Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “CEA”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Enhanced micro-pocket fission detector for high temperature reactor evaluations - 259

A collaboration between the Idaho National Laboratory (INL), the Kansas State University (KSU), and the French Atomic Energy Agency, Commissariat a l'energie Atomique et aux Energies Alternatives, (CEA), has been initiated by the Nuclear Energy Enabling Technologies (NEET) Advanced Sensors and Instrumentation (ASI) program for developing and testing High Temperature Micro-Pocket Fission Detectors (HT MPFD), which are compact fission chambers capable of simultaneously measuring thermal neutron flux, fast neutron flux and temperature within a single package for temperatures up to 800 deg. C. The MPFD technology utilizes small, multi-purpose, robust, in-core fission chambers and can be configured with a thermocouple. The small size, variable sensitivity, and increased accuracy of the MPFD technology represent a revolutionary improvement over current methods used to support irradiations in US Material Test Reactors (MTRs). Previous research conducted through NEET ASI has shown that the MPFD technology could be made robust and was successfully tested in a reactor core. In addition, the accomplishments of this project have attracted independent funding from other Department of Energy Office of Nuclear Energy (DOE-NE) programs for MTR irradiations of the MPFD technology. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

New Features of TRIPOLI-4{sup R} Version 10

TRIPOLI-4{sup R} is a three-dimensional and continuous-energy Monte-Carlo transport code developed by the 'Service d'Etudes des Reacteurs et de Mathematiques Appliquees' (SERMA), at the CEA Paris-Saclay Center. It is devoted to shielding, reactor physics, criticality safety and nuclear instrumentation. TRIPOLI-4{sup R} has been developed from the mid 1990's in C++. A new version of the code is typically released every two years. In this paper, we present the new features of TRIPOLI- 4{sup R} version 10, to be soon released to NEA and RSICC.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

2013 Caliban and Prospero experiments for the study of the behavior of radiation protection instrumentations in case of a criticality accident - 14346

Experiments using the CALIBAN and PROSPERO reactors were performed in 2013 in the framework of a collaboration between IRSN and CEA. The objective was to provide data about the possibility to use information given by radiation protection instrumentations (RPI) in the case of a criticality accident. In that purpose, the behavior of RPI was studied for various kinetics of the reactors which simulated different starts of a criticality accident. The article presents the safety issues associated with these experiments, i.e. the possible use of information given by the RPI for the emergency response of a criticality accident (detection of the accident, triage of the personnel, follow-up of the accident and reentry). Then, one paragraph is dedicated to the presentation of the tested material. In addition, the CALIBAN and PROSPERO reactors are briefly described, followed by the performed experiments. The RPI are neither designed nor dedicated to be used in case of a criticality accident. However, the preliminary conclusion of the experiments performed in 2013 is that the tested RPI have a correct behavior for slow kinetic experiments performed with the PROSPERO reactor, but might give less reliable and accurate information for pulse experiments performed with the CALIBAN reactor. In the last case, they can nevertheless provide information that can be helpful for the emergency response and the limitation of the consequences of the criticality accident. However, if the RPI are included in the emergency response of a criticality accident (detection, triage, follow-up, reentry), emergency procedures should be adapted. Other experiments might be performed in order to confirm results and to extend the number of tested materials, in particular portable survey meters or contamination area monitors. (authors)

42 ENGINEERING↗
DOE OSTI2015

Inter-code comparison of TRIPOLI{sup R} And MVP on the MCNP criticality validation suite - 14421

This paper presents a joint work conducted at CEA Saclay and JAEA Tokai aimed at comparing the Monte Carlo codes TRIPOLI-4{sup R} and MVP on a selection of ICSBEP benchmarks. Our goal is to establish a common set of Monte Carlo input decks, as a basis for rigorous inter-code comparison in criticality-safety. As a reference, we will use the MCNP Criticality Validation Suite: other Monte Carlo developers might easily join this effort in the future. For the purpose of inter-code comparison, the TRIPOLI-4{sup R} and MVP input decks have been exactly translated from those of MCNP, without any further assumptions. Both TRIPOLI-4{sup R} and MVP have been run with the same ENDF/B-VII.0 evaluated nuclear data and, as far as possible, the same simulation options as in the original LANL work (same initial source, same number of active and discarded cycles and neutrons per cycle). (authors)

