE OF CONTENTS Page ABBREVIATIONS...of Automotive Engineers SETP Society of Experimental Test Pilots SI Solid Instruments SNPL Syndicat National des Pilotes des Lignes (French ALPA) TACAN...Factors Relevent to Jet Upsets ," Lessons with Emphasis on Flight Mechanics from Operating Experience, Incidents, and Accidents, AGARD CP-76, 1971 153 J

Dioxins from medical waste incineration: Normal operation and transient conditions.

Science.gov (United States)

Chen, Tong; Zhan, Ming-xiu; Yan, Mi; Fu, Jian-ying; Lu, Sheng-yong; Li, Xiao-dong; Yan, Jian-hua; Buekens, Alfons

2015-07-01

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are key pollutants in waste incineration. At present, incinerator managers and official supervisors focus only on emissions evolving during steady-state operation. Yet, these emissions may considerably be raised during periods of poor combustion, plant shutdown, and especially when starting-up from cold. Until now there were no data on transient emissions from medical (or hospital) waste incineration (MWI). However, MWI is reputed to engender higher emissions than those from municipal solid waste incineration (MSWI). The emission levels in this study recorded for shutdown and start-up, however, were significantly higher: 483 ± 184 ng Nm(-3) (1.47 ± 0.17 ng I-TEQ Nm(-3)) for shutdown and 735 ng Nm(-3) (7.73 ng I-TEQ Nm(-3)) for start-up conditions, respectively. Thus, the average (I-TEQ) concentration during shutdown is 2.6 (3.8) times higher than the average concentration during normal operation, and the average (I-TEQ) concentration during start-up is 4.0 (almost 20) times higher. So monitoring should cover the entire incineration cycle, including start-up, operation and shutdown, rather than optimised operation only. This suggestion is important for medical waste incinerators, as these facilities frequently start up and shut down, because of their small size, or of lacking waste supply. Forthcoming operation should shift towards much longer operating cycles, i.e., a single weekly start-up and shutdown. © The Author(s) 2015.

Measurements of proton upset induced in Cmos devices synthesis of CEA studies

International Nuclear Information System (INIS)

Mijuin, D.; Buisson, J.; Brunet, J.P.; Murat, J.; Chapuis, T.

1990-01-01

Within its space activities, the Departement d'Electronique et d'Instrumentation Nucleaire (DEIN) is involved in a research program regarding the behaviour of electronic components submitted to the type of radiations encountered in earth orbits or by planetary probes. Located at Saclay, the SATURNE synchrotron is a tool well suited to simulate the effects of high energy cosmic particles. The DEIN has thus carried out several experimental runs in which CMOS SRAM were irradiated with a proton beam. SATURNE is a synchrotron designed for basic research in the physics of light particles and heavy ions of intermediate energy. The energy supplied to the protons lies between 0.2 and 2.9 GeV with an intensity larger than 10 12 protons cycle -1 . During the experiment and in order to lower the proton energy under 200 MeV, an Al-absorber was used. The flux measurement was obtained by two different methods: measurement by activation and measurement by counting (scintillator coupled with a PM). The increase number of upsets during irradiation was determined, on line, for each cycle, by a testor using a comparative hardware method. The testor was designed by the DEIN. Latch-up was also detected. The results, presented in this paper, were obtained during the run of September 1990. The upset cross-sections per bit of static memories MHS 65162. MHS 65641, MOSTEK 48H64 and HYUNDAI 6116 were measured for 1000, 200, 158.9, 147.5, 122.6, 93.3 and 66.2 MeV. These experimental values were fitted using the Bendel equation with two variable parameters proposed by Stapor and al (3). The results of the run of September 1990 encourage us to pursue our studies. By now, it seems necessary to improve the experimental line (elimination of the parasitic effects generated by the Al-absorber) and to upgrade the methods used for measuring the flux

Swift heavy ion induced single event upsets in high density UV-EPROM's

Energy Technology Data Exchange (ETDEWEB)

Dahiwale, S.S. [Department of Physics, University of Pune, Pune 7 (India); Shinde, N.S. [Department of Chemical Engineering, Mie University (Japan); Kanjilal, D. [Inter University Accelerator Center, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 7 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 7 (India)], E-mail: sanjay@physics.unipune.ernet.in

2008-04-15

A few high density UV-EPROM's (32Kb x 8) were irradiated with 5.41 MeV energy {alpha}-particles with fluences from 10{sup 4} to 10{sup 8} alphas/cm{sup 2} and 100 MeV nickel, iodine and silver ions for low fluences between 5 x 10{sup 7} and 10{sup 8} ions/cm{sup 2}. The energy and ion species was selected on the basis of predicted threshold values of linear energy transfer (LET) in silicon. The program which was stored in the memory found to be changed from 0 to 1 and 1 to 0 state, respectively. On the basis of changed states, the cross-sections ({sigma}) were calculated to investigate the single event effects/upsets. No upset was observed in case of {alpha}-particle since it has very low LET, but the SEU cross-section found to be more in case of Iodine i.e. 2.29 x 10{sup -3} cm{sup 2} than that of nickel, 2.12 x 10{sup -3} cm{sup 2} and silver, 2.26 x 10{sup -3}. This mainly attributes that LET for iodine is more as compared to silver and nickel ions, which deposits large amount of energy near the sensitive node of memory cell in the form of electron-hole pairs required to change the state. These measured SEU cross-section were also compared with theoretically predicted values along with the Weibull distribution fit to the ion induced experimental SEU data. The theoretical predicted SEU cross-section 3.27 x 10{sup -3} cm{sup 2} found to be in good agreement with the measured SEU cross-section.

Self-efficacy for controlling upsetting thoughts and emotional eating in family caregivers.

Science.gov (United States)

MacDougall, Megan; Steffen, Ann

2017-10-01

Self-efficacy for controlling upsetting thoughts was examined as a predictor of emotional eating by family caregivers of physically and cognitively impaired older adults. Adult women (N = 158) providing healthcare assistance for an older family member completed an online survey about caregiving stressors, depressive symptoms, self-efficacy, and emotional eating. A stress process framework was used as a conceptual model to guide selection of variables predicting emotional eating scores. A hierarchical multiple regression was conducted and the overall model was significant (R 2 = .21, F(4,153) = 10.02, p accounting for IADL, role overload, and depression scores. These findings replicate previous research demonstrating the relationship between managing cognitions about caregiving and behavioral responses to stressors, and point to the importance of addressing cognitive processes in efforts to improve caregiver health behaviors.

Single-Event Upset and Scaling Trends in New Generation of the Commercial SOI PowerPC Microprocessors

Science.gov (United States)

Irom, Farokh; Farmanesh, Farhad; Kouba, Coy K.

2006-01-01

Single-event upset effects from heavy ions are measured for Motorola silicon-on-insulator (SOI) microprocessor with 90 nm feature sizes. The results are compared with previous results for SOI microprocessors with feature sizes of 130 and 180 nm. The cross section of the 90 nm SOI processors is smaller than results for 130 and 180 nm counterparts, but the threshold is about the same. The scaling of the cross section with reduction of feature size and core voltage for SOI microprocessors is discussed.

Simulation of thermal-neutron-induced single-event upset using particle and heavy-ion transport code system

International Nuclear Information System (INIS)

Arita, Yutaka; Kihara, Yuji; Mitsuhasi, Junichi; Niita, Koji; Takai, Mikio; Ogawa, Izumi; Kishimoto, Tadafumi; Yoshihara, Tsutomu

2007-01-01

The simulation of a thermal-neutron-induced single-event upset (SEU) was performed on a 0.4-μm-design-rule 4 Mbit static random access memory (SRAM) using particle and heavy-ion transport code system (PHITS): The SEU rates obtained by the simulation were in very good agreement with the result of experiments. PHITS is a useful tool for simulating SEUs in semiconductor devices. To further improve the accuracy of the simulation, additional methods for tallying the energy deposition are required for PHITS. (author)

SEE induced in SRAM operating in a superconducting electron linear accelerator environment

Science.gov (United States)

Makowski, D.; Mukherjee, Bhaskar; Grecki, M.; Simrock, Stefan

2005-02-01

Strong fields of bremsstrahlung photons and photoneutrons are produced during the operation of high-energy electron linacs. Therefore, a mixed gamma and neutron radiation field dominates the accelerators environment. The gamma radiation induced Total Ionizing Dose (TID) effect manifests the long-term deterioration of the electronic devices operating in accelerator environment. On the other hand, the neutron radiation is responsible for Single Event Effects (SEE) and may cause a temporal loss of functionality of electronic systems. This phenomenon is known as Single Event Upset (SEU). The neutron dose (KERMA) was used to scale the neutron induced SEU in the SRAM chips. Hence, in order to estimate the neutron KERMA conversion factor for Silicon (Si), dedicated calibration experiments using an Americium-Beryllium (241Am/Be) neutron standard source was carried out. Single Event Upset (SEU) influences the short-term operation of SRAM compared to the gamma induced TID effect. We are at present investigating the feasibility of an SRAM based real-time beam-loss monitor for high-energy accelerators utilizing the SEU caused by fast neutrons. This paper highlights the effects of gamma and neutron radiations on Static Random Access Memory (SRAM), placed at selected locations near the Superconducting Linear Accelerator driving the Vacuum UV Free Electron Laser (VUVFEL) of DESY.

To Leave a Praxis to Itself May Be to Upset It in Unintended Ways

DEFF Research Database (Denmark)

Olsen, Poul Bitsch; Axel, Erik

by the researchers on a conception of situated praxis, of conflictual cooperation, and on an interest in morals and the meaning of upsetting practices. The organization of the material may hopefully provoke discussions around praxis as part of its further development. Thus, our presentation is based on a notion...... of praxis. Praxis is formed by the reciprocal differentiations of acts. In order to be able to act here, we try to arrange things to be done in specific ways there. In order to build the house here, we arrange a supply of inhabitants here, a conglomerate of producers there etc.. Furthermore, what we achieve...

Study on radioactive release of gaseous and liquid effluents during normal operation of AP1000

International Nuclear Information System (INIS)

Gong Quan; Zhou Jing; Liu Yu

2014-01-01

The gaseous and liquid radioactive releases of pressurized water reactors plant during normal operation are an important content of environmental impact assessment and play a significant role in the design of nuclear power plant. According to the design characters of AP1OOO radioactive waste management system and the study on the calculation method and the release pathways, the calculation model of the gaseous and liquid radioactive releases during normal operation for AP1OOO are established. Base on the established calculation model and the design parameters of AP1000, the expected value of gaseous and liquid radioactive releases of AP1OOO is calculated. The results of calculation are compared with the limits in GB 6249-2011 and explain the adder that is included tu account for anticipated operational occurrences, providing a reference for environmental impact assessment of pressurized water reactor. (authors)

Feasibility of a neutron detector-dosemeter based on single-event upsets in dynamic random-access memories

International Nuclear Information System (INIS)

Phillips, G.W.; August, R.A.; Campbell, A.B.; Nelson, M.E.; Guardala, N.A.; Price, J.L.; Moscovitch, M.

2002-01-01

The feasibility was investigated of a solid-state neutron detector/dosemeter based on single-event upset (SEU) effects in dynamic random-access memories (DRAMs), commonly used in computer memories. Such a device, which uses a neutron converter material to produce a charged particle capable of causing an upset, would be light-weight, low-power, and could be read simply by polling the memory for bit flips. It would have significant advantages over standard solid-state neutron dosemeters which require off-line processing for track etching and analysis. Previous efforts at developing an SEU neutron detector/dosemeter have suffered from poor response, which can be greatly enhanced by selecting a modern high-density DRAM chip for SEU sensitivity and by using a thin 10 B film as a converter. Past attempts to use 10 B were not successful because the average alpha particle energy was insufficient to penetrate to the sensitive region of the memory. This can be overcome by removing the surface passivation layer before depositing the 10 B film or by implanting 10B directly into the chip. Previous experimental data show a 10 3 increase in neutron sensitivity by chips containing borosilicate glass, which could be used in an SEU detector. The results are presented of simulations showing that the absolute efficiency of an SEU neutron dosemeter can be increased by at least a factor of 1000 over earlier designs. (author)

Occupational and Public Exposure During Normal Operation of Radioactive Waste Disposal Facilities

Directory of Open Access Journals (Sweden)

M. V. Vedernikova

2017-01-01

Full Text Available This paper focuses on occupational and public exposure during operation of disposal facilities receiving liquid and solid radioactive waste of various classes and provides a comparative analysis of the relevant doses: actual and calculated at the design stage. Occupational and public exposure study presented in this paper covers normal operations of a radioactive waste disposal facility receiving waste. Results: Analysis of individual and collective occupational doses was performed based on data collected during operation of near-surface disposal facilities for short-lived intermediate-, lowand very low-level waste in France, as well as nearsurface disposal facilities for long-lived waste in Russia. Further analysis of occupational and public doses calculated at the design stage was completed covering a near-surface disposal facility in Belgium and deep disposal facilities in the United Kingdom and the Nizhne-Kansk rock massive (Russia. The results show that engineering and technical solutions enable almost complete elimination of internal occupational exposure, whereas external exposure doses would fall within the range of values typical for a basic nuclear facility. Conclusion: radioactive waste disposal facilities being developed, constructed and operated meet the safety requirements effective in the Russian Federation and consistent with relevant international recommendations. It has been found that individual occupational exposure doses commensurate with those received by personnel of similar facilities abroad. Furthermore, according to the forecasts, mean individual doses for personnel during radioactive waste disposal would be an order of magnitude lower than the dose limit of 20 mSv/year. As for the public exposure, during normal operation, potential impact is virtually impossible by delaminating boundaries of a nuclear facility sanitary protection zone inside which the disposal facility is located and can be solely attributed to the use

A capacitively coupled dose-rate-dependent transient upset mechanism in a bipolar memory

International Nuclear Information System (INIS)

Turfler, R.M.; Pease, R.L.; Dinger, G.; Armstrong, B.

1992-01-01

This paper reports on a pattern sensitivity that was observed in the threshold dose rate response of a bipolar 16K PROM for radiation pulse widths of 20-100 ns. For the worst case pattern, the upset threshold was a factor of three lower than for the commonly used checkerboard pattern. The mechanism for this pattern sensitivity was found to be a capacitively coupled voltage transient on a sensitive node which caused a low-to-high transition at the output. A design fix was implemented to significantly alter the ratio of the two parasitic capacitances in a capacitive divider which reduced the amplitude of the voltage transient at the sensitive node. It was demonstrated that in the redesign, the pattern sensitivity was eliminated

Operator-normalized quantum arrival times in the presence of interactions

International Nuclear Information System (INIS)

Hegerfeldt, G.C.; Seidel, D.; Muga, J.G.; Navarro, B.

2004-01-01

We model ideal arrival-time measurements for free quantum particles and for particles subject to an external interaction by means of a narrow and weak absorbing potential. This approach is related to the operational approach of measuring the first photon emitted from a two-level atom illuminated by a laser. By operator normalizing the resulting time-of-arrival distribution, a distribution is obtained which for freely moving particles not only recovers the axiomatically derived distribution of Kijowski for states with purely positive momenta but is also applicable to general momentum components. For particles interacting with a square barrier the mean arrival time and corresponding 'tunneling time' obtained at the transmission side of the barrier become independent of the barrier width (Hartman effect) for arbitrarily wide barriers, i.e., without the transition to the ultraopaque, classical-like regime dominated by wave packet components above the barrier

Experimental Modeling of VHTR Plenum Flows during Normal Operation and Pressurized Conduction Cooldown

Energy Technology Data Exchange (ETDEWEB)

Glenn E McCreery; Keith G Condie

2006-09-01

The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. The present document addresses experimental modeling of flow and thermal mixing phenomena of importance during normal or reduced power operation and during a loss of forced reactor cooling (pressurized conduction cooldown) scenario. The objectives of the experiments are, 1), provide benchmark data for assessment and improvement of codes proposed for NGNP designs and safety studies, and, 2), obtain a better understanding of related phenomena, behavior and needs. Physical models of VHTR vessel upper and lower plenums which use various working fluids to scale phenomena of interest are described. The models may be used to both simulate natural convection conditions during pressurized conduction cooldown and turbulent lower plenum flow during normal or reduced power operation.

Risk assessment of the Krsko NPP normal operation on the public in the Zagreb area

International Nuclear Information System (INIS)

Skanata, D.; Pevec, D.

1994-01-01

In the paper, a very short review of the ICRP recommendations related to effective dose limitation for the workers as well as for the public, is given. Particular attention is paid to the risk coefficients values. In the short manner, description of the applied methodology and achieved result related to the risk assessment of the Krsko NPP normal operation on the public in the Zagreb Area, are given too. The mentioned assessment was performed as an activity within the Case Study Zagreb Project developed under the Inter-Agency Programme on the Assessment and Management of Health and Environmental Risks from Energy and Other Complex Industrial Systems (UNEP, WHO, IAEA and UNIDO). Making comparison between assessment risk of the Krsko NPP normal operation and risks to which inhabitants of the City of Zagreb are normally exposed, it is concluded that living in the vicinity of such nuclear power plant as it is Krsko NPP (PWR, 664 MWe), is not so risky as risky are some everyday activities

Talys calculations for evaluation of neutron-induced single-event upset cross sections

Energy Technology Data Exchange (ETDEWEB)

Bourselier, Jean-Christophe

2005-08-15

The computer code TALYS has been used to calculate interactions between cosmic-ray neutrons and silicon nuclei with the goal to describe single-event upset (SEU) cross sections in microelectronics devices. Calculations for the Si(n,X) reaction extend over an energy range of 2 to 200 MeV. The obtained energy spectra of the resulting residuals and light-ions have been integrated using several different critical charges as SEU threshold. It is found that the SEU cross section seems largely to be dominated by {sup 28}Si recoils from elastic scattering. Furthermore, the shape of the SEU cross section as a function of the energy of the incoming neutron changes drastically with decreasing critical charge. The results presented in this report stress the importance of performing studies at mono-energetic neutron beams to advance the understanding of the underlying mechanisms causing SEUs.

Single Event Upset in Static Random Access Memories in Atmospheric Neutron Environments

Science.gov (United States)

Arita, Yutaka; Takai, Mikio; Ogawa, Izumi; Kishimoto, Tadafumi

2003-07-01

Single-event upsets (SEUs) in a 0.4 μm 4 Mbit complementary metal oxide semiconductor (CMOS) static random access memory (SRAM) were investigated in various atmospheric neutron environments at sea level, at an altitude of 2612 m mountain, at an altitude of commercial airplane, and at an underground depth of 476 m. Neutron-induced SEUs increase with the increase in altitude. For a device with a borophosphosilicate glass (BPSG) film, SEU rates induced by thermal neutrons increase with the decrease in the cell charge of a memory cell. A thermal neutron-induced SEU is significant in SRAMs with a small cell charge. With the conditions of small cell charge, thermal neutron-induced SEUs account for 60% or more of the total neutron-induced SEUs. The SEU rate induced by atmospheric thermal neutrons can be estimated by an acceleration test using 252Cf.

Survey of Quantitative Research Metrics to Assess Pilot Performance in Upset Recovery

Science.gov (United States)

Le Vie, Lisa R.

2016-01-01

Accidents attributable to in-flight loss of control are the primary cause for fatal commercial jet accidents worldwide. The National Aeronautics and Space Administration (NASA) conducted a literature review to determine and identify the quantitative standards for assessing upset recovery performance. This review contains current recovery procedures for both military and commercial aviation and includes the metrics researchers use to assess aircraft recovery performance. Metrics include time to first input, recognition time and recovery time and whether that input was correct or incorrect. Other metrics included are: the state of the autopilot and autothrottle, control wheel/sidestick movement resulting in pitch and roll, and inputs to the throttle and rudder. In addition, airplane state measures, such as roll reversals, altitude loss/gain, maximum vertical speed, maximum/minimum air speed, maximum bank angle and maximum g loading are reviewed as well.

Talys calculations for evaluation of neutron-induced single-event upset cross sections

International Nuclear Information System (INIS)

Bourselier, Jean-Christophe

2005-08-01

The computer code TALYS has been used to calculate interactions between cosmic-ray neutrons and silicon nuclei with the goal to describe single-event upset (SEU) cross sections in microelectronics devices. Calculations for the Si(n,X) reaction extend over an energy range of 2 to 200 MeV. The obtained energy spectra of the resulting residuals and light-ions have been integrated using several different critical charges as SEU threshold. It is found that the SEU cross section seems largely to be dominated by 28 Si recoils from elastic scattering. Furthermore, the shape of the SEU cross section as a function of the energy of the incoming neutron changes drastically with decreasing critical charge. The results presented in this report stress the importance of performing studies at mono-energetic neutron beams to advance the understanding of the underlying mechanisms causing SEUs

A simple analytical model of single-event upsets in bulk CMOS

Energy Technology Data Exchange (ETDEWEB)

Sogoyan, Armen V.; Chumakov, Alexander I.; Smolin, Anatoly A., E-mail: aasmol@spels.ru; Ulanova, Anastasia V.; Boruzdina, Anna B.

2017-06-01

During the last decade, multiple new methods of single event upset (SEU) rate prediction for aerospace systems have been proposed. Despite different models and approaches being employed in these methods, they all share relatively high usage complexity and require information about a device that is not always available to an end user. This work presents an alternative approach to estimating SEU cross-section as a function of linear energy transfer (LET) that can be further developed into a method of SEU rate prediction. The goal is to propose a simple, yet physics-based, approach with just two parameters that can be used even in situations when only a process node of the device is known. The developed approach is based on geometrical interpretation of SEU cross-section and an analytical solution to the diffusion problem obtained for a simplified IC topology model. A good fit of the model to the experimental data encompassing 7 generations of SRAMs is demonstrated.

A simple analytical model of single-event upsets in bulk CMOS

International Nuclear Information System (INIS)

Sogoyan, Armen V.; Chumakov, Alexander I.; Smolin, Anatoly A.; Ulanova, Anastasia V.; Boruzdina, Anna B.

2017-01-01

During the last decade, multiple new methods of single event upset (SEU) rate prediction for aerospace systems have been proposed. Despite different models and approaches being employed in these methods, they all share relatively high usage complexity and require information about a device that is not always available to an end user. This work presents an alternative approach to estimating SEU cross-section as a function of linear energy transfer (LET) that can be further developed into a method of SEU rate prediction. The goal is to propose a simple, yet physics-based, approach with just two parameters that can be used even in situations when only a process node of the device is known. The developed approach is based on geometrical interpretation of SEU cross-section and an analytical solution to the diffusion problem obtained for a simplified IC topology model. A good fit of the model to the experimental data encompassing 7 generations of SRAMs is demonstrated.

Development of Single-Event Upset hardened programmable logic devices in deep submicron CMOS

International Nuclear Information System (INIS)

Bonacini, S.

2007-11-01

The electronics associated to the particle detectors of the Large Hadron Collider (LHC), under construction at CERN, will operate in a very harsh radiation environment. Commercial Off-The-Shelf (COTS) components cannot be used in the vicinity of particle collision due to their poor radiation tolerance. This thesis is a contribution to the effort to cover the need for radiation-tolerant SEU-robust (Single Event Upset) programmable components for application in high energy physics experiments. Two components are under development: a Programmable Logic Device (PLD) and a Field-Programmable Gate Array (FPGA). The PLD is a fuse-based, 10-input, 8-I/O general architecture device in 0.25 μm CMOS technology. The FPGA under development is a 32*32 logic block array, equivalent to ∼ 25 k gates, in 0.13 μm CMOS. The irradiation test results obtained in the CMOS 0.25 μm technology demonstrate good robustness of the circuit up to an LET (Linear Energy Transfer) of 79.6 cm 2 *MeV/mg, which make it suitable for the target environment. The CMOS 0.13 μm circuit has showed robustness to an LET of 37.4 cm 2 *MeV/mg in the static test mode and has increased sensitivity in the dynamic test mode. This work focused also on the research for an SEU-robust register in both the mentioned technologies. The SEU-robust register is employed as a user data flip-flop in the FPGA and PLD designs and as a configuration cell as well in the FPGA design

Resistance Upset Welding of ODS Steel Fuel Claddings—Evaluation of a Process Parameter Range Based on Metallurgical Observations

Directory of Open Access Journals (Sweden)

Fabien Corpace

2017-08-01

Full Text Available Resistance upset welding is successfully applied to Oxide Dispersion Strengthened (ODS steel fuel cladding. Due to the strong correlation between the mechanical properties and the microstructure of the ODS steel, this study focuses on the consequences of the welding process on the metallurgical state of the PM2000 ODS steel. A range of process parameters is identified to achieve operative welding. Characterizations of the microstructure are correlated to measurements recorded during the welding process. The thinness of the clad is responsible for a thermal unbalance, leading to a higher temperature reached. Its deformation is important and may lead to a lack of joining between the faying surfaces located on the outer part of the join which can be avoided by increasing the dissipated energy or by limiting the clad stick-out. The deformation and the temperature reached trigger a recrystallization phenomenon in the welded area, usually combined with a modification of the yttrium dispersion, i.e., oxide dispersion, which can damage the long-life resistance of the fuel cladding. The process parameters are optimized to limit the deformation of the clad, preventing the compactness defect and the modification of the nanoscale oxide dispersion.

Extension of the TCV Operating Space Towards Higher Elongation and Higher Normalized Current

International Nuclear Information System (INIS)

Hofmann, F.; Coda, S.; Lavanchy, P.; Llobet, X.; Marmillod, Ph.; Martin, Y.; Martynov, A.; Mlynar, J.; Moret, J.-M.; Pochelon, A.; Sauter, O.

2002-01-01

Recently, an experimental campaign has been launched on TCV with the aim of exploring and extending the limits of the operating space. The vertical position control system has been optimized, with the help of extensive model calculations, in order to allow operation at the lowest possible stability margin. In addition, the growth rate of the axisymmetric instability has been minimized by choosing optimum values for the plasma triangularity and squareness and by operating close to the current limit imposed by the n= 1 external kink mode. These measures have allowed us to reach record values of elongation, κ=2.8, and normalized current, I N =3.6, in a tokamak with standard aspect ratio, R/a=3.5. (author)

Interfacing robotics with plutonium fuel fabrication

International Nuclear Information System (INIS)

Bowen, W.W.; Moore, F.W.

1986-01-01

Interfacing robotic systems with nuclear fuel fabrication processes resulted in a number of interfacing challenges. The system not only interfaces with the fuel process, but must also interface with nuclear containment, radiation control boundaries, criticality control restrictions, and numerous other safety systems required in a fuel fabrication plant. The robotic system must be designed to allow operator interface during maintenance and recovery from an upset as well as normal operations

Parameter study on the influence of prepressurization on LWR fuel rod behaviour during normal operation and hypothetical LOCA

International Nuclear Information System (INIS)

Fuchs, H.P.; Brzoska, B.; Depisch, F.; Sauermann, W.

1978-01-01

To analyse the influence of prepressurization on fuel rod behaviour, a parametric study has been performed considering the effects of the as-fabricated fuel rod internal prepressure on the normal operation and postulated LOCA red behaviour of a 1300 MWe1 KWU standard nuclear power plant pressurized water reactor. A reduction of prepressurization in the analysed range results in a negligible worsened normal operation behaviour whereas the LOCA behaviour is improved significantly. (author)

Single event upset in static random access memories in atmospheric neutron environments

CERN Document Server

Arita, Y; Ogawa, I; Kishimoto, T

2003-01-01

Single-event upsets (SEUs) in a 0.4 mu m 4Mbit complementary metal oxide semiconductor (CMOS) static random access memory (SRAM) were investigated in various atmospheric neutron environments at sea level, at an altitude of 2612 m mountain, at an altitude of commercial airplane, and at an underground depth of 476m. Neutron-induced SEUs increase with the increase in altitude. For a device with a borophosphosilicate glass (BPSG) film, SEU rates induced by thermal neutrons increase with the decrease in the cell charge of a memory cell. A thermal neutron-induced SEU is significant in SRAMs with a small cell charge. With the conditions of small cell charge, thermal neutron-induced SEUs account for 60% or more of the total neutron-induced SEUs. The SEU rate induced by atmospheric thermal neutrons can be estimated by an acceleration test using sup 2 sup 5 sup 2 Cf. (author)

FinFET memory cell improvements for higher immunity against single event upsets

Science.gov (United States)

Sajit, Ahmed Sattar

The 21st century is witnessing a tremendous demand for transistors. Life amenities have incorporated the transistor in every aspect of daily life, ranging from toys to rocket science. Day by day, scaling down the transistor is becoming an imperious necessity. However, it is not a straightforward process; instead, it faces overwhelming challenges. Due to these scaling changes, new technologies, such as FinFETs for example, have emerged as alternatives to the conventional bulk-CMOS technology. FinFET has more control over the channel, therefore, leakage current is reduced. FinFET could bridge the gap between silicon devices and non-silicon devices. The semiconductor industry is now incorporating FinFETs in systems and subsystems. For example, Intel has been using them in their newest processors, delivering potential saving powers and increased speeds to memory circuits. Memory sub-systems are considered a vital component in the digital era. In memory, few rows are read or written at a time, while the most rows are static; hence, reducing leakage current increases the performance. However, as a transistor shrinks, it becomes more vulnerable to the effects from radioactive particle strikes. If a particle hits a node in a memory cell, the content might flip; consequently, leading to corrupting stored data. Critical fields, such as medical and aerospace, where there are no second chances and cannot even afford to operate at 99.99% accuracy, has induced me to find a rigid circuit in a radiated working environment. This research focuses on a wide spectrum of memories such as 6T SRAM, 8T SRAM, and DICE memory cells using FinFET technology and finding the best platform in terms of Read and Write delay, susceptibility level of SNM, RSNM, leakage current, energy consumption, and Single Event Upsets (SEUs). This research has shown that the SEU tolerance that 6T and 8T FinFET SRAMs provide may not be acceptable in medical and aerospace applications where there is a very high

Influences of lubricant pocket geometry and working conditions upon micro lubrication mechanisms in upsetting and strip drawing

DEFF Research Database (Denmark)

Shimizu, Ichiro; Martins, P. A. F.; Bay, Niels

2010-01-01

, during upsetting and strip drawing, by means of a rigid-viscoplastic finite-element formulation. Special emphasis is placed on the effect of pocket geometry on the build-up of hydrostatic pressure, which is responsible for the onset of micro-lubrication mechanisms. A good agreement is found between......Micro-lubricant pockets located in the surface of plastically deforming workpieces are recognised to improve the performance of fluid lubrication in a metal-forming process. This work investigates the joint influence of pocket geometry and process working conditions on micro-lubrication mechanisms...

Nuclear data relevant to single event upsets in semiconductor memories induced by cosmic-ray neutrons and protons

International Nuclear Information System (INIS)

Watanabe, Yukinobu

2008-01-01

The role of nuclear data is examined in the study of single event upset (SEU) phenomena in semiconductor memories caused by cosmic-ray neutrons and protons. Neutron and proton SEU cross sections are calculated with a simplified semi-empirical model using experimental heavy-ion SEU cross-sections and a dedicated database of neutron and proton induced reactions on 28 Si. Some impacts of the nuclear reaction data on SEU simulation are analyzed by investigating relative contribution of secondary ions and neutron elastic scattering to SEU and influence of simultaneous multiple ions emission on SEU. (author)

The single event upset environment for avionics at high latitude

International Nuclear Information System (INIS)

Sims, A.J.; Dyer, C.S.; Peerless, C.L.; Farren, J.

1994-01-01

Modern avionic systems for civil and military applications are becoming increasingly reliant upon embedded microprocessors and associated memory devices. The phenomenon of single event upset (SEU) is well known in space systems and designers have generally been careful to use SEU tolerant devices or to implement error detection and correction (EDAC) techniques where appropriate. In the past, avionics designers have had no reason to consider SEU effects but is clear that the more prevalent use of memory devices combined with increasing levels of IC integration will make SEU mitigation an important design consideration for future avionic systems. To this end, it is necessary to work towards producing models of the avionics SEU environment which will permit system designers to choose components and EDAC techniques which are based on predictions of SEU rates correct to much better than an order of magnitude. Measurements of the high latitude SEU environment at avionics altitude have been made on board a commercial airliner. Results are compared with models of primary and secondary cosmic rays and atmospheric neutrons. Ground based SEU tests of static RAMs are used to predict rates in flight

Mathematical model and computer code for coated particles performance at normal operating conditions

International Nuclear Information System (INIS)

Golubev, I.; Kadarmetov, I.; Makarov, V.

2002-01-01

Computer modeling of thermo-mechanical behavior of coated particles during operating both at normal and off-normal conditions has a very significant role particularly on a stage of new reactors development. In Russia a big experience has been accumulated on fabrication and reactor tests of CP and fuel elements with UO 2 kernels. However, this experience cannot be using in full volume for development of a new reactor installation GT-MHR. This is due to very deep burn-up of the fuel based on plutonium oxide (up to 70% fima). Therefore the mathematical modeling of CP thermal-mechanical behavior and failure prediction becomes particularly important. The authors have a clean understanding that serviceability of fuel with high burn-ups are defined not only by thermo-mechanics, but also by structured changes in coating materials, thermodynamics of chemical processes, 'amoeba-effect', formation CO etc. In the report the first steps of development of integrate code for numerical modeling of coated particles behavior and some calculating results concerning the influence of various design parameters on fuel coated particles endurance for GT-MHR normal operating conditions are submitted. A failure model is developed to predict the fraction of TRISO-coated particles. In this model it is assumed that the failure of CP depends not only on probability of SiC-layer fracture but also on the PyC-layers damage. The coated particle is considered as a uniform design. (author)

Occupational radiation exposure at the Eurochemic reprocessing plant during normal operation and intervention periods

International Nuclear Information System (INIS)

Osipenco, A.

1980-01-01

The Eurochemic reprocessing plant is a direct-maintenance, demonstration facility. From 1966 to 1974 it has processed about 180 tonnes of natural or low-enriched uranium, mainly as oxide, and about 30 tonnes of alloys of aluminium and highly enriched uranium. In this period, the operation was stopped for the time necessary to build and connect a new unit for the separation and purification of plutonium. As from 1975, all equipment was rinsed in order to put the plant in standby, some particular equipment was dismantled and a campaign of systematic decontamination was started. Simultaneously, the necessary steps were taken for the solidification and conditioning for storage or disposal of the wastes produced during the operation of the plant. The methods used to determine the individual doses due to external or internal irradiation are shortly described, as well as the rules set up for limiting these doses or for authorizing planned exposures. For the period 1966-1978 the paper shows the distribution of yearly individual and collective doses recorded for the permanent staff and for workers occupied for limited times. Correlations are shown between the absorbed doses and the nature of the work (normal operation, intervention, etc.) or the function in the enterprise (operation, maintenance, health physics, etc.). A small number of incidents leading to intakes or doses higher than normal did occur. However, experience has shown that careful planning and close collaboration between operational and health physics staff have resulted in keeping the doses within the authorized limits. (author)

Single Event Upset Rate Estimates for a 16-K CMOS (Complementary Metal Oxide Semiconductor) SRAM (Static Random Access Memory).

Science.gov (United States)

1986-09-30

4 . ~**..ft.. ft . - - - ft SI TABLES 9 I. SA32~40 Single Event Upset Test, 1140-MeV Krypton, 9/l8/8~4. . .. .. .. .. .. .16 II. CRUP Simulation...cosmic ray interaction analysis described in the remainder of this report were calculated using the CRUP computer code 3 modified for funneling. The... CRUP code requires, as inputs, the size of a depletion region specified as a retangular parallel piped with dimensions a 9 b S c, the effective funnel

Identification of support structure damping of a full scale offshore wind turbine in normal operation

DEFF Research Database (Denmark)

Koukoura, Christina; Natarajan, Anand; Vesth, Allan

2015-01-01

damping from the decaying time series. The Enhanced Frequency Domain Decomposition (EFDD) method was applied to the wind turbine response under ambient excitation, for estimation of the damping in normal operation. The aero-servo-hydro-elastic tool HAWC2 is validated with offshore foundation load...... maxima of an impulse response caused by a boat impact. The result is used in the verification of the non aerodynamic damping in normal operation for low wind speeds. The auto-correlation function technique for damping estimation of a structure under ambient excitation was validated against the identified...... measurements. The model was tuned to the damping values obtained from the boat impact to match the measured loads. Wind turbulence intensity and wave characteristics used in the simulations are based on site measurements. A flexible soil model is included in the analysis. The importance of the correctly...

Pellet cladding interaction (PCI) fuel duty during normal operation of ASEA-ATOM BWRs

International Nuclear Information System (INIS)

Vaernild, O.; Olsson, S.

1983-01-01

Local power changes may under special conditions cause PCI fuel failures in a power reactor. By restricting the local power increase rate in certain situations it is possible to prevent PCI failures. Fine motion control rod drives, large operating range of the main recirculation pumps and an advanced burnable absorber design have minimized the impact of the PCI restrictions. With current ICFM schemes the power of an assembly is due to the burnup of the gadolinia gradually increasing during the first cycle of operation. After this the power is essentially decreasing monotonously during the remaining life of the assembly. Some assemblies are for short burnup intervals operated at very low power in control cells. The control rods in these cells may however be withdrawn without restrictions leading to energy production losses. Base load operation would in the normal case lead to very minor PCI loads on the fuel regardless of any PCI related operating restrictions. At the return to full power after a short shutdown or in connection with load follow operation, the xenon transient may cause PCI loads on the fuel. To avoid this a few hoursholdtime before going back to full power is recommended. (author)

Pellet-cladding interaction (PCI) fuel duty during normal operation of ASEA-ATOM BWRs

International Nuclear Information System (INIS)

Vaernild, O.; Olsson, S.

1985-01-01

Local power changes may, under special conditions, cause PCI fuel failures in a power reactor. By restricting the local power increase rate in certain situations it is possible to prevent PCI failures. Fine motion control rod drives, large operating range of the main recirculation pumps and an advanced burnable absorber design have minimized the impact of the PCI restrictions. With current ICFM schemes the power of an assembly is due to the burnup of the gadolinia gradually increasing during the first cycle of operation. After this the power is essentially decreasing monotonously during the remaining life of the assembly. Some assemblies are for short burnup intervals operated at very low power in control cells. The control rods in these cells may, however, be withdrawn without restrictions leading to energy production losses. Base load operation would in the normal case lead to very minor PCI loads on the fuel regardless of any PCI-related operating restrictions. At the return to full power after a short shutdown or in connection with load follow operation, the xenon transient may cause PCI loads on the fuel. To avoid this a few hours hold-time before going back to full power is recommended. (author)

Nuclear data relevant to single-event upsets (SEU) in microelectronics and their application to SEU simulation

International Nuclear Information System (INIS)

Watanabe, Yukinobu; Tukamoto, Yasuyuki; Kodama, Akihiro; Nakashima, Hideki

2004-01-01

A cross-section database for neutron-induced reactions on 28 Si was developed in the energy range between 2 MeV and 3 GeV in order to analyze single-event upsets (SEUs) phenomena induced by cosmic-ray neutrons in microelectronic devices. A simplified spherical device model was proposed for simulation of the initial process of SEUs. The model was applied to SEU cross-section calculations for semiconductor memory devices. The calculated results were compared with measured SEU cross-sections and the other simulation result. The dependence of SEU cross-sections on incident neutron energy and secondary ions having the most important effects on SEUs are discussed. (author)

Radioactivities evaluation code system for high temperature gas cooled reactors during normal operation

International Nuclear Information System (INIS)

Ogura, Kenji; Morimoto, Toshio; Suzuki, Katsuo.

1979-01-01

A radioactivity evaluation code system for high temperature gas-cooled reactors during normal operation was developed to study the behavior of fission products (FP) in the plants. The system consists of a code for the calculation of diffusion of FPs in fuel (FIPERX), a code for the deposition of FPs in primary cooling system (PLATO), a code for the transfer and emission of FPs in nuclear power plants (FIPPI-2), and a code for the exposure dose due to emitted FPs (FEDOSE). The FIPERX code can calculate the changes in the course of time FP of the distribution of FP concentration, the distribution of FP flow, the distribution of FP partial pressure, and the emission rate of FP into coolant. The amount of deposition of FPs and their distribution in primary cooling system can be evaluated by the PLATO code. The FIPPI-2 code can be used for the estimation of the amount of FPs in nuclear power plants and the amount of emitted FPs from the plants. The exposure dose of residents around nuclear power plants in case of the operation of the plants is calculated by the FEDOSE code. This code evaluates the dose due to the external exposure in the normal operation and in the accident, and the internal dose by the inhalation of radioactive plume and foods. Further studies of this code system by the comparison with the experimental data are considered. (Kato, T.)

