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1

Clementine mission  

NASA Astrophysics Data System (ADS)

The U.S. Department of Defense (DoD) and the National Aeronautics and Space Administration (NASA) started a cooperative program in 1992 to flight qualify recently developed lightweight technologies in a radiation stressed environment. The spacecraft, referred to as Clementine, was designed, built, and launched in less than a two year period. The spacecraft was launched into a high inclination orbit from Vandenburg Air Force Base in California on a Titan IIG launch vehicle in January 1994. The spacecraft was injected into a 420 by 3000 km orbit around the Moon and remained there for over two months. Unfortunately, after successfully completing the Lunar phase of the mission, a software malfunction prevented the accomplishment of the near-Earth asteroid (NEA) phase. Some of the technologies incorporated in the Clementine spacecraft include: a 370 gram, 7 watt star tracker camera; a 500 gram, 6 watt, UV/Vis camera; a 1600 gram, 30 watt Indium Antimonide focal plane array NIR camera; a 1650 gram, 30 watt, Mercury Cadmium Telluride LWIR camera; a LIDAR camera which consists of a Nd:YAG diode pumped laser for ranging and an intensified photocathode charge-coupled detector for imaging. The scientific results of the mission will be first analyzed by a NASA selected team, and then will be available to the entire community.

Rustan, Pedro L.

1995-01-01

2

The Clementine satellite  

SciTech Connect

The first US satellite to the Moon in more than two decades was launched from Vandenberg Air Force Base (Santa Barbara County), California, on January 25, 1994. The satellite was named Clementine because it carried only enough fuel to complete its mission before it was [open quotes]lost and gone forever.[close quotes] The Clementine satellite tested 23 advanced technologies during its mission for the Ballistic Missile Defense Organization. In fulfilling its scientific goals, Clementine provided a wealth of information relevant to the mineralogy of the lunar surface. Using six on-board cameras designed and built at the Laboratory, Clementine mapped the entire surface of the Moon at resolutions never before attained. Clementine also provided range data that will be used to construct a relief map of the lunar surface.

Not Available

1994-06-01

3

The Clementine Bistatic Radar Experiment  

Microsoft Academic Search

During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, beta, for selected lunar areas. Observations of the lunar south pole yield a same-sense polarization enhancement around beta = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar

S. Nozette; C. L. Lichtenberg; P. Spudis; R. Bonner; W. Ort; E. Malaret; M. Robinson; E. M. Shoemaker

1996-01-01

4

Clementine RRELAX SRAM particle spectrometer  

SciTech Connect

The Clementine RRELAX radiation monitor chip consists of a p-FET total dose monitor and a 4-kbit SRAM particle spectrometer. Eight of these chips were included in the RRELAX and used to detect the passage of the Clementine (S/C) and the innerstage adapter (ISA) through the earth's radiation belts and the 21-Feb 1994 solar flare. This is the first space flight for this 1.2-[mu]m rad-soft custom CMOS radiation monitor. This paper emphasizes results from the SRAM particle detector which showed that it (a) has a detection range of five orders of magnitude relative to the 21-Feb solar flare, (b) is not affected by electrons, and (c) detected microflares occurring with a 26.5-day period.

Buehler, M.G.; Soli, G.A.; Blaes, B.R.; Ratliff, J.M.; Garrett, H.B. (California Inst. of Technology, Pasadena, CA (United States). Jet Propulsion Lab.)

1994-12-01

5

Efficient Material Mapping Using Clementine Multispectral Data  

NASA Astrophysics Data System (ADS)

Clementine UVVIS and NIR images have been used to interpret mineralogy of the lunar surface. We have applied two algorithms to the mosaic of the Aristarchus plateau produced by which efficiently map the regional mineralogy. This technique may be applied to the entirety of Clementine data now available.

Steutel, D.; Lucey, P. G.; Winter, M. E.; Le Mouelic, S.

2002-01-01

6

The Clementine bistatic radar experiment.  

PubMed

During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, beta, for selected lunar areas. Observations of the lunar south pole yield a same-sense polarization enhancement around beta = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no such enhancement. A probable explanation for these differences is the presence of low-loss volume scatterers, such as water ice, in the permanently shadowed region at the south pole. PMID:8929403

Nozette, S; Lichtenberg, C L; Spudis, P; Bonner, R; Ort, W; Malaret, E; Robinson, M; Shoemaker, E M

1996-11-29

7

Clementine Mosaics Warped to ULCN2005 Network  

Microsoft Academic Search

Over the past year we have released updated Clementine mosaics and the USGS lunar airbrushed shaded relief global map which have been warped to the ULCN 2005 control network. This abstract describes the methods and related errors.

T. M. Hare; B. A. Archinal; T. L. Becker; L. R. Gaddis; E. M. Lee; B. L. Redding; M. R. Rosiek

2008-01-01

8

The Clementine longwave infrared camera  

SciTech Connect

The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. The longwave-infrared (LWIR) camera supplemented the UV/Visible and near-infrared mapping cameras providing limited strip coverage of the moon, giving insight to the thermal properties of the soils. This camera provided {approximately}100 m spatial resolution at 400 km periselene, and a 7 km across-track swath. This 2.1 kg camera using a 128 x 128 Mercury-Cadmium-Telluride (MCT) FPA viewed thermal emission of the lunar surface and lunar horizon in the 8.0 to 9.5 {micro}m wavelength region. A description of this light-weight, low power LWIR camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights.

Priest, R.E.; Lewis, I.T.; Sewall, N.R.; Park, H.S.; Shannon, M.J.; Ledebuhr, A.G.; Pleasance, L.D. [Lawrence Livermore National Lab., CA (United States); Massie, M.A. [Pacific Advanced Technology, Solvang, CA (United States); Metschuleit, K. [Amber/A Raytheon Co., Goleta, CA (United States)

1995-04-01

9

7 CFR 319.56-38 - Clementines, mandarins, and tangerines from Chile.  

Code of Federal Regulations, 2010 CFR

...Clementines, mandarins, and tangerines from Chile. 319.56-38 Section 319.56-38...Clementines, mandarins, and tangerines from Chile. Clementines (Citrus reticulata ...be imported into the United States from Chile only under the following...

2009-01-01

10

The Clementine Mission: Past, Present, and Future  

NASA Astrophysics Data System (ADS)

During the past decade the Department of Defense, and the Ballistic Missile Defense Organization, BMDO (formally the Strategic Defense Initiative Organization, SDIO) of the US Department of Defense (DoD) have invested heavily in space technology, focused on the development of lighter more cost effective components and systems. With the end of the Cold War many of these technologies can be made available to the civilian community. To further these efforts in dual-use application, BMDO and NASA have collaborated on the Clementine mission. The Clementine spacecraft was launched on 25 January 1994 as a test of many of the most advanced lightweight technologies ever developed by the DoD. Clementine is currently in lunar orbit performing the lunar mapping phase of its mission. The mission has been integrated by a Naval Research Laboratory government/industry team in less than two years. The spacecraft itself has a dry weight of about 227 kg made possible by using very lightweight components. The sensor suite, provided by a Lawrence Livermore National Laboratory/industry team consists of two star tracker cameras, an ultraviolet-visible camera, a short wave infrared camera, a long wave infrared camera, and LIDAR, weighs less than 8 kg and covers the wavelength range from 0.3 to 9.5 microns. Additional lightweight technologies (inertial measurement units, reaction wheels, batteries, computing systems, and solid state recorders) have also been incorporated in the basic system design. On 3 May, 1994 the spacecraft will leave lunar orbit. Following an additional 2 Earth flybys, and a lunar flyby, the spacecraft will then execute a flyby of the the near-Earth-asteroid 1620 Geographos, around 31 August 1994. An extended mission to flyby near-Earth asteroid 1983 RD in October of 1995 is currently under study. A great deal of significant information will be returned by Clementine during its two months in lunar orbit. The data (which would fill a small library of compact discs) will be distributed through NASA's Planetary Data System, a nationwide system of repositories for lunar and planetary flight data that is widely available to scientists. Images are also available to the public on Internet using "anonymous ftp" at clementine.s1.gov.

Nozette, Stewart

1995-01-01

11

Opposition Effect from Clementine Data and Mechanisms of Backscatter  

Microsoft Academic Search

An analysis of Clementine data obtained from a UVVIS camera and simulating laboratory photometric and polarimetric measurements is presented with the use of a new photometric three-parameter function combining the shadow-hiding and coherent backscatter mechanisms. The fit of calculated curves to the average brightness phase function of the Moon derived from Clementine data indicates that the coherent backscatter component is

Yu. G. Shkuratov; M. A. Kreslavsky; A. A. Ovcharenko; D. G. Stankevich; E. S. Zubko; C. Pieters; G. Arnold

1999-01-01

12

Clementine High Resolution Camera Mosaicking Project  

NASA Astrophysics Data System (ADS)

This compact disk (CD) is part of the Malin Space Science Systems (MSSS) effort to mosaic Clementine I high resolution (HiRes) camera lunar images. These mosaics were developed through calibration and semi-automated registration against the recently released geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic, which is available through the PDS, as CD-ROM volumes CL_3001-3015. The HiRes mosaics are compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution observations from the HiRes imaging system onboard the Clementine Spacecraft. These mosaics are spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel. The geometric control is provided by the 100 m/pixel U.S. Geological Survey (USGS) Clementine Basemap Mosaic compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Calibration was achieved by removing the image nonuniformity largely caused by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap that approximately transform the 8-bit HiRes data to photometric units. The mosaics on this CD were compiled from sub-polar data (latitudes 80 degrees South to 80 degrees North; -80 to +80) within the longitude range 0-30 deg E. The mosaics are divided into tiles that cover approximately 1.75 degrees of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. This CD contains ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files. For more information on the contents and organization of the CD volume set refer to the "FILES, DIRECTORIES AND DISK CONTENTS" section of this document. The image files are organized according to NASA's Planetary Data System (PDS) standards. An image file (tile) is organized as a PDS labeled file containing an "image object".

Malin, Michael; Revine, Michael

1998-10-01

13

Clementine High Resolution Camera Mosaicking Project  

NASA Astrophysics Data System (ADS)

This compact disk (CD) is part of the Malin Space Science Systems (MSSS) effort to mosaic Clementine I high resolution (HiRes) camera lunar images. These mosaics were developed through calibration and semi-automated registration against the recently released geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic, which is available through the PDS, as CD-ROM volumes CL_3001-3015. The HiRes mosaics are compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution observations from the HiRes imaging system onboard the Clementine Spacecraft. These mosaics are spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel. The geometric control is provided by the 100 m/pixel U. S. Geological Survey (USGS) Clementine Basemap Mosaic compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Calibration was achieved by removing the image nonuniformity largely caused by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap that approximately transform the 8-bit HiRes data to photometric units. The mosaics on this CD were compiled from sub-polar data (latitudes 80 degrees South to 80 degrees North; -80 to +80) within the longitude range 0-30 deg E. The mosaics are divided into tiles that cover approximately 1.75 degrees of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. This CD contains ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files. For more information on the contents and organization of the CD volume set refer to the "FILES, DIRECTORIES AND DISK CONTENTS" section of this document. The image files are organized according to NASA's Planetary Data System (PDS) standards. An image file (tile) is organized as a PDS labeled file containing an "image object".

Malin, Michael; Revine, Michael

1998-10-01

14

Clementine High Resolution Camera Mosaicking Project  

NASA Astrophysics Data System (ADS)

This report constitutes the final report for NASA Contract NASW-5054. This project processed Clementine I high resolution images of the Moon, mosaicked these images together, and created a 22-disk set of compact disk read-only memory (CD-ROM) volumes. The mosaics were produced through semi-automated registration and calibration of the high resolution (HiRes) camera's data against the geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic produced by the US Geological Survey (USGS). The HiRes mosaics were compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution nadir-looking observations. The images were spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel for sub-polar mosaics (below 80 deg. latitude) and using the stereographic projection at a scale of 30 m/pixel for polar mosaics. Only images with emission angles less than approximately 50 were used. Images from non-mapping cross-track slews, which tended to have large SPICE errors, were generally omitted. The locations of the resulting image population were found to be offset from the UV/Vis basemap by up to 13 km (0.4 deg.). Geometric control was taken from the 100 m/pixel global and 150 m/pixel polar USGS Clementine Basemap Mosaics compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Radiometric calibration was achieved by removing the image nonuniformity dominated by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap, that approximately transform the 8-bit HiRes data to photometric units. The sub-polar mosaics are divided into tiles that cover approximately 1.75 deg. of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. Polar mosaics are tiled into squares 2250 pixels on a side, which spans approximately 2.2 deg. Two mosaics are provided for each pole: one corresponding to data acquired while periapsis was in the south, the other while periapsis was in the north. The CD-ROMs also contain ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files.

1998-10-01

15

Clementine High Resolution Camera Mosaicking Project  

NASA Astrophysics Data System (ADS)

This compact disk (CD) is part of the Clementine I high resolution (HiRes) camera lunar image mosaics developed by Malin Space Science Systems (MSSS). These mosaics were developed through calibration and semi-automated registration against the recently released geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic, which is available through the PDS, as CD-ROM volumes CL_3001-3015. The HiRes mosaics are compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution observations from the HiRes imaging system onboard the Clementine Spacecraft. The geometric control is provided by the U.S. Geological Survey (USGS) Clementine Basemap Mosaic compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Calibration was achieved by removing the image nonuniformity largely caused by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap that approximately transform the 8-bit HiRes data to photometric units. The mosaics on this CD are compiled from polar data (latitudes greater than 80 degrees), and are presented in the stereographic projection at a scale of 30 m/pixel at the pole, a resolution 5 times greater than that (150 m/pixel) of the corresponding UV/Vis polar basemap. This 5:1 scale ratio is in keeping with the sub-polar mosaic, in which the HiRes and UV/Vis mosaics had scales of 20 m/pixel and 100 m/pixel, respectively. The equal-area property of the stereographic projection made this preferable for the HiRes polar mosaic rather than the basemap's orthographic projection. Thus, a necessary first step in constructing the mosaic was the reprojection of the UV/Vis basemap to the stereographic projection. The HiRes polar data can be naturally grouped according to the orbital periapsis, which was in the south during the first half of the mapping mission and in the north during the second half. Images in each group have generally uniform intrinsic resolution, illumination, exposure and gain. Rather than mingle data from the two periapsis epochs, separate mosaics are provided for each, a total of 4 polar mosaics. The mosaics are divided into 100 square tiles of 2250 pixels (approximately 2.2 deg near the pole) on a side. Not all squares of this grid contain HiRes mosaic data, some inevitably since a square is not a perfect representation of a (latitude) circle, others due to the lack of HiRes data. This CD also contains ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files. For more information on the contents and organization of the CD volume set refer to the "FILES, DIRECTORIES AND DISK CONTENTS" section of this document. The image files are organized according to NASA's Planetary Data System (PDS) standards. An image file (tile) is organized as a PDS labeled file containing an "image object".

Malin, Michael; Revine, Michael

1998-10-01

16

Clementine High Resolution Camera Mosaicking Project  

NASA Astrophysics Data System (ADS)

This compact disk (CD) is part of the Clementine I high resolution (HiRes) camera lunar image mosaics developed by Malin Space Science Systems (MSSS). These mosaics were developed through calibration and semi-automated registration against the recently released geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic, which is available through the PDS, as CD-ROM volumes CL_3001-3015. The HiRes mosaics are compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution observations from the HiRes imaging system onboard the Clementine Spacecraft. The geometric control is provided by the U. S. Geological Survey (USGS) Clementine Basemap Mosaic compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Calibration was achieved by removing the image nonuniformity largely caused by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap that approximately transform the 8-bit HiRes data to photometric units. The mosaics on this CD are compiled from polar data (latitudes greater than 80 degrees), and are presented in the stereographic projection at a scale of 30 m/pixel at the pole, a resolution 5 times greater than that (150 m/pixel) of the corresponding UV/Vis polar basemap. This 5:1 scale ratio is in keeping with the sub-polar mosaic, in which the HiRes and UV/Vis mosaics had scales of 20 m/pixel and 100 m/pixel, respectively. The equal-area property of the stereographic projection made this preferable for the HiRes polar mosaic rather than the basemap's orthographic projection. Thus, a necessary first step in constructing the mosaic was the reprojection of the UV/Vis basemap to the stereographic projection. The HiRes polar data can be naturally grouped according to the orbital periapsis, which was in the south during the first half of the mapping mission and in the north during the second half. Images in each group have generally uniform intrinsic resolution, illumination, exposure and gain. Rather than mingle data from the two periapsis epochs, separate mosaics are provided for each, a total of 4 polar mosaics. The mosaics are divided into 100 square tiles of 2250 pixels (approximately 2.2 deg near the pole) on a side. Not all squares of this grid contain HiRes mosaic data, some inevitably since a square is not a perfect representation of a (latitude) circle, others due to the lack of HiRes data. This CD also contains ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files. For more information on the contents and organization of the CD volume set refer to the "FILES, DIRECTORIES AND DISK CONTENTS" section of this document. The image files are organized according to NASA's Planetary Data System (PDS) standards. An image file (tile) is organized as a PDS labeled file containing an "image object".

Malin, Michael; Revine, Michael

1998-10-01

17

Clementine Star-Tracker Images of the Inner Zodiacal Light  

Microsoft Academic Search

Excellent photographs of the inner zodiacal light, using the Moon as an occulting disk, have been obtained with the Clementine star-tracker cameras. With exposures that vary from 50 milliseconds to 700 milliseconds, with a dynamic range of 256 for each exposure, and with a 28.9 degree by 43.4 degree field of view, the Clementine cameras have recorded the zodiacal light

B. L. Cooper; H. A. Zook; J. M. Hahn; A. E. Potter

2000-01-01

18

Charged-particle telescope experiment on Clementine.  

PubMed

The charged-particle telescope (CPT) onboard the Clementine spacecraft measured the fluxes of energetic protons emitted in solar energetic particle events. Protons in the energy range from 10 to 80 MeV were of greatest interest for radiation effects such as total dose and single event upsets. Energetic electrons were also of interest for spacecraft charging and their contribution to total dose. The lower-energy CPT electron channels (25-500 keV) were mainly of geophysical interest. While orbiting the moon, the CPT observed the wake created by the moon when it blocked the flow of energetic particles in the magnetotail region. The CPT provided opportunities to observe energetic electron bursts during magnetic storms and magnetospheric substorms. CPT data are particularly useful in multispacecraft studies of interplanetary disturbances and their interaction with the magnetosphere. The proton channels on the CPT provided data on solar energetic protons and storm-time protons associated with the passage of an interplanetary shock at 0903 UT on Feb. 21, 1994. Results are compared with those from GOES-7, SAMPEX, and GEOTAIL. PMID:11539374

Baker, D N; Kanekal, S; Blake, J B; Adams, J H

19

Quality of Clementine Jam Infl uenced by Purée Pretreatment, Sugar Type and Pectin Addition  

Microsoft Academic Search

Summary Th e aim of this research was to investigate the infl uence of several parameters on quality of Clementine (Citrus clementine) jam. Th ermal treated and nontreated Clementine purée, two types of sugar (sucrose and fructose) and three diff erent amounts of added pectin were used for the jam producing. Accordingly, twelve jams were prepared and sorted in four

Branka LEVAJ

2009-01-01

20

Global Comparisons of Mare Basalt Types from Clementine Multispectral Data  

Microsoft Academic Search

The compositions of mare basalts have been examined on a global scale using multispectral images obtained by the Clementine spacecraft. Based on well-documented trends in the optical weathering of mare materials (Staid and Pieters, Icarus, 2000), relatively uncontaminated mare surfaces were identified within fourteen separate deposits. The spectral properties of mature soils and more crystalline mare materials from each deposit

M. I. Staid; C. M. Pieters

2001-01-01

21

The Clementine Mission to the Moon: Scientific Overview  

Microsoft Academic Search

In the course of 71 days in lunar orbit, from 19 February to 3 May 1994, the Clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths. These data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar

Stewart Nozette; I. T. Lewis; C. L. Lichtenberg; D. M. Horan; E. Malaret; E. M. Shoemaker; J. H. Resnick; C. J. Rollins; D. N. Baker; J. E. Blamont; B. J. Buratti; C. M. Pieters; M. E. Davies; M. S. Robinson; E. M. Eliason; B. M. Jakosky; T. C. Sorenson; R. W. Vorder Bruegge; P. G. Lucey; M. A. Massie; H. S. Park; A. S. McEwen; R. E. Priest; R. A. Reisse; R. A. Simpson; D. E. Smith; R. W. Vorder Breugge; M. T. Zuber

1994-01-01

22

Mineralogy of the lunar crust: Results from Clementine  

Microsoft Academic Search

The central peaks of 109 impact craters across the Moon are examined with Clementine UVVIS camera multispectral data. The craters range in diameter from 40 to 180 km, and are believed to have exhumed material from 5 - 30 km beneath the surface to form the peaks, including both upper and lower crustal rocks depending on whether craters have impacted

Stefanie Tompkins; Carle M. Pieters

1999-01-01

23

Clementine Observations of the Aristarchus Region of the Moon  

Microsoft Academic Search

Multispectral and topographic data acquired by the Clementine spacecraft provide information on the composition and geologic history of the Aristarchus region of the moon. Altimetry profiles show the Aristarchus plateau dipping about 1^circ to the north-northwest and rising about 2 kilometers above the surrounding lavas of Oceanus Procellarum to the south. Dark, reddish pyroclastic glass covers the plateau to average

Alfred S. McEwen; Mark S. Robinson; Eric M. Eliason; Paul G. Lucey; Tom C. Duxbury; Paul D. Spudis

1994-01-01

24

UV/visible camera for the Clementine mission  

SciTech Connect

This article describes the Clementine UV/Visible (UV/Vis) multispectral camera, discusses design goals and preliminary estimates of on-orbit performance, and summarizes lessons learned in building and using the sensor. While the primary objective of the Clementine Program was to qualify a suite of 6 light-weight, low power imagers for future Department of Defense flights, the mission also has provided the first systematic mapping of the complete lunar surface in the visible and near-infrared spectral regions. The 410 g, 4.65 W UV/Vis camera uses a 384 x 288 frame-transfer silicon CCD FPA and operates at 6 user-selectable wavelength bands between 0.4 and 1.1 {micro}m. It has yielded lunar imagery and mineralogy data with up to 120 in spatial resolution (band dependent) at 400 km periselene along a 39 km cross-track swath.

Kordas, J.F.; Lewis, I.T.; Priest, R.E. [and others

1995-04-01

25

Star tracker stellar compass for the Clementine mission  

Microsoft Academic Search

The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared region. More than 1.7 million images of the moon, earth and space were returned from this mission. Two star tracker stellar compasses (star tracker camera + stellar compass software) were included on the spacecraft, serving a primary function of providing

Joseph F. Kordas; Isabella T. Lewis; Bruce A. Wilson; Darron P. Nielsen; Hye-Sook Park; Robert E. Priest; Robert F. Hills; Michael J. Shannon; Arno G. Ledebuhr; Lyn D. Pleasance

1995-01-01

26

Aristarchus Plateau: Clementine Spectro-Imaging and Geological Inferences  

Microsoft Academic Search

A detailed remote sensing survey of the Aristarchus Plateau has been made in the UV-visible- near infrared domain by means of earth-based telescopic and Clementine CCD spectro-imaging techniques and the distribution of the main types of materials is proposed on the basis of their spectral characteristics. Following a preliminary investigation using a principal component (PCA) analysis, a spectral mixture analysis,

P. C. Pinet; P. Martin; F. Costard; S. Chevrel; Y. Daydou; P. E. Johnson

1996-01-01

27

Back to the moon, on to an asteroid - The Clementine mission  

NASA Astrophysics Data System (ADS)

A Clementine mission scheduled for launch in 1994 to space-qualify a set of lightweight electronic cameras for the Department of Defense to use in detecting and tracking ballistic missiles is described. Clementine will carry instruments that are sensitive in several portions of the electromagnetic spectrum. These instruments will include an UV/visible CCD camera, NIR and long-wavelength infrared cameras, and a combined high-resolution CCD camera and laser ranging system (LIDAR). The Clementine spacecraft weighs about 220 kg and will be launched on a refurbished Titan IIG missile.

Nozette, Stewart; Shoemaker, Eugene M.

1993-10-01

28

Analysis of Global Lunar Iron Abundances: A Systematic Comparison of Lunar Prospector and Clementine Data  

NASA Astrophysics Data System (ADS)

Analyses of Lunar Prospector and Clementine global iron maps show significant differences between these datasets for specific portions of the lunar surface. We use forward modeling of gamma ray data to investigate discrepant regions of interest.

Hagerty, J. J.; Lawrence, D. J.; Cahill, J. T. S.; Klima, R. L.; Gillis-Davis, J. J.

2012-03-01

29

Mapping Homogeneous Mare Basalt Units in the Aristarchus Quadrangle Using Clementine Spectral Parameters  

NASA Astrophysics Data System (ADS)

In our work, multi-dimensional spatial distribution of several Clementine spectral parameters was used to identify and determine basalt units, which related to the composition of the lunar interior and its thermal evolution.

Zhang, F.; Zou, Y. L.; Zheng, Y. C.; Fu, X. H.

2012-03-01

30

Colorful Views of the Moon: Comparing Spectra from Clementine and the Moon Mineralogy Mapper  

Microsoft Academic Search

M3 spectra derived from immature craters show a significantly increased spectral contrast compared with their Clementine counterparts. The M3 data set improves our ability to interpret mineralogy, petrology, surface and subsurface processes.

G. Kramer; J.-P. Combe; T. McCord; C. Pieters; J. Head; L. Taylor; M. Staid

2010-01-01

31

Clementine observations of the Aristarchus region of the moon  

USGS Publications Warehouse

Multispectral and topographic data acquired by the Clementine spacecraft provide information on the composition and geologic history of the Aristarchus region of the moon. Altimetry profiles show the Aristarchus plateau dipping about 1?? to the north-northwest and rising about 2 kilometers above the surrounding lavas of Oceanus Procellarum to the south. Dark, reddish pyroclastic glass covers the plateau to average depths of 10 to 30 meters, as determined from the estimated excavation depths of 100- to 1000-meter-diameter craters that have exposed materials below the pyroclastics. These craters and the wall of sinuous rilles also show that mare basalts underlie the pyroclastics across much of the plateau. Near-infrared images of Aristarchus crater reveal oilvine-rich materials and two kilometer-sized outcrops of anorthosite in the central peaks. The anorthosite could be either a derivative of local magnesium-suite magmatism or a remnant of the ferroan anorthosite crust that formed over the primordial magma ocean.

McEwen, A. S.; Robinson, M. S.; Eliason, E. M.; Lucey, P. G.; Duxbury, T. C.; Spudis, P. D.

1994-01-01

32

The clementine mission to the moon: scientific overview.  

PubMed

In the course of 71 days in lunar orbit, from 19 February to 3 May 1994, the Clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths. These data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar polar regions and the lunar far side. In addition, laser-ranging measurements provided the first view of the global topographic figure of the moon. The topography of many ancient impact basins has been measured, and a global map of the thickness of the lunar crust has been derived from the topography and gravity. PMID:17737076

Nozette, S; Rustan, P; Pleasance, L P; Kordas, J F; Lewis, I T; Park, H S; Priest, R E; Horan, D M; Regeon, P; Lichtenberg, C L; Shoemaker, E M; Eliason, E M; McEwen, A S; Robinson, M S; Spudis, P D; Acton, C H; Buratti, B J; Duxbury, T C; Baker, D N; Jakosky, B M; Blamont, J E; Corson, M P; Resnick, J H; Rollins, C J; Davies, M E; Lucey, P G; Malaret, E; Massie, M A; Pieters, C M; Reisse, R A; Simpson, R A; Smith, D E; Sorenson, T C; Breugge, R W; Zuber, M T

1994-12-16

33

A sharper view of impact craters from clementine data.  

PubMed

The ultraviolet-visible camera on the Clementine spacecraft obtained high-spatial resolution images of the moon in five spectral channels. Impact craters mapped with these multispectral images show a scale of lithologic diversity that varies with crater size and target stratigraphy. Prominent lithologic variations (feldspathic versus basaltic) occur within the south wall of Copernicus (93 kilometers in diameter) on the scale of 1 to 2 kilometers. Lithologic diversity at Tycho (85 kilometers in diameter) is less apparent at this scale, although the impact melt of these two large craters is remarkably similar in this spectral range. The lunar surface within and around the smaller crater Giordano Bruno (22 kilometers in diameter) is largely dominated by the mixing of freshly excavated material with surrounding older soils derived from a generally similar feldspathic lithology. PMID:17737078

Pieters, C M; Staid, M I; Fischer, E M; Tompkins, S; He, G

1994-12-16

34

Radiation effects in space: The Clementine I mission  

SciTech Connect

The space radiation environment for the CLEMENTINE I mission was investigated using a new calculational model, CHIME, which includes the effects of galactic cosmic rays (GCR), anomalous component (AC) species and solar energetic particle (SEP) events and their variations as a function of time. Unlike most previous radiation environment models, CHIME is based upon physical theory and is {open_quotes}calibrated{close_quotes} with energetic particle measurements made over the last two decades. Thus, CHIME provides an advance in the accuracy of estimating the interplanetary radiation environment. Using this model we have calculated particle energy spectra, fluences and linear energy transfer (LET) spectra for all three major components of the CLEMENTINE I mission during 1994: (1) the spacecraft in lunar orbit, (2) the spacecraft during asteroid flyby, and (3) the interstate adapter USA in Earth orbit. Our investigations indicate that during 1994 the level of solar modulation, which dominates the variation in the GCR and AC flux as a function of time, will be decreasing toward solar minimum levels. Consequently the GCR and AC flux will be increasing during Y, the year and, potentially, will rise to levels seen during previous solar minimums. The estimated radiation environment also indicates that the AC will dominate the energetic particle spectra for energies below 30-50 MeV/nucleon, while the GCR have a peak flux at {approximately}300 MeV/nucleon and maintain a relatively high flux level up to >1000 MeV/nucleon. The AC significantly enhances the integrated flux for LET in the range 1 to 10 MeV/(mg/cm{sup 2}), but due to the steep energy spectra of the AC a relatively small amount of material ({approximately}50 mils of Al) can effectively shield against this component. The GCR are seen to be highly penetrating and require massive amounts of shielding before there is any appreciable decrease in the LET flux.

Guzik, T.G.; Clayton, E.; Wefel, J.P.

1994-12-20

35

Newer views of the Moon: Comparing spectra from Clementine and the Moon Mineralogy Mapper  

USGS Publications Warehouse

The Moon Mineralogy Mapper (M3) provided the first global hyperspectral data of the lunar surface in 85 bands from 460 to 2980 nm. The Clementine mission provided the first global multispectral maps the lunar surface in 11 spectral bands across the ultraviolet-visible (UV-VIS) and near-infrared (NIR). In an effort to understand how M3 improves our ability to analyze and interpret lunar data, we compare M3 spectra with those from Clementine's UV-VIS and NIR cameras. The Clementine mission provided the first global multispectral maps the lunar surface in 11 spectral bands across the UV-VIS and NIR. We have found that M3 reflectance values are lower across all wavelengths compared with albedos from both of Clementine's UV-VIS and NIR cameras. M3 spectra show the Moon to be redder, that is, have a steeper continuum slope, than indicated by Clementine. The 1 m absorption band depths may be comparable between the instruments, but Clementine data consistently exhibit shallower 2 m band depths than M 3. Absorption band minimums are difficult to compare due to the significantly different spectral resolutions. Copyright 2011 by the American Geophysical Union.

Kramer, G. Y.; Besse, S.; Nettles, J.; Combe, J. -P.; Clark, R. N.; Pieters, C. M.; Staid, M.; Malaret, E.; Boardman, J.; Green, R. O.; Head, J. W.; McCord, T. B.

2011-01-01

36

Newer views of the Moon: Comparing spectra from Clementine and the Moon Mineralogy Mapper  

NASA Astrophysics Data System (ADS)

The Moon Mineralogy Mapper (M3) provided the first global hyperspectral data of the lunar surface in 85 bands from 460 to 2980 nm. The Clementine mission provided the first global multispectral maps the lunar surface in 11 spectral bands across the ultraviolet-visible (UV-VIS) and near-infrared (NIR). In an effort to understand how M3 improves our ability to analyze and interpret lunar data, we compare M3 spectra with those from Clementine's UV-VIS and NIR cameras. The Clementine mission provided the first global multispectral maps the lunar surface in 11 spectral bands across the UV-VIS and NIR. We have found that M3 reflectance values are lower across all wavelengths compared with albedos from both of Clementine's UV-VIS and NIR cameras. M3 spectra show the Moon to be redder, that is, have a steeper continuum slope, than indicated by Clementine. The 1 ?m absorption band depths may be comparable between the instruments, but Clementine data consistently exhibit shallower 2 ?m band depths than M3. Absorption band minimums are difficult to compare due to the significantly different spectral resolutions.

Kramer, Georgiana Y.; Besse, Sebastien; Nettles, Jeffrey; Combe, Jean-Philippe; Clark, Roger N.; Pieters, Carlé M.; Staid, Matthew; Malaret, Erik; Boardman, Joseph; Green, Robert O.; Head, James W., III; McCord, Thomas B.

2011-04-01

37

Lunar South Pole Topography Derived from Clementine Imagery  

NASA Astrophysics Data System (ADS)

During the Clementine Mission both oblique and vertical multispectral images were collected. The oblique and vertical images from a single spectral band collected during the same orbit form a stereo pair that can be used to derive the topography. These stereo pairs are being used to derive the topography of an area (90 deg S to 650S latitude) surrounding the lunar south pole. Work on the lunar north pole topography will start after completion of the south pole topography. This report provides an update on the initial results for the lunar south pole topography. In 1994, the Clementine spacecraft acquired digital images of the Moon at visible and near-infrared wavelengths. Onboard there were four camera systems and a laser altimeter. During the first pass, periapsis was at 30S and the highest resolution images were obtained in the southern hemisphere. Over the northern polar area, a series of oblique and vertical images were obtained with the ultraviolet-visible (UV-VIS) camera on each orbit. During the second pass, periapsis was at 30N and the image acquisition strategy was reversed. The UV-VIS camera image size was 384 x 288 pixels with five spectral bands and one broad band. The 750-nm-band stereo pairs are the primary image source for this study. The ground sample distances (GSD) for oblique images range from 300 to 400m. The GSD for the vertical images, acquired at the end of an orbit, are slightly larger and range from 325 to 450 m. Using the formula for stereo-height accuracy, an estimate of height accuracy is 180m. This formula is IFOVMAX)/(K*B/H with IFOVMAX defined as Maximum Instantaneous Field of View; B/H is the base-to-height ratio and K is an estimate of pixel measurement accuracy on the imagery. The Clementine laser altimeter (LIDAR) data were used previously to produce a global topographic model of the Moon . The model has a vertical accuracy of about 100 m and a spatial resolution of 2.5 deg. Altimetry data were collected between 79S and 810N. These data were filtered and then interpolated to fill in the polar regions where the altimeter did not collect data. A global topography model was then derived based on spherical harmonic expansion. Image mosaic. A global image mosaic of the Moon was produced from the 750-nm. Clementine data . The mosaic includes high-resolution, oblique, and vertical images. Match points were picked to tie the imagery together, and the camera pointing angles were adjusted to align the imagery. This adjustment used a spherical surface, and the elevation of all points was held to a constant value, 1737.4 km. This produced a seamless image mosaic with latitude and longitude information but no information on the elevation. The imagery and support information were downloaded to our digital photogrammetric workstation from the Integrated Software for Imagers and Spectrometers (ISIS) system. The support data included the camera location and pointing angles. Match points used to, produce the image mosaic were also downloaded. The camera angles were adjusted to account for the elevation of the match points. This was accomplished with the Multi Sensor Triangulation (MST) software from LH Systems SOCET Set software package. The revised camera angles allowed for the derivation of a digital elevation model (DEM) from the stereo pairs. The match-point latitude and longitude from the global image mosaic are accurate and used for an initial estimate of the horizontal position. The elevations of the match points were estimated from the altimetry data. The camera angles used in the altimetry processing and in the creation of the image mosaic were adjusted independently. Hence, the horizontal position of the altimetry data and the image mosaic are not aligned correctly. Clementine was designed so the altimeter shared the optical system of the HIRES camera system. The HIRES and UV-VIS camera systems were aligned so the HIRES image was centered in the UV-VIS image. We therefore made an adjustment so that the altimetry points would fall near the centerline of the UV-VIS imagery. A DEM was created from

Rosiek, M. R.; Kirk, R.; Howington-Kraus, A.