42 ENGINEERING↗
DOE OSTI2015

CRISTAL V2.0: A New-generation criticality package - 14597

A new release of the CRISTAL French criticality calculation package, named CRISTAL V2.0, has been developed and intensively validated by IRSN and CEA, in collaboration with AREVA. This package was designed to cover the needs of criticality practitioners in the fields of nuclear fuel cycle facilities and transportation of fissile materials. Based on an optimized modular architecture in an updated software development environment, the design of CRISTAL package V2.0 integrates new generation of cross section libraries, new calculation schemes consistent with new applications, and up-to-date calculation codes capabilities. Four calculation routes are currently available allowing multi-group and continuous energy calculations. The validation database is composed of more than 3000 critical experiments, in order to cover a wide range of configurations. The CRISTAL V2.0 package also comprises customer services covering a range of areas of activity like documentation, hotline, maintenance and training courses. A wide promotion and an increased recognition referred both nationally and internationally are foreseen, including the provision of the CRISTAL V2.0 package to the OECD / NEA Data Bank. (authors)

42 ENGINEERING↗
DOE OSTI2022

Prognostic importance of the preoperative New‐Naples prognostic score for patients with gastric cancer

Abstract Background The wide applicability of the Naples prognostic score (NPS) is still worthy of further study in gastric cancer (GC). This study aimed to construct a New‐NPS based on the differences in immunity and nutrition in patients with upper and lower gastrointestinal tumors to help obtain an individualized prediction of prognosis. Methods This study retrospectively analyzed patients who underwent radical gastrectomy from April 2014 to September 2016. The cutoff values of the preoperative neutrophil‐to‐lymphocyte ratio (NLR), lymphocyte‐to‐monocyte ratio (LMR), serum albumin (Alb), and total cholesterol (TC) were calculated by ROC curve analysis. ROC and t‐ROC were used to evaluate the accuracy of the prognostic markers. The Kaplan–Meier method and log‐rank test were used to analyze the overall survival probability. Univariate and multivariate analyses based on Cox risk regression were used to show the independent predictors. The nomogram was made by R studio. The predictive accuracy of nomogram was assessed using a calibration plot, concordance index (C‐index), and decision curve. Results A total of 737 patients were included in training cohort, 411 patients were included in validation cohort. ROC showed that the New‐NPS was more suitable for predicting the prognosis of GC patients. NPS = 2 indicated a poor prognosis. Multivariate analysis showed that CEA ( P = 0.026), Borrmann type ( P = 0.001), pTNM ( P < 0.001), New‐NPS ( P < 0.001), and nerve infiltration ( P = 0.035) were independent risk factors for prognosis. Conclusion The New‐NPS based on the cutoff values of NLR, LMR, Alb, and TC is not only suitable for predicting prognosis but can also be combined with clinicopathological characteristics to construct a nomogram model for GC patients.

Wang, Hao↗
DOE OSTI2012

Matched-Pair Comparison of Radioembolization Plus Best Supportive Care Versus Best Supportive Care Alone for Chemotherapy Refractory Liver-Dominant Colorectal Metastases

Purpose: This study was designed to evaluate overall survival after radioembolization or best supportive care (BSC) in patients with chemotherapy-refractory liver-dominant metastatic colorectal cancer (mCRC). Methods: This was a matched-pair comparison of patients who received radioembolization plus BSC or BSC alone for extensive liver disease. Twenty-nine patients who received radioembolization were retrospectively matched with a contemporary cohort of >500 patients who received BSC from 3 centers in Germany. Using clinical databases, patients were initially matched for prior treatments and tumor burden and then 29 patients were consecutively identified with two or more of four matching criteria: synchronous/metachronous metastases, tumor burden, increased ALP, and/or CEA >200 U/ml. Survival was calculated from date of progression before radioembolization or BSC by using Kaplan-Meier analysis. Results: Of 29 patients in each study arm, 16 pairs (55.2%) matched for all four criteria, and 11 pairs (37.9%) matched three criteria. Patients in both groups had a similar performance status (Karnofsky index, median 80% [range, 60-100%]). Compared with BSC alone, radioembolization prolonged survival (median, 8.3 vs. 3.5 months; P < 0.001) with a hazard ratio of 0.3 (95% confidence interval, 0.16-0.55; P < 0.001) in a multivariate Cox proportional hazard model. Treatment-related adverse events following radioembolization included: grade 1-2 fatigue (n = 20, 69%), grade 1 abdominal pain/nausea (n = 14, 48.3%), and grade 2 gastrointestinal ulceration (n = 3, 10.3%). Three cases of grade 3 radiation-induced liver disease were symptomatically managed. Conclusions: Radioembolization offers a promising addition to BSC in treatment-refractory patients for whom there are limited options. Survival was prolonged and adverse events were generally mild-to-moderate in nature and manageable.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Epidural Analgesia Versus Patient-Controlled Analgesia for Pain Relief in Uterine Artery Embolization for Uterine Fibroids: A Decision Analysis