The normalized administration of hybrid operating room: its practical application in managing multiple injuries

International Nuclear Information System (INIS)

Li Xue; Zhang Weiguo; Zhang Lianyang; Chen Tingjing; Chen Jinhua

2011-01-01

Objective: Through carrying out the normalized administration of hybrid operating room the application of the operating room is expanded to the performing of multiple injuries, and, in this way, the operative management become standardized and programmed, the cooperation and efficiency of hybrid operations for multiple injuries are improved and the surgeries can be ensured. Methods: According to the characteristics of hybrid interventional operation for multiple injuries, the basic construction of the hybrid operating room improved, the hybrid operation team was organized, and the administrative system as well as the working program were established. The green channel for rescuing patients with multiple injuries was set up. The cooperative behavior during interventional treatment for multiple injuries was specified. Results: The coordination and working efficiency of physicians, nurses, technicians and anesthetists were well improved. The qualified rate of lamina flow administration reached 100%. The success rate of the rescue of multiple injuries was increased. Conclusion: As one-stop complex interventional operation for multiple injuries is a new technique, there is no integrated administration system. Therefore, the establishment of standardized management of one-stop complex interventional operation is of great significance in guiding clinical practice. (authors)

A monitor for the laboratory evaluation of control integrity in digital control systems operating in harsh electromagnetic environments

Science.gov (United States)

Belcastro, Celeste M.; Fischl, Robert; Kam, Moshe

1992-01-01

This paper presents a strategy for dynamically monitoring digital controllers in the laboratory for susceptibility to electromagnetic disturbances that compromise control integrity. The integrity of digital control systems operating in harsh electromagnetic environments can be compromised by upsets caused by induced transient electrical signals. Digital system upset is a functional error mode that involves no component damage, can occur simultaneously in all channels of a redundant control computer, and is software dependent. The motivation for this work is the need to develop tools and techniques that can be used in the laboratory to validate and/or certify critical aircraft controllers operating in electromagnetically adverse environments that result from lightning, high-intensity radiated fields (HIRF), and nuclear electromagnetic pulses (NEMP). The detection strategy presented in this paper provides dynamic monitoring of a given control computer for degraded functional integrity resulting from redundancy management errors, control calculation errors, and control correctness/effectiveness errors. In particular, this paper discusses the use of Kalman filtering, data fusion, and statistical decision theory in monitoring a given digital controller for control calculation errors.

Health effects of technologies for power generation: Contributions from normal operation, severe accidents and terrorist threat

International Nuclear Information System (INIS)

Hirschberg, Stefan; Bauer, Christian; Burgherr, Peter; Cazzoli, Eric; Heck, Thomas; Spada, Matteo; Treyer, Karin

2016-01-01

As a part of comprehensive analysis of current and future energy systems we carried out numerous analyses of health effects of a wide spectrum of electricity supply technologies including advanced ones, operating in various countries under different conditions. The scope of the analysis covers full energy chains, i.e. fossil, nuclear and renewable power plants and the various stages of fuel cycles. State-of-the-art methods are used for the estimation of health effects. This paper addresses health effects in terms of reduced life expectancy in the context of normal operation as well as fatalities resulting from severe accidents and potential terrorist attacks. Based on the numerical results and identified patterns a comparative perspective on health effects associated with various electricity generation technologies and fuel cycles is provided. In particular the estimates of health risks from normal operation can be compared with those resulting from severe accidents and hypothetical terrorist attacks. A novel approach to the analysis of terrorist threat against energy infrastructure was developed, implemented and applied to selected energy facilities in various locations. Finally, major limitations of the current approach are identified and recommendations for further work are given. - Highlights: • We provide state-of-the-art comparative assessment of energy health risks. • The scope of the analysis should to the extent possible cover full energy chains. • Health impacts from normal operation dominate the risks. • We present novel approach to analysis of terrorist threat. • Limitations include technology choices, geographical coverage and terrorist issues.

Irreducible normalizer operators and thresholds for degenerate quantum codes with sublinear distances

Science.gov (United States)

Pryadko, Leonid P.; Dumer, Ilya; Kovalev, Alexey A.

2015-03-01

We construct a lower (existence) bound for the threshold of scalable quantum computation which is applicable to all stabilizer codes, including degenerate quantum codes with sublinear distance scaling. The threshold is based on enumerating irreducible operators in the normalizer of the code, i.e., those that cannot be decomposed into a product of two such operators with non-overlapping support. For quantum LDPC codes with logarithmic or power-law distances, we get threshold values which are parametrically better than the existing analytical bound based on percolation. The new bound also gives a finite threshold when applied to other families of degenerate quantum codes, e.g., the concatenated codes. This research was supported in part by the NSF Grant PHY-1416578 and by the ARO Grant W911NF-11-1-0027.

LHC Beam Dump Design Study - Part III : Off-normal operating conditions

CERN Document Server

Bruno, L; Ross, M; Sala, P

2000-01-01

The LHC beam dump design study has been preliminarily substantiated by energy deposition simulations (Part I) and heat transfer analyses (Part II). The present report is devoted to the abnormal operating conditions induced by a malfunction of the beam diluters. A general approach to the analysis of off-normal operation is presented, which is derived from standard design norms adopted in the nuclear industry. Attention is focused mainly on the carbon core, which is longitudinally split into segments of different density in order to better distribute the deposited energy. The maximum energy density it absorbs decreases by at least 33%, compared to a uniform standard density carbon core. This structure may sustain any partial sweep failure without major damage, up to the ultimate beam intensity and energy. To minimise the risks inherent in a fully unswept beam, a sacrificial graphite mandrel will be placed on the core axis, surrounded by a thick high strength carbon-carbon composite tube. With this arrangement, ...

Thermal loads on tokamak plasma-facing components during normal operation and disruptions

International Nuclear Information System (INIS)

McGrath, R.T.

1990-01-01

Power loadings experienced by tokamak plasma-facing components during normal operation and during off-normal events are discussed. A model for power and particle flow in the tokamak boundary layer is presented and model predictions are compared to infrared measurements of component heating. The inclusion of the full three-dimensional geometry of the components and of the magnetic flux surface is very important in the modeling. Experimental measurements show that misalignment of component armour tile surfaces by only a millimeter can lead to significant localized heating. An application to the design of plasma-facing components for future machines is presented. Finally, thermal loads expected during tokamak disruptions are discussed. The primary problems are surface melting and vaporization due to localized intense heating during the disruption thermal quench and volumetric heating of the component armour and structure due to localised impact of runaway electrons. (author)

EMERALD-NORMAL, Routine Radiation Release and Dose for PWR Design Analysis and Operation Analysis

International Nuclear Information System (INIS)

Gillespie, S.G.; Brunot, W.K.

1976-01-01

1 - Description of problem or function: EMERALD-NORMAL is designed for the calculation of radiation releases and exposures resulting from normal operation of a large pressurized water reactor. The approach used is similar to an analog simulation of a real system. Each component or volume in the plant which contains a radioactive material is represented by a subroutine which keeps track of the production, transfer, decay, and absorption of radioactivity in that volume. During the course of the analysis, activity is transferred from subroutine to subroutine in the program as it would be transferred from place to place in the plant. Some of this activity is then released to the atmosphere and to the discharge canal. The rates of transfer, leakage, production, cleanup, decay, and release are read as input to the program. Subroutines are also included which calculate the off-site radiation exposures at various distances for individual isotopes and sums of isotopes. The program contains a library of physical data for the forty isotopes of most interest in licensing calculations, and other isotopes can be added or substituted. Because of the flexible nature of the simulation approach, the EMERALD-NORMAL program can be used for most calculations involving the production and release of radioactive material. These include design, operation, and licensing studies. 2 - Method of solution: Explicit solutions of first-order linear differential equations are included. In addition, a subroutine is provided which solves a set of simultaneous linear algebraic equations. 3 - Restrictions on the complexity of the problem: Many parameters and systems included in the program, particularly the radiation waste-treatment system, are unique to the PG and E Diablo Canyon PWR plant. Maxima of: 50 isotopes, 9 distances, 16 angular sectors, 1 operating period, 1 reactor power level

Effects of Cabin Upsets on Adsorption Columns for Air Revitalization

Science.gov (United States)

LeVan, Douglas

1999-01-01

The National Aeronautics and Space Administration (NASA) utilizes adsorption technology as part of contaminant removal systems designed for long term missions. A variety of trace contaminants can be effectively removed from gas streams by adsorption onto activated carbon. An activated carbon adsorption column meets NASA's requirements of a lightweight and efficient means of controlling trace contaminant levels aboard spacecraft and space stations. The activated carbon bed is part of the Trace Contaminant Control System (TCCS) which is utilized to purify the cabin atmosphere. TCCS designs oversize the adsorption columns to account for irregular fluctuations in cabin atmospheric conditions. Variations in the cabin atmosphere include changes in contaminant concentrations, temperature, and relative humidity. Excessively large deviations from typical conditions can result from unusual crew activity, equipment malfunctions, or even fires. The research carried out under this award focussed in detail on the effects of cabin upsets on the performance of activated carbon adsorption columns. Both experiments and modeling were performed with an emphasis on the roll of a change in relative humidity on adsorption of trace contaminants. A flow through fixed-bed apparatus was constructed at the NASA Ames Research Center, and experiments were performed there. Modeling work was performed at the University of Virginia.

AECB staff review of Bruce NGS 'B' operation for the year 1989

International Nuclear Information System (INIS)

1990-06-01

The operation of the Bruce Nuclear Generating Station 'B' is monitored and licensing requirements are enforced by the Atomic Energy Control Board (AECB), which observes operation of the reactors, conducts audits, witnesses important activities, reviews station documentation and reports, and issue approvals, where appropriate, in accordance with licence conditions. This report records the conclusions of the AECB staff assessment of Bruce NGS 'B' during 1989. In general, the station operated within acceptable safety standards. Quality improvement initiatives started in 1989 should lead to improved station maintenance and operation in coming years. Ontario Hydro still needs to improve the administration of operating memos, deficiency reports and call-ups. Station management must ensure that shift supervisors and reactor first operators operate the station in a conservative manner at all times and put safety interests first when responding to a unit upset. (2 tabs.)

Single event upset mitigation techniques for FPGAs utilized in nuclear power plant digital instrumentation and control

International Nuclear Information System (INIS)

Wang Xin; Holbert, Keith E.; Clark, Lawrence T.

2011-01-01

Highlights: → Triple modular redundancy (TMR) implementation is the best solution for digital I and C. → Maximal probability of two simultaneous errors with TMR maximum partition is 4.44%. → Dual modular redundancy minimum logic partitioning design is an additional option. - Abstract: Field programmable gate arrays (FPGAs) are integrated circuits being increasingly used for digital instrumentation and control (I and C) in nuclear power plants (NPPs) because of low cost, re-configurability and low design turn-around time. However, to ensure reliability, proper design techniques must be employed since the memory and logic in FPGAs are susceptible to single event upsets (SEUs). Triple modular redundancy (TMR) has become a common SEU mitigation design technique because of its straightforward implementation and reliable results. Partitioned TMR approaches are introduced in this paper, and formulae derived indicate that the maximum probability of two simultaneous errors [P E ] max is inversely proportional to the number of logic partitions in a TMR design, when each redundant logic block in every logic partition has the same number of sensitive nodes. However, the maximum logic partitioning design cannot completely eliminate the possibility of two simultaneous upsets. For the example test circuit it is found that [P E ] max is reduced dramatically from 66.67% for minimum logic partitioning to 4.44% for maximum logic partitioning. Because TMR introduces significant overhead due to its full hardware redundancy, a dual modular redundancy approach is also examined for application to less demanding situations. By comparative analysis this study reaches the conclusion that the maximum logic partitioning TMR implementation is the best solution for digital I and C applications in NPPs where obtaining robustness is of the highest importance, despite its higher area overhead.

Simulation of zincblende AlGaN/GaN high electron mobility transistors for normally-off operation

Science.gov (United States)

Grady, R.; Bayram, C.

2017-07-01

In this work we investigate design parameters enabling normally-off operation of zincblende (ZB-) phase Al X Ga(1-X)N/GaN high electron mobility transistors (HEMTs) via Synopsys Sentaurus Technology Computer Aided Design (TCAD). As ZB-phase III-nitrides are polarization-free, the 2D electron gas (2DEG) channel at the Al X Ga(1-X)N/GaN heterojunction is formed through intentional δ-doping part of the Al X Ga(1-X)N barrier layer. The impact of each of the design parameters (i.e. Al-content and thickness of Al X Ga(1-X)N barrier; δ-doping location (within the Al X Ga(1-X)N barrier), δ-doped Al X Ga(1-X)N layer thickness and its doping amount; gate metal) are studied in detail and design trade-offs are reported. We show that work function of the gate metal impacts normally-off behavior and turn-on voltage considerably. Our results suggest that Al-content of 35% or less in the Al X Ga(1-X)N barrier results in a normally-off behavior whereas Al X Ga(1-X)N barrier thickness is effective in controlling the turn-on voltage. Overall, we provide design guidelines in controlling the normally-on/-off operation, threshold voltage, and 2DEG density in ZB-phase AlGaN/GaN HEMT technology.

Investigation of radial dose effect on single event upset cross-section due to heavy ions using GEANT4

International Nuclear Information System (INIS)

Boorboor, S.; Feghhi, S.A.H.; Jafari, H.

2015-01-01

The heavy ions are the main cause to produce single event upset (SEU) damage on electronic devices since they are high LET radiations. The dimension of electronic components in new technology, arise a challenge in radiation effect estimations. Accurate investigations require fully considering the ion track in energy deposition as a radial dose distribution. In this work, the distribution of delta rays as well as LET have been calculated to determine ionization structure around ion track by a Monte Carlo code, GEANT4. The radial dose of several heavy ions with different energy in silicon was investigated and compared with the works by other authors in this field. The results showed that heavy ions with identical LET can have different SEU cross-section in silicon transistors. As a demonstrative example, according to our results, the error probability for 4.8 GeV iron was 8 times greater than that for 15 MeV carbon ions, in transistors with new process technology which have small dimension and low critical charges. Our results show that considering radial dose distribution considerably improves the accuracy of the SEU cross-section estimation in electronic devices especially for new technologies. - Highlights: • The single event upset is produced by heavy ions interaction on electronic devices. • The radial dose of several heavy ions in silicon was calculated by GEANT4. • Heavy ions with identical LET had different SEU cross-section in silicon transistors. • Low dimension and critical charge devices were more sensitive to radial dose effect

Texture evolution in upset-forged P/M and wrought tantalum: Experimentation and modeling

International Nuclear Information System (INIS)

Bingert, J.F.; Desch, P.B.; Bingert, S.R.; Maudlin, P.J.; Tome, C.N.

1997-11-01

Preferred orientations in polycrystalline materials can significantly affect their physical and mechanical response through the retention of anisotropic properties inherent to the single crystal. In this study the texture evolution in upset-forged PIM and wrought tantalum was measured as a function of initial texture, compressive strain, and relative position in the pressing. A / duplex fiber texture parallel to the compression axis was generally observed, with varying degrees of a radial component evident in the wrought material. The development of deformation textures derives from restricted crystallographic slip conditions that generate lattice rotations, and these grain reorientations can be modeled as a function of the prescribed deformation gradient. Texture development was simulated for equivalent deformations using both a modified Taylor approach and a viscoplastic self-consistent (VPSC) model. A comparison between the predicted evolution and experimental results shows a good correlation with the texture components, but an overly sharp prediction at large strains from both the Taylor and VPSC models

Synergistic effects of total ionizing dose on single event upset sensitivity in static random access memory under proton irradiation

International Nuclear Information System (INIS)

Xiao Yao; Guo Hong-Xia; Zhang Feng-Qi; Zhao Wen; Wang Yan-Ping; Zhang Ke-Ying; Ding Li-Li; Luo Yin-Hong; Wang Yuan-Ming; Fan Xue

2014-01-01

Synergistic effects of the total ionizing dose (TID) on the single event upset (SEU) sensitivity in static random access memories (SRAMs) were studied by using protons. The total dose was cumulated with high flux protons during the TID exposure, and the SEU cross section was tested with low flux protons at several cumulated dose steps. Because of the radiation-induced off-state leakage current increase of the CMOS transistors, the noise margin became asymmetric and the memory imprint effect was observed. (interdisciplinary physics and related areas of science and technology)

Study on B-10 consumption of PWR primary coolant during normal operation

International Nuclear Information System (INIS)

Liang, C.H.

1994-01-01

B-10 consumption under PWR primary coolant conditions has been analyzed. The result indicates its time-dependent change reacting with neutron in the normal operation. In this work, neutron energy assumed to be 4 eV; thermal neutron flux is in the range of 3 x 10 13 to 3 x 10 14 n/sec - cm 2 and the time of cycling of the primary coolant through the RCS is 8 sec. and its retention time in the core region is about 1 sec. Under this condition investigated, B-10 consumption is less than 5% at 3 x 10 13 n/sec - cm 2 thermal neutron flux, and closes to 27% at 3 x 10 14 n/sec - cm 2 by calculation at the 16th month of continuous operation. The effect of B-10 consumption on PWR primary water chemistry is also investigated. (author). 1 fig., 2 tabs., 4 refs

Simulation of zincblende AlGaN/GaN high electron mobility transistors for normally-off operation

International Nuclear Information System (INIS)

Grady, R; Bayram, C

2017-01-01

In this work we investigate design parameters enabling normally-off operation of zincblende (ZB-) phase Al X Ga (1−X) N/GaN high electron mobility transistors (HEMTs) via Synopsys Sentaurus Technology Computer Aided Design (TCAD). As ZB-phase III-nitrides are polarization-free, the 2D electron gas (2DEG) channel at the Al X Ga (1−X) N/GaN heterojunction is formed through intentional δ -doping part of the Al X Ga (1−X) N barrier layer. The impact of each of the design parameters (i.e. Al-content and thickness of Al X Ga (1−X) N barrier; δ -doping location (within the Al X Ga (1−X) N barrier), δ-doped Al X Ga (1−X) N layer thickness and its doping amount; gate metal) are studied in detail and design trade-offs are reported. We show that work function of the gate metal impacts normally-off behavior and turn-on voltage considerably. Our results suggest that Al-content of 35% or less in the Al X Ga (1−X) N barrier results in a normally-off behavior whereas Al X Ga (1−X) N barrier thickness is effective in controlling the turn-on voltage. Overall, we provide design guidelines in controlling the normally-on/-off operation, threshold voltage, and 2DEG density in ZB-phase AlGaN/GaN HEMT technology. (paper)

Evaluation of thermal margin for HANARO core

Energy Technology Data Exchange (ETDEWEB)

Park, Cheol; Chae, Hee Taek; Kim Heon Il; Lim, I. C.; Lee, C. S.; Kim, H

1999-08-01

During the commissioning and the start-up of the HANARO, various design parameters were confirmed and measured. For safer operation of HANARO and resolution of the CHF penalty issue which is one of unresolved licensing problems, thermal margins for normal and transient conditions were re-evaluated reflecting the commissioning and the start-up test results and the design modifications during operation. The re-evaluation shows that the HANARO meets the design criteria for ONB margin and fuel centerline temperature under normal condition. For upset condition, it also satisfies the safety limits for CHFR and fuel centerline temperature. (Author). 11 refs., 13 tabs., 4 figs.

Evolution of microstructure and texture in copper during repetitive extrusion-upsetting and subsequent annealing

DEFF Research Database (Denmark)

Chen, Q.; Shu, D. Y.; Lin, J.

2017-01-01

The evolution of the microstructure and texture in copper has been studied during repetitive extrusion-upsetting (REU) to a total von Mises strain of 4.7 and during subsequent annealing at different temperatures. It is found that the texture is significantly altered by each deformation pass...... strain of 4.7 is measured to be ∼0.3μm. This refined microstructure is unstable at room temperature as is evident from the presence of a small number of recrystallized grains in the deformed matrix. Pronounced recrystallization took place during annealing at 200 °C for 1 h with recrystallized grains...... developing predominantly in high misorientation regions. At 350 ºC the microstructure is fully recrystallized with an average grain size of only 2.3 μm and a very weak crystallographic texture. This REU-processed and subsequently annealed material is considered to be potentially suitable for using...

Evaluation of single-event upset tolerance on 64Mbit DRAM and 16Mbit DRAM

Energy Technology Data Exchange (ETDEWEB)

Nemoto, N; Shindou, H; Matsuzaki, K; Akutsu, T; Matsuda, S [National Space Development Agency of Japan, Tokyo (Japan); Hirao, T; Itoh, H; Nashiyama, I

1997-11-01

In recent years, reduction in the mission cost is regarded as one of the most important matters, and thus much effort has been made to reduce the cost of electronic components used in spacecrafts without diminishing their performance. On this policy, there has been a growing interest in space application of commercial devices such as highly integrated memory ICs because of low prices and high performance of such devices. To ensure success in this application, it is indispensable to investigate radiation effects, e.g., single-event and total-dose effects, on commercial devices precisely. In the present study, we have evaluated single-event upset (SEU) tolerance for 1Mbit, 4Mbit SRAM and 16Mbit, 64Mbit DRAM by irradiation of high energy heavy ions such as 175MeV-Ar{sup 8+} and 450MeV-Xe{sup 23+}. We observed these SEU tolerance in space. (author)

Notice of Violation of IEEE Publication PrinciplesJoint Redundant Residue Number Systems and Module Isolation for Mitigating Single Event Multiple Bit Upsets in Datapath

Science.gov (United States)

Li, Lei; Hu, Jianhao

2010-12-01

Notice of Violation of IEEE Publication Principles"Joint Redundant Residue Number Systems and Module Isolation for Mitigating Single Event Multiple Bit Upsets in Datapath"by Lei Li and Jianhao Hu,in the IEEE Transactions on Nuclear Science, vol.57, no.6, Dec. 2010, pp. 3779-3786After careful and considered review of the content and authorship of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE's Publication Principles.This paper contains substantial duplication of original text from the paper cited below. The original text was copied without attribution (including appropriate references to the original author(s) and/or paper title) and without permission.Due to the nature of this violation, reasonable effort should be made to remove all past references to this paper, and future references should be made to the following articles:"Multiple Error Detection and Correction Based on Redundant Residue Number Systems"by Vik Tor Goh and M.U. Siddiqi,in the IEEE Transactions on Communications, vol.56, no.3, March 2008, pp.325-330"A Coding Theory Approach to Error Control in Redundant Residue Number Systems. I: Theory and Single Error Correction"by H. Krishna, K-Y. Lin, and J-D. Sun, in the IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, vol.39, no.1, Jan 1992, pp.8-17In this paper, we propose a joint scheme which combines redundant residue number systems (RRNS) with module isolation (MI) for mitigating single event multiple bit upsets (SEMBUs) in datapath. The proposed hardening scheme employs redundant residues to improve the fault tolerance for datapath and module spacings to guarantee that SEMBUs caused by charge sharing do not propagate among the operation channels of different moduli. The features of RRNS, such as independence, parallel and error correction, are exploited to establish the radiation hardening architecture for the datapath in radiation environments. In the proposed

Computer Simulation of Complex Power System Faults under various Operating Conditions

International Nuclear Information System (INIS)

Khandelwal, Tanuj; Bowman, Mark

2015-01-01

A power system is normally treated as a balanced symmetrical three-phase network. When a fault occurs, the symmetry is normally upset, resulting in unbalanced currents and voltages appearing in the network. For the correct application of protection equipment, it is essential to know the fault current distribution throughout the system and the voltages in different parts of the system due to the fault. There may be situations where protection engineers have to analyze faults that are more complex than simple shunt faults. One type of complex fault is an open phase condition that can result from a fallen conductor or failure of a breaker pole. In the former case, the condition is often accompanied by a fault detectable with normal relaying. In the latter case, the condition may be undetected by standard line relaying. The effect on a generator is dependent on the location of the open phase and the load level. If an open phase occurs between the generator terminals and the high-voltage side of the GSU in the switchyard, and the generator is at full load, damaging negative sequence current can be generated. However, for the same operating condition, an open conductor at the incoming transmission lines located in the switchyard can result in minimal negative sequence current. In 2012, a nuclear power generating station (NPGS) suffered series or open phase fault due to insulator mechanical failure in the 345 kV switchyard. This resulted in both reactor units tripping offline in two separate incidents. Series fault on one of the phases resulted in voltage imbalance that was not detected by the degraded voltage relays. These under-voltage relays did not initiate a start signal to the emergency diesel generators (EDG) because they sensed adequate voltage on the remaining phases exposing a design vulnerability. This paper is intended to help protection engineers calculate complex circuit faults like open phase condition using computer program. The impact of this type of

Normalized modes at selected points without normalization

Science.gov (United States)

Kausel, Eduardo

2018-04-01

As every textbook on linear algebra demonstrates, the eigenvectors for the general eigenvalue problem | K - λM | = 0 involving two real, symmetric, positive definite matrices K , M satisfy some well-defined orthogonality conditions. Equally well-known is the fact that those eigenvectors can be normalized so that their modal mass μ =ϕT Mϕ is unity: it suffices to divide each unscaled mode by the square root of the modal mass. Thus, the normalization is the result of an explicit calculation applied to the modes after they were obtained by some means. However, we show herein that the normalized modes are not merely convenient forms of scaling, but that they are actually intrinsic properties of the pair of matrices K , M, that is, the matrices already "know" about normalization even before the modes have been obtained. This means that we can obtain individual components of the normalized modes directly from the eigenvalue problem, and without needing to obtain either all of the modes or for that matter, any one complete mode. These results are achieved by means of the residue theorem of operational calculus, a finding that is rather remarkable inasmuch as the residues themselves do not make use of any orthogonality conditions or normalization in the first place. It appears that this obscure property connecting the general eigenvalue problem of modal analysis with the residue theorem of operational calculus may have been overlooked up until now, but which has in turn interesting theoretical implications.Á

Knowledge-enhanced network simulation modeling of the nuclear power plant operator

International Nuclear Information System (INIS)

Schryver, J.C.; Palko, L.E.

1988-01-01

Simulation models of the human operator of advanced control systems must provide an adequate account of the cognitive processes required to control these systems. The Integrated Reactor Operator/System (INTEROPS) prototype model was developed at Oak Ridge National Laboratory (ORNL) to demonstrate the feasibility of dynamically integrating a cognitive operator model and a continuous plant process model (ARIES-P) to provide predictions of the total response of a nuclear power plant during upset/emergency conditions. The model consists of a SAINT network of cognitive tasks enhanced with expertise provided by a knowledge-based fault diagnosis model. The INTEROPS prototype has been implemented in both closed and open loop modes. The prototype model is shown to be cognitively relevant by accounting for cognitive tunneling, confirmation bias, evidence chunking, intentional error, and forgetting

Radioactive airborne effluents and the environmental impact assessment of CAP1400 nuclear power plant under normal operation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Qiong; Guo, RuiPing; Zhang, ChunMing; Chen, XiaoQiu; Wang, Bo, E-mail: wangbo@chinansc.cn

2014-12-15

Highlights: • Typical radionuclides dispersion from CAP1400 under normal operation was simulated. • Modified Gaussian model considered radioactive decay, dry and wet deposition and so on. • The radioactive impact pathways on the public through atmosphere were compared. • The maximum individual effective dose was lower than the public irradiation limit. - Abstract: China Advanced Passive nuclear power plant with installed capacity reaching to 1400 MW (CAP1400) is independently designed as the China's state-of-the-art third generation nuclear power brand based on AP1000 technology digestion and absorption. The concentration of typical radionuclides dispersed from CAP1400 under normal operation was calculated with modified Gaussian model, considering mixed layer height, dry deposition, wet deposition, radioactive decay and so on. The atmospheric dispersion factors, ground deposition rate, individual dose and public dose were also investigated to estimate the radioactive effects of CAP1400 under normal operation on surrounding environment and human beings. The radioactive impact pathways on the public through atmosphere, such as immersion irradiation in the smoke plume, internal irradiation from ingestion and inhalation and external irradiation from surface deposition were briefly introduced with focus on the comparison of the maximum individual effective dose to different group from atmospheric dispersion. All computation results show that the maximum individual irradiation dose happened to children with total effective irradiation dose of 4.52E−03 mSv/y, which was lower than the public irradiation limit of 0.25 mSv/y.

Radioactive airborne effluents and the environmental impact assessment of CAP1400 nuclear power plant under normal operation

International Nuclear Information System (INIS)

Zhang, Qiong; Guo, RuiPing; Zhang, ChunMing; Chen, XiaoQiu; Wang, Bo

2014-01-01

Highlights: • Typical radionuclides dispersion from CAP1400 under normal operation was simulated. • Modified Gaussian model considered radioactive decay, dry and wet deposition and so on. • The radioactive impact pathways on the public through atmosphere were compared. • The maximum individual effective dose was lower than the public irradiation limit. - Abstract: China Advanced Passive nuclear power plant with installed capacity reaching to 1400 MW (CAP1400) is independently designed as the China's state-of-the-art third generation nuclear power brand based on AP1000 technology digestion and absorption. The concentration of typical radionuclides dispersed from CAP1400 under normal operation was calculated with modified Gaussian model, considering mixed layer height, dry deposition, wet deposition, radioactive decay and so on. The atmospheric dispersion factors, ground deposition rate, individual dose and public dose were also investigated to estimate the radioactive effects of CAP1400 under normal operation on surrounding environment and human beings. The radioactive impact pathways on the public through atmosphere, such as immersion irradiation in the smoke plume, internal irradiation from ingestion and inhalation and external irradiation from surface deposition were briefly introduced with focus on the comparison of the maximum individual effective dose to different group from atmospheric dispersion. All computation results show that the maximum individual irradiation dose happened to children with total effective irradiation dose of 4.52E−03 mSv/y, which was lower than the public irradiation limit of 0.25 mSv/y

Study on relations between heavy ions single event upset cross sections and γ accumulated doses

International Nuclear Information System (INIS)

He Chaohui; Geng Bin; Wang Yanping; Peng Honglun; Yang Hailiang; Chen Xiaohua; Li Guozheng

2002-01-01

Experiments were done under 252 Cf and 60 Co γ source to study the relation between heavy ion Single Event Upset (SEU) cross sections and γ accumulated doses. There was no obvious rule and little influence of γ accumulated doses on SEU cross sections when Static Random Access Memories were in power off mode and static power on mode. In active measuring mode, the SEU cross section increased as the accumulated doses increasing when same data were written in memory cells. If reverse data, such as '55' and 'AA', were written in memory cells during the experiment, the SEU cross sections decreased to the level when memories were not irradiated under 60 Co γ source, even more small. It implied that the influence of γ accumulated doses on SEU cross sections can be set off by this method

New layout concepts in MW-scale IGBT modules for higher robustness during normal and abnormal operations

DEFF Research Database (Denmark)

Reigosa, Paula Diaz; Iannuzzo, Francesco; Munk-Nielsen, Stig

2016-01-01

the Finite-Element-Method AnSYS Q3D Extractor, electromagnetic simulations are conducted to extract the self and mutual inductance from the six different layouts. PSpice simulations are used to reveal that the stray parameters inside the module play an important role under normal and abnormal operations...

Microbeam mapping of single event latchups and single event upsets in CMOS SRAMs

International Nuclear Information System (INIS)

Barak, J.; Adler, E.; Fischer, B.E.; Schloegl, M.; Metzger, S.

1998-01-01

The first simultaneous microbeam mapping of single event upset (SEU) and latchup (SEL) in the CMOS RAM HM65162 is presented. The authors found that the shapes of the sensitive areas depend on V DD , on the ions being used and on the site on the chip being hit by the ion. In particular, they found SEL sensitive sites close to the main power supply lines between the memory-bit-arrays by detecting the accompanying current surge. All these SELs were also accompanied by bit-flips elsewhere in the memory (which they call indirect SEUs in contrast to the well known SEUs induced in the hit memory cell only). When identical SEL sensitive sites were hit farther away from the supply lines only indirect SEL sensitive sites could be detected. They interpret these events as latent latchups in contrast to the classical ones detected by their induced current surge. These latent SELs were probably decoupled from the main supply lines by the high resistivity of the local supply lines

Analysis of WWER-440 fuel performance under normal operating conditions

Energy Technology Data Exchange (ETDEWEB)

Gunduz, Oe; Koese, S; Akbas, T [Atomenerjisi Komisyonu, Ankara (Turkey); Colak, Ue [Ankara Nuclear Research and Training Center (Turkey)

1994-12-31

FRAPCON-2 code originally developed for LWR fuel behaviour simulation is used to analyse the WWER-440 fuel rod behaviour at normal operational conditions. The code is capable of utilizing different models for mechanical analysis and gas release calculations. Heat transfer calculations are accomplished through a collocation technique by the method of weighted residuals. Temperature and burnup element properties are evaluated using MATPRO package. As the material properties of Zr-1%Nb used as cladding in WWER-440s are not provided in the code, Zircaloy-4 is used as a substitute for Zr-1%Nb. Mac-Donald-Weisman model is used for gas release calculation. FRACAS-1 and FRACAS-2 models are used in the mechanical calculations. It is assumed that the reactor was operated for 920 days (three consecutive cycles), the burnup being 42000 Mwd/t U. Results of the fuel rod behaviour analysis are given for three axial nodes: bottom node, central node and top node. The variations of the following characteristic fuel rod parameters are studied through the prescribed power history: unmoved gap thickness, gap heat transfer coefficient, fuel axial elongation, cladding axial elongation, fuel centerline temperature and ZrO-thickness at cladding surface. The value of each parameter is calculated as a function of the effective power days for the three nodes by using FRACAS-1 and FRACAS-2 codes for comparison.The results show that calculations with deformable pellet approximation with FRACAS-II model could provide better information for the behaviour of a typical fuel rod. Calculations indicate that fuel rod failure is not observed during the operation. All fuel rod parameters investigated are found to be within the safety limits. It is concluded, however, that for better assessment of reactor safety these calculations should be extended for transient conditions such as LOCA. 1 tab., 10 figs., 4 refs.

Environmental dose-assessment methods for normal operations at DOE nuclear sites

International Nuclear Information System (INIS)

Strenge, D.L.; Kennedy, W.E. Jr.; Corley, J.P.

1982-09-01

Methods for assessing public exposure to radiation from normal operations at DOE facilities are reviewed in this report. The report includes a discussion of environmental doses to be calculated, a review of currently available environmental pathway models and a set of recommended models for use when environmental pathway modeling is necessary. Currently available models reviewed include those used by DOE contractors, the Environmental Protection Agency (EPA), the Nuclear Regulatory Commission (NRC), and other organizations involved in environmental assessments. General modeling areas considered for routine releases are atmospheric transport, airborne pathways, waterborne pathways, direct exposure to penetrating radiation, and internal dosimetry. The pathway models discussed in this report are applicable to long-term (annual) uniform releases to the environment: they do not apply to acute releases resulting from accidents or emergency situations

Proposal for a new normalization reference in LCA based on “safe operating space”: presentation of framework and global factors at midpoint level

DEFF Research Database (Denmark)

Bjørn, Anders; Hauschild, Michael Zwicky

Planetary boundaries have been suggested for a range of environmental impacts,such as climate change, eutrophying nutrients and land use. The boundaries demarcate the safe operating space of humanity: Staying within the space ensures environmental sustainability, while exceeding it risks pushing...... ecosystems into alternative regimes, leading to adverse effects for humanity. Planetary boundaries can be applied as policy targets. To promote a societal development in the direction of these targets, an indicator system is needed that measures the fraction of the safe operating space that a given activity...... normalization factors in units compatible with characterized results at midpoint level in LCA. Our suggested framework allows expressing normalized results in units of “sustainable person years”. Normalization factors are derived by dividing the safe operating space by the global population. The proposed...

Molecular monitoring of equine joint homeostasis

OpenAIRE

de Grauw, J.C.

2010-01-01

Chronic joint disorders are a major cause of impaired mobility and loss of quality of life in both humans and horses. Regardless of the primary insult, any joint disorder is characterized by an upset in normal joint homeostasis, the balance between tissue anabolism and catabolism that is normally maintained by resident articular cells. This upset is often fuelled by a local inflammatory response in the synovial membrane and the articular cartilage. Our current understanding of the pathogenesi...

Psychosocial work strain of maintenance personnel during annual outage and normal operation in a nuclear power plant

International Nuclear Information System (INIS)

Jacobsson, L.; Svensson, O.

1991-01-01

This paper reports on a study which evaluates psychosocial work demands during the annual outage for a maintenance work group in a nuclear power plant. The study is based on a stress paradigm and it has been asserted that increased work strain would have a negative effect on performance. Nineteen workers, aged 20-55 years, participated in the study. The subjects filled out a questionnaire comparing work strain during annual outage and normal operation. During the outage period a 3-shift 24-hour work schedule, including nightwork, was used (working hours during normal operation was 7-16). Increased demands on concentration and vigilance, increased time pressure and strain on social relations within the group were found to characterize work during annual outage. Interestingly, for specific work tasks an association was found between the risk of making errors and high psychological workload. Increased work strain, shiftwork including nightwork and reduced social support are important psychosocial risk factors that might contribute to human error during the outage period

FFTF fuel pin design bases and performance

International Nuclear Information System (INIS)

Cox, C.M.; Hanson, J.E.; Roake, W.E.; Slember, R.J.; Weber, C.E.; Millunzi, A.C.

1975-04-01

The FFTF fuel pin was conservatively designed to meet thermal and structural performance requirements in the categories normal operation, upset events, emergency events, and hypothetical, faulted events. The fuel pin operating limits consistent with these requirements were developed from a strong fuel pin irradiation testing program scoped to define the performance capability under relevant steady state and transient conditions. Comparison of the results of the irradiation testing program with design requirements indicates that the FFTF fuel pin can exceed its goal burnup of 80,000 MWd/MTM. (U.S.)

Plant control impact on IFR power plant passive safety response

International Nuclear Information System (INIS)

Vilim, R.B.

1993-01-01

A method is described for optimizing the closed-loop plant control strategy with respect to safety margins sustained in the unprotected upset response of a liquid metal reactor. The optimization is performed subject to the normal requirements for reactor startup, load change and compensation for reactivity changes over the cycle. The method provides a formal approach to the process of exploiting the innate self-regulating property of a metal fueled reactor to make it less dependent on operator action and less vulnerable to automatic control system fault and/or operator error

Comparison of Pre-operative Central Corneal Thickness in Pediatric Cataract Cases versus Normal

International Nuclear Information System (INIS)

Khan, S.; Ali, M.; Zaheer, N.

2014-01-01

Objective: To compare the pre-operative central corneal thickness (CCT) in paediatric cataract patients with reference to normal control group. Study Design: A case control study. Place and Duration of Study: Paediatric Ophthalmology Clinic of Al-Shifa Trust Eye Hospital (ASTEH), Rawalpindi, from November 2009 to May 2010. Methodology: The study included 116 subjects with equal number of cases and controls. Demographic profile of all the subjects was noted followed by history and detailed ophthalmic examination. CCT was measured using an ultrasonic pachymeter (model Pac Scan 300). The mean of three measurements from the central cornea were recorded in microns. Results were analyzed using SPSS version 17.0. Results: Mean CCT values of the cases was 566.83 +- 37.646 microns while the control group had a mean CCT of 535.81 +- 24.466 microns. Difference between the CCT values of the two groups was highly significant (p < 0.001). Conclusion: Eyes with congenital cataracts have greater CCT values as compared to normal paediatric population. This factor must be kept in mind while interpreting intra-ocular pressure in such patients. (author)

Computation of fission product distribution in core and primary circuit of a high temperature reactor during normal operation

International Nuclear Information System (INIS)

Mattke, U.H.

1991-08-01

The fission product release during normal operation from the core of a high temperature reactor is well known to be very low. A HTR-Modul-reactor with a reduced power of 170 MW th is examined under the aspect whether the contamination with Cs-137 as most important nuclide will be so low that a helium turbine in the primary circuit is possible. The program SPTRAN is the tool for the computations and siumlations of fission product transport in HTRs. The program initially developed for computations of accident events has been enlarged for computing the fission product transport under the conditions of normal operation. The theoretical basis, the used programs and data basis are presented followed by the results of the computations. These results are explained and discussed; moreover the consequences and future possibilities of development are shown. (orig./HP) [de

Cooling system of the core of a nuclear reactor while it is being stopped or normally operating

International Nuclear Information System (INIS)

Tilliette, Z.

1986-01-01

The present invention proposes a cooling system with intermediate gas flow which ensures the reactor core cooling when the primary pumps are stopped either directly by means of main heat-exchange circuits ensuring normally the reactor operation, or by means of separated loops, these ones being able so to operate in an autonomous way for they produce their own electricity needs and also an excedent which is added to the power plant production. The cooling circuit and the heat exchanger are described in detail [fr

Simulator platform for fast reactor operation and safety technology demonstration

International Nuclear Information System (INIS)

Vilim, R.B.; Park, Y.S.; Grandy, C.; Belch, H.; Dworzanski, P.; Misterka, J.

2012-01-01

A simulator platform for visualization and demonstration of innovative concepts in fast reactor technology is described. The objective is to make more accessible the workings of fast reactor technology innovations and to do so in a human factors environment that uses state-of-the art visualization technologies. In this work the computer codes in use at Argonne National Laboratory (ANL) for the design of fast reactor systems are being integrated to run on this platform. This includes linking reactor systems codes with mechanical structures codes and using advanced graphics to depict the thermo-hydraulic-structure interactions that give rise to an inherently safe response to upsets. It also includes visualization of mechanical systems operation including advanced concepts that make use of robotics for operations, in-service inspection, and maintenance.

Simulator platform for fast reactor operation and safety technology demonstration

Energy Technology Data Exchange (ETDEWEB)

Vilim, R. B.; Park, Y. S.; Grandy, C.; Belch, H.; Dworzanski, P.; Misterka, J. (Nuclear Engineering Division)

2012-07-30

A simulator platform for visualization and demonstration of innovative concepts in fast reactor technology is described. The objective is to make more accessible the workings of fast reactor technology innovations and to do so in a human factors environment that uses state-of-the art visualization technologies. In this work the computer codes in use at Argonne National Laboratory (ANL) for the design of fast reactor systems are being integrated to run on this platform. This includes linking reactor systems codes with mechanical structures codes and using advanced graphics to depict the thermo-hydraulic-structure interactions that give rise to an inherently safe response to upsets. It also includes visualization of mechanical systems operation including advanced concepts that make use of robotics for operations, in-service inspection, and maintenance.

45 CFR 91.13 - Exceptions to the rules against age discrimination: Normal operation or statutory objective of...

Science.gov (United States)

2010-10-01

... objective of any program or activity. A recipient is permitted to take an action, otherwise prohibited by...: Normal operation or statutory objective of any program or activity. 91.13 Section 91.13 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION NONDISCRIMINATION ON THE BASIS OF AGE IN...