1999-01-01

38

Topography of the Moon from the Clementine LIDAR  

NASA Astrophysics Data System (ADS)

Range measurements from the lidar instrument carried aboard the Clementine spacecraft have been used to produce an accurate global topographic model of the Moon. This paper discusses the function of the lidar; the acquisition, processing, and filtering of observations to produce a global topographic model; and the determination of parameters that define the fundamental shape of the Moon. Our topographic model: a 72nd degree and order spherical harmonic expansion of lunar radii, is designated Goddard Lunar Topography Model 2 (GLTM 2). This topographic field has an absolute vertical accuracy of approximately 100 m and a spatial resolution of 2.5 deg. The field shows that the Moon can be described as a sphere with maximum positive and negative deviations of approx. 8 km, both occurring on the farside, in the areas of the Korolev and South Pole-Aitken (S.P.-Aitken) basins. The amplitude spectrum of the topography shows more power at longer wavelengths as compared to previous models, owing to more complete sampling of the surface, particularly the farside. A comparison of elevations derived from the Clementine lidar to control point elevations from the Apollo laser altimeters indicates that measured relative topographic heights generally agree to within approx. 200 in over the maria. While the major axis of the lunar gravity field is aligned in the Earth-Moon direction, the major axis of topography is displaced from this line by approximately 10 deg to the cast and intersects the farside 24 deg north of the equator. The magnitude of impact basin topography is greater than the lunar flattening (approx. 2 km) and equatorial ellipticity (approx. 800 m), which imposes a significant challenge to interpreting the lunar figure. The floors of mare basins are shown to lie close to an equipotential surface, while the floors of unflooded large basins, except for S.P.-Aitken, lie above this equipotential. The radii of basin floors are thus consistent with a hydrostatic mechanism for the absence of significant farside maria except for S.P.-Aitken, whose depth and lack of mare require significant internal compositional and/or thermal heterogeneity. A macroscale surface roughness map shows that roughness at length scales of 101 - 102 km correlates with elevation and surface age.

Smith, David E.; Zuber, Maria T.; Neumann, Gregory A.; Lemoine, Frank G.

1997-01-01

39

Photometric anomalies of the lunar surface: Results from Clementine data  

NASA Astrophysics Data System (ADS)

We mapped the photometric characteristics of the lunar surface for several small areas using Clementine UVVIS camera images. The maps of the phase function steepness showed several anomalous sites. Several small fresh impact craters have anomalous halos in these maps. The phase function within the halos is less steep than for the surrounding mare surface. We interpret these halos to be due to geologically recent impact-caused alteration of the equilibrium millimeter-scale regolith structure. This equilibrium structure is established through micrometeoritic bombardment at a geologically short timescale. An anomaly of the same signature was found at the Apollo 15 landing site. We interpret it as being a result of the regolith structure alteration with the lander jets. A unique photometric anomaly not correlated with albedo was found within the Reiner Gamma Formation. We suggest that this anomaly is genetically related to the formation, which indicates its young age. This favors the impact hypothesis for the nature of the Reiner Gamma Formation. Our study showed that mapping of photometric characteristics is a new powerful tool in studies of the surfaces of atmosphereless bodies. Future photometric studies of the Moon with existing and new data sets are promising for a search for traces of recent seismic events, studies of the recent population of meteoroids in the inner solar system, an advance in the understanding of swirls, etc.

Kreslavsky, M. A.; Shkuratov, Y. G.

2003-03-01

40

Clementine observations of the aristarchus region of the moon.  

PubMed

Multispectral and topographic data acquired by the Clementine spacecraft provide information on the composition and geologic history of the Aristarchus region of the moon. Altimetry profiles show the Aristarchus plateau dipping about 1 degrees to the north-northwest and rising about 2 kilometers above the surrounding lavas of Oceanus Procellarum to the south. Dark, reddish pyroclastic glass covers the plateau to average depths of 10 to 30 meters, as determined from the estimated excavation depths of 100- to 1000-meter-diameter craters that have exposed materials below the pyroclastics. These craters and the walls of sinuous rilles also show that mare basalts underlie the pyroclastics across much of the plateau. Near-infrared images of Aristarchus crater reveal olivine-rich materials and two kilometer-sized outcrops of anorthosite in the central peaks. The anorthosite could be either a derivative of local magnesium-suite magmatism or a remnant of the ferroan anorthosite crust that formed over the primordial magma ocean. PMID:17737082

McEwen, A S; Robinson, M S; Eliason, E M; Lucey, P G; Duxbury, T C; Spudis, P D

1994-12-16

41

Near-infrared camera for the Clementine mission  

SciTech Connect

The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. The near-infrared (NIR) multi-spectral camera, one of two workhorse lunar mapping cameras (the other being the UV/visible camera), provided {approximately}200 in spatial resolution at 400 km periselene, and a 39 km across-track swath. This 1.9 kg infrared camera using a 256 x 256 InSb FPA viewed reflected solar illumination from the lunar surface and lunar horizon in the 1 to 3 {micro}m wavelength region, extending lunar imagery and mineralogy studies into the near infrared. A description of this light-weight, low power NIR camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights.

Priest, R.E.; Lewis, I.T.; Sewall, N.R.; Park, H.S.; Shannon, M.J.; Ledebuhr, A.G.; Pleasance, L.D. [Lawrence Livermore National Lab., CA (United States); Massie, M.A. [Pacific Advanced Technology, Solvang, CA (United States); Metschuleit, K. [Amber/A Raytheon Co., Goleta, CA (United States)

1995-04-01

42

Automated identification of basalt spectra in Clementine lunar data  

NASA Astrophysics Data System (ADS)

The identification of fresh basalt spectra plays an important role in lunar stratigraphic studies; however, the process can be time consuming and labor intensive. Thus motivated, we developed an empirically derived algorithm for the automated identification of fresh basalt spectra from Clememtine UVVIS data. This algorithm has the following four parameters and limits: BC Ratio=3( R950- R900)/( R900- R750)<1.1, CD Delta=( R1000- R950)/ R750-1.09( R950- R900)/ R750>0.003 and <0.06, B Slope=( R900- R750)/(3 R750)<-0.012, and Band Depth=( R750- R950)/( R750- R415)>0.1, where R750 represents the unnormalized reflectance of the 750 nm Clementine band, and so on. Algorithm results were found to be accurate to within an error of 4.5% with respect to visual classification, though olivine spectra may be under-represented. Overall, fresh basalts identified by the algorithm are consistent with expectations and previous work in the Mare Humorum area, though accuracy in other areas has not yet been tested. Great potential exists in using this algorithm for identifying craters that have excavated basalts, estimating the thickness of mare and cryptomare deposits, and other applications.

Antonenko, I.; Osinski, G. R.

2011-06-01

43

Global Comparisons of Mare Basalt Types from Clementine Multispectral Data  

NASA Astrophysics Data System (ADS)

The compositions of mare basalts have been examined on a global scale using multispectral images obtained by the Clementine spacecraft. Based on well-documented trends in the optical weathering of mare materials (Staid and Pieters, Icarus, 2000), relatively uncontaminated mare surfaces were identified within fourteen separate deposits. The spectral properties of mature soils and more crystalline mare materials from each deposit were then compared among regions to assess the compositional diversity of nearside and farside lunar volcanism. Abundant highland contamination within the farside maria may contribute to previous classifications of these deposits as homogenous flows with high albedos, weak mafic bands and intermediate titanium contents. The identification of relatively uncontaminated mare materials provides a more accurate assessment of the composition of the basalts originally emplaced within each study region. A variety of spectrally distinct basalts are identified on the farside that represent a wide range of the diversity observed on the nearside. Examination of the freshest uncontaminated basalts associated with mare craters reveals that the mafic band shape of farside deposits also falls within the range of compositions observed on the nearside. The farside mare deposits are dominated by high albedo basalts with low iron and titanium abundances that appear to be associated with their emplacement through a thick feldspathic crust. Similar deposits are observed outside of the major basins on the nearside. However, regions of thin crust and low topography on the farside display a larger variety of basalt types including more iron and titanium rich basalts similar to those found in the major nearside basins. The last major eruptions of mare basalts, which occurred within the nearside Oceanus Procellarum and Imbrium regions, were observed to have unique spectral properties relative to all earlier mare deposits. The optical properties of these late-stage basalts indicate that they represent a unique combination of an iron-rich composition, and an ilmenite and olivine-rich mineralogy.

Staid, M. I.; Pieters, C. M.

2001-05-01

44

Clementine Star Tracker Stellar Compass: Final report part 1  

SciTech Connect

The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. Two star stracker stellar compasses (star tracker camera + stellar compass software) were included on the spacecraft, serving a primary function of providing angle updates to the guidance and navigation system. These cameras served a secondary function by providing a wide field of view imaging capability for lunar horizon glow and other dark-side imaging data. This 290 g camera using a 576 x 384 focal plane array and a 17 mm entrance pupil, detected and centroided stars as dim and dimmer than 4.5 m{sub v}, providing rms pointing accuracy of better than 100 {mu}rad pitch and yaw and 450 {mu}rad roll. A description of this light-weight, low power star tracker camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights. Documentation generated during the design, analysis, build, test and characterization of the star tracker cameras are presented. Collectively, this documentation represents a small library of information for this camera, and may be used as a framework for producing copy units by commercial enterprises, and therefore satisfies a Department of Defense and Department of Energy goal to transfer technology to industry. However, the considerable knowledge gained from the experience of the individuals involved in the system trades, design, analysis, production, testing and characterization of the star tracker stellar compass is not contained in this documentation.

Priest, R.E.; Kordas, J.F.; Lewis, I.T. [and others

1995-07-01

45

Overview of the fast reactors fuels program. [LMFBR  

Microsoft Academic Search

Each nation involved in LMFBR development has its unique energy strategies which consider energy growth projections, uranium resources, capital costs, and plant operational requirements. Common to all of these strategies is a history of fast reactor experience which dates back to the days of the Manhatten Project and includes the CLEMENTINE Reactor, which generated a few watts, LAMPRE, EBR-I, EBR-II,

E. A. Evans; C. M. Cox; B. R. Hayward; L. H. Rice; H. H. Yoshikawa

1980-01-01

46

The Mare Humorum region of the moon - New optical, compositional, and geological inferences from Clementine  

Microsoft Academic Search

The present paper deals with a detailed assessment of the surface properties in the Mare Humorum region of the moon. Spectral investigations have been made by means of the processing and analysis of Clementine UV\\/VIS multispectral data, at 340 m spatial resolution, in order to provide new insights into both optical\\/compositional heterogeneities and emplacement of the geological units within the

P. D. Martin; P. C. Pinet; S. D. Chervel

1997-01-01

47

Lunar soil characterization consortium analyses: Pyroxene and maturity estimates derived from Clementine image data  

Microsoft Academic Search

The mineralogy of a planetary surface is a diagnostic product of its formation and geologic evolution. Global assessment of lunar mineralogy at high spatial resolution has been a long standing goal of lunar exploration. Currently, the only global data available for such study is multispectral imagery from the Clementine mission. We use the detailed compositional, petrographic, and spectroscopic data of

Carle Pieters; Yuriy Shkuratov; Vadim Kaydash; Dmitriy Stankevich; Lawrence Taylor

2006-01-01

48

Multispectral Photometry of the Moon and Absolute Calibration of the Clementine UV\\/Vis Camera  

Microsoft Academic Search

We present a multispectral photometric study of the Moon between solar phase angles of 0 and 85°. Using Clementine images obtained between 0.4 and 1.0 ?m, we produce a comprehensive study of the lunar surface containing the following results: (1) empirical photometric functions for the spectral range and viewing and illumination geometries mentioned, (2) photometric modeling that derives the physical

John K. Hillier; Bonnie J. Buratti; Kathryn Hill

1999-01-01

49

Multispectral Photometry of the Moon and Absolute Calibration of the Clementine UV\\/Vis Camera  

Microsoft Academic Search

We present a multispectral photometric study of the Moon between solar phase angles of 0 and 85 deg. Using Clementine images obtained between 0.4 and 1.0 mum, we produce a comprehensive study of the lunar surface containing the following results: (1) empirical photometric functions for the spectral range and viewing and illumination geometries mentioned, (2) photometric modeling that derives the

John K. Hillier; Bonnie J. Buratti; Kathryn Hill

1999-01-01

50

The distribution of olivine in the crater Aristarchus inferred from Clementine NIR data  

Microsoft Academic Search

Clementine imaged the Moon entirely at eleven wavelengths. This paper presents new results obtained on the crater Aristarchus using a heuristic method for the calibration of the near infrared (NIR) data set. We computed band ratios and we extracted spectra using a telescopic spectrum as reference. A new ~4×10km olivine rich area has been identified on the southeastern rim of

Stéphane Le Mouélic; Yves Langevin; Stéphane Erard

1999-01-01

51

77 FR 63311 - Lake Clementine Hydro, LLC; Notice of Successive Preliminary Permit Application Accepted for...  

Federal Register 2010, 2011, 2012, 2013

...at the U.S. Corps of Engineer's North Fork Dam on the North Fork of the American River, near the City of Auburn, Placer County...that now flows over the spillway of the North Fork Dam, Lake Clementine Hydro plans to install two...

2012-10-16

52

75 FR 81942 - Importation of Clementines From Spain; Amendment to Inspection Provisions  

Federal Register 2010, 2011, 2012, 2013

...consignment of clementines is rejected. If a single Medfly is found in any two lots from the same orchard during the same shipping season, that orchard is removed from the export program for the remainder of the shipping season. A cutting and...

2010-12-29

53

Global Mapping of Mg-Number Derived from Clementine Data.  

NASA Astrophysics Data System (ADS)

The global mapping of the lunar surface using the petrological parameter Mg-number (Mg*) was undertaken because Mg*, or the ratio of Mg to the sum of Mg and Fe on an atomic basis, is an important disciminator in defining and understanding lunar rocks. The dominant lunar rock types, ferroan anorthosites (FAN), high-magnisium suite (HMS), and high-alkali suite (HAS) rocks all vary in Mg* depending upon the petrologic scenario that formed them. Of particular interest are FAN mineralogy and chemistry, which varies from high-Mg# (~70) troctolites to low-Mg# norites (~50) and for some time has been considered to represent a single magma frac-tionation trend. However, recent studies have also shown that the crystallization of FAN rocks may have been more complicated than originally thought. James et al. [1] found that instead of one simple fractionation trend for ferroan anorthosites, there may have been four. Studies by [2], [3], and [4] using Apollo and lunar meteorites for analysis have also eluded to the possibility that FAN rocks may have evolved from a more complex source or process. Therefore a global assessment of lithologies and corresponding Mg* is of great value for lunar petrology. In a remote sensing context, Mg* is the most important control on the spectral properties of lunar mafic silicates. For stoichiometric orthopyroxene and olivine, Mg* is mathematically linked to the Fe content that controls the overall reflectance and intensity of absorption. The changes in band centers and shape that accompany the structural changes as Fe substitutes for Mg along the solid solution series have long been recognized; these changes are highly correlated with Mg*. In clinopyroxene, the strong effect of Ca on structure makes this element important, but Mg* has the dominant effect on reflectance and a comparable effect on spectral shape. In this study, the lunar surface is quantitatively mapped using a theoretical treatment of mineralogic spectra and the effect of environmental space exposure on the optical properties of these minerals. This was accomplished using Clementine ultraviolet and visible (UVVIS) data and a Hapke radiative transfer mixing model. The major features evident in these maps are the strong distinction between mare and highland regions, the former showing low Mg* and the latter generally higher; a large northern highlands unit with low Mg*, and an Mg* high north of South Pole-Aitken basin. Mare units are not universally low, mare Frigoris in particular has elevated Mg* relative to other mare. The strongest variations in the highlands occur in plagioclase rich, low FeO units, that exhibit values ranging near 50 to near 100 in coherent units. The craters Tycho and Aristarchus also exhibit high Mg*; these gabbroic anomalies may indicate more extensive Mg-rich material at depth. Deposits within SPA are unremarkable relative to surroundings, and share the intermediate Mg* of most of the highlands. 1. James, O.B. et al. PLPSC. 1989.; 2.Bersch, M.G., et al., GRL, 1991.; 3. Floss, C., et al., GCA, 1998.; 4. Korotev, R.L., et al., GCA, 2003.

Cahill, J. T.; Lucey, P. G.; Gillis, J. J.; Steutel, D.

2004-12-01

54

Discrimination Between Maturity and Composition from Integrated Clementine UltraViolet-Visible and Near-Infrared Data  

Microsoft Academic Search

The Clementine UV-VIS dataset has greatly improved our understanding of the Moon. The UV-VIS camera was limited to five spectral channels from 415 to 1000 nm. The Clementine near-infrared (NIR) camera was designed to complement this spectral coverage. The NIR filter at 2000 run allows the discrimination between olivine and pyroxene within identified mare basalts. In addition, we will show

S. Le Mouelic; Y. Langevin; S. Erard; P. Pinet; Y. Daydou; S. Chevrel

1999-01-01

55

The Clementine Spacecraft A.L.P.O. LTP terrestrial mission  

Microsoft Academic Search

From 1994 Feb 28 - Apr 28, 28 A.L.P.O. observers monitored 35 selected lunar features, as well as others, in a program planned to coincide with imagery taken by the Clementine Spacecraft. Several lunar transient events were reported, including visual observations confirmed by other visual observers, as well as events recorded using spectroscopes, crater-extinction devices (CED), film photographs, and video.

W. S. Cameron; D. O. Darling; B. Manske; D. D. Weier

1997-01-01

56

Shelf-life and quality evaluation of clementine following a combined treatment with ?-irradiation  

NASA Astrophysics Data System (ADS)

In order to enhance the shelf-life of a late variety of Moroccan Citrus clementina (Nour), ionizing treatments were applied at 0.3kGy, as well as washing (cold water) and waxing treatments. It has been found that, despite the irradiation treatment, the washing and waxing treatment do not improve the quality of C. clementina, but rather result in peel injury. Finally, sensory evaluation confirmed that irradiation had no detrimental effect on the quality of clementines.

Mahrouz, M.; Lacroix, M.; D'Aprano, G.; Oufedjikh, H.; Boubekri, C.

2004-09-01

57

A Clementine Derived Control Network and Topographic Model - The Unified Lunar Control Network 2005  

Microsoft Academic Search

U. S. Geological Survey, Astrogeology Team, Flagstaff, AZ, United States Introduction: We have completed a new general unified lunar control network and lunar topographic model based on Clementine images. It includes the determination, in the lunar mean Earth\\/polar axis system, of the 3-D positions of 272,931 points on the lunar surface and the correction of the camera angles for 43,866

B. A. Archinal; M. R. Rosiek; R. L. Kirk; B. L. Redding

2006-01-01

58

A 70th degree lunar gravity model (GLGM-2) from Clementine and other tracking data  

Microsoft Academic Search

A spherical harmonic model of the lunar gravity field complete to degree and order 70 has been developed from S band Doppler tracking data from the C)ementine mission, as well as historical tracking data from Lunar Orbiters 1-5 and the Apollo 15 and 16 subsate)lites. The mode) combines 361,000 Doppler observations from Clementine with 347,000 historical observations. The historical data

Frank G. R. Lemoine; David E. Smith; Maria T. Zuber; Gregory A. Neumann; David D. Rowlands

1997-01-01

59

Microtextured metals for stray-light suppression in the Clementine startracker  

Microsoft Academic Search

Anodized blacks for suppressing stray light in optical systems can now be replaced by microscopically textured metal surfaces. An application of these black surfaces to the Clementine star-tracker navigational system, which will be launched in early 1994 to examine the Moon, en route to intercept an asteroid, is detailed. Rugged black surfaces with Lambertian BRDF less than 10(exp -2) srad(sup

E. A. Johnson

1993-01-01

60

Ricor K506B cryocooler performance during the Clementine mission and ground testing: A status report  

Microsoft Academic Search

Two Ricor K506B Stirling cycle cryocoolers with H-10 control electronics were used on the Clementine spacecraft, one cooling a 256 x 256 InSb infrared detector for the near-infrared (NIR) camera and the other cooling a 128 x 128 HgCdTe focal plane array on the longwave infrared (LWIR) camera. This is the first use of these Ricor Stirling cryocoolers in a

R. E. Priest; J. A. Robinson; T. L. Clark; D. R. Hadley; N. R. Sewall

1994-01-01

61

Ricor K506B cryocooler performance during the Clementine mission and ground testing  

Microsoft Academic Search

Two Ricor K506B Stirling cycle cryocoolers with H-10 control electronics were used on the Clementine spacecraft, one cooling a 256 x 256 InSb infrared detector for the near-infrared (NIR) camera and the other cooling a 128 x 128 HgCdTe focal plane array on the longwave infrared (LWIR) camera. This is the first use of these Ricor Stirling cryocoolers in a

Robert E. Priest; Jeffrey A. Robinson; Thomas L. Clark; Dean R. Hadley; Noel R. Sewall

1994-01-01

62

Approaches for sampling the twospotted spider mite (Acari: Tetranychidae) on clementines in Spain.  

PubMed

Tetranychus urticae Koch (Acari: Tetranychidae) is an important pest of clementine mandarins, Citrus reticulata Blanco, in Spain. As a first step toward the development of an integrated crop management program for clementines, dispersion patterns of T. urticae females were determined for different types of leaves and fruit. The study was carried out between 2001 and 2003 in different commercial clementine orchards in the provinces of Castelló and Tarragona (northeastern Spain). We found that symptomatic leaves (those exhibiting typical chlorotic spots) harbored 57.1% of the total mite counts. Furthermore, these leaves were representative of mite dynamics on other leaf types. Therefore, symptomatic leaves were selected as a sampling unit. Dispersion patterns generated by Taylor's power law demonstrated the occurrence of aggregated patterns of spatial distribution (b > 1.21) on both leaves and fruit. Based on these results, the incidence (proportion of infested samples) and mean density relationship were developed. We found that optimal binomial sample sizes for estimating low populations of T. urticae on leaves (up to 0.2 female per leaf) were very large. Therefore, enumerative sampling would be more reliable within this range of T. urticae densities. However, binomial sampling was the only valid method for estimating mite density on fruit. PMID:16937708

Martínez-Ferrer, M T; Jacas, J A; Ripollés-Moles, J L; Aucejo-Romero, S

2006-08-01

63

Fast reactor operation in the United States  

Microsoft Academic Search

Of the many American facilities dedicated to fast reactor technology, six qualify as liquid-metal-cooled fast reactors. All of these satisfy the following criteria: an unmoderated neutron spectrum, highly enriched fuel material, substantial heat production, and the use of a liquid metal coolant. These include the following: EBR-I Clementine, LAMPRE, EBR-II, EFFBR, and SEFOR. Collectively, these facilities encompassed all of the

R. R. Smith; D. W. Cissel

1978-01-01

64

The South pole region of the moon as seen by clementine.  

PubMed

The Clementine mission has provided the first comprehensive set of high-resolution images of the south pole region of the moon. Within 5 degrees of latitude of the pole, an area of an estimated 30,000 square kilometers remained in shadow during a full lunar rotation and is a promising target for future exploration for ice deposits. The Schrödinger Basin (320 kilometers in diameter), centered at 75 degrees S, is one of the two youngest, least modified, great multiring impact basins on the moon. A large maar-type volcano localized along a graben within the Schrödinger Basin probably erupted between 1 and 2 billion years ago. PMID:17737080

Shoemaker, E M; Robinson, M S; Eliason, E M

1994-12-16

65

Carbohydrate control over carotenoid build-up is conditional on fruit ontogeny in clementine fruits.  

PubMed

The final contents of primary and secondary metabolites of the ripe fruit depend on metabolic processes that are tightly regulated during fruit ontogeny. Carbohydrate supply during fruit development is known to influence these processes but, with respect to secondary metabolites, we do not really know whether this influence is direct or indirect. Here, we hypothesized that the sensitivity of clementine fruit metabolism to carbohydrate supply was conditional on fruit developmental stage. We applied treatments increasing fruit load reversibly or irreversibly at three key stages of clementine (Citrus clementina Hort. ex Tan.) fruit development: early after cell division, at the onset of fruit coloration (color break) and near maturity. The highest fruit load obtained by early defoliation (irreversible) had the highest impact on fruit growth, maturity and metabolism, followed by the highest fruit load obtained by early shading (reversible). Final fruit size decreased by 21 and 18% in these early irreversible and reversible treatments, respectively. Soluble sugars decreased by 18% in the early irreversible treatment, whereas organic acids increased by 46 and 29% in these early irreversible and reversible treatments, respectively. Interestingly, total carotenoids increased by 50 and 18%, respectively. Changes in leaf starch content and photosynthesis supported that these early treatments triggered a carbon starvation in the young fruits, with irreversible effects. Furthermore, our observations on the early treatments challenge the common view that carbohydrate supply influences positively carotenoid accumulation in fruits. We propose that early carbon starvation irreversibly promotes carotenoid accumulation. PMID:22882610

Poiroux-Gonord, Florine; Fanciullino, Anne-Laure; Poggi, Isabelle; Urban, Laurent

2012-09-13

66

A New Global Digital Map of the Moon from Clementine Image Data  

NASA Astrophysics Data System (ADS)

A new cartographic control net for the Moon has been completed utilizing Clementine image data. Previous geometric control for the Moon contained errors of _˜1-2 km on the near side and up to _˜10 km for the far side. Selection of over 265,000 match points from _˜43,000 images has improved the global accuracy to _˜250 m/pixel. Several automated procedures were developed to aid in finding matchpoints, with a success rate exceeding 90%. These new mosaicking techniques will be applicable to future planetary datasets and are included in the ISIS software package available at no cost through the Internet (http://wwwflag.wr.usgs.gov/USGSFlag/Data/software/isis.html). Matchpoints were processed at RAND for analytic triangulation. Absolute control was obtained by holding known locations (such as Apollo landing sites) as truth. Camera angles for each image were updated using a least squares fit to minimize offsets between matchpoints. The mean error for the entire Moon is less than 1 pixel. The final 1 km monochromatic basemap was constructed using 750 nm images except where gaps existed in the coverage; these gaps were filled using 900 nm images, empirically fit to match the brightness of the adjacent 750 nm data. The data have been normalized to a phase angle of 30deg using an improved photometric function derived from Clementine and Galileo image data. Work is currently underway processing the remaining bands covering the wavelength range of 415-2780 nm.

Becker, T. L.; Edwards, K. E.; Cook, D.; Eliason, E.; Lee, E. M.; McEwen, A. S.; Morgan, H.; Robinson, M. S.; Colvin, T.; Davies, M.; Duxbury, T.; Sorensen, T.

1996-09-01

67

Geology of the lunar regional dark mantle deposits as seen by Clementine UVVIS data  

NASA Astrophysics Data System (ADS)

We have used calibrated Clementine UVVIS data to map the geology and analyze spectra from several regional Dark Mantle Deposits (DMD) on the moon, including Taurus-Littrow (TL), Rima Bode (RB), Sulpicius Gallus (SG), Aristarchus Plateau (AP), and Orientale (OR). Regional DMD formed from pyroclastic eruptions and are composed of either volcanic glasses or crystallized beads. Unlike smaller localized dark mantle deposits, like those in Alphonsus and Franklin craters, which are only a few kms in diameter and are produced from vulcanian eruptions, regional DMD cover tens of km and indicate higher volume fluxes and plume heights. The crystallinity of the volcanic beads in a DMD is a very useful parameter for determining the cooling rates within the volcanic plume, with glasses indicating high cooling rates in a low optical density plume. Telescopic spectral data of the deposits indicate that TL and RB are dominated by crystallized black beads, SG is an equal mixture of glasses and black beads, while AP is dominated by the glasses. More recent Clementine data of the OR deposit on the lunar farside has shown that it is composed of volcanic glasses similar to those in the AP deposit.

Weitz, C. M.; Head, J. W., III; Pieters, C. M.

1997-03-01

68

The Aristarchus Plateau on the Moon: Mineralogical and structural study from integrated Clementine UV–Vis–NIR spectral data  

Microsoft Academic Search

Combining UVVIS and NIR Clementine spectral data, we characterize the mineralogy of the different volcanic and crustal materials occurring on the Aristarchus Plateau and its close vicinity, in order to investigate their stratigraphic relationships and understand the nature of the crust in this region of the Moon. From an iterative linear mixture modeling, we provide a comprehensive description of the

S. D. Chevrel; P. C. Pinet; Y. Daydou; S. Le Mouélic; Y. Langevin; F. Costard; S. Erard

2009-01-01

69

Ricor K506B cryocooler performance during the Clementine mission and ground testing: A status report  

SciTech Connect

Two Ricor K506B Stirling cycle cryocoolers with H-10 control electronics were used on the Clementine spacecraft, one cooling a 256 x 256 InSb infrared detector for the near-infrared (NIR) camera and the other cooling a 128 x 128 HgCdTe focal plane array on the longwave infrared (LWIR) camera. This is the first use of these Ricor Stirling cryocoolers in a space environment. This mission has demonstrated the use of these Clementine lightweight imaging sensors in the demanding environment of space, and has space-qualified this Ricor cryocooler. Moreover, nearly the entire 38 million square kilometers of the Moon`s surface was mapped in 11 spectral bands, six in the near-infrared, during the 71 days of lunar mapping. The more than 1.6 million digital images collected are providing-mineral typing scientific data to the international civilian scientific community. The NIR cryocooler operated successfully for a total of 840 hours with 361 on/off cycles. The H-10 electronics provided good focal plane array (FPA) temperature control with a typical operating FPA temperature of 70.3 K and a one-sigma variation of 0.46 K. The thermal environment for the cooler ranged from -23.7{degrees}C to 38.2{degrees}C. The Ricor cryocooler used on the LWIR camera performed the same during the Clementine mission as it did on the ground. This cryocooler ran for a total of 670 hours with 359 on/off cycles. The H-10 electronics were not able to provide FPA temperature control. This inability to operate at a fixed set point is believed to be caused by a ground difference between the H-10 controller electronics and the FPA temperature sense diode. The FPA temperature varied in proportion to the cryocooler (heat reject) temperature. The FPA temperature during imaging varied from 66.9 K to > 85 K. The thermal environment for this cooler ranged from -22.1{degrees}C to 41.0{degrees}C.

Priest, R.E.; Robinson, J.A.; Clark, T.L.; Hadley, D.R.; Sewall, N.R.

1994-09-01

70

Lunar Photometry from Clementine Multiangular Data: Analysis of Hapke Parameters Estimate and Implication for Upcoming Smart-1 Spot-Pointing Data  

NASA Astrophysics Data System (ADS)

We explore how well constrained is the determination of photometric function parameters using: 1) the widely used Hapke photometric model and 2) extensive set of spot-pointing observations provided by Clementine over the Reiner-Gamma region.

Kaydash, V. G.; Pinet, P. C.; Baratoux, D.; Besse, S.; Jehl, A.; Chevrel, S.

2006-03-01

71

Lunar surface geochemistry: Global concentrations of Th, K, and FeO as derived from lunar prospector and Clementine data  

Microsoft Academic Search

Accurate estimates of global concentrations of Th, K, and FeO have an important bearing on understanding the bulk chemistry and geologic evolution of the Moon. We present empirical ground-truth calibrations (transformations) for Lunar Prospector gamma-ray spectrometer data (K and Th) and a modified algorithm for deriving FeO concentrations from Clementine spectral reflectance data that incorporates an adjustment for TiO2 content.

Jeffrey J. Gillis; Bradley L. Jolliff; Randy L. Korotev

2004-01-01

72

Hot water, sodium carbonate, and sodium bicarbonate for the control of postharvest green and blue molds of clementine mandarins  

Microsoft Academic Search

Clementine mandarins cv. ‘Clemenules’, artificially inoculated with Penicillium digitatum or Penicillium italicum, were immersed in 0, 2, or 3% (w\\/v) sodium carbonate (SC) solutions at 20, 45 or 50°C for 60 or 150 s. Decay incidence was determined after 7 days of storage at 20°C and 90% relative humidity (RH). Hot water (HW) at 45 or 50°C did not satisfactorily

Llu??s Palou; Josep Usall; José A Muñoz; Joseph L Smilanick; Inmaculada Viñas

2002-01-01

73

A new data reduction approach for the Clementine NIR data set: Application to Aristillus, Aristarchus and Kepler  

Microsoft Academic Search

The Clementine spacecraft, launched in January 1994, has performed a nearly global surface mapping of the moon in eleven broad spectral bands at a resolution of ~200 m. The UV-visible (UV\\/VIS) camera performed observations in five bands ranging from 0.415 to 1.0 mum, while the near infrared camera (NIR) acquired data in six spectral bands ranging from 1.1 to 2.78

Stéphane Le Mouélic; Yves Langevin; Stéphane Erard

1999-01-01

74

Subpixel Detection of Pyroclastic Materials in Clementine Ultra Violet-Visible Data  

NASA Astrophysics Data System (ADS)

Lunar pyroclastic deposits represent a style of volcanism different from that responsible for the flood basalts that fill the mare basins. As volatile-coated, primitive materials originating deep (about 400 km) within the Moon, these products of explosive volcanic eruptions are also important as probes of mantle composition and as a potential resource for future settlers. While many of the lunar pyroclastic deposits are spatially restricted and relatively small in size, they are easily resolvable at the spatial scale (about 100 m/pixel) of the Clementine UV-VIS camera. Recent studies confirm previous results indicating that these deposits are not compositionally uniform, and suggest that further analyses can help to identify possible genetic relationships among lunar pyroclastic deposits, characterize their juvenile components, and clarify their relationships to nearby maria. Among the juvenile materials from sampled lunar pyroclastic deposits are the orange glass and devitrified black beads found in the Taurus-Littrow Valley and the green glass found by Apollo 15. Recent studies suggest that deposits dominated by materials such as these may represent end members in the observed compositional variations among the lunar pyroclastic deposits. Here we present preliminary results of analyses focused on the use of the Clementine UV-VIS data for characterizing the composition and distribution of juvenile pyroclastic materials. Our test case for detailed mapping of a lunar pyroclastic deposit is that of the Apollo 17 landing site in the Taurus-Littrow (TL) Valley. Although black beads dominate the observed spectral reflectance at this site, sample data show that the pyroclastic eruption changed character, producing first orange glass and then black beads. To assess the compositional variability of this deposit, especially our ability to distinguish the orange glasses, we apply techniques based on spectral mixture analysis to detect materials at subpixel scales. The low albedo and subdued absorption features of the Taurus-Littrow deposit make this a challenging task. In recent years, several subpixel detection techniques have been developed for use with terrestrial airborne imaging spectrometer data. A technique that is functionally equivalent to spectral mixture analysis, the orthogonal subspace projection (OSP) technique is used for the simulations presented here. In OSP, a target spectrum is projected onto a subspace that is orthogonal to a set of background spectra. In this process, the response from the background spectra are nulled and that of the target is maximized. For the TL site, the spectra used for the simulation included three laboratory-measured sample spectra convolved to the five UV/VIS bandpasses, and two spectra extracted from UV-VIS data over the TL Valley. The target spectrum was the orange soil sample 74220 from the Shorty Crater rim. "Background" spectra were from samples 74221 (a gray soil found near the orange soil) and 75111 (a dark mare soil). From the UV/VIS data, additional background spectra were obtained at the mare/highland interface and from the "crater cluster" area in the TL Valley. In the simulation, the background spectra were randomly mixed in each of 100 samples with 0.1% Gaussian noise added. For samples 20,40, 60, and 80, the orange soil target was added in abundances of 90, 80, 60, and 40%. The 100-sample set was then reduced via OSP. For this example, the orange soil was detectable only at the 90 and 80% abundance levels. It was found that the addition of higher noise levels (about 1%), made the orange glass undetectable even at the 90% level. However, using background materials more representative of the highlands made the orange soil detectable at lower abundances. These results suggest that we should be able to map the distribution of juvenile pyroclastic materials, such as the orange glasses, using the Clementine UV-VIS data and subpixel analysis techniques such as spectral mixture analysis and foreground background analysis. Given the low albedo of these materia

Farrand, W. H.; Gaddis, L. R.