Purpose: This study was designed to compare the costs and effects of epidural analgesia (EDA) to those of patient-controlled intravenous analgesia (PCA) for postintervention pain relief in women having uterine artery embolization (UAE) for systematic uterine fibroids. Methods: Cost-effectiveness analysis (CEA) based on data from the literature by constructing a decision tree to model the clinical pathways for estimating the effects and costs of treatment with EDA and PCA. Literature on EDA for pain-relief after UAE was missing, and therefore, data on EDA for abdominal surgery were used. Outcome measures were compared costs to reduce one point in visual analogue score (VAS) or numeric rating scale (NRS) for pain 6 and 24 h after UAE and risk for complications. Results: Six hours after the intervention, the VAS was 3.56 when using PCA and 2.0 when using EDA. The costs for pain relief in women undergoing UAE with PCA and EDA were Euro-Sign 191 and Euro-Sign 355, respectively. The costs for EDA to reduce the VAS score 6 h after the intervention with one point compared with PCA were Euro-Sign 105 and Euro-Sign 179 after 24 h. The risk of having a complication was 2.45 times higher when using EDA. Conclusions: The results of this indirect comparison of EDA for abdominal surgery with PCA for UAE show that EDA would provide superior analgesia for post UAE pain at 6 and 24 h but with higher costs and an increased risk of complications.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2020

Neutron heating assessment in Minerve reactor by using alanine/ESR dosimetry

In the framework of the ICERR (International Center based on Research Reactors) project, the effect of neutron/gamma irradiation on material and dosimeters has been studied. In this work, we explore the alanine dose-response in the core of the MINERVE research reactor at the CEA Cadarache and we investigate the neutron heating effects in order to evaluate alanine neutron sensitivity. The measured dose of the alanine detector in the mixed gamma-neutron field was estimated by electron spin resonance spectrometry (ESR) with reference to an absorbed dose in water from a 60 Co gamma-ray beam. The experimental sources of uncertainties were reduced by using the optimum conditions of charged-particle equilibrium (CPE), obtained by introducing alanine dosimeters into the aluminum pillbox. Cavity correction factors and dose components were evaluated by the Monte Carlo code MCNP. The calculation showed an underestimated neutron dose with a (C/E) value of about 0.993 +/- 10.83%(k = 1). Results indicate that the fast neutron dose, mainly due to elastic neutron scattering on hydrogen nuclei, represents about 70% of the total dose, while the gamma dose was found to be around 45% of the neutron dose. Additionally, the neutron relative efficiency (REn) to 60 Co gamma-radiation was estimated to be 0.544 +/- 8%(k = 1).

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2014

Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter is activated by E2F only in cancer cells and therefore may be more cancer cell-specific than E2F1 promoter to drive gene expression. We show here that the ARF promoter has lower activity in normal growing fibroblasts and shows higher cancer cell-specificity compared to the E2F1 promoter. We also demonstrate that adenovirus expressing HSV-TK under the control of the ARF promoter shows lower cytotoxicity than that of the E2F1 promoter, in normal growing fibroblasts but has equivalent cytotoxicity in cancer cell lines. These results suggest that the ARF promoter, which is specifically activated by deregulated E2F activity, is an excellent candidate to drive therapeutic cytotoxic gene expression, specifically in cancer cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

Design and analysis of actively-cooled, edge-transport diagnostic for long-pulsed operation in WEST