HANARO cooling features: design and experience

International Nuclear Information System (INIS)

Park, Cheol; Chae, Hee-Taek; Han, Gee-Yang; Jun, Byung-Jin; Ahn, Guk-Hoon

1999-01-01

In order to achieve the safe core cooling during normal operation and upset conditions, HANARO adopted an upward forced convection cooling system with dual containment arrangements instead of the forced downward flow system popularly used in the majority of forced convection cooling research reactors. This kind of upward flow system was selected by comparing the relative merits of upward and downward flow systems from various points of view such as safety, performance, maintenance. However, several operational matters which were not regarded as serious at design come out during operation. In this paper are presented the design and operational experiences on the unique cooling features of HANARO. (author)

Seventeen years of LMFBR experience: Experimental Breeder Reactor II (EBR-II)

International Nuclear Information System (INIS)

Perry, W.H.; Lentz, G.L.; Richardson, W.J.; Wolz, G.C.

1982-01-01

Operating experience at EBR-II over the past 17 years has shown that a sodium-cooled pool-type reactor can be safely and efficiently operated and maintained. The reactor has performed predictably and benignly during normal operation and during both unplanned and planned plant upsets. The duplex-tube evaporators and superheaters have never experienced a sodium/water leak, and the rest of the steam-generating system has operated without incident. There has been no noticeable degradation of the heat transfer efficiency of the evaporators and superheaters, except for the one superheater replaced in 1981. There has been no need to perform any chemical cleaning of steam-system components

Self-Testing Computer Memory

Science.gov (United States)

Chau, Savio, N.; Rennels, David A.

1988-01-01

Memory system for computer repeatedly tests itself during brief, regular interruptions of normal processing of data. Detects and corrects transient faults as single-event upsets (changes in bits due to ionizing radiation) within milliseconds after occuring. Self-testing concept surpasses conventional by actively flushing latent defects out of memory and attempting to correct before accumulating beyond capacity for self-correction or detection. Cost of improvement modest increase in complexity of circuitry and operating time.

Solar particle induced upsets in the TDRS-1 attitude control system RAM during the October 1989 solar particle events

International Nuclear Information System (INIS)

Croley, D.R.; Garrett, H.B.; Murphy, G.B.; Garrard, T.L.

1995-01-01

The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo, designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEU's calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEU's by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU's. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU's was 72, yielding a total of 248 predicted SEU's, very close to the 243 observed SEU's

Switchable Q-switched and modelocked operation in ytterbium doped fiber laser under all-normal-dispersion configuration

Energy Technology Data Exchange (ETDEWEB)

Mukhopadhyay, Pranb K., E-mail: pkm@rrcat.gov.in; Gupta, Pradeep K.; Singh, Chandra Pal; Singh, Amarjeet; Sharma, Sunil K.; Bindra, Kushvinder S.; Oak, Shrikant M. [Solid State Laser Division, Raja Ramanna Center for Advanced Technology, Indore, M.P. 452013 (India)

2015-03-15

We have constructed an Yb-doped fiber laser in all-normal-dispersion configuration which can be independently operated in Q-switched or modelocked configuration with the help of a simple fiber optic ring resonator (FORR). In the presence of FORR, the laser operates in Q-switched mode producing stable pulses in the range of 1 μs-200 ns with repetition rate in the range of 45 kHz-82 kHz. On the other hand, the laser can be easily switched to mode-locked operation by disjoining the FORR loop producing train of ultrashort pulses of ∼5 ps duration (compressible to ∼150 fs) at ∼38 MHz repetition rate. The transmission characteristics of FORR in combination with the nonlinear polarization rotation for passive Q-switching operation is numerically investigated and experimentally verified. The laser can serve as a versatile seed source for power amplifier which can be easily configured for application in the fields that require different pulsed fiber lasers.

Impact of temperature on single event upset measurement by heavy ions in SRAM devices

International Nuclear Information System (INIS)

Liu Tianqi; Geng Chao; Zhang Zhangang; Gu Song; Tong Teng; Xi Kai; Hou Mingdong; Liu Jie; Zhao Fazhan; Liu Gang; Han Zhengsheng

2014-01-01

The temperature dependence of single event upset (SEU) measurement both in commercial bulk and silicon on insulator (SOI) static random access memories (SRAMs) has been investigated by experiment in the Heavy Ion Research Facility in Lanzhou (HIRFL). For commercial bulk SRAM, the SEU cross section measured by 12 C ions is very sensitive to the temperature. The temperature test of SEU in SOI SRAM was conducted by 209 Bi and 12 C ions, respectively, and the SEU cross sections display a remarkable growth with the elevated temperature for 12 C ions but keep constant for 209 Bi ions. The impact of temperature on SEU measurement was analyzed by Monte Carlo simulation. It is revealed that the SEU cross section is significantly affected by the temperature around the threshold linear energy transfer of SEU occurrence. As the SEU occurrence approaches saturation, the SEU cross section gradually exhibits less temperature dependency. Based on this result, the experimental data measured in HIRFL was analyzed, and then a reasonable method of predicting the on-orbit SEU rate was proposed. (semiconductor devices)

An estimation of population doses from a nuclear power plant during normal operation

International Nuclear Information System (INIS)

Nowicki, K.

1975-07-01

A model is presented for estimation of the potential submersion and inhalation radiation doses to people located within a distance of 1000 km from a nuclear power plant during normal operation. The model was used to calculate doses for people living 200-1000 km from hypothetical nuclear power facility sited near the geographical centre of Denmark. Two kinds of sources are considered for this situation: - unit release of 15 isotopes of noble gases and iodines, - effluent releases from two types of 1000 MWe Light Water Power Reactors: PWR and BWR. Parameter variations were made and analyzed in order to obtain a better understanding of the mechanisms of the model. (author)

Environmental impact assessment of Ar-41 released by the normal operation of TRIGA-Mark 2 research reactor

International Nuclear Information System (INIS)

Qassoud, D.; Soufi, I.; Ziagos, J.; Demir, Z

2007-01-01

Full text: In accordance with the international regulation of nuclear safety and radiological protection of the environment applicable to the basic nuclear installations, category in which the Triga-Mark 2 research reactor is considered, an assesment of the impact in to the environment of the Ar-41 radioelement is accomplished. This radioelement is released by the normal operation of this reactor. The assessment is based on the characteristics of a Moroccan site (where the reactor is installed). It is carried out using CEA Gaussian models and mathematical models developed in LLNL. Considering the assumptions of impact assessments of the radioactivity in the atmosphere, the most important exposure is relatively corresponding to 1 Km from the reactor. This exposure is approximately 0,07% of the lawful limit. Beyond this locality, the exposure becomes lower than 0,02% of this limit. Beyond 5 Km, it becomes lower than ten nono-Sivert. In the basis of the site radiological baseline, the environmental impact of Ar-41 released in normal operation of the reactor is negligible in the studied case. [fr

Probabilistic fracture mechanics of nuclear structural components. Consideration of transition from embedded crack to surface crack

International Nuclear Information System (INIS)

Yagawa, Genki; Yoshimura, Shinobu; Kanto, Yasuhiro

1998-01-01

This paper describes a probabilistic fracture mechanics (PFM) analysis of aged nuclear reactor pressure vessel (RPV) material. New interpolation formulas are first derived for both embedded elliptical surface cracks and semi-elliptical surface cracks. To investigate effects of transition from embedded crack to surface crack in PFM analyses, one of PFM round-robin problems set by JSME-RC111 committee, i.e. 'aged RPV under normal and upset operating conditions' is solved, employing the interpolation formulas. (author)

Technical Task and Quality Assurance Plan in Support of BNFL Part B: Studies of Ion Exchange Resin Integrity under Flowsheet Extremes: Part II

International Nuclear Information System (INIS)

Nash, C.A.

2000-01-01

This task will address four items related to ion exchange stability: (1) process upset evaluation of resin in contact with 1 molar sodium permanganate at 25 and 40 degrees C, (2) accelerated aging with nitric acid solution used during normal regeneration operations, (3) prolonged contacting of SuperLig 644 resin with 5 molar nitric acid at room temperature, and (4) prolonged contacting of SuperLig 644 resin with deionized water at 60 plus/minus 5 degrees C

Design report on the guide box-reactivity and safety control plates for MPR reactor under normal operation conditions

International Nuclear Information System (INIS)

Markiewicz, M.

1999-01-01

The reactivity control system for the MPR reactor (Multi Purpose Reactor) is a critical component regarding safety, it must ensure a fast shut down, maintaining the reactor in subcritical condition under normal or accidental operation condition. For this purpose, this core component must be designed to maintain its operating capacity during all the residence time and under any foreseen operation condition. The mechanical design of control plates and guide boxes must comply with structural integrity, maintaining its geometric and dimensional stability within the pre-established limits to prevent interferences with other core components. For this, the heat generation effect, mechanical loads and environment and irradiation effects were evaluated during the mechanical design. The reactivity control system is composed of guide boxes, manufactured from Aluminium alloy, located between the fuel elements, and control absorber plates of Ag-In-Cd alloy hermetically enclosed by a cladding of stainless steel sliding inside de guide boxes. The upward-downward movement is transmitted by a rod from the motion device located at the reactor lower part. The design requirements, criteria and limits were established to fulfill with the normal and abnormal operation conditions. The design verifications were performed by analytical method, estimating the guide box and control plates residence time. The result of the analysis performed, shows that the design of the reactivity control system and the material selected, are appropriate to fulfill the functional requirements, with no failures attributed to the mechanical design. (author)

Fracture assessment of Savannah River Reactor carbon steel piping

International Nuclear Information System (INIS)

Mertz, G.E.; Stoner, K.J.; Caskey, G.R.; Begley, J.A.

1991-01-01

The Savannah River Site (SRS) production reactors have been in operation since the mid-1950's. One postulated failure mechanism for the reactor piping is brittle fracture of the original A285 and A53 carbon steel piping. Material testing of archival piping determined (1) the static and dynamic tensile properties; (2) Charpy impact toughness; and (3) the static and dynamic compact tension fracture toughness properties. The nil-ductility transition temperature (NDTT), determined by Charpy impact test, is above the minimum operating temperature for some of the piping materials. A fracture assessment was performed to demonstrate that potential flaws are stable under upset loading conditions and minimum operating temperatures. A review of potential degradation mechanisms and plant operating history identified weld defects as the most likely crack initiation site for brittle fracture. Piping weld defects, as characterized by radiographic and metallographic examination, and low fracture toughness material properties were postulated at high stress locations in the piping. Normal operating loads, upset loads, and residual stresses were assumed to act on the postulated flaws. Calculated allowable flaw lengths exceed the size of observed weld defects, indicating adequate margins of safety against brittle fracture. Thus, a detailed fracture assessment was able to demonstrate that the piping systems will not fail by brittle fracture, even though the NDTT for some of the piping is above the minimum system operating temperature

Assessment of Radionuclides Release from Inshas LILW Disposal Facility Under Normal and Unusual Operational Conditions

International Nuclear Information System (INIS)

Zaki, A.A.

2008-01-01

Disposing of low and intermediate radioactive waste (LILW) is a big concern for Egypt due to the accumulated waste as a result of past fifty years of peaceful nuclear applications. Assessment of radionuclides release from Inshas LILW disposal facility under normal and unusual operational conditions is very important in order to apply for operation license of the facility. Aqueous release of radionuclides from this disposal facility is controlled by water flow, access of the water to the wasteform, release of the radionuclides from the wasteform, and transport to the disposal facility boundary. In this work, the release of 137 Cs , 6C o, and 90 Sr radionuclides from the Inshas disposal facility was studied under the change of operational conditions. The release of these radio contaminants from the source term to the unsaturated and saturated zones , to groundwater were studied. It was found that the concentration of radionuclides in a groundwater well located 150 m away from the Inshas disposal facility is less than the maximum permissible concentration in groundwater in both cases

Evaluating new methods for direct measurement of the moderator temperature coefficient in nuclear power plants during normal operation

International Nuclear Information System (INIS)

Makai, M.; Kalya, Z.; Nemes, I.; Pos, I.; Por, G.

2007-01-01

Moderator temperature coefficient of reactivity is not monitored during fuel cycles in WWER reactors, because it is not very easy or impossible to measure it without disturbing the normal operation. Two new methods were tested in our WWER type nuclear power plant to try methodologies, which enable to measure that important to safety parameter during the fuel cycle. One is based on small perturbances, and only small changes are requested in operation, the other is based on noise methods, which means it is without interference with reactor operation. Both method is new that aspects that they uses the plant computer data(VERONA) based signals calculated by C P ORCA diffusion code (Authors)

Development of a Nuclear Reaction Database on Silicon for Simulation of Neutron-Induced Single-Event Upsets in Microelectronics and its Application

International Nuclear Information System (INIS)

Watanabe, Yukinobu; Kodama, Akihiro; Tukamoto, Yasuyuki; Nakashima, Hideki

2005-01-01

We have developed a cross-section database for neutron-induced reactions on 28Si in the energy range between 2 MeV and 3 GeV in order to analyze single-event upsets (SEUs) phenomena induced by cosmic-ray neutrons in microelectronic devices. A simplified spherical device model is proposed for simulation of the initial processes of SEUs. The model is applied to SEU cross-section calculations for semiconductor memory devices. The calculated results are compared with measured SEU cross sections and the other simulation result. The dependence of SEU cross sections on incident neutron energy and secondary ions having the most important effects on SEUs are discussed

Chrysler Upset Protrusion Joining Techniques for Joining Dissimilar Metals

Energy Technology Data Exchange (ETDEWEB)

Logan, Stephen [FCA US LLC, Auburn Hills, MI (United States)

2017-09-28

The project goal was to develop and demonstrate a robust, cost effective, and versatile joining technique, known as Upset Protrusion Joining (UPJ), for joining challenging dissimilar metal com-binations, especially those where one of the metals is a die cast magnesium (Mg) component. Since two of the key obstacles preventing more widespread use of light metals (especially in high volume automotive applications) are 1) a lack of robust joining techniques and 2) susceptibility to galvanic corrosion, and since the majority of the joint combinations evaluated in this project include die cast Mg (the lightest structural metal) as one of the two materials being joined, and since die casting is the most common and cost effective process for producing Mg components, then successful project completion provides a key enabler to high volume application of lightweight materials, thus potentially leading to reduced costs, and encouraging implementation of lightweight multi-material vehicles for significant reductions in energy consumption and reduced greenhouse gas emissions. Eco-nomic benefits to end-use consumers are achieved primarily via the reduction in fuel consumption. Unlike currently available commercial processes, the UPJ process relies on a very robust mechanical joint rather than intermetallic bonding, so the more cathodic material can be coated prior to joining, thus creating a robust isolation against galvanic attack on the more anodic material. Additionally, since the UPJ protrusion is going through a hole that can be pre-drilled or pre-punched prior to coating, the UPJ process is less likely to damage the coating when the joint is being made. Further-more, since there is no additional cathodic material (such as a steel fastener) used to create the joint, there is no joining induced galvanic activity beyond that of the two parent materials. In accordance with its originally proposed plan, this project has successfully developed process variants of UPJ to enable

On commuting operator exponentials, II

Indian Academy of Sciences (India)

where N is an unbounded normal operator and M is a bounded normal operator in the. Hilbert space. Keywords. Self-adjoint and normal operator; commuting normal operator exponent- ials; Borel functional calculus. 1. Introduction. Let E be a complex Hilbert space and let B(E) be the algebra of bounded linear operators.

Operative findings of conductive hearing loss with intact tympanic membrane and normal temporal bone computed tomography.

Science.gov (United States)

Kim, Se-Hyung; Cho, Yang-Sun; Kim, Hye Jeong; Kim, Hyung-Jin

2014-06-01

Despite recent technological advances in diagnostic methods including imaging technology, it is often difficult to establish a preoperative diagnosis of conductive hearing loss (CHL) in patients with an intact tympanic membrane (TM). Especially, in patients with a normal temporal bone computed tomography (TBCT), preoperative diagnosis is more difficult. We investigated middle ear disorders encountered in patients with CHL involving an intact TM and normal TBCT. We also analyzed the surgical results with special reference to the pathology. We reviewed the medical records of 365 patients with intact TM, who underwent exploratory tympanotomy for CHL. Fifty nine patients (67 ears, eight bilateral surgeries) had a normal preoperative TBCT findings reported by neuro-radiologists. Demographic data, otologic history, TM findings, preoperative imaging findings, intraoperative findings, and pre- and postoperative audiologic data were obtained and analyzed. Exploration was performed most frequently in the second and fifth decades. The most common postoperative diagnosis was stapedial fixation with non-progressive hearing loss. The most commonly performed hearing-restoring procedure was stapedotomy with piston wire prosthesis insertion. Various types of hearing-restoring procedures during exploration resulted in effective hearing improvement, especially with better outcome in the ossicular chain fixation group. In patients with CHL who have intact TM and normal TBCT, we should consider an exploratory tympanotomy for exact diagnosis and hearing improvement. Information of the common operative findings from this study may help in preoperative counseling.

Effects of the solar-terrestrial environment on satellite operations

International Nuclear Information System (INIS)

Baker, D.N.

1984-01-01

Hot plasma and energetic particle populations in space are known to produce spacecraft operational anomalies. In the inner part of the earth's magnetosphere, these effects are primarily due to durably trapped radiation belt particles, and the integrated doses can be calculated quite accurately for any given orbit. In the outer magnetosphere many spacecraft operational problems appear to be due to intense, transient phenomena. It is shown that three types of naturally-occurring, and highly variable, hostile particle radiation environments are encountered at, or near, the geostationary orbit: (1) high-energy protons due to solar flares; (2) very high energy electrons (2-10 MeV) of unknown origin; and (3) energetic ions and electrons produced by magnetospheric substorms. Present particle sensor systems provide energetic particle detection and assessment capabilities during these kinds of high-energy radiation events. Numerous operational anomalies and subsystem problems have occurred during each type of event period and the association of such upsets is demonstrated in this paper. Methods of prediction of magnetospheric disturbances are discussed, and overall recommendations are made for dealing with this continuing problem

Monte Carlo calculation of the cross-section of single event upset induced by 14MeV neutrons

International Nuclear Information System (INIS)

Li, H.; Deng, J.Y.; Chang, D.M.

2005-01-01

High-density static random access memory may experience single event upsets (SEU) in neutron environments. We present a new method to calculate the SEU cross-section. Our method is based on explicit generation and transport of the secondary reaction products and detailed accounting for energy loss by ionization. Instead of simulating the behavior of the circuit, we use the Monte Carlo method to simulate the process of energy deposition in sensitive volumes. Thus, we do not need to know details about the circuit. We only need a reasonable guess for the size of the sensitive volumes. In the Monte Carlo simulation, the cross-section of SEU induced by 14MeV neutrons is calculated. We can see that the Monte Carlo simulation not only can provide a new method to calculate SEU cross-section, but also can give a detailed description about random process of the SEU

Probabilistic fracture mechanics of nuclear structural components: consideration of transition from embedded crack to surface crack

International Nuclear Information System (INIS)

Yagawa, G.; Yoshimura, S.

1999-01-01

This paper describes a probabilistic fracture mechanics (PFM) analysis of aged nuclear reactor pressure vessel (RPV) material. New interpolation formulas of three-dimensional stress intensity factors are presented for both embedded elliptical surface cracks and semi-elliptical surface cracks. To investigate effects of transition from embedded crack to surface crack in PFM analyses, one of the PFM round-robin problems set by JSME-RC111 committee (i.e. aged RPV under normal and upset operating conditions) is solved, employing the interpolation formulas. (orig.)

Reliability analysis of meteorological data registered during nuclear power plant normal operation

International Nuclear Information System (INIS)

Amado, V.; Ulke, A.; Marino, B.; Thomas, L.

2011-01-01

The atmosphere is the environment in which gaseous radioactive discharges from nuclear power plants are transported. It is therefore essential to have reliable meteorological information to characterize the dispersion and feed evaluation models and radiological environmental impact during normal operation of the plant as well as accidental releases. In this way it is possible to determine the effects on the environment and in humans. The basic data needed to represent adequately the local weather include air temperature, wind speed and direction, rainfall, humidity and pressure. On the other hand, specific data consistent with the used model is required to determine the turbulence, for instance, radiation, cloud cover and vertical temperature gradient. It is important that the recorded data are representative of the local meteorology. This requires, first, properly placed instruments, that should be kept in operation and undergoing maintenance on a regular basis. Second, but equally substantial, a thorough analysis of its reliability must be performed prior to storage and/or data processing. In this paper we present the main criteria to consider choosing the location of a meteorological tower in the area of a nuclear power plant and propose a methodology for assessing the reliability of recorded data. The methodology was developed from the analysis of meteorological data registered in nuclear power plants in Argentina. (authors) [es

Densification of sintered molybdenum during hot upsetting: experiments and modelling

International Nuclear Information System (INIS)

Parteder, E.; Kopp, R.

1999-01-01

The densification behaviour of sintered molybdenum is investigated experimentally and by modelling using a pressure dependent plasticity model. Therefore the yield condition of Gurson, extended by Tvergaard is used. The uniaxial compression test is applied to determine the evolution of the density as well as the stress-strain curves for the porous metal. Powder metallurgical molybdenum exhibits closed porosity after consolidation due to sintering with nearly spherical shaped pores. The experimental results show that the densification, especially during the first stage of deformation, is different from that of powder compacts or partially consolidated powder materials with open porosity. During hot upsetting, the pores change their size and shape. This behaviour strongly affects the densification rate. For an accurate prediction of the evolution of the density using Gurson's model, the parameters q 1 and q 2 introduced by Tvergaard, will be defined as internal variables. The use of internal variables is justified by the fact that the pores change their shape during deformation, although the link between the internal variables and the pore shape is not explicitly established in this paper. If the loading is proportional (which means that the ratio of the stress-components does not change with plastic strain), the pore shape can be associated with the applied plastic strain. With this association the parameters q i can be defined as a function from the invariant quantity equivalent plastic strain, which can be used as the internal variable in the finite element simulation. The influence of the porosity on the flow stress at different levels of plastic strain will also be investigated and is used as a second information to fit both parameters q 1 and q 2 . (orig.)

Jules Horowitz Reactor: Organisation for the Preparation of the Commissioning Phase and Normal Operation

Energy Technology Data Exchange (ETDEWEB)

Estrade, J.; Fabre, J. L.; Marcille, O. [French Alternative Energies end Atomic Energy Commission, Provence (France)

2013-07-01

The Jules Horowitz Reactor (JHR) is a new modern Material Testing Reactor (MTR) currently under construction at CEA Cadarache research centre in the south of France. It will be a major research facility in support to the development and the qualification of materials and fuels under irradiation with sizes and environment conditions relevant for nuclear power plants in order to optimise and demonstrate safe operations of existing power reactors as well as to support future reactors design. It will represent also an important research infrastructure for scientific studies dealing with material and fuel behaviour under irradiation. The JHR will contribute also to secure the production of radioisotope for medical application. This is a key public health stake. The construction of JHR which started in 2007 is going-on with target of commissioning by the end of 2017. The design of the reactor provides modern experimental capacity in support to R and D programs for the nuclear energy for the next 60 years. In parallel to the facility construction, the preparation of the future staff and of the organisation to operate the reactor safely, reliably and efficiently is an important issue. In this framework, many actions are in progress to elaborate: Ο the staffing and the organisational structure for the commissioning test phases and also for normal operation, Ο the documentation in support to the reactor operation (safety analysis report, general operating rules, procedures, instructions, ···), Ο the maintenance, in service and periodic test programs, Ο staff training programs by using dedicated facilities (simulator, ···) Ο commissioning test programs for ensuring that the layout of systems and subcomponents is completed in accordance with the design requirements, the specification performances and the safety criteria. These commissioning tests will also be helpful for transferring the knowledge on the installed systems to the operating group. This paper gives the

Solar Particle Induced Upsets in the TDRS-1 Attitude Control System RAM During the October 1989 Solar Particle Events

Science.gov (United States)

Croley, D. R.; Garrett, H. B.; Murphy, G. B.; Garrard,T. L.

1995-01-01

The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo, designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEU's calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEU's by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU'S. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU's was 72, yielding a total of 248 predicted SEU'S, very dose to the 243 observed SEU'S. These calculations uniquely demonstrate the roles that solar heavy ions and protons played in the production of SEU

Fatigue crack growth analysis of a 450 PWR - lateral

International Nuclear Information System (INIS)

Taupin, P.; Flamand, F.

1988-01-01

Fatigue Crack Growth analysis of a 5 mm deep surface crack in the crotch region of a 45 0 Lateral (12 inch diameter) was performed on a 3-Loop 900 MWe PWR Plant under Normal and upset loading conditions. Stress Intensity factors were computed using the weight-function technique. The latter were obtained for a polynomial stress distribution at the corner of the lateral under contract with the Pressure Vessel Research Committee of the WRC. The study shows that after 40 years of normal operation the size of the end of life crack is limited to about 25 mm for the chosen lateral with a thickness of 300 mm

Transforming Normal Programs by Replacement

NARCIS (Netherlands)

Bossi, Annalisa; Pettorossi, A.; Cocco, Nicoletta; Etalle, Sandro

1992-01-01

The replacement transformation operation, already defined in [28], is studied wrt normal programs. We give applicability conditions able to ensure the correctness of the operation wrt Fitting's and Kunen's semantics. We show how replacement can mimic other transformation operations such as thinning,

On an inequality for non-normal operators

International Nuclear Information System (INIS)

Duggal, B.P.

1992-07-01

Starting from the inequality proved by Takayuki Furuta for a dominant operator A on a complex Hilbert space H, which extends to all operators such that the pure part of A has empty point spectrum, it is shown that if A is a contraction (on a separable complex Hilbert space) with simple eigenvalues and C 0 completely non-unitary part, and if (1-A*A) 1/2 is of Hilbert-Schmidt class, then the said inequality holds for A. 8 refs

Evaluation of the StressWave Cold Working (SWCW) Process on High-Strength Aluminum Alloys for Aerospace

Science.gov (United States)

2009-02-01

Alloy Spot- welds by Cold Working,” 13 International Pacific Conference on Automotive Engineering (IPC-13), Gyeongju, Korea, August 2005. 7. Kim...so that it remains normal to the indenting direction. The restraint provided around the area to be cold worked minimizes surface upset (albeit...direction. The restraint provided around the area to be cold worked minimizes surface upset (albeit small without a PF). The stabilizing aspect

Operating experience in correcting severe secondary chemistry upsets by controlling makeup water organics (TOC)

International Nuclear Information System (INIS)

Flint, W.G.; Mc Intosh, R.J.

1986-01-01

In this paper following observations are presented: conductivity and chloride excursions in steam condensate were directly linked to makeup water quality. Data strongly suggests that the breakdown of makeup water organics was responsible for substandard condensate water quality; although the short-term effects of gross organic contamination have been documented, the longer term consequences of continuous exposure by moderate organic levels needs to be addressed; a greater understanding of the organic removal efficiency of the various water purification technologies is essential to controlling TOC contamination; and a much better understanding of makeup plant chemistry and the interrelationship of makeup water contamination and plant chemistry has proven essential to optimizing plant performance and guaranteeing the best possible steam chemistry. The role of the chemistry group as an active participant in operations has been proven at Kewaunee Nuclear Plant

Compact reactor/ORC power source

International Nuclear Information System (INIS)

Meier, K.L.; Kirchner, W.L.; Willcutt, G.J.

1986-01-01

A compact power source that combines an organic Rankine Cycle (ORC) electric generator with a nuclear reactor heat source is being designed and fabricated. Incorporating existing ORC technology with proven reactor technology, the compact reactor/ORC power source offers high reliability while minimizing the need for component development. Thermal power at 125 kWt is removed from the coated particle fueled, graphite moderated reactor by heat pipes operating at 500 0 C. Outside the reactor vessel and connected to the heat pipes are vaporizers in which the toluene ORC working fluid is heated to 370 0 C. In the turbine-alternator-pump (TAP) combined-rotating unit, the thermal energy of the toluene is converted to 25 kWe of electric power. Lumped parameter systems analyses combined with a finite element thermal analysis have aided in the power source design. The analyses have provided assurance of reliable multiyear normal operation as well as full power operation with upset conditions, such as failed heat pipes and inoperative ORC vaporizers. Because of inherent high reliability, long life, and insensitivity to upset conditions, this power source is especially suited for use in remote, inaccessible locations where fuel delivery and maintenance costs are high. 10 refs

A compact reactor/ORC power source

International Nuclear Information System (INIS)

Meier, K.L.; Kirchner, W.L.; Willcutt, G.J.

1986-01-01

A compact power source that combines an organic Rankine cycle (ORC) electric generator with a nuclear reactor heat source is being designed and fabricated. Incorporating existing ORC technology with proven reactor technology, the compact reactor/ORC power source offers high reliability while minimizing the need for componenet development. Thermal power at 125 kWt is removed from the coated particle fueled, graphite moderated reactor by heat pipes operating at 500 0 C. Outside the reactor vessel and connected to the heat pipes are vaporizers in which the toluene ORC working fluid is heated to 370 0 C. In the turbine-alternator-pump (TAP) combined-rotating unit, the thermal energy of the toluene is converted to 25 kWe of electric power. Lumped parameter systems analyses combined with a finite element thermal analyses combined with a finite element thermal analysis have aided in the power source design. The analysis have provided assurance of reliable multiyear normal operation as well as full power operation with upset conditions, such as failed heat pipes and inoperative ORC vaporizers. Because of inherent high reliability, long life, and insensitivity to upset conditions, this power source is especially suited for use in remote, inaccessible locations where fuel delivery and maintenance costs are high

The FOCON model to assess doses due to the atmospheric radioactive discharges of nuclear facilities during normal operation

International Nuclear Information System (INIS)

Rommens, C.; Morin, A.; Merle-Szeremeta, A.

1999-01-01

The FOCON model to assess doses due to the atmospheric radioactive discharges of nuclear facilities during normal operation. To assess the dosimetric impact to the public due to atmospheric radioactive discharges of nuclear facilities during normal operation, the Institute for Protection and Nuclear Safety has developed the FOCON96 code. FOCON96 calculates the dispersion of gases and aerosols into the environment (atmosphere contamination and ground deposition), their transfer in the biosphere (soils, plants and animals) and their impact to a member of the public (individual effective and equivalent doses, external exposure to the plume and to the deposits, internal exposure by inhalation and ingestion). FOCON96 uses ergonomic windows and proposes many capabilities (modular architecture, default values, choice of libraries, access to all the parameters of the models, listing or results, management of result files, calculations made directly, etc.). In the European context, and intercomparison with the PC-CREAM code, developed by the National Radiological Protection Board, has shown the coherence of the results of the two codes. A comparison of the windows and capabilities has shown that FOCON96 was easier to use. FOCON96 is not adapted to calculate the doses received during one particular year that are due to the discharges of a facility in operation for a long period of time. An evolution of the software will be considered if this kind of assessment is generalized. (authors)

Assessment of margins with respect to pressurized thermal shock for the 3 loop plants of the French program

International Nuclear Information System (INIS)

Buchalet, C.; Haussaire, P.; Houssin, B.; Vagner, J.

1983-08-01

Presentation of the FRAMATOME and EDF program on pressurized thermal shock which objectives are to demonstrate that present and older French reactor vessels have adequate safety margins and to provide recommendations of feasible plant specific modifications, both technically and economically. Phase I consists in a thorough analysis of pressure and temperature transients that the R.P.V. beltine could undergo during plant operations; phase II is the fracture mechanics analysis; phase III estimates the safety margins available during normal, upset, emergency and faulted conditions

New operator assistance features in the CMS Run Control System

CERN Document Server

Andre, Jean-Marc Olivier; Branson, James; Brummer, Philipp Maximilian; Chaze, Olivier; Cittolin, Sergio; Contescu, Cristian; Craigs, Benjamin Gordon; Darlea, Georgiana Lavinia; Deldicque, Christian; Demiragli, Zeynep; Dobson, Marc; Doualot, Nicolas; Erhan, Samim; Fulcher, Jonathan F; Gigi, Dominique; Michail Gładki; Glege, Frank; Gomez Ceballos, Guillelmo; Hegeman, Jeroen Guido; Holzner, Andre Georg; Janulis, Mindaugas; Jimenez Estupinan, Raul; Masetti, Lorenzo; Meijers, Franciscus; Meschi, Emilio; Mommsen, Remigius; Morovic, Srecko; O'Dell, Vivian; Orsini, Luciano; Paus, Christoph Maria Ernst; Petrova, Petia; Pieri, Marco; Racz, Attila; Reis, Thomas; Sakulin, Hannes; Schwick, Christoph; Simelevicius, Dainius; Zejdl, Petr; Vougioukas, M.

2017-01-01

The Run Control System of the Compact Muon Solenoid (CMS) experiment at CERN is a distributed Java web application running on Apache Tomcat servers. During Run-1 of the LHC, many operational procedures have been automated. When detector high voltages are ramped up or down or upon certain beam mode changes of the LHC, the DAQ system is automatically partially reconfigured with new parameters. Certain types of errors such as errors caused by single-event upsets may trigger an automatic recovery procedure. Furthermore, the top-level control node continuously performs cross-checks to detect sub-system actions becoming necessary because of changes in configuration keys, changes in the set of included front-end drivers or because of potential clock instabilities. The operator is guided to perform the necessary actions through graphical indicators displayed next to the relevant command buttons in the user interface. Through these indicators, consistent configuration of CMS is ensured. However, manually following t...

Development of dose assessment code for release of tritium during normal operation of nuclear power plants

International Nuclear Information System (INIS)

Duran, J.; Malatova, I.

2009-01-01

A computer code PTM H TO has been developed to assess tritium doses to the general public. The code enables to simulate the behavior of tritium in the environment released into the atmosphere under normal operation of nuclear power plants. Code can calculate the doses for the three chemical and physical forms: tritium gas (HT), tritiated water vapor and water drops (HTO). The models in this code consist of the tritium transfer model including oxidation of HT to HTO and reemission of HTO from soil to the atmosphere, and the dose calculation model

A Current-Mode Common-Mode Feedback Circuit (CMFB) with Rail-to-Rail Operation

Science.gov (United States)

Suadet, Apirak; Kasemsuwan, Varakorn

2011-03-01

This paper presents a current-mode common-mode feedback (CMFB) circuit with rail-to-rail operation. The CMFB is a stand-alone circuit, which can be connected to any low voltage transconductor without changing or upsetting the existing circuit. The proposed CMFB employs current mirrors, operating as common-mode detector and current amplifier to enhance the loop gain of the CMFB. The circuit employs positive feedback to enhance the output impedance and gain. The circuit has been designed using a 0.18 μm CMOS technology under 1V supply and analyzed using HSPICE with BSIM3V3 device models. A pseudo-differential amplifier using two common sources and the proposed CMFB shows rail to rail output swing (± 0.7 V) with low common-mode gain (-36 dB) and power dissipation of 390 μW.

The supply voltage scaled dependency of the recovery of single event upset in advanced complementary metal—oxide—semiconductor static random-access memory cells

International Nuclear Information System (INIS)

Li Da-Wei; Qin Jun-Rui; Chen Shu-Ming

2013-01-01

Using computer-aided design three-dimensional simulation technology, the supply voltage scaled dependency of the recovery of single event upset and charge collection in static random-access memory cells are investigated. It reveals that the recovery linear energy transfer threshold decreases with the supply voltage reducing, which is quite attractive for dynamic voltage scaling and subthreshold circuit radiation-hardened design. Additionally, the effect of supply voltage on charge collection is also investigated. It is concluded that the supply voltage mainly affects the bipolar gain of the parasitical bipolar junction transistor (BJT) and the existence of the source plays an important role in supply voltage variation. (geophysics, astronomy, and astrophysics)

Testable, fault-tolerant power interface circuit for normally de-energized loads

International Nuclear Information System (INIS)

Hager, R.E.

1987-01-01

A power interface circuit is described for supplying power from a power line to a normally de-energized process control apparatus in a pressurized light water nuclear power system in dependence upon three input signals, comprising: voter means for supplying power to the normally de-energized load when at least two of the three input signals indicate that the normally de-energized load should be activated; a normally closed switch, operatively connected to the power line and the voter means, for supplying power to the voter means during ordinary operation; a first resistor operatively connected to the power line; a current detector operatively connected to the first resistor and the voter means; a second resistor operatively connected to the current detector and ground; and current sensor means, operatively connected between the voter means and the normally de-energized load, for detecting the power supplied to the normally de-energized load by the voter means

Worst-case prediction of normal operating containment temperatures for environmentally qualified equipment

International Nuclear Information System (INIS)

Krasnopoler, M.J.; Sundergill, J.E.

1991-01-01

Due to issues raised in NRC Information Notice No. 87-65, a southern US nuclear plant was concerned about thermal aging of environmentally qualified (EQ) equipment located in areas of elevated containment temperatures. A method to predict the worst-case monthly temperatures at various zones in the containment and calculate the qualified life using this monthly temperature was developed. Temperatures were predicted for twenty locations inside the containment. Concern about the qualified life of EQ equipment resulted from normal operating temperatures above 120F in several areas of the containment, especially during the summer. At a few locations, the temperature exceeded 140F. Also, NRC Information Notice No. 89-30 reported high containment temperatures at three other nuclear power plants. The predicted temperatures were based on a one-year containment temperature monitoring program. The monitors included permanent temperature monitors required by the Technical Specifications and temporary monitors installed specifically for this program. The temporary monitors were installed near EQ equipment in the expected worst-case areas based on design and operating experience. A semi-empirical model that combined physical and statistical models was developed. The physical model was an overall energy balance for the containment. The statistical model consists of several linear regressions that conservatively relate the monitor temperatures to the bulk containment temperature. The resulting semi-empirical model predicts the worst-case monthly service temperatures at the location of each of the containment temperature monitors. The monthly temperatures are the maximum expected because they are based on the historically worst-case atmospheric data

Normalization as a canonical neural computation

Science.gov (United States)

Carandini, Matteo; Heeger, David J.

2012-01-01

There is increasing evidence that the brain relies on a set of canonical neural computations, repeating them across brain regions and modalities to apply similar operations to different problems. A promising candidate for such a computation is normalization, in which the responses of neurons are divided by a common factor that typically includes the summed activity of a pool of neurons. Normalization was developed to explain responses in the primary visual cortex and is now thought to operate throughout the visual system, and in many other sensory modalities and brain regions. Normalization may underlie operations such as the representation of odours, the modulatory effects of visual attention, the encoding of value and the integration of multisensory information. Its presence in such a diversity of neural systems in multiple species, from invertebrates to mammals, suggests that it serves as a canonical neural computation. PMID:22108672

Space Weather Impacts on Spacecraft Operations: Identifying and Establishing High-Priority Operational Services

Science.gov (United States)

Lawrence, G.; Reid, S.; Tranquille, C.; Evans, H.

2013-12-01

Space Weather is a multi-disciplinary and cross-domain system defined as, 'The physical and phenomenological state of natural space environments. The associated discipline aims, through observation, monitoring, analysis and modelling, at understanding and predicting the state of the Sun, the interplanetary and planetary environments, and the solar and non-solar driven perturbations that affect them, and also at forecasting and nowcasting the potential impacts on biological and technological systems'. National and Agency-level efforts to provide services addressing the myriad problems, such as ESA's SSA programme are therefore typically complex and ambitious undertakings to introduce a comprehensive suite of services aimed at a large number and broad range of end users. We focus on some of the particular threats and risks that Space Weather events pose to the Spacecraft Operations community, and the resulting implications in terms of User Requirements. We describe some of the highest-priority service elements identified as being needed by the Operations community, and outline some service components that are presently available, or under development. The particular threats and risks often vary according to orbit, so the particular User Needs for Operators at LEO, MEO and GEO are elaborated. The inter-relationship between these needed service elements and existing service components within the broader Space Weather domain is explored. Some high-priority service elements and potential correlation with Space Weather drivers include: solar array degradation and energetic proton storms; single event upsets at GEO and solar proton events and galactic cosmic rays; surface charging and deep dielectric charging at MEO and radiation belt dynamics; SEUs at LEO and the South Atlantic Anomaly and its variability. We examine the current capability to provide operational services addressing such threats and identify some advances that the Operations community can expect to benefit

3j Symbols: To Normalize or Not to Normalize?

Science.gov (United States)

van Veenendaal, Michel

2011-01-01

The systematic use of alternative normalization constants for 3j symbols can lead to a more natural expression of quantities, such as vector products and spherical tensor operators. The redefined coupling constants directly equate tensor products to the inner and outer products without any additional square roots. The approach is extended to…

Radiation-hardened MRAM-based LUT for non-volatile FPGA soft error mitigation with multi-node upset tolerance

Science.gov (United States)

Zand, Ramtin; DeMara, Ronald F.

2017-12-01

In this paper, we have developed a radiation-hardened non-volatile lookup table (LUT) circuit utilizing spin Hall effect (SHE)-magnetic random access memory (MRAM) devices. The design is motivated by modeling the effect of radiation particles striking hybrid complementary metal oxide semiconductor/spin based circuits, and the resistive behavior of SHE-MRAM devices via established and precise physics equations. The models developed are leveraged in the SPICE circuit simulator to verify the functionality of the proposed design. The proposed hardening technique is based on using feedback transistors, as well as increasing the radiation capacity of the sensitive nodes. Simulation results show that our proposed LUT circuit can achieve multiple node upset (MNU) tolerance with more than 38% and 60% power-delay product improvement as well as 26% and 50% reduction in device count compared to the previous energy-efficient radiation-hardened LUT designs. Finally, we have performed a process variation analysis showing that the MNU immunity of our proposed circuit is realized at the cost of increased susceptibility to transistor and MRAM variations compared to an unprotected LUT design.