1999-01-01

75

Is random noise causing a poor correlation between the Lunar Prospector TiO2 data and Clementine UVVIS-color ratio?  

NASA Astrophysics Data System (ADS)

The ability to measure TiO2 remotely is important for mapping the composition lunar basalt flows globally, and for placing lunar samples into a regional and global geologic context. Comparing Clementine UVVIS-ratio (415/750 nm) with Lunar Prospector derived TiO2 data, however, yields a less than ideal correlation, which would suggest that either the UVVIS ratio has poor predictive capabilities with respect to TiO2 composition or poor accuracy of the Lunar Prospector TiO2 data. Established uncertainties of the Clementine UVVIS data are approximately 1%, while the reported relative errors for Lunar Prospector neutron spectrometer data are on the order of 5%. Thus, we investigate the possibility of whether the greater uncertainty of the Lunar Prospector neutron data could cause the poor correlation between the two data sets. The sensitivity of the TiO2-UVVIS correlation to data accuracy was measured by adding randomly-distributed noise to the Clementine UVVIS data, and then comparing this modified Clementine data with the "noiseless" Clementine data. The comparison was then evaluated for the level of noise needed to produce a similar amount of scatter observed in the Lunar Prospector TiO2 and Clementine UVVIS-ratio trend. The results of this study indicate that Lunar Prospector would have to possess significantly more than 5% uncertainty to match the observed poor correlation between Lunar Prospector and Clementine data sets. On this basis, we concluded that algorithms that depend solely upon correlations between UV and visible spectral parameters and TiO2 concentration have inherently poor predicting power.

Gillis, Jeffrey J.; Lucey, Paul G.

2004-12-01

76

The Moon as a Spectral Calibration Standard Enabled by Lunar Samples: The Clementine Example  

NASA Astrophysics Data System (ADS)

Special calibration of Clementine data relies on the Apollo 16 site and laboratory measurements of mature soil 62231.The process produces calibrated spectra reflectance factors. What color is the Moon? A reflectance spectrum is essentially a measure of how much radiation incident on a surface (solar radiation) is reflected and how much is absorbed at each wavelength. To the eye the Moon is gray-white, but to photoelectric instruments it is various shades of red - that is, it exhibits an increase in brightness with wavelength. In the near-infrared there are absorptions diagnostic of minerals superimposed on the Moon's redness. For the Moon and other rocky bodies such as asteroids, most of the detectable absorptions arise from ferrous iron in various crystallographic sites. The wavelength, shape, and strength of these absorptions identify the minerals present, and allow their abundances to be estimated. Accurately measuring these diagnostic mineral absorptions with remote detectors requires not only a quality instrument, but also excellent electronic calibration and either direct measurement of the light source (the Sun) or a proxy, or a well-known reference standard illuminated by the same light source. In the laboratory a white reference such as halon (or commercial Spectralon), is used which in turn has been extensively calibrated relative to a known radiance. In space, or at the telescope, a separate reference must be found to mimic solar radiation and to eliminate instrumental and atmospheric effects. Radiation from stars to a first order follows a black body spectral curve with multiple emission and absorption lines superimposed. Because stellar lines vary with spectral type, and very few stars are really solar-like, it is actually quite difficult to use stars as spectral standards. The Moon is a nearby atmosphereless body that reflects solar radiation. Because the Moon's surface itself does not change with time (at least within our lifetimes), it provides an excellent reference standard. The calibration challenge then reduces to identifying an area on the Moon whose measurable properties are exceptionally well known. The return of lunar samples allows their properties to be measured accurately in Earth-based laboratories. Since the samples were collected from known areas on the surface of the Moon, carefully selected samples can be used to represent the properties of that area. For Clementine data, the Apollo 16 site was chosen as a calibration target because it is a relatively homogeneous area with no nearby units of a significantly different material. Since all remote data are acquired as bidirectional reflectance, we use i = 30 deg., e = 0 deg as the standard geometry. The calibration steps used and the assumptions made are discussed briefly below. Additional information is contained in original.

Pieters, C. M.

1999-01-01

77

Estimation of elemental abundances of the lunar regolith using clementine UVVIS+NIR data  

NASA Astrophysics Data System (ADS)

In this study we propose a regression model for the estimation of lunar elemental abundances from spectral features extracted from Clementine multispectral imagery in the visible and near-infrared domain. We extract a set of spectral features, including the continuum slope, the FWHM of the ferrous absorption trough near 1000 nm, and the wavelengths and relative depths of the absorption minima and inflection points present in the trough. As a “ground truth” for the elemental abundances we rely on the Lunar Prospector gamma ray spectrometer (LP GRS) data. With respect to the elemental abundances of the Apollo and Luna landing sites independently derived from returned samples, the best examined regression model is a second-order polynomial. The proposed regression-based approach allows an estimation of the elemental abundances of Ca, Al, Fe, Mg, and O at an accuracy of about 1 wt% and some tenths of a weight percent for Ti. We examine the influence of calibration of the Clementine UVVIS+NIR data and find that its effect on the results obtained with the regression approach is minor. Furthermore, we define a three-endmember model which allows the petrographic mapping of the lunar surface materials in terms of their Fe, Mg, and Al abundances. We examine the global distribution of Mg-rich rocks, the distribution of cryptomaria, and the occurrence of aluminous mare basalts in the Frigoris region. A possible regional compositional anomaly in northwestern Oceanus Procellarum is found, which corresponds to an extended area displaying spectral characteristics consistent with mare basalt containing significant amounts of olivine. On local scales, we examine in terms of our regression model the highland craters Proclus and Tycho, the compositionally anomalous central peaks of the craters Copernicus and Bullialdus, and the pyroclastic deposits on the floor of Alphonsus and on the northern rim of Petavius. As a general result, we show that the regression-based approach allows the detection of the main lunar terrain classes and rock types based on multispectral imagery in the visible and near-infrared domain.

Wöhler, Christian; Berezhnoy, Alexey; Evans, Richard

2011-01-01

78

Preliminary Analysis of the Absolute Cartographic Accuracy of the Clementine UVVIS Mosaics  

NASA Astrophysics Data System (ADS)

Our analysis reveals that the UVVIS basemap absolute cartographic accuracy may be in the range of +/-1 km to +/- 10 km locally. No absolute ground control points exist on the lunar farside making assessment of any lunar control network problematic. Bore sighted centers for Clementine UVVIS images derived from mission produced NAIF archived spacecraft position and orientation data were compared with image centers derived from the USGS/RAND photogrammetrically adjusted pointing (using an assumed lunar radius of 1737.4 km). Offsets are typically < 1 km within the USGS/RAND absolute control net region (enclosed within +/-40 deg E/W and N/S region on the nearside), worsening up to approximately 10 km in the vicinity of the 90W and 90E longitude lines (albeit smaller near the poles), and then reducing to <1 km towards the center of the farside. The USGS 750 nm basemap (upon which all other UVVIS and NIR mosaics are registered) shows several km discrepancies in absolute spatial position with respect to an earlier "Unified Control Net"; these differences are being measured and a comparison will be made with the mission produced NAIF archived position and pointing data. We propose that when the RAND control net was constructed from the Clementine images, the fact that a constant radius of the Moon was used, and that the images were relatively small (requiring approximately 140 thousand images to cover the Moon), may have resulted in poorly constrained fits in regions where no absolute control was available i.e the entire farside and the nearside beyond the absolute control area. Compounding this problem is the fact that the Moon exhibits +/- 8 km of relief on the farside thus resulting in +/-2% scale errors for a significant portion of the images that compose the basemap. The lack of control, and the scaling problems on the farside, must negatively affect the control network solution in complex ways due to the large number of uncontrolled frames. At this time a definitive resolution of the discrepancies is not possible. However, we can make progress by generating synthetic images of the Moon using the UVVIS mosaic and a planet-wide 1 km/pixel Digital Elevation Model and then compare these to large area lunar images taken from Earth or from spacecraft. Obtaining an accurate cartographic solution of the entire Moon is required before future sample return missions are attempted for the farside or nearside limb areas.

Cook, A. C.; Robinson, M. S.; Semenov, B.; Watters, T. R.

2002-12-01

79

Aristarchus plateau: structural and compositional study from integrated clementine uv-vis-nir spectral data.  

NASA Astrophysics Data System (ADS)

The Aristarchus Plateau is one of the most complex region on the Moon. It is an old rectangular elevated crustal block about 170x220 km, with its west and east borders approximately concentric to the Imbrium basin, surrounded by younger mare basalts of Oceanus Procellarum. The Plateau shows extensive dark mantling deposit (DMD) of pyroclastic origin, cratering (Aristarchus crater), and mare basalt flooding. This region is important to understand the nature of the lunar crust and its relation with the early volcanism. In this work we integrated UV-VIS-NIR (400-2000nm) Clementine spectral reflectance data. Lunar Prospector data are also used. A statistical analysis (PCA: principal component analysis) has been applied to the integrated dataset in order to evidence extreme spectral behaviors in the spectral population within the Plateau. This permits to determine spectral units in relation with different types of lunar materials. Then an iterative linear mixing modeling has been applied to the dataset, using endmembers spectra determined from the PCA analysis, in order to characterize the lithology and to map geological units. This mapping gives for each unit the degree of eventual mixing of the different types of materials at the subpixel scale. The analysis shows that eight endmembers taken in eight geological units are requested to give a comprehensive description of the distribution and amount of surface mixing of the units present within the Plateau and its immediate vicinity. The integration of the UV-VIS-NIR Clementine data and the method of analysis of the dataset permit to better characterize the composition (mafic components) of the different volcanic and crustal materials present within the Aristarchus Plateau and determine their stratigraphic relationships in order to better understand the chronology of the geologic events (tectonic, volcanic, cratering) in this region of the Moon. Results show that the regional stratigraphy is represented by deep anorthositic-rich materials overlain by pyroxene and olivine bearing crustal materials. A sequence of emplacement of the different geological units we have evidenced on the Plateau is proposed from the early emplacement of the Imbrium basin ejecta, the pyroclastic units and to the last stage of the mare basalt flooding, giving some insight on the nature of the pre-Imbrium crust and stages of volcanism in this region of the Moon.

Chevrel, S. D.; Pinet, P. C.; Daydou, Y.; Baratoux, D.; Le Mouelic, S.; Costard, F.

2003-04-01

80

REACTOR  

DOEpatents

A breeder reactor is described, including a mass of fissionable material that is less than critical with respect to unmoderated neutrons and greater than critical with respect to neutrons of average energies substantially greater than thermal, a coolant selected from sodium or sodium--potassium alloys, a control liquid selected from lead or lead--bismuth alloys, and means for varying the quantity of control liquid in the reactor. (AEC)

Szilard, L.

1963-09-10

81

The Mare Humorum region of the moon - New optical, compositional, and geological inferences from Clementine  

NASA Astrophysics Data System (ADS)

The present paper deals with a detailed assessment of the surface properties in the Mare Humorum region of the moon. Spectral investigations have been made by means of the processing and analysis of Clementine UV/VIS multispectral data, at 340 m spatial resolution, in order to provide new insights into both optical/compositional heterogeneities and emplacement of the geological units within the basin interior and vicinity. The spatial coverage of our image-cube (more than 2.6 million spectra) maps the western part of the basin, up to the longitude of Vitello E. An extended highland area is also mapped west of the basin, including the western portion of the mare-bounding ring. Spatially coherent spectral units have been identified with the application of a new methodology, consisting in a coupled approach of a principal component analysis and an iterative linear mixing modeling. Information on maturity, iron abundance, and titanium content (mare) is also considered for the selection of the successive endmembers combinations. The results of our preliminary analyses are presented below. We discuss the information derived from the abundance maps in relation with the previous interpretations of remotely-sensed data of the region and draw inferences that document the nature and origin of the spectrally identified materials.

Martin, P. D.; Pinet, P. C.; Chervel, S. D.

1997-03-01

82

REACTOR  

DOEpatents

A pressurized water reactor in which automatic control is achieved by varying the average density of the liquid moderator-cooiant is patented. Density is controlled by the temperature and power level of the reactor ftself. This control can be effected by the use of either plate, pellet, or tubular fuel elements. The fuel elements are disposed between upper and lower coolant plenum chambers and are designed to permit unrestricted coolant flow. The control chamber has an inlet opening communicating with the lower coolant plenum chamber and a restricted vapor vent communicating with the upper coolant plenum chamber. Thus, a variation in temperature of the fuel elements will cause a variation in the average moderator density in the chamber which directly affects the power level of the reactor.

Roman, W.G.

1961-06-27

83

Inventory of Multiring Basins on the Moon After the Clementine Mission  

NASA Astrophysics Data System (ADS)

Multi-ring basins (impact craters greater than 300 km in diameter, regardless of presently expressed morphology; [1, 2]) are of primary importance in the excavation and redistribution of crustal materials and serve as the loci for the accumulation of extruded lavas on the Moon. Understanding their distribution and configuration is important in order to reconstruct the basin-forming impact [2]. The Clementine mission has made the first global maps of the Moon, including altimetry from a laser ranging experiment [3, 4]. This map permits the characterization of long-wavelength topographic features of the lunar crust, including the most prominent and important features, multi-ring basins. We have now surveyed the entire Moon with laser altimetry data from Clementine and have inventoried the global basin population. Many of the most obscure and degraded basins are strikingly expressed in the topographic data. Basins such as Mendel-Rydberg, a nearly obliterated ancient basin (600 km diameter, 5 km deep) south of Orientale, displays nearly as much relief as the "pristine" Orientale basin (900 km diameter; 7 km depth) [5]. The Fecunditatis basin, an obscure quasi-circular feature south of Mare Crisium [3], displays considerable topographic prominence, including an average relief of about 5 km. However, not all of the ancient basins are so deep: the Mutus-Vlacq basin [3], south of Nectaris, is clearly visible in the altimetry [5], but is only 1 to 1.5 km deep. Other basins that appear very ill-defined in the altimetry, yet clearly are present as regional depressions include the Australe, Tranquillitatis, and Margims basins [3]. That both relatively deep and shallow basins exist on the Moon is not surprising; what is remarkable is that there is no correlation between basin depth and geologic age. Apparently, basin morphology is more dependent on local conditions (e.g., crustal thickness, lithospheric conditions at the time of impact) than age. Another unusual expression of topography for a basin is that of the degraded Lomonosov-Fleming basin [3,6]. This feature appears as a quasi-circular, smooth plateau of nearly constant elevation about 500 km across. Such an expression is likely caused by infilling of the basin with ancient mare basalts, covered by highland plains and reexposed as the ejecta of dark halo impact craters [7,8]. This interpretation is supported by the mafic signature of the plains in this region in the Clementine global color image [9] and the presense of elevated amounts of iron in the highland crust here [10]. The altimetry data also show many depressions that are likely to be previously unrecognized basins. For example, depressions near the crater Darwin (20 degrees S, 70 degrees W; basin about 300 km diameter), eastern Mare Frigoris (55 degrees N, 30 degrees W; basin about 700 km across), and east of Mare Humboldtianum (60 degrees N, 130 degrees E; basin about 400 km diameter) are probably degraded impact basins. To date, over 45 basins and their rings have been mapped on the Moon and the relief and volumes of the basins have been measured. Work continues on the analysis of this numerical data, which should give insight into the processes of basin formation and planetary evolution. References: [1] Wilhelms D. E. (1987) USGS Prof. Pap. 1348, 302 pp. [2] Spudis P. D. (1993) Geology of Multi-Ring Impact Basins, Cambridge Univ., 263 pp. [3] Nozette S. et al. (1994) Science, 266, 1835. [4] Zuber M. T. et al. (1994) Science, 266, 1839. [5] Spudis P. D. et al. (1994) Science, 266, 1848. [6] Wilhelms D. and El-Baz F. (1977) USGS Map I-948. [7] Schultz P. H. and Spudis P. D. (1979) Proc. LPSC 10th, 2899. [8] Schultz P. H. and Spudis P. D. (1982) Nature, 302, 233. [9] Lucey P. G. et al. (1994) Science, 266, 1855. [10] Lucey P. G. et al. (1995) Science, 268, 1150.

Spudis, P. D.

1995-09-01

84

REACTOR  

DOEpatents

The system conteraplates ohmically heating a gas to high temperatures such as are useful in thermonuclear reactors of the stellarator class. To this end the gas is ionized and an electric current is applied to the ionized gas ohmically to heat the gas while the ionized gas is confined to a central portion of a reaction chamber. Additionally, means are provided for pumping impurities from the gas and for further heating the gas. (AEC)

Spitzer, L. Jr.

1962-01-01

85

Bistatic radar observations of the moon using the Clementine spacecraft and Deep Space Network  

NASA Astrophysics Data System (ADS)

The author prepared, executed, and analyzed the data from a series of spotlight-mode bistatic radar (BSR) observations of the Moon's North and South Poles. The Ballistic Missile Defense Organization Clementine spacecraft served as an S-band transmitter, and 70-m antennas of the NASA/Deep Space Network received the reflections. An average value of circular polarization ratio (CPR) for both poles of 0.344 (<0.031 standard deviation) was found, but varied between 0.20 to 0.6 over small regions. The North Pole average CPR was 0.359 (<0.0308 standard deviation). The South Pole average CPR was 0.333 (<0.0238 standard deviation). By analyzing the CPR response versus bistatic angle, the author discovered a slight CPR enhancement approaching 1 dB (0.11 dB standard deviation) for Orbit 234 of the South Pole. This CPR enhancement could result from the coherent backscatter opposition effect (CBOE). Radar observable CBOE would be consistent with radar scattering from theoretically predicted, but never observed, ice accumulations. The beta-zero BSR track and CPR enhancement correlate with areas of permanent shadow within the South Pole-Aitken Basin and with high hydrogen accumulations reported by Lunar Prospector. The author found that BSR beta-zero radar tracks through periodically solar illuminated areas yielded no enhancements in his data. The effect of angle of incidence on CPR for the South Pole was considered, and Orbit 234 was found to have a slightly elevated CPR compared to the other orbits. Previous radar observations of the Moon employed earth- based monostatic radars or rudimentary orbiting bistatic techniques. These methods only used the quasi-specular (QS) reflection component of scattering. This work is the first successful experiment to (a)collect data from lunar bistatic radar scattering using other than the dominant QS component, (b)use spotlight-mode bistatic radar technique outside of earth, and (c)return useful S-band bistatic scattering data from lunar polar regions, and (d)claim to detect slight radar enhancement for the South Pole using bistatic radar. Previous radar studies reached inconclusive or negative results regarding ice [Stacy, 1993, Stacy, et al., 1997; Simpson et al., 1999]. Simpson found ``weak suggestions of enhanced echoes at the time of South Pole backscatter'' [Simpson et al., 1999], while Stacy found high reflectivity and high CPR (>1) areas near the pole [Stacy, 1993, Stacy, et al., 1997]. Simpson and Stacy chose to attribute their observed enhancements to diffuse scattering, but allow that ice scattering might exist.

Lichtenberg, Christopher L.

2000-09-01

86

Distinguishing high-alumina mare basalts using Clementine UVVIS and Lunar Prospector GRS data: Mare Moscoviense and Mare Nectaris  

NASA Astrophysics Data System (ADS)

High-alumina (HA) mare basalts are a unique group of the lunar sample collection. Sample geochemistry indicates that these basalts are derived from sources composed of late-stage cumulates from the Lunar Magma Ocean (LMO). Their aluminous nature suggests their sources contained significant plagioclase, which has implications regarding the efficiency of plagioclase separation from earlier forming, mafic cumulates in the LMO to form the anorthositic lunar crust, and hence the heterogeneity of the lunar mantle. The Apollo and Luna missions sampled HA basalts from four different locations that are separated by 80 equatorial degrees (~2400 km). Radiometric age dating of these samples demonstrates aluminous basaltic volcanism spanned over 1 billion years, suggesting HA basalts may be more prevalent on the Moon than implied by the sample population. Knowing their global occurrence would ultimately enhance our understanding of lunar evolution. Aluminous mare basalts occupy a unique location in Th-FeO compositional space that suggests they can be identified using global remote-sensing data of the Moon. We present our approach for distinguishing exposures of HA basalts using Clementine ultraviolet-visible-infrared (UVVIS) and Lunar Prospector Gamma Ray Spectrometer (LP-GRS) data with constraints based on the FeO, TiO2, and Th abundances of Apollo and Luna HA samples. We identified 34 regions of interest (ROIs) where HA basalts could be a prominent component of the lunar surface. By analyzing the rims and proximal ejecta from small impacts (0.4-4 km in diameter) into the mare surface we characterized compositionally distinct basaltic units that make up the mare and thus determined which units represent HA basalt lavas. The results were used to generate maps that depict discrete mare units and classify their general basalt type. Here we focus on two ROIs: Mare Moscoviense and Mare Nectaris. Mare Moscoviense is composed of four basaltic units, two of which are HA candidates. Clementine UVVIS data of Mare Nectaris show evidence of up to three mare basalt units. One is the remnants of a mid-Ti unit that capped earlier low-Ti flows. The majority of the basin is filled by a compositionally indistinguishable low-Fe, low-Ti basalt. However, spectral profiles suggest there are two units. Regardless, the units both fit the criteria for a HA basalt.

Kramer, Georgiana Y.; Jolliff, Bradley L.; Neal, Clive R.

2008-01-01

87

Physiological and molecular analysis of the maturation process in fruits of Clementine Mandarin and one of its late-ripening mutants.  

PubMed

Peel color is one of the main features affecting citrus quality. Clementine is a widespread citrus species with several mutants showing a delay in pigmentation and harvesting. This work characterizes the fruit development and ripening of two clementine clones, 'Comune', a widespread variety, and one of its natural mutations, 'Tardivo', which differ by a delayed color-break and extended harvest period. Morphological, chemical, and molecular analyses were carried out on fruits of both genotypes during the whole maturation process. Analysis showed that mutation did not affect ripening characteristics such as juice acidity and TSS. However, biochemical and molecular analysis revealed marked differences in the flavedo regarding carotenogenesis and chlorophyllase gene expression. Carotenoid showed quantitative differences at biochemical and molecular levels. Results demonstrated that the mutation in 'Tardivo' influenced the transcriptional activation of PSY, a key step in carotenoid biosynthesis. The differential PSY expression led to a significant quantitative difference in phytoene accumulation between the two genotypes. Also, 'Tardivo' showed delayed accumulation of carotenes, lutein, and beta,beta-xanthophylls. The differential expression of genes involved in ethylene biosynthesis and perception suggested differing responses to ethylene signaling between the two genotypes. Moreover, exogenous application of ethylene revealed a different sensitivity of the two varieties to this hormone. The analysis added new information to better understand the complex process of ripening in citrus. PMID:19655798

Distefano, Gaetano; Las Casas, Giuseppina; Caruso, Marco; Todaro, Aldo; Rapisarda, Paolo; La Malfa, Stefano; Gentile, Alessandra; Tribulato, Eugenio

2009-09-01

88

Surface mineralogy and stratigraphy of the lunar South Pole-Aitken basin determined from Clementine UV/VIS and NIR data  

NASA Astrophysics Data System (ADS)

The South Pole-Aitken (SPA) basin, located on the lunar far side, is one of the oldest and largest recognised impact structures in the solar system. The basin is a proposed site for future sample return missions and human bases due to the unique geological environment and its potential for preservation of water ice in areas of near-permanent shadow. Here, we report surface mineralogy maps of the central and northern parts of the SPA basin, based on Clementine UV/VIS and NIR spectral data. Clementine LIDAR data and SMART-1 AMIE images provide additional geomorphological and stratigraphic information. A noritic mineralogical composition is identified as the deepest stratigraphic unit exposed on the basin floor. Norite is found in nearly all central peaks and in large topographical structures that have punched through an upper, often basaltic or gabbroic layer, including the Leibnitz and Apollo sub-basins. The thin layer of gabbroic/basaltic composition is distributed over large parts of the SPA basin floor and presumably overlays the noritic basement of apparent lower-crustal origin. Our data do not confirm the presence of olivine-rich material in the SPA basin, including at Olivine Hill, suggesting the mantle material was not excavated during the basin-forming impact.

Borst, A. M.; Foing, B. H.; Davies, G. R.; van Westrenen, W.

2012-08-01

89

Calculating iron contents of lunar highland materials surrounding Tycho crater from integrated Clementine UV-visible and near-infrared data  

NASA Astrophysics Data System (ADS)

Optical properties of lunar surface materials are modified by exposure to the space environment, including bombardment by solar wind particles and micrometeorites. One of the main problems in the interpretation of lunar spectral observations is to separate the effects of exposure (``space weathering'') and those due to the composition of the soils (mainly iron and titanium content). Here we use Clementine near-infrared (NIR) data to investigate this problem for highland-type soils in the Tycho crater area. Our approach is based on the methods developed for an analysis of a mare region near Aristarchus Plateau [Le Mouélic et al., 2000]. We show that the systematic relationships between spectral parameters (1-?m band depth and continuum slope), which were previously observed in a mare area with varying maturity degree, are also valid for highland-type soils. This technique aimed at evaluating the iron content of the surface materials from Clementine UV-visible (UVVIS) and near-infrared data can therefore be applied globally. This approach complements the widely used method of Lucey and coworkers, which relies on the UV-visible bands only. The proposed method relies mostly on band ratios. The iron map produced from this method is therefore less dependent on topography than the iron estimates obtained with UV-visible data alone, where brightness is one of the controlling parameters. Therefore the proposed approach should be particularly useful at middle to high latitudes, where local topography generates large variations in brightness and therefore hampers the interpretation of iron maps produced from UV-visible bands only.

Le Mouélic, Stéphane; Lucey, P. G.; Langevin, Yves; Hawke, B. Ray

2002-10-01

90

Composition and exposure age of the Apollo 16 Cayley and Descartes regions from Clementine data: Normalizing the optical effects of space weathering  

NASA Astrophysics Data System (ADS)

In order to quantitatively assess the composition of the lunar surface from reflectance spectroscopy, it is necessary to be able to differentiate between the optical effects due to composition and those due to exposure to space weathering processes. Laboratory analyses of returned lunar soils are used to show that limited quantitative compositional information and the exposure age of the lunar surface can be determined using straightforward calculations from remotely acquired reflectance data sampled with a small number of spectral channels. Exposure age, approximated by Is/FeO (where Is is the characteristic ferromagnetic signal from single-domain iron metal), is estimated using a ratio of the reflectance at a wavelength outside of the 1-?m ferrous iron absorption band to the reflectance at a wavelength within the band. The iron plus titanium content of a soil can then be calculated from its Is/FeO and reflectance. These combined techniques are applied to Clementine UVVIS multispectral data of the lunar highlands in the vicinity of the Apollo 16 landing site. The Is/FeO and FeO+TiO2 contents are calculated for this region. Materials associated with recently formed impact craters and recent and/or ongoing downslope movement are easily detected as nonmature. The FeO+TiO2 content of the Descartes Mountains is found to be 1-2 wt% less than the Cayley plains west of the Apollo 16 landing site. Localized areas of compositional heterogeneity associated with some small impact events are also revealed. A model for normalizing the optical contribution due to exposure to space weathering processes is applied to the Clementine UVVIS data in order to bring the data to an equivalent mature exposure state. This approach allows residual spectral differences between the observed materials to be confidently interpreted as being due to compositional differences alone rather than to differences both of composition and of exposure. The exposure-normalized data reveal that this region of the highlands is characterized by limited large-scale compositional heterogeneity that is detectable by a small number of spectral bandpasses. The Descartes Mountains are identified as being more anorthositic than the Cayley plains units. Most small impacts in the region excavated material compositionally similar to material surrounding them, with the notable exceptions of the impacts that created South Ray Crater and an unnamed crater on the floor of Abulfeda.

Fischer, Erich M.; Pieters, Carlé M.

91

Local and regional lunar regolith characteristics at Reiner Gamma Formation: Optical and spectroscopic properties from Clementine and Earth-based data  

NASA Astrophysics Data System (ADS)

A detailed remote sensing survey of the Reiner Gamma Formation (RGF) region by means of Earth-based telescopic and Clementine multispectral imaging has been made in the UV-visible-near-infrared domain. The spectral mixture analysis reveals the existence of three basic end-members relevant for modeling the observed spectral variations in the RGF vicinity. These are MB (mare background), SWS (southwest swirl), and RGS (Reiner Gamma soil). The first two components exhibit spectral characteristics consistent with a prevailing contribution of mature mare soils for the surroundings (MB) and of immature mare crater-like soils (RGS) at RGF. The third intermediate-albedo component (SWS) has general characteristics of a mature mare soil, but with a redder continuum slope. The reported observation can be modeled by a mechanism which would remove the finest fraction in the soil (particle diameter<45?m) at RGF and redistribute it in the vicinity with a laterally variable proportion and local accumulations such as at SWS site. According to the available set of in situ data documenting variations in the chemical composition, in the distribution of particle sizes, and in the degree of maturity with depth in the mare regolith, the characteristics depicted at RGF are those of a subsurface soil layer from a depth of the order of 0.3-0.8 m. In our view, the simplest way to account for the whole body of information available from the present work lies in the proposition that in the area of RGF the uppermost layer of the regolith has been optically and mechanically modified by a process involving the fall of fragments of a low-density cometary nucleus previously disrupted by tidal interaction in the Earth-Moon system. We recognize, however, that in the present state of knowledge, one cannot rule out the hypothesized existence of a zone of seismically modified terrain peripheral to the Imbrium or Orientale basins just beneath the mare surface that would be the actual source of the RGF magnetic anomaly.

Pinet, Patrick C.; Shevchenko, Vladislav V.; Chevrel, Serge D.; Daydou, Yves; Rosemberg, Christine

2000-04-01

92

New Algorithm for Mapping TiO2 Concentrations Using Clementine UVVIS Data Suggests a Non-uniform Global Distribution of Basalt Types.  

NASA Astrophysics Data System (ADS)

In both sample and remote sensing analysis of mare basalts, TiO2 is the most useful discriminator in classification because of its substantial variation in concentration, from <1 to >14wt.%. A significant discrepancy arises when comparing mare basalt sample data, which shows a bimodal distribution of TiO2 (modes at 2.5 and 12.5wt.%), with the remote sensing data, which shows a continuum (mode 2.75wt.%). It is thus important to map TiO2 accurately in order to understand whether basalts of intermediate-Ti content exist as abundantly as observed in the remote sensing data, and to determine their mode of origin (e.g., impact mixing of high and low-Ti units or derivation from intermediate-Ti source regions). Building upon earlier methods for estimating TiO2, we integrate basaltic rock and soil TiO2 concentrations with Clementine Spectral Reflectance (CSR) data to produce a more accurate algorithm for estimating TiO2. Two checks are used to test the accuracy of the modified algorithm. First, applying the algorithm to CSR data of 2x2 km regions centered on individual landing sites, we find that the algorithm faithfully reproduces the bimodal distribution of TiO2 contents as seen in the sample collection. Second, the Lunar Prospector neutron spectrometer data provide an independent test of the global estimates of TiO2 concentrations. When TiO2 concentrations from the new algorithm are coupled with the effects of other thermal neutron absorbers (e.g., Fe, Ca, Sm, Gd), they match more closely the observed epithermal-to-thermal neutron flux ratio than do the TiO2 concentrations calculated previously. Examining the global distribution of TiO2, we find that a majority of basalt flows with intermediate TiO2 concentrations occur in the western nearside maria with a minor distribution of intermediate TiO2 basalts occurring in the eastern maria. The intermediate-Ti basalts in M. Tranquillitatis appear to be caused by impact mixing between high and low-Ti basalts, whereas the basalt flows in O. Procellarum appear to have inherent intermediate-Ti contents. The heterogeneity in TiO2 between the eastern and western nearside maria suggests that mantle source regions below these areas differ significantly and that differences in mantle composition may be coupled to the crustal terranes under which they occur.

Gillis, J. J.; Jolliff, B. L.

2001-05-01

93

Stellar and Solar Positions in 1701-1703 Observed by Francesco Bianchini at the Clementine Meridian Line in the Basilica of Santa Maria degli Angeli in Rome, and its Calibration Curve  

NASA Astrophysics Data System (ADS)

Stellar aberration is the largest special relativistic effect discovered in astronomy (in 1727 by James Bradley), involving the speed of light when composed with Earth orbital motion. This effect with nutation affected the measurement of latitude with Polaris uppper and lower transits in the first week of January, 1701 made by Francesco Bianchini (1662-1729). Equinoxes and Solstices of 1703 were measured by timing solar and stellar transits at the Meridian Line of Pope Clement XI built in the Basilica of S. Maria degli Angeli in Rome. Original Eastward 4' 28.8" ± 0.6" deviation of the Line affects all measurements. The calibration curve of Clementine Line -here firstly published after 2 years of measurements- includes also local deviations of the Line, and it is used to correct solar and lunar ephemerides at 0.3 s level of accuracy, when meridian transits are there observed and timed.

Sigismondi, Costantino

2008-09-01

94

NEUTRONIC REACTOR  

DOEpatents

Means are presenied for increasing the reproduction ratio of a gaphite- moderated neutronic reactor by diminishing the neutron loss due to absorption or capture by gaseous impurities within the reactor. This means comprised of a fluid-tight casing or envelope completely enclosing the reactor and provided with a valve through which the casing, and thereby the reactor, may be evacuated of atmospheric air.