Next step fusion devices that will operate in steady-state will require complex plasma-facing components (PFCs) that can survive the harsh environment over long timescales not common in current devices. This will require robust plasma facing surfaces that are integrated with active cooling systems. In a collaboration between CEA and ORNL, a plasma-interacting diagnostic is being designed for the W Environment in Steady-state Tokamak (WEST) in Cadarache, France which requires plasma-facing protection like those needed for steady-state PFCs. This integrated diagnostic studies edge transport and impurity migration within WEST, and is planned to include imbedded temperature Langmuir probe sensors, as well as removeable sample slots for ex-situ surface analysis of plasma-material interactions. The entire assembly is expected to move into the plasma edge for periods up to 1000 s having an energy removeable capability of ∼6 kW and seeing a peak heat flux of more than 7 MW/m2. The assembly compliments WEST high fluence campaigns that plan for multiple 1000 s pulses. Within these specifications, the assembly will require a refractory metal plasma facing surface and integral cooling in order to function within the limited space allotted for such diagnostics. Because of the limited space and linear actuator needs, additive manufacturing of the high heat flux working end of the assembly is being considered which could allow for precision cooling-channels and lighter weight designs. Conceptual design along with simulation and analysis results will be presented for this complex diagnostic with novel PFCs.

Lumsdaine, Arnold↗
DOE OSTI2014

Risk Factors for Brain Metastases in Locally Advanced Non-Small Cell Lung Cancer With Definitive Chest Radiation

Purpose: We intended to identify risk factors that affect brain metastases (BM) in patients with locally advanced non-small cell lung cancer (LA-NSCLC) receiving definitive radiation therapy, which may guide the choice of selective prevention strategies. Methods and Materials: The characteristics of 346 patients with stage III NSCLC treated with thoracic radiation therapy from January 2008 to December 2010 in our institution were retrospectively reviewed. BM rates were analyzed by the Kaplan-Meier method. Multivariate Cox regression analysis was performed to determine independent risk factors for BM. Results: The median follow-up time was 48.3 months in surviving patients. A total of 74 patients (21.4%) experienced BM at the time of analysis, and for 40 (11.7%) of them, the brain was the first site of failure. The 1-year and 3-year brain metastasis rates were 15% and 28.1%, respectively. In univariate analysis, female sex, age ≤60 years, non-squamous cell carcinoma, T3-4, N3, >3 areas of lymph node metastasis, high lactate dehydrogenase and serum levels of tumor markers (CEA, NSE, CA125) before treatment were significantly associated with BM (P<.05). In multivariate analysis, age ≤60 years (P=.004, hazard ratio [HR] = 0.491), non-squamous cell carcinoma (P=.000, HR=3.726), NSE >18 ng/mL (P=.008, HR=1.968) and CA125 ≥ 35 U/mL (P=.002, HR=2.129) were independent risk factors for BM. For patients with 0, 1, 2, and 3 to 4 risk factors, the 3-year BM rates were 7.3%, 18.9%, 35.8%, and 70.3%, respectively (P<.001). Conclusions: Age ≤60 years, non-squamous cell carcinoma, serum NSE >18 ng/mL, and CA125 ≥ 35 U/mL were independent risk factors for brain metastasis. The possibilities of selectively using prophylactic cranial irradiation in higher-risk patients with LA-NSCLC should be further explored in the future.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Swelling of U(Mo)–Al(Si) dispersion fuel under irradiation – Non-destructive analyses of the LEONIDAS E-FUTURE plates

In the framework of the elimination of High-Enriched Uranium (HEU) from the civil circuit, the search for an appropriate fuel to replace the high-enriched research reactor fuel in those reactors that currently still require it for their operation has led to the development of a U–7 wt.%Mo alloy based dispersion fuel with an Al–Si matrix. The European LEONIDAS program, joining SCK-CEN, ILL, CEA and AREVA-CERCA, is aimed at the qualification of such a fuel for the use in high power conditions. The first experiment of the program, designated E-FUTURE, was performed to select the appropriate matrix Si concentration and fuel plate post-production heat treatment parameters for further qualification. It consisted of the irradiation of four distinct (4% and 6% Si, 3 different heat treatments) full size, flat fuel plates in the BR2 reactor. The irradiation conditions were relatively severe: 470 W/cm2 peak BOL power, with an approximate 70% 235U peak burnup.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2020