A novel approach for evaluating acceptable intra-operative correction of lower limb alignment in femoral and tibial malunion using the deviation angle of the normal contralateral knee.

Science.gov (United States)

Wu, Chi-Chuan

2014-03-01

A simple and appropriate approach for evaluating an acceptable alignment of bone around the knee during operation has not yet been reported. Thirty-five men and 35 women presenting with nonunion or malunion of the unilateral femoral shaft were included in the first study. Using the standing scanograph, the contralateral normal lower extremity was measured to determine the normal deviation angle (DA) of the medial malleolus when the medial aspect of the knee was placed in the midline of the body. In the second study, the normal DA from individual patients was used as a reference to evaluate knee alignment during operation in 40 other patients presenting with distal femoral or proximal tibial nonunion or malunion. The clinical and knee functional outcomes of these 40 patients were investigated. The average normal DA was 4.2° in men and 6.0° in women (palignment was maintained in all 30 patients with fracture union. Satisfactory function of the knee was achieved in 28 patients (82%, palignment of bone around the knee during operation. Level IV, Case series. Copyright © 2012 Elsevier B.V. All rights reserved.

Public exposure from environmental release of radioactive material under normal operation of unit-1 Bushehr nuclear power plant

International Nuclear Information System (INIS)

Sohrabi, M.; Parsouzi, Z.; Amrollahi, R.; Khamooshy, C.; Ghasemi, M.

2013-01-01

Highlights: ► The unit-1 Bushehr nuclear power plant is a VVER type reactor with 1000 MWe power. ► Doses of public critical groups living around the plant were assessed under normal reactor operation conditions. ► PC-CREAM 98 computer code developed by the HPA was applied to assess the public doses. ► Doses are comparable with those in the FSAR, in the ER and doses monitored. ► The doses assessed are lower than the dose constraint of 0.1 mSv/y associated with the plant. - Abstract: The Unit-1 Bushehr Nuclear Power Plant (BNPP-1), constructed at the Hallileh site near Bushehr located at the coast of the Persian Gulf, Iran, is a VVER type reactor with 1000 MWe power. According to standard practices, under normal operation conditions of the plant, radiological assessment of atmospheric and aquatic releases to the environment and assessment of public exposures are considered essential. In order to assess the individual and collective doses of the critical groups of population who receive the highest dose from radioactive discharges into the environment (atmosphere and aquatic) under normal operation conditions, this study was conducted. To assess the doses, the PC-CREAM 98 computer code developed by the Radiation Protection Division of the Health Protection Agency (HPA; formerly called NRPB) was applied. It uses a standard Gaussian plume dispersion model and comprises a suite of models and data for estimation of the radiological impact assessments of routine and continuous discharges from an NPP. The input data include a stack height of 100 m annual radionuclides release of gaseous effluents from the stack and liquid effluents that are released from heat removal system, meteorological data from the Bushehr local meteorological station, and the data for agricultural products. To assess doses from marine discharges, consumption of sea fish, crustacean and mollusca were considered. According to calculation by PC-CREAM 98 computer code, the highest individual

Operational, control and protective system transient analyses of the closed-cycle GT-HTGR power plant

International Nuclear Information System (INIS)

Openshaw, F.L.; Chan, T.W.

1980-07-01

This paper presents a description of the analyses of the control/protective system preliminary designs for the gas turbine high-temperature gas-cooled reactor (GT-HTGR) power plant. The control system is designed to regulate reactor power, control electric load and turbine speed, control the temperature of the helium delivered to the turbines, and control thermal transients experienced by the system components. In addition, it provides the required control programming for startup, shutdown, load ramp, and other expected operations. The control system also handles conditions imposed on the system during upset and emergency conditions such as loop trip, reactor trip, or electrical load rejection

Upset due to a single particle caused propagated transients in a bulk CMOS microprocessor

International Nuclear Information System (INIS)

Leavy, J.F.; Hoffmann, L.F.; Shoran, R.W.; Johnson, M.T.

1991-01-01

This paper reports on data pattern advances observed in preset, single event upset (SEU) hardened clocked flip-flops, during static Cf-252 exposures on a bulk CMOS microprocessor, that were attributable to particle caused anomalous clock signals, or propagated transients. SPICE simulations established that particle strikes in the output nodes of a clock control logic flip-flop could produce transients of sufficient amplitude and duration to be accepted as legitimate pulses by clock buffers fed by the flip-flop's output nodes. The buffers would then output false clock pulses, thereby advancing the state of the present flip-flops. Masking the clock logic on one of the test chips made the flip-flop data advance cease, confirming the clock logic as the source of the SEU. By introducing N 2 gas, at reduced pressures, into the SEU test chamber to attenuate Cf-252 particle LET's, a 24-26 MeV-cm 2 /mg LET threshold was deduced. Subsequent tests, at the 88-inch cyclotron at Berkeley, established an LET threshold of 30 MeV-cm 2 /mg (283 MeV Cu at 0 degrees) for the generation of false clocks. Cyclotron SEU tests are considered definitive, while Cf-252 data usually is not. However, in this instance Cf-252 tests proved analytically useful, providing SEU characterization data that was both timely and inexpensive

Multiple cell upset cross-section modeling: A possible interpretation for the role of the ion energy-loss straggling and Auger recombination

Energy Technology Data Exchange (ETDEWEB)

Zebrev, G.I., E-mail: gizebrev@mephi.ru; Zemtsov, K.S.

2016-08-11

We found that the energy deposition fluctuations in the sensitive volumes may cause the multiple cell upset (MCU) multiplicity scatter in the nanoscale (with feature sizes less than 100 nm) memories. A microdosimetric model of the MCU cross-section dependence on LET is proposed. It was shown that ideally a staircase-shaped cross-section vs LET curve spreads due to the energy-loss straggling impact into a quasi-linear dependence with a slope depending on the memory cell area, the cell critical energy and efficiency of charge collection. This paper also presents a new model of the Auger recombination as a limiting process of the electron–hole charge yield, especially at the high-LET ion impact. A modified form of the MCU cross-section vs LET data interpolation is proposed, discussed and validated.

Multiple cell upset cross-section modeling: A possible interpretation for the role of the ion energy-loss straggling and Auger recombination

International Nuclear Information System (INIS)

Zebrev, G.I.; Zemtsov, K.S.

2016-01-01

We found that the energy deposition fluctuations in the sensitive volumes may cause the multiple cell upset (MCU) multiplicity scatter in the nanoscale (with feature sizes less than 100 nm) memories. A microdosimetric model of the MCU cross-section dependence on LET is proposed. It was shown that ideally a staircase-shaped cross-section vs LET curve spreads due to the energy-loss straggling impact into a quasi-linear dependence with a slope depending on the memory cell area, the cell critical energy and efficiency of charge collection. This paper also presents a new model of the Auger recombination as a limiting process of the electron–hole charge yield, especially at the high-LET ion impact. A modified form of the MCU cross-section vs LET data interpolation is proposed, discussed and validated.

Buckling resistance calculation of Guide Thimbles for the mechanical design of fuel assembly type PWR under normal reactor operating conditions

International Nuclear Information System (INIS)

Cruz, C.B.L.

1990-01-01

The calculations demonstrate the fulfillment of one of the mechanical design criteria for the Fuel Assembly Structure under normal reactor operating conditions. The calculations of stresses in the Guide Thimbles are performed with the aid of the program ANSYS. This paper contains program parameters and modelling of a typical Fuel Assembly for a Reactor similar to ANGRA II. (author)

Modeling the cool down of the primary heat transport system using shut down cooling system in normal operation and after events such as LOCA

International Nuclear Information System (INIS)

Icleanu, D.L.; Prisecaru, I.

2015-01-01

This paper aims at modeling the cooling of the primary heat transport system using shutdown cooling system (SDCS), for a CANDU 6 NPP in all operating modes, normal and abnormal (particularly in case of LOCA accident), using the Flowmaster calculation code. The modelling of heavy water flow through the shutdown cooling system and primary heat transport system was performed to determine the distribution of flows, pressure in various areas of the hydraulic circuit and the pressure loss corresponding to the components but also for the heat calculation of the heat exchangers related to the system. The results of the thermo-hydraulic analysis show that in all cases analyzed, normal operation and for LOCA accident regime, the performance requirements are confirmed by analysis

Preparation and Properties of Anisotropic Nano-crystalline NdFeB Powders Made by Hydrogen Decrepitation of Die Upsetting Magnets

Energy Technology Data Exchange (ETDEWEB)

Yi, P P; Lee, D; Yan, A R, E-mail: ypp@nimte.ac.cn [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

2011-01-01

Anisotropic nanocrystalline NdFeB powders were prepared by hydrogen decrepitation (HD) of die upsetting magnets. The effects of varying temperatures of HD on the microstructure and magnetic properties of the anisotropic NdFeB particles were studied. It shows that the powders which obtained by HD process at higher temperature were larger than that at lower temperature, and the HD powders show a well anisotropy at 723 K, the remanence (B{sub r}) was more than 12.46 kG, the maximum energy product ((BH){sub max}) was 19.06 MGOe, and the coercivity (H{sub cj}) was 7.2 kOe. The microstructure of the anisotropic powders revealed that with a reasonable HD temperature, the platelet grains were not destroyed. They were nearly 150-300 nm long and 30-50 nm wide. The results indicate that HD process was an effective way to prepare the anisotropic NdFeB powders.

Artificial neural network for research reactor safety status monitoring

International Nuclear Information System (INIS)

Varde, P.V.

2001-01-01

During reactor upset/abnormal conditions, emphasis is placed on plant operator's ability to quickly identify the problem and perform diagnosis and initiate recovery action to ensure safety of the plant. However, the reliability of human action is adversely affected at the time of crisis, due to the time stress and psychological factors. Availability of operational aids capable of monitoring the status of the plant and quickly identifying the deviation from normal operation is expected to significantly improve the operator reliability. Artificial Neural Network (based on Back Propagation Algorithm) has been developed and applied for reactor safety status monitoring, as part of an Operator Support System. ANN has been trained for 14 different plant states using 42 input symptom patterns. Recall tests performed on the ANN show that the system was able to identify the plant state with reasonable accuracy. (author)

Concept of the core for a small-to-medium-sized BWR that does not use control rods during normal operation

Energy Technology Data Exchange (ETDEWEB)

Nakadozono, N.; Ikegawa, T., E-mail: naoyuki.nakadozono.st@hitachi.com [Hitachi Ltd., Hitachi Research Lab., Ibaraki (Japan); Nishida, K. [Hitachi Works, Hitachi-GE Nuclear Energy Ltd., Hitachi-shi, Ibaraki (Japan)

2013-07-01

A small-to-medium-sized boiling water reactor (BWR) with a natural circulation system is being developed for countries where initial investment funds for construction are limited and electricity transmission networks have not been fully constructed. To lighten operators' work load, a core that does not use control rods during normal operation (control rod-free core) was developed by using a neutronics calculation system coupled with core flow evaluation. The control rod-free core had large core power fluctuation with conventional burnable poison design. The target of core power fluctuation was set to less than 10% and was achieved by optimization of burnable poison arrangement. (author)

Concept of the core for a small-to-medium-sized BWR that does not use control rods during normal operation

International Nuclear Information System (INIS)

Nakadozono, N.; Ikegawa, T.; Nishida, K.

2013-01-01

A small-to-medium-sized boiling water reactor (BWR) with a natural circulation system is being developed for countries where initial investment funds for construction are limited and electricity transmission networks have not been fully constructed. To lighten operators' work load, a core that does not use control rods during normal operation (control rod-free core) was developed by using a neutronics calculation system coupled with core flow evaluation. The control rod-free core had large core power fluctuation with conventional burnable poison design. The target of core power fluctuation was set to less than 10% and was achieved by optimization of burnable poison arrangement. (author)

Information Foraging in Nuclear Power Plant Control Rooms

International Nuclear Information System (INIS)

Boring, R.L.

2011-01-01

nformation foraging theory articulates the role of the human as an 'informavore' that seeks information and follows optimal foraging strategies (i.e., the 'information scent') to find meaningful information. This paper briefly reviews the findings from information foraging theory outside the nuclear domain and then discusses the types of information foraging strategies operators employ for normal and off-normal operations in the control room. For example, operators may employ a predatory 'wolf' strategy of hunting for information in the face of a plant upset. However, during routine operations, the operators may employ a trapping 'spider' strategy of waiting for relevant indicators to appear. This delineation corresponds to information pull and push strategies, respectively. No studies have been conducted to determine explicitly the characteristics of a control room interface that is optimized for both push and pull information foraging strategies, nor has there been empirical work to validate operator performance when transitioning between push and pull strategies. This paper explores examples of control room operators as wolves vs. spiders and con- cludes by proposing a set of research questions to investigate information foraging in control room settings.

Information Foraging in Nuclear Power Plant Control Rooms

Energy Technology Data Exchange (ETDEWEB)

R.L. Boring

2011-09-01

nformation foraging theory articulates the role of the human as an 'informavore' that seeks information and follows optimal foraging strategies (i.e., the 'information scent') to find meaningful information. This paper briefly reviews the findings from information foraging theory outside the nuclear domain and then discusses the types of information foraging strategies operators employ for normal and off-normal operations in the control room. For example, operators may employ a predatory 'wolf' strategy of hunting for information in the face of a plant upset. However, during routine operations, the operators may employ a trapping 'spider' strategy of waiting for relevant indicators to appear. This delineation corresponds to information pull and push strategies, respectively. No studies have been conducted to determine explicitly the characteristics of a control room interface that is optimized for both push and pull information foraging strategies, nor has there been empirical work to validate operator performance when transitioning between push and pull strategies. This paper explores examples of control room operators as wolves vs. spiders and con- cludes by proposing a set of research questions to investigate information foraging in control room settings.

Single Event Upset Analysis: On-orbit performance of the Alpha Magnetic Spectrometer Digital Signal Processor Memory aboard the International Space Station

Science.gov (United States)

Li, Jiaqiang; Choutko, Vitaly; Xiao, Liyi

2018-03-01

Based on the collection of error data from the Alpha Magnetic Spectrometer (AMS) Digital Signal Processors (DSP), on-orbit Single Event Upsets (SEUs) of the DSP program memory are analyzed. The daily error distribution and time intervals between errors are calculated to evaluate the reliability of the system. The particle density distribution of International Space Station (ISS) orbit is presented and the effects from the South Atlantic Anomaly (SAA) and the geomagnetic poles are analyzed. The impact of solar events on the DSP program memory is carried out combining data analysis and Monte Carlo simulation (MC). From the analysis and simulation results, it is concluded that the area corresponding to the SAA is the main source of errors on the ISS orbit. Solar events can also cause errors on DSP program memory, but the effect depends on the on-orbit particle density.

STUDY ON ENERGY EXCHANGE PROCESSES IN NORMAL OPERATION OF METRO ROLLING STOCK WITH REGENERATIVE BRAKING SYSTEMS

Directory of Open Access Journals (Sweden)

A. O. Sulym

2017-10-01

Full Text Available Purpose. The analysis of the existing studies showed that the increasing of energy efficiency of metro rolling stock becomes especially important and requires timely solutions. It is known that the implementation of regenerative braking systems on rolling stock will allow significantly solving this problem. It was proved that one of the key issues regarding the introduction of the above-mentioned systems is research on efficient use of electric energy of regenerative braking. The purpose of the work is to evaluate the amount of excessive electric power of regenerative braking under normal operation conditions of the rolling stock with regenerative braking systems for the analysis of the energy saving reserves. Methodology. Quantifiable values of electrical energy consumed for traction, returned to the contact line and dissipated in braking resistors (excessive energy are determined using results of experimental studies of energy exchange processes under normal operating conditions of metro rolling stock with regenerative systems. Statistical methods of data processing were applied as well. Findings. Results of the studies analysis of metro rolling stock operation under specified conditions in Sviatoshinsko-Brovarskaia line of KP «Kyiv Metro system» stipulate the following: 1 introduction of regenerative braking systems into the rolling stock allows to return about 17.9-23.2% of electrical energy consumed for traction to the contact line; 2 there are reserves for improving of energy efficiency of rolling stock with regenerative systems at the level of 20.2–29.9 % of electrical energy consumed for traction. Originality. For the first time, it is proved that the most significant factor that influences the quantifiable values of the electrical energy regeneration is a track profile. It is suggested to use coefficients which indicate the amount and reserves of unused (excessive electrical energy for quantitative evaluation. Studies on

The influence of operational conditions on radiation damage in JFET-input operational amplifiers

International Nuclear Information System (INIS)

Zheng Yuzhan; Wang Yiyuan; Chen Rui; Fei Wuxiong; Lu Wu; Ren Diyuan

2010-01-01

High- and low-dose-rate irradiation have been performed on JFET-input operational amplifiers (op-amps) with normal operational and zero biased conditions, respectively. The experimental results show that operational conditions have a great influence on the radiation effects and damage in JFET-input operational amplifiers. Under normal condition, the JFET-input op-amps have exhibited time-dependent effect (TDE); while they show enhanced low-dose-rate sensitivity (ELDRS) at zero biased condition. Compared with zero biased condition, the JFET-input op-amps would degrade more severely at normal condition for high-dose-rate irradiation; while for the low-dose-rate case, they have more degradation at normal condition. Irradiation would induce positive oxide-trapped charge and interface traps in bipolar transistors, which are the basic components in JFET-input op-amps. From the dependence of oxide trapped charge and interface traps on operational conditions, the degradation behavior is discussed. (authors)

Percutaneous transhepatic biliary drainage through the normal duct in patients with post-operative bile leakage

International Nuclear Information System (INIS)

Lee, Hyun; Kim, Young Hwan; Kim, Yong Joo

2004-01-01

To evaluate the technical feasibility and clinical efficacy of percutaneous transhepatic biliary drainage (PTBD) through the normal duct in patients with post-operative bile leakage. From January 1998 to December 2003, fourteen patients (male: 12, female: 2, mean age: 56) with biliary leak after laparoscopic cholecystectomy (n = 5), T-tube removal (n = 5), choledochojejunostomy due to small bowel perforation (n = 1), right lobectomy (n = 1), laparoscopic adrenalectomy (n = 1), and subtotal gastrectomy (n = 1) were treated by means of PTBD; this was performed with the two-step approach. The central bile duct was cannulated using a 21-G Chiba needle to map the intrahepatic biliary tree. An 8.5-F drainage catheter tip was positioned at the CBD after puncturing peripheral bile duct with an additional Chiba needle. We evaluated the technical feasibility, the procedure-related complications, clinical efficacy and the duration of catheter placement. PTBD of the normal duct with the two-step approach was successful in all but two cases. In these two cases, the two-step approach was failed due to the rapid disappearance of the targeted peripheral duct, and this was the result caused by biloportal fistula. PTBD was performed through the central bile duct in one patient, and through the remnant cystic duct in one patient. There were no procedure-related complications except for mild abdominal pain in seven patients. Bile leakage was demonstrated on cholangiogram in 10 of 14 patients; this occurred at the T-tube exit site (n = 4), cystic duct stump (n = 2), choledochojejunostomy site (n = 1), resection margin of liver (n = 1), caudate lobe (n = 1), and GB bed (n = 1). In 13 patients, the biliary leak stopped after drainage (mean duration: 32.1 days). In one patient, surgical management was performed one day after PTBD due to the excessive amount of bile leakage. PTBD is a technically feasible and clinically efficacious treatment for post-operative bile leakage, and it can

The differential radiological impact of plutonium recycle in the light-water reactor fuel cycle: effluent discharges during normal operation

International Nuclear Information System (INIS)

Bouville, A.; Guetat, P.; Jones, J.A.; Kelly, G.N.; Legrand, J.; White, I.F.

1980-01-01

The radiological impact of a light-water reactor fuel cycle utilizing enriched uranium fuel may be altered by the recycle of plutonium. Differences in impact may arise during various operations in the fuel cycle: those which arise from effluents discharged during normal operation of the various installations comprising the fuel cycle are evaluated in this study. The differential radiological impact on the population of the European Communities (EC) of effluents discharged during the recycling of 10 tonnes of fissile plutonium metal is evaluated. The contributions from each stage of the fuel cycle, i.e. fuel fabrication, reactor operation and fuel reprocessing and conversion, are identified. Separate consideration is given to airborne and liquid effluents and account is taken of a wide range of environmental conditions, representative of the EC, in estimating the radiological impact. The recycle of plutonium is estimated to result in a reduction in the radiological impact from effluents of about 30% of that when using enriched uranium fuel

Normal return and efficient operation of the electric grid monopolies; Normalavkastning og effektiv drift for nettmonopolene

Energy Technology Data Exchange (ETDEWEB)

Skjeret, Frode Andre

2001-07-01

This report deals with the size of the risk premium for electric grid operation in Norway. The size of the companies' risk premium must reflect the market requirements on return compensation (for normal investment risk), adjusted for the return risk for this type of enterprise. The return risk of the grid companies is discussed using two approaches, one theoretical and one empirical. This implies an empirical analysis of comparable foreign companies and an examination of the Norwegian regulatory regime. It is concluded that the regulatory authority is using too small an estimate for the risk premium when determining the capital income of the Norwegian utilities. The report also discusses the principles for valuation of the capital base.

Neutron-induced Single Event Upset on the RPC front-end chips for the CMS experiment

Energy Technology Data Exchange (ETDEWEB)

Abbrescia, M.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Altieri, S.; Belli, G.; Bruno, G.; Guida, R.; Merlo, M.; Ratti, S.P.; Riccardi, C.; Torre, P.; Vitulo, P. E-mail: paolo.vitulo@pv.infn.it; De Bari, A.; Manera, S

2002-05-21

Neutrons from a reactor and from a cyclotron have been used to characterise the CMS Resistive Plate Chambers (RPCs) front-end chip to neutron-induced damaging events. Single Event Upset (SEU) cross-sections have been measured up to 60 MeV for different chip thresholds. Tests at a reactor were done with an integrated fast (E{sub n}>3 MeV) neutron fluence of 1.7x10{sup 10} cm{sup -2} and a thermal neutron fluence of 9.5x10{sup 11} cm{sup -2}. High-energy neutrons from a cyclotron were used up to a fluence of 10{sup 12} cm{sup -2}. Data indicate the existence of a chip SEU sensitivity already at thermal energy and a saturated SEU cross-section from 3 to 60 MeV. Values of the SEU cross-sections from the thermal run well agree with those obtained by another CMS group that uses the same technology (0.8 {mu}m BiCMOS) though with different architecture. Cross-sections obtained with fast neutrons (from 3 MeV to about 10 MeV) are consistently higher by one order of magnitude compared to the thermal one. The average time between consecutive SEU events in each chip of the CMS barrel RPCs can be estimated to be 1 h.

Helicon normal modes in Proto-MPEX

Science.gov (United States)

Piotrowicz, P. A.; Caneses, J. F.; Green, D. L.; Goulding, R. H.; Lau, C.; Caughman, J. B. O.; Rapp, J.; Ruzic, D. N.

2018-05-01

The Proto-MPEX helicon source has been operating in a high electron density ‘helicon-mode’. Establishing plasma densities and magnetic field strengths under the antenna that allow for the formation of normal modes of the fast-wave are believed to be responsible for the ‘helicon-mode’. A 2D finite-element full-wave model of the helicon antenna on Proto-MPEX is used to identify the fast-wave normal modes responsible for the steady-state electron density profile produced by the source. We also show through the simulation that in the regions of operation in which core power deposition is maximum the slow-wave does not deposit significant power besides directly under the antenna. In the case of a simulation where a normal mode is not excited significant edge power is deposited in the mirror region. ).

Modeling operators' emergency response time for chemical processing operations.

Science.gov (United States)

Murray, Susan L; Harputlu, Emrah; Mentzer, Ray A; Mannan, M Sam

2014-01-01

Operators have a crucial role during emergencies at a variety of facilities such as chemical processing plants. When an abnormality occurs in the production process, the operator often has limited time to either take corrective actions or evacuate before the situation becomes deadly. It is crucial that system designers and safety professionals can estimate the time required for a response before procedures and facilities are designed and operations are initiated. There are existing industrial engineering techniques to establish time standards for tasks performed at a normal working pace. However, it is reasonable to expect the time required to take action in emergency situations will be different than working at a normal production pace. It is possible that in an emergency, operators will act faster compared to a normal pace. It would be useful for system designers to be able to establish a time range for operators' response times for emergency situations. This article develops a modeling approach to estimate the time standard range for operators taking corrective actions or following evacuation procedures in emergency situations. This will aid engineers and managers in establishing time requirements for operators in emergency situations. The methodology used for this study combines a well-established industrial engineering technique for determining time requirements (predetermined time standard system) and adjustment coefficients for emergency situations developed by the authors. Numerous videos of workers performing well-established tasks at a maximum pace were studied. As an example, one of the tasks analyzed was pit crew workers changing tires as quickly as they could during a race. The operations in these videos were decomposed into basic, fundamental motions (such as walking, reaching for a tool, and bending over) by studying the videos frame by frame. A comparison analysis was then performed between the emergency pace and the normal working pace operations

Modelling of innovative SANEX process mal-operations

International Nuclear Information System (INIS)

McLachlan, F.; Taylor, R.; Whittaker, D.; Woodhead, D.; Geist, A.

2016-01-01

The innovative (i-) SANEX process for the separation of minor actinides from PUREX highly active raffinate is expected to employ a solvent phase comprising 0.2 M TODGA with 5 v/v% 1-octanol in an inert diluent. An initial extract / scrub section would be used to extract trivalent actinides and lanthanides from the feed whilst leaving other fission products in the aqueous phase, before the loaded solvent is contacted with a low acidity aqueous phase containing a sulphonated bis-triazinyl pyridine ligand (BTP) to effect a selective strip of the actinides, so yielding separate actinide (An) and lanthanide (Ln) product streams. This process has been demonstrated in lab scale trials at Juelich (FZJ). The SACSESS (Safety of Actinide Separation processes) project is focused on the evaluation and improvement of the safety of such future systems. A key element of this is the development of an understanding of the response of a process to upsets (mal-operations). It is only practical to study a small subset of possible mal-operations experimentally and consideration of the majority of mal-operations entails the use of a validated dynamic model of the process. Distribution algorithms for HNO_3, Am, Cm and the lanthanides have been developed and incorporated into a dynamic flowsheet model that has, so far, been configured to correspond to the extract-scrub section of the i-SANEX flowsheet trial undertaken at FZJ in 2013. Comparison is made between the steady state model results and experimental results. Results from modelling of low acidity and high temperature mal-operations are presented. (authors)

nth roots of normal contractions

International Nuclear Information System (INIS)

Duggal, B.P.

1992-07-01

Given a complex separable Hilbert space H and a contraction A on H such that A n , n≥2 some integer, is normal it is shown that if the defect operator D A = (1 - A * A) 1/2 is of the Hilbert-Schmidt class, then A is similar to a normal contraction, either A or A 2 is normal, and if A 2 is normal (but A is not) then there is a normal contraction N and a positive definite contraction P of trace class such that parallel to A - N parallel to 1 = 1/2 parallel to P + P parallel to 1 (where parallel to · parallel to 1 denotes the trace norm). If T is a compact contraction such that its characteristics function admits a scalar factor, if T = A n for some integer n≥2 and contraction A with simple eigen-values, and if both T and A satisfy a ''reductive property'', then A is a compact normal contraction. (author). 16 refs

The calculating methods of the release of airborne radionuclides to environment during the normal operation of a module high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Liu Yuanzhong

1993-01-01

The calculations of the release of radionuclides to environment are the basis of environmental impact assessment during the normal operation of a module high temperature gas-cooled reactor of the Institute of Nuclear Energy Technology, Tsinghua University, China. According to the features of the reactor it is pointed out that only five sources of the airborne radioactive materials released to environment are important. They are: (1) the activation of the air in the reactor cavity; (2) the escape from the primary coolant systems; (3) the release of radioactively contaminated helium from storage tanks; (4) the release of radioactively contaminated helium from the gas evacuation system of fuel load and unload system; (5) the leakage of the vapour from water-steam loop. In accordance with five release sources the calculating methods of radionuclides released to environment are worked out respectively and the respective calculating formulas are derived for the normal operation of the reactor

Molecular monitoring of equine joint homeostasis

NARCIS (Netherlands)

de Grauw, J.C.

2010-01-01

Chronic joint disorders are a major cause of impaired mobility and loss of quality of life in both humans and horses. Regardless of the primary insult, any joint disorder is characterized by an upset in normal joint homeostasis, the balance between tissue anabolism and catabolism that is normally

The consequences of non-normality

International Nuclear Information System (INIS)

Hip, I.; Lippert, Th.; Neff, H.; Schilling, K.; Schroers, W.

2002-01-01

The non-normality of Wilson-type lattice Dirac operators has important consequences - the application of the usual concepts from the textbook (hermitian) quantum mechanics should be reconsidered. This includes an appropriate definition of observables and the refinement of computational tools. We show that the truncated singular value expansion is the optimal approximation to the inverse operator D -1 and we prove that due to the γ 5 -hermiticity it is equivalent to γ 5 times the truncated eigenmode expansion of the hermitian Wilson-Dirac operator

Fusion and normalization to enhance anomaly detection

Science.gov (United States)

Mayer, R.; Atkinson, G.; Antoniades, J.; Baumback, M.; Chester, D.; Edwards, J.; Goldstein, A.; Haas, D.; Henderson, S.; Liu, L.

2009-05-01

This study examines normalizing the imagery and the optimization metrics to enhance anomaly and change detection, respectively. The RX algorithm, the standard anomaly detector for hyperspectral imagery, more successfully extracts bright rather than dark man-made objects when applied to visible hyperspectral imagery. However, normalizing the imagery prior to applying the anomaly detector can help detect some of the problematic dark objects, but can also miss some bright objects. This study jointly fuses images of RX applied to normalized and unnormalized imagery and has a single decision surface. The technique was tested using imagery of commercial vehicles in urban environment gathered by a hyperspectral visible/near IR sensor mounted in an airborne platform. Combining detections first requires converting the detector output to a target probability. The observed anomaly detections were fitted with a linear combination of chi square distributions and these weights were used to help compute the target probability. Receiver Operator Characteristic (ROC) quantitatively assessed the target detection performance. The target detection performance is highly variable depending on the relative number of candidate bright and dark targets and false alarms and controlled in this study by using vegetation and street line masks. The joint Boolean OR and AND operations also generate variable performance depending on the scene. The joint SUM operation provides a reasonable compromise between OR and AND operations and has good target detection performance. In addition, new transforms based on normalizing correlation coefficient and least squares generate new transforms related to canonical correlation analysis (CCA) and a normalized image regression (NIR). Transforms based on CCA and NIR performed better than the standard approaches. Only RX detection of the unnormalized of the difference imagery in change detection provides adequate change detection performance.

B ampersand W PWR advanced control system algorithm development

International Nuclear Information System (INIS)

Winks, R.W.; Wilson, T.L.; Amick, M.

1992-01-01

This paper discusses algorithm development of an Advanced Control System for the B ampersand W Pressurized Water Reactor (PWR) nuclear power plant. The paper summarizes the history of the project, describes the operation of the algorithm, and presents transient results from a simulation of the plant and control system. The history discusses the steps in the development process and the roles played by the utility owners, B ampersand W Nuclear Service Company (BWNS), Oak Ridge National Laboratory (ORNL), and the Foxboro Company. The algorithm description is a brief overview of the features of the control system. The transient results show that operation of the algorithm in a normal power maneuvering mode and in a moderately large upset following a feedwater pump trip

CFD Analysis of Random Turbulent Flow Load in Steam Generator of APR1400 Under Normal Operation Condition

International Nuclear Information System (INIS)

Lim, Sang Gyu; You, Sung Chang; Kim, Han Gon

2011-01-01

Regulatory guide 1.20 revision 3 of the Nuclear Regulatory Committee (NRC) modifies guidance for vibration assessments of reactor internals and steam generator internals. The new guidance requires applicants to provide a preliminary analysis and evaluation of the design and performance of a facility, including the safety margins of during normal operation and transient conditions anticipated during the life of the facility. Especially, revision 3 require rigorous assessments of adverse flow effects in the steam dryer cased by flow-excited acoustic and structural resonances such as the abnormality from power-uprated BWR cases. For two nearly identical nuclear power plants, the steam system of one BWR plant experienced failure of steam dryers and the main steam system components when steam flow was increased by 16 percent for extended power uprate (EPU). The mechanisms of those failures have revealed that a small adverse flow changing from the prototype condition induced severe flow-excited acoustic and structural resonances, leading to structural failures. In accordance with the historical background, therefore, potential adverse flow effects should be evaluated rigorously for steam generator internals in both BWR and Pressurized Water Reactor (PWR). The Advanced Power Reactor 1400 (APR1400), an evolutionary light water reactor, increased the power by 7.7 percent from the design of the 'Valid Prototype', System80+. Thus, reliable evaluations of potential adverse flow effects on the steam generator of APR1400 are necessary according to the regulatory guide. This paper is part of the computational fluid dynamics (CFD) analysis results for evaluation of the adverse flow effect for the steam generator internals of APR1400, including a series of sensitivity analyses to enhance the reliability of CFD analysis and an estimation the effect of flow loads on the internals of the steam generator under normal operation conditions

Device for absorbing the axial forces occurring on the fuel assemblies during operation of a nuclear reactor

International Nuclear Information System (INIS)

Sankovich, M.F.

1978-01-01

The fuel assemblies consisting of rod-shaped fuel rods stand on a grid plate. Opposite the projections of the upper grid plate mounted on a support barrel the fuel assemblies are elastically supported in order to compensate the mechanical vibrations and thermal expansions occurring during operation. This is achieved by combined bending and torsion springs bridging the distance between projections and fuel assembly end pieces. The bending and torsion springs consist of a bending arm, a torsion piece, and another bending arm being deflected by 90 0 and provided at the end with an upsetting. Each spring consists of round stock. In order to increase the flexibility one of the bending arms is designed conically or stepped. (DG) [de

An approach toward estimating the safety significance of normal and abnormal operating procedures in nuclear power plants

International Nuclear Information System (INIS)

Grant, T.F.; Harris, M.S.

1989-01-01

The Nuclear Regulatory Commission's TMI Action Plan calls for a long-term plan to upgrade operating procedures in nuclear power plants. The scope of Generic Issue Human Factors 4.4, which stems from this requirement, includes the recommendation of improvements in nuclear power plant normal and abnormal operating procedures (NOPs and AOPs) and the implementation of appropriate regulatory action. This paper will describe the objectives, methodologies, and results of a Battelle-conducted value impact assessment to determine the costs and benefits of having the NRC implement regulatory action that would specify requirements for the preparation of acceptable NOPs and AOPs by the Commission's nuclear power plant licensees. The results of this value impact assessment are expressed in terms of ten cost/benefit attributes that can be affected by the NRC regulatory action. Five of these attributes require the calculation of change in public risk that could be expected to result from the action which, in this case, required determining the safety significance of NOPs and AOPs. In order to estimate this safety significance, a multi-step methodology was created that relies on an existing Probabilistic Risk Assessment (PRA) to provide a quantitative framework for modeling the role of operating procedures. The purpose of this methodology is to determine what impact the improvement of NOPs and AOPs would have on public health and safety

DOSEFU: Computer application for dose calculation and effluent management in normal operation

International Nuclear Information System (INIS)

Martin Garcia, J. E.; Gonzalvo Manovel, A.; Revuelta Garcia, L.

2002-01-01

DOSEFU is a computer application on Windows that develops the methodology of nuclear power plant Exterior Dose Calculation Manuals (Manuals de Calculo de Dosis al Exterior-MACADE) for calculating doses in normal operation caused by radioactive liquid and gaseous effluents, for the purpose of enforcing the new Spanish Regulation on Health Protection against Ionizing Radiations, Royal Decree 783/2001 resulting from transposition of Directive 96/29/Euratom whereby the basic rules regarding health protection of workers and the population against risks resulting from ionizing radiations are established. In addition to making dose calculations, DOSEFU generates, on a magnetic support, the information regarding radioactive liquid and gaseous effluents that plants must periodically send to the CSN (ELGA format). The computer application has been developed for the specific case of Jose Cabrera NPP, which is called DOEZOR. This application can be easily implemented in any other nuclear or radioactive facility. The application is user-friendly, as the end user inputs data and executes the different modules through keys and dialogue boxes that are enabled by clicking on the mouse (see figures 2, 3, 4 and 5 ), The application runs under Windows 95. Digital Visual Fortran has been used as the development program, as this does not require additional libraries (DLLs), it can be installed in any computer without affecting other programs that are already installed. (Author)

Laboratory determination of normal operating flow rates with enlarged outlet fittings -- BDF reactors

Energy Technology Data Exchange (ETDEWEB)

Waters, E.D.

1960-02-02

Experiments have been conducted in the Hydraulics Laboratory, at the request of IPD`s Mechanical Development-A Operation, to determine the energy losses of various enlarged outlet fitting combinations. These experiments were conducted an steady state runs and allow the determination of the normal operating point (flow rate) of a reactor process channel under selected conditions of front header pressure and fuel charge. No attempt is made to make a mechanical or economic evaluation of the particular fitting combinations, although observations were noted which might bear on this evaluation. It is very important for the reader to bear in mind that changing outlet fittings will definitely affect the reactor tube power limits and outlet vater temperature limits. The size of the outlet fittings largely determines the present outlet temperature limits of the old reactors. The flow characteristics of these present fittings cause some degree of pressurization to suppress boiling on the fuel charge and also cause dual Panellit trip protection for certain flow changes and for power surges. Enlargement of the outlet fittings may actually reduce the allowable outlet coolant temperature limits. Since these effects cannot be determined on the apparatus used in these experiments, a complete discussion of this point is not included in this report. However, the seriousness of these effects should be known and carefully analyzed before a final selection of enlarged outlet fittings in made. This report will be one of a series. New reports in the series will be issued as data are obtained for other such outlet fitting combinations or for new concepts of outlet fitting assemblies such as the new nozzle being developed by C. E. Trantz for use on F-reactor stuck gunbarrel tubes.

Operating principle of Soft Open Points for electrical distribution network operation

International Nuclear Information System (INIS)

Cao, Wanyu; Wu, Jianzhong; Jenkins, Nick; Wang, Chengshan; Green, Timothy

2016-01-01

Highlights: • Two control modes were developed for a B2B VSCs based SOP. • The SOP operating principle was investigated under various network conditions. • The performance of the SOP using two control modes was analyzed. - Abstract: Soft Open Points (SOPs) are power electronic devices installed in place of normally-open points in electrical power distribution networks. They are able to provide active power flow control, reactive power compensation and voltage regulation under normal network operating conditions, as well as fast fault isolation and supply restoration under abnormal conditions. Two control modes were developed for the operation of an SOP, using back-to-back voltage-source converters (VSCs). A power flow control mode with current control provides independent control of real and reactive power. A supply restoration mode with a voltage controller enables power supply to isolated loads due to network faults. The operating principle of the back-to-back VSCs based SOP was investigated under both normal and abnormal network operating conditions. Studies on a two-feeder medium-voltage distribution network showed the performance of the SOP under different network-operating conditions: normal, during a fault and post-fault supply restoration. During the change of network operating conditions, a mode switch method based on the phase locked loop controller was used to achieve the transitions between the two control modes. Hard transitions by a direct mode switching were noticed unfavourable, but seamless transitions were obtained by deploying a soft cold load pickup and voltage synchronization process.

Hardened Flip-Flop Optimized for Subthreshold Operation Heavy Ion Characterization of a Radiation

Directory of Open Access Journals (Sweden)

Eric Bozeman

2012-05-01

Full Text Available A novel Single Event Upset (SEU tolerant flip-flop design is proposed, which is well suited for very-low power electronics that operate in subthreshold ( < Vt ≈ 500 mV. The proposed flip-flop along with a traditional (unprotected flip-flop, a Sense-Amplifier-based Rad-hard Flip-Flop (RSAFF and a Dual Interlocked storage Cell (DICE flip-flop were all fabricated in MIT Lincoln Lab’s XLP 0.15 μm fully-depleted SOI CMOS technology—a process optimized for subthreshold operation. At the Cyclotron Institute at Texas A&M University, all four cells were subjected to heavy ion characterization in which the circuits were dynamically updated with alternating data and then checked for SEUs at both subthreshold (450 mV and superthreshold (1.5 V levels. The proposed flip-flop never failed, while the traditional and DICE designs did demonstrate faulty behavior. Simulations were conducted with the XLP process and the proposed flip-flop provided an improved energy delay product relative to the other non-faulty rad-hard flip-flop at subthreshold voltage operation. According to the XLP models operating in subthreshold at 250 mV, performance was improved by 31% and energy consumption was reduced by 27%.

The impact of meal timing on performance, sleepiness, gastric upset, and hunger during simulated night shift.

Science.gov (United States)

Grant, Crystal Leigh; Dorrian, Jillian; Coates, Alison Maree; Pajcin, Maja; Kennaway, David John; Wittert, Gary Allen; Heilbronn, Leonie Kaye; Vedova, Chris Della; Gupta, Charlotte Cecilia; Banks, Siobhan

2017-10-07

This study examined the impact of eating during simulated night shift on performance and subjective complaints. Subjects were randomized to eating at night (n=5; 23.2 ± 5.5 y) or not eating at night (n=5; 26.2 ± 6.4 y). All participants were given one sleep opportunity of 8 h (22:00 h-06:00 h) before transitioning to the night shift protocol. During the four days of simulated night shift participants were awake from 16:00 h-10:00 h with a daytime sleep of 6 h (10:00 h-16:00 h). In the simulated night shift protocol, meals were provided at ≈0700 h, 1900 h and 0130 h (eating at night); or ≈0700 h, 0930 h, 1410 h and 1900 h (not eating at night). Subjects completed sleepiness, hunger and gastric complaint scales, a Digit Symbol Substitution Task and a 10-min Psychomotor Vigilance Task. Increased sleepiness and performance impairment was evident in both conditions at 0400 h (phunger and a small but significant elevation in stomach upset across the night (p<0.026). Eating at night was associated with elevated bloating on night one, which decreased across the protocol. Restricting food intake may limit performance impairments at night. Dietary recommendations to improve night-shift performance must also consider worker comfort.

Single event effects and performance predictions for space applications of RISC processors

International Nuclear Information System (INIS)

Kimbrough, J.R.; Colella, N.J.; Denton, S.M.; Shaeffer, D.L.; Shih, D.; Wilburn, J.W.; Coakley, P.G.; Casteneda, C.; Koga, R.; Clark, D.A.; Ullmann, J.L.

1994-01-01

Proton and ion Single Event Phenomena (SEP) tests were performed on 32-b processors including R3000A's from all commercial manufacturers along with the Performance PR3400 family, Integrated Device Technology Inc. 79R3081, LSI Logic Corporation LR33000HC, and Intel i80960MX parts. The microprocessors had acceptable upset rates for operation in a low earth orbit or a lunar mission such as CLEMENTINE with a wide range in proton total dose failure. Even though R3000A devices are 60% smaller in physical area than R3000 devices, there was a 340% increase in device Single Event Upset (SEU) cross section. Software tests of varying complexity demonstrate that registers and other functional blocks using register architecture dominate the cross section. The current approach of giving a single upset cross section can lead to erroneous upset rates depending on the application software

New operator assistance features in the CMS Run Control System

Science.gov (United States)

Andre, J.-M.; Behrens, U.; Branson, J.; Brummer, P.; Chaze, O.; Cittolin, S.; Contescu, C.; Craigs, B. G.; Darlea, G.-L.; Deldicque, C.; Demiragli, Z.; Dobson, M.; Doualot, N.; Erhan, S.; Fulcher, J. R.; Gigi, D.; Gładki, M.; Glege, F.; Gomez-Ceballos, G.; Hegeman, J.; Holzner, A.; Janulis, M.; Jimenez-Estupiñán, R.; Masetti, L.; Meijers, F.; Meschi, E.; Mommsen, R. K.; Morovic, S.; O'Dell, V.; Orsini, L.; Paus, C.; Petrova, P.; Pieri, M.; Racz, A.; Reis, T.; Sakulin, H.; Schwick, C.; Simelevicius, D.; Vougioukas, M.; Zejdl, P.

2017-10-01

During Run-1 of the LHC, many operational procedures have been automated in the run control system of the Compact Muon Solenoid (CMS) experiment. When detector high voltages are ramped up or down or upon certain beam mode changes of the LHC, the DAQ system is automatically partially reconfigured with new parameters. Certain types of errors such as errors caused by single-event upsets may trigger an automatic recovery procedure. Furthermore, the top-level control node continuously performs cross-checks to detect sub-system actions becoming necessary because of changes in configuration keys, changes in the set of included front-end drivers or because of potential clock instabilities. The operator is guided to perform the necessary actions through graphical indicators displayed next to the relevant command buttons in the user interface. Through these indicators, consistent configuration of CMS is ensured. However, manually following the indicators can still be inefficient at times. A new assistant to the operator has therefore been developed that can automatically perform all the necessary actions in a streamlined order. If additional problems arise, the new assistant tries to automatically recover from these. With the new assistant, a run can be started from any state of the sub-systems with a single click. An ongoing run may be recovered with a single click, once the appropriate recovery action has been selected. We review the automation features of CMS Run Control and discuss the new assistant in detail including first operational experience.

New Operator Assistance Features in the CMS Run Control System

Energy Technology Data Exchange (ETDEWEB)

Andre, J.M.; et al.

2017-11-22

During Run-1 of the LHC, many operational procedures have been automated in the run control system of the Compact Muon Solenoid (CMS) experiment. When detector high voltages are ramped up or down or upon certain beam mode changes of the LHC, the DAQ system is automatically partially reconfigured with new parameters. Certain types of errors such as errors caused by single-event upsets may trigger an automatic recovery procedure. Furthermore, the top-level control node continuously performs cross-checks to detect sub-system actions becoming necessary because of changes in configuration keys, changes in the set of included front-end drivers or because of potential clock instabilities. The operator is guided to perform the necessary actions through graphical indicators displayed next to the relevant command buttons in the user interface. Through these indicators, consistent configuration of CMS is ensured. However, manually following the indicators can still be inefficient at times. A new assistant to the operator has therefore been developed that can automatically perform all the necessary actions in a streamlined order. If additional problems arise, the new assistant tries to automatically recover from these. With the new assistant, a run can be started from any state of the sub-systems with a single click. An ongoing run may be recovered with a single click, once the appropriate recovery action has been selected. We review the automation features of CMS Run Control and discuss the new assistant in detail including first operational experience.

Spent Nuclear Fuel (SNF) Startup Plan to Operations

International Nuclear Information System (INIS)

GREGORY, J.R.

2000-01-01

This plan defines the approach that will be used to ensure the transition from initial startup to normal operations of the SNF operations--are performed in a safe, controlled, and deliberate manner. It provides a phased approach that bridges the operations between the completion of the ORR and the return to normal operations. This plan includes management oversight and administrative controls to be implemented and then reduced in a controlled manner until normal operations are authorized by SNF Management

Nuclear power plant operating personnel training for normal and accident situations

International Nuclear Information System (INIS)

Dufrene, C.

1995-01-01

Training system of reactor operating staff in France for maximum safety is discussed. The structure of the training program consists of three levels, initial training in each aspect of operations job functions, with systematic refresher training sessions; the principles at global team skills; the range of skills required for unit operation. (N.T.). 1 fig

Normal people working in normal organizations with normal equipment: system safety and cognition in a mid-air collision.

Science.gov (United States)

de Carvalho, Paulo Victor Rodrigues; Gomes, José Orlando; Huber, Gilbert Jacob; Vidal, Mario Cesar

2009-05-01

A fundamental challenge in improving the safety of complex systems is to understand how accidents emerge in normal working situations, with equipment functioning normally in normally structured organizations. We present a field study of the en route mid-air collision between a commercial carrier and an executive jet, in the clear afternoon Amazon sky in which 154 people lost their lives, that illustrates one response to this challenge. Our focus was on how and why the several safety barriers of a well structured air traffic system melted down enabling the occurrence of this tragedy, without any catastrophic component failure, and in a situation where everything was functioning normally. We identify strong consistencies and feedbacks regarding factors of system day-to-day functioning that made monitoring and awareness difficult, and the cognitive strategies that operators have developed to deal with overall system behavior. These findings emphasize the active problem-solving behavior needed in air traffic control work, and highlight how the day-to-day functioning of the system can jeopardize such behavior. An immediate consequence is that safety managers and engineers should review their traditional safety approach and accident models based on equipment failure probability, linear combinations of failures, rules and procedures, and human errors, to deal with complex patterns of coincidence possibilities, unexpected links, resonance among system functions and activities, and system cognition.

Monitoring of operating processes

International Nuclear Information System (INIS)

Barry, R.F.

1981-01-01

Apparatus is described for monitoring the processes of a nuclear reactor to detect off-normal operation of any process and for testing the monitoring apparatus. The processes are evaluated by response to their paramters, such as temperature, pressure, etc. The apparatus includes a pair of monitoring paths or signal processing units. Each unit includes facilities for receiving on a time-sharing basis, a status binary word made up of digits each indicating the status of a process, whether normal or off-normal, and test-signal binary words simulating the status binary words. The status words and test words are processed in succession during successive cycles. During each cycle, the two units receive the same status word and the same test word. The test words simulate the status words both when they indicate normal operation and when they indicate off-normal operation. Each signal-processing unit includes a pair of memories. Each memory receives a status word or a test word, as the case may be, and converts the received word into a converted status word or a converted test word. The memories of each monitoring unit operate into a non-coincidence which signals non-coincidence of the converted word out of one memory of a signal-processing unit not identical to the converted word of the other memory of the same unit

Development of Single-Event Upset hardened programmable logic devices in deep submicron CMOS; Developpement de circuits logiques programmables resistants aux aleas logiques en technologie CMOS submicrometrique

Energy Technology Data Exchange (ETDEWEB)

Bonacini, S

2007-11-15

The electronics associated to the particle detectors of the Large Hadron Collider (LHC), under construction at CERN, will operate in a very harsh radiation environment. Commercial Off-The-Shelf (COTS) components cannot be used in the vicinity of particle collision due to their poor radiation tolerance. This thesis is a contribution to the effort to cover the need for radiation-tolerant SEU-robust (Single Event Upset) programmable components for application in high energy physics experiments. Two components are under development: a Programmable Logic Device (PLD) and a Field-Programmable Gate Array (FPGA). The PLD is a fuse-based, 10-input, 8-I/O general architecture device in 0.25 {mu}m CMOS technology. The FPGA under development is a 32*32 logic block array, equivalent to {approx} 25 k gates, in 0.13 {mu}m CMOS. The irradiation test results obtained in the CMOS 0.25 {mu}m technology demonstrate good robustness of the circuit up to an LET (Linear Energy Transfer) of 79.6 cm{sup 2}*MeV/mg, which make it suitable for the target environment. The CMOS 0.13 {mu}m circuit has showed robustness to an LET of 37.4 cm{sup 2}*MeV/mg in the static test mode and has increased sensitivity in the dynamic test mode. This work focused also on the research for an SEU-robust register in both the mentioned technologies. The SEU-robust register is employed as a user data flip-flop in the FPGA and PLD designs and as a configuration cell as well in the FPGA design.

The State of the Art in Cold Forging Lubrication

DEFF Research Database (Denmark)

Bay, Niels

1994-01-01

The manufature of components in steel, aluminium and copper alloys by cold forging production has increased ever since the 1950's. Typical processes are forward rod extrusion and backward can extrusion, upsetting, ironing, tube extrusion and radial extrusion. The tribological conditions in cold...... forging are extremely severe due to large surface expansion and normal pressure in the tool/workpiece interface combined with elevated tool temperatures. Except for the more simple cold forging operations successful production therefore requires advanced lubrication systems. The present paper gives...... a detailed description of the state of art for lubricant systems for cold forging of C-steels and low alloy steels as well as aluminium alloys including all the basic operations such as cleaning of the slugs, application of eventual conversion coating and lubrication. As regards cold forging of steel...

When and How to Take Antibiotics

Science.gov (United States)

... bacterial balance, it may cause stomach upsets, diarrhea, vaginal infections, or other problems. If you take antibiotics unnecessarily ... before taking antibiotics? Antibiotics often lead to a vaginal yeast infection. Because antibiotics kill the normal bacteria in the ...

Review of construction criteria for nuclear fuels under normal operation and anticipated operational occurrences - a literature study; Oeversyn av konstruktionskriterier foer kaernbraensle under normaldrift och foervaentade driftsstoerningar - en litteraturstudie

Energy Technology Data Exchange (ETDEWEB)

Rudling, P. [Advanced Nuclear Technology, Uppsala (Sweden)

1999-06-01

General Design Criteria 10, GDC 10, in the Code of Federal Regulation Part 50 of Nuclear Regulatory Commission specifies that the fuel assembly including the fuel rod may not be damaged during normal operation and anticipated operational occurrences. No damaged, means that the fuel rods do not fail, that fuel rod and assembly dimensions remain within operational tolerances, and that functional capabilities are not reduced below those assumed in the safety analysis. This objective is given by GDC 10, and the design limits that are required to accomplish this objective are called Specified Acceptable Fuel Design Limits, SAFDLs. The SAFDLs are specified in Standard Review Plan, SRP, chapter 4.2. This report summarises and analyses published open data that are relevant for the below-specified SAFDLs. It also summarises the current view of NRC on the discussed SAFDLs as well as the margin towards fuel failure of the SAFDLs. The following SAFDLs are discussed herein: Avoidance of fuel centre melting; Avoidance of liftoff; Maximum cladding creep deformation; Avoidance of cladding collapse; Maximum fretting; Maximum dimensional changes; Maximum stresses; Maximum fatigue stresses; Maximum oxide thickness; Maximum hydrogen content; Avoidance of PCI - failures.

Vision for cross-layer optimization to address the dual challenges of energy and reliability

Energy Technology Data Exchange (ETDEWEB)

Quinn, Heather M [Los Alamos National Laboratory; Dehon, Andre [U. PENN; Carter, Nicholas P [INTEL

2009-01-01

We are rapidly approaching an inflection point where the conventional target of producing perfect, identical transistors that operate without upset can no longer be maintained while continuing to reduce the energy per operation. With power requirements already limiting chip performance, continuing to demand perfect, upset-free transistors would mean the end of scaling benefits. The big challenges in device variability and reliability are driven by uncommon tails in distributions, infrequent upsets, one-size-fits-all technology requirements, and a lack of information about the context of each operation. Solutions co-designed across traditional layer boundaries in our system stack can change the game, allowing architecture and software (a) to compensate for uncommon variation, environments, and events, (b) to pass down invariants and requirements for the computation, and (c) to monitor the health of collections of deVices. Cross-layer codesign provides a path to continue extracting benefits from further scaled technologies despite the fact that they may be less predictable and more variable. While some limited multi-layer mitigation strategies do exist, to move forward redefining traditional layer abstractions and developing a framework that facilitates cross-layer collaboration is necessary.

The Place of Operations upon the Sympathetic System in the Treatment of Poliomyelitis.

Science.gov (United States)

Ogilvie, W H

1933-02-01

Revived interest in sympathetic surgery originated in orthopaedics. Royle's theories and operations. Their trial, failure and final abandonment. Value of sympathetic operations widely investigated; while finality has not been reached they have proved effective for three main purposes: (1) Relief of pain especially in bladder diseases. (2) Removal of inhibition and sphincteric spasm in alimentary, anal and bladder diseases. (3) Production of vaso-dilatation in (a) vaso-spastic diseases; (b) vaso-degenerative diseases; (c) conditions not due to arterial disease in which increased blood supply is beneficial.Poliomyelitis falls into the last group.-Cause of poor blood supply uncertain; ? lack of function; ? upset of some reflex; ? paralysis of vaso-dilators.TWO PROBLEMS ARISE, BOTH OF WHICH MAY BE TREATED BY OPERATIONS ON THE SYMPATHETIC: (1) The cold, blue limb, which develops chilblains, sores, or even deep ulcers every winter, often stopping treatment and requiring patient to be confined to bed. (2) The limb with considerable and rapidly increasing shortening. Sometimes these limbs show a fair return of power, and were it not for the heavy boot made necessary by the shortening, the patient could be made to walk well.Method of attack.-(1) Periarterial sympathectomy; (2) ramisectomy; (3) ganglionectomy. Physiological basis of each. Criticism of (1) and (2).Details of the operation for ganglionectomy.-Alternative approaches and their advantages. The immediate and late results of the procedure.Five cases discussed briefly.

Methods and data for HTGR fuel performance and radionuclide release modeling during normal operation and accidents for safety analysis

International Nuclear Information System (INIS)

Verfondern, K.; Martin, R.C.; Moormann, R.

1993-01-01

The previous status report released in 1987 on reference data and calculation models for fission product transport in High-Temperature, Gas-Cooled Reactor (HTGR) safety analyses has been updated to reflect the current state of knowledge in the German HTGR program. The content of the status report has been expanded to include information from other national programs in HTGRs to provide comparative information on methods of analysis and the underlying database for fuel performance and fission product transport. The release and transport of fission products during normal operating conditions and during the accident scenarios of core heatup, water and air ingress, and depressurization are discussed. (orig.) [de

Using the PAW/PEM monitoring systems to support operations at Point Lepreau

International Nuclear Information System (INIS)

MacDonald, S.; McIntyre, M.; Dai, H.

1997-01-01

The plant data logger was brought on-line at the Point Lepreau Generating Station (PLGS) in 1992 in order to record information from instruments throughout the plant. Using the System Engineers Data Extraction (SEDE) utility, current plant data is at the fingertips of anyone with a network connection. System engineers can monitor the performance of their systems at any time and take pro-active measures to avoid problems with performance, as well as monitor behaviour during tests and plant upsets. Nuclear Safety personnel gather data for use in simulation and analysis validation, as well as to ensure that plant parameters are kept within the safe operating envelope. The PLGS operational safety group embarked on a project to develop a data management system. The project and the monitoring process has come to be known as the Plant Analysis Workbench (PAW). When the need for complex monitoring of safety system signals was identified, this led to a similar project called the Plant Expert Monitor (PEM). In this paper we present an overview of the functionality of both PAW and PEM, outlining in particular the expert system architecture in PEM and giving an example of its day-to-day use

A comparison study of the two-bladed partial pitch turbine during normal operation and an extreme gust conditions

International Nuclear Information System (INIS)

Kim, T; Petersen, M M; Larsen, T J

2014-01-01

This paper shows the load comparisons between the numerical simulation and the full-scale load measurement data. First part of this paper includes the comparisons of statistic load in terms of maximum, mean, and minimum values for the selected normal operation cases. The blade root bending moments and tower top bending moments are compared. Second part of this paper introduces the dynamic response comparisons during an extreme wind gust condition where the wind speed changed approximately 10 m/s during three seconds. The rotor speed and blade root flapwise and edgewise bending moment are compared. The nonlinear aeroelastic simulation code HAWC2 is used for the simulations. A very fine agreement between the simulated and the full-scale measured loads is seen for the both comparisons

Predictions of structural integrity of steam generator tubes under normal operating, accident, and severe accident conditions

International Nuclear Information System (INIS)

Majumdar, S.

1996-09-01

Available models for predicting failure of flawed and unflawed steam generator tubes under normal operating, accident, and severe accident conditions are reviewed. Tests conducted in the past, though limited, tended to show that the earlier flow-stress model for part-through-wall axial cracks overestimated the damaging influence of deep cracks. This observation is confirmed by further tests at high temperatures as well as by finite element analysis. A modified correlation for deep cracks can correct this shortcoming of the model. Recent tests have shown that lateral restraint can significantly increase the failure pressure of tubes with unsymmetrical circumferential cracks. This observation is confirmed by finite element analysis. The rate-independent flow stress models that are successful at low temperatures cannot predict the rate sensitive failure behavior of steam generator tubes at high temperatures. Therefore, a creep rupture model for predicting failure is developed and validated by tests under varying temperature and pressure loading expected during severe accidents

Is there a correlation between operative results and change in ventricular volume after shunt placement? A study of 60 cases of idiopathic normal-pressure hydrocephalus

Energy Technology Data Exchange (ETDEWEB)

Meier, U.; Graewe, A.; Hajdukova, A. [Department of Neurosurgery, Unfallkrankenhaus Berlin, Warener Strasse 7, 12683, Berlin (Germany); Paris, S.; Stockheim, D.; Mutze, S. [Department of Radiology, Unfallkrankenhaus Berlin, Warener Strasse 7, 12683, Berlin (Germany)

2003-06-01

In patients with communicating or normal-pressure hydrocephalus, ventricular volume decreases following implantation of differential pressure valves. We implanted hydrostatic (Miethke dual-switch) valves in 60 patients with normal-pressure hydrocephalus (NPH) between September 1997 and December 2001. The patients underwent CT 1 year after operation, and we measured the Evans index. Although 83% of the patients showed no change in ventricular volume as assessed by this index, 72% nevertheless showed good to excellent and 16% satisfactory clinical improvement, while 12% showed no improvement. Moderate or marked reduction in ventricular size was observed in 17%, of whom 40% of these patients showed good to excellent and 20% satisfactory clinical improvement; 40% showed unsatisfactory improvement. The favourable outcome following implantation of a hydrostatic shunt thus did not correlate with decreased ventricular volume 1 year after operation, better outcomes being observed in patients with little or no alteration in ventricular size than in those with a marked decrease. Postoperative change in ventricular volume in NPH thus does not have the same significance as in patients with high-pressure hydrocephalus. (orig.)

Is there a correlation between operative results and change in ventricular volume after shunt placement? A study of 60 cases of idiopathic normal-pressure hydrocephalus

International Nuclear Information System (INIS)

Meier, U.; Graewe, A.; Hajdukova, A.; Paris, S.; Stockheim, D.; Mutze, S.

2003-01-01

In patients with communicating or normal-pressure hydrocephalus, ventricular volume decreases following implantation of differential pressure valves. We implanted hydrostatic (Miethke dual-switch) valves in 60 patients with normal-pressure hydrocephalus (NPH) between September 1997 and December 2001. The patients underwent CT 1 year after operation, and we measured the Evans index. Although 83% of the patients showed no change in ventricular volume as assessed by this index, 72% nevertheless showed good to excellent and 16% satisfactory clinical improvement, while 12% showed no improvement. Moderate or marked reduction in ventricular size was observed in 17%, of whom 40% of these patients showed good to excellent and 20% satisfactory clinical improvement; 40% showed unsatisfactory improvement. The favourable outcome following implantation of a hydrostatic shunt thus did not correlate with decreased ventricular volume 1 year after operation, better outcomes being observed in patients with little or no alteration in ventricular size than in those with a marked decrease. Postoperative change in ventricular volume in NPH thus does not have the same significance as in patients with high-pressure hydrocephalus. (orig.)

Evaluation of flaws in carbon steel piping. Final report

Energy Technology Data Exchange (ETDEWEB)

Zahoor, A.; Gamble, R.M.; Mehta, H.S.; Yukawa, S.; Ranganath, S.

1986-10-01

The objective of this program was to develop flaw evaluation procedures and allowable flaw sizes for ferritic piping used in light water reactor (LWR) power generation facilities. The program results provide relevant ASME Code groups with the information necessary to define flaw evaluation procedures, allowable flaw sizes, and their associated bases for Section XI of the code. Because there are several possible flaw-related failure modes for ferritic piping over the LWR operating temperature range, three analysis methods were employed to develop the evaluation procedures. These include limit load analysis for plastic collapse, elastic plastic fracture mechanics (EPFM) analysis for ductile tearing, and linear elastic fracture mechanics (LEFM) analysis for non ductile crack extension. To ensure the appropriate analysis method is used in an evaluation, a step by step procedure also is provided to identify the relevant acceptance standard or procedure on a case by case basis. The tensile strength and toughness properties required to complete the flaw evaluation for any of the three analysis methods are included in the evaluation procedure. The flaw evaluation standards are provided in tabular form for the plastic collapse and ductile tearing modes, where the allowable part through flaw depth is defined as a function of load and flaw length. For non ductile crack extension, linear elastic fracture mechanics analysis methods, similar to those in Appendix A of Section XI, are defined. Evaluation flaw sizes and procedures are developed for both longitudinal and circumferential flaw orientations and normal/upset and emergency/faulted operating conditions. The tables are based on margins on load of 2.77 and 1.39 for circumferential flaws and 3.0 and 1.5 for longitudinal flaws for normal/upset and emergency/faulted conditions, respectively.

Evaluation of flaws in carbon steel piping. Final report

International Nuclear Information System (INIS)

Zahoor, A.; Gamble, R.M.; Mehta, H.S.; Yukawa, S.; Ranganath, S.

1986-10-01

The objective of this program was to develop flaw evaluation procedures and allowable flaw sizes for ferritic piping used in light water reactor (LWR) power generation facilities. The program results provide relevant ASME Code groups with the information necessary to define flaw evaluation procedures, allowable flaw sizes, and their associated bases for Section XI of the code. Because there are several possible flaw-related failure modes for ferritic piping over the LWR operating temperature range, three analysis methods were employed to develop the evaluation procedures. These include limit load analysis for plastic collapse, elastic plastic fracture mechanics (EPFM) analysis for ductile tearing, and linear elastic fracture mechanics (LEFM) analysis for non ductile crack extension. To ensure the appropriate analysis method is used in an evaluation, a step by step procedure also is provided to identify the relevant acceptance standard or procedure on a case by case basis. The tensile strength and toughness properties required to complete the flaw evaluation for any of the three analysis methods are included in the evaluation procedure. The flaw evaluation standards are provided in tabular form for the plastic collapse and ductile tearing modes, where the allowable part through flaw depth is defined as a function of load and flaw length. For non ductile crack extension, linear elastic fracture mechanics analysis methods, similar to those in Appendix A of Section XI, are defined. Evaluation flaw sizes and procedures are developed for both longitudinal and circumferential flaw orientations and normal/upset and emergency/faulted operating conditions. The tables are based on margins on load of 2.77 and 1.39 for circumferential flaws and 3.0 and 1.5 for longitudinal flaws for normal/upset and emergency/faulted conditions, respectively

Extending the application range of a fuel performance code from normal operating to design basis accident conditions

International Nuclear Information System (INIS)

Van Uffelen, P.; Gyori, C.; Schubert, A.; Laar, J. van de; Hozer, Z.; Spykman, G.

2008-01-01

Two types of fuel performance codes are generally being applied, corresponding to the normal operating conditions and the design basis accident conditions, respectively. In order to simplify the code management and the interface between the codes, and to take advantage of the hardware progress it is favourable to generate a code that can cope with both conditions. In the first part of the present paper, we discuss the needs for creating such a code. The second part of the paper describes an example of model developments carried out by various members of the TRANSURANUS user group for coping with a loss of coolant accident (LOCA). In the third part, the validation of the extended fuel performance code is presented for LOCA conditions, whereas the last section summarises the present status and indicates needs for further developments to enable the code to deal with reactivity initiated accident (RIA) events

Effect analysis of core barrel openings under CEFR normal condition

International Nuclear Information System (INIS)

Zhang Yabo; Yang Hongyi

2008-01-01

Openings on the bottom of core barrel are important part of the decay heat removal system of China Experimental Fast Reactor (CEFR), which are designed to discharge the decay heat from reactor under accident condition. This paper analyses the effect of the openings design on the normal operation condition using the famouse CFD code CFX. The result indicates that the decay heat can be discharged safely and at the same time the effect of core barrel openings on the normal operation condition is acceptable. (authors)

Lifetime analysis of the ITER first wall under steady-state and off-normal loads

International Nuclear Information System (INIS)

Mitteau, R; Sugihara, M; Raffray, R; Carpentier-Chouchana, S; Merola, M; Pitts, R A; Labidi, H; Stangeby, P

2011-01-01

The lifetime of the beryllium armor of the ITER first wall is evaluated for normal and off-normal operation. For the individual events considered, the lifetime spans between 930 and 35×10 6 discharges. The discrepancy between low and high estimates is caused by uncertainties about the behavior of the melt layer during off-normal events, variable plasma operation parameters and variability of the sputtering yields. These large uncertainties in beryllium armor loss estimates are a good example of the experimental nature of the ITER project and will not be truly resolved until ITER begins burning plasma operation.

Comparison of pre-operative dGEMRIC imaging with intra-operative findings in femoroacetabular impingement: preliminary findings

International Nuclear Information System (INIS)

Bittersohl, Bernd; Apprich, Sebastian; Siebenrock, Klaus A.; Mamisch, Tallal Charles; Hosalkar, Harish S.; Werlen, Stefan A.

2011-01-01

To study standard MRI and dGEMRIC in patients with symptomatic FAI undergoing surgical intervention and compare them with intra-operative findings to see if they were corroborative. Sixteen patients with symptomatic FAI that warranted surgical intervention were prospectively studied. All patients underwent plain radiographic series for FAI assessment followed by standard MRI and dGEMRIC. Subsequently, patients were surgically treated with safe dislocation and the joint was evaluated for any macroscopic signs of damaged cartilage. Data were statistically analyzed. A total of 224 zones in 16 patients were evaluated. One hundred and sixteen zones were intra-operatively rated as normal with mean T1 values of 510.1 ms ± 141.2 ms. Eighty zones had evidence of damage with mean T1 values of 453.1 ms ± 113.6 ms. The difference in these T1 values was significant (p = 0.003). Correlation between standard MRI and intra-operative findings was moderate (r = 0.535, p < 0.001). Intra-operative findings revealed more damage than standard MRI. On standard MRI, 68.6% zones were graded normal while 31.4% had evidence of damage. On intra-operative visualization, 56.4% zones were graded normal and 43.6% had evidence of damage. Correlation between dGEMRIC and intra-operative findings turned out to be weak (r = 0.114, p < 0.126). On T1 assessment 31.4% of zones were graded as normal and 68.6% as damaged. dGEMRIC was significantly different between normal and affected cartilage based on intra-operative assessment. The correlation for morphological findings was limited, underestimating defects. By combining morphological with biochemical assessment dGEMRIC may play some role in the future to prognosticate outcomes and facilitate surgical planning and intervention. (orig.)

Proceedings of the technical committee meeting on sodium removal and disposal from LMFRs in normal operation and in the framework of decommissioning

International Nuclear Information System (INIS)

Latge, C.

1997-11-01

This publication summarizes discussions and presented papers from the Technical Committee meeting on sodium removal and disposal from liquid metal fast reactors in normal operation and in the framework of decommissioning, organised by IAEA. The objective of this meeting was to provide a forum to review and exchange information on the international developments in technologies of sodium removal and disposal from liquid metal fast reactor components and systems in operation and maintenance conditions, and in framework of decommissioning. The technical parts of the meeting covered the three major subjects: sodium removal (cleaning) process, decontamination process and bulk disposal of sodium in the framework of decommissioning. These technologies were reviewed with regard to their implementation into current plants to improve operation and maintenance, and to develop an effective decommissioning program. Further, design for future Liquid metal fast reactors were reviewed in the context how they can accommodate today's technologies. The meeting resulted in an effective information exchange with the Member States sharing their needs as well as experiences in the mentioned topics

Proceedings of the technical committee meeting on sodium removal and disposal from LMFRs in normal operation and in the framework of decommissioning

Energy Technology Data Exchange (ETDEWEB)

Latge, C [ed.; CEA, Direction des Reacteurs Nucleaires, Departement d' Etudes des Reacteurs, CEA-Cadarache, Saint-Paul-lez-Durance (France)

1997-11-01

This publication summarizes discussions and presented papers from the Technical Committee meeting on sodium removal and disposal from liquid metal fast reactorsin normal operation and in the framework of decommissioning, organised by IAEA. The objective of this meeting was to provide a forum to review and exchange information on the international developments in technologies of sodium removal and disposal from liquid metal fast reactor components and systems in operation and maintenance conditions, and in framework of decommissioning. The technical parts of the meeting covered the three major subjects: sodium removal (cleaning) process, decontamination process and bulk disposal of sodium in the framework of decommissioning. These technologies were reviewed with regard to their implementation into current plants to improve operation and maintenance, and to develop an effective decommissioning program. Further, design for future Liquid metal fast reactors were reviewed in the context how they can accommodate today's technologies. The meeting resulted in an effective information exchange with the Member States sharing their needs as well as experiences in the mentioned topics.

New application of procedures computer to normal operating procedures

Energy Technology Data Exchange (ETDEWEB)

Medrano Carbajo, J.; Mendez Salguero, J.

2012-07-01

Currently, existing technologies in the operating power plants accused increasingly more problems of obsolescence and replacement of equipment supply. For this reason are spreading, to a greater or lesser extent, the projects of migration from analogue to digital technology systems. These systems, in line with the current situation of the industry, provide solutions to such problems and other advantages.

Emergency operation determination system

International Nuclear Information System (INIS)

Miki, Tetsushi.

1993-01-01

The system of the present invention can determine an emergency operation coping with abnormal events occurring during nuclear plant operation without replying on an operator's judgement. That is, the system of the present invention comprises an intelligence base which divides and classifies the aims of the plant operation for the function, structure and operation manual and puts them into network. Degree of attainment for the extend of the status normality is determined on every aim of operation based on various kinds of measured data during plant operation. For a degree of attainment within a predetermined range, it is judged that an emergency operation is possible although this is in an abnormal state. Degree of emergency is determined by a fuzzy theory based on the degree of attainment, variation coefficient for the degree of attainment and the sensitivity to external disturbance as parameters. Priority for the degree of emergency on every operation aims is determined by comparison. Normality is successively checked for the determined operation aims. As a result, equipments as objects of abnormality suppressing operation are specified, and the operation amount of the equipments as objects are determined so that the measuring data are within a predetermined range. (I.S.)

Construction of an external electrode for determination of electrochemical corrosion potential in normal operational conditions of an BWR type reactor for hot cells

International Nuclear Information System (INIS)

Aguilar T, J.A.; Rivera M, H.; Hernandez C, R.

2001-01-01

The behavior of the corrosion processes at high temperature requires of external devices that being capable to resist a temperature of 288 Centigrade and a pressure of 80 Kg/cm 2 , to give stable and reproducible results of some variable and resisting physically and chemically the radiation. The external electrode of Ag/AgCl fulfils all the requirements in the determination of the electrochemical corrosion potential under normal operational conditions of a BWR type reactor in hot cells. (Author)

Exogenous HIV-1 Nef upsets the IFN-γ-induced impairment of human intestinal epithelial integrity.

Directory of Open Access Journals (Sweden)

Maria Giovanna Quaranta

Full Text Available The mucosal tissues play a central role in the transmission of HIV-1 infection as well as in the pathogenesis of AIDS. Despite several clinical studies reported intestinal dysfunction during HIV infection, the mechanisms underlying HIV-induced impairments of mucosal epithelial barrier are still unclear. It has been postulated that HIV-1 alters enterocytic function and HIV-1 proteins have been detected in several cell types of the intestinal mucosa. In the present study, we analyzed the effect of the accessory HIV-1 Nef protein on human epithelial cell line.We used unstimulated or IFN-γ-stimulated Caco-2 cells, as a model for homeostatic and inflamed gastrointestinal tracts, respectively. We investigated the effect of exogenous recombinant Nef on monolayer integrity analyzing its uptake, transepithelial electrical resistance, permeability to FITC-dextran and the expression of tight junction proteins. Moreover, we measured the induction of proinflammatory mediators. Exogenous Nef was taken up by Caco-2 cells, increased intestinal epithelial permeability and upset the IFN-γ-induced reduction of transepithelial resistance, interfering with tight junction protein expression. Moreover, Nef inhibited IFN-γ-induced apoptosis and up-regulated TNF-α, IL-6 and MIP-3α production by Caco-2 cells while down-regulated IL-10 production. The simultaneous exposure of Caco-2 cells to Nef and IFN-γ did not affect cytokine secretion respect to untreated cells. Finally, we found that Nef counteracted the IFN-γ induced arachidonic acid cascade.Our findings suggest that exogenous Nef, perturbing the IFN-γ-induced impairment of intestinal epithelial cells, could prolong cell survival, thus allowing for accumulation of viral particles. Our results may improve the understanding of AIDS pathogenesis, supporting the discovery of new therapeutic interventions.

Evaluation of gap heat transfer model in ELESTRES for CANDU fuel element under normal operating conditions

International Nuclear Information System (INIS)

Lee, Kang Moon; Ohn, Myung Ryong; Im, Hong Sik; Choi, Jong Hoh; Hwang, Soon Taek

1995-01-01

The gap conductance between the fuel and the sheath depends strongly on the gap width and has a significant influence on the amount of initial stored energy. The modified Ross and Stoute gap conductance model in ELESTRES is based on a simplified thermal deformation model for steady-state fuel temperature calculations. A review on a series of experiments reveals that fuel pellets crack, relocate, and are eccentrically positioned within the sheath rather than solid concentric cylinders. In this paper, the two recently-proposed gap conductance models (offset gap model and relocated gap model) are described and are applied to calculate the fuel-sheath gap conductances under experimental conditions and normal operating conditions in CANDU reactors. The good agreement between the experimentally-inferred and calculated gap conductance values demonstrates that the modified Ross and Stoute model was implemented correctly in ELESTRES. The predictions of the modified Ross and Stoute model provide conservative values for gap heat transfer and fuel surface temperature compared to the offset gap and relocated gap models for a limiting power envelope. 13 figs., 3 tabs., 16 refs. (Author)

Ultrasonographic features of normalization of the pylorus after pyloromyotomy for hypertrophic pyloric stenosis.

Science.gov (United States)

Yoshizawa, J; Eto, T; Higashimoto, Y; Saitou, T; Maie, M

2001-04-01

The purpose of this study was to describe the time course, early postoperative changes, and morphologic features of normalization of the pylorus after pyloromyotomy for hypertrophic pyloric stenosis. The subjects were 17 infants (9 boys, 8 girls) who underwent umbilical incision Ramstedt pyloromyotomy. The pyloric muscle mass was measured immediately before the operation and then at intervals from 3 days to 6 months after the operation using a 7.5-MHz ultrasound probe. In longitudinal section, the dorsal part of the pyloric muscle thickened transiently and then thinned to normal values by 5 months after the operation. It was 5.1 +/- 0.8 mm (mean +/- SD) preoperatively, increased to 6.0 +/- 0.3 mm by day 3 after the operation (P thick preoperatively, thickened to 4.6 +/- 0.4 mm by 3 days after the operation (P thickness within the first few postoperative days followed by a slow decrease that reaches normal thickness (thickness is accompanied by a gradual decrease in length to 75% of the preoperative value by 5 months. The morphologic features in this normalization are first a wedge (day 3), then a flat tire (days 7 and 14), and finally an elongated ring (5 months). J Pediatr Surg 36:582-586. Copyright 2001 by W.B. Saunders Company.

Conceptual analysis of a preliminary model for instability study in normal operation of a natural circulation reactor type EBWR, using Relap5/Mod 3.2

International Nuclear Information System (INIS)

Ojeda S, J.; Morales S, J.; Chavez M, C.

2009-10-01

This work intends a model using the code Relap5/Mod 3.2, for the instability study in normal operation of a natural circulation reactor type ESBWR. A conceptual analysis is considered because all the information was obtained of the open literature, and some of reactor operation or dimension (not available) parameters were approached. As starting point was took the pattern developed for reactor type BWR, denominated Browns Ferry and changes were focused in elimination of bonds of forced recirculation, in modification of operation parameters, dimensions and own control parameters, according to internal code structure. Additionally the nodalization outline is described analyzing for separate the four fundamental areas employees in peculiar geometry of natural circulation reactor. Comparative analysis of results of stability behavior obtained with those reported in the open literature were made, by part of commercial reactor designer ESBWR. (Author)

Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans.

Science.gov (United States)

Makihara, Yukiko; Segal, Richard L; Wolpaw, Jonathan R; Thompson, Aiko K

2014-09-15

In normal animals, operant conditioning of the spinal stretch reflex or the H-reflex has lesser effects on synergist muscle reflexes. In rats and people with incomplete spinal cord injury (SCI), soleus H-reflex operant conditioning can improve locomotion. We studied in normal humans the impact of soleus H-reflex down-conditioning on medial (MG) and lateral gastrocnemius (LG) H-reflexes and on locomotion. Subjects completed 6 baseline and 30 conditioning sessions. During conditioning trials, the subject was encouraged to decrease soleus H-reflex size with the aid of visual feedback. Every sixth session, MG and LG H-reflexes were measured. Locomotion was assessed before and after conditioning. In successfully conditioned subjects, the soleus H-reflex decreased 27.2%. This was the sum of within-session (task dependent) adaptation (13.2%) and across-session (long term) change (14%). The MG H-reflex decreased 14.5%, due mainly to task-dependent adaptation (13.4%). The LG H-reflex showed no task-dependent adaptation or long-term change. No consistent changes were detected across subjects in locomotor H-reflexes, EMG activity, joint angles, or step symmetry. Thus, in normal humans, soleus H-reflex down-conditioning does not induce long-term changes in MG/LG H-reflexes and does not change locomotion. In these subjects, task-dependent adaptation of the soleus H-reflex is greater than it is in people with SCI, whereas long-term change is less. This difference from results in people with SCI is consistent with the fact that long-term change is beneficial in people with SCI, since it improves locomotion. In contrast, in normal subjects, long-term change is not beneficial and may necessitate compensatory plasticity to preserve satisfactory locomotion. Copyright © 2014 the American Physiological Society.

Embedded 3D Nonvolatile Memory, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Integrated circuits in NASA spacecraft and vehicle electronics must operate over large temperature extremes and mitigate radiation effects that can result in upset...

Redefining the Indirect Approach, Defining Special Operations Forces (SOF Power, and the Global Networking of SOF

Directory of Open Access Journals (Sweden)

Scott Morrison

2014-07-01

Full Text Available The current Defense Strategy assigns Special Operations Forces (SOF to play a central role in countering terrorism, weapons of mass destruction, and irregular warfare. However, there has been little published that defines the role of Special Operations alongside air, land, and sea domains. The U.S. Special Operations Community struggles to define its own theoretical concepts such as direct approach and indirect approach. The U.S. SOF circles typically define direct approach with direct action and the indirect approach with foreign internal defense or security force assistance. Military theorist Liddell Hart viewed the indirect approach as a method to orient upon, target, and upset an adversary’s equilibrium in order to plan for and direct decisive blows. Today, the SOF indirect approach is arguable more applicable due to the prevalence of non-state threats and internal conflicts. Following Hart’s definition, precision raids are among the integral components of a broader application of the indirect approach. The approach also networks U.S. government power as a force when used in concert with allies and local partners. Global networking along with balanced precision raids will exponentially increase the utility of SOF power and position it to appropriately complement all domains to tackle 21st century challenges.

Safety analysis of the post-operational phase

International Nuclear Information System (INIS)

Berg, H.P.; Ehrlich, D.

1991-01-01

The safety analysis of normal operation covers an analytical study of the system parts ultimate repository - waste forms of the ultimate repository system under normal and accidental operation. On that basis a requirement concept has been developed which entails reactions on planning and design of the repository, and requirements of waste products, packagings and permissible activities. The procedure for the operational phase is explained giving the Konrad repository project as an example. (DG) [de

Vertex Normals and Face Curvatures of Triangle Meshes

KAUST Repository

Sun, Xiang

2016-08-12

This study contributes to the discrete differential geometry of triangle meshes, in combination with discrete line congruences associated with such meshes. In particular we discuss when a congruence defined by linear interpolation of vertex normals deserves to be called a ʼnormal’ congruence. Our main results are a discussion of various definitions of normality, a detailed study of the geometry of such congruences, and a concept of curvatures and shape operators associated with the faces of a triangle mesh. These curvatures are compatible with both normal congruences and the Steiner formula.

FREC-4A: a computer program to predict fuel rod performance under normal reactor operation

International Nuclear Information System (INIS)

Harayama, Yasuo; Izumi, Fumio

1981-10-01

The program FREC-4A (Fuel Reliability Evaluation Code-version 4A) is used for predicting fuel rod performance in normal reactor operation. The performance is calculated in accordance with the irradiation history of fuel rods. Emphasis is placed on the prediction of the axial elongation of claddings induced by pellet-cladding mechanical interaction, including the influence of initially preloaded springs inserted in fuel rod lower plenums. In the FREC-4A, an fuel rod is divided into axial segments. In each segment, it is assumed that the temperature, stress and strain are axi-symmetrical, and the axial strain in constant in fuel pellets and in a cladding, though the values in the pellets and in the cladding are different. The calculation of the contact load and the clearance along the length of a fuel rod and the stress and strain in each segment is explained. The method adopted in the FREC-4A is simple, and suitable to predict the deformation of fuel rods over their full length. This report is described on the outline of the program, the method of solving the stiffness equations, the calculation models, the input data such as irradiation history, output distribution, material properties and pores, the printing-out of input data and calculated results. (Kako, I.)

ORTAP: a nuclear steam supply system simulation for the dynamic analysis of high temperature gas cooled reactor transients

International Nuclear Information System (INIS)

Cleveland, J.C.; Hedrick, R.A.; Ball, S.J.; Delene, J.G.

1977-01-01

ORTAP was developed to predict the dynamic behavior of the high temperature gas cooled reactor (HTGR) Nuclear Steam Supply System for normal operational transients and postulated accident conditions. It was developed for the Nuclear Regulatory Commission (NRC) as an independent means of obtaining conservative predictions of the transient response of HTGRs over a wide range of conditions. The approach has been to build sufficient detail into the component models so that the coupling between the primary and secondary systems can be accurately represented and so that transients which cover a wide range of conditions can be simulated. System components which are modeled in ORTAP include the reactor core, a typical reheater and steam generator module, a typical helium circulator and circulator turbine and the turbine generator plant. The major plant control systems are also modeled. Normal operational transients which can be analyzed with ORTAP include reactor start-up and shutdown, normal and rapid load changes. Upset transients which can be analyzed with ORTAP include reactor trip, turbine trip and sudden reduction in feedwater flow. ORTAP has also been used to predict plant response to emergency or faulted conditions such as primary system depressurization, loss of primary coolant flow and uncontrolled removal of control poison from the reactor core

Peripartum haemodynamic status of bitches with normal birth or dystocia.

Science.gov (United States)

Lúcio, C F; Silva, L C G; Rodrigues, J A; Veiga, G A L; Vannucchi, C I

2009-07-01

There has been limited investigation of parturition in the bitch and there is little information published on clinical and obstetrical examination other than opinion and anecdote. While there are substantial data on haemodynamic and vascular changes during normal parturition in humans, little is known about the physiological events in the dog. This study was aimed at maternal haemodynamic changes occurring during normal parturition and to investigate how these were modified in bitches with dystocia (DYST) treated either medically or via assisted delivery and caesarean operation. Three groups of 10 bitches were investigated; those with normal parturition, those with DYST corrected by manipulative assistance or caesarean operation and those with uterine inertia treated by oxytocin administration. Heart rate, systolic and diastolic blood pressure, electrocardiogram and blood glucose concentration were measured pre-partum, intra-partum, immediately after parturition and 1 h later. Heart rate was high at all times throughout the study and the majority of bitches had normal sinus rhythm. Blood pressure was generally within the normal range, and although systolic and diastolic blood pressure was highest during the intra-partum period and sometimes during the immediate post-partum period, there were no significant differences between groups. All bitches had blood glucose concentrations within the normal range throughout the study although pre-partum concentrations were statistically lower than many of the other time periods. The study provides useful physiological data that will facilitate monitoring and clinical management of bitches throughout normal parturition and DYST.

Experimental program on fuel rod behaviour under off-normal conditions

International Nuclear Information System (INIS)

Languille, A.; Cecchi, P.

1985-01-01

During LMFBR plant operation, fuel developments are primarily concerned with the fuel pin irradiation behaviour under steady-state conditions up to high burn-up levels. But additional studies under off-normal conditions are necessary in order to assess fuel pin performance and to define operational limits. (author)

Formulation of a strategy for monitoring control integrity in critical digital control systems

Science.gov (United States)

Belcastro, Celeste M.; Fischl, Robert; Kam, Moshe

1991-01-01

Advanced aircraft will require flight critical computer systems for stability augmentation as well as guidance and control that must perform reliably in adverse, as well as nominal, operating environments. Digital system upset is a functional error mode that can occur in electromagnetically harsh environments, involves no component damage, can occur simultaneously in all channels of a redundant control computer, and is software dependent. A strategy is presented for dynamic upset detection to be used in the evaluation of critical digital controllers during the design and/or validation phases of development. Critical controllers must be able to be used in adverse environments that result from disturbances caused by an electromagnetic source such as lightning, high intensity radiated field (HIRF), and nuclear electromagnetic pulses (NEMP). The upset detection strategy presented provides dynamic monitoring of a given control computer for degraded functional integrity that can result from redundancy management errors and control command calculation error that could occur in an electromagnetically harsh operating environment. The use is discussed of Kalman filtering, data fusion, and decision theory in monitoring a given digital controller for control calculation errors, redundancy management errors, and control effectiveness.

Single-Event Effect Performance of a Conductive-Bridge Memory EEPROM

Science.gov (United States)

Chen, Dakai; Wilcox, Edward; Berg, Melanie; Kim, Hak; Phan, Anthony; Figueiredo, Marco; Seidleck, Christina; LaBel, Kenneth

2015-01-01

We investigated the heavy ion single-event effect (SEE) susceptibility of the industry’s first stand-alone memory based on conductive-bridge memory (CBRAM) technology. The device is available as an electrically erasable programmable read-only memory (EEPROM). We found that single-event functional interrupt (SEFI) is the dominant SEE type for each operational mode (standby, dynamic read, and dynamic write/read). SEFIs occurred even while the device is statically biased in standby mode. Worst case SEFIs resulted in errors that filled the entire memory space. Power cycle did not always clear the errors. Thus the corrupted cells had to be reprogrammed in some cases. The device is also vulnerable to bit upsets during dynamic write/read tests, although the frequency of the upsets are relatively low. The linear energy transfer threshold for cell upset is between 10 and 20 megaelectron volts per square centimeter per milligram, with an upper limit cross section of 1.6 times 10(sup -11) square centimeters per bit (95 percent confidence level) at 10 megaelectronvolts per square centimeter per milligram. In standby mode, the CBRAM array appears invulnerable to bit upsets.

Range of the radiation monitor for the rigid vent of primary containment during normal and emergency operation for a BWR-5 in Laguna Verde

International Nuclear Information System (INIS)

Tijerina S, F.; Pozos S, A. M.; Cabrera U, S.; Mata A, J. A.; Sandoval V, S.; Ovando C, R.; Vargas A, A.; Gallardo R, I.; Cruz G, M.; Amador C, C.

2014-10-01

The earthquake followed by a tsunami, happened in March, 2011 in the coasts of oriental Japan, caused damages in the nuclear power plants 1 at 4 of Fukushima Daiichi leading to damage of the fuel in three of the reactors and to the radiation liberation to the exterior. As consequence of those events, the regulations requires that the power plants with Primary Containment type Mark I and II evaluate to have a system of rigid vent with a monitoring equipment of radiation effluents. The present work covers the rigid vent of diameter 12 of the Primary Containment, type Mark-II, of nuclear power plant of Laguna Verde in conditions of severe accident and normal operation, low regime of Extended Power Up rate (EPU - 2317 MWt), using the codes MAAP3B, MICROSHILED 5.05 and the Bardach Black Boxes methodology. As a result the measurement range of the radiation monitor that is required for monitoring the gassy liberation to the atmosphere was determined. The conclusion is that the superior limit of the range of the radiation meter during a Severe Accident is of 8.55 E + 05 R/h (8.55 E + 08 m R/h) and the superior limit in normal operation of 1.412 E-11 at 2.540 E-7 R/h (1.412 E-14 at 2.540 E-10 m R/h). (Author)

Evaluation of design variants for improved inherent regulation of advanced small modular reactors - 15325

International Nuclear Information System (INIS)

Vilim, R.B.; Passerini, S.

2015-01-01

This paper examines design variants that can improve inherent regulation in Advanced Small Modular Reactors (ASMR). It looks at the nature of unprotected upsets and then develops appropriate design measures to ensure that no upset can override a capability for safe self-regulation. This work adopts a reference sodium fast reactor (SFR) design to serve as a baseline for operational and safety performance and for comparison with variants on this design. The effect of design measures on plant stability is then examined. It is found that compared to full-power operation, the stability margin is reduced under islanded-operation. Islanded-operation is more likely for an ASMR deployed in a small regional electric grid with high penetration of renewable energy sources. The stability of core power production is a function of the inlet temperature coefficient, coolant transport times, and temperature-front attenuation in heat exchangers. The interaction of these phenomena with the control system is described

Process modeling study of the CIF incinerator

International Nuclear Information System (INIS)

Hang, T.

1995-01-01

The Savannah River Site (SRS) plans to begin operating the Consolidated Incineration Facility (CIF) in 1996. The CIF will treat liquid and solid low-level radioactive, mixed and RCRA hazardous wastes generated at SRS. In addition to experimental test programs, process modeling was applied to provide guidance in areas of safety, environmental regulation compliances, process improvement and optimization. A steady-state flowsheet model was used to calculate material/energy balances and to track key chemical constituents throughout the process units. Dynamic models were developed to predict the CIF transient characteristics in normal and abnormal operation scenarios. Predictions include the rotary kiln heat transfer, dynamic responses of the CIF to fluctuations in the solid waste feed or upsets in the system equipments, performance of the control system, air inleakage in the kiln, etc. This paper reviews the modeling study performed to assist in the deflagration risk assessment

Analysis of LOFT pressurizer spray and surge nozzles to include a 4500F step transient

International Nuclear Information System (INIS)

Nitzel, M.E.

1978-01-01

This report presents the analysis of the LOFT pressurizer spray and surge nozzles to include a 450 0 F step thermal transient. Previous analysis performed under subcontract by Basic Technology Incorporated was utilized where applicable. The SAASIII finite element computer program was used to determine stress distributions in the nozzles due to the step transient. Computer results were then incorporated in the necessary additional calculations to ascertain that stress limitations were not exceeded. The results of the analysis indicate that both the spray and surge nozzles will be within stress allowables prescribed by subsubarticle NB-3220 of the 1974 edition of the ASME Boiler and Pressure Vessel Code when subjected to currently known design, normal operating, upset, emergency, and faulted condition loads

Figurative and Operative Bases of Memory: Evidence from Normal and Learning Disabled Child.

Science.gov (United States)

Trepanier, Mary L.; Liben, Lynn S.

A set of studies investigated the relative importance of operative schemes and figurative (rote) memory. In Study I, 60 concrete operational children from grades 1-4 were asked to reconstruct two types of stimuli from memory. In order to separate the effects of operative and figurative skill use, learning disabled children with poor figurative…

Computer algebra and operators

Science.gov (United States)

Fateman, Richard; Grossman, Robert

1989-01-01

The symbolic computation of operator expansions is discussed. Some of the capabilities that prove useful when performing computer algebra computations involving operators are considered. These capabilities may be broadly divided into three areas: the algebraic manipulation of expressions from the algebra generated by operators; the algebraic manipulation of the actions of the operators upon other mathematical objects; and the development of appropriate normal forms and simplification algorithms for operators and their actions. Brief descriptions are given of the computer algebra computations that arise when working with various operators and their actions.

The efficacy of normal saline irrigation to prevent surgical site infection

International Nuclear Information System (INIS)

Ashraf, V.; Awan, A.S.

2015-01-01

The efficacy of normal saline irrigation to prevent surgical site Infection The aim of the study was to evaluate the efficacy of normal saline irrigations to prevent surgical site infection (SSI). Study Design: A comparative study. Place and Duration of Study: The study was conducted at surgery and gynecology Dept CMH Chunian from 1st Jan 2012 to 1st Nov 2012. Patients and Methods: Two hundred clean surgical and gynecological cases were included in the study. Hundred cases which were randomly selected had their wound washed with warm normal saline for 60 sec and then mopped dry with clean swabs. Subcuticular Stitches were applied to all the 200 cases. The surgical wounds were examined on 3rd post operative day and then finally on 15th post operative day. Patients with wound infection developed pain at the operation site and fever on third post operative day. Wounds were examined for swelling, redness, discharge and stitch abscess. Routine investigations were done as per protocol. Wound swabs were taken for culture and sensitivity. Results: The study was carried out on 200 clean cases (general and gynecological). They were 130 females and 70 males. The 100 cases whose wounds were washed with normal saline only 1 patient developed wound infection while in the other group who did not had saline irrigations 8 patients out of 100 developed wound infection. The commonest infective organisms were staphylococcus aureus and the other organisms were streptococcus pyogenes, proteus, Klaebsiella, E coli and pseudomonas. No MRSA was detected. Conclusion: In our study washing the wound with warm normal saline for 60 seconds resulted in the wound being infection free. Wound infection is associated with delayed wound healing, prolonged hospital stay and increased economic pressure on the patient and on the state. (author)

Role of check operators in achieving operational excellence at Virginia Power's nuclear stations

International Nuclear Information System (INIS)

Shriver, B.L.; Williams, T.M.; Stewart, W.L.

1987-01-01

Virginia Power has implemented a Check Operator Program as a part of its commitment to excellence in the operation of the North Anna and Surry nuclear power stations. The Check Operator Program utilizes highly qualified licensed personnel to independently evaluate the performance of licensed operators and senior operators during normal, abnormal and simulated emergency conditions. Emphasis is placed upon individual and team performance as well as the procedures and training which support the operators. The check operators report to line management to ensure that their recommendations are implemented into the overall operations philosophy of the power station

Normally-off GaN Transistors for Power Applications

International Nuclear Information System (INIS)

Hilt, O; Bahat-Treidel, E; Brunner, F; Knauer, A; Zhytnytska, R; Kotara, P; Wuerfl, J

2014-01-01

Normally-off high voltage GaN-HFETs for switching applications are presented. Normally-off operation with threshold voltages of 1 V and more and with 5 V gate swing has been obtained by using p-type GaN as gate. Different GaN-based buffer types using doping and backside potential barriers have been used to obtain blocking strengths up to 1000 V. The increase of the dynamic on-state resistance is analyzed for the different buffer types. The best trade-off between low dispersion and high blocking strength was obtained for a modified carbon-doped GaN-buffer that showed a 2.6x increase of the dynamic on-state resistance for 500 V switching as compared to switching from 20 V off-state drain bias. Device operation up to 200 °C ambient temperature without any threshold voltage shift is demonstrated.

Signal sensing of the internal ducts inspection robot: GIRINO (Get Inside Robot to Impel Normal Operation); Sensoriamento de sinais do robo de inspecao interna de dutos: GIRINO (Gabarito Interno Robotizado de Incidencia Normal ao Oleoduto)

Energy Technology Data Exchange (ETDEWEB)

Panta, Pedro G.; Dutra, Max S. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE); Santos, Auderi V.; Ferreira, Rodrigo C. [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Centro de Estudos em Telecomunicacoes; Reis, Ney S. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

2004-07-01

One of the major challenges in the operation field of subway oil pipelines is the presence of blockades caused by paraffin and hydrates accumulation. The maintenance and inspection inside pipelines practiced until now imply complicated risky processes for people and equipment involved in daily operational activities. The Get Inside Robot to Impel Normal Operation (G.I.R.I.N.O.) is a robot developed by the Robotic Laboratory of PETROBRAS Research Center, that aims at looking for less risky ways in internal inspection process of pipelines which displacement movements are generated by hydraulic energy. In order to get the inspection and displacement functions, the G.I.R.I.N.O. needs a constant internal movement monitoring that is made by its several parts; the interaction with the environment in diverse processes. This paper has the objective of proposing a monitoring system for the 14 inch duct G.I.R.I.N.O. For this end, a study of available components for receiving , signal processing and visualization used in the industry that fulfill the basic requirements of the robot's performance was done. The choice of the proposed devices considers these main features: size, power consumption and marinization capability. (author)

A viable on-chip FPGA configuration memory scrubbing approach for CBM-ToF

Energy Technology Data Exchange (ETDEWEB)

Oancea, Andrei-Dumitru; Stuellein, Christian; Manz, Sebastian; Gebelein, Jano; Kebschull, Udo [Infrastruktur und Rechnersysteme in der Informationsverarbeitung (IRI), Goethe-Universitaet, Senckenberganlage 31, 60325 Frankfurt am Main (Germany); Collaboration: CBM-Collaboration

2015-07-01

The ToF Detector of the CBM Experiment will be equipped with FPGA-based read-out boards (ROBs). These ROBs will be operated in a radiation environment, and therefore need a mitigation mechanism against soft errors in the SRAM-based configuration memories of the FPGAs. The proposed approach combines intrinsic on-chip single upset correction with extrinsic selective frame scrubbing for multiple-bit upsets. The slow control is realized using the GBT-SCA, which is capable of handling interrupts. This enables the new approach of event-driven configuration frame correction. While conventional blind scrubbing leads to a continuous load on the control path, the selective frame scrubbing reduces this load to a minimum. For verification purposes, radiation tests with a proton beam were performed at COSY, Juelich. The occurred soft errors were classified into single and multiple- bit upsets, enabling an estimation of the rate at which extrinsic intervention is necessary.

[Study on FTIR spectra of finger nails of normal people and patients of esophagus cancer].

Science.gov (United States)

Wang, Hong-Yan; Lü, Yin; Wang, Fan; Ma, Xiao-Dong; Jiang, Shi-Ping; Wang, Wei; Li, Cheng-Xiang

2008-02-01

To investigate the application of human finger nails in the diagnosis of cancer, Fourier transform infrared (FTIR) spectroscopy was employed to study the finger nails from some normal people and some with esophagus cancer and others with an operation for curing esophagus cancer five months ago. The results showed that there are obvious differences between FTIR spectra in them in spectral parameters such as frequency, intensity and band shape etc. The changes in the phosphate symmetric stretching vibration v(s) (PO2-) and asymmetric stretching vibration v(a)s(PO2-) modes are uniform, the v(s) (PO2-) and v(a)s(PO2-) absorption peaks of cancerous ones shift to high wave number compared with those of normal people, while those with operation shift to low wave number compared with those of cancerous ones. The C-O stretching vibration mode of protein located at 1 164 cm(-1) is composed of three absorption peaks located at 1 173.3, 1 158.0 and 1 151.1 cm(-1) respectively, meanwhile, the intensities and the wave numbers of the three peaks of cancerous ones all increase compared with normal people. The wave numbers of amide I and amide II of cancerous ones are both lower than those of normal people, while those with operation are between the cancerous ones and normal people, which suggest that the contents of protein and alpha-helix in finger nails of normal people, cancerous ones and the ones with operation are discriminative. The peak of bending vibration delta(CH2) mode of CH2 groups of protein lipid of cancerous ones shifts to high wave number slightly and the intensity of the peak weakens compared with that of normal people, which indicate that the methylene chain in the finger nails membrane lipids of cancerous ones is more ordered than that of normal people. Nevertheless, the peak of stretching vibration v(s) (CH2) of cancerous ones is lower than that of normal people, while that of the ones with operation is between cancerous ones and normal ones. As a result, the

Characterisation of radioactive waste at Cernavoda NPP Unit 1 during normal operation

International Nuclear Information System (INIS)

Iordache, M.; Bujoreanu, L.; Popescu, I. V.

2008-01-01

During the operation of a nuclear plant significant quantities of radioactive waste results that have a very large diversity. At Cernavoda NPP the important waste categories are non-radioactive wastes and radioactive wastes, which are manipulated completely different from which other. For a CANDU type reactor, the production of radioactive wastes is due to contamination with the following types of radioactive substances: - fission products resulting from nuclear fuel burning; - activated products of materials which form part of the technological systems; - activated products of process fluids. Radioactive wastes can be in solid, liquid or gas form. At Cernavoda NPP the solid wastes represent about 70% of the waste volume which is produced during plant operation and as a consequence of maintenance and decontamination activities. The most important types of solid wastes that are obtained and then handled, processed (if required) and temporarily stored are: solid low level radioactive wastes (classified as compact and non-compact), solid medium radioactive wastes, spent resins, used filters and filter cartridges. The liquid radioactive waste class includes organic liquids (used oil, scintillator liquids and used solvents) and aqueous wastes resulting from process system operating, decontamination and maintenance operations. Radioactive gas wastes occur subsequent to the fission process inside the fuel elements as well as due to the process fluids neutron activation in the reactor systems. As result of the plant operation, iodine, noble gases, tritium and radioactive particles occur and are passed to the ventilation stack in a controlled manner so that an exceeding of the maximum permissible concentrations of radioactive material to the environment should not occur. (authors)

A study on probabilistic fracture mechanics for nuclear pressure vessels and piping

International Nuclear Information System (INIS)

Yagawa, Genki; Yoshimura, Shinobu

1997-01-01

This paper describes some recent research activities on probabilistic fracture mechanics (PFM) for nuclear pressure vessels and piping (PV and P) performed by the RC111 research committee of the Japan Society of Mechanical Engineers (JSME) under a subcontract of the Japan Atomic Energy Research Institute (JAERI). To establish standard procedures for evaluating failure probabilities of nuclear PV and P, we have set up the following three kinds of PFM round-robin problems on: (a) primary piping under normal operating conditions, (b) aged reactor pressure vessel (RPV) under normal and upset operating conditions, and (c) aged RPV under pressurised thermal shock (PTS) events. The basic problems of the last one are chosen from some US benchmark problems such as EPRI (Electric Power Research Institute) and US NRC (Nuclear Regulatory Commission) joint PTS benchmark problems. This paper summarizes some sensitivity studies on the three kinds of problems mainly varying material properties such as flow stress, fracture toughness, fatigue crack growth rate, Cu content. Employed in this study are the PFM computer codes developed in Japan and USA. Failure probabilities of nuclear PV and P are quantitatively discussed in detail. (author)

Development and Implementation of Mechanistic Terry Turbine Models in RELAP-7 to Simulate RCIC Normal Operation Conditions

Energy Technology Data Exchange (ETDEWEB)

Zhao, Haihua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zou, Ling [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Hongbin [Idaho National Lab. (INL), Idaho Falls, ID (United States); O' Brien, James Edward [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-09-01

As part of the efforts to understand the unexpected “self-regulating” mode of the RCIC (Reactor Core Isolation Cooling) systems in Fukushima accidents and extend BWR RCIC and PWR AFW (Auxiliary Feed Water) operational range and flexibility, mechanistic models for the Terry turbine, based on Sandia’s original work [1], have been developed and implemented in the RELAP-7 code to simulate the RCIC system. In 2016, our effort has been focused on normal working conditions of the RCIC system. More complex off-design conditions will be pursued in later years when more data are available. In the Sandia model, the turbine stator inlet velocity is provided according to a reduced-order model which was obtained from a large number of CFD (computational fluid dynamics) simulations. In this work, we propose an alternative method, using an under-expanded jet model to obtain the velocity and thermodynamic conditions for the turbine stator inlet. The models include both an adiabatic expansion process inside the nozzle and a free expansion process outside of the nozzle to ambient pressure. The combined models are able to predict the steam mass flow rate and supersonic velocity to the Terry turbine bucket entrance, which are the necessary input information for the Terry turbine rotor model. The analytical models for the nozzle were validated with experimental data and benchmarked with CFD simulations. The analytical models generally agree well with the experimental data and CFD simulations. The analytical models are suitable for implementation into a reactor system analysis code or severe accident code as part of mechanistic and dynamical models to understand the RCIC behaviors. The newly developed nozzle models and modified turbine rotor model according to the Sandia’s original work have been implemented into RELAP-7, along with the original Sandia Terry turbine model. A new pump model has also been developed and implemented to couple with the Terry turbine model. An input

President's Commission and the normal accident

International Nuclear Information System (INIS)

Perrow, C.

1982-01-01

This chapter incorporates the major points of an analysis of the accident at Three Mile Island that I prepared in September 1979. In contrast to the findings of the President's Commission (1979), I did not view the accident as the result of operator error, an inept utility, or a negligent Nuclear Regulatory Commission but as a consequence of the complexity and interdependence that characterize the system itself. I argued that the accident was inevitable-that is, that it could not have been prevented, foreseen, or quickly terminated, because it was incomprehensible. It resembled other accidents in nuclear plants and in other high risk, complex and highly interdependent operator-machine systems; none of the accidents were caused by management or operator ineptness or by poor government regulation, though these characteristics existed and should have been expected. I maintained that the accident was normal, because in complex systems there are bound to be multiple faults that cannot be avoided by planning and that operators cannot immediately comprehend

Variation of radioactivity in the environmental media and dose evaluation in Suzhou city after normal operation of Qinshan Nuclear Power Station condition

International Nuclear Information System (INIS)

Fu Rongchu; Liu Li

2002-01-01

Objective: To study the radioactive monitoring in environmental media of Suzhou City when Qinshan Nuclear Power Station was in normal operational condition (from 1992-2001). Methods: The radiochemical method was used for monitoring the radioactivity level in air, soil and food. Results: The total radioactivity, concentrations of 134 I and 134,137 Cs in environmental media was far lower than the limit values specified by the national standard GB. Conclusion: The radioactivity level in Suzhou City is at the natural background level. The individual annual average effective dose for adults in that period caused by ingestion 134,137 Cs in food is 4.41 x 10 -4 mSv/a

Model, parameter and code of environmental dispersion of gaseous effluent under normal operation from nuclear power plant with 600 MWe

International Nuclear Information System (INIS)

Hu Erbang; Gao Zhanrong

1998-06-01

The model of environmental dispersion of gaseous effluence under normal operation from a nuclear power plant with 600 MWe is established to give a mathematical expression of annual mean atmospheric dispersion factor under mixing release condition based on quality assessment of radiological environment for 30 years of Chinese nuclear industry. In calculation, the impact from calm and other following factors have been taken into account: mixing layer, dry and wet deposition, radioactive decay and buildings. The doses caused from the following exposure pathways are also given by this model: external exposure from immersion cloud and ground deposition, internal exposure due to inhalation and ingestion. The code is named as ROULEA. It contains four modules, i.e. INPUT, ANRTRI, CHIQV and DOSE for calculating 4-dimension joint frequency, annual mean atmospheric dispersion factor and doses

Challenging the Ideology of Normal in Schools

Science.gov (United States)

Annamma, Subini A.; Boelé, Amy L.; Moore, Brooke A.; Klingner, Janette

2013-01-01

In this article, we build on Brantlinger's work to critique the binary of normal and abnormal applied in US schools that create inequities in education. Operating from a critical perspective, we draw from Critical Race Theory, Disability Studies in Education, and Cultural/Historical Activity Theory to build a conceptual framework for…

Single-event transients (SET) in analog circuits

International Nuclear Information System (INIS)

Chen Panxun; Zhou Kaiming

2006-01-01

A new phenomenon of single- event upset is introduced. The transient signal is produced in the output of analog circuits after a heavy ion strikes. The transient upset can influence the circuit connected with the output of analog circuits. For example, the output of operational amplifier can be connected with the input of a digital counter, and the pulse of sufficiently high transient output induced by an ion can increase counts of the counter. On the other hand, the transient voltage signal at the output of analog circuits can change the stage of other circuits. (authors)

Superconducting versus normal conducting cavities

CERN Document Server

Podlech, Holger

2013-01-01

One of the most important issues of high-power hadron linacs is the choice of technology with respect to superconducting or room-temperature operation. The favour for a specific technology depends on several parameters such as the beam energy, beam current, beam power and duty factor. This contribution gives an overview of the comparison between superconducting and normal conducting cavities. This includes basic radiofrequency (RF) parameters, design criteria, limitations, required RF and plug power as well as case studies.

Operation and maintenance of 1MW PUSPATI TRIGA reactor

International Nuclear Information System (INIS)

Adnan Bokhari; Mohammad Suhaimi Kassim

2006-01-01

The Malaysian Research Reactor, Reactor TRIGA PUSPATI (RTP) has been successfully operated for 22 years for various experiments. Since its commissioning in June 1982 until December 2004, the 1MW pool-type reactor has accumulated more than 21143 hours of operation, corresponding to cumulative thermal energy release of about 14083 MW-hours. The reactor is currently in operation and normally operates on demand, which is normally up to 6 hours a day. Presently the reactor core is made up of standard TRIAGA fuel element consists of 8.5 wt%, 12 wt% and 20 wt% types; 20%-enriched and stainless steel clad. Several measures such as routine preventive maintenance and improving the reactor support systems have been taken toward achieving this long successful operation. Besides normal routine utilization like other TRIGA reactors, new strategies are implemented for effective increase in utilization. (author)

Seismic transmission operator reciprocity - II: impedance-operator symmetry via elastic lateral modes

Science.gov (United States)

Thomson, C. J.

2015-08-01

The properties of the overburden transmission response are of particular interest for the analysis of reflectivity illumination or blurring in seismic depth imaging. The first step to showing a transmission-operator reciprocity property is to identify the symmetry of the so-called displacement-to-traction operators. The latter are analogous to Dirichlet-to-Neumann operators and they may also be called impedance operators. Their symmetry is deduced here after development of a formal spectral or modal theory of lateral wavefunctions in a laterally heterogeneous generally anisotropic elastic medium. The elastic lateral modes are displacement-traction 6-vectors and they are built from two auxiliary 3-vector lateral-mode bases. These auxiliary modes arise from Hermitian and anti-Hermitian operators, so they have familiar properties such as orthogonality. There is no assumption of down/up symmetry of the elasticity tensor, but basic assumptions are made about the existence and completeness of the elastic modes. A point-symmetry property appears and plays a central role. The 6-vector elastic modes have a symplectic orthogonality property, which facilitates the development of modal expansions for 6-vector functions of the lateral coordinates when completeness is assumed. While the elastic modal theory is consistent with the laterally homogeneous case, numerical work would provide confidence that it is correct in general. An appendix contains an introductory overview of acoustic lateral modes that were studied by other authors, given from the perspective of this new work. A distinction is drawn between unit normalization of scalar auxiliary modes and a separate energy-flux normalization of 2-vector acoustic modes. Neither is crucial to the form of acoustic pressure-to-velocity or impedance operators. This statement carries over to the elastic case for the 3-vector auxiliary- and 6-vector elastic-mode normalizations. The modal theory is used to construct the kernel of the

Diffusion Strategy-Based Distributed Operation of Microgrids Using Multiagent System

Directory of Open Access Journals (Sweden)

Van-Hai Bui

2017-07-01

Full Text Available In distributed operation, each unit is operated by its local controller instead of using a centralized controller, which allows the action to be based on local information rather than global information. Most of the distributed solutions have implemented the consensus method, however, convergence time of the consensus method is quite long, while diffusion strategy includes a stochastic gradient term and can reach convergence much faster compared with consensus method. Therefore, in this paper, a diffusion strategy-based distributed operation of microgrids (MGs is proposed using multiagent system for both normal and emergency operation modes. In normal operation, the MG system is operated by a central controller instead of the distributed controller to minimize the operation cost. If any event (fault occurs in the system, MG system can be divided into two parts to isolate the faulty region. In this case, the MG system is changed to emergency operation mode. The normal part is rescheduled by the central controller while the isolated part schedules its resources in a distributed manner. The isolated part carries out distributed communication using diffusion between neighboring agents for optimal operation of this part. The proposed method enables peer-to-peer communication among the agents without the necessity of a centralized controller, and simultaneously performs resource optimization. Simulation results show that the system can be operated in an economic way in both normal operation and emergency operation modes.

[Pre-operation evaluation and intra-operation management of cochlear implantation].

Science.gov (United States)

Zhang, Dao-xing; Hu, Bao-hua; Xiao, Yu-li; Shi, Bo-ning

2004-10-01

To summarize pre-operation evaluation experiences in cochlear implantation. Performing auditory evaluation and image analysis seriously in 158 severe hearing loss or total deaf cases before cochlear implantation, comparing their performance with the findings during and post operation. Among the total 158 cases, 116 cases with normal structure, 42 cases with the abnormal findings of the inner or middle ear. Stapedial gusher happened in 6 cases, 1 case was not predicted before operation. Except 1 case with serious malformation, the findings of other 157 cases in operation were consistent with the pre-operation evaluation. We helped all patients reconstruct auditory conduction with cochlear implantation, and the average hearing level up to 37.6 dB SPL. Performing image analysis seriously before operation and planning for operation according to HRCT can do great help to cochlear implantation. The operation under the HRCT instruction has less complications.

The research on AP1000 nuclear main pumps’ complete characteristics and the normalization method

International Nuclear Information System (INIS)

Zhu, Rongsheng; Liu, Yong; Wang, Xiuli; Fu, Qiang; Yang, Ailing; Long, Yun

2017-01-01

Highlights: • Complete characteristics of main pump are researched into. • The quadratic character of head and torque under some operatings. • The characteristics tend to be the same under certain conditions. • The normalization method gives proper estimations on external characteristics. • The normalization method can efficiently improve the security computing. - Abstract: The paper summarizes the complete characteristics of nuclear main pumps based on experimental results and makes a detailed study, and then draws a series of important conclusions: with regard to the overall flow area, the runaway operating and 0-revolving-speed operating of nuclear main pumps both have quadratic characteristics; with regard to the infinite flow, the braking operation and the 0-revolving-speed operation show consistent external characteristics. To remedy the shortcomings of the traditional complete-characteristic expression with regards to only describing limited flow sections at specific revolving speeds, the paper proposes a normalization method. As an important boundary condition of the security computing of unstable transient process of the primary reactor coolant pump and the nuclear island primary circuit and secondary circuit, the precision of complete-characteristic data and curve impacts the precision of security computing. A normalization curve obtained by applying the normalization method to process complete-characteristic data could correctly, completely and precisely express the complete characteristics of the primary reactor coolant pump under any rotational speed and full flow, and is capable of giving proper estimations on external characteristics of the flow outside the test range and even of the infinite flow. These advantages are of great significance for the improvement of security computing of transient processes of the primary reactor coolant pump and the circuit system.

Not normally manned compression platforms for the North Sea

International Nuclear Information System (INIS)

Kumaran, K.S.

1994-01-01

Gas turbine driven gas compressors have been widely used on manned offshore facilities. Similarly unmanned gas turbine driven compressor stations have been in operation onshore with major gas transmission companies in Europe, North America and elsewhere. This paper summarizes a recent joint industry study to investigate the technical and economic feasibility of Not Normally Manned (NNM) Offshore Compression Facilities in terms of reliability, availability and maintainability. Classification of not normally manned (or unmanned) offshore facilities in the UK North Sea is in accordance with HSE Operations Notice 8. ON8 specifies criteria for offshore visits, visit hours and number of personnel on board for the operation of NNM platforms. This paper describes a typical Southern North Sea gas platform being considered for NNM compressor application. The conclusions from the study was that NNM compression is technically feasible with the facilities being able to provide an availability in excess of 98%. Life cycle costs were of the order of 70% of manned facilities thus significantly improving field development economics

Intra-operative Vector Flow Imaging Using Ultrasound of the Ascending Aorta among 40 Patients with Normal, Stenotic and Replaced Aortic Valves

DEFF Research Database (Denmark)

Hansen, Kristoffer Lindskov; Møller-Sørensen, Hasse; Kjaergaard, Jesper

2016-01-01

Stenosis of the aortic valve gives rise to more complex blood flows with increased velocities. The angleindependent vector flow ultrasound technique transverse oscillation was employed intra-operatively on the ascending aorta of (I) 20 patients with a healthy aortic valve and 20 patients with aor...... replacement corrects some of these changes. Transverse oscillation may be useful for assessment of aortic stenosis and optimization of valve surgery. (E-mail: lindskov@gmail.com) 2016 World Federation for Ultrasound in Medicine & Biology...... with aortic stenosis before (IIa) and after (IIb) valve replacement. The results indicate that aortic stenosis increased flow complexity (p , 0.0001), induced systolic backflow (p , 0.003) and reduced systolic jet width (p , 0.0001). After valve replacement, the systolic backflow and jet width were normalized...

A measure disintegration approach to spectral multiplicity for normal operators

OpenAIRE

Ay, Serdar

2012-01-01

Ankara : The Department of Mathematics and the Graduate School of Engineering and Science of Bilkent University, 2012. Thesis (Master's) -- Bilkent University, 2012. Includes bibliographical references leaves 44-45. In this thesis we studied the notion of direct integral Hilbert spaces, first introduced by J. von Neumann, and the closely related notion of decomposable operators, as defined in Kadison and Ringrose [1997] and Abrahamse and Kriete [1973]. Examples which show th...

Normal postperative computed tomography findings after avariety of pancreatic surgeries

Energy Technology Data Exchange (ETDEWEB)

Seo, Ji Won; Hwang, Ho Kyoung; Lee, Min Wook; Kim, Ki Whang; Kang, Chang Moo; Kim, Myeong Jin; Chung, Yong Eun [Yonsei University College of Medicine, Seoul (Korea, Republic of)

2017-04-15

Pancreatic surgery remains the only curative treatment for pancreatic neoplasms, and plays an important role in the management of medically intractable diseases. Since the original Whipple operation in the 20th century, surgical techniques have advanced, resulting in decreased postoperative complications and better clinical outcomes. Normal postoperative imaging findings vary greatly depending on the surgical technique used. Radiologists are required to be familiar with the normal postoperative imaging findings, in order to distinguish from postoperative complications or tumor recurrence. In this study, we briefly review a variety of surgical techniques for the pancreas, and present the normal postoperative computed tomography findings.

Considerations in modeling fission gas release during normal operation

International Nuclear Information System (INIS)

Rumble, E.T.; Lim, E.Y.; Stuart, R.G.

1977-01-01

The EPRI LWR fuel rod modeling code evaluation program analyzed seven fuel rods with experimental fission gas release data. In these cases, rod-averged burnups are less than 20,000 MWD/MTM, while the fission gas release fractions range roughly from 2 to 27%. Code results demonstrate the complexities in calculating fission gas release in certain operating regimes. Beyond this work, the behavior of a pre-pressurized PWR rod is simulated to average burnups of 40,000 MWD/MTM using GAPCON-THERMAL-2. Analysis of the sensitivity of fission gas release to power histories and release correlations indicate the strong impact that LMFBR type release correlations induce at high burnup. 15 refs

The development of a model of control room operator cognition

International Nuclear Information System (INIS)

Harrison, C. Felicity

1998-01-01

The nuclear generation station CRO is one of the main contributors to plant performance and safety. In the past, studies of operator behaviour have been made under emergency or abnormal situations, with little consideration being given to the more routine aspects of plant operation. One of the tasks of the operator is to detect the early signs of a problem, and to take steps to prevent a transition to an abnormal plant state. In order to do this CRO must determine that plant indications are no longer in the normal range, and take action to prevent a further move away from normal. This task is made more difficult by the extreme complexity of the control room, and by the may hindrances that the operator must face. It would therefore be of great benefit to understand CRO cognitive performance, especially under normal operating conditions. Through research carried out at several Canadian nuclear facilities we were able to develop a deeper understanding of CRO monitoring of highly automated systems during normal operations, and specifically to investigate the contributions of cognitive skills to monitoring performance. The consultants were asked to develop a deeper understanding of CRO monitoring during normal operations, and specifically to investigate the contributions of cognitive skills to monitoring performance. The overall objective of this research was to develop and validate a model of CRO monitoring. The findings of this research have practical implications for systems integration, training, and interface design. The result of this work was a model of operator monitoring activities. (author)

Phase loop bandwidth measurements on the advanced photon source 352 MHz rf systems

International Nuclear Information System (INIS)

Horan, D.; Nassiri, A.; Schwartz, C.

1997-01-01

Phase loop bandwidth tests were performed on the Advanced Photon Source storage ring 352-MHz rf systems. These measurements were made using the HP3563A Control Systems Analyzer, with the rf systems running at 30 kilowatts into each of the storage ring cavities, without stored beam. An electronic phase shifter was used to inject approximately 14 degrees of stimulated phase shift into the low-level rf system, which produced measureable response voltage in the feedback loops without upsetting normal rf system operation. With the PID (proportional-integral-differential) amplifier settings at the values used during accelerator operation, the measurement data revealed that the 3-dB response for the cavity sum and klystron power-phase loops is approximately 7 kHz and 45 kHz, respectively, with the cavities the primary bandwidth-limiting factor in the cavity-sum loop. Data were taken at various PID settings until the loops became unstable. Crosstalk between the two phase loops was measured

USA/FBR program status FFTF operations startup experience

International Nuclear Information System (INIS)

Moffitt, W.C.; Izatt, R.D.

1981-06-01

This paper gives highlights of the major Operations evaluations and operational results of the startup acceptance testing program and initiation of normal operating cycles for experiment irradiation in the FFTF. 33 figures

A Cost Simulation Tool for Estimating the Cost of Operating Government Owned and Operated Ships

Science.gov (United States)

1994-09-01

Horngren , C.T., Foster, G., Datar, S.M., Cost Accounting : A Management Emphasis, Prentice-Hall, Englewood Cliffs, NJ, 1994 IBM Corporation, A Graphical...4. TITLE AND SUBTITLE A COST SIMULATION TOOL FOR 5. FUNDING NUMBERS ESTIMATING THE COST OF OPERATING GOVERNMENT OWNED AND OPERATED SHIPS 6. AUTHOR( S ...normally does not present a problem to the accounting department. The final category, the cost of operating the government owned and operated ships is

Behavior of U3Si2 Fuel and FeCrAl Cladding under Normal Operating and Accident Reactor Conditions

International Nuclear Information System (INIS)

Gamble, Kyle Allan Lawrence; Hales, Jason Dean; Barani, Tommaso; Pizzocri, Davide; Pastore, Giovanni

2016-01-01

As part of the Department of Energy's Nuclear Energy Advanced Modeling and Simulation program, an Accident Tolerant Fuel High Impact Problem was initiated at the beginning of fiscal year 2015 to investigate the behavior of \\usi~fuel and iron-chromium-aluminum (FeCrAl) claddings under normal operating and accident reactor conditions. The High Impact Problem was created in response to the United States Department of Energy's renewed interest in accident tolerant materials after the events that occurred at the Fukushima Daiichi Nuclear Power Plant in 2011. The High Impact Problem is a multinational laboratory and university collaborative research effort between Idaho National Laboratory, Los Alamos National Laboratory, Argonne National Laboratory, and the University of Tennessee, Knoxville. This report primarily focuses on the engineering scale research in fiscal year 2016 with brief summaries of the lower length scale developments in the areas of density functional theory, cluster dynamics, rate theory, and phase field being presented.

Corticocortical feedback increases the spatial extent of normalization.

Science.gov (United States)

Nassi, Jonathan J; Gómez-Laberge, Camille; Kreiman, Gabriel; Born, Richard T

2014-01-01

Normalization has been proposed as a canonical computation operating across different brain regions, sensory modalities, and species. It provides a good phenomenological description of non-linear response properties in primary visual cortex (V1), including the contrast response function and surround suppression. Despite its widespread application throughout the visual system, the underlying neural mechanisms remain largely unknown. We recently observed that corticocortical feedback contributes to surround suppression in V1, raising the possibility that feedback acts through normalization. To test this idea, we characterized area summation and contrast response properties in V1 with and without feedback from V2 and V3 in alert macaques and applied a standard normalization model to the data. Area summation properties were well explained by a form of divisive normalization, which computes the ratio between a neuron's driving input and the spatially integrated activity of a "normalization pool." Feedback inactivation reduced surround suppression by shrinking the spatial extent of the normalization pool. This effect was independent of the gain modulation thought to mediate the influence of contrast on area summation, which remained intact during feedback inactivation. Contrast sensitivity within the receptive field center was also unaffected by feedback inactivation, providing further evidence that feedback participates in normalization independent of the circuit mechanisms involved in modulating contrast gain and saturation. These results suggest that corticocortical feedback contributes to surround suppression by increasing the visuotopic extent of normalization and, via this mechanism, feedback can play a critical role in contextual information processing.

Design of emergency relief system to flare; Projeto de sistemas de alivio de emergencia para tocha

Energy Technology Data Exchange (ETDEWEB)

Britto, Joelson de Carvalho [PETROBRAS, Rio de Janeiro, RJ (Brazil)

2004-07-01

The relief system has for objective to protect the unit equipment and piping system for high pressures developed during eventual operational upset. As examples of operational upset could mention: human failure (operational mistake - example: inadvertent closure of a block valve), heat exchange tube rupture, utility failure (cooling water, electric power, steam, instrument air) and fire. The relieved products are piping to flare system in order to burn the waste gas. The burned or unburned relieved stream shall be dispersed in order to not to cause damages to the people and the environment. That system should operate automatically without the need of interference of the personnel of the operation. The system is basically constituted of Pressure Safety and Relief Valves (PSVs), piping net, gas-liquid separation vessel, separation vessel residual liquid pump (if necessary) and flare for burning waste gas without liquid. They are necessary also some utilities as fuel gas (to be used as purge gas by flare tip and as fuel gas by pilots in order to guarantee the continuous operation of the flare pilots), electric power, instrument/service air and compressed air or steam (if necessary) to improve the quality of the burns. (author)

NORMALIZATION OF AUTOMOTIVE BRAKE CHARACTERISTICS WHILE OPERATING THEM IN THE REPUBLIC OF BELARUS

Directory of Open Access Journals (Sweden)

I. M. Flerko

2012-01-01

Full Text Available Safety provision for the operated auto-transport facilities is of great significance all over the world. The problem is also considered as an actual one for the automotive transport of theRepublicofBelarus. Provision of higher brake system reliability for the operated vehicles is one of the directions to solve the problem pertaining to improve traffic safety.The paper contains an analysis of basic national standard documents which regulate brake characteristics for the operated vehicles, evaluates checking methods of braking efficiency and vehicle stability at the moment of braking, considers some problems pertaining to methods used for checking and estimation of braking control systems of transport facilities. 

Results of tests under normal and abnormal operating conditions concerning LMFBR fuel element behaviour

International Nuclear Information System (INIS)

Languille, A.; Bergeonneau, P.; Essig, C.; Guerin, Y.

1985-04-01

The objective of this paper is to improve the knowledge on LMFBR fuel element behaviour during protected and unprotected transients in RAPSODIE and PHENIX reactors in order to evaluate its reliability. The range of the tests performed in these reactors is sufficiently large to cover normal and also extreme off normal conditions such as fuel melting. Results of such tests allow to better establish transient design limits for reactor structural components in particular for fuel pin cladding which play a lead role in controlling the accident sequence. Three main topics are emphasized in this paper: fuel melting during slow over-power excursions; influence of the fuel element geometrical evolution on reactivity feedback effects and reactor dynamic behaviour; clad damage evaluation during a transient (essentially very severe loss of flow)

Practical applications of probabilistic structural reliability analyses to primary pressure systems of nuclear power plants

International Nuclear Information System (INIS)

Witt, F.J.

1980-01-01

Primary pressure systems of nuclear power plants are built to exacting codes and standards with provisions for inservice inspection and repair if necessary. Analyses and experiments have demonstrated by deterministic means that very large margins exist on safety impacting failures under normal operating and upset conditions. Probabilistic structural reliability analyses provide additional support that failures of significance are very, very remote. They may range in degree of sophistication from very simple calculations to very complex computer analyses involving highly developed mathematical techniques. The end result however should be consistent with the desired usage. In this paper a probabilistic structural reliability analysis is performed as a supplement to in-depth deterministic evaluations with the primary objective to demonstrate an acceptably low probability of failure for the conditions considered. (author)

States on algebras of unbounded operators

International Nuclear Information System (INIS)

Timmermann, W.

1985-01-01

There are reviewed some of the fundamental results on normal states on algebras of unbounded operators. It is ndicated how these results are related with ideal theory. Few known facts concerning perturbation of normal states are included. There are contained some new results on singular states

Thermal Behavior of Aerospace Spur Gears in Normal and Loss-of-Lubrication Conditions

Science.gov (United States)

Handschuh, Robert F.

2015-01-01

Testing of instrumented spur gears operating at aerospace rotorcraft conditions was conducted. The instrumented gears were operated in a normal and in a loss-of-lubrication environment. Thermocouples were utilized to measure the temperature at various locations on the test gears and a test utilized a full-field, high-speed infrared thermal imaging system. Data from thermocouples was recorded during all testing at 1 hertz. One test had the gears shrouded and a second test was run without the shrouds to permit the infrared thermal imaging system to take data during loss-of-lubrication operation. Both tests using instrumented spur gears were run in normal and loss-of-lubrication conditions. Also the result from four other loss-of-lubrication tests will be presented. In these tests two different torque levels were used while operating at the same rotational speed (10000 revolutions per minute).

The human factor in nuclear reactor operation

International Nuclear Information System (INIS)

Bertron, L.

1982-05-01

The principal operating characteristics of nuclear power plants are summarized. A description of major hazards relating to operator fallibility in normal and abnormal operating conditions is followed by a specific analysis of control room hazards, shift organization and selection and training of management personnel

Operations space diagram for ECRH and ECCD

DEFF Research Database (Denmark)

Bindslev, H.

2004-01-01

at the design phase. At the operations phase it may also prove useful in setting up experimental scenarios by showing operational possibilities, avoiding the need for survey type ray-tracing at the initial planning stages. The diagram may also serve the purpose of communicating operational possibilities to non......A Clemmov-Mullaly-Allis (CMA) type diagram, the ECW-CMA diagram, for representing the operational possibilities of electron cyclotron heating and current drive (ECRH/ECCD) systems for fusion plasmas is presented. In this diagram, with normalized density and normalized magnetic field coordinates......, the parameter range in which it is possible to achieve a given task (e.g. O-mode current drive for stabilizing a neoclassical tearing mode) appears as a region. With also the Greenwald density limit shown, this diagram condenses the information on operational possibilities, facilitating the overview required...

Automation system for operation of nuclear power plant

International Nuclear Information System (INIS)

Kinoshita, Mitsuo; Fukuzaki, Koji; Kato, Kanji

1991-01-01

The automation system comprises a general monitor control device incorporating a plurality of emergency operation plannings concerning an automatic processing, and judging whether the operation is to be conducted or not depending on the plannings based on the data planed by a plant, a control device for controlling the plant in accordance with the planning when monitor control device judges that the operation should be done due to the emergency operation plannings and an operation planning device aiding the formation of the operation plannings. When the state of the power plant exceeds a normal control region, the reactor power is lowered automatically by so much as a predetermined value or to a predetermined level, to automatically return the plant state to the normal control region. In this way, the plant operation efficiency can be improved. Further, after automatic operation, since operation plannings for recovering original operation plannings are prepared efficiently and recovered operation plannings are started in a short period of time, the operators' burden can be mitigated and power saving can be attained. (N.H.)

Performance of iron–chromium–aluminum alloy surface coatings on Zircaloy 2 under high-temperature steam and normal BWR operating conditions

Energy Technology Data Exchange (ETDEWEB)

Zhong, Weicheng; Mouche, Peter A.; Han, Xiaochun [University of Illinois, Department of Nuclear, Radiological, and Plasma Engineering, Urbana, IL 61801 (United States); Heuser, Brent J., E-mail: bheuser@illinois.edu [University of Illinois, Department of Nuclear, Radiological, and Plasma Engineering, Urbana, IL 61801 (United States); Mandapaka, Kiran K.; Was, Gary S. [University of Michigan, Department of Nuclear Engineering and Radiological Sciences, Ann Arbor, MI 48109 (United States)

2016-03-15

Iron-chromium-aluminum (FeCrAl) coatings deposited on Zircaloy 2 (Zy2) and yttria-stabilized zirconia (YSZ) by magnetron sputtering have been tested with respect to oxidation weight gain in high-temperature steam. In addition, autoclave testing of FeCrAl-coated Zy2 coupons under pressure-temperature-dissolved oxygen coolant conditions representative of a boiling water reactor (BWR) environment has been performed. Four different FeCrAl compositions have been tested in 700 °C steam; compositions that promote alumina formation inhibited oxidation of the underlying Zy2. Parabolic growth kinetics of alumina on FeCrAl-coated Zy2 is quantified via elemental depth profiling. Autoclave testing under normal BWR operating conditions (288 °C, 9.5 MPa with normal water chemistry) up to 20 days demonstrates observable weight gain over uncoated Zy2 simultaneously exposed to the same environment. However, no FeCrAl film degradation was observed. The 900 °C eutectic in binary Fe–Zr is addressed with the FeCrAl-YSZ system. - Graphical abstract: Weight gain normalized to total sample surface area versus time during 700 °C steam exposure for FeCrAl samples with different composition (A) and Fe/Cr/Al:62/4/34 (B). In both cases, the responses of uncoated Zry2 (Zry2-13A and Zry2-19A) are shown for comparison. This uncoated Zry2 response shows the expected pre-transition quasi-cubic kinetic behavior and eventual breakaway (linear) kinetics. Highlights: • FeCrAl coatings deposited on Zy2 have been tested with respect to oxidation in high-temperature steam. • FeCrAl compositions promoting alumina formation inhibited oxidation of Zy2 and delay weight gain. • Autoclave testing to 20 days of coated Zy2 in a simulated BWR environment demonstrates minimal weight gain and no film degradation. • The 900 °C eutectic in binary Fe-Zr is addressed with the FeCrAl-YSZ system.

Normal-Mode Splitting in a Weakly Coupled Optomechanical System

Science.gov (United States)

Rossi, Massimiliano; Kralj, Nenad; Zippilli, Stefano; Natali, Riccardo; Borrielli, Antonio; Pandraud, Gregory; Serra, Enrico; Di Giuseppe, Giovanni; Vitali, David

2018-02-01

Normal-mode splitting is the most evident signature of strong coupling between two interacting subsystems. It occurs when two subsystems exchange energy between themselves faster than they dissipate it to the environment. Here we experimentally show that a weakly coupled optomechanical system at room temperature can manifest normal-mode splitting when the pump field fluctuations are antisquashed by a phase-sensitive feedback loop operating close to its instability threshold. Under these conditions the optical cavity exhibits an effectively reduced decay rate, so that the system is effectively promoted to the strong coupling regime.

76 FR 36864 - Special Conditions: Gulfstream Model GVI Airplane; Operation Without Normal Electric Power

Science.gov (United States)

2011-06-23

... Normal Electric Power AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final special... Interface Branch, ANM-111, Transport Standards Staff, Transport Airplane Directorate, Aircraft Certification... Model GVI airplane will be an all-new, two- engine jet transport airplane. The maximum takeoff weight...

Experience in scientific guidance during start-up and normal operation of NPPs with WWER reactors; Opyt nauchnogo rukovodstva puskom i soprovozhdeniya pri ehkspluatatsii ehnergoblokov AEhS s WWER

Energy Technology Data Exchange (ETDEWEB)

Abagyan, A; Kazakov, V; Kryakvin, L [All-Russian Inst. for NPP Operation, Moscow (Russian Federation)

1996-12-31

The experience gained in the All-Russian Research Institute of NPP Operation (RU) in improvement of reactor start-up and normal operation of NPPs has been reported. The work was carried out on NPPs in Russia, Ukraine, Bulgaria, Hungary and Czechoslovakia. All scientific programmes applied use the system approach, modern methods of safety assessment and the principle of loss effect optimization. For the Kozloduy NPP the following projects have been implemented: design of accelerated unloading system for WWER-1000; refinement of water feeding unit for the WWER-1000 steam generator; response analysis of the safety anti-breakdown system of the second loop. The importance of technical substantiation in the process of decision making is stressed. 6 refs.

Cholecystectomy without Operative Cholangiography. | Sule | East ...

African Journals Online (AJOL)

Serum bilirubin, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase were increased 7.8, 1.6, 2.95 and 3.85 times beyond their average normal reference values. The mean CBD diametter was 1.74cm. All CBDS were palpated at operation. Serum amylase was normal in all our patients including ...

The anti-CO2 tax upsets the automotive fleets management. Car makers must adapt themselves. Deluxe cars spared. Small and medium size companies tempted by the long duration rental. At Biogen, medical visitors chose their vehicle

International Nuclear Information System (INIS)

Larmor, P.

2006-01-01

Since the beginning of the year 2006, the pollution level is now taken into consideration in the calculation of the society vehicles tax. This measure completely upsets the management and allocation rules of provided cars. Therefore, the government foresees to relax its position. Car makers will have to propose new versions of their models with pollution levels in agreement with the tax categories imposed by the new regulation. Small and medium size companies are now tempted by long duration car rental contracts. Therefore, car rental companies foresee interesting opportunities with this fiscality stiffening. This press-kit analyzes the situation from the different points of view: fleet managers, car makers, users, company managers, car hirers. (J.S.)

Corticocortical feedback increases the spatial extent of normalization

Science.gov (United States)

Nassi, Jonathan J.; Gómez-Laberge, Camille; Kreiman, Gabriel; Born, Richard T.

2014-01-01

Normalization has been proposed as a canonical computation operating across different brain regions, sensory modalities, and species. It provides a good phenomenological description of non-linear response properties in primary visual cortex (V1), including the contrast response function and surround suppression. Despite its widespread application throughout the visual system, the underlying neural mechanisms remain largely unknown. We recently observed that corticocortical feedback contributes to surround suppression in V1, raising the possibility that feedback acts through normalization. To test this idea, we characterized area summation and contrast response properties in V1 with and without feedback from V2 and V3 in alert macaques and applied a standard normalization model to the data. Area summation properties were well explained by a form of divisive normalization, which computes the ratio between a neuron's driving input and the spatially integrated activity of a “normalization pool.” Feedback inactivation reduced surround suppression by shrinking the spatial extent of the normalization pool. This effect was independent of the gain modulation thought to mediate the influence of contrast on area summation, which remained intact during feedback inactivation. Contrast sensitivity within the receptive field center was also unaffected by feedback inactivation, providing further evidence that feedback participates in normalization independent of the circuit mechanisms involved in modulating contrast gain and saturation. These results suggest that corticocortical feedback contributes to surround suppression by increasing the visuotopic extent of normalization and, via this mechanism, feedback can play a critical role in contextual information processing. PMID:24910596

Method for the determination of technical specifications limiting temperature in EBR-II operation

International Nuclear Information System (INIS)

Chang, L.K.; Hill, D.J.; Ku, J.Y.

2004-01-01

The methodology and analysis procedure to qualify the Mark-V and Mark-VA fuels for the Experimental Breeder Reactor II are summarized in this paper. Fuel performance data and design safety criteria are essential for thermal-hydraulic analyses and safety evaluations. Normal and off-normal operation duty cycles and transient classifications are required for the safety assessment of the fuels. Design safety criteria for steady-state normal and transient off-normal operations were developed to ensure structural integrity of the fuel pin. The maximum allowable coolant outlet temperatures and powers of subassemblies for steady-state normal operation conditions were first determined in a row-by-row basis by a thermal-hydraulic and fuel damage analysis, in which a trial-and-error approach was used to predict the maximum subassembly coolant outlet temperatures and powers that satisfy the design safety criteria for steady-state normal operation conditions. The limiting steady-state temperature and power were then used as the initial subassembly thermal conditions for the off-normal transient analysis to assess the safety performance of the fuel pin for anticipated, unlikely and extremely unlikely events. If the design safety criteria for the off-normal events are not satisfied, then the initial steady-state subassembly temperatures and/or powers are reduced and an iterative procedure is employed until the design safety criteria for off-normal conditions are satisfied, and the initial subassembly outlet coolant temperature and power are the technical specification limits for reactor operation. (author)

Problems in ensuring normal actuation of pneumatic drilling machines during their manufacture

Energy Technology Data Exchange (ETDEWEB)

Vasilev, V

1982-01-01

The problems of ensuring normal actuation and reliable operation of pneumatic drilling machines during their manufacturing are examined. The modes of operation are cited with which the normal actuation must be tested. Oscillograms are used to examine the characteristic cases of completion of machines with the impossibility of actuation during operation for one cycle or with an interruption in the mode, along with methods for eliminating these deficiencies. The effect on the actuation process of factors such as the type of rock being drilled, the change in the position of the machine, the axial force, the design of the air distribution device and the impact mechanism, the relationship between the surface areas of the distribution device and the travel of the distributor, the choking of the power and so on is studied. Different methods for completing design are analyzed.

Energy efficiency estimation of a steam powered LNG tanker using normal operating data

Directory of Open Access Journals (Sweden)

Sinha Rajendra Prasad

2016-01-01

Full Text Available A ship’s energy efficiency performance is generally estimated by conducting special sea trials of few hours under very controlled environmental conditions of calm sea, standard draft and optimum trim. This indicator is then used as the benchmark for future reference of the ship’s Energy Efficiency Performance (EEP. In practice, however, for greater part of operating life the ship operates in conditions which are far removed from original sea trial conditions and therefore comparing energy performance with benchmark performance indicator is not truly valid. In such situations a higher fuel consumption reading from the ship fuel meter may not be a true indicator of poor machinery performance or dirty underwater hull. Most likely, the reasons for higher fuel consumption may lie in factors other than the condition of hull and machinery, such as head wind, current, low load operations or incorrect trim [1]. Thus a better and more accurate approach to determine energy efficiency of the ship attributable only to main machinery and underwater hull condition will be to filter out the influence of all spurious and non-standard operating conditions from the ship’s fuel consumption [2]. The author in this paper identifies parameters of a suitable filter to be used on the daily report data of a typical LNG tanker of 33000 kW shaft power to remove effects of spurious and non-standard ship operations on its fuel consumption. The filtered daily report data has been then used to estimate actual fuel efficiency of the ship and compared with the sea trials benchmark performance. Results obtained using data filter show closer agreement with the benchmark EEP than obtained from the monthly mini trials . The data filtering method proposed in this paper has the advantage of using the actual operational data of the ship and thus saving cost of conducting special sea trials to estimate ship EEP. The agreement between estimated results and special sea trials EEP is

A comparison of vowel normalization procedures for language variation research

Science.gov (United States)

Adank, Patti; Smits, Roel; van Hout, Roeland

2004-11-01

An evaluation of vowel normalization procedures for the purpose of studying language variation is presented. The procedures were compared on how effectively they (a) preserve phonemic information, (b) preserve information about the talker's regional background (or sociolinguistic information), and (c) minimize anatomical/physiological variation in acoustic representations of vowels. Recordings were made for 80 female talkers and 80 male talkers of Dutch. These talkers were stratified according to their gender and regional background. The normalization procedures were applied to measurements of the fundamental frequency and the first three formant frequencies for a large set of vowel tokens. The normalization procedures were evaluated through statistical pattern analysis. The results show that normalization procedures that use information across multiple vowels (``vowel-extrinsic'' information) to normalize a single vowel token performed better than those that include only information contained in the vowel token itself (``vowel-intrinsic'' information). Furthermore, the results show that normalization procedures that operate on individual formants performed better than those that use information across multiple formants (e.g., ``formant-extrinsic'' F2-F1). .

Determination of the potential radiation exposure of the population close to the Asse II mine caused by deduction of radioactive substances with the discharge air in the normal operation using the ''Atmospheric Radionuclide-Transport-Model'' (ARTM)

International Nuclear Information System (INIS)

Esch, D.; Wittwer, C.

2014-01-01

Between 1967 and 1978 125.787 packages filled with low-level and intermediate-level radioactive waste were emplaced in the mining plant Asse II. Volatile radioactive substances like H-3, C-14 and Rn-222 are released from the emplaced waste. These substances reach the ventilated parts of the mine and are released with the discharge air. The potential radiation exposure of the population caused by deduction of radioactive substances with the discharge air in the normal operation is determined by the ''Atmospheric Radionuclide-Transport-Model'' (ARTM). As result the maximal deductions of volatile radioactive substances with the discharge air in the normal operation of the Asse II mine lead to radiation exposure of the population, which is considerably lower than the permissible values of application rate.

14 CFR 23.237 - Operation on water.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Operation on water. 23.237 Section 23.237... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 23.237 Operation on water. A wave height, demonstrated to be safe for operation, and any...

Radioactive effluents from CANDU 6 reactors during normal operation

International Nuclear Information System (INIS)

Boss, C.R.; Allsop, P.J.

1995-12-01

During routine operation of a CANDU 6 reactor, various gaseous, liquid, and solid radioactive wastes are generated. The layout of the CANDU 6 reactor and the design of its systems ensure that these are minimized, but small quantities of gaseous and liquid wastes are continually discharged at very low concentrations. This report discusses the make-up of these chronically generated gaseous and liquid effluents. From a safety perspective, the doses to individual members of the public resulting from radioactive wastes chronically discharged from CANDU 6 reactors have been negligible. Similarly, doses to the regional and global populations have been negligible, generally less than 0.001% of background. While far below regulatory limits, releases of tritium, noble gases and gross β - -γ have been the most radiologically significant emissions, while radioiodine and particulates have had the greatest potential to deliver public dose. (author). 8 refs., 16 tabs., 3 figs

The normalization heuristic: an untested hypothesis that may misguide medical decisions.

Science.gov (United States)

Aberegg, Scott K; O'Brien, James M

2009-06-01

Medical practice is increasingly informed by the evidence from randomized controlled trials. When such evidence is not available, clinical hypotheses based on pathophysiological reasoning and common sense guide clinical decision making. One commonly utilized general clinical hypothesis is the assumption that normalizing abnormal laboratory values and physiological parameters will lead to improved patient outcomes. We refer to the general use of this clinical hypothesis to guide medical therapeutics as the "normalization heuristic". In this paper, we operationally define this heuristic and discuss its limitations as a rule of thumb for clinical decision making. We review historical and contemporaneous examples of normalization practices as empirical evidence for the normalization heuristic and to highlight its frailty as a guide for clinical decision making.

Sensor to Detect Aqueous Film Forming Foam (AFFF) in Ship Bilge Water: Construction and Installation

National Research Council Canada - National Science Library

Kirts, Richard

2001-01-01

.... The primary use of the sensor is the detection of AFFF in the bilge water of Navy ships. If AFFF is present in bilge water off-loaded to a shore-side wastewater treatment plant, it may cause serious upsets in treatment plant operation...

Operations space diagram for ECRH and ECCD

International Nuclear Information System (INIS)

Bindslev, Henrik

2004-01-01

A Clemmov-Mullaly-Allis (CMA) type diagram, the ECW-CMA diagram, for representing the operational possibilities of electron cyclotron heating and current drive (ECRH/ECCD) systems for fusion plasmas is presented. In this diagram, with normalized density and normalized magnetic field coordinates, the parameter range in which it is possible to achieve a given task (e.g. O-mode current drive for stabilizing a neoclassical tearing mode) appears as a region. With also the Greenwald density limit shown, this diagram condenses the information on operational possibilities, facilitating the overview required at the design phase. At the operations phase it may also prove useful in setting up experimental scenarios by showing operational possibilities, avoiding the need for survey type ray-tracing at the initial planning stages. The diagram may also serve the purpose of communicating operational possibilities to non-experts. JET and ITER like plasmas are used, but the method is generic. (author)

The proposals on cooperation to foreign centers of science on thermophysical properties of reactor materials in a broad band of pressure and temperatures realized at normal transient and emergency operation activity of nuclear power plants

International Nuclear Information System (INIS)

Fortov, V.E.

1996-01-01

The proposals on cooperation in the area of thermophysical properties of reactor materials in a broad band of pressure and temperature realized at normal transient and emergency operation activity of nuclear power plants are discussed. 1 fig

Normal zone propagation characteristics of coated conductor according to insulation materials

International Nuclear Information System (INIS)

Yang, S.E.; Ahn, M.C.; Park, D.K.; Chang, K.S.; Bae, D.K.; Ko, T.K.

2007-01-01

Recent development of CC, usually called second generation (2G) HTS, is actively in progress. Because of its higher critical current density as well as higher n-value, 2G HTS is feasible for the applications such as superconducting fault current limiter and superconducting cable. For operating the HTS equipment stably, it needs to investigate the characteristics of normal zone propagation occurred by quench. Investigations on the fundamental characteristics can be one of the indispensable foundations for research and development of power equipments. In this paper, normal zone propagation (NZP) characteristics according to various insulation materials are researched. By heating with NiCr heater and insulating with epoxy, we applied the operating current with respect to the critical current for calculation of minimum quench energy (MQE) and measurement of NZP

A New One-Pass Transformation into Monadic Normal Form

DEFF Research Database (Denmark)

Danvy, Olivier

2003-01-01

We present a translation from the call-by-value λ-calculus to monadic normal forms that includes short-cut boolean evaluation. The translation is higher-order, operates in one pass, duplicates no code, generates no chains of thunks, and is properly tail recursive. It makes a crucial use of symbolic...

Approach to normalization of the secondary circuit water chemistry of NPP with WWER-1000

International Nuclear Information System (INIS)

Mamet, V.A.; Erpyleva, S.F.; Banyuk, G.F.

1998-01-01

The approach to normalization if indices of water-chemical regime of the secondary circuit of the NPP with WWER-1000 reactor, based on pH calculational values at the coolant working temperature in dependence on the normalized admixtures concentration is considered. The possibility for conducting the water regime of steam generators by the ratio of sodium concentration and electrical conductivity of H-cation sample of blow-through water is shown. The limitations (os action level) by deviation of normalized indices from recommended ones for normal operational conditions are described

Normal stress Sestamibi study: why re inject?

International Nuclear Information System (INIS)

Unger, S.A.; Hughes, T.

2000-01-01

Full text: Myocardial perfusion imaging (MPI) is widely used for risk stratification of patients with known or suspected coronary artery disease. A normal MPI study predicts an annual cardiac event rate of 99 Tc m -Sestamibi (MIBI), omitting the rest study when the post-stress study is interpreted as normal. The safety of this approach has not been validated, all published reports utilising both rest and stress images to interpret a study as 'normal'. Between 1/1/98 and 30/8/98, 489 patients (patients) were referred to our department for stress MPI. Of these, 237 were interpreted as normal on the basis of their post-stress study, and did not undergo a rest study. 12 month clinical follow-up was available in 184 (78%) of these patients, representing the study group (82 males, 102 females; mean age 61±12 years). 156 of these patients were referred for assessment of chest pain, three for dyspnoea, six for abnormal ECGs, and 19 for pre-operative evaluation. At one year of follow-up, there were no myocardial infarcts or admissions for unstable angina, and no cardiac deaths. Three patients died of non-cardiac causes. Seven patients underwent coronary angiography: five were normal, one had a single 50% stenosis, and one had an 80% vein graft stenosis which was subsequently angioplastied. In conclusion, a normal stress MIBI image predicts an excellent prognosis and negates the need for a rest reinjection study, thus reducing patient camera time and radiation exposure, improving departmental throughput, and minimising public health expenditure. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

The effect of mitomycin C trabeculectomy on the progression of visual field defect in normal-tension glaucoma.

Science.gov (United States)

Hagiwara, Y; Yamamoto, T; Kitazawa, Y

2000-03-01

We investigated in a prospective fashion the visual prognosis and complications in normal-tension glaucoma following unilateral trabeculectomy with adjunctive mitomycin C. Trabeculectomy with adjunctive mitomycin C was carried out unilaterally in 21 cases of normal-tension glaucoma. Intraocular pressure (IOP), visual prognosis, and complications were compared between the operated eyes and the non-operated fellow eyes. The follow-up period ranged from 2 to 7 years. The IOP dropped significantly from 14.8+/-1.8 mmHg (mean +/- SD) to 9.6+/-3.9 mmHg in the operated eyes (P=0.0002, Wilcoxon signed-rank test), but did not drop in the non-operated eyes. The mean deviation (MD) was -12.69+/-6.41 dB preoperatively and -14.70+/-5.49 dB at the last clinic visit in the operated eyes, whereas in non-operated eyes it was -7.85+/-5.65 dB and -11.15+/-5.62 dB, respectively. The MD deteriorated significantly in both operated and non-operated eyes (operated eyes P=0.0239, non-operated eyes: P=0.0002; Wilcoxon signed-rank test). The MD slope was -0.37+/-0.60 dB/year and -0.71+/-0.89 dB/year for the operated and non-operated eyes, respectively (P=0.5243, Mann-Whitney U-test). Visual field deterioration was more frequently observed in the non-operated eyes by a pointwise definition of the progression (Ptest). Visual acuity deteriorated in 6 of the operated eyes and in 5 of the non-operated eyes. Cataract developed in 6 (29%) of the 21 operated eyes, while among the non-operated eyes 4 (19%) developed cataract. Mitomycin C trabeculectomy is effective in delaying progression of visual field defect in normal-tension glaucoma, but complications may arise and cause some visual disturbance.

Clinical Operations Variables are Associated With Blood Pressure Outcomes.

Science.gov (United States)

Kressin, Nancy R; Lasser, Karen E; Paasche-Orlow, Michael; Allison, Jeroan; Ash, Arlene S; Adams, William G; Shanahan, Christopher W; Legler, Aaron; Pizer, Steven D

2015-06-01

Uncontrolled blood pressure (BP), among patients diagnosed and treated for the condition, remains an important clinical challenge; aspects of clinical operations could potentially be adjusted if they were associated with better outcomes. To assess clinical operations factors' effects on normalization of uncontrolled BP. Observational cohort study. Patients diagnosed with hypertension from a large urban clinical practice (2005-2009). We obtained clinical data on BP, organized by person-month, and administrative data on primary care provider (PCP) staffing. We assessed the resolution of an episode of uncontrolled BP as a function of time-varying covariates including practice-level appointment volume, individual clinicians' appointment volume, overall practice-level PCP staffing, and number of unique PCPs. Among the 7409 unique patients representing 50,403 person-months, normalization was less likely for the patients in whom the episode starts during months when the number of unique PCPs were high [the top quintile of unique PCPs was associated with a 9 percentage point lower probability of normalization (Ppercentage point reduction in the probability of normalization (P=0.01)]. Neither clinician appointment volume nor practice clinician staffing levels were significantly associated with the probability of normalization. Findings suggest that clinical operations factors can affect clinical outcomes like BP normalization, and point to the importance of considering outcome effects when organizing clinical care.

Birth defects in perinatal infants in areas contiguous to Hongyanhe Nuclear Power Plant before its normal operation

International Nuclear Information System (INIS)

Zhou Ling; Yin Zhihua; Han Zhonghui

2011-01-01

Objective: To understand the status of birth defects among the perinatal infants in the areas contiguous to Hongyanhe nuclear power plant before its normal operation, so as to provide background information for the evaluation of the impact of nuclear power plant on birth defects. Methods: From 1 October 1995 to 30 September 2009 the midwifery units at second class and above of Wafangdian City were asked to be in charge of recording the birth defects among the perinatal infants born during this period within the range of 50 km around the Hongyanhe nuclear power plant. Results: The total number of birth defects was 697, and the maternal number Was 83779. The average defect rate Was 83.20/10 4 . There were significant differences in the birth defect rate among different years (χ 2 =39.54, P<0.05), however, without linear trend therein,and among the survey areas (χ 2 =15.36, P<0.05) as well. The top five birth defects were congenital heart disease (148 cases), cleft lip with cleft palate (67 cases), congenital hydrocephalus (63 cases), and spina bifida (37 cases) and cleft lip (36 cases). Conclusions: The birth defect rate within the range of 50 km around the Hongyanhe nuclear power plant is lower than that of the region of Liaoning Province and the national rate of birth defects. (authors)

Squeezed State Caused by Inverse of Photon Creation Operator

International Nuclear Information System (INIS)

Xu Xuefen

2006-01-01

Using the photon creation operator's eigenstate theory we derive the normally ordered expansion of inverse of the squeezed creation operator. It turns out that using this operator a kind of excitation on the squeezed vacuum states can be formed.

Overview of HPM Effects in Electronics

International Nuclear Information System (INIS)

Holloway, Michael A.

2012-01-01

The following presentation contains an overview of HPM effects in modern electronics. HPM effects can be categorized into two basic level of effects, which are damaging and non-damaging. Damaging effects include junction breakdowns, dielectric breakdowns, and latch-up. These types of effects render a system inoperable until repaired. With non-damaging effects, HPM signals couple to into system components generating circuit responses that can overwhelm normal operation. Non-damaging effects can temporarily render a system inoperable or cause a system to lock and require a restart. Since modern systems are so complex, fundamental mechanisms of upset in circuit primitives are studied. All topics covered and all figured contained within are found in open literature. All data plots presented were obtained from experimental measurements conducted at the University of Maryland College Park and are also found in the open literature.

Improving CANDU annunciation - Current R and D and future directions

International Nuclear Information System (INIS)

Lupton, L.R.; Feher, M.P.; Davey, E.C.; Guo, K.Q.; Bhuiyan, S.H.

1994-01-01

Annunciation is used to ensure that control room staff are promptly alerted to important changes in plant conditions that may impact on safety and production goals. We are carrying out research and development to improve CANDU annunciation, in partnership with Canadian CANDU utility and design organizations. The main goal is to solve the ''information overload'' problem that occurs during major plant upsets, while providing operators with annunciation information needed to prevent, mitigate, and accommodate plant disturbances. To data, a set of annunciation concepts has been developed based on operational needs in a complex supervisory control environment. A prototype annunciation system has been developed and demonstrated with Point Lepreau Generating Station operations staff. Preliminary evaluations show that the system has the potential to solve many of the current problems associated with upset management. Further evaluation of this system is planned for 1994/95. This paper summarizes the project, including the current status, lessons learned to data, future directions of the research, and implementation by plants. (author). 9 refs, 3 figs, 1 tab

Infiltration with lidocaine and adrenaline instead of normal saline does not improve the septoplasty procedure.

Science.gov (United States)

Gungor, Volkan; Baklaci, Deniz; Kum, Rauf Oguzhan; Yilmaz, Yavuz Fuat; Ozcan, Muge; Unal, Adnan

2016-08-01

The aim of this study was to determine whether infiltration of local anesthetics with adrenaline improved septoplasty procedure when compared to normal saline. Eight-two patients undergoing septoplasty were randomized into two groups. In group 1, septal mucoperichondrium was infiltrated with lidocaine with adrenaline, and normal saline was used in group 2. Presence of intra-operative septal mucosal injuries, the amount of bleeding, arterial blood pressure, operation time as well as the quality of the surgical field and the convenience of finding the correct surgical plane as determined by the surgeon using a 5-point scale were compared between two groups. There were no significant differences for the amount of blood loss, mean arterial pressure, operation time, or scores for convenience of finding the correct surgical plane between the two groups. There was no significant difference for intra-operative simple (P = 0.631) and total (simple+severe) (P = 0.649) septal mucoperichondrial injuries between groups 1 and 2, either. However, severe mucoperichondrial injury rate was higher in the patients infiltrated with lidocaine and adrenaline (P = 0.026), and the quality of the surgical field was worse in the patients injected with normal saline (P = 0.0179). Infiltration of septal mucoperichondrium with lidocaine and adrenaline instead of normal saline was not advantageous in terms of objective parameters tested, including bleeding amount and duration of surgery as well as the of the total mucosal injury rate in septoplasty procedure.

The renormalization of several composite operator insertions, Wilson expansions of composite operators, and the applications to short-distance behaviour

International Nuclear Information System (INIS)

Collecott, P.S.

1978-01-01

The renormalization of composite operator insertions is examined within a normal product framework, and various identities between composite operator insertions are proved. In particular a proof of the Wilson expansion of composite operators in the presence of other composite operators is given. The analysis necessitates a re-examination of several physical processes, and it is shown in particular why the results for deep inelastic scattering still hold. (Auth.)

Normalization of cell responses in cat striate cortex

Science.gov (United States)

Heeger, D. J.

1992-01-01

Simple cells in the striate cortex have been depicted as half-wave-rectified linear operators. Complex cells have been depicted as energy mechanisms, constructed from the squared sum of the outputs of quadrature pairs of linear operators. However, the linear/energy model falls short of a complete explanation of striate cell responses. In this paper, a modified version of the linear/energy model is presented in which striate cells mutually inhibit one another, effectively normalizing their responses with respect to stimulus contrast. This paper reviews experimental measurements of striate cell responses, and shows that the new model explains a significantly larger body of physiological data.

Clarifying Normalization

Science.gov (United States)

Carpenter, Donald A.

2008-01-01

Confusion exists among database textbooks as to the goal of normalization as well as to which normal form a designer should aspire. This article discusses such discrepancies with the intention of simplifying normalization for both teacher and student. This author's industry and classroom experiences indicate such simplification yields quicker…

Analysis by Monte Carlo simulations of the sensitivity to single event upset of SRAM memories under spatial proton or terrestrial neutron environment

International Nuclear Information System (INIS)

Lambert, D.

2006-07-01

Electronic systems in space and terrestrial environments are subjected to a flow of particles of natural origin, which can induce dysfunctions. These particles can cause Single Event Upsets (SEU) in SRAM memories. Although non-destructive, the SEU can have consequences on the equipment functioning in applications requiring a great reliability (airplane, satellite, launcher, medical, etc). Thus, an evaluation of the sensitivity of the component technology is necessary to predict the reliability of a system. In atmospheric environment, the SEU sensitivity is mainly caused by the secondary ions resulting from the nuclear reactions between the neutrons and the atoms of the component. In space environment, the protons with strong energies induce the same effects as the atmospheric neutrons. In our work, a new code of prediction of the rate of SEU has been developed (MC-DASIE) in order to quantify the sensitivity for a given environment and to explore the mechanisms of failures according to technology. This code makes it possible to study various technologies of memories SRAM (Bulk and SOI) in neutron and proton environment between 1 MeV and 1 GeV. Thus, MC-DASIE was used with experiment data to study the effect of integration on the sensitivity of the memories in terrestrial environment, a comparison between the neutron and proton irradiations and the influence of the modeling of the target component on the calculation of the rate of SEU. (author)

The normalization of nursing supervision in the comprehensive interventional therapy and diagnosis center

International Nuclear Information System (INIS)

Li Xue; Chen Jinhua; Zhang Weiguo; Wang Yi

2009-01-01

Objective: To discuss the normalization of nursing supervision in the comprehensive interventional therapy and diagnosis center in order to improve the nursing quality and work-efficiency. Methods: The following normalization measures were established: to formulate a new system of administration, to consummate interventional rules and regulations, to normalize various operation process and nursing norms, to design interventional nursing record, to cultivate professional interventional nurses, to establish the transversal connecting interventional nursing model, to enhance the interventional quality control of care, to consummate quality evaluation criterion and to enact unified management of the interventional consumed material by computer. Results: The expertise and skill of nursing personnel was significantly raised. The nursing personnel could assume the assistance and salvage in various large and complicate interventional operation. The nursing quality could meet the professional requirements. The administration of the interventional center gained the cohesive force and the nursing supervision became on the right track, right procedure and scientific principle. The nursing quality and work-efficiency was greatly improved. Conclusion: It is necessary to establish comprehensive interventional center and enforce the normalization of the nursing supervision for the development of the subject of interventional radiology. (authors)

Can FDG PET predict verbal specific memory decline after surgery for left temporal lobe epilepsy when MRI is normal?

International Nuclear Information System (INIS)

Sagona, J.A.; Rowe, C.C.; Thomas, D.; Dickinson-Rowe, K.L.

2002-01-01

Full text: Temporal lobectomy gives excellent control of seizures in over 80% of patients with temporal lobe epilepsy. The left temporal lobe, particularly the left hippocampus, is primarily responsible for verbal memory. In most patients, the hippocampus which lies in the medial temporal lobe is abnormal and can be removed without loss of memory function. However, removal of the left hippocampus when it appears normal on MRI, often causes a significant decline in verbal specific memory (VSM) function. This paper explores the significance of pre-operative FDG-PET asymmetry in temporal lobe metabolism in predicting the VSM outcome after left temporal lobectomy when MRI demonstrates a normal hippocampus. Fifteen patients between 1993 and 2000, underwent left temporal lobectomy including left hippocampal resection, Pre-operatively all patients underwent 1.5T MRI, FDG PET and neuropsychological assessment. Neuropsychological assessment was repeated post-operatively. The left hippocampus was normal on MRI in nine and demonstrated mild T2 signal change without atrophy in six. FDG PET demonstrated temporal lobe hypometabolism in 12 patients. Post-operatively, neuropsychological evaluation documented a decline in verbal specific memory function in six patients, three with normal MRI and three with mild T2 change. We found that all patients with normal FDG PET studies (n=3) demonstrated significant verbal memory deterioration post-operatively. Nine of twelve patients (75%) with left temporal lobe hypometabolism did not show new verbal memory deficits. FDG PET improves the risk stratification for verbal specific memory decline with left temporal lobectomy in patients with normal hippocampi on MRI. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

Human factors review of electric power dispatch control centers. Volume 3. Operator information needs summary. Final report

Energy Technology Data Exchange (ETDEWEB)

Miller, R.J.; Najaf-Zadeh, K.; Darlington, H.T.; McNair, H.D.; Seidenstein, S.; Williams, A.R.

1982-10-01

Human factors is a systems-oriented interdisciplinary specialty concerned with the design of systems, equipment, facilities and the operational environment. An important aspect leading to the design requirements is the determination of the information requirements for electric power dispatch control centers. There are significant differences between the system operator's actions during normal and degraded states of power system operation, and power system restoration. This project evaluated the information the operator requires for normal power system and control system operations and investigates the changes of information required by the operator as the power system and/or the control system degrades from a normal operating state. The Phase II study, published in two volumes, defines power system states and control system conditions to which operator information content can be related. This volume presents a summary of operator information needs, identifying the needs for and the uses of power system information by a system operator in conditions ranging from normal through degraded operation. Training requirements are also included for planning entry-level and follow-on training for operators.

Correlated random sampling for multivariate normal and log-normal distributions

International Nuclear Information System (INIS)

Žerovnik, Gašper; Trkov, Andrej; Kodeli, Ivan A.

2012-01-01

A method for correlated random sampling is presented. Representative samples for multivariate normal or log-normal distribution can be produced. Furthermore, any combination of normally and log-normally distributed correlated variables may be sampled to any requested accuracy. Possible applications of the method include sampling of resonance parameters which are used for reactor calculations.

Determination of engineering safety factor -routine in Hungary (a methodology for the normal operation local power engineering safety factors)

International Nuclear Information System (INIS)

Szecsenyi, Z.; Korpas, L.; Bona, G.; Kereszturi, A.

2010-01-01

From the late nineties Paks Nuclear Power Plant-in collaboration with KFKI Atomic Energy Research Institute (KFKI AEKI)- is developing a system for determining the normal operation local power engineering safety factors. The system is based on a Monte Carlo sampling of the uncertain model input parameters. Additionally, the comparison of the calculation to the in-core measurements plays essential role for determining some important input parameters. By using new fuel types and the corresponding more recent detailed technological data, the applied method is being improved from time to time. Presently, the actually used and authorized engineering safety factors at Paks NPP are determined by using this method. In the paper, the system.s main properties are described (not going beyond the possible extent). The main points are as follows:-Mathematical definition of the engineering safety factor;-Sources of the uncertainties;-Input error propagation method constituting the basis of the system;-Flow-chart of the subsequent steps of the determination Finally, in the paper the engineering safety factors values of some selected parameters are presented as examples for demonstration of the capability of the method. (Authors)

Good alarm design plays a vital role in successful DCS implementation: Hard learned lessons from petrochemical applications

International Nuclear Information System (INIS)

Wilson, C.; Rothenberg, D.

2006-01-01

Nuclear operators are eager to update their automation infrastructure, but are apprehensive due to the consequences of failure. The process industries have learned that alarm design is critical to a successful Distributed Control System (DCS) implementation. This paper shares valuable insight into how alarms play a key role in successful management of upsets, help focus operator attention, and supply critical information during periods of high stress. (authors)

Quantum incompatibility of channels with general outcome operator algebras

Science.gov (United States)

Kuramochi, Yui

2018-04-01

A pair of quantum channels is said to be incompatible if they cannot be realized as marginals of a single channel. This paper addresses the general structure of the incompatibility of completely positive channels with a fixed quantum input space and with general outcome operator algebras. We define a compatibility relation for such channels by identifying the composite outcome space as the maximal (projective) C*-tensor product of outcome algebras. We show theorems that characterize this compatibility relation in terms of the concatenation and conjugation of channels, generalizing the recent result for channels with quantum outcome spaces. These results are applied to the positive operator valued measures (POVMs) by identifying each of them with the corresponding quantum-classical (QC) channel. We also give a characterization of the maximality of a POVM with respect to the post-processing preorder in terms of the conjugate channel of the QC channel. We consider another definition of compatibility of normal channels by identifying the composite outcome space with the normal tensor product of the outcome von Neumann algebras. We prove that for a given normal channel, the class of normally compatible channels is upper bounded by a special class of channels called tensor conjugate channels. We show the inequivalence of the C*- and normal compatibility relations for QC channels, which originates from the possibility and impossibility of copying operations for commutative von Neumann algebras in C*- and normal compatibility relations, respectively.

Final Environmental Statement. Continental United States Over-the- Horizon Backscatter Radar System

Science.gov (United States)

1975-01-01

ment normally found near population centers. Interference generators include railroads, main highways ( automotive ignition systems), power lines...factories, logging activities, welding and any heavy industries which handle switching of high voltage electrical currents. The terrain around the...responsibility to them. I also have a certain respon- sibility to you. I am coming to your community—I am in a way upsetting 128 your applecart. So, I

Hydrotreater/Distillation Column Hazard Analysis Report Rev. 2

Energy Technology Data Exchange (ETDEWEB)

Lowry, Peter P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wagner, Katie A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-04-15

This project Hazard and Risk Analysis Report contains the results of several hazard analyses and risk assessments. An initial assessment was conducted in 2012, which included a multi-step approach ranging from design reviews to a formal What-If hazard analysis. A second What-If hazard analysis was completed during February 2013 to evaluate the operation of the hydrotreater/distillation column processes to be installed in a process enclosure within the Process Development Laboratory West (PDL-West) facility located on the PNNL campus. The qualitative analysis included participation of project and operations personnel and applicable subject matter experts. The analysis identified potential hazardous scenarios, each based on an initiating event coupled with a postulated upset condition. The unmitigated consequences of each hazardous scenario were generally characterized as a process upset; the exposure of personnel to steam, vapors or hazardous material; a spray or spill of hazardous material; the creation of a flammable atmosphere; or an energetic release from a pressure boundary.

Rhythm-based heartbeat duration normalization for atrial fibrillation detection.

Science.gov (United States)

Islam, Md Saiful; Ammour, Nassim; Alajlan, Naif; Aboalsamh, Hatim

2016-05-01

Screening of atrial fibrillation (AF) for high-risk patients including all patients aged 65 years and older is important for prevention of risk of stroke. Different technologies such as modified blood pressure monitor, single lead ECG-based finger-probe, and smart phone using plethysmogram signal have been emerging for this purpose. All these technologies use irregularity of heartbeat duration as a feature for AF detection. We have investigated a normalization method of heartbeat duration for improved AF detection. AF is an arrhythmia in which heartbeat duration generally becomes irregularly irregular. From a window of heartbeat duration, we estimate the possible rhythm of the majority of heartbeats and normalize duration of all heartbeats in the window based on the rhythm so that we can measure the irregularity of heartbeats for both AF and non-AF rhythms in the same scale. Irregularity is measured by the entropy of distribution of the normalized duration. Then we classify a window of heartbeats as AF or non-AF by thresholding the measured irregularity. The effect of this normalization is evaluated by comparing AF detection performances using duration with the normalization, without normalization, and with other existing normalizations. Sensitivity and specificity of AF detection using normalized heartbeat duration were tested on two landmark databases available online and compared with results of other methods (with/without normalization) by receiver operating characteristic (ROC) curves. ROC analysis showed that the normalization was able to improve the performance of AF detection and it was consistent for a wide range of sensitivity and specificity for use of different thresholds. Detection accuracy was also computed for equal rates of sensitivity and specificity for different methods. Using normalized heartbeat duration, we obtained 96.38% accuracy which is more than 4% improvement compared to AF detection without normalization. The proposed normalization

Operator behaviors observed in following emergency operating procedure under a simulated emergency

International Nuclear Information System (INIS)

Choi, Sun Yeong; Park, Jin Kyun

2012-01-01

A symptom-based procedure with a critical safety function monitoring system has been established to reduce the operator's diagnosis and cognitive burden since the Three-Mile Island (TMI) accident. However, it has been reported that a symptom-based procedure also requires an operator's cognitive efforts to cope with off-normal events. This can be caused by mismatches between a static model, an emergency operating procedure (EOP), and a dynamic process, the nature of an ongoing situation. The purpose of this study is to share the evidence of mismatches that may result in an excessive cognitive burden in conducting EOPs. For this purpose, we analyzed simulated emergency operation records and observed some operator behaviors during the EOP operation: continuous steps, improper description, parameter check at a fixed time, decision by information previously obtained, execution complexity, operation by the operator's knowledge, notes and cautions, and a foldout page. Since observations in this study are comparable to the results of an existing study, it is expected that the operational behaviors observed in this study are generic features of operators who have to cope with a dynamic situation using a static procedure.

Normal-zone detectors for the MFTF-B coils. Revision 1

International Nuclear Information System (INIS)

Owen, E.W.; Shimer, D.W.

1983-01-01

In order to protect a set of inductively coupled superconducting magnets, it is necessary to locate and measure normal zone voltages that are small compared with the mutual and self-induced voltages. The method described in this report uses two sets of voltage measurements to locate and measure one or more normal zones in any number of coupled coils. One set of voltages is the outputs of bridges that balance out the self-induced voltages. The other set of voltages can be the voltages across the coils, although alternatives are possible. The two sets of equations form a single combined set of equations. Each normal zone location or combination of normal zones has a set of these combined equations associated with it. It is demonstrated that the normal zone can be located and the correct set chosen, allowing determination of the size of the normal zone. Only a few operations take place in a working detector: multiplication of a constant, addition, and simple decision-making. In many cases the detector for each coil, although weakly linked to the other detectors, can be considered to be independent. An example of the detector design is given for four coils with realistic parameters. The effect on accuracy of changes in the system parameters is discussed

Mild desalination demo pilot: New normalization approach to effectively evaluate electrodialysis reversal technology

Directory of Open Access Journals (Sweden)

Roel Bisselink

2016-06-01

Full Text Available Key performance indicators for characterization of nanofiltration performance are well developed, similar key performance indicators for electrodialysis reversal are however underdeveloped. Under the E4Water project Dow Benelux BV and Evides Industriewater BV operate a pilot facility to compare both technologies for their application to mildly desalinate a variety of brackish water streams. Normalized pressure drop, normalized current efficiency and normalized membrane resistance proved to be a useful tool to interpret process performance and to initiate a cleaning procedure if required. The availability of these normalized key performance indicators enables optimization and process monitoring and control of electrodialysis reversal independent of the continuously changing conditions of the feed water.

Probabilistic analysis in normal operation of distribution system with distributed generation

DEFF Research Database (Denmark)

Villafafila-Robles, R.; Sumper, A.; Bak-Jensen, B.

2011-01-01

Nowadays, the incorporation of high levels of small-scale non-dispatchable distributed generation is leading to the transition from the traditional 'vertical' power system structure to a 'horizontally-operated' power system, where the distribution networks contain both stochastic generation...... and load. This fact increases the number of stochastic inputs and dependence structures between them need to be considered. The deterministic analysis is not enough to cope with these issues and a new approach is needed. Probabilistic analysis provides a better approach. Moreover, as distribution systems...

Human factors review of electric power dispatch control centers. Volume 4. Operator information needs. Final report

Energy Technology Data Exchange (ETDEWEB)

Miller, R.J.; Najaf-Zadeh, K.; Darlington, H.T.; McNair, H.D.; Seidenstein, S.; Williams, A.R.

1982-10-01

Human factors is a systems-oriented interdisciplinary specialty concerned with the design of systems, equipment, facilities and the operational environment. An important aspect leading to the design requirements is the determination of the information requirements for electric power dispatch control centers. There are significant differences between the system operator's actions during normal and degraded states of power system operation, and power system restoration. This project evaluated the information the operator requires for normal power system and control system operations and investigates the changes of information required by the operator as the power system and/or the control system degrades from a normal operating state. The Phase II study, published in two volumes, defines power system states and control system conditions to which operator information content can be related. This volume presents detailed data concerning operator information needs that identify the needs for and the uses of power system information by a system operator in conditions ranging from normal through degraded operation. The study defines power system states and control system conditions to which operator information content can be related, and it identifies the requisite information as consistent with current industry practice so as to aid control system designers. Training requirements are also included for planning entry-level and follow-on training for operators.

Effect of Machining Velocity in Nanoscale Machining Operations

International Nuclear Information System (INIS)

Islam, Sumaiya; Khondoker, Noman; Ibrahim, Raafat

2015-01-01

The aim of this study is to investigate the generated forces and deformations of single crystal Cu with (100), (110) and (111) crystallographic orientations at nanoscale machining operation. A nanoindenter equipped with nanoscratching attachment was used for machining operations and in-situ observation of a nano scale groove. As a machining parameter, the machining velocity was varied to measure the normal and cutting forces. At a fixed machining velocity, different levels of normal and cutting forces were generated due to different crystallographic orientations of the specimens. Moreover, after machining operation percentage of elastic recovery was measured and it was found that both the elastic and plastic deformations were responsible for producing a nano scale groove within the range of machining velocities from 250-1000 nm/s. (paper)

The Operator's Diagnosis Task under Abnormal Operating Conditions in Industrial Process Plant

DEFF Research Database (Denmark)

Goodstein, L.P.; Pedersen, O.M.; Rasmussen, Jens

1974-01-01

Analysis of serious accidents in connection with the operation of technical installations demonstrate that the diagnosis task which confronts personnel under non-normal plant conditions is a critical one. This report presents a preliminary outline of characteristic traits connected with the task...... of diagnosis for use in discussions of (a) the studies which are necessary in order to formulate the operator's diagnostic procedures and (b) the possibilities which exists for supporting these procedures through appropriate data processing and display in the control system. At the same time, attempts are made...

ACL-RSI and KOOS Measures Predict Normal Knee Function after ACL-SPORTS Training

OpenAIRE

White, Kathleen; Zeni, Joseph; Snyder-Mackler, Lynn

2014-01-01

Objectives: After anterior cruciate ligament reconstruction (ACLR) athletes commonly report increased fear of re-injury and below normal knee function. Implementing a post-operative training protocol (ACL-SPORTS Training) to improve patient perceived knee function, may improve short term outcomes after surgery. Identifying pre-training measures that predict normal knee function after training may allow us to determine who may respond to the treatment intervention. The purpose of this study wa...

Normal zone detectors for a large number of inductively coupled coils

International Nuclear Information System (INIS)

Owen, E.W.; Shimer, D.W.

1983-01-01

In order to protect a set of inductively coupled superconducting magnets, it is necessary to locate and measure normal zone voltages that are small compared with the mutual and self-induced voltages. The method described in this paper uses two sets of voltage measurements to locate and measure one or more normal zones in any number of coupled coils. One set of voltages is the outputs of bridges that balance out the self-induced voltages. The other set of voltages can be the voltages across the coils, although alternatives are possible. The two sets of equations form a single combined set of equations. Each normal zone location or combination of normal zones has a set of these combined equations associated with it. It is demonstrated that the normal zone can be located and the correct set chosen, allowing determination of the size of the normal zone. Only a few operations take place in a working detector: multiplication of a constant, addition, and simple decision-making. In many cases the detector for each coil, although weakly linked to the other detectors, can be considered to be independent

Manifolds with integrable affine shape operator

Directory of Open Access Journals (Sweden)

Daniel A. Joaquín

2005-05-01

Full Text Available This work establishes the conditions for the existence of vector fields with the property that theirs covariant derivative, with respect to the affine normal connection, be the affine shape operatorS in hypersurfaces. Some results are obtained from this property and, in particular, for some kind of affine decomposable hypersurfaces we explicitely get the actual vector fields.

Off-normal performance of EBR-II [Experimental Breeder Reactor] driver fuel

International Nuclear Information System (INIS)

Seidel, B.R.; Batte, G.L.; Lahm, C.E.; Fryer, R.M.; Koenig, J.F.; Hofman, G.L.

1986-09-01

The off-normal performance of EBR-II Mark-II driver fuel has been more than satisfactory as demonstrated by robust reliability under repeated transient overpower and undercooled loss-of-flow tests, by benign run-beyond-cladding-breach behavior, and by forgiving response to fabrication defects including lack of bond. Test results have verified that the metallic driver fuel is very tolerant of off-normal events. This behavior has allowed EBR-II to operate in a combined steady-state and transient mode to provide test capability without limitation from the metallic driver fuel

40 CFR 63.11532 - What definitions apply to this subpart?

Science.gov (United States)

2010-07-01

... exhaust of a fabric filter to detect bag leaks and other upset conditions. A bag leak detection system... operations means the use of electric and electrolytic processes to purify metals or reduce metallic compounds to metals. Fugitive emissions means any pollutant released to the atmosphere that is not discharged...

Evidence for the Existence of a Bone Marrow Blood Barrier for the Passage of Specific Committed Stem Cells in Human and Canine and Their Physical Separation from Lymphocytes and Pluripotent Stem Cells

Science.gov (United States)

1982-11-12

Chest Cold 2. Sastro-intestinal Upset 3. Skin Infections 4. Antibiotic Treatment Within 2 Weeks 5. Pregnancy Within 6 Months 6, Recent Operation...HaematoL 24:367-376, 1973. Thomas, E.D., Buckner, CV., Storb, R.: Aplastic anaemia treated by marrow transplantation. Lancet 1:284-289,1972. Till

[Identification and management of intra-operative suspicious tissues in 20 transsphenoidal surgery cases].

Science.gov (United States)

Liu, Jun-Feng; Ke, Chang-Shu; Chen, Xi; Xu, Yu; Zhang, Hua-Qiu; Chen, Juan; Gan, Chao; Li, Chao-Xi; Lei, Ting

2013-05-01

To determine appropriate protocols for the identification and management of intra operative suspicious tissues during transsphenoidal surgery. Clinical data and pathological reports of 20 patients with intra-operative suspicious tissues during transsphenoidal surgeries were analyzed retrospectively. The methods for discriminating between adenoma and normal pituitary tissues were reviewed. The postoperative pathological reports revealed that adenoma and normal pituitary tissues coexisted in 9 samples, while 5 samples were identified as normal pituitary tissues, 2 as adenoma tissues, and 4 as other tissues. Adenomas were distinguished from normal pituitary tissues on the basis of intra-operative appearance, texture, blood supply and possible existence of boundary. If decisions are difficult to made during surgeries from the appearance of the suspicious tissues, pathological examinations are advised as a guidance for the next steps.

Tritium Systems Test Assembly operator training program

International Nuclear Information System (INIS)

Kerstiens, F.L.

1985-01-01

Proper operator training is needed to help ensure the safe operation of fusion facilities by personnel who are qualified to carry out their assigned responsibilities. Operators control and monitor the Tritium Systems Test Assembly (TSTA) during normal, emergency, and maintenance phases. Their performance is critical both to operational safety, assuring no release of tritium to the atmosphere, and to the successful simulation of the fusion reaction progress. Through proper training we are helping assure that TSTA facility operators perform their assignments in a safe and efficient manner and that the operators maintain high levels of operational proficiency through continuing training, retraining, requalification, and recertification

Intuitionistic Fuzzy Normalized Weighted Bonferroni Mean and Its Application in Multicriteria Decision Making

Directory of Open Access Journals (Sweden)

Wei Zhou

2012-01-01

Full Text Available The Bonferroni mean (BM was introduced by Bonferroni six decades ago but has been a hot research topic recently since its usefulness of the aggregation techniques. The desirable characteristic of the BM is its capability to capture the interrelationship between input arguments. However, the classical BM and GBM ignore the weight vector of aggregated arguments, the general weighted BM (WBM has not the reducibility, and the revised generalized weighted BM (GWBM cannot reflect the interrelationship between the individual criterion and other criteria. To deal with these issues, in this paper, we propose the normalized weighted Bonferroni mean (NWBM and the generalized normalized weighted Bonferroni mean (GNWBM and study their desirable properties, such as reducibility, idempotency, monotonicity, and boundedness. Furthermore, we investigate the NWBM and GNWBM operators under the intuitionistic fuzzy environment which is more common phenomenon in modern life and develop two new intuitionistic fuzzy aggregation operators based on the NWBM and GNWBM, that is, the intuitionistic fuzzy normalized weighted Bonferroni mean (IFNWBM and the generalized intuitionistic fuzzy normalized weighted Bonferroni mean (GIFNWBM. Finally, based on the GIFNWBM, we propose an approach to multicriteria decision making under the intuitionistic fuzzy environment, and a practical example is provided to illustrate our results.

Distributed hierarchical control architecture for integrating smart grid assets during normal and disrupted operations

Science.gov (United States)

Kalsi, Karan; Fuller, Jason C.; Somani, Abhishek; Pratt, Robert G.; Chassin, David P.; Hammerstrom, Donald J.

2017-09-12

Disclosed herein are representative embodiments of methods, apparatus, and systems for facilitating operation and control of a resource distribution system (such as a power grid). Among the disclosed embodiments is a distributed hierarchical control architecture (DHCA) that enables smart grid assets to effectively contribute to grid operations in a controllable manner, while helping to ensure system stability and equitably rewarding their contribution. Embodiments of the disclosed architecture can help unify the dispatch of these resources to provide both market-based and balancing services.

Operational safety analysis of the Olkiluoto disposal site

International Nuclear Information System (INIS)

Rossi, J.; Suolanen, V.

2013-11-01

Radiation doses for workers of the facilities, for inhabitants in the environment and for terrestrial ecosystem possibly caused by the encapsulation and disposal facilities to be built at Olkiluoto during its operation were considered in the study. First the normal encapsulation process is described and then possible incident and accident cases associated to that are identified for this assessment. The study covers both the normal operation of the plant and some hypothetical incidents and accidents. Radioactive releases and radiation doses are evaluated as a consequence of normal operation and some essential incident and accident cases. Release through the ventilation stack is assumed to be filtered (activated when necessary) both in normal operation and in hypothetical abnormal fault and accident cases. In addition the results for unfiltered releases are also presented e.g. for the emergency planning. During about 30 operation years of our four nuclear power plant units there have been found 58 fuel pins failures. Roughly estimating there has been one fuel leakage per year in a facility (includes two units). Based on this and adopting a conservative approach, it is estimated that one fuel pin per year could leak in normal operation during encapsulation process. The release magnitude in incidents and accidents is based on the event chains, which lead to loss of fuel pin tightness followed by a discharge of radionuclides into the handling space and to some degree to the atmosphere through the ventilation stack equipped with redundant filters. The most exposed group of inhabitants is conservatively assumed to live at the distance of 200 meters from the encapsulation and disposal plant and it will receive the largest doses in most dispersion conditions. The dose value to a member of the most exposed group was calculated on the basis of the weather data in such a way that greater dose than obtained here is caused only in 0.5 percent of dispersion conditions. The

The concept of the conservative operating policy

International Nuclear Information System (INIS)

Idita, S.A.

1997-01-01

In the context of the nuclear operating environment, the conservative operating policy is one that promotes a culture of moderation and caution. This policy requires compliance with the intent of the Reactor Operation Licence (ROL) and adherence with the limitations stipulated in the facility Operating Policies and Principles (OPP). While ROL is the document prescribing the laws governing the operation and maintenance the OPP are the statements defining the boundaries within which the facility will be operated. A conservative operating policy, that is well understood by all plant facility personnel provides assurance that plant operation and maintenance will be carried out in compliance with approved operating and maintenance procedures. In an abnormal plant operating situation where OPP's may be challenged, the provision of 'Abnormal Plant Operating Procedures' (APOP's) will stipulate actions designed to return the plant to a condition where normal procedures can be followed i.e. acceptably within OPP limitations. When in a NPP an operating scenario will develop where the the situation is not covered by normal approved operating procedures a conservative operating policy will empower the duty Shift Supervisor (SS) to initiate actions that will move the plant in the 'safe direction'. The paper enumerates the decisions which the SS has to make in order to ensure that the reactor power is correctly controlled, the reactor fuel remains cooled and the radioactivity remains contained. It is stressed that a corporate operating policy will be of little use if its existence is known only by corporate management. To be effective, and to be instrumental in the promotion of a facility safety culture, the conservative operating philosophy must be known about and fully understood by all personnel working at a nuclear facility. It is up to management to 'get the word out' and lead by example. (author)

Normal anatomy and aneurysms of middle cerebral artery

International Nuclear Information System (INIS)

Yeh, Y.S.

1981-01-01

The aim of the present study is to clarify the existing anatomical knowledge and the nomenclature used in describing the normal anatomy of the MCA and its main and cortical branches. The different classifications now available have led to anatomical and terminological confusion and inaccuracy. In this study, it is proposed to make out a new classification and to correlate this with the radiological and operative findings in patients with MCA aneurysms. (orig.)

Computer simulation of WWER - 440 normal and emergency transient operating conditions

International Nuclear Information System (INIS)

Izbeshesku, M.; Rajka, V.; Untaru, S.; Dumitresku, A.; Paneh, M.; Turku, I.

1976-01-01

Results of computer realization of a model for studying transient process in the nuclear system of vapour production at the WWER - 40 peactor nuclear power plant are presented. The first circuit model consists of a number of modules, corresponding to its main parts: for each module derived were the equations describing neutron and thermohydraulic parameters. The second circuit effect is taken into account by heat quantity accepted from a steam generator. The equations are mostly differential with constant coefficients. Coefficient values and initial values of physical quantities are evaluated according to the technical literature. Both manual and automatic operations are modelled [ru

Magnetic structure and microstructure of die-upset hard magnets RE13.75Fe80.25B6 (RE=Nd, Pr): A possible origin of high coercivity

International Nuclear Information System (INIS)

Volkov, V.V.; Zhu, Y.

1999-01-01

In situ transmission electron microscopy magnetizing experiments combined with Lorentz magnetic microscopy in Fresnel endash Foucault modes were used to characterize the magnetic structure of die-upset, high energy-product hard magnets Nd 13.75 Fe 80.25 B 6 and Pr 13.75 Fe 80.25 B 6 . Experimental observations indicate a well-aligned grain structure and quasiperiodic nonaligned open-quotes extended defectclose quotes layers transverse to press direction. The local remanence of the open-quotes defectclose quotes layers is far from saturation when the external field is removed. The layers are enriched with inclusions of approximate composition Nd 7 Fe 3 , generally with a polygonal shape, and are associated with the original ribbon interfaces. They may be responsible for a high coercivity mechanism, since the motion of reverse domains can be impeded by these layers, even when they are nucleated. Thus, a delayed nucleation of reversed domains seems to be a limiting factor for magnetization reversal and coercivity force. Both Lorentz magnetic imaging and high-resolution microscopy highlight the role of magnetocrystalline anisotropy for domain wall-grain boundary interactions and pinning. Local remanence was estimated directly from magnetic moment sensitive Foucault images. copyright 1999 American Institute of Physics

An effort to improve the operators' habits of actions in normal operations and in disturbance situations at TVO NPP in Finland

International Nuclear Information System (INIS)

Karlsson, C.

2004-01-01

Teollisuuden Voima Oy owns and operates two ABB BWR's, each of 850 MW net outputs. A full-scope training simulator was commissioned in March 1990 at the TVO Olkiluoto plant site. This paper discusses the development of a method to evaluate and improve the operators' habits of actions in a task performance at the Teollisuuden Voima Oy full-scope training simulator. The development of the method started as a study in autumn 1992 and the first goal of the study was to analyse the dynamics of operators' decision making in the on-line control of a disturbance situation. The analysis was ready in 1994. The second goal was to develop out of the analysis method a tool that could serve as the instructor's in evaluating the individuals and the crew's simulator performances. It was assumed that such a tool would enhance the efficiency of the simulator training, because with it the instructors could provide more explicit performance feedback for the operators. The next stage was to apply the method to the entire simulator training and create a course, which consists of a theoretical part and practical training on the simulator. That was done in the retraining period in 1998. The future goals are to improve the method so that it will be used in all the simulator training at the Teollisuuden Voima Oy full-scope training simulator (OLKS). (author)

Small Aircraft Transportation System, Higher Volume Operations Concept: Off-Nominal Operations

Science.gov (United States)

Abbott, Terence S.; Consiglio, Maria C.; Baxley, Brian T.; Williams, Daniel M.; Conway, Sheila R.

2005-01-01

This document expands the Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept to include off-nominal conditions. The general philosophy underlying the HVO concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA). During periods of poor weather, a block of airspace would be established around designated non-towered, non-radar airports. Aircraft flying enroute to a SATS airport would be on a standard instrument flight rules flight clearance with Air Traffic Control providing separation services. Within the SCA, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Previous work developed the procedures for normal HVO operations. This document provides details for off-nominal and emergency procedures for situations that could be expected to occur in a future SCA.

Cointegration as a data normalization tool for structural health monitoring applications

Science.gov (United States)

Harvey, Dustin Y.; Todd, Michael D.

2012-04-01

The structural health monitoring literature has shown an abundance of features sensitive to various types of damage in laboratory tests. However, robust feature extraction in the presence of varying operational and environmental conditions has proven to be one of the largest obstacles in the development of practical structural health monitoring systems. Cointegration, a technique adapted from the field of econometrics, has recently been introduced to the SHM field as one solution to the data normalization problem. Response measurements and feature histories often show long-run nonstationarity due to fluctuating temperature, load conditions, or other factors that leads to the occurrence of false positives. Cointegration theory allows nonstationary trends common to two or more time series to be modeled and subsequently removed. Thus, the residual retains sensitivity to damage with dependence on operational and environmental variability removed. This study further explores the use of cointegration as a data normalization tool for structural health monitoring applications.

A New RF System for the CEBAF Normal Conducting Cavities

International Nuclear Information System (INIS)

Curt Hovater; Hai Dong; Alicia Hofler; George Lahti; John Musson; Tomasz Plawski

2004-01-01

The CEBAF Accelerator at Jefferson Lab is a 6 GeV five pass electron accelerator consisting of two superconducting linacs joined by independent magnetic transport arcs. CEBAF also has numerous normal conducting cavities for beam conditioning in the injector and for RF extraction to the experimental halls. The RF systems that presently control these cavities are becoming expensive to maintain, therefore a replacement RF control system is now being developed. For the new RF system, cavity field control is maintained digitally using an FPGA which contains the feedback algorithm. The system incorporates digital down conversion, using quadrature under-sampling at an IF frequency of 70 MHz. The VXI bus-crate was chosen as the operating platform because of its excellent RFI/EMI properties and its compatibility with the EPICS control system. The normal conducting cavities operate at both the 1497 MHz accelerating frequency and the sub-harmonic frequency of 499 MHz. To accommodate this, the ne w design will use different receiver-transmitter daughter cards for each frequency. This paper discusses the development of the new RF system and reports on initial results

Piloted Simulator Evaluation Results of Flight Physics Based Stall Recovery Guidance

Science.gov (United States)

Lombaerts, Thomas; Schuet, Stefan; Stepanyan, Vahram; Kaneshige, John; Hardy, Gordon; Shish, Kimberlee; Robinson, Peter

2018-01-01

In recent studies, it has been observed that loss of control in flight is the most frequent primary cause of accidents. A significant share of accidents in this category can be remedied by upset prevention if possible, and by upset recovery if necessary, in this order of priorities. One of the most important upsets to be recovered from is stall. Recent accidents have shown that a correct stall recovery maneuver remains a big challenge in civil aviation, partly due to a lack of pilot training. A possible strategy to support the flight crew in this demanding context is calculating a recovery guidance signal, and showing this signal in an intuitive way on one of the cockpit displays, for example by means of the flight director. Different methods for calculating the recovery signal, one based on fast model predictive control and another using an energy based approach, have been evaluated in four relevant operational scenarios by experienced commercial as well as test pilots in the Vertical Motion Simulator at NASA Ames Research Center. Evaluation results show that this approach could be able to assist the pilots in executing a correct stall recovery maneuver.

Positive-Operator Valued Measure (POVM Quantization

Directory of Open Access Journals (Sweden)

Jean Pierre Gazeau

2014-12-01

Full Text Available We present a general formalism for giving a measure space paired with a separable Hilbert space a quantum version based on a normalized positive operator-valued measure. The latter are built from families of density operators labeled by points of the measure space. We especially focus on various probabilistic aspects of these constructions. Simple ormore elaborate examples illustrate the procedure: circle, two-sphere, plane and half-plane. Links with Positive-Operator Valued Measure (POVM quantum measurement and quantum statistical inference are sketched.

U.S. Climate Change Technology Program: Strategic Plan

Science.gov (United States)

2006-09-01

page 185 9-2 Laser-Assisted Welding Imaging System...for automotive and stationary applications. Additional research is underway to use hydrogen in auxiliary power units in heavy vehicles to supplant...operations, routine maintenance, and system upsets are the primary contributors. Emissions vary greatly from facility to facility and are largely a

Statistical validation of normal tissue complication probability models.

Science.gov (United States)

Xu, Cheng-Jian; van der Schaaf, Arjen; Van't Veld, Aart A; Langendijk, Johannes A; Schilstra, Cornelis

2012-09-01

To investigate the applicability and value of double cross-validation and permutation tests as established statistical approaches in the validation of normal tissue complication probability (NTCP) models. A penalized regression method, LASSO (least absolute shrinkage and selection operator), was used to build NTCP models for xerostomia after radiation therapy treatment of head-and-neck cancer. Model assessment was based on the likelihood function and the area under the receiver operating characteristic curve. Repeated double cross-validation showed the uncertainty and instability of the NTCP models and indicated that the statistical significance of model performance can be obtained by permutation testing. Repeated double cross-validation and permutation tests are recommended to validate NTCP models before clinical use. Copyright © 2012 Elsevier Inc. All rights reserved.

Statistical Validation of Normal Tissue Complication Probability Models

Energy Technology Data Exchange (ETDEWEB)

Xu Chengjian, E-mail: c.j.xu@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Schaaf, Arjen van der; Veld, Aart A. van' t; Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Schilstra, Cornelis [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Radiotherapy Institute Friesland, Leeuwarden (Netherlands)

2012-09-01

Purpose: To investigate the applicability and value of double cross-validation and permutation tests as established statistical approaches in the validation of normal tissue complication probability (NTCP) models. Methods and Materials: A penalized regression method, LASSO (least absolute shrinkage and selection operator), was used to build NTCP models for xerostomia after radiation therapy treatment of head-and-neck cancer. Model assessment was based on the likelihood function and the area under the receiver operating characteristic curve. Results: Repeated double cross-validation showed the uncertainty and instability of the NTCP models and indicated that the statistical significance of model performance can be obtained by permutation testing. Conclusion: Repeated double cross-validation and permutation tests are recommended to validate NTCP models before clinical use.

Diagonal ordering operation technique applied to Morse oscillator

Energy Technology Data Exchange (ETDEWEB)

Popov, Dušan, E-mail: dusan_popov@yahoo.co.uk [Politehnica University Timisoara, Department of Physical Foundations of Engineering, Bd. V. Parvan No. 2, 300223 Timisoara (Romania); Dong, Shi-Hai [CIDETEC, Instituto Politecnico Nacional, Unidad Profesional Adolfo Lopez Mateos, Mexico D.F. 07700 (Mexico); Popov, Miodrag [Politehnica University Timisoara, Department of Steel Structures and Building Mechanics, Traian Lalescu Street, No. 2/A, 300223 Timisoara (Romania)

2015-11-15

We generalize the technique called as the integration within a normally ordered product (IWOP) of operators referring to the creation and annihilation operators of the harmonic oscillator coherent states to a new operatorial approach, i.e. the diagonal ordering operation technique (DOOT) about the calculations connected with the normally ordered product of generalized creation and annihilation operators that generate the generalized hypergeometric coherent states. We apply this technique to the coherent states of the Morse oscillator including the mixed (thermal) state case and get the well-known results achieved by other methods in the corresponding coherent state representation. Also, in the last section we construct the coherent states for the continuous dynamics of the Morse oscillator by using two new methods: the discrete–continuous limit, respectively by solving a finite difference equation. Finally, we construct the coherent states corresponding to the whole Morse spectrum (discrete plus continuous) and demonstrate their properties according the Klauder’s prescriptions.

Participation in testing and start up operations

International Nuclear Information System (INIS)

Prasad, Y.S.R.

1977-01-01

Testing and start up operations of a nuclear power plant require careful planning. A detailed program of tests and the responsibility of implementing them is discussed. Requirement of documentation covering the tests and operating procedures is explained. The performance of the system during normal and abnomal operating conditions is analysed and required are modifications carried out. Various phases of commissioning and their significance are explained. Preparation of maintenance documentation and training of operating and maintenance staff during this period are discussed. Necessity of close liaison between the regulatory body and the operating organization is explained. (orig.) [de

Computed tomography of the brain in the diagnosis of and prognosis in normal pressure hydrocephalus

International Nuclear Information System (INIS)

Wikkelsoe, C.; Blomstrand, C.; Andersson, H.; Matousek, M.; Svendsen, P.

1989-01-01

Thirty-eight patients with normal pressure hydrocephalus were examined by CT before and after a ventriculo-peritoneal shunt operation. Evans ratio, periventricular hypodensity and width of hemispheric sulci, sylvian fissures, cella media, temporal horns and third and fourth ventricle were examined. Twenty-eight patients improved after the operation while 10 were unchanged (non responders). Those patients who improved had more often enlarged third ventricle, enlarged temporal horns and normal sylvian fissures than those who did not improve. No single CT parameter or combination of CT parameters alone could identify responders and non-responders. The ventriculo-peritoneal shunt operation reduced ventricular size (Evans ratio, cella media width), abolished periventricular hypodensity and reduced width of the temporal horns and third ventricle in both responders and non-responders. Reduction of the width of the third ventricle correlated to clinical improvement. (orig.)

MISTRAL V1.1.1: assessing doses from atmospheric releases in normal and off-normal conditions

International Nuclear Information System (INIS)

David Kerouanton; Patrick Devin; Malvina Rennesson

2006-01-01

Protecting the environment and the public from radioactive and chemical hazards has always been a top priority for all companies operating in the nuclear domain. In this scope, SGN provides all the services the nuclear industry needs in environmental studies especially in relation to the impact assessment in normal operating conditions and risk assessment in off-normal conditions. In order to quantify dose impact on members of the public due to atmospheric releases, COGEMA and SGN developed MISTRAL V1.1.1 code. Dose impact depends strongly on dispersion of radionuclides in atmosphere. The main parameters involved in dispersion characterization are wind velocity and direction, rain, diffusion conditions, coordinates of the point of observation and stack elevation. MISTRAL code implements DOURY and PASQUILL Gaussian plume models which are widely used in the scientific community. These models, applicable for distances of transfer ranging from 100 m up to 30 km, are used to calculate atmospheric concentration and deposit at different distances from the point of release. MISTRAL allows the use of different dose regulations or dose coefficient databases such as: - ICRP30 and ICPR71 for internal doses (inhalation, ingestion) - Despres/Kocher database or US-EPA Federal Guidance no.12 (ICPR72 for noble gases) for external exposure (from plume or ground). The initial instant of the release can be considered as the origin of time or a date format can be specified (could be useful in a crisis context). While the context is specified, the user define the meteorological conditions of the release. In normal operating mode (routine releases), the user gives the annual meteorological scheme. The data can be recorded in the MISTRAL meteorological database. In off-normal conditions mode, MISTRAL V1.1 allows the use of successive release stages for which the user gives the duration, the meteorological conditions, that is to say stability class, wind speed and direction and rainfall

Modeling Operating Modes for the Monju Nuclear Power Plant

DEFF Research Database (Denmark)

Lind, Morten; Yoshikawa, Hidekazu; Jørgensen, Sten Bay

2012-01-01

The specification of supervision and control tasks in complex processes requires definition of plant states on various levels of abstraction related to plant operation in start-up, normal operation and shut-down. Modes of plant operation are often specified in relation to a plant decomposition in...... for the Japanese fast breeder reactor plant MONJU....