Fermi, E.; Zinn, W.H.; Anderson, H.L.

1958-09-16

95

NUCLEAR REACTOR  

DOEpatents

A boiling-water nuclear reactor is described wherein control is effected by varying the moderator-to-fuel ratio in the reactor core. This is accomplished by providing control tubes containing a liquid control moderator in the reactor core and providing means for varying the amount of control moderatcr within the control tubes.

Treshow, M.

1961-09-01

96

REACTOR COOLING  

DOEpatents

A nuclear reactor with provisions for selectively cooling the fuel elements is described. The reactor has a plurality of tubes extending throughout. Cylindrical fuel elements are disposed within the tubes and the coolant flows through the tubes and around the fuel elements. The fuel elements within the central portion of the reactor are provided with roughened surfaces of material. The fuel elements in the end portions of the tubes within the reactor are provlded with low conduction jackets and the fuel elements in the region between the central portion and the end portions are provided with smooth surfaces of high heat conduction material.

Quackenbush, C.F.

1959-09-29

97

NEUTRONIC REACTOR  

DOEpatents

BS>A nuclear reactor incorporating fuel rods passing through a moderator and including tubes of a material of higher Thermal conductivity than the fuel in contact with the fuel is described. The tubes extend beyond the active portion of the reactor into contant with a fiuld coolant.

Metcalf, H.E.; Johnson, H.W.

1961-04-01

98

Space reactors  

Microsoft Academic Search

Progress in technology development for the Space Power Advanced Reactor (SPAR) project is reported. The weights of neutron and gamma shields required to protect the SPAR system payloads for a range of permissible exposures was determined, and initial results are reported. SPAR reactor safety in the case of water immersion was modeled. Approval in principle was received for the SPAR

W. A. Ranken

1982-01-01

99

NEUTRONIC REACTOR  

DOEpatents

A nuclear reactor for isotope production is described. This reactor is designed to provide a maximum thermal neutron flux in a region adjacent to the periphery of the reactor rather than in the center of the reactor. The core of the reactor is generally centrally located with respect tn a surrounding first reflector, constructed of beryllium. The beryllium reflector is surrounded by a second reflector, constructed of graphite, which, in tune, is surrounded by a conventional thermal shield. Water is circulated through the core and the reflector and functions both as a moderator and a coolant. In order to produce a greatsr maximum thermal neutron flux adjacent to the periphery of the reactor rather than in the core, the reactor is designed so tbat the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the materials in the reflector is approximately twice the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the material of the core of the reactor.

Wigner, E.P.

1958-04-22

100

NUCLEAR REACTOR  

DOEpatents

A heterogeneous, natural uranium fueled, solid moderated, gas cooled reactor is described, in which the fuel elements are in the form of elongated rods and are dlsposed within vertical coolant channels ln the moderator symmetrically arranged as a regular lattice in groups. This reactor employs control rods which operate in vertical channels in the moderator so that each control rod is centered in one of the fuel element groups. The reactor is enclosed in a pressure vessel which ls provided with access holes at the top to facilitate loading and unloadlng of the fuel elements, control rods and control rod driving devices.

Moore, R.V.; Bowen, J.H.; Dent, K.H.

1958-12-01

101

NEUTRONIC REACTORS  

DOEpatents

A nuclear reactor is described wherein horizontal rods of thermal- neutron-fissionable material are disposed in a body of heavy water and extend through and are supported by spaced parallel walls of graphite.

Wigner, E.P.

1960-11-22

102

NEUTRONIC REACTOR  

DOEpatents

A nuclear reactor is described comprising fissionable material dispersed in graphite blocks, helium filling the voids of the blocks and the spaces therebetween, and means other than the helium in thermal conductive contact with the graphite for removing heat.

Anderson, H.L.

1960-09-20

103

NUCLEAR REACTOR  

DOEpatents

This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

Miller, H.I.; Smith, R.C.

1958-01-21

104

Space reactors  

Microsoft Academic Search

Progress in design studies and technology for the SP-100 Project - successor to the Space Power Advanced Reactor (SPAR) Project - is reported for the period October 1, 1981 to March 31, 1982. The basis for selecting a high-temperature, UO2-fueled, heat-pipe-cooled reactor with a thermoelectric conversion system as the 100\\/kW-sub e\\/ reference design has been reviewed. Although no change has

W. A. Ranken

1983-01-01

105

NUCLEAR REACTOR  

DOEpatents

A fluidized bed nuclear reactor and a method of operating such a reactor are described. In the design means are provided for flowing a liquid moderator upwardly through the center of a bed of pellets of a nentron-fissionable material at such a rate as to obtain particulate fluidization while constraining the lower pontion of the bed into a conical shape. A smooth circulation of particles rising in the center and falling at the outside of the bed is thereby established. (AEC)

Anderson, C.R.

1962-07-24

106

Research reactors - an overview  

SciTech Connect

A broad overview of different types of research and type reactors is provided in this paper. Reactor designs and operating conditions are briefly described for four reactors. The reactor types described include swimming pool reactors, the High Flux Isotope Reactor, the Mark I TRIGA reactor, and the Advanced Neutron Source reactor. Emphasis in the descriptions is placed on safety-related features of the reactors. 7 refs., 7 figs., 2 tabs.

West, C.D.

1997-03-01

107

NEUTRONIC REACTOR  

DOEpatents

This patent relates to neutronic reactors of the heterogeneous water cooled type, and in particular to a fuel element charging and discharging means therefor. In the embodiment illustrated the reactor contains horizontal, parallel coolant tubes in which the fuel elements are disposed. A loading cart containing a magnzine for holding a plurality of fuel elements operates along the face of the reactor at the inlet ends of the coolant tubes. The loading cart is equipped with a ram device for feeding fuel elements from the magazine through the inlot ends of the coolant tubes. Operating along the face adjacent the discharge ends of the tubes there is provided another cart means adapted to receive irradiated fuel elements as they are forced out of the discharge ends of the coolant tubes by the incoming new fuel elements. This cart is equipped with a tank coataining a coolant, such as water, into which the fuel elements fall, and a hydraulically operated plunger to hold the end of the fuel element being discharged. This inveation provides an apparatus whereby the fuel elements may be loaded into the reactor, irradiated therein, and unloaded from the reactor without stopping the fiow of the coolant and without danger to the operating personnel.

Ohlinger, L.A.; Wigner, E.P.; Weinberg, A.M.; Young, G.J.

1958-09-01

108

NUCLEAR REACTOR  

DOEpatents

A nuclear reactor of the homogeneous liquid fuel type is described wherein the fissionable isotope is suspended or dissolved in a liquid moderator such as water. The reactor core is comprised essentially of a spherical vessel for containing the reactive composition surrounded by a reflector, preferably of beryllium oxide. The reactive composition may be an ordinary water solution of a soluble salt of uranium, the quantity of fissionable isotope in solution being sufficient to provide a critical mass in the vessel. The liquid fuel is stored in a tank of non-crtttcal geometry below the reactor vessel and outside of the reflector and is passed from the tank to the vessel through a pipe connecting the two by air pressure means. Neutron absorbing control and safety rods are operated within slots in the reflector adjacent to the vessel.

Christy, R.F.

1958-07-15

109

POWER REACTOR  

DOEpatents

A fast nuclear reactor system ls described for producing power and radioactive isotopes. The reactor core is of the heterogeneous, fluid sealed type comprised of vertically arranged elongated tubular fuel elements having vertical coolant passages. The active portion is surrounded by a neutron reflector and a shield. The system includes pumps and heat exchangers for the primary and secondary coolant circuits. The core, primary coolant pump and primary heat exchanger are disposed within an irapenforate tank which is filled with the primary coolant, in this case a liquid metal such as Na or NaK, to completely submerge these elements. The tank is completely surrounded by a thick walled concrete shield. This reactor system utilizes enriched uranium or plutonium as the fissionable material, uranium or thorium as a diluent and thorium or uranium containing less than 0 7% of the U/sup 235/ isotope as a fertile material.

Zinn, W.H.

1958-07-01

110

NEUTRONIC REACTOR  

DOEpatents

A reactor of the type which preferably uses plutonium as the fuel and a liquid moderator, preferably ordinary water, and which produces steam within the reactor core due to the heat of the chain reaction is described. In the reactor shown the fuel elements are essentially in the form of trays and are ventically stacked in spaced relationship. The water moderator is continuously supplied to the trays to maintain a constant level on the upper surfaces of the fuel element as it is continually evaporated by the heat. The steam passes out through the spaces between the fuel elements and is drawn off at the top of the core. The fuel elements are clad in aluminum to prevent deterioration thereof with consequent contamimation of the water.

Metcalf, H.E.

1957-10-01

111

NEUTRONIC REACTORS  

DOEpatents

A method is presented for loading and unloading rod type fuel elements of a neutronic reactor of the heterogeneous, solld moderator, liquid cooled type. In the embodiment illustrated, the fuel rods are disposed in vertical coolant channels in the reactor core. The fuel rods are loaded and unloaded through the upper openings of the channels which are immersed in the coolant liquid, such as water. Unloading is accomplished by means of a coffer dam assembly having an outer sleeve which is placed in sealing relation around the upper opening. A radiation shield sleeve is disposed in and reciprocable through the coffer dam sleeve. A fuel rod engaging member operates through the axial bore in the radiation shield sleeve to withdraw the fuel rod from its position in the reactor coolant channel into the shield, the shield snd rod then being removed. Loading is accomplished in the reverse procedure.

Wigner, E.P.; Young, G.J.

1958-10-14

112

Bioconversion reactor  

DOEpatents

A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

McCarty, Perry L. (Stanford, CA); Bachmann, Andre (Palo Alto, CA)

1992-01-01

113

(Reactor dosimetry)  

SciTech Connect

The lead in most aspects of research reactor design and use passed from the USA about 15 years ago, soon after the construction of the HFIR and HFBR. The Europeans have consistently upgraded and improved their existing facilities and have built new ones including the HFR at Grenoble and ORPHEE at Saclay. They studied ultra-high flux concepts ({approximately}10{sup 20}/m{sup {minus}2}{center dot}s{sup {minus}1}) about 10 years ago, and are in the design phase of a new, highly efficient medium flux reactor to be built at Garching, near Munich in Germany. A visit was made to Interatom, the firm -- the equivalent of the Architect/Engineer for the ANS project -- responsible, under contract to the Technical University of Munich, for the new Munich reactor design. There are many similarities to the ANS design, and we reviewed and discussed technical and safety aspects of the two reactors. A request was made for some new, hitherto proprietary, experimental data on reactor thermal hydraulics and cooling that will be very valuable to the ANS project. I presented a seminar on the ANS project. A visit was made to Kernforschungszentrum Karlsruhe and knowledge was gained from Dr. Kuchle, a true pioneer of ultra-high flux reactor concepts, of their work. Dr. Kuchle kindly reviewed the ANS reference core and cooling system design (with favorable conclusions). I then talked with researchers working on materials irradiation damage and activation of structural materials by neutron irradiation, both key issues for the ANS. I was shown some new techniques they have developed for testing materials irradiation effects at high fluences, in a short time, using accelerated particle beams.

West, C.D.

1990-09-13

114

NEUTRONIC REACTOR  

DOEpatents

A nuclear reactor which uses uranium in the form of elongated tubes as fuel elements and liquid as a coolant is described. Elongated tubular uranium bodies are vertically disposed in an efficient neutron slowing agent, such as graphite, for example, to form a lattice structure which is disposed between upper and lower coolant tanks. Fluid coolant tubes extend through the uranium bodies and communicate with the upper and lower tanks and serve to convey the coolant through the uranium body. The reactor is also provided with means for circulating the cooling fluid through the coolant tanks and coolant tubes, suitable neutron and gnmma ray shields, and control means.

Wigner, E.P.; Weinberg, A.W.; Young, G.J.

1958-04-15

115

Neutronic reactor  

DOEpatents

A graphite-moderated nuclear reactor includes channels between blocks of graphite and also includes spacer blocks between adjacent channeled blocks with an axis of extension normal to that of the axis of elongation of the channeled blocks to minimize changes in the physical properties of the graphite as a result of prolonged neutron bombardment.

Carleton, John T. (Elsmere, DE)

1977-01-25

116

NUCLEAR REACTORS  

Microsoft Academic Search

A boiling reactor of the liquid-moderated, calandria type is designed in ; which the steam voidage in the core is constant, thereby giving a constant power ; level. In the core, fuel rods are arranged in coolant tubes to define annular ; spaces for the coolant flow, and the coolant is fed to the spaces at such a ; pressure

H. R. C

1962-01-01

117

NUCLEAR REACTOR  

DOEpatents

A nuclear reactor is described that includes spaced vertical fuel elements centrally disposed in a pressure vessel, a mass of graphite particles in the pressure vessel, means for fluidizing the graphite particles, and coolant tubes in the pressure vessel laterally spaced from the fuel elements. (AEC)

Post, R.G.

1963-05-01

118

NEUTRONIC REACTORS  

DOEpatents

The design of control rods for nuclear reactors are described. In this design the control rod consists essentially of an elongated member constructed in part of a neutron absorbing material and having tube means extending therethrough for conducting a liquid to cool the rod when in use.

Anderson, H.L.

1958-10-01

119

NEUTRONIC REACTOR  

DOEpatents

A reactor is described comprising a plurality of horizontal trays containing a solution of a fissionable material, the trays being sleeved on a vertical tube which contains a vertically-reciprocable control rod, a gas-tight chamber enclosing the trays, and means for conducting vaporized moderator from the chamber and for replacing vaporized moderator in the trays. (AEC)

Wigner, E.P.

1962-12-25

120

REACTOR MONITORING  

DOEpatents

A neutron density inonitoring means for reactors is described. According to this invention a tunnel is provided beneath and spaced from the active portion of the reactor and extends beyond the opposite faces of the activc portion. Neutron beam holes are provided between the active portion and the tunnel and open into the tunnel near the middle thereof. A carriage operates back and forth in the tunnel and is adapted to convey a neutron detector, such as an ion chamber, and position it beneath one of the neutron beam holes. This arrangement affords convenient access of neutron density measuring instruments to a location wherein direct measurement of neutron density within the piles can be made and at the same time affords ample protection to operating personnel.

Bugbee, S.J.; Hanson, V.F.; Babcock, D.F.

1959-02-01

121

NUCLEAR REACTOR  

DOEpatents

A neuclear reactor is described of the heterogeneous type and employing replaceable tubular fuel elements and heavy water as a coolant and moderator. A pluraltty of fuel tubesa having their axes parallel, extend through a tank type pressure vessel which contatns the liquid moderator. The fuel elements are disposed within the fuel tubes in the reaetive portion of the pressure vessel during normal operation and the fuel tubes have removable plug members at each end to permit charging and discharging of the fuel elements. The fuel elements are cylindrical strands of jacketed fissionable material having helical exterior ribs. A bundle of fuel elements are held within each fuel tube with their longitudinal axes parallel, the ribs serving to space them apart along their lengths. Coolant liquid is circulated through the fuel tubes between the spaced fuel elements. Suitable control rod and monitoring means are provided for controlling the reactor.

Treshow, M.

1958-08-19

122

NEUTRONIC REACTOR  

DOEpatents

This patent relates to a reflector means for a neutronic reactor. A reflector comprised of a plurality of vertically movable beryllium control members is provided surrounding the sides of the reactor core. An absorber of fast neutrons comprised of natural uramum surrounds the reflector. An absorber of slow neutrons surrounds the absorber of fast neutrons and is formed of a plurality of beryllium blocks having natural uranium members distributcd therethrough. in addition, a movable body is positioned directly below the core and is comprised of a beryllium reflector and an absorbing member attached to the botiom thereof, the absorbing member containing a substance selected from the goup consisting of natural urantum and Th/sup 232/.

Wade, E.J.

1958-09-16

123

Neutronic reactor  

DOEpatents

A graphite-moderated, water-cooled nuclear reactor including a plurality of rectangular graphite blocks stacked in abutting relationship in layers, alternate layers having axes which are normal to one another, alternate rows of blocks in alternate layers being provided with a channel extending through the blocks, said channeled blocks being provided with concave sides and having smaller vertical dimensions than adjacent blocks in the same layer, there being nuclear fuel in the channels.

Lewis, Warren R. (Richland, WA)

1978-05-30

124

NUCLEAR REACTORS  

DOEpatents

ABS>A graphite moderator structure is presented for a nuclear reactor compriscd of an assembly of similarly orientated prismatic graphite blocks arranged on spaced longitudinal axes lying in common planes wherein the planes of the walls of the blocks are positioned so as to be twisted reintive to the planes of said axes so thatthe unlmpeded dtrect paths in direction wholly across the walls of the blocks are limited to the width of the blocks plus spacing between the blocks.

Long, E.; Ashby, J.W.

1958-09-16

125

NUCLEAR REACTORS  

DOEpatents

An active portion assembly for a fast neutron reactor is described wherein physical distortions resulting in adverse changes in the volume-to-mass ratio are minimized. A radially expandable locking device is disposed within a cylindrical tube within each fuel subassembly within the active portion assembly, and clamping devices expandable toward the center of the active portion assembly are disposed around the periphery thereof. (AEC)

Koch, L.J.; Rice, R.E. Jr.; Denst, A.A.; Rogers, A.J.; Novick, M.

1961-12-01

126

REACTOR CONTROL  

DOEpatents

This patent relates to nuclear reactors of the type which utilize elongited rod type fuel elements immersed in a liquid moderator and shows a design whereby control of the chain reaction is obtained by varying the amount of moderator or reflector material. A central tank for containing liquid moderator and fuel elements immersed therein is disposed within a surrounding outer tank providing an annular space between the two tanks. This annular space is filled with liquid moderator which functions as a reflector to reflect neutrons back into the central reactor tank to increase the reproduction ratio. Means are provided for circulating and cooling the moderator material in both tanks and additional means are provided for controlling separately the volume of moderator in each tank, which latter means may be operated automatically by a neutron density monitoring device. The patent also shows an arrangement for controlling the chain reaction by injecting and varying an amount of poisoning material in the moderator used in the reflector portion of the reactor.

Ruano, W.J.

1957-12-10

127

Nuclear Reactors. Revised.  

ERIC Educational Resources Information Center

|This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: How Reactors Work; Reactor Design; Research, Teaching, and Materials Testing; Reactors (Research, Teaching and Materials); Production Reactors; Reactors for Electric Power…

Hogerton, John F.

128

Fast reactor programme  

Microsoft Academic Search

India's fast reactor programme is described in detail. A 15 MW(e) Fast ; Breeder Test Reactor (FBTR) under construction in the Reactor Research Centre at ; Kalpakkam, will provide experience in construction and operation of a sodium ; cooled fast reactor. Fuel and material testing is an essential aspect of fast ; reactor development. For this purpose, FBTR will serve

Srinivasan

1973-01-01

129

Nuclear Reactors. Revised.  

ERIC Educational Resources Information Center

This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: How Reactors Work; Reactor Design; Research, Teaching, and Materials Testing; Reactors (Research, Teaching and Materials); Production Reactors; Reactors for Electric Power…

Hogerton, John F.

130

POWER PLANT REACTORS  

Microsoft Academic Search

From the point of view of nuclear reaction a picture is drawn of the ; common problems of power plant reactors and their development. After a listing ; of the criteria for classifying reactors, there is a discussion of the basic ; physical, technological, and economic problems involved in twelve different ; reactor types: pressurized water reactor, boiling water reactor,

Kohlmayr

1959-01-01

131

The Solar Collector on Clementine Street.  

ERIC Educational Resources Information Center

Listed are 12 energy activities, experiments, and projects which some eighth-grade students performed in their classroom and local community before they helped install a solar heating system on the roof of an old house during school time and on Saturdays. The building conversion project is described. (KC)

Stranix, Edward; Fleishman, Michael

1980-01-01

132

The Clementine mission: Past, present, and future  

Microsoft Academic Search

During the past decade the Department of Defense, and the Ballistic Missile Defense Organization, BMDO (formally the Strategic Defense Initiative Organization, SDIO) of the US Department of Defense (DoD) have invested heavily in space technology, focused on the development of lighter more cost effective components and systems. With the end of the Cold War many of these technologies can be

Stewart Nozette

1995-01-01

133

Secure reactors  

SciTech Connect

The principle of Process Inherent Ultimate Safety (PIUS) is a new approach to Light Water Reactor (LWR) safety that could represent a solution to the present problems of public distrust, regulatory maze and plant design complexity plaguing the nuclear industry in many countries. A unique thermohydraulic design of the primary system ensures core integrity, and thereby guarantees freedom from significant releases of radioactive matter, in all credible emergencies. This is accomplished entirely without reliance on potentially failure prone engineered safety systems and with immunity to operator mistakes. The potential for human fallibility to cause accidents is thereby drastically reduced in an easily understood way. Plant design can be greatly simplified because redundant, diverse safety systems are no longer needed. The paper briefly describes the PIUS design principle and the two SECURE reactor designs based on it, i.e. SECURE-H for district heating and process steam and SECURE-P (usually known simply as PIUS) for electric power generation. Demonstration of simulated system over-all thermohydraulic function and transient response in a large electrically heated test loop is described and results from some component development work is given.

Hanners, K.

1988-01-01

134

NEUTRONIC REACTOR  

DOEpatents

A power plant is described comprising a turbine and employing round cylindrical fuel rods formed of BeO and UO/sub 2/ and stacks of hexagonal moderator blocks of BeO provided with passages that loosely receive the fuel rods so that coolant may flow through the passages over the fuels to remove heat. The coolant may be helium or steam and fiows through at least one more heat exchanger for producing vapor from a body of fluid separate from the coolant, which fluid is to drive the turbine for generating electricity. By this arrangement the turbine and directly associated parts are free of particles and radiations emanating from the reactor. (AEC)

Daniels, F.

1962-12-18

135

Reactor safety method  

DOEpatents

This invention relates to safety means for preventing a gas cooled nuclear reactor from attaining criticality prior to start up in the event the reactor core is immersed in hydrogenous liquid. This is accomplished by coating the inside surface of the reactor coolant channels with a neutral absorbing material that will vaporize at the reactor's operating temperature.

Vachon, Lawrence J. (Clairton, PA)

1980-03-11

136

REACTOR LABORATORY EXPERIMENTS  

Microsoft Academic Search

An exposition is presented comprising a basic set of experiments in ; reactor physics, engineering, and technology developed by the International ; Institute of Nuclear Science and Engineering. Twenty-two experiments are ; included in a program which may be divided into groups associated with the ; Argonaut Reactor, the AGN-201 Reactor, and with other reactors or auxiliary ; equipment. (J.R.D.);

Sturm; W. J. ed

1961-01-01

137

Heat dissipating nuclear reactor  

Microsoft Academic Search

This patent describes a nuclear reactor containment comprising: reactor vessel disposed in a metal cavity located partially or completely below the surface of the earth in a cavity, a guard vessel, the reactor vessel being positioned within the guard vessel, a thick metal basemat beneath the reactor vessel and guard vessel and at the bottom of the cavity, means located

A. Hunsbedt; J. D. Lazarus

1987-01-01

138

NEUTRONIC REACTOR MANIPULATING DEVICE  

DOEpatents

A cable connecting a control rod in a reactor with a motor outside the reactor for moving the rod, and a helical conduit in the reactor wall, through which the cable passes are described. The helical shape of the conduit prevents the escape of certain harmful radiations from the reactor. (AEC)

Ohlinger, L.A.

1962-08-01

139

Nuclear reactor  

SciTech Connect

A nuclear reactor is described including a vessel, a nuclear core within the vessel and control-rod assemblies within the vessel. The control-rod assemblies include vertical control-rod guide means in a plenum vertically above the core. The control-rod assemblies also include control-rod clusters. Each cluster includes control rods suspended from a spider. The cluster is movable to move its control rods between the guide means and the core, and a drive rod connected to each cluster for so moving each cluster. The vessel has at least an inlet nozzle for supplying a coolant through the core, the inflowing coolant after passing through the core flowing predominantly through the guide means generally vertically, a calandria in the path of the outflowing coolant, from the guide means. The calandria includes hollow members, an upper support for the members perforate to the opening within the members and a lower support. The calandria is mounted with its lower support above and on the guide means and with the drive rods only and not the control rods passing through the hollow members. The lower support is perforate to the coolant flowing out of the guide means. The vessel has at least an outlet nozzle with a generally horizontal coolant outflow channel. The outflow channel is substantially at the level of the calandria so that the coolant flowing into the calandria flows generally transversely over the outer surfaces of the hollow members and out through the outflow channel.

Veronesi, L.; Garner, D.C.

1987-12-29

140

Integration of the Ultraviolet-Visible Spectral Clementine Data and the Gamma-Ray Lunar Prospector Data: Preliminary Results Concerning FeO, TiO2, and Th Abundances of the Lunar Surface at Global Scale  

NASA Astrophysics Data System (ADS)

The Clementine mission (CLM) produced global multispectral data that resulted in a map of FeO and Ti02 concentrations of the lunar surface. The recent Lunar Prospector (LP) mission returned the first global data for the distribution of surface abundances of key elements in lunar rocks, using a gamma-ray spectrometer (GRS) and neutron spectrometer(NS). Integrating CLM mineralogical spectral reflectance and LP chemical data is important to enhance our view of lunar crust origin and evolution, lunar volcanism, and surface processes. Iron, Ti, and Th having relatively large compositional variation over the lunar surface, as well as strong isolated peaks in the GRS spectra, information concerning the distribution and concentration of these elements has been derived from maps of corrected (cosmic ray, nonsymmetric response of the instrument) counting rates only, without converting them into absolute abundances. Maps produced contain count rates in equal-area projection averaged into 5 x 5 degrees latitude/longitude bins, from -90 to +90 degrees latitude and -180 to +180 degrees longitude. In this work, we have used the CLM global FeO and Ti02 abundances (wt%) maps converted at the LP spatial resolution (about 150 km/pixel) to produce FeO and TiO2 GRS abundance maps, through a linear regression based on the analysis of the scatter distribution of both datasets. The regression coefficients have been determined from the data taken between -60 and +60 degrees latitude to avoid uncertainties in the CLM spectral data due to nonnominal conditions of observation at high latitudes. After a critical assessment of the validity of these coefficients for every class of absolute abundance, the LP data have been transformed into absolute abundances for the whole Moon. The Th LP data have been converted into abundances (ppm) using Th concentrations in average soils from the Apollo and Luna sites given. Values of Th abundances for these samples range between 0.5 and 13 ppm. A nonlinear regression has been applied to the LP data, except for low count rate values (corresponding to Th abundances below 1.27 ppm) for which a first-order linear regression has been applied. Statistical tests demonstrate that the Lunar Prospector FeO, TiO2, and Th abundances estimates we have produced through the regressions are reliable. For the LP maps, the uncertainty of absolute FeO and Ti02 estimates is on the same order as that for CLM, i.e., 2 and 1.5 wt% respectively. For the Th, abundance estimates, the uncertainty is about 1-2 ppm. At first order, our global FeO and Ti02 abundances maps from LP are in very good agreement with those obtained from CLM. The Th abundance map is also in good agreement with a recent global Th abundance map, although concentrations have a higher range (0-20 ppm) in our case, and may be slightly overestimated. However, a more detailed comparison between CLM and LP abundance maps of FeO and Ti02 reveals regional differences. Differences between the two datasets are expected because of instrumental and observational causes (spatial resolution, depth of observation), but also because they are sensitive to different types of information (mineralogy vs. chemistry). Maps of differences in abundances between LP and CLM data have been produced for both FeO and Ti02. In relation to the precision of the LP and CLM data, we consider that differences between the two datasets exceeding 2 wt% are significant. Concerning FeO contents, differences up to 4-5 wt% are observed in the South Pole Aitken Basin, and generally at high latitude (up to 70 degrees) in the southern hemisphere, as well as in the northern border (Iridum-Gruithuisen domes region) and the southern border (Sinus Aestum) of the Imbrium Basin. Most important differences, up to 6-7 wt%, are found in Mare Serenitatis, Crisium, and Fecunditatis. Concerning Ti02, most important differences (4-5 wt%) between LP and CLM abundances are located within Mare Tranquillitatis. Differences (about 2-3 wt%) also occur in the northern border of the Imbrium Basin (Ir-Gruithuisen domes region) and in

Chevrel, S. D.; Pinet, P. C.; Barreau, G.; Daydou, Y.; Richard, G.; Maurice, S.; Feldman, W. C.

1999-01-01

141

Ultimate Safe (US) Reactor  

SciTech Connect

The Ultimate Safe (US) Reactor is a reactor that eliminates the traditional safety concerns of nuclear fission reactors. The US reactor has an insignificant source term and no reasonable criticality accident. Furthermore, the negligible residual after-heat in the reactor renders its shutdown capability comparable or superior to conventional power sources. Fission products are continuously removed at the rate they are produced. The reactor is operated with no excess criticality, hence no criticality accident is reasonably possible. The reactor is controlled safely by its negative temperature coeffiient. The reactor maintains criticality by an internal breeding ratio that is trimmed to be exactly one. The US reactor requires a fluid fuel and on-line, continuous fuel processing. Molten salt fuel was selected for its low vapor pressure at high temperature; adequate solubility of uranium and thorium as fluorides; good compatibility with structural materials; absence of irradiation damage; high negative temperature coefficient and amply developed technology and experience.

Gat, U.; Daugherty, S.R.

1985-01-01

142

Tokamak reactor studies  

SciTech Connect

This paper presents an overview of tokamak reactor studies with particular attention to commercial reactor concepts developed within the last three years. Emphasis is placed on DT fueled reactors for electricity production. A brief history of tokamak reactor studies is presented. The STARFIRE, NUWMAK, and HFCTR studies are highlighted. Recent developments that have increased the commercial attractiveness of tokamak reactor designs are discussed. These developments include smaller plant sizes, higher first wall loadings, improved maintenance concepts, steady-state operation, non-divertor particle control, and improved reactor safety features.

Baker, C.C.

1981-01-01

143

Fuel of nuclear reactors.  

National Technical Information Service (NTIS)

This booklet is a presentation of the different steps of the preparation of nuclear fuels performed by Cogema. The documents starts with a presentation of the different French reactor types: graphite moderated reactors, PWRs using MOX fuel, fast breeder r...

1995-01-01

144

Attrition reactor system  

DOEpatents

A reactor vessel for reacting a solid particulate with a liquid reactant has a centrifugal pump in circulatory flow communication with the reactor vessel for providing particulate attrition, resulting in additional fresh surface where the reaction can occur. 2 figures.

Scott, C.D.; Davison, B.H.

1993-09-28

145

The reactor noise threshold  

Microsoft Academic Search

Time-domain noise analysis techniques such as the Rossi-[alpha], the variance-to-mean, and the interval-distribution methods can be used to measure fundamental reactor parameters in a wise variety of reactor systems, provided the power level of the system is not too high. Simple expressions have been derived that define the maximum power level (i.e., the reactor noise threshold) above which time-domain reactor

Spriggs

1994-01-01

146

NEUTRONIC REACTOR POWER PLANT  

DOEpatents

This patent relates to a nuclear reactor power plant incorporating an air-cooled, beryllium oxide-moderated, pebble bed reactor. According to the invention means are provided for circulating a flow of air through tubes in the reactor to a turbine and for directing a sidestream of the circu1ating air through the pebble bed to remove fission products therefrom as well as assist in cooling the reactor. (AEC)

Metcalf, H.E.

1962-12-25

147

Period meter for reactors  

DOEpatents

An improved log N amplifier type nuclear reactor period meter with reduced probability for noise-induced scrams is provided. With the reactor at low power levels a sampling circuit is provided to determine the reactor period by measuring the finite change in the amplitude of the log N amplifier output signal for a predetermined time period, while at high power levels, differentiation of the log N amplifier output signal provides an additional measure of the reactor period.

Rusch, Gordon K. (Downers Grove, IL)

1976-01-06

148

NUCLEAR REACTOR CONTROL SYSTEM  

DOEpatents

A control system is described for a nuclear reactor using enriched uranium fuel of the type of the swimming pool and other heterogeneous nuclear reactors. Circuits are included for automatically removing and inserting the control rods during the course of normal operation. Appropriate safety circuits close down the nuclear reactor in the event of emergency.

Epler, E.P.; Hanauer, S.H.; Oakes, L.C.

1959-11-01

149

Retrofit Russian research reactors  

Microsoft Academic Search

A likely source for enriched uranium for production of a gun-type bomb might be a research reactor. A state or terrorist organization would find the technical process for separating uranium from the reactor fuel plates is simple and well-published. An unguarded research reactor could be found in the former Soviet Union. Russia and the former republics have seen an increasing

Mabe

1993-01-01

150

Improved vortex reactor system  

DOEpatents

An improved vortex reactor system for affecting fast pyrolysis of biomass and Refuse Derived Fuel (RDF) feed materials comprising: a vortex reactor having its axis vertically disposed in relation to a jet of a horizontally disposed steam ejector that impels feed materials from a feeder and solids from a recycle loop along with a motive gas into a top part of said reactor.

Diebold, James P. (Lakewood, CO); Scahill, John W. (Evergreen, CO)

1995-01-01

151

NEUTRONIC REACTOR SHIELDING  

DOEpatents

A special hydrogenous concrete shielding for reactors is described. In addition to Portland cement and water, the concrete essentially comprises 30 to 60% by weight barytes aggregate for enhanced attenuation of fast neutrons. The biological shields of AEC's Oak Ridge Graphite Reactor and Materials Testing Reactor are particular embodiments.

Borst, L.B.

1961-07-11

152

SPECTRAL SHIFT CONTROL REACTOR  

Microsoft Academic Search

The Spectral Shift Control Reactor is a variation of the pressurized-; water reactor. Reactivity control is accomplished by varying the concentration ; of a heavy water-water mixture in the primary loop of the reactor. The addition ; of heavy water changes the relative number of neutrons at any particular energy ; (that is, shifts the neutron spectrum), resulting in more

R. W. Deuster; Z. Levine

1961-01-01

153

High solids fermentation reactor  

DOEpatents

A fermentation reactor and method for fermentation of materials having greater than about 10% solids. The reactor includes a rotatable shaft along the central axis, the shaft including rods extending outwardly to mix the materials. The reactor and method are useful for anaerobic digestion of municipal solid wastes to produce methane, for production of commodity chemicals from organic materials, and for microbial fermentation processes.

Wyman, Charles E. (Lakewood, CO); Grohmann, Karel (Littleton, CO); Himmel, Michael E. (Littleton, CO); Richard, Christopher J. (Lakewood, CO)

1993-01-01

154

Reactor vessel support system  

DOEpatents

A reactor vessel support system includes a support ring at the reactor top supported through a box ring on a ledge of the reactor containment. The box ring includes an annular space in the center of its cross-section to reduce heat flow and is keyed to the support ledge to transmit seismic forces from the reactor vessel to the containment structure. A coolant channel is provided at the outside circumference of the support ring to supply coolant gas through the keyways to channels between the reactor vessel and support ledge into the containment space.

Golden, Martin P. (Trafford, PA); Holley, John C. (McKeesport, PA)

1982-01-01

155

Nuclear reactor overflow line  

DOEpatents

The overflow line for the reactor vessel of a liquid-metal-cooled nuclear reactor includes means for establishing and maintaining a continuous bleed flow of coolant amounting to 5 to 10% of the total coolant flow through the overflow line to prevent thermal shock to the overflow line when the reactor is restarted following a trip. Preferably a tube is disposed concentrically just inside the overflow line extending from a point just inside the reactor vessel to an overflow tank and a suction line is provided opening into the body of liquid metal in the reactor vessel and into the annulus between the overflow line and the inner tube.

Severson, Wayne J. (Pittsburgh, PA)

1976-01-01

156

Fission reactors and materials  

SciTech Connect

The American-designed boiling water reactor and pressurized water reactor dominate the designs currently in use and under construction worldwide. As in all energy systems, materials problems have appeared during service; these include stress-corrosion of stainless steel pipes and heat exchangers and questions regarding crack behavior in pressure vessels. To obtain the maximum potential energy from our limited uranium supplies is is essential to develop the fast breeder reactor. The materials in these reactors are subjected to higher temperatures and neutron fluxes but lower pressures than in the water reactors. The performance required of the fuel elements is more arduous in the breeder than in water reactors. Extensive materials programs are in progress in test reactors and in large test rigs to ensure that materials will be available to meet these conditions.

Frost, B.R.T.

1981-12-01

157

Nuclear reactor construction with bottom supported reactor vessel  

Microsoft Academic Search

This patent describes an improved liquid metal nuclear reactor construction comprising: (a) a nuclear reactor core having a bottom platform support structure; (b) a reactor vessel for holding a large pool of low pressure liquid metal coolant and housing the core; (c) a containment structure surrounding the reactor vessel and having a sidewall spaced outwardly from the reactor vessel side

Sharbaugh

1987-01-01

158

SNTP program reactor design  

NASA Astrophysics Data System (ADS)

The Space Nuclear Thermal Propulsion (SNTP) program is evaluating the feasibility of a particle bed reactor for a high-performance nuclear thermal rocket engine. Reactors operating between 500 MW and 2,000 MW will produce engine thrusts ranging from 20,000 pounds to 80,000 pounds. The optimum reactor arrangement depends on the power level desired and the intended application. The key components of the reactor have been developed and are being tested. Flow-to-power matching considerations dominate the thermal-hydraulic design of the reactor. Optimal propellant management during decay heat cooling requires a three-pronged approach. Adequate computational methods exist to perform the neutronics analysis of the reactor core. These methods have been benchmarked to critical experiment data.

Walton, Lewis A.; Sapyta, Joseph J.

1993-06-01

159

SNAP reactor reentry characteristics  

NASA Astrophysics Data System (ADS)

A comprehensive aerospace nuclear safety program was conducted as part of the SNAP 10A flight test program. Considerable effort was expended to characterize the response of the reactor to reentry conditions. The objective of the reentry studies was to demonstrate the breakup of the reactor and the dispersal of the fuel in the upper atmosphere. The program included analyses and tests of reactor disintegration. Hypersonic and arc jet wind tunnel tests were performed. Additionally, a full-size, nonradioactive model of the SNAP 10A reactor was flight tested. Subsequent analyses of the test results indicated that the reactor could not be broken up during reentry. The results of the SNAP 8 tests were used to validate a thermal computer model for analysis of the reentry behavior of an SP-100 type reactor. The results of the SNAP and SP-100 studies support the current SP-100 position to design for intact reentry for safety purposes.

Smith, Thomas W.; Dix, Terry E.; Mills, Joseph C.

160

THERMAL NEUTRONIC REACTOR  

DOEpatents

A novel thermal reactor was designed in which a first reflector formed from a high atomic weight, nonmoderating material is disposed immediately adjacent to the reactor core. A second reflector composed of a moderating material is disposed outwardly of the first reflector. The advantage of this novel reflector arrangement is that the first reflector provides a high slow neutron flux in the second reflector, where irradiation experiments may be conducted with a small effect on reactor reactivity.

Spinrad, B.I.

1960-01-12

161

Improved vortex reactor system  

DOEpatents

An improved vortex reactor system is described for affecting fast pyrolysis of biomass and Refuse Derived Fuel (RDF) feed materials comprising: a vortex reactor having its axis vertically disposed in relation to a jet of a horizontally disposed steam ejector that impels feed materials from a feeder and solids from a recycle loop along with a motive gas into a top part of said reactor. 12 figs.

Diebold, J.P.; Scahill, J.W.

1995-05-09

162

NEUTRONIC REACTOR SYSTEM  

DOEpatents

A system is described which includes a neutronic reactor containing a dispersion of fissionable material in a liquid moderator as fuel and a conveyor to which a portion of the dispersion may be passed and wherein the self heat of the slurry evaporates the moderator. Means are provided for condensing the liquid moderator and returning it to the reactor and for conveying the dried fissionable material away from the reactor.

Goett, J.J.

1961-01-24

163

FLOW SYSTEM FOR REACTOR  

DOEpatents

A reactor is designed with means for terminating the reaction when returning coolant is below a predetermined temperature. Coolant flowing from the reactor passes through a heat exchanger to a lower reservoir, and then circulates between the lower reservoir and an upper reservoir before being returned to the reactor. Means responsive to the temperature of the coolant in the return conduit terminate the chain reaction when the temperature reaches a predetermined minimum value. (AEC)

Zinn, W.H.

1963-06-11

164

The Oklo Fossil Fission Reactors  

NSDL National Science Digital Library

This web page gives an overview of the Oklo Fossil Fission Reactors, including the history of the area where the reactor is located, the science behind the nuclear reactions, and reasons for studying this nuclear reactor. This page also includes graphics describing the Physics behind the reactors, maps, and pictures of the reactor.

Loss, Robert

2012-06-15

165

The reactor noise threshold  

SciTech Connect

Time-domain noise analysis techniques such as the Rossi-[alpha], the variance-to-mean, and the interval-distribution methods can be used to measure fundamental reactor parameters in a wise variety of reactor systems, provided the power level of the system is not too high. Simple expressions have been derived that define the maximum power level (i.e., the reactor noise threshold) above which time-domain reactor noise techniques are likely to fail in subcritical, critical, and supercritical systems.

Spriggs, G.D. (Los Alamos National Lab., NM (United States))

1994-01-01

166

Pressurized fluidized bed reactor  

DOEpatents

A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine. 1 fig.

Isaksson, J.

1996-03-19

167

HOMOGENEOUS NUCLEAR POWER REACTOR  

DOEpatents

A homogeneous nuclear power reactor utilizing forced circulation of the liquid fuel is described. The reactor does not require fuel handling outside of the reactor vessel during any normal operation including complete shutdown to room temperature, the reactor being selfregulating under extreme operating conditions and controlled by the thermal expansion of the liquid fuel. The liquid fuel utilized is a uranium, phosphoric acid, and water solution which requires no gus exhaust system or independent gas recombining system, thereby eliminating the handling of radioiytic gas.

King, L.D.P.

1959-09-01

168

APDA REACTOR COMPONENTS TEST  

Microsoft Academic Search

A comprehensive description of the test operation and nonnuclear ; performance of the APDA Reactor Components Test is given. These activities were ; carried out in a facility consisting of the reactor, associated fuel handling ; mechanisms, and one primary sodium loop with pump and heat exchanger. A detailed ; description is included of the systems and components of the

R. H. Costello; M. M. Fiedler; J. J. Flis; R. H. Jones; T. E. Lempges; J. Matte; G. Vanmassenhove

1962-01-01

169

NEUTRONIC REACTOR SYSTEM  

DOEpatents

A reactor system incorporating a reactor of the heterogeneous boiling water type is described. The reactor is comprised essentially of a core submerged adwater in the lower half of a pressure vessel and two distribution rings connected to a source of water are disposed within the pressure vessel above the reactor core, the lower distribution ring being submerged adjacent to the uppcr end of the reactor core and the other distribution ring being located adjacent to the top of the pressure vessel. A feed-water control valve, responsive to the steam demand of the load, is provided in the feedwater line to the distribution rings and regulates the amount of feed water flowing to each distribution ring, the proportion of water flowing to the submerged distribution ring being proportional to the steam demand of the load. This invention provides an automatic means exterior to the reactor to control the reactivity of the reactor over relatively long periods of time without relying upon movement of control rods or of other moving parts within the reactor structure.

Treshow, M.

1959-02-10

170

Nuclear reactor architecture  

Microsoft Academic Search

Architecture is presented for nuclear reactors. A special feature is ; that the prestressed concrete vessel presents a shouldering for the support of ; the weight bearing structures. This shouldering is positioned between the inner ; face and the floor of the reactor intended to contain the core. This shouldering ; can be formed by reducing the diameter of the

Tilliette

1971-01-01

171

Nuclear Reactor Overflow Line.  

National Technical Information Service (NTIS)

The overflow line for the reactor vessel of a liquid-metal-cooled nuclear reactor includes means for establishing and maintaining a continuous bleed flow of coolant amounting to 5 to 10 percent of the total coolant flow through the overflow line to preven...

W. J. Severson

1976-01-01

172

THERMAL NUCLEAR REACTOR  

Microsoft Academic Search

Nuclear reactors of the graphite moderated air cooled type in which ; canned slugs or rods of fissile material are employed are discussed. Such a ; reactor may be provided with a means for detecting dust particles in the ; exhausted air. The means employed are lengths of dust absorbent cord suspended ; in vertical holes in the shielding structure

F. W. Fenning; R. F. Jackson

1957-01-01

173

SNAP reactor reentry characteristics  

Microsoft Academic Search

A comprehensive aerospace nuclear safety program was conducted as part of the SNAP 10A flight test program. Considerable effort was expended to characterize the response of the reactor to reentry conditions. The objective of the reentry studies was to demonstrate the breakup of the reactor and the dispersal of the fuel in the upper atmosphere. The program included analyses and

Thomas W. Smith; Terry E. Dix; Joseph C. Mills

1992-01-01

174

POLAND'S FIRST NUCLEAR REACTOR  

Microsoft Academic Search

The first nuclear reactor in Poland which is under construction near the ; Nuclear Research Center in Swierk, near Warsaw, is designed for experimental work ; with high-intensity neutron sources and for production of radioisotopes for ; research in industry and medicine. The reactor uses enriched uranium (10% U\\/sup ; 235\\/) and has a maximum capacity of 2 Mw and

J. Aleksandrowicz; P. Szulc

1958-01-01

175

The secure heating reactor  

SciTech Connect

The SECURE heating reactor was designed by ASEA-ATOM as a realistic alternative for district heating in urban areas and for supplying heat to process industries. SECURE has unique safety characteristics, that are based on fundamental laws of physics. The safety does not depend on active components or operator intervention for shutdown and cooling of the reactor. The inherent safety characteristics of the plant cannot be affected by operator errors. Due to its very low environment impact, it can be sited close to heat consumers. The SECURE heating reactor has been shown to be competitive in comparison with other alternatives for heating Helsinki and Seoul. The SECURE heating reactor forms a basis for the power-producing SECURE-P reactor known as PIUS (Process Inherent Ultimate Safety), which is based on the same inherent safety principles. The thermohydraulic function and transient response have been demonstrated in a large electrically heated loop at the ASEA-ATOM laboratories.

Pind, C.

1987-11-01

176

REACTOR FUEL SCAVENGING MEANS  

DOEpatents

A process for removing fission products from reactor liquid fuel without interfering with the reactor's normal operation or causing a significant change in its fuel composition is described. The process consists of mixing a liquid scavenger alloy composed of about 44 at.% plutoniunm, 33 at.% lanthanum, and 23 at.% nickel or cobalt with a plutonium alloy reactor fuel containing about 3 at.% lanthanum; removing a portion of the fuel and scavenger alloy from the reactor core and replacing it with an equal amount of the fresh scavenger alloy; transferring the portion to a quiescent zone where the scavenger and the plutonium fuel form two distinct liquid layers with the fission products being dissolved in the lanthanum-rich scavenger layer; and the clean plutonium-rich fuel layer being returned to the reactor core. (AEC)

Coffinberry, A.S.

1962-04-10

177

Reactor operations Brookhaven medical research reactor, Brookhaven high flux beam reactor informal monthly report.  

National Technical Information Service (NTIS)

This document is the April 1995 summary report on reactor operations at the Brookhaven Medical Research Reactor and the Brookhaven High Flux Beam Reactor. Ongoing experiments/irradiations in each are listed, and other significant operations functions are ...

H. M. Hauptman J. N. Petro O. Jacobi

1995-01-01

178

Nuclear reactor control column  

DOEpatents

The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest cross-sectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor.

Bachovchin, Dennis M. (Plum Borough, PA)

1982-01-01

179

Reactor Safety Research Programs  

SciTech Connect

This document summarizes the work performed by Pacific Northwest Laboratory (PNL) from January 1 through March 31, 1981, for the Division of Reactor Safety Research within the U.S. Nuclear Regulatory Commission (NRC). Evaluations of nondestructive examination (NDE) techniques and instrumentation are reported; areas of investigation include demonstrating the feasibility of determining the strength of structural graphite, evaluating the feasibility of detecting and analyzing flaw growth in reactor pressure boundary systems, examining NDE reliability and probabilistic fracture mechanics, and assessing the integrity of pressurized water reactor (PWR) steam generator tubes where service-induced degradation has been indicated. Experimental data and analytical models are being provided to aid in decision-making regarding pipeto- pipe impacts following postulated breaks in high-energy fluid system piping. Core thermal models are being developed to provide better digital codes to compute the behavior of full-scale reactor systems under postulated accident conditions. Fuel assemblies and analytical support are being provided for experimental programs at other facilities. These programs include loss-ofcoolant accident (LOCA) simulation tests at the NRU reactor, Chalk River, Canada; fuel rod deformation, severe fuel damage, and postaccident coolability tests for the ESSOR reactor Super Sara Test Program, Ispra, Italy; the instrumented fuel assembly irradiation program at Halden, Norway; and experimental programs at the Power Burst Facility, Idaho National Engineering Laboratory (INEL). These programs will provide data for computer modeling of reactor system and fuel performance during various abnormal operating conditions.

Edler, S. K.

1981-07-01

180

Slurry reactor design studies  

SciTech Connect

The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. (Bechtel Group, Inc., San Francisco, CA (USA)); Akgerman, A. (Texas A and M Univ., College Station, TX (USA)); Smith, J.M. (California Univ., Davis, CA (USA))

1990-06-01

181

REACTOR BASE, SOUTHEAST CORNER. INTERIOR WILL CONTAIN REACTOR TANK, COOLING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REACTOR BASE, SOUTHEAST CORNER. INTERIOR WILL CONTAIN REACTOR TANK, COOLING WATER PIPES, COOLING AIR DUCTS, AND SHIELDING. INL NEGATIVE NO. 776. Unknown Photographer, 10/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

182

Nuclear reactor construction with bottom supported reactor vessel  

Microsoft Academic Search

An improved liquid metal nuclear reactor construction has a reactor core and a generally cylindrical reactor vessel for holding a large pool of low pressure liquid metal coolant and housing the core within the pool. The reactor vessel has an open top end, a closed flat bottom end wall and a continuous cylindrical closed side wall interconnecting the top end

Sharbaugh; John E

1987-01-01

183

Microfluidic electrochemical reactors  

SciTech Connect

A microfluidic electrochemical reactor includes an electrode and one or more microfluidic channels on the electrode, where the microfluidic channels are covered with a membrane containing a gas permeable polymer. The distance between the electrode and the membrane is less than 500 micrometers. The microfluidic electrochemical reactor can provide for increased reaction rates in electrochemical reactions using a gaseous reactant, as compared to conventional electrochemical cells. Microfluidic electrochemical reactors can be incorporated into devices for applications such as fuel cells, electrochemical analysis, microfluidic actuation, pH gradient formation.

Nuzzo, Ralph G. (Champaign, IL); Mitrovski, Svetlana M. (Urbana, IL)

2011-03-22

184

Retrofit Russian research reactors  

SciTech Connect

A likely source for enriched uranium for production of a gun-type bomb might be a research reactor. A state or terrorist organization would find the technical process for separating uranium from the reactor fuel plates is simple and well-published. An unguarded research reactor could be found in the former Soviet Union. Russia and the former republics have seen an increasing number of terrorist incidents, including hijackings and bombings. Recognizing the danger, Russia and the U.S. have explored means of safeguarding former Soviet weapons materials. This article describes some of the plans to reduce the risk of nuclear materials being obtained for illicit weapons production.

Mabe, W.

1993-04-01

185

NEUTRONIC REACTOR CONTROL  

DOEpatents

Methods of controlling reactors are presented. Specifically, a plurality of neutron absorber members are adjustably disposed in the reactor core at different distances from the center thereof. The absorber members extend into the core from opposite faces thereof and are operated by motive means coupled in a manner to simultaneously withdraw at least one of the absorber members while inserting one of the other absorber members. This feature effects fine control of the neutron reproduction ratio by varying the total volume of the reactor effective in developing the neutronic reaction.

Metcalf, H.E.

1958-10-14

186

COOLED NEUTRONIC REACTOR  

DOEpatents

This patent relates to a design for a reactor of the type in which a fluid coolant is flowed through the active portion of the reactor. This design provides for the cooling of the shielding material as well as the reactor core by the same fluid coolant. The core structure is a solid moderator having coolant channels in which are disposed the fuel elements in rod or slug form. The coolant fluid enters the chamber in the shield, in which the core is located, passes over the inner surface of said chamber, enters the core structure at the center, passes through the coolant channels over the fuel elements and out through exhaust ducts.

Binner, C.R.; Wilkie, C.B.

1958-03-18

187

Moving-Medium Biofilm Reactors  

Microsoft Academic Search

Four moving-medium biofilm reactors treating wastewater were reviewed in this paper: the rotating biological contactor (RBC), the moving bed biofilm reactor (MBBR), the vertically moving biofilm reactor (VMBR) and the fluidized-bed reactor (FBR). The RBC process has been applied widely. MBBR is a good process for upgrading current wastewater treatment systems. VMBR is suitable for treating small wastewater flows. FBR

M. Rodgers; X.-M. Zhan

2003-01-01

188

THE SAFETY OF RESEARCH REACTORS  

Microsoft Academic Search

The safety problems of research reactors are discussed. Safety of these ; reactors depends principally from the rahin them, and the penetrating radiations ; emitted. The safety requirements for reactivity containments, control ; instruments and mechanisms, guaranteed supplies, and operations of the research ; reactors are described. The safety problems of high-flux reactors (10 to 20 Mwt) ; are discussed

1961-01-01

189

Fusion reactor radioactive waste management  

Microsoft Academic Search

Quantities and compositions of non-tritium radioactive waste are estimated for some current conceptual fusion reactor designs, and disposal of large amounts of radioactive waste appears necessary. Although the initial radioactivity of fusion reactor and fission reactor wastes are comparable, the radionuclides in fusion reactor wastes are less hazardous and have shorter half-lives. Areas requiring further research are discussed.

J. D. Kaser; A. K. Postma; D. J. Bradley

1976-01-01

190

Method of operating nuclear reactors  

Microsoft Academic Search

A method of operating a nuclear reactor wherein the reactor is operated for more than 50% of its operating period with the control rod patterns in which, in the central region of the reactor core accounting for at least 50% thereof, the control rods inserted from the bottom of the reactor core are at the depths of between 16\\/24 and

M. Izumi; H. Maruyama; R. Takeda; S. Uchikawa

1981-01-01

191

Indian fusion test reactor  

NASA Astrophysics Data System (ADS)

The fusion reactor as a volumetric neutron source can serve many applications needed for realizing fusion power reactor. For the Indian energy scenario, such a device can also produce fissile fuel for accelerating the nuclear power production. The Indian Fusion Test Reactor (FTR) is a low fusion gain (Q = 3-5) device to be used as component test facility for qualifying future reactor materials as well as for demonstrating the production of fissile fuel. FTR will be a medium sized tokamak device with a neutron wall load of 0.2 MW/m2. The presently available structural materials can be used for this device and such a device can be realized in ten years time from now. This device should produce about 25-50 kg of fissile fuel in one full-power-year and also produce the tritium needed for its operation. This device will greatly help the nuclear fission power program by producing fissile fuel.

Srinivasan, R.; FTR Team

2012-06-01

192

Research Reactor Benchmarks  

SciTech Connect

A criticality benchmark experiment performed at the Jozef Stefan Institute TRIGA Mark II research reactor is described. This experiment and its evaluation are given as examples of benchmark experiments at research reactors. For this reason the differences and possible problems compared to other benchmark experiments are particularly emphasized. General guidelines for performing criticality benchmarks in research reactors are given. The criticality benchmark experiment was performed in a normal operating reactor core using commercially available fresh 20% enriched fuel elements containing 12 wt% uranium in uranium-zirconium hydride fuel material. Experimental conditions to minimize experimental errors and to enhance computer modeling accuracy are described. Uncertainties in multiplication factor due to fuel composition and geometry data are analyzed by sensitivity analysis. The simplifications in the benchmark model compared to the actual geometry are evaluated. Sample benchmark calculations with the MCNP and KENO Monte Carlo codes are given.

Ravnik, Matjaz; Jeraj, Robert [J. Stefan Institute (Slovenia)

2003-09-15

193

NEUTRONIC REACTOR STRUCTURE  

DOEpatents

A reactor core, comprised of vertical stacks of hexagonal blocks of beryllium oxide having axial cylindrical apertures extending therethrough and cylindrical rods of a sintered mixture of uranium dioxide and beryllium oxide, is described. (AEC)

Daniels, F.

1961-10-24

194

Advanced spheromak fusion reactor  

SciTech Connect

The spheromak has no toroidal magnetic field coils or other structure along its geometric axis, and is thus more attractive than the leading magnetic fusion reactor concept, the tokamak. As a consequence of this and other attributes, the spheromak reactor may be compact and produce a power density sufficiently high to warrant consideration of a liquid `blanket` that breeds tritium, converts neutron kinetic energy to heat, and protects the reactor vessel from severe neutron damage. However, the physics is more complex, so that considerable research is required to learn how to achieve the reactor potential. Critical physics problems and possible ways of solving them are described. The opportunities and issues associated with a possible liquid wall are considered to direct future research.

Fowler, T.K. [California Univ., Berkeley, CA (United States). Dept. of Nuclear Engineering; Hooper, E.B. [Lawrence Livermore National Lab., CA (United States)

1996-06-19

195

Reactor vessel sectioning demonstration  

Microsoft Academic Search

A technical demonstration was successfully completed of simulated reactor vessel sectioning using the combined techniques of air arc gouging and flame cutting. A 4-ft x 3-ft x 9-in. thick sample was fabricated of A36 carbon steel to simulate a reactor vessel wall. A 1\\/4-in. layer of stainless steel (SS) was tungsten inert gas (TIG)-welded to the carbon steel. Several techniques

Lundgren

1981-01-01

196

(Fusion reactor materials)  

Microsoft Academic Search

The purpose of this trip is to participate and present a paper in the Fourth International Conference on Fusion Reactor Materials (ICFRM-4) at Kyoto, Japan, December 4--8, 1989; and to participate in two workshops at the University of Tokyo: (1) Fusion Reactor Fuel-Materials Interactions, December 11--12, 1989, and (2) P-149, United States-Japan Workshop on Evaluation of Radiation Damage in Ceramics

1990-01-01

197

K-Reactor readiness  

SciTech Connect

This document describes some of the more significant accomplishments in the reactor restart program and details the magnitude and extent of the work completed to bring K-Reactor to a state of restart readiness. The discussion of restart achievements is organized into the three major categories of personnel, programs, and plant. Also presented is information on the scope and extent of internal and external oversight of the efforts, as well as some details on the startup plan.

Rice, P.D.

1991-12-04

198

Compact power reactor  

DOEpatents

There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector.

Wetch, Joseph R. (Woodland Hills, CA); Dieckamp, Herman M. (Canoga Park, CA); Wilson, Lewis A. (Canoga Park, CA)

1978-01-01

199

Alkylation reactor quality control  

SciTech Connect

This patent describes an apparatus comprising: an alkylation reactor; a fractional distillation column means; means for withdrawing a mixture containing unreacted isoparaffin as a reactor effluent stream from the alkylation reactor, and for providing the reactor effluent stream as a feed to the fractional distillation column means wherein at least a portion of the unreacted isoparaffin is separated to form a predominantly isoparaffin containing recycle stream; means for combining an isoparaffin-containing fluid stream with an olefin-containing fluid stream to form a combined isoparaffin and olefin stream; means for combining the recycle stream and the combined paraffin and olefin stream to form a combined feed stream and for providing the combined feed stream to the alkylation reactor; means for establishing a first signal representative of the desired isoparaffin-to-olefin ratio in the combined feed stream; means for establishing a second signal representative of the flow rate of the combined feed stream; means for establishing a third signal representative of the flow rate of the isoparaffin-containing fluid stream; means for establishing a fourth signal representative of the flow rate of the reactor effluent stream; analyzer means for detecting the concentration of olefin supplied through the combined feed stream; and for detecting the concentration of isoparaffin supplied through the combined feed stream, and for detecting the molecular weight of the combined feed stream; computer means responsive to the analyzer means and to the first, second, third and fourth signals; means for manipulating the flow rate of the isoparaffin containing fluid stream in response to the first control signal, means for manipulating the flow rate of the reactor effluent stream in response to the second control signal, to thereby maintain the liquid level in the alkylation reactor essentially constant.

Funk, G.L.; Bard, W.B.

1987-12-15

200

Reactor Safety Research Programs  

SciTech Connect

This document summarizes the work performed by Pacific Northwest laboratory from October 1 through December 31, 1979, for the Division of Reactor Safety Research within the Nuclear Regulatory Commission. Evaluation of nondestructive examination (NDE) techniques and instrumentation are reported; areas of investigation include demonstrating the feasibilty of determining structural graphite strength, evaluating the feasibilty of detecting and analyzing flaw growth in reactor pressure boundary systems, examining NDE reliability and probabilistic fracture mechanics, and assessing the remaining integrity of pressurized water reactor steam generator tubes where service-induced degradation has been indicated. Test assemblies and analytical support are being provided for experimental programs at other facilities. These programs include the loss-of-coolant accident simulation tests at the NRU reactor, Chalk River, Canada; the fuel rod deformation and post-accident coolability tests for the ESSOR Test Reactor Program, lspra, Italy; the blowdown and reflood tests in the test facility at Cadarache, France; the instrumented fuel assembly irradiation program at Halden, Norway; and the experimental programs at the Power Burst Facility, Idaho National Engineering Laboratory. These programs will provide data for computer modeling of reactor system and fuel performance during various abnormal operating conditions.

Dotson, CW

1980-08-01

201

NEUTRONIC REACTOR CONSTRUCTION AND OPERATION  

DOEpatents

A method is given for operating a nuclear reactor having a negative coefficient of reactivity to compensate for the change in reactor reactivity due to the burn-up of the xenon peak following start-up of the reactor. When it is desired to start up the reactor within less than 72 hours after shutdown, the temperature of the reactor is lowered prior to start-up, and then gradually raised after start-up.

West, J.M.; Weills, J.T.

1960-03-15

202

REACTOR GROUT THERMAL PROPERTIES  

SciTech Connect

Savannah River Site has five dormant nuclear production reactors. Long term disposition will require filling some reactor buildings with grout up to ground level. Portland cement based grout will be used to fill the buildings with the exception of some reactor tanks. Some reactor tanks contain significant quantities of aluminum which could react with Portland cement based grout to form hydrogen. Hydrogen production is a safety concern and gas generation could also compromise the structural integrity of the grout pour. Therefore, it was necessary to develop a non-Portland cement grout to fill reactors that contain significant quantities of aluminum. Grouts generate heat when they set, so the potential exists for large temperature increases in a large pour, which could compromise the integrity of the pour. The primary purpose of the testing reported here was to measure heat of hydration, specific heat, thermal conductivity and density of various reactor grouts under consideration so that these properties could be used to model transient heat transfer for different pouring strategies. A secondary purpose was to make qualitative judgments of grout pourability and hardened strength. Some reactor grout formulations were unacceptable because they generated too much heat, or started setting too fast, or required too long to harden or were too weak. The formulation called 102H had the best combination of characteristics. It is a Calcium Alumino-Sulfate grout that contains Ciment Fondu (calcium aluminate cement), Plaster of Paris (calcium sulfate hemihydrate), sand, Class F fly ash, boric acid and small quantities of additives. This composition afforded about ten hours of working time. Heat release began at 12 hours and was complete by 24 hours. The adiabatic temperature rise was 54 C which was within specification. The final product was hard and displayed no visible segregation. The density and maximum particle size were within specification.

Steimke, J.; Qureshi, Z.; Restivo, M.; Guerrero, H.

2011-01-28

203

REACTOR AND NOVEL METHOD  

DOEpatents

A nuclear reactor of the type which uses a liquid fuel and a method of controlling such a reactor are described. The reactor is comprised essentially of a tank for containing the liquid fuel such as a slurry of discrete particles of fissionnble material suspended in a heavy water moderator, and a control means in the form of a disc of neutron absorbirg material disposed below the top surface of the slurry and parallel thereto. The diameter of the disc is slightly smaller than the diameter of the tank and the disc is perforated to permit a flow of the slurry therethrough. The function of the disc is to divide the body of slurry into two separate portions, the lower portion being of a critical size to sustain a nuclear chain reaction and the upper portion between the top surface of the slurry and the top surface of the disc being of a non-critical size. The method of operation is to raise the disc in the reactor until the lower portion of the slurry has reached a critical size when it is desired to initiate the reaction, and to lower the disc in the reactor to reduce the size of the lower active portion the slurry to below criticality when it is desired to stop the reaction.

Young, G.J.; Ohlinger, L.A.

1958-06-24

204

Reactor antineutrino anomaly  

SciTech Connect

Recently, new reactor antineutrino spectra have been provided for {sup 235}U, {sup 239}Pu, {sup 241}Pu, and {sup 238}U, increasing the mean flux by about 3%. To a good approximation, this reevaluation applies to all reactor neutrino experiments. The synthesis of published experiments at reactor-detector distances <100 m leads to a ratio of observed event rate to predicted rate of 0.976{+-}0.024. With our new flux evaluation, this ratio shifts to 0.943{+-}0.023, leading to a deviation from unity at 98.6% C.L. which we call the reactor antineutrino anomaly. The compatibility of our results with the existence of a fourth nonstandard neutrino state driving neutrino oscillations at short distances is discussed. The combined analysis of reactor data, gallium solar neutrino calibration experiments, and MiniBooNE-{nu} data disfavors the no-oscillation hypothesis at 99.8% C.L. The oscillation parameters are such that |{Delta}m{sub new}{sup 2}|>1.5 eV{sup 2} (95%) and sin{sup 2}(2{theta}{sub new})=0.14{+-}0.08 (95%). Constraints on the {theta}{sub 13} neutrino mixing angle are revised.

Mention, G.; Fechner, M. [CEA, Irfu, SPP, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Lasserre, Th.; Cribier, M. [CEA, Irfu, SPP, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Astroparticule et Cosmologie APC, 10 rue Alice Domon et Leonie Duquet, 75205 Paris cedex 13 (France); Mueller, Th. A.; Lhuillier, D.; Letourneau, A. [CEA, Irfu, SPhN, Centre de Saclay, F-91191 Gif-sur-Yvette (France)

2011-04-01

205

Mimic of OSU research reactor  

SciTech Connect

The Ohio State University research reactor (OSURR) is undergoing improvements in its research and educational capabilities. A computer-based digital data acquisition system, including a reactor system mimic, will be installed as part of these improvements. The system will monitor the reactor system parameters available to the reactor operator either in digital parameters available to the reactor operator either in digital or analog form. The system includes two computers. All the signals are sent to computer 1, which processes the data and sends the data through a serial port to computer 2 with a video graphics array VGA monitor, which is utilized to display the mimic system of the reactor.

Lu, Hong; Miller, D.W. (Ohio State Univ., Columbus (United States))

1991-11-01

206

Looking Southwest at Reactor Box Furnaces With Reactor Boxes and ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Looking Southwest at Reactor Box Furnaces With Reactor Boxes and Repossessed Uranium in Recycle Recovery Building - Hematite Fuel Fabrication Facility, Recycle Recovery Building, 3300 State Road P, Festus, Jefferson County, MO

207

Heat dissipating nuclear reactor  

DOEpatents

Disclosed is a nuclear reactor containment adapted to retain and cool core debris in the unlikely event of a core meltdown and subsequent breach in the reactor vessel. The reactor vessel is seated in a cavity which has a thick metal sidewall that is integral with a thick metal basemat at the bottom of the cavity. The basemat extends beyond the perimeter of the cavity sidewall. Underneath the basemat is a porous bed with water pipes and steam pipes running into it. Water is introduced into the bed and converted into steam which is vented to the atmosphere. A plurality of metal pilings in the form of H-beams extends from the metal base plate downwardly and outwardly into the earth.

Hunsbedt, Anstein (Los Gatos, CA); Lazarus, Jonathan D. (Sunnyvale, CA)

1987-01-01

208

A NEUTRONIC REACTOR  

DOEpatents

A nuclear reactor for producing thermoelectric power is described. The reactor core comprises a series of thermoelectric assemblies, each assembly including fissionable fuel as an active element to form a hot junction and a thermocouple. The assemblies are disposed parallel to each other to form spaces and means are included for Introducing an electrically conductive coolant between the assemblies to form cold junctions of the thermocouples. An electromotive force is developed across the entire series of the thermoelectric assemblies due to fission heat generated in the fuel causing a current to flow perpendicular to the flow of coolant and is distributed to a load outside of the reactor by means of bus bars electrically connected to the outermost thermoelectric assembly.

Luebke, E.A.; Vandenberg, L.B.

1959-09-01

209

Heat dissipating nuclear reactor  

DOEpatents

Disclosed is a nuclear reactor containment adapted to retain and cool core debris in the unlikely event of a core meltdown and subsequent breach in the reactor vessel. The reactor vessel is seated in a cavity which has a thick metal sidewall that is integral with a thick metal basemat at the bottom of the cavity. The basemat extends beyond the perimeter of the cavity sidewall. Underneath the basemat is a porous bed with water pipes and steam pipes running into it. Water is introduced into the bed and converted into steam which is vented to the atmosphere. A plurality of metal pilings in the form of H-beams extend from the metal base plate downwardly and outwardly into the earth.

Hunsbedt, A.; Lazarus, J.D.

1985-11-21

210

Reactor for exothermic reactions  

DOEpatents

A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

1993-03-02

211

Reactor for exothermic reactions  

DOEpatents

A liquid phase process for oligomerization of C.sub.4 and C.sub.5 isoolefins or the etherification thereof with C.sub.1 to C.sub.6 alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120.degree. to 300.degree. F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

Smith, Jr., Lawrence A. (Bellaire, TX); Hearn, Dennis (Houston, TX); Jones, Jr., Edward M. (Friendswood, TX)

1993-01-01

212

MERCHANT MARINE SHIP REACTOR  

DOEpatents

A nuclear reactor is described for use in a merchant marine ship. The reactor is of pressurized light water cooled and moderated design in which three passes of the water through the core in successive regions of low, intermediate, and high heat generation and downflow in a fuel region are made. The foregoing design makes a compact reactor construction with extended core life. The core has an egg-crate lattice containing the fuel elements confined between a lower flow baffle and upper grid plate, with the latter serving also as part of a turn- around manifold from which the entire coolant is distributed into the outer fuel elements for the second pass through the core. The inner fuel elements are cooled in the third pass.

Mumm, J.F.; North, D.C. Jr.; Rock, H.R.; Geston, D.K.

1961-05-01

213

MERCHANT MARINE SHIP REACTOR  

DOEpatents

A nuclear reactor for use in a merchant marine ship is described. The reactor is of pressurized, light water cooled and moderated design in which three passes of the water through the core in successive regions of low, intermediate, and high heat generation and downflow in a fuel region are made. The design makes a compact reactor construction with extended core life. The core has an egg-crate lattice containing the fuel elements that are confined between a lower flow baffle and upper grid plate, with the latter serving also as part of a turn- around manifold from which the entire coolant is distributed into the outer fuel elements for the second pass through the core. The inner fuel elements are cooled in the third pass. (AEC)

Sankovich, M.F.; Mumm, J.F.; North, D.C. Jr.; Rock, H.R.; Gestson, D.K.

1961-05-01

214

Thermionic Reactor Design Studies  

SciTech Connect

Paper presented at the 29th IECEC in Monterey, CA in August 1994. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their (thermionic reactor) performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling.

Schock, Alfred

1994-08-01

215

Fusion Reactor Control  

NASA Astrophysics Data System (ADS)

The plasma kinetic temperature and density changes, each per an injected fuel density rate increment, control the energy supplied by a thermonuclear fusion reactor in a power production cycle. This could include simultaneously coupled control objectives for plasma current, horizontal and vertical position, shape and burn control. The minimum number of measurements required, use of indirect (not plasma parameters) system measurements, and distributed control procedures for burn control are to be verifiable in a time dependent systems code. The International Thermonuclear Experimental Reactor (ITER) has the need to feedback control both the fusion output power and the driven plasma current, while avoiding damage to diverter plates. The system engineering of fusion reactors must be performed to assure their development expeditiously and effectively by considering reliability, availability, maintainability, environmental impact, health and safety, and cost.

Plummer, Dirk

2003-10-01

216

Diagnostics for hybrid reactors  

SciTech Connect

The Hybrid Reactor(HR) can be considered an attractive actinide-burner or a fusion assisted transmutation for destruction of transuranic(TRU) nuclear waste. The hybrid reactor has two important subsystems: the tokamak neutron source and the blanket which includes a fuel zone where the TRU are placed and a tritium breeding zone. The diagnostic system for a HR must be as simple and robust as possible to monitor and control the plasma scenario, guarantee the protection of the machine and monitor the transmutation.

Orsitto, Francesco Paolo [ENEA Unita' Tecnica Fusione , Associazione ENEA-EURATOM sulla Fusione C R Frascati v E Fermi 45 00044 Frascati (Italy)

2012-06-19

217

Nuclear reactor apparatus  

DOEpatents

A lifting, rotating and sealing apparatus for nuclear reactors utilizing rotating plugs above the nuclear reactor core. This apparatus permits rotation of the plugs to provide under the plug refueling of a nuclear core. It also provides a means by which positive top core holddown can be utilized. Both of these operations are accomplished by means of the apparatus lifting the top core holddown structure off the nuclear core while stationary, and maintaining this structure in its elevated position during plug rotation. During both of these operations, the interface between the rotating member and its supporting member is sealingly maintained.

Wade, Elman E. (Ruffs Dale, PA)

1978-01-01

218

MEANS FOR SHIELDING REACTORS  

DOEpatents

A reactor of the heterageneous, heavy water moderated type is described. The reactor is comprised of a plurality of vertically disposed fuel element tubes extending through a tank of heavy water moderator and adapted to accommodate a flow of coolant water in contact with the fuel elements. A tank containing outgoing coolant water is disposed above the core to function is a radiation shield. Unsaturated liquid hydrocarbon is floated on top of the water in the shield tank to reduce to a minimum the possibility of the occurrence of explosive gaseous mixtures resulting from the neutron bombardment of the water in the shield tank.

Garrison, W.M.; McClinton, L.T.; Burton, M.

1959-03-10

219

NEUTRONIC REACTOR SYSTEM  

DOEpatents

Gas-cooled solid-moderator type reactors wherein the fissionable fuel and moderator materials are each in the form of solid pebbles, or discrete particles, and are substantially homogeneously mixed in the proper proportion and placed within the core of the reactor are described. The shape of these discrete particles must be such that voids are present between them when mixed together. Helium enters the bottom of the core and passes through the voids between the fuel and moderator particles to absorb the heat generated by the chain reaction. The hot helium gas is drawn off the top of the core and may be passed through a heat exchanger to produce steam.

Daniels, F.

1957-10-15

220

United States Domestic Research Reactor Infrastrucutre TRIGA Reactor Fuel Support  

Microsoft Academic Search

The United State Domestic Research Reactor Infrastructure Program at the Idaho National Laboratory manages and provides project management, technical, quality engineering, quality inspection and nuclear material support for the United States Department of Energy sponsored University Reactor Fuels Program. This program provides fresh, unirradiated nuclear fuel to Domestic University Research Reactor Facilities and is responsible for the return of the

Douglas Morrell

2011-01-01

221

Evaluation of Torsatrons as reactors.  

National Technical Information Service (NTIS)

Stellarators have significant operational advantages over tokamaks as ignited steady-state reactors. This scoping study, which uses an integrated cost-minimization code that incorporates costing and reactor component models self-consistently with a 1-D en...

J. F. Lyon K. Gulec R. L. Miller L. El-Guebaly

1994-01-01

222

Reactor operation environmental information document  

SciTech Connect

The Savannah River Site (SRS) produces nuclear materials, primarily plutonium and tritium, to meet the requirements of the Department of Defense. These products have been formed in nuclear reactors that were built during 1950--1955 at the SRS. K, L, and P reactors are three of five reactors that have been used in the past to produce the nuclear materials. All three of these reactors discontinued operation in 1988. Currently, intense efforts are being extended to prepare these three reactors for restart in a manner that protects human health and the environment. To document that restarting the reactors will have minimal impacts to human health and the environment, a three-volume Reactor Operations Environmental Impact Document has been prepared. The document focuses on the impacts of restarting the K, L, and P reactors on both the SRS and surrounding areas. This volume discusses the geology, seismology, and subsurface hydrology. 195 refs., 101 figs., 16 tabs.

Haselow, J.S.; Price, V.; Stephenson, D.E.; Bledsoe, H.W.; Looney, B.B.

1989-12-01

223

SPERT I REACTOR SAFETY STUDIES  

Microsoft Academic Search

The results of experimental studies of reactor kinetic behavior under ; runaway conditions are reported for the unpressurized Spert I reactor. ; Reactivity step transients and ramp transients are considered. Spert I core ; characteristics are given. (W.D.M.);

W. E. Nyer; S. G. Forbes

1958-01-01

224

The First Reactor.  

ERIC Educational Resources Information Center

On December 2, 1942, in a racquet court underneath the West Stands of Stagg Field at the University of Chicago, a team of scientists led by Enrico Fermi created the first controlled, self-sustaining nuclear chain reaction. This updated and revised story of the first reactor (or "pile") is based on postwar interviews (as told to Corbin Allardice…

Department of Energy, Washington, DC.

225

NEUTRONIC REACTOR FUEL ELEMENT  

DOEpatents

A reactor fuel element of the capillary tube type is described. The element consists of a thin walled tube, sealed at both ends, and having an interior coatlng of a fissionable material, such as uranium enriched in U-235. The tube wall is gas tight and is constructed of titanium, zirconium, or molybdenum.

Kesselring, K.A.; Seybolt, A.U.

1958-12-01

226

NUCLEAR REACTOR CONTROL MEANS  

Microsoft Academic Search

A reactor controi rod is patented, which can effect shut down when the ; control-rod channels are distorted by earthquakes or other disturbances. The ; control rod consists of a hollow casing suspended in a vertical channel by a ; cable. The casing is filled with discrete spherical particles of neutron-; absorbing material, such as boron steel. If distortion of

Firth

1963-01-01

227

Shielding for reactors  

Microsoft Academic Search

A brief introductory discussion is given of the design of shielding for nuclear reactors. It includes consideration of design requirements, choice of materials and dimensions, nuclear reactions that affect the penetration, heating of the shielding and production of radioactivity in the coolant. Because the basic data available are insufficient for high accuracy in design calculation, the use of very complex

G C Laurence

1956-01-01

228

Radiation damage in reactors  

Microsoft Academic Search

From topical conference on energy; Chicago, Illinois, USA (4 Feb 1974). ; Fuel, cladding, structural materials, moderators, coolants, pressure vessels, and ; other components of nuclear reactors are bombarded by fast and thermal neutrons ; (with fluxes up to and above 10¹ cm² sec¹) at elevated ; temperatures. Fuel elements are also exposed to fission fragments; all ; components are

Vineyard

1973-01-01

229

Radiation Damage in Reactors  

Microsoft Academic Search

Fuel, cladding, and structural materials, moderators, coolants, pressure vessels, and other components of nuclear reactors are bombarded by fast and thermal neutrons (with fluxes up to and above 1015 cm?2 sec?1) at elevated temperatures. Fuel elements are also exposed to fission fragments; all components are exposed to high fluxes of gamma rays. As a result the physical properties of materials

G. H. Vineyard

1974-01-01

230

Radiation Damage in Reactors  

Microsoft Academic Search

Fuel, cladding, and structural materials, moderators, coolants, pressure vessels, and other components of nuclear reactors are bombarded by fast and thermal neutrons (with fluxes up to and above 1015 cm-2 sec-1) at elevated temperatures. Fuel elements are also exposed to fission fragments; all components are exposed to high fluxes of gamma rays. As a result the physical properties of materials

G. H. Vineyard

1974-01-01

231

Fast Reactor Technology Preservation  

Microsoft Academic Search

There is renewed worldwide interest in developing and implementing a new generation of advanced fast reactors. International cooperative efforts are underway such as the Global Nuclear Energy Partnership (GNEP). Advanced computer modeling and simulation efforts are a key part of these programs. A recognized and validated set of Benchmark Cases are an essential component of such modeling efforts. Testing documentation

David W. Wootan; Ronald P. Omberg

2008-01-01

232

DRAGON reactor operating experience  

Microsoft Academic Search

BS>From international nuclear industries fair; Basel, Switzerland (16 ; Oct 1972). Although the primary purpose of the Dragon Reactor is to irradiate ; experimental HTR fuels, these activities generate a great deal of useful ; experience in operational areas such as helium utilization, the design and ; maintenance of helium components and circuits, and the behavior of radioactive ; species.

1972-01-01

233

NEUTRONIC REACTOR STRUCTURE  

DOEpatents

A neutronic reactor is described. It has a core consisting of natural uranium and heavy water and having a K-factor greater than unity which is surrounded by a reflector consisting of natural uranium and ordinary water having a Kfactor less than unity.

Weinberg, A.M.; Vernon, H.C.

1961-05-30

234

NEUTRONIC REACTOR STRUCTURE  

DOEpatents

The neutronic reactor is comprised of a core consisting of natural uranium and heavy water with a K-factor greater than unity. The core is surrounded by a reflector consisting of natural uranium and ordinary water with a Kfactor less than unity. (AEC)

Vernon, H.C.; Weinberg, A.M.

1961-05-30

235

Fluidized catalytic cracking reactor  

SciTech Connect

A fluidized catalytic cracking unit wherein cyclone diplegs extend from the reactor vessel into the stripping vessel, for reducing the overall height of the unit. Valve means are provided at the lower end of the diplegs to prevent blow by of gas through the diplegs. The diplegs pass through the vent lines.

Brown, J.D.; Jahnke, F.C.; Maclean, J.P.; Williams, D.

1980-09-02

236

Control of nuclear reactors  

SciTech Connect

In a coupling system for a nuclear reactor control rod and control rod drive, said coupling system being selectively uncouplable by an uncoupling rod, a system of passages for exercising a countervailing force on the uncoupling rod to prevent inadvertent uncoupling during scram.

Fischer, L. E.; Bean, J. E.

1985-06-04

237

Antimatter reactor dynamics  

Microsoft Academic Search

In this report the power production characteristics of a matter-antimatter reactor are described in a general way. These calculations are almost independent of the details of the particular antimatter confinement scheme used. With only minor modifications they apply equally as well to any of the currently envisioned confinement and reaction schemes.

R. R. Zito

1986-01-01

238

Fusion reactor materials  

NASA Astrophysics Data System (ADS)

This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics.

239

NEUTRONIC REACTOR FUEL ELEMENT  

DOEpatents

A fuel slug for a reactor which acts as a safety device is described. The fuel slug is an aluminum tube with a foil lining the inside surface of the tube, the foil being fabricated of uranium in a lead matrix.

Horning, W.A.; Lanning, D.D.; Donahue, D.J.

1959-10-01

240

Kazakhstan Reactor Becomes Operational.  

National Technical Information Service (NTIS)

The reactor is a powerful source of neutron and gamma-radiation and is designed for a wide range of scientific research experiments. Water is used both as the moderator and the reflector as well as for the coolant. It is fueled with enriched uranium, and ...

1968-01-01

241

Catalytic reactor design  

SciTech Connect

Most major processes in the chemical process industries are built around heterogeneous chemical reactions. A solid catalyst is an integral part of almost all these operations. In new-construction or retrofit projects for such plants, process engineers must design and specify not only the reactors but also the catalysts. Independent design of the two, without concern for how they will mesh, can mean a more costly design, a low production rate and more-frequent shutdowns. It may even cause the catalyst to fail. Consider, for instance, this debacle at a methanol plant. A carbon-steel pipe had been installed at the entrance to the methanol reactor. High-pressure carbon monoxide in the feed stream reacted with the steel to produce iron carbonyls, which poisoned the catalyst. Remedying the situation cost several million dollars. With the hope of avoiding such situations, the authors first summarize the principles of catalyst and reactor design, with emphasis on maintaining interdependence between the two activities. Then they apply the principles to industrial reactors. The focus is solely on heterogeneous catalysis, in which the catalyst (virtually always in solid form) is not in the same phase as the process stream. Even with this limitation, the technology is far too detailed for full presentation here. Instead, the aim is to enable readers to keep the big picture in mind whenever getting immersed in the specifies of a project.

Bartholomew, C.H.; Hecker, W.C. (Brigham Young Univ., Provo, UT (United States))

1994-06-01

242

ETF reactor design status  

Microsoft Academic Search

Conceptual design studies of a tokamak Engineering Test Facility (ETF) are being carried out as a joint laboratory-industry effort at the ETF Design Center at Oak Ridge National Laboratory (ORNL). Designs are being developed for two reactors, one with a bundle divertor and one with a poloidal divertor. These machines, which are designed for ignition and a burn time of

Sager

1980-01-01

243

ETF reactor design status  

Microsoft Academic Search

Conceptual design studies of a tokamak Engineering Test Facility (ETF) are being carried out as a joint laboratory--industry effort at the ETF Design Center at Oak Ridge National Laboratory (ORNL). Designs are being developed for two reactors, one with a bundle divertor and one with a poloidal divertor. These machines, which are designed for ignition and a burn time of

P. H. Sager

1981-01-01

244

Nuclear reactor control apparatus  

Microsoft Academic Search

Nuclear reactor core safety rod release apparatus comprises a control rod having a detent notch in the form of an annular peripheral recess at its upper end, a control rod support tube for raising and lowering the control rod under normal conditions, latches pivotally mounted on the control support tube with free ends thereof normally disposed in the recess in

Sridhar

1983-01-01

245

Nuclear reactor control apparatus  

Microsoft Academic Search

Nuclear reactor core safety rod release apparatus comprises a control rod having a detent notch in the form of an annular peripheral recess at its upper end, a control rod support tube for raising and lowering the control rod under normal conditions, latches pivotally mounted on the control support tube with free ends thereof normally disposed in the recess in

Sridhar

1981-01-01

246

Nuclear Reactors and Technology  

SciTech Connect

This publication Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency`s Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on the Energy Science and Technology Database and Nuclear Science Abstracts (NSA) database. Current information, added daily to the Energy Science and Technology Database, is available to DOE and its contractors through the DOE Integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user`s needs.

Cason, D.L.; Hicks, S.C. [eds.

1992-01-01

247

Inertial fusion reactors (review)  

Microsoft Academic Search

The current status of the work on engineering problems of inertial fusion is reviewed. The state of laboratory physics research, aspects of driver choice, and pellet designs are discussed. Particular attention is paid to the development of inertial fusion reactors and their energy applications. It is shown that lasers with output energies in the 0.5-5.0 MJ range must be acknowledged

A V Kalinin

1984-01-01

248

Stabilized Spheromak Fusion Reactors  

SciTech Connect

The U.S. fusion energy program is focused on research with the potential for studying plasmas at thermonuclear temperatures, currently epitomized by the tokamak-based International Thermonuclear Experimental Reactor (ITER) but also continuing exploratory work on other plasma confinement concepts. Among the latter is the spheromak pursued on the SSPX facility at LLNL. Experiments in SSPX using electrostatic current drive by coaxial guns have now demonstrated stable spheromaks with good heat confinement, if the plasma is maintained near a Taylor state, but the anticipated high current amplification by gun injection has not yet been achieved. In future experiments and reactors, creating and maintaining a stable spheromak configuration at high magnetic field strength may require auxiliary current drive using neutral beams or RF power. Here we show that neutral beam current drive soon to be explored on SSPX could yield a compact spheromak reactor with current drive efficiency comparable to that of steady state tokamaks. Thus, while more will be learned about electrostatic current drive in coming months, results already achieved in SSPX could point to a productive parallel development path pursuing auxiliary current drive, consistent with plans to install neutral beams on SSPX in the near future. Among possible outcomes, spheromak research could also yield pulsed fusion reactors at lower capital cost than any fusion concept yet proposed.

Fowler, T

2007-04-03

249

REACTOR UNLOADING MEANS  

DOEpatents

A means for remotely unloading irradiated fuel slugs from a neutronic reactor core and conveying them to a remote storage tank is reported. The means shown is specifically adapted for use with a reactor core wherein the fuel slugs are slidably held in end to end abutting relationship in the horizontal coolant flow tubes, the slugs being spaced from tae internal walls of the tubes to permit continuous circulation of coolant water therethrough. A remotely operated plunger at the charging ends of the tubes is used to push the slugs through the tubes and out the discharge ends into a special slug valve which transfers the slug to a conveying tube leading into a storage tank. Water under pressure is forced through the conveying tube to circulate around the slug to cool it and also to force the slug through the conveving tube into the storage tank. The slug valve and conveying tube are shielded to prevent amy harmful effects caused by the radioactive slug in its travel from the reactor to the storage tank. With the disclosed apparatus, all the slugs in the reactor core can be conveyed to the storage tank shortly after shutdown by remotely located operating personnel.

Cooper, C.M.

1957-08-20

250

Reactor component automatic grapple  

DOEpatents

A grapple for handling nuclear reactor components in a medium such as liquid sodium which, upon proper seating and alignment of the grapple with the component as sensed by a mechanical logic integral to the grapple, automatically seizes the component. The mechanical logic system also precludes seizure in the absence of proper seating and alignment.

Greenaway, Paul R. (Bethel Park, PA)

1982-01-01

251

NEUTRONIC REACTOR FUEL ELEMENT  

DOEpatents

A chemically nonreactive fuel composition for incorporation in aluminum- clad, plate type fuel elements for neutronic reactors is described. The composition comprises a mixture of aluminum and uranium carbide particles, the uranium carbide particles containing at least 80 wt.% UC/sub 2/.

Picklesimer, M.L.; Thurber, W.C.

1961-01-01

252

Nuclear reactor building  

DOEpatents

A reactor building for enclosing a nuclear reactor includes a containment vessel having a wetwell disposed therein. The wetwell includes inner and outer walls, a floor, and a roof defining a wetwell pool and a suppression chamber disposed there above. The wetwell and containment vessel define a drywell surrounding the reactor. A plurality of vents are disposed in the wetwell pool in flow communication with the drywell for channeling into the wetwell pool steam released in the drywell from the reactor during a LOCA for example, for condensing the steam. A shell is disposed inside the wetwell and extends into the wetwell pool to define a dry gap devoid of wetwell water and disposed in flow communication with the suppression chamber. In a preferred embodiment, the wetwell roof is in the form of a slab disposed on spaced apart support beams which define there between an auxiliary chamber. The dry gap, and additionally the auxiliary chamber, provide increased volume to the suppression chamber for improving pressure margin. 4 figures.

Gou, P.F.; Townsend, H.E.; Barbanti, G.

1994-04-05

253

NUCLEAR REACTOR COOLANT  

DOEpatents

The formation of new reactor coolants which suppress polymerization resulting from pyrolitic and radiation decomposition is described. The coolants consist of polyphenyls and condensed ring compounds having from two to about four carbon rings and from 0.1 to about 10% of an alkall metal dispersed in the hydrocarbon.

Colichman, E.L.

1959-10-20

254

University Reactor Instrumentation Program  

SciTech Connect

Recognizing that the University Reactor Instrumentation Program was developed in response to widespread needs in the academic community for modernization and improvement of research and training reactors at institutions such as the University of Florida, the items proposed to be supported by this grant over its two year period have been selected as those most likely to reduce foreed outages, to meet regulatory concerns that had been expressed in recent years by Nuclear Regulatory Commission inspectors or to correct other facility problems and limitations. Department of Energy Grant Number DE-FG07-90ER129969 was provided to the University of Florida Training Reactor(UFTR) facility through the US Department of Energy's University Reactor Instrumentation Program. The original proposal submitted in February, 1990 requested support for UFTR facility instrumentation and equipment upgrades for seven items in the amount of $107,530 with $13,800 of this amount to be the subject of cost sharing by the University of Florida and $93,730 requested as support from the Department of Energy. A breakdown of the items requested and total cost for the proposed UFTR facility instrumentation and equipment improvements is presented.

Vernetson, W.G.

1992-11-01

255

In and Out Reactor  

NSDL National Science Digital Library

Students learn about material balances, a fundamental concept of chemical engineering. They use stoichiometry to predict the mass of carbon dioxide that escapes after reacting measured quantities of sodium bicarbonate with dilute acetic acid. Students then react the chemicals in a small reactor made from a plastic water bottle and balloon.

Integrated Teaching and Learning Program, College of Engineering,

256

Catalytic reactor design  

Microsoft Academic Search

Most major processes in the chemical process industries are built around heterogeneous chemical reactions. A solid catalyst is an integral part of almost all these operations. In new-construction or retrofit projects for such plants, process engineers must design and specify not only the reactors but also the catalysts. Independent design of the two, without concern for how they will mesh,

C. H. Bartholomew; W. C. Hecker

1994-01-01

257

Cryostat for Reactor Irradiation  

Microsoft Academic Search

A cryostat for continuously bathing samples in liquid nitrogen or other heat transfer liquids during nuclear reactor irradiation has been constructed and successfully operated. The samples to be irradiated at low temperature are immersed in the heat transfer fluid which is high-purity liquified nitrogen circulating in a closed system at a pressure greater than that of the atmosphere. The liquid

C. C. Sartain; H. P. Yockey

1958-01-01

258

MULTISTAGE FLUIDIZED BED REACTOR  

DOEpatents

A multistage fluidized bed reactor is described in which each of a number of stages is arranged with respect to an associated baffle so that a fluidizing gas flows upward and a granular solid downward through the stages and baffles, whereas the granular solid stopsflowing downward when the flow of fluidizing gas is shut off.

Jonke, A.A.; Graae, J.E.A.; Levitz, N.M.

1959-11-01

259

MOLTEN-SALT BREEDER REACTORS  

Microsoft Academic Search

The problems involved in buildiing a molten-salt thermalbreeder reactor ; are reviewed, and it is concluded that the most feasible construction is an ; externally-cooled reactor with the fuel salt passing through the reactcr core in ; graphite tubes. A reactor with 15% of the core vollume occupied by fuel salt and ; 5% occupied by fertile salt would have

MacPherson

1960-01-01

260

Nuclear Reactor Engineering Analysis Laboratory  

Microsoft Academic Search

The Nuclear Reactor Engineering Analysis Laboratory (NREAL) is a sophisticated computer system with state-of-the-art analytical tools and technology for analysis of light water reactors. Multiple application software tools can be activated to carry out different analyses and studies such as nuclear fuel reload evaluation, safety operation margin measurement, transient and severe accident analysis, nuclear reactor instability, operator training, normal and

Carlos Chavez-Mercado; Jaime B. Morales-Sandoval; Benjamin E. Zayas-Perez

1998-01-01

261

SIMPLIFIED SODIUM GRAPHITE REACTOR SYSTEM  

Microsoft Academic Search

This patent relates to a nuclear power reactor comprising a reactor ; vessel, shielding means positioned at the top of said vessel, means sealing said ; reactor vessel to said shielding means, said vessel containing a quantity of ; sodium, a core tank, unclad graphite moderator disposed in said tank, means ; including a plurality of process tubes traversing said

1963-01-01

262

Lunar Surface Reactor Shielding Study  

Microsoft Academic Search

A nuclear reactor system could provide power to support long term human exploration of the moon. Such a system would require shielding to protect astronauts from its emitted radiations. Shielding studies have been performed for a Gas Cooled Reactor system because it is considered to be the most suitable nuclear reactor system available for lunar exploration, based on its tolerance

Shawn Kang; Ronald Lipinski; William McAlpine

2006-01-01

263

Reactor for hydrogenating coal slurry  

Microsoft Academic Search

A multi-stage reactor for hydrogenating coal slurry in a pressure vessel for pressures of up to 700 bar, preferably of up to 350 bar, with inlets for gas and coal slurry through the reactor bottom, an outlet for sludge, gases and vapors in the reactor top, and dividing trays in the pressure vessel, by means of which trays the individual

R. Schulz; H. Kuerten; H. Puestel; G. Weber

1984-01-01

264

Reactor monitoring using antineutrino detectors  

NASA Astrophysics Data System (ADS)

Nuclear reactors have served as the antineutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Measurements made with antineutrino detectors could therefore offer an alternative means for verifying the power history and fissile inventory of a reactor as part of International Atomic Energy Agency (IAEA) and/or other reactor safeguards regimes. Several efforts to develop this monitoring technique are underway worldwide.

Bowden, N. S.

2011-08-01

265

Reactor physics activities in Japan  

NASA Astrophysics Data System (ADS)

This report reviews the research activity in reactor physics field in Japan during July, 1992 - July, 1993. The review was performed in the following fields: nuclear data evaluation, calculational method development, fast reactor physics, thermal reactor physics, advanced core design, fusion reactor neutronics, nuclear criticality safety, shielding, incineration of radioactive nuclear wastes, noise analysis and control and national programs. The main references were taken from journals and reports published during this period. The research committee of reactor physics is responsible for the review work.

1994-01-01

266

Hybrid space nuclear reactor concept  

NASA Astrophysics Data System (ADS)

A hybrid space nuclear reactor which can provide both electrical power and thermal propulsion has been found to have significant benefits for near term military satellites; it combines the STAR-C thermionic reactor with NERVA rocket propulsion technology. This hybrid reactor would use a W/UO2 cermet core which was developed in the nuclear rocket program of the 1960s. Both the reactor core and the thermionic converters can be tested prior to launch. The design of a 10 kW(e) reactor capable of producing over 1300 N of thrust is described.

Begg, Lester L.; Choong, Phillip T.; Teofilo, Vincent L.; Dunn, Charles; Bhattacharyya, Sam

267

Integrated Microfluidic Reactors  

PubMed Central

Summary Microfluidic reactors exhibit intrinsic advantages of reduced chemical consumption, safety, high surface-area-to-volume ratios, and improved control over mass and heat transfer superior to the macroscopic reaction setting. In contract to a continuous-flow microfluidic system composed of only a microchannel network, an integrated microfluidic system represents a scalable integration of a microchannel network with functional microfluidic modules, thus enabling the execution and automation of complicated chemical reactions in a single device. In this review, we summarize recent progresses on the development of integrated microfluidics-based chemical reactors for (i) parallel screening of in situ click chemistry libraries, (ii) multistep synthesis of radiolabeled imaging probes for positron emission tomography (PET), (iii) sequential preparation of individually addressable conducting polymer nanowire (CPNW), and (iv) solid-phase synthesis of DNA oligonucleotides. These proof-of-principle demonstrations validate the feasibility and set a solid foundation for exploring a broad application of the integrated microfluidic system.

Lin, Wei-Yu; Wang, Yanju; Wang, Shutao; Tseng, Hsian-Rong

2009-01-01

268

Reactor head shielding apparatus  

SciTech Connect

This patent describes a nuclear reactor head shielding apparatus for mounting on spaced reactor head lifting members radially inwardly of the head bolts. It comprises a frame of sections for mounting on the lifting members and extending around the top central area of the head, mounting means for so mounting the frame sections, including downwardly projecting members on the frame sections and complementary upwardly open recessed members for fastening to the lifting members for receiving the downwardly projecting members when the frame sections are lowered thereto with lead shielding supported thereby on means for hanging lead shielding on the frame to minimize radiation exposure or personnel working with the head bolts or in the vicinity thereof.

Schukei, G.E.; Roebelen, G.J.

1992-01-28

269

MEANS FOR COOLING REACTORS  

DOEpatents

A design of a reactor is presented in which the fuel elements may be immersed in a liquid coolant when desired without the necessity of removing them from the reactor structure. The fuel elements, containing the fissionable material are in plate form and are disposed within spaced slots in a moderator material, such as graphite to form the core. Adjacent the core is a tank containing the liquid coolant. The fuel elements are mounted in spaced relationship on a rotatable shaft which is located between the core and the tank so that by rotation of the shaft the fuel elements may be either inserted in the slots in the core to sustain a chain reaction or immersed in the coolant.

Wheeler, J.A.

1957-11-01

270

Neutronic reactor construction  

DOEpatents

1. A neutronic reactor comprising a moderator including horizontal layers formed of horizontal rows of graphite blocks, alternate layers of blocks having the rows extending in one direction, the remaining alternate layers having the rows extending transversely to the said one direction, alternate rows of blocks in one set of alternate layers having longitudinal ducts, the moderator further including slotted graphite tubes positioned in the ducts, the reactor further comprising an aluminum coolant tube positioned within the slotted tube in spaced relation thereto, bodies of thermal-neutron-fissionable material, and jackets enclosing the bodies and being formed of a corrosion-resistant material having a low neutron-capture cross section, the bodies and jackets being positioned within the coolant tube so that the jackets are spaced from the coolant tube.

Huston, Norman E. (Fullerton, CA)

1976-07-06

271

Nuclear reactor safety device  

DOEpatents

A safety device is described for use in a nuclear reactor for axially repositioning a control rod with respect to the reactor core in the event of a thermal excursion. It comprises a laminated strip helically configured to form a tube, said tube being in operative relation to said control rod. The laminated strip is formed of at least two materials having different thermal coefficients of expansion, and is helically configured such that the material forming the outer lamina of the tube has a greater thermal coefficient of expansion than the material forming the inner lamina of said tube. In the event of a thermal excursion the laminated strip will tend to curl inwardly so that said tube will increase in length, whereby as said tube increases in length it exerts a force on said control rod to axially reposition said control rod with respect to said core.

Hutter, E.

1983-08-15

272

NEUTRONIC REACTOR CORE INSTRUMENT  

DOEpatents

A multi-purpose instrument for measuring neutron flux, coolant flow rate, and coolant temperature in a nuclear reactor is described. The device consists essentially of a hollow thimble containing a heat conducting element protruding from the inner wall, the element containing on its innermost end an amount of fissionsble materinl to function as a heat source when subjected to neutron flux irradiation. Thermocouple type temperature sensing means are placed on the heat conducting element adjacent the fissionable material and at a point spaced therefrom, and at a point on the thimble which is in contact with the coolant fluid. The temperature differentials measured between the thermocouples are determinative of the neutron flux, coolant flow, and temperature being measured. The device may be utilized as a probe or may be incorporated in a reactor core. (AE C)

Mims, L.S.

1961-08-22

273

AIR COOLED NEUTRONIC REACTOR  

DOEpatents

A nuclear reactor of the air-cooled, graphite moderated type is described. The active core consists of a cubicle mass of graphite, approximately 25 feet in each dimension, having horizontal channels of square cross section extending between two of the opposite faces, a plurality of cylindrical uranium slugs disposed in end to end abutting relationship within said channels providing a space in the channels through which air may be circulated, and a cadmium control rod extending within a channel provided in the moderator. Suitable shielding is provlded around the core, as are also provided a fuel element loading and discharge means, and a means to circulate air through the coolant channels through the fuel charels to cool the reactor.

Fermi, E.; Szilard, L.

1958-05-27

274

Integrated Microfluidic Reactors.  

PubMed

Microfluidic reactors exhibit intrinsic advantages of reduced chemical consumption, safety, high surface-area-to-volume ratios, and improved control over mass and heat transfer superior to the macroscopic reaction setting. In contract to a continuous-flow microfluidic system composed of only a microchannel network, an integrated microfluidic system represents a scalable integration of a microchannel network with functional microfluidic modules, thus enabling the execution and automation of complicated chemical reactions in a single device. In this review, we summarize recent progresses on the development of integrated microfluidics-based chemical reactors for (i) parallel screening of in situ click chemistry libraries, (ii) multistep synthesis of radiolabeled imaging probes for positron emission tomography (PET), (iii) sequential preparation of individually addressable conducting polymer nanowire (CPNW), and (iv) solid-phase synthesis of DNA oligonucleotides. These proof-of-principle demonstrations validate the feasibility and set a solid foundation for exploring a broad application of the integrated microfluidic system. PMID:20209065

Lin, Wei-Yu; Wang, Yanju; Wang, Shutao; Tseng, Hsian-Rong

2009-12-01

275

ENGINEERING TEST REACTOR  

DOEpatents

Heterogeneous reactors of the type which is both cooled and moderated by the same fluid, preferably water, and employs highly enriched fuel are reported. In this design, an inner pressure vessel is located within a main outer pressure vessel. The reactor core and its surrounding reflector are disposed in the inner pressure vessel which in turn is surrounded by a thermal shield, Coolant fluid enters the main pressure vessel, fiows downward into the inner vessel where it passes through the core containing tbe fissionable fuel assemblies and control rods, through the reflector, thence out through the bottom of the inner vessel and up past the thermal shield to the discharge port in the main vessel. The fuel assemblles are arranged in the core in the form of a cross having an opening extending therethrough to serve as a high fast flux test facility.

De Boisblanc, D.R.; Thomas, M.E.; Jones, R.M.; Hanson, G.H.

1958-10-21

276

Polarized advanced fuel reactors  

SciTech Connect

The d-/sup 3/He reaction has the same spin dependence as the d-t reaction. It produces no neutrons, so that if the d-d reactivity could be reduced, it would lead to a neutron-lean reactor. The current understanding of the possible suppression of the d-d reactivity by spin polarization is discussed. The question as to whether a suppression is possible is still unresolved. Other advanced fuel reactions are briefly discussed. 11 refs.

Kulsrud, R.M.

1987-07-01

277

REACTOR CONTROL DEVICE  

DOEpatents

A shadow control device for controlling a nuclear reactor is described. The device comprises a series of hollow neutron-absorbing elements arranged in groups, each element having a cavity for substantially housing an adjoining element and a longitudinal member for commonly supporting the groups of elements. Longitudinal actuation of the longitudinal member distributes the elements along its entire length in which position maximum worth is achieved.

Kaufman, H.B.; Weiss, A.A.

1959-08-18

278

7 CFR 319.56-34 - Clementines from Spain.  

Code of Federal Regulations, 2010 CFR

...to participate in and follow the Mediterranean fruit fly management program established... (c) Management program for Mediterranean fruit fly; monitoring. The Government of Spain's Mediterranean fruit fly (Ceratitis...

2009-01-01

279

7 CFR 319.56-34 - Clementines from Spain.  

Code of Federal Regulations, 2010 CFR

...to participate in and follow the Mediterranean fruit fly management program established... (c) Management program for Mediterranean fruit fly; monitoring. The Government of Spain's Mediterranean fruit fly (Ceratitis...

2010-01-01

280

Reactor vessel sectioning demonstration  

SciTech Connect

A technical demonstration was successfully completed of simulated reactor vessel sectioning using the combined techniques of air arc gouging and flame cutting. A 4-ft x 3-ft x 9-in. thick sample was fabricated of A36 carbon steel to simulate a reactor vessel wall. A 1/4-in. layer of stainless steel (SS) was tungsten inert gas (TIG)-welded to the carbon steel. Several techniques were considered to section the simulated reactor vessel; air arc gouging was selected to penetrate the stainless steel, and flame cutting was selected to sever the carbon steel. Three sectioning operations were demonstrated. For all three, the operating parameters were the same; but the position of the sample was varied. For the first cut, the sample was placed in a horizontal position, and it was successfully severed from the SS side. For the second cut, the sample was turned over and cut from the carbon steel side. Cutting from the carbon steel side has the advantages of cost reduction

Lundgren, R.A.

1981-09-01

281

Exhaust gas reactor  

SciTech Connect

A reactor for the oxidation of unburned and partially burned components in the exhaust gas from an internal combustion engine comprising a chamber which is substantially circular in cross sections perpendicular to its axis, one or more inlet pipes which pass a mixture of exhaust gas and air substantially tangentially into the chamber near to one end thereof, and an outlet pipe near to the other end of the chamber and which is so arranged that exhaust gas leaves the chamber substantially tangentially. The tangential inlet and tangential outlet of gases minimizes energy losses in the gas passing through the reactor. The ratio of the cross-sectional areas of the inlet pipe(s) to reactor chamber is preferably from 1:9 to 25:36, and similar ranges of crosssectional area ratios are preferred for the outlet pipe and chamber. The ratio of the length of the reaction chamber to diameter is preferably from 1:1 to 4:1. The chamber may be cylindrical or divergent from inlet end to outlet end and may be thermally insulated.

Camarsa, M.; Cocchiara, F.; Garcea, G.P.

1981-11-24

282

Thermionic Reactor Design Studies  

SciTech Connect

During the 1960's and early 70's the author performed extensive design studies, analyses, and tests aimed at thermionic reactor concepts that differed significantly from those pursued by other investigators. Those studies, like most others under Atomic Energy Commission (AEC and DOE) and the National Aeronautics and Space Administration (NASA) sponsorship, were terminated in the early 1970's. Some of this work was previously published, but much of it was never made available in the open literature. U.S. interest in thermionic reactors resumed in the early 80's, and was greatly intensified by reports about Soviet ground and flight tests in the late 80's. This recent interest resulted in renewed U.S. thermionic reactor development programs, primarily under Department of Defense (DOD) and Department of Energy (DOE) sponsorship. Since most current investigators have not had an opportunity to study all of the author's previous work, a review of the highlights of that work may be of value to them. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling. Where the author's concepts differed from the later Topaz-2 design was in the relative location of the emitter and the collector. Placing the fueled emitter on the outside of the cylindrical diodes permits much higher axial conductances to reduce ohmic losses in the electrodes of full-core-height diodes. Moreover, placing the fuel on the outside of the diode makes possible reactors with much higher fuel volume fractions, which enable power-flattened fast reactors scalable to very low power levels without the need for life-limiting hydride moderators or the use of efficiency-limiting driver fuel. In addition, with the fuel on the outside its swelling does not increase the emitter diameter or reduce the interelectrode gap. This should permit long lifetimes even with closer spacings, which can significantly improve the system efficiences. This was confirmed by coupled neutronic, thermal, thermionic, and electrical system analyses - some of which are presented in this paper - and by subsequent experiments. A companion paper presented next describes the fabrication and testing of full-scale converter elements, both fueled and unfueled, and summarizes the test results obtained. There is a duplicate copy in the file.

Schock, Alfred

1994-06-01

283

Reactor Monitoring with Neutrino Detectors  

NASA Astrophysics Data System (ADS)

The study of the use of neutrino detectors to monitor nuclear reactors is currently a very active field of research. While neutrino detectors located close to reactors have been used to provide information about the global performance of the reactors, a general improvement of the technique is needed in order to use it in a practical way to monitor the fissile contents of the fuel of the nuclear reactors or the thermal power delivered. I describe the current status of the Angra Neutrino Project, aimed to building a low-mass neutrino detector to monitor the Angra II reactor of the Brazilian nuclear power plant Almirante Alvaro Ramos in order to explore new approaches to reactor monitoring with neutrino detectors.

Casimiro Linares, Edgar

2011-09-01

284

Designing Reactors to Facilitate Decommissioning  

SciTech Connect

Critics of nuclear power often cite issues with tail-end-of-the-fuel-cycle activities as reasons to oppose the building of new reactors. In fact, waste disposal and the decommissioning of large nuclear reactors have proven more challenging than anticipated. In the early days of the nuclear power industry the design and operation of various reactor systems was given a great deal of attention. Little effort, however, was expended on end-of-the-cycle activities, such as decommissioning and disposal of wastes. As early power and test reactors have been decommissioned difficulties with end-of-the-fuel-cycle activities have become evident. Even the small test reactors common at the INEEL were not designed to facilitate their eventual decontamination, decommissioning, and dismantlement. The results are that decommissioning of these facilities is expensive, time consuming, relatively hazardous, and generates large volumes of waste. This situation clearly supports critics concerns about building a new generation of power reactors.

Richard H. Meservey

2006-06-01

285

Acceptability of reactors in space  

SciTech Connect

Reactors are the key to our future expansion into space. However, there has been some confusion in the public as to whether they are a safe and acceptable technology for use in space. The answer to these questions is explored. The US position is that when reactors are the preferred technical choice, that they can be used safely. In fact, it does not appear that reactors add measurably to the risk associated with the Space Transportation System.

Buden, D.

1981-01-01

286

COMPACT HIGH TEMPERATURE REACTOR (CHTR)  

Microsoft Academic Search

Summary CHTR is a mainly 233U-Thorium fuelled, lead-bismuth cooled and beryllium oxide moderated reactor. This reactor, initially being developed to generate about 100 kWTh power, will have a core life of 15 years and will have several advanced passive safety features to enable its operation as compact power pack in remote areas not connected to the electrical grid. The reactor

I. V. Dulera; A. Basak; P. P. Kelkar; R. K. Sinha

287

When Do Commercial Reactors Permanently Shut Down?  

EIA Publications

For those wishing to obtain current data, the following resources are available: U.S. reactors, go to EIA's nuclear reactor shutdown list. (Note: As of April 30, 2010, the last U.S. reactor to permanently shut down was Big Rock Point in 1997.) Foreign Reactors, go to the Power Reactor Information System (PRIS) on the International Atomic Energy Agency's website.

Information Center

2011-05-10

288

NEUTRONIC REACTOR CHARGING AND DISCHARGING  

DOEpatents

A method and arrangement is presented for removing a fuel element from a neutronic reactor tube through which a liquid coolant is being circulaled. The fuel element is moved into a section of the tube beyond the reactor proper, and then the coolant in the tube between the fuel element and the reactor proper is frozen, so that the fuel element may be removed from the tube without loss of the coolant therein. The method is particularly useful in the case of a liquid metal- cooled reactor.

Zinn, W.H.

1959-07-14

289

FUEL ASSAY REACTOR  

DOEpatents

A reactor having maximum sensitivity to perturbations is described comprising a core consisting of a horizontally disposed, rectangular, annular fuel zone containing enriched uranium dioxide dispersed in graphite, the concentration of uranium dioxide increasing from the outside to the inside of the fuel zone, an internal reflector of graphite containing an axial test opening disposed within the fuel zone, an external graphite reflector, means for changing the neutron spectrum in the test opening, and means for measuring perturbations in the neutron flux caused by the introduction of different fuel elements into the test opening. (AEC)

Spinrad, B.I.; Sandmeier, H.A.; Martens, F.H.

1962-12-25

290

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

Scott, Charles D. (Oak Ridge, TN); Marasco, Joseph A. (Kingston, TN)

1995-01-01

291

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary and tertiary particulate phases, continuously introduced and removed simultaneously in the cocurrent and countercurrent mode, act in a role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Means for introducing and removing the sorbent phases include feed screw mechanisms and multivane slurry valves.

Scott, Charles D. (Oak Ridge, TN); Marasco, Joseph A. (Kingston, TN)

1996-01-01

292

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

Scott, Charles D. (Oak Ridge, TN)

1993-01-01

293

Protecting reactors from terrorists  

SciTech Connect

A review of the available data on changing terrorist trends suggests that the design basis threat assumed by the Nuclear Regulatory Commission (NRC) and the security and safeguards precautions that flow from them are dangerously out of step with reality. Both the number of incidents and the nature of terrorism has changed, and the presumption of any moral or political constraints has vanished. Two major areas of concern are steps to eliminate protection at research and test reactors and the sensitive security information the NRC routinely issues in public documents, including a series of scientific assessments of how to penetrate security barriers. 8 references, 4 figures.

Hirsch, D.; Murphy, S.; Ramberg, B.

1986-03-01

294

POWER BREEDER REACTOR  

DOEpatents

An arrangement is offered for preventing or minimizing the contraction due to temperature rise, of a reactor core comprising vertical fuel rods in sodium. Temperature rise of the fuel rods would normally make them move closer together by inward bowing, with a resultant undesired increase in reactivity. According to the present invention, assemblies of the fuel rods are laterally restrained at the lower ends of their lower blanket sections and just above the middle of the fuel sections proper of the rods, and thus the fuel sections move apart, rather than together, with increase in temperature.

Monson, H.O.

1960-11-22

295

NEUTRONIC REACTOR CONSTRUCTION  

DOEpatents

A cover device is described for the fuel element receiving tube of a neutronic reactor of the heterogeneous, water cooled type wherein said tubes are arranged in a moderator with their longitudinal axes vertical. The cover is provided with means to support a rod-type fuel element from the bottom thereof and means to lock the cover in place, the latter being adapted for remote operation. This cover device is easily removable and seals the opening in the upper end of the fuel tube against leakage of coolant.

Vernon, H.C.; Goett, J.J.

1958-09-01

296

Sequencing Batch Reactors  

Microsoft Academic Search

\\u000a A sequencing batch reactor (SBR) can be either a biological SBR (BIO-SBR) or a physicochemical SBR (PC-SBR). BIO-SBR includes\\u000a traditional sedimentation biological SBR, innovative flotation biological SBR (BIO-DAF-SBR), innovative membrane biological\\u000a SBR (MBR-SBR), aerobic digestion SBR (AD-SBR), etc. All PC-SBR are innovative processes including at least sedimentation PC-SBR\\u000a (PC-SED-SBR), flotation PC-SBR (PC-DAF-SBR), membrane PC-SBR (PC-membrance-SBR), granular activated carbon PC-SBR (PC-GAC-SBR),

Lawrence K. Wang; Yan Li

297

FCC reactor effluent sampling  

SciTech Connect

Optimizing the FCC unit requires fast and accurate measurements of the effects of operating variables on yields. Unfortunately, the FCC unit material balance is often uncertain due to the complexity of product recovery systems and the injection of extraneous streams into the gas plant. Reactor effluent sampling, or Reaction Mix Sampling (RMS) as it is sometimes called, provides a faster, more accurate method of obtaining FCC unit performance data compared to standard test run techniques. This paper describes the RMS procedure and illustrates how it was used at the Ultramar refinery in Wilmington, California, to quantify the effect of two major operating variables.

Campagna, R.J.; Bricklemyer (Refining Process Services, Cheswick, PA (US)); Bodnar, W.M.; Laux, M.A.; Chung, H. (Ultramar Refining, Long Beach, CA (US))

1989-01-01

298

NUCLEAR REACTOR FUEL ELEMENT  

DOEpatents

A plate type fuel element which is particularly useful for organic cooled reactors is described. Generally, the fuel element comprises a plurality of fissionable fuel bearing plates held in spaced relationship by a frame in which the plates are slidably mounted in grooves. Clearance is provided in the grooves to allow the plates to expand laterally. The plates may be rigidly interconnected but are floatingly supported at their ends within the frame to allow for longi-tudinal expansion. Thus, this fuel element is able to withstand large temperature differentials without great structural stresses. (AEC)

Anderson, W.F.; Tellefson, D.R.; Shimazaki, T.T.

1962-04-10

299

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system is described which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary and tertiary particulate phases, continuously introduced and removed simultaneously in the cocurrent and countercurrent mode, act in a role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Means for introducing and removing the sorbent phases include feed screw mechanisms and multivane slurry valves. 3 figs.

Scott, C.D.; Marasco, J.A.

1996-02-27

300

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figs.

Scott, C.D.; Marasco, J.A.

1995-04-25

301

FOOD IRRADIATION REACTOR  

DOEpatents

An irradiation apparatus is described. It comprises a pressure vessel, a neutronic reactor active portion having a substantially greater height than diameter in the pressure vessel, an annular tank surrounding and spaced from the pressure vessel containing an aqueous indium/sup 1//sup 1//sup 5/ sulfate solution of approximately 600 grams per liter concentration, means for circulating separate coolants through the active portion and the space between the annular tank and the pressure vessel, radiator means adapted to receive the materials to be irradiated, and means for flowing the indium/sup 1//sup 1//sup 5/ sulfate solution through the radiator means.

Leyse, C.F.; Putnam, G.E.

1961-05-01

302

Reactor refueling containment system  

DOEpatents

This report describes a method of refueling a nuclear reactor whereby the drive mechanism is disengaged and removed by activating a jacking mechanism that raises the closure head. The area between the barrier plate and closure head is exhausted through the closure head penetrations. The closure head, upper drive mechanism, and bellows seal are lifted away and transported to a safe area. The barrier plate acts as the primary boundary and each drive and control rod penetration has an elastomer seal preventing excessive tritium gases from escaping. The individual instrumentation plugs are disengaged allowing the corresponding fuel assembly to be sealed and replaced.

Gillett, J.E.; Meuschke, R.E.

1992-12-31

303

Reactor instrumentation renewal of the TRIGA reactor Vienna, Austria  

Microsoft Academic Search

The TRIGA Mark-II reactor at the Atominstitut in Vienna, Austria is replacing its twenty-four year old instrumentation system with a microprocessor based control system supplied by General Atomics. Ageing components, new governmental safety requirements and a need for state of the art instrumentation for training students has spurred the demand for new reactor instrumentation. In Austria a government appointed expert

H. Boeck; H. Weiss; W. E. Hood; W. K. Hyde

1992-01-01

304

Licensed reactor nuclear safety criteria applicable to DOE reactors  

SciTech Connect

The Department of Energy (DOE) Order DOE 5480.6, Safety of Department of Energy-Owned Nuclear Reactors, establishes reactor safety requirements to assure that reactors are sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that adequately protects health and safety and is in accordance with uniform standards, guides, and codes which are consistent with those applied to comparable licensed reactors. This document identifies nuclear safety criteria applied to NRC (Nuclear Regulatory Commission) licensed reactors. The titles of the chapters and sections of USNRC Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants, Rev. 3, are used as the format for compiling the NRC criteria applied to the various areas of nuclear safety addressed in a safety analysis report for a nuclear reactor. In each section the criteria are compiled in four groups: (1) Code of Federal Regulations, (2) US NRC Regulatory Guides, SRP Branch Technical Positions and Appendices, (3) Codes and Standards, and (4) Supplemental Information. The degree of application of these criteria to a DOE-owned reactor, consistent with their application to comparable licensed reactors, must be determined by the DOE and DOE contractor.

Not Available

1991-04-01

305

Fast Reactor Fuel Type and Reactor Safety Performance  

SciTech Connect

Fast Reactor Fuel Type and Reactor Safety Performance R. Wigeland , Idaho National Laboratory J. Cahalan, Argonne National Laboratory The sodium-cooled fast neutron reactor is currently being evaluated for the efficient transmutation of the highly-hazardous, long-lived, transuranic elements that are present in spent nuclear fuel. One of the fundamental choices that will be made is the selection of the fuel type for the fast reactor, whether oxide, metal, carbide, nitride, etc. It is likely that a decision on the fuel type will need to be made before many of the related technologies and facilities can be selected, from fuel fabrication to spent fuel reprocessing. A decision on fuel type should consider all impacts on the fast reactor system, including safety. Past work has demonstrated that the choice of fuel type may have a significant impact on the severity of consequences arising from accidents, especially for severe accidents of low probability. In this paper, the response of sodium-cooled fast reactors is discussed for both oxide and metal fuel types, highlighting the similarities and differences in reactor response and accident consequences. Any fast reactor facility must be designed to be able to successfully prevent, mitigate, or accommodate all consequences of potential events, including accidents. This is typically accomplished by using multiple barriers to the release of radiation, including the cladding on the fuel, the intact primary cooling system, and most visibly the reactor containment building. More recently, this has also included the use of ‘inherent safety’ concepts to reduce or eliminate the potential for serious damage in some cases. Past experience with oxide and metal fuel has demonstrated that both fuel types are suitable for use as fuel in a sodium-cooled fast reactor. However, safety analyses for these two fuel types have also shown that there can be substantial differences in accident consequences due to the neutronic and thermophysical properties of the fuel and their compatibility with the reactor coolant, with corresponding differences in the challenges presented to the reactor developers. Accident phenomena are discussed for the sodium-cooled fast reactor based on the mechanistic progression of conditions from accident initiation to accident termination, whether a benign state is achieved or more severe consequences are expected. General principles connecting accident phenomena and fuel properties are developed from the oxide and metal fuel safety analyses, providing guidelines that can be used as part of the evaluation for selection of fuel type for the sodium-cooled fast reactor.

R. Wigeland; J. Cahalan

2009-09-01

306

PIUS reactor progress summary  

SciTech Connect

Operating excellence is becoming the key concept for assuring the safety of the present generation of light water reactors (LWRs). Human excellence is a scarce commodity, however, and in uncertain supply and of questionable durability. The basis for ABB Atom's long-term development program is a firm conviction that a truly large-scale future expansion of nuclear power must be based on a technology in which safe operation makes much reduced demands on this scarce commodity. The present goal in the United States is to obtain U.S. Nuclear Regulatory Commission design certification by the mid-1990s with lead plant construction closely following. The difference in principle between PIUS and other (existing or proposed) LWR concepts is explained. In other LWR concepts, protection of core integrity, and thereby avoidance of accidents with significant environmental impact, depends on the necessarily uncertain status of safety equipment and on the actions of plant operators. In contrast, in PIUS, core integrity in transients is ensured by the reactor system configuration itself and the resulting self-protective thermohydraulic feedback mechanism. Extended core cooling by submergence in water is assured without any external intervention in spite of any credible structural failures. the safety of an operating core becomes practically invulnerable to human mistake or mischief.

Hannerz, K.; Nilsson, L. (ABB Atom AB-Sweden, Vaesteras (Sweden))

1989-11-01

307

Reactor cavity pool seal  

SciTech Connect

A reactor cavity pool seal is described wherein a removable annular seal plate has an upper surface substantially co-planar with one of a cavity well ledge and a reactor flange upper surface and has a circular edge surface spaced in opposition to a circular face beneath the one of the ledge and flange upper surface, and annular inflatable means are provided in effecting a seal between the spaced circular edge surface and face. The improvement comprises: (a) a flat seal ring on the seal plate, and (b) an annular bearing plate of the same thickness as the seal ring on one of the ledge and flange upper surface, (c) the seal ring and bearing plate defining opposed spaced circular respective inner and outer sealing surfaces, (d) the seal ring being fixed and sealed to the plate and the bearing ring being fixed and sealed to the ione of the ledge and flange upper surface such that the inner and outer sealing surfaces are concentric, (e) the annular inflatable means being located between and operable against the opposed inner and outer sealing surfaces.

Puri, A.

1988-06-28

308

NEUTRONIC REACTOR CORE  

DOEpatents

An improved core for a gas-cooled power reactor which admits gas coolant at high temperatures while affording strong integral supporting structure and efficient moderation of neutrons is described. The multiplicities of fuel elements constituting the critical amassment of fissionable material are supported and confined by a matrix of metallic structure which is interspersed therebetween. Thermal insulation is interposed between substantially all of the metallic matrix and the fuel elements; the insulation then defines the principal conduit system for conducting the coolant gas in heat-transfer relationship with the fuel elements. The metallic matrix itseif comprises a system of ducts through which an externally-cooled hydrogeneous liquid, such as water, is circulated to serve as the principal neutron moderant for the core and conjointly as the principal coolant for the insulated metallic structure. In this way, use of substantially neutron transparent metals, such as aluminum, becomes possible for the supporting structure, despite the high temperatures of the proximate gas. The Aircraft Nuclear Propulsion program's "R-1" reactor design is a preferred embodiment.

Thomson, W.B.; Corbin, A. Jr.

1961-07-18

309

Reactor Physics and Reactor Strategy Investigations into the Fissionable Material Economy of the Thorium and Uranium Cycle in Fast Breeder Reactors and High Temperature Reactors.  

National Technical Information Service (NTIS)

In this work the properties governing the fissionable material economy of the uranium and thorium cycles are investigated for the advanced reactor types currently under development - the fast breeder reactor (FBR) and the high temperature reactor (HTR) - ...

W. M. Schikorr

1980-01-01

310

Overview of the US stellarator reactor study.  

National Technical Information Service (NTIS)

This study, which uses a cost-minimization code that incorporates the ARIES costing and reactor component models with a I-D energy transport calculation, shows that a torsatron reactor could be competitive with a tokamak reactor.

J. F. Lyon K. Gulec R. L. Miller L. El-Guebaly

1993-01-01

311

Overview of the US stellarator reactor study  

NASA Astrophysics Data System (ADS)

This study, which uses a cost-minimization code that incorporates the ARIES costing and reactor component models with a 1-D energy transport calculation, shows that a torsatron reactor could be competitive with a tokamak reactor.

Lyon, J. F.; Gulec, K.; Miller, R. L.; El-Guebaly, L.

1993-10-01

312

National Strategies for Nuclear Power Reactor Development.  

National Technical Information Service (NTIS)

The document assesses the potential for design innovation in three areas of nuclear power plant technology: light water reactor systems; liquid metal reactor systems; and high temperature gas reactor systems. The question of how capital costs scale with u...

R. K. Lester M. J. Driscoll M. W. Golay D. D. Lanning L. M. Lidsky

1985-01-01

313

Materials for passively safe reactors  

Microsoft Academic Search

Future nuclear power capacity will be based on reactor designs that include passive safety features if recent progress in advanced nuclear power developments is realized. There is a high potential for nuclear systems that are smaller and easier to operate than the current generation of reactors, especially when passive or intrinsic characteristics are applied to provide inherent stability of the

Simnad

1993-01-01

314

On Filtration Combustion Reactor Theory  

Microsoft Academic Search

A method for studying high-temperature tubular reactors (combustion reactors) is outlined in the paper. The method is based on the comparison of two characteristic velocities—the reactant supply rate and the combustion wave propagation rate over a moving medium (the kinematic balance method). The possibilities of the method are illustrated by an example of analysis of stationary and nonstationary states of

L. P. YARIN; G. S. SUKHOV

1992-01-01

315

ITER reactor building design study  

Microsoft Academic Search

The International Thermonuclear Experimental Reactor (ITER) is at the midpoint of a two-year conceptual design. The ITER reactor building is a reinforced concrete structure that houses the tokamak and associated equipment and systems and forms a barrier between the tokamak and the external environment. It provides radiation shielding and controls the release of radioactive materials to the environment during both

S. L. Thomson; J. D. Blevins; M. W. Delisle

1989-01-01

316

RADIATION PROTECTION CALCULATIONS FOR REACTORS  

Microsoft Academic Search

Practical shielding calculations for nuclear reactors are described. ; Nuclear radiation involved in reactor shielding and their sources, calculation ; methcds and their basic theories and the nuclear data of materials, which are ; necessary for the calculations, are listed or referred to in the special ; bibliography. The calculations can be made using normal desk calculators. The ; calculations

Lindackers

1960-01-01

317

Fluidized bed nuclear fission reactor  

Microsoft Academic Search

For the further development of nuclear fission reactors, the feasibility of a new concept is evaluated. It concerns a fluidized bed reactor in which carbon particles with a uranium core are fluidized and cooled by a high velocity pressurized helium flow. Nuclear reaction takes place if the bed is in fluidized conditions at a void fraction above 80% and it

T. H. J. J. Van Der Hagen; H. Van Dam

1996-01-01

318

International Research Reactor Decommissioning Project  

Microsoft Academic Search

Many research reactors have been or will be shut down and are candidates for decommissioning. Most of the respective countries neither have a decommissioning policy nor the required expertise and funds to effectively implement a decommissioning project. The IAEA established the Research Reactor Decommissioning Demonstration Project (R²D²P) to help answer this need. It was agreed to involve the Philippine Research

Leonardo Leopando; Ernst Warnecke

2008-01-01

319

India and Fast Breeder Reactors  

Microsoft Academic Search

India has long pursued a fast breeder program, motivated in part by the availability of only poor quality uranium resources within the country. But progress so far has been disappointing, with only one test reactor having been constructed and having a chequered operating history. The larger Prototype Fast Breeder Reactor that is being constructed has a design that compromises safety

M. V. RAMANA

2009-01-01

320

N Reactor secondary loop contamination  

Microsoft Academic Search

N Reactor primary loop water circulates entirely within Zone 1 and the piping is, therefore, heavily shielded. Secondary loop piping crosses the Zone 1 boundaries into areas which may be unshielded and accessible during reactor operation. The leakage of primary loop water to the secondary side of the cooling loop permits contaminated fluid to leave the shielded area. It becomes

Stepnewski

1963-01-01

321

Millisecond chemical reactions and reactors  

Microsoft Academic Search

Short contact time chemical reactors have many features which are very different from conventional packed bed reactors in that temperatures are determined by inlet parameters only, performance is nearly unchanged over wide variations in flow rate, and highly nonequilibrium products can be obtained at high conversions. Chemical reactions occur in regions of large gradients in composition and temperature, so the

Lanny D. Schmidt

2000-01-01

322

Advanced Catalytic Hydrogenation Retrofit Reactor  

Microsoft Academic Search

Industrial hydrogenation is often performed using a slurry catalyst in large stirred-tank reactors. These systems are inherently problematic in a number of areas, including industrial hygiene, process safety, environmental contamination, waste production, process operability and productivity. This program proposed the development of a practical replacement for the slurry catalysts using a novel fixed-bed monolith catalyst reactor, which could be retrofitted

Reinaldo M. Machado

2002-01-01

323

ATFSR: A Small Torsatron Reactor.  

National Technical Information Service (NTIS)

A small (average minor radius anti a approx. = 1 m), moderate-aspect-ratio torsatron reactor based on the Advanced Toroidal Facility (ATF) is proposed as a starting point for improved stellarator reactor designs. The major limitation of the compact size i...

W. A. Houlberg J. T. Lacatski N. A. Uckan

1985-01-01

324

Open issues in reactor dosimetry  

Microsoft Academic Search

The need for more energy in a worldwide scope, as well as the necessity to reduce emission, diversification of energy sources and to preserve the environment equilibrium has renewed the expectations of nuclear energy. Programmes for construction of 3rd and 4th generation reactors, modernization of existing nuclear power plants (NPP), and plant life extension are being developed worldwide. Reactor dosimetry

A. Ballesteros; L. Debarberis; W. Voorbraak; J. Wagemans; P. D’hondt

2010-01-01

325

Activities report in reactor physics  

NASA Astrophysics Data System (ADS)

Radiochemistry radiation measurements and data processing; nuclear biomedical topics; and radioisotope applications were studied. Molecular physics; neutron depolarization; and Mossbauer spectrometry were investigated. Radiation damage in DNA and model systems; photoinduced charge separation; charge separation in semiconductors; Faraday rotation; and instrumentation were studied. Reactor physics statics, dynamics, and noise of reactors; and radiation damage in materials were examined. Radiation protection and dosimetry were investigated.

326

Solvent refined coal reactor quench system  

DOEpatents

There is described an improved SRC reactor quench system using a condensed product which is recycled to the reactor and provides cooling by evaporation. In the process, the second and subsequent reactors of a series of reactors are cooled by the addition of a light oil fraction which provides cooling by evaporation in the reactor. The vaporized quench liquid is recondensed from the reactor outlet vapor stream.

Thorogood, Robert M. (Macungie, PA)

1983-01-01

327

Solvent refined coal reactor quench system  

DOEpatents

There is described an improved SRC reactor quench system using a condensed product which is recycled to the reactor and provides cooling by evaporation. In the process, the second and subsequent reactors of a series of reactors are cooled by the addition of a light oil fraction which provides cooling by evaporation in the reactor. The vaporized quench liquid is recondensed from the reactor outlet vapor stream. 1 fig.

Thorogood, R.M.

1983-11-08

328

Fuel Reformation: Microchannel Reactor Design  

SciTech Connect

Fuel processing is used to extract hydrogen from conventional vehicle fuel and allow fuel cell powered vehicles to use the existing petroleum fuel infrastructure. Kilowatt scale micro-channel steam reforming, water-gas shift and preferential oxida-tion reactors have been developed capable of achieving DOE required system performance metrics. Use of a microchannel design effectively supplies heat to the highly endothermic steam reforming reactor to maintain high conversions, controls the temperature profile for the exothermic water gas shift reactor, which optimizes the overall reaction conversion, and removes heat to prevent the unwanted hydrogen oxidation in the prefer-ential oxidation reactor. The reactors combined with micro-channel heat exchangers, when scaled to a full sized 50 kWe automotive system, will be less than 21 L in volume and 52 kg in weight.

Brooks, Kriston P.; Davis, James M.; Fischer, Christopher M.; King, David L.; Pederson, Larry R.; Rawlings, Gregg C.; Stenkamp, Victoria S.; TeGrotenhuis, Ward E.; Wegeng, Robert S.; Whyatt, Greg A.

2005-09-01

329

Reactor-Produced Medical Radionuclides  

NASA Astrophysics Data System (ADS)

The therapeutic use of radionuclides in nuclear medicine, oncology, and cardiology is the most rapidly growing use of medical radionuclides. Since most therapeutic radionuclides are neutron rich and decay by ?- emission, they are reactor-produced. This chapter deals mainly with production approaches with neutrons. Neutron interactions with matter, neutron transmission and activation rates, and neutron spectra of nuclear reactors are discussed in some detail. Further, a short discussion of the neutron-energy dependence of cross sections, reaction rates in thermal reactors, cross section measurements and flux monitoring, and general equations governing the reactor production of radionuclides are presented. Finally, the chapter is concluded by providing a number of examples encompassing the various possible reaction routes for the production of a number of medical radionuclides in a reactor.

Mirzadeh, S.; Mausner, L. F.; Garland, M. A.

330

Reactor-Produced Medical Radionuclides  

SciTech Connect

The therapeutic use of radionuclides in nuclear medicine, oncology and cardiology is the most rapidly growing use of medical radionuclides. Since most therapeutic radionuclides are neutron rich and decay by beta emission, they are reactor-produced. This chapter deals mainly with production approaches with neutrons. Neutron interactions with matter, neutron transmission and activation rates, and neutron spectra of nuclear reactors are discussed in some detail. Further, a short discussion of the neutron-energy dependence of cross sections, reaction rates in thermal reactors, cross section measurements and flux monitoring, and general equations governing the reactor production of radionuclides are presented. Finally, the chapter is concluded by providing a number of examples encompassing the various possible reaction routes for production of a number of medical radionuclides in a reactor.

Mirzadeh, Saed [ORNL; Mausner, Leonard [Brookhaven National Laboratory (BNL); Garland, Marc A [ORNL

2011-01-01

331

Decontaminating reactor coolant systems  

SciTech Connect

Chemical agents and processes that reduce radioactivity levels where people must work make repairs in the coolant circuits of nuclear power reactors faster and less costly. The low-oxidation-state metal ions (LOMI) chemical process quickly dissolves tough corrosion films that hold radioactive isotopes. Radiation fields on pipe surfaces can be cut by a factor of 20 before repair crews go to work. The two-step LOMI process reagents weaken bonds between oxygen and iron atoms by a spontaneous electron transfer from vanadium to iron. This interrupts the lattice, and iron oxide is easily dissolved by picolinic acid. While cost is the prime factor, since exposure limits must be complied with in any event, safety is the ultimate issue, not only in worker health, but in the reliability and quality of the work done under specific time pressures. 4 references, 5 figures.

Whitaker, R.; Wood, C.

1984-06-01

332

Inherently safe SECURE reactors  

SciTech Connect

Availability of energy for electrification, heating and processes such as water desalination is, although in different proportions, the basis for the development of any country. The role nuclear energy can play depends on the acceptance this power can get, judged on several merits such as economy also with moderate plant sizes (below 600 MWe), safety which is understandable to the layman and which allows location also in densely populated areas, simple operation without heavy demands on the skill of the operation personnel etc. The SECURE reactors, which are designed in different versions to produce energy for district heating, process heat and electricity are all based on the PIUS principle (Process Inherent Ultimate Safety) and are designed to meet the demands mentioned plus others such as modularization, high content of domestic supplies and resistance against severe conditions of natural and human origin.

Skygge, C.O.

1985-01-01

333

REACTOR VIEWING APPARATUS  

DOEpatents

An optical system is presented that is suitable for viewing objects in a region of relatively high radioactivity, or high neutron activity, such as a neutronic reactor. This optical system will absorb neutrons and gamma rays thereby protecting personnel fronm the harmful biological effects of such penetrating radiations. The optical system is comprised of a viewing tube having a lens at one end, a transparent solid member at the other end and a transparent aqueous liquid completely filling the tube between the ends. The lens is made of a polymerized organic material and the transparent solid member is made of a radiation absorbent material. A shield surrounds the tube betwcen the flanges and is made of a gamma ray absorbing material.

Monk, G.S.

1959-01-13

334

GAS COOLED NUCLEAR REACTORS  

DOEpatents

A gas-cooled nuclear reactor consisting of a graphite reacting core and reflector structure supported in a containing vessel is described. A gas sealing means is included for sealing between the walls of the graphite structure and containing vessel to prevent the gas coolant by-passing the reacting core. The reacting core is a multi-sided right prismatic structure having a pair of parallel slots around its periphery. The containing vessel is cylindrical and has a rib on its internal surface which supports two continuous ring shaped flexible web members with their radially innermost ends in sealing engagement within the radially outermost portion of the slots. The core structure is supported on ball bearings. This design permits thermal expansion of the core stracture and vessel while maintainirg a peripheral seal between the tvo elements.

Long, E.; Rodwell, W.

1958-06-10

335

University Reactor Conversion Lessons Learned Workshop for Purdue University Reactor  

SciTech Connect

The Department of Energy’s Idaho National Laboratory, under its programmatic responsibility for managing the University Research Reactor Conversions, has completed the conversion of the reactor at Purdue University Reactor. With this work completed and in anticipation of other impending conversion projects, the INL convened and engaged the project participants in a structured discussion to capture the lessons learned. The lessons learned process has allowed us to capture gaps, opportunities, and good practices, drawing from the project team’s experiences. These lessons will be used to raise the standard of excellence, effectiveness, and efficiency in all future conversion projects.

Eric C. Woolstenhulme; Dana M. Hewit

2008-09-01

336

Licensed reactor nuclear safety criteria applicable to DOE reactors  

SciTech Connect

This document is a compilation and source list of nuclear safety criteria that the Nuclear Regulatory Commission (NRC) applies to licensed reactors; it can be used by DOE and DOE contractors to identify NRC criteria to be evaluated for application to the DOE reactors under their cognizance. The criteria listed are those that are applied to the areas of nuclear safety addressed in the safety analysis report of a licensed reactor. They are derived from federal regulations, USNRC regulatory guides, Standard Review Plan (SRP) branch technical positions and appendices, and industry codes and standards.

Not Available

1993-11-01

337

Reactor vessel cavity seal plate  

SciTech Connect

In a nuclear reactor vessel installation where there is an annular cavity between a reactor vessel having a flange extending radially therefrom and a reactor shield structure, a reactor vessel cavity seal plate, said seal plate is described comprising: (a) an annular plate formed from a plurality of unattached segments positioned adjacent each other, said annular plate having a plurality of ports spaced around its circumference; (b) an inner spacer ring attached to the inner diameter of said annular plate and resting freely upon the reactor vessel flange; (c) an outer spacer ring attached adjacent the outer diameter of said annular plate and resting upon the reactor shield structure; (d) an annular seal formed from a plurality of sections welded together such that said annular seal rests upon said annular plate and extends beyond the inner and outer diameter of said annular plate; (e) an inner seal ring attached to the inner diameter of said annular seal and sealingly attached to the reaction vessel flange; (f) an outer seal ring attached to the outer diameter of said annular seal and sealingly attached to the reactor shield structure; and (g) means for removably covering and sealing the ports in said annular plate.

Behnke, H.W.; Dixon, L.D.; McCann, J.E.

1993-07-27

338

Reactor service life extension program  

SciTech Connect

A review of the Savannah River Site production reactor systems was initiated in 1980 and led to implementation of the Reactor Materials Program in 1984 to assess reactor safety and reactor service life. The program evaluated performance of the reactor tanks, primary coolant piping, and thermal shields, components of welded construction that were fabricated from Type 304 stainless steel. The structural integrity analysis of the primary coolant system has shown that the pressure boundary is not susceptible to gross rupture, including a double ended guillotine break or equivalent large area bank. Residual service life is potentially limited by two material degradation modes, irradiation damage and intergranular stress corrosion cracking. Analysis of the structural integrity of the tanks and piping has shown that continued safe operation of the reactors for several additional decades is not limited by the material performance of the primary coolant system. Although irradiation damage has not degraded material behavior to an unacceptable level, past experience has revealed serious difficulties with repair welding on irradiated stainless steel. Stress corrosion can be mitigated by newly identified limits on impurity concentrations in the coolant water and by stress mitigation of weld residual stresses. Work continues in several areas: the effects of helium on mechanical behavior of irradiated stainless steel; improved weld methods for piping and the reactor tanks; and a surveillance program to track irradiation effects on the tank walls.

Caskey, G.R.; Sindelar, R.L.; Ondrejcin, R.S.; Baumann, E.W.

1990-01-01

339

Reactor service life extension program  

SciTech Connect

A review of the Savannah River Site production reactor systems was initiated in 1980 and led to implementation of the Reactor Materials Program in 1984 to assess reactor safety and reactor service life. The program evaluated performance of the reactor tanks, primary coolant piping, and thermal shields, components of welded construction that were fabricated from Type 304 stainless steel. The structural integrity analysis of the primary coolant system has shown that the pressure boundary is not susceptible to gross rupture, including a double ended guillotine break or equivalent large area bank. Residual service life is potentially limited by two material degradation modes, irradiation damage and intergranular stress corrosion cracking. Analysis of the structural integrity of the tanks and piping has shown that continued safe operation of the reactors for several additional decades is not limited by the material performance of the primary coolant system. Although irradiation damage has not degraded material behavior to an unacceptable level, past experience has revealed serious difficulties with repair welding on irradiated stainless steel. Stress corrosion can be mitigated by newly identified limits on impurity concentrations in the coolant water and by stress mitigation of weld residual stresses. Work continues in several areas: the effects of helium on mechanical behavior of irradiated stainless steel; improved weld methods for piping and the reactor tanks; and a surveillance program to track irradiation effects on the tank walls.

Caskey, G.R.; Sindelar, R.L.; Ondrejcin, R.S.; Baumann, E.W.

1990-12-31

340

Assessment of torsatrons as reactors  

SciTech Connect

Stellarators have significant operational advantages over tokamaks as ignited steady-state reactors because stellarators have no dangerous disruptions and no need for continuous current drive or power recirculated to the plasma, both easing the first wall, blanket, and shield design; less severe constraints on the plasma parameters and profiles; and better access for maintenance. This study shows that a reactor based on the torsatron configuration (a stellarator variant) could also have up to double the mass utilization efficiency (MUE) and a significantly lower cost of electricity (COE) than a conventional tokamak reactor (ARIES-I) for a range of assumptions. Torsatron reactors can have much smaller coil systems than tokamak reactors because the coils are closer to the plasma and they have a smaller cross section (higher average current density because of the lower magnetic field). The reactor optimization approach and the costing and component models are those used in the current stage of the ARIES-I tokamak reactor study. Typical reactor parameters for a 1-GW(e) Compact Torsatron reactor example are major radius R{sub 0} = 6.6-8.8 m, on-axis magnetic field B{sup 0} = 4.8-7.5 T, B{sub max} (on coils) = 16 T, MUE 140-210 kW(e)/tonne, and COE (in constant 1990 dollars) = 67-79 mill/kW(e)h. The results are relatively sensitive to assumptions on the level of confinement improvement and the blanket thickness under the inboard half of the helical windings but relatively insensitive to other assumptions.

Lyon, J.F. [Oak Ridge National Lab., TN (United States); Painter, S.L. [Australian National Univ., Canberra, ACT (Australia)

1992-12-01

341

Research reactor standards and their impact on the TRIGA reactor community  

SciTech Connect

The American Nuclear Society has established a standards committee devoted to writing standards for research reactors. This committee was formed in 1971 and has since that time written over 15 standards that cover all aspects of research reactor operation. The committee has representation from virtually every group concerned with research reactors and their operation. This organization includes University reactors, National laboratory reactors, Nuclear Regulatory commission, Department of Energy and private nuclear companies and insurers. Since its beginning the committee has developed standards in the following areas: Standard for the development of technical specifications for research reactors; Quality control for plate-type uranium-aluminium fuel elements; Records and reports for research reactors; Selection and training of personnel for research reactors; Review of experiments for research reactors; Research reactor site evaluation; Quality assurance program requirements for research reactors; Decommissioning of research reactors; Radiological control at research reactor facilities; Design objectives for and monitoring of systems controlling research reactor effluents; Physical security for research reactor facilities; Criteria for the reactor safety systems of research reactors; Emergency planning for research reactors; Fire protection program requirements for research reactors; Standard for administrative controls for research reactors. Besides writing the above standards, the committee is very active in using communications with the nuclear regulatory commission on proposed rules or positions which will affect the research reactor community.

Richards, W.J. [Argonne National Laboratories (United States)

1980-07-01

342

On reactor type comparisons for the next generation of reactors  

SciTech Connect

In this paper, we present a broad comparison of studies for a selected set of parameters for different nuclear reactor types including the next generation. This serves as an overview of key parameters which provide a semi-quantitative decision basis for selecting nuclear strategies. Out of a number of advanced reactor designs of the LWR type, gas cooled type, and FBR type, currently on the drawing board, the Advanced Light Water Reactors (ALWR) seem to have some edge over other types of the next generation of reactors for the near-term application. This is based on a number of attributes related to the benefit of the vast operating experience with LWRs coupled with an estimated low risk profile, economics of scale, degree of utilization of passive systems, simplification in the plant design and layout, modular fabrication and manufacturing. 32 refs., 1 fig., 3 tabs.

Alesso, H.P.; Majumdar, K.C.

1991-08-22

343

United States Domestic Research Reactor Infrastrucutre TRIGA Reactor Fuel Support  

SciTech Connect

The United State Domestic Research Reactor Infrastructure Program at the Idaho National Laboratory manages and provides project management, technical, quality engineering, quality inspection and nuclear material support for the United States Department of Energy sponsored University Reactor Fuels Program. This program provides fresh, unirradiated nuclear fuel to Domestic University Research Reactor Facilities and is responsible for the return of the DOE-owned, irradiated nuclear fuel over the life of the program. This presentation will introduce the program management team, the universities supported by the program, the status of the program and focus on the return process of irradiated nuclear fuel for long term storage at DOE managed receipt facilities. It will include lessons learned from research reactor facilities that have successfully shipped spent fuel elements to DOE receipt facilities.

Douglas Morrell

2011-03-01

344

Chemistry in water reactors. Reserapport. (Chemistry in water reactors).  

National Technical Information Service (NTIS)

The international conference Chemistry in Water Reactors was arranged in Nice 24-27/04/1994 by the French Nuclear Energy Society. Examples of technical program areas were primary chemistry, operational experience, fundamental studies and new technology. F...

H. P. Hermansson K. Norring

1994-01-01

345

Directions for improved fusion reactors  

SciTech Connect

Conceptual fusion reactor studies over the past 10 to 15 years have projected systems that may be too large, complex, and costly to be of commercial interest. One main direction for improved fusion reactors points towards smaller, higher-power-density approaches. First-order economic issues (i.e., unit direct cost and cost of electricity) are used to support the need for more compact fusion reactors. A generic fusion physics/engineering/costing model is used to provide a quantiative basis for these arguments for specific fusion concepts.

Krakowski, R.A.; Miller, R.L.; Delene, J.G.

1986-01-01

346

Nuclear reactor downcomer flow deflector  

SciTech Connect

A nuclear reactor having a coolant flow deflector secured to a reactor core barrel in line with a coolant inlet nozzle. The flow deflector redirects incoming coolant down an annulus between the core barrel and the reactor vessel. The deflector has a main body with a front side facing the fluid inlet nozzle and a rear side facing the core barrel. The rear side of the main body has at least one protrusion secured to the core barrel so that a gap exists between the rear side of the main body adjacent the protrusion and the core barrel. Preferably, the protrusion is a relief that circumscribes the rear side of the main body.

Gilmore, Charles B. (Greensburg, PA); Altman, David A. (Pittsburgh, PA); Singleton, Norman R. (Murrysville, PA)

2011-02-15

347

The compact liquid metal reactor  

SciTech Connect

As part of the Westinghouse Low Cost Plant Study, a compact 10 MWe sodium cooled reactor design has been developed for remote sites. Thus, design emphasis was placed on modular or factory fabrication and assembly, ease of operation and maintenance, and inherent safety. The reactor is a loop concept consisting of the reactor vessel, pump, evaporator and superheater. Containment is accomplished with a 15 meter cylindrical building 22 meters high. The turbine generator will operate at 480/sup 0/C and 105 kg/cm/sup 2/, while condenser cooling temperature is maintained by a water to air heat exchanger. Overall plant efficiency is expected to be approximately 24%.

Tupper, R.B.; Gallo, F.G.; Lowrie, R.R.; Sievers, R.K.

1984-08-01

348

SP-100 reactor cell activation  

SciTech Connect

There are plans to test the SP-100 space reactor for 2 yr in the test facility shown in Figure 1. The vacuum vessel will be in the reactor experiment (RX) cell surrounded by an inert gas atmosphere. It is proposed that the reactor test cell could contain removable-water- shielding tanks to reduce the residual activation dose rates in the test cell after the tests are completed. This reduction will allow the facility to be considered for other uses after the SP-100 tests are completed. The radiation dose rates in the test cell were calculated for several configurations of water-shielding tanks to help evaluate this concept.

Wilcox, A.D.

1991-09-01

349

Oscillating liquid flow ICF Reactor  

SciTech Connect

Oscillating liquid flow in a falling molten salt inertial confinement fusion reactor is predicted to rapidly clear driver beam paths of residual liquid droplets. Oscillating flow will also provide adequate neutron and x-ray protection for the reactor structure with a short (2-m) fall distance permitting an 8 Hz repetition rate. A reactor chamber configuration is presented with specific features to clear the entire heavy-ion beam path of splashed molten salt. The structural components, including the structure between beam ports, are shielded. 3 refs., 12 figs.

Petzoldt, R.W.

1990-12-14

350

Advanced Test Reactor National Scientific User Facility  

Microsoft Academic Search

The Advanced Test Reactor (ATR), at the Idaho National Laboratory (INL), is a large test reactor for providing the capability for studying the effects of intense neutron and gamma radiation on reactor materials and fuels. The ATR is a pressurized, light-water, high flux test reactor with a maximum operating power of 250 MWth. The INL also has several hot cells

Frances M. Marshall; Jeff Benson; Mary Catherine Thelen

2011-01-01

351

Fast-acting nuclear reactor control device  

Microsoft Academic Search

A fast-acting nuclear reactor control device is described for controlling a safety control rod within the core of a nuclear reactor, the reactor controlled by a reactor control system, the device comprising: a safety control rod drive shaft and an electromagnetic clutch co-axial with the drive shaft operatively connected to the safety control rod for driving and positioning the safety

O. M. Kotlyar; P. B. West

1993-01-01

352

Novel photocatalytic reactor for water purification  

Microsoft Academic Search

A novel photocatalytic reactor design for water treatment is characterized by the use of new extremely narrow diameter lamps, thus allowing for much higher surface area for catalyst coating per unit reactor volume and consequently for much higher specific reactor capacity. Experiments in a reactor containing 21 novel U-shaped lamps coated with catalyst showed a 695% increase in efficiency of

Ajay K. Ray; Antonie A. C. M. Beenackers

1998-01-01

353

LOCA Analysis of Super Fast Reactor  

Microsoft Academic Search

This paper describes loss of coolant accident (LOCA) analyses of the Supercritical-pressure Water-Cooled Fast Reactor (Super Fast Reactor). The features of the Super Fast Reactor are high power density and downward flow cooled fuel channels for the improvement of the economic potential of the Super Fast Reactor with high outlet steam temperature. The LOCA induces large pressure and coolant density

Satoshi IKEJIRI; Chi Young HAN; Yuki ISHIWATARI; Yoshiaki OKA

2011-01-01

354

Upgrade of the Annular Core Pulse Reactor  

Microsoft Academic Search

The Annular Core Pulse Reactor (ACPR) is a TRIGA type reactor which has been in operation at Sandia Laboratories since 1967. The reactor is utilized in a wide variety of experimental programs which include radiation effects, neutron radiography, activation analysis, and fast reactor safety. During the past two years, the ACPR has become an important experimental facility for the United

Reuscher

1976-01-01

355

Low exergy reactor for decentralized energy utilization  

Microsoft Academic Search

A new conceptual reactor named ‘low exergy nuclear reactor (LER)’ was proposed and its possibility was discussed qualitatively. The LER is defined by the reactor that generates low-exergy energy at a temperature near environmental temperature between about 100°C and 300 °C, which is lower than the output temperature of the energy generated by the conventional light water reactors (LWR). The

Yukitaka Kato

2000-01-01

356

Lateral restraint assembly for reactor core  

Microsoft Academic Search

In a nuclear reactor including a reactor vessel defining a shielded core cavity having a reactor core extending vertically along a longitudinal axis and being located internally of the cavity, the reactor core is described which has layers of reflector blocks defining an outer peripheral surface for the core spaced from the vessel and being supported in a manner permitting

W. Gorholt; R. K. Luci

1986-01-01

357

Nuclear reactor degassing method and degassing system  

Microsoft Academic Search

Control rods are inserted into the core of a nuclear reactor in operation to shut down the reactor output. Before completion of entire control rod insertion, a high-temperature coolant flowing in piping for a reactor water clean-up system is sprayed into the space in the upper portion of the reactor vessel. As the space is under negative pressure, oxygen existing

M. Yamamoto; H. Igarashi; S. Mitani; K. Ohsumi; Y. Takashima

1985-01-01

358

Heat dissipating nuclear reactor with metal liner  

Microsoft Academic Search

A nuclear reactor containment is described comprising: reactor vessel means disposed in a metal cavity located partially or completely below the surface of the earth in a cavity, a cast steel containment member partially surrounding the reactor vessel means and having an inner surface conforming in shape to an exterior surface of the reactor vessel means. The cast steel member

E. L. Gluekler; A. Hunsbedt; J. D. Lazarus

1987-01-01

359

Human Factors Aspects of Operating Small Reactors  

Microsoft Academic Search

The nuclear-power community has reached the stage of proposing advanced reactor designs to support power generation for decades to come. They are considering small modular reactors (SMRs) as one approach to meet these energy needs. While the power output of individual reactor modules is relatively small, they can be grouped to produce reactor sites with different outputs. Also, they can

J. M. OHara; J. Higgins; R. Deem; J. Xing; A. DAgostino

2010-01-01

360

Reactor operation environmental information document  

SciTech Connect

This volume is a reactor operation environmental information document for the Savannah River Plant. Topics include meteorology, surface hydrology, transport, environmental impacts, and radiation effects. 48 figs., 56 tabs. (KD)

Bauer, L.R.; Hayes, D.W.; Hunter, C.H.; Marter, W.L.; Moyer, R.A.

1989-12-01

361

Unique features of space reactors  

SciTech Connect

Space reactors are designed to meet a unique set of requirements; they must be sufficiently compact to be launched in a rocket to their operational location, operate for many years without maintenance and servicing, operate in extreme environments, and reject heat by radiation to space. To meet these restrictions, operating temperatures are much greater than in terrestrial power plants, and the reactors tend to have a fast neutron spectrum. Currently, a new generation of space reactor power plants is being developed. The major effort is in the SP-100 program, where the power plant is being designed for seven years of full power, and no maintenance operation at a reactor outlet operating temperature of 1350 K. 8 refs., 3 figs., 1 tab.

Buden, D.

1990-01-01

362

Technical considerations for reactor deactivation.  

National Technical Information Service (NTIS)

This document presents basic technical considerations pertinent to the deactivation of Hanford reactors. These considerations are limited to those items affecting nuclear safety, the capability for reactivation, and radiological hazards. The AEC has annou...

R. E. Baars

1964-01-01

363

Graphite surveillance in N Reactor  

SciTech Connect

Graphite dimensional changes in N Reactor during its 24 yr operating history are reviewed. Test irradiation results, block measurements, stack profiles, top of reflector motion monitors, and visual observations of distortion are described. 18 refs., 14 figs., 1 tab.

Woodruff, E.M.

1991-09-01

364

Advanced Catalytic Hydrogenation Retrofit Reactor  

SciTech Connect

Industrial hydrogenation is often performed using a slurry catalyst in large stirred-tank reactors. These systems are inherently problematic in a number of areas, including industrial hygiene, process safety, environmental contamination, waste production, process operability and productivity. This program proposed the development of a practical replacement for the slurry catalysts using a novel fixed-bed monolith catalyst reactor, which could be retrofitted onto an existing stirred-tank reactor and would mitigate many of the minitations and problems associated with slurry catalysts. The full retrofit monolith system, consisting of a recirculation pump, gas/liquid ejector and monolith catalyst, is described as a monolith loop reactor or MLR. The MLR technology can reduce waste and increase raw material efficiency, which reduces the overall energy required to produce specialty and fine chemicals.

Reinaldo M. Machado

2002-08-15

365

Reactor core isolation cooling system  

DOEpatents

A reactor core isolation cooling system includes a reactor pressure vessel containing a reactor core, a drywell vessel, a containment vessel, and an isolation pool containing an isolation condenser. A turbine is operatively joined to the pressure vessel outlet steamline and powers a pump operatively joined to the pressure vessel feedwater line. In operation, steam from the pressure vessel powers the turbine which in turn powers the pump to pump makeup water from a pool to the feedwater line into the pressure vessel for maintaining water level over the reactor core. Steam discharged from the turbine is channeled to the isolation condenser and is condensed therein. The resulting heat is discharged into the isolation pool and vented to the atmosphere outside the containment vessel for removing heat therefrom.

Cooke, Franklin E. (San Jose, CA)

1992-01-01

366

Ultrasonic inspection of reactor systems  

SciTech Connect

The subject of this presentation is ultrasonic inspection of reactor systems. This paper describes two current programs underway at Savannah River Site which provide state-of-the-art ultrasonic inspections of weld heat-affected zones in the primary cooling loop of the Savannah River Site reactors. It also describes the automated remote inspection equipment being developed and employed; briefly describe the procedures being used; and give you a general idea of the future direction of two major programs: Moderator Piping Inspection Program and the Reactor Tank Wall Weld Inspection Program. The objective of these programs is to provide inspection techniques to more fully determine the condition of the reactor primary system and provide data for prediction of maintenance needs and remaining service life. Detection and sizing of intergranular stress corrosion cracking is the focus of these programs.

Majzlik, E.J. Jr.

1989-01-01

367

Overview of fusion reactor safety  

NASA Astrophysics Data System (ADS)

Use of deuterium-tritium fusion reactors requires examination of several major safety and environmental issues: (1) tritium inventory control; (2) neutron activation of structural materials, fluid streams and reactor hall environment; (3) release of radioactivity from energy sources including lithium spill reactions, superconducting magnet stored energy release, and plasma disruptions; (4) high magnetic and electromagnetic fields associated with fusion reactor superconducting magnets and radio frequency heating devices; and (5) handling and disposal of radioactive waste. Early recognition of potential safety problems with fusion reactors provides the opportunity for improvement in design and materials to eliminate or greatly reduce these problems. With an early start in this endeavor, fusion should be among the lower risk technologies for generation of commercial electrical power.

Cohen, S.; Crocker, J. G.

368

Test Reactor Risk Assessment Methodology.  

National Technical Information Service (NTIS)

A methodology has been developed for the identification of accident initiating events and the fault modeling of systems, including common mode identification, as these methods are applied in overall test reactor risk assessment. The methods are exemplifie...

R. H. Jennings J. K. Rawlins M. E. Stewart

1976-01-01

369

FUEL ELEMENTS FOR NEUTRONIC REACTORS  

DOEpatents

A fuel element for a nuclear reactor is described that consists of a jacket containing a unitary core of fissionable material and a filling of a metal of the group consisting of sodium and sodium-potassium alloys. (AEC)

Foote, F.G.; Jette, E.R.

1963-05-01

370

Nuclear Reactors and Technology; (USA)  

SciTech Connect

Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database (EDB) during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency's Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on EDB and Nuclear Science Abstracts (NSA) database. Current information, added daily to EDB, is available to DOE and its contractors through the DOE integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user's needs.

Cason, D.L.; Hicks, S.C. (eds.)

1991-01-01

371

Combustion synthesis continuous flow reactor  

DOEpatents

The present invention is a reactor for combustion synthesis of inorganic powders. The reactor includes a reaction vessel having a length and a first end and a second end. The reaction vessel further has a solution inlet and a carrier gas inlet. The reactor further has a heater for heating both the solution and the carrier gas. In a preferred embodiment, the reaction vessel is heated and the solution is in contact with the heated reaction vessel. It is further preferred that the reaction vessel be cylindrical and that the carrier gas is introduced tangentially into the reaction vessel so that the solution flows helically along the interior wall of the reaction vessel. As the solution evaporates and combustion produces inorganic material powder, the carrier gas entrains the powder and carries it out of the reactor. 10 figs.

Maupin, G.D.; Chick, L.A.; Kurosky, R.P.

1998-01-06

372

Solid State Reactor Final Report  

SciTech Connect

The Solid State Reactor (SSR) is an advanced reactor concept designed to take advantage of Oak Ridge National Laboratory's (ORNL's) recently developed graphite foam that has enhanced heat transfer characteristics and excellent high-temperature mechanical properties, to provide an inherently safe, self-regulated, source of heat for power and other potential applications. This work was funded by the U.S. Department of Energy's Nuclear Energy Research Initiative (NERI) program (Project No. 99-064) from August 1999 through September 30, 2002. The initial concept of utilizing the graphite foam as a basis for developing an advanced reactor concept envisioned that a suite of reactor configurations and power levels could be developed for several different applications. The initial focus was looking at the reactor as a heat source that was scalable, independent of any heat removal/power conversion process. These applications might include conventional power generation, isotope production and destruction (actinides), and hydrogen production. Having conducted the initial research on the graphite foam and having performed the scoping parametric analyses from neutronics and thermal-hydraulic perspectives, it was necessary to focus on a particular application that would (1) demonstrate the viability of the overall concept and (2) require a reasonably structured design analysis process that would synthesize those important parameters that influence the concept the most as part of a feasible, working reactor system. Thus, the application targeted for this concept was supplying power for remote/harsh environments and a design that was easily deployable, simplistic from an operational standpoint, and utilized the new graphite foam. Specifically, a 500-kW(t) reactor concept was pursued that is naturally load following, inherently safe, optimized via neutronic studies to achieve near-zero reactivity change with burnup, and proliferation resistant. These four major areas of research were undertaken: (1) establishing the design and safety-related basis via neutronic and reactor control assessments with the graphite foam as heat transfer medium; (2) evaluating the thermal performance of the graphite foam for heat removal, reactor stability, reactor operations, and overall core thermal characteristics; (3) characterizing the physical properties of the graphite foam under normal and irradiated conditions to determine any effects on structure, dimensional stability, thermal conductivity, and thermal expansion; and (4) developing a power conversion system design to match the reactor operating parameters.

Mays, G.T.

2004-03-10

373

MARS: Mirror Advanced Reactor Study  

SciTech Connect

A recently completed two-year study of a commercial tandem mirror reactor design (Mirror Advanced Reactor Study (MARS)) is briefly reviewed. The end plugs are designed for trapped particle stability, MHD ballooning, balanced geodesic curvature, and small radial electric fields in the central cell. New technologies such as lithium-lead blankets, 24T hybrid coils, gridless direct converters and plasma halo vacuum pumps are highlighted.

Logan, B.G.

1984-09-10

374

Reactor-vessel-sectioning demonstration  

Microsoft Academic Search

A successful technical demonstration of simulated reactor vessel sectioning was completed using the combined techniques of air arc gouging and flame cutting. A 4-ft x 3-ft x 9-in. thick sample was fabricated of A36 carbon steel to simulate a reactor vessel wall. A 1\\/4-in layer of stainless steel (SS) was tungsten inert gas (TIG)-welded to the carbon steel. Several techniques

Lundgren

1981-01-01

375

In-reactor creep measurements  

Microsoft Academic Search

Creep studies have produced experimental results which are being used for design and performance analyses of fast breeder reactors. These programs enabled the development of experimental methods which have produced in-reactor creep data over a broad range of conditions which include neutron fluences up to 1 x 10²³ n\\/cm² and temperature as high as 750°C. These tests revealed that contrary

E. R. Gilbert; B. A. Chin

1978-01-01

376

[Reactor safety and human failure].  

PubMed

Reactor safety is given by the reliable solution of 3 tasks: on-time shutdown, continuous decay-heat removal, safe containment. After describing the general strategy of their solution even under upset conditions the most important engineered safeguards of pressurized water reactors are summarized. The important problem of human failure is discussed in some more detail. For the example Harrisburg some difficulties, but also some technical countermeasures are illustrated. PMID:537639

Smidt, D

1979-12-01

377

Structural materials for fusion reactors  

Microsoft Academic Search

Fusion Reactors will require specially engineered structural materials, which will simultaneously satisfy the harsh conditions\\u000a such as high thermo mechanical stresses, high heat loads and severe radiation damage without compromising on safety considerations.\\u000a The fundamental differences between fusion and other nuclear reactors arise due to the 14MeV neutronics of structural materials.\\u000a There exists considerable uncertainty in the nuclear data at

P. M. Raole; S. P. Deshpande

2009-01-01

378

Physical security at research reactors  

Microsoft Academic Search

Of the 84 non-power research facilities licensed under 10 CFR Part 50, 73 are active (two test reactors, 68 research reactors and three critical facilities) and are required by 10 CFR Part 73.40 to provide physical protection against theft of SNM and against industrial sabotage. Each licensee has developed a security plan required by 10 CFR Part 50.34(c) to demonstrate

1977-01-01

379

Automatic safety rod for reactors  

DOEpatents

An automatic safety rod for a nuclear reactor containing neutron absorbing material and designed to be inserted into a reactor core after a loss-of-core flow. Actuation is based upon either a sudden decrease in core pressure drop or the pressure drop decreases below a predetermined minimum value. The automatic control rod includes a pressure regulating device whereby a controlled decrease in operating pressure due to reduced coolant flow does not cause the rod to drop into the core.

Germer, John H. (San Jose, CA)

1988-01-01

380

MOLTEN FLUORIDE NUCLEAR REACTOR FUEL  

DOEpatents

Molten-salt reactor fuel compositions consisting of mixtures of fluoride salts are reported. In its broadest form, the composition contains an alkali fluoride such as sodium fluoride, zirconium tetrafluoride, and a uranium fluoride, the latter being the tetrafluoride or trifluoride or a mixture of the two. An outstanding property of these fuel compositions is a high coeffieient of thermal expansion which provides a negative temperature coefficient of reactivity in reactors in which they are used.

Barton, C.J.; Grimes, W.R.

1960-01-01

381

Microchannel Reactors for ISRU Applications  

NASA Astrophysics Data System (ADS)

Affordable planning and execution of prolonged manned space missions depend upon the utilization of local resources and the waste products which are formed in manned spacecraft and surface bases. Successful in-situ resources utilization (ISRU) will require component technologies which provide optimal size, weight, volume, and power efficiency. Microchannel reactors enable the efficient chemical processing of in situ resources. The reactors can be designed for the processes that generate the most benefit for each mission. For instance, propellants (methane) can be produced from carbon dioxide from the Mars atmosphere using the Sabatier reaction and ethylene can be produced from the partial oxidation of methane. A system that synthesizes ethylene could be the precursor for systems to synthesize ethanol and polyethylene. Ethanol can be used as a nutrient for Astrobiology experiments, as well as the production of nutrients for human crew (e.g. sugars). Polyethylene can be used in the construction of habitats, tools, and replacement parts. This paper will present recent developments in miniature chemical reactors using advanced Micro Electro Mechanical Systems (MEMS) and microchannel technology to support ISRU of Mars and lunar missions. Among other applications, the technology has been demonstrated for the Sabatier process and for the partial oxidation of methane. Microchannel reactors were developed based on ceramic substrates as well as metal substrates. In both types of reactors, multiple layers coated with catalytic material are bonded, forming a monolithic structure. Such reactors are readily scalable with the incorporation of extra layers. In addition, this reactor structure minimizes pressure drop and catalyst settling, which are common problems in conventional packed bed reactors.

Carranza, Susana; Makel, Darby B.; Blizman, Brandon; Ward, Benjamin J.

2005-02-01

382

Hydrogen production in solar reactors  

Microsoft Academic Search

The present work summarizes the recent activities of our laboratory in the field of solar-aided hydrogen production with structured monolithic solar reactors. This reactor concept, “transferred” from the well-known automobile exhaust catalytic after-treatment systems, employs ceramic supports optimized to absorb effectively solar radiation and develop sufficiently high temperatures, that are coated with active materials capable to perform\\/catalyze a variety of

Christos C. Agrafiotis; Chrysoula Pagkoura; Souzana Lorentzou; Margaritis Kostoglou; Athanasios G. Konstandopoulos

2007-01-01

383

Reactor for preparing uranium trioxide  

Microsoft Academic Search

Nuclear fuels, such as uranium trioxide, are prepared by thermal decomposition of a nitrate in a fluidized bed reactor. The fluidized bed reactor for preparing uranium trioxide from uranyl nitrate by thermal decomposition has (a) a rectangularly shaped bed which satisfies the critical safety shape of ²³⁵U, (b) plural holes to supply an aqueous solution of uranyl nitrate into the

1983-01-01

384

Chemical reaction and reactor engineering  

SciTech Connect

This book discusses research and design problems, simplifying reactor design considerations such as choice of reactor configuration, optimization, and scaleup, and modern surface analysis techniques for interpreting catalytic phenomena, and deciding on the most advantageous method for the selection, testing, development, and application of catalysts. It also covers how to develop models and formulate design strategies for gas-solid catalytic and noncatalytic reactions, overcoming such obstacles as complex hydrodynamics and inaccurate chemical kinetics in the modeling of fixed-bed catalytic processes.

Carberry, J.J.; Varma, A.

1987-01-01

385

Scaling down trickle bed reactors  

Microsoft Academic Search

The scaling down of trickle bed reactors for catalyst testing in deep hydrodesulphurisation (HDS) is evaluated. A multiphase micro-reactor system has been built specifically for HDS, consisting of a set of six 2mm diameter packed beds with particles of approximately 100?m. To confirm plug-flow behaviour (for integral conversion) and to guarantee the measurement of true kinetics, the hydrodynamics have to

Daniël van Herk; Michiel T. Kreutzer; Michiel Makkee; Jacob A. Moulijn

2005-01-01

386

Directions for improved fusion reactors  

Microsoft Academic Search

Conceptual fusion reactor studies over the past 10 to 15 years have projected systems that may be too large, complex, and costly to be of commercial interest. One main direction for improved fusion reactors points towards smaller, higher-power-density approaches. First-order economic issues (i.e., unit direct cost and cost of electricity) are used to support the need for more compact fusion

R. A. Krakowski; R. L. Miller; J. G. Delene

1986-01-01

387

(Gas-cooled reactor materials)  

SciTech Connect

The meeting of the managers of the US/FRG/CH cooperative subprogram on materials for gas-cooled reactors is described and the status of each of the work packages comprising this cooperation is summarized. Four proposals for new areas of cooperative work were developed. Briefings by sponsoring organizations on the status of gas-cooled reactor programs in the FRG are discussed and experimental efforts being conducted at KFA on materials are reviewed.

Rittenhouse, P.L.

1988-06-30

388

NCSU PULSTAR Reactor instrumentation upgrade  

SciTech Connect

The Nuclear Reactor Program at North Carolina State University initiated an upgrade program at the NCSU PULSTAR Reactor in 1990. Twenty-year-old instrumentation is currently undergoing replacement with solid-state and current technology equipment. The financial assistance from the United States Department of Energy has been the primary source of support. This interim report provides the status of the first two phases of the upgrade program.

Perez, P.B.; Bilyj, S.J.

1993-08-12

389

Reactor shroud joint  

DOEpatents

A shroud for a nuclear reactor is described. In one embodiment, the shroud includes first and second shroud sections, and each shroud section includes a substantially cylindrical main body having a first end and a second end. With respect to each shroud section, a flange is located at the main body first end, and the flange has a plurality of bolt openings therein and a plurality of scalloped regions. The first shroud section is welded to the second shroud section, and at least some of the bolt openings in the first shroud section flange align with respective bolt openings in the second shroud section flange. In the