Evaluation of the Prompt Fission Gamma Properties for Neutron Induced Fission of 235,238 U and 239 Pu

Herein we present details of the prompt fission gamma property evaluations included in the released ENDF/B-VIII.0 files. The average prompt gamma multiplicity, the average prompt gamma spectrum, the average total prompt gamma energy released and the prompt gamma multiplicity distributions, included in the ENDF/B-VIII.0 files, are presented for 235 U(n,f), 238 U(n,f), and 239 Pu(n,f) reactions, as a function of incident neutron energy up to 30 MeV. The evaluation is based on available experimental data and model calculations. Notable data include recent measurements by experimental groups at Los Alamos and Lawrence Livermore National Laboratories, at Geel and Budapest, at CEA labs, as well as seminal historical gamma production measurements by Drake at Los Alamos.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

New Nonreactive Force Field for Accurate Molecular Dynamics Simulations of TATB at Extreme Conditions

Insensitive high explosives based on TATB (1,3,5-triamino-2,4,6-trinitrobenzene) are needed in applications when safety is of paramount importance, but the basic material properties that give rise to its insensitivity are not fully understood. Molecular dynamics modeling using empirical force fields (FFs) has been the main route to characterize many complicated dynamical properties of TATB single crystal, but these FFs have not been comprehensively tested at extreme conditions typical of detonation. We collect a benchmark data set of (quasi)static TATB physical properties as determined by experiments and electronic structure calculations and apply this data set to validate four existing TATB FFs along with a new TATB FF that we develop here and denote as the CEA-LLNL-Missouri (CLM) FF. Benchmark data include vibrational spectra, the TATB crystal temperature–pressure–volume equation of state and lattice parameters, properties of TATB crystal polymorphs and transitions to the gaseous and liquid states, dimer energy landscapes, the pressure-dependent elastic tensor, and the energy landscape for inelastic deformation via sliding of TATB crystal layers. As a general assessment, we find that the two existing nonreactive FFs are more accurate in describing TATB’s physical properties compared to the two variants of the ReaxFF reactive FF considered. The new CLM FF is found to consistently yield similar or better agreement with experiments and electronic structure theory than any of the existing FF models, and it presents a distinct improvement in accurately modeling TATB elasticity and equation of state. So this work is expected to help improve the accuracy of FF-based modeling of complicated dynamic responses that ultimately govern the safety and performance characteristics of this material.

36 MATERIALS SCIENCE↗
DOE OSTI2021

The Princess Project: From Differential to Integral Experiments

Following the shutdown of the CEA Valduc experimental facilities, where, for more than 50 years, IRSN used to perform experiments related to criticality safety, IRSN initiated a new project named PRINCESS (PRoject for IRSN Neutron physics and Criticality Experimental data Supporting Safety). The objective is to continue collecting experimental data necessary for the IRSN missions in nuclear safety. For this purpose, collaborations with various national and international laboratories have been established. The PRINCESS project covers various nuclear physics fields from nuclear data to criticality-safety and reactor physics providing information to both differential and integral data improvements.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2011

Status of the 1 MeV Accelerator Design for ITER NBI

The beam source of neutral beam heating/current drive system for ITER is needed to accelerate the negative ion beam of 40A with D{sup -} at 1 MeV for 3600 sec. In order to realize the beam source, design and R and D works are being developed in many institutions under the coordination of ITER organization. The development of the key issues of the ion source including source plasma uniformity, suppression of co-extracted electron in D beam operation and also after the long beam duration time of over a few 100 sec, is progressed mainly in IPP with the facilities of BATMAN, MANITU and RADI. In the near future, ELISE, that will be tested the half size of the ITER ion source, will start the operation in 2011, and then SPIDER, which demonstrates negative ion production and extraction with the same size and same structure as the ITER ion source, will start the operation in 2014 as part of the NBTF. The development of the accelerator is progressed mainly in JAEA with the MeV test facility, and also the computer simulation of beam optics also developed in JAEA, CEA and RFX. The full ITER heating and current drive beam performance will be demonstrated in MITICA, which will start operation in 2016 as part of the NBTF.

43 PARTICLE ACCELERATORS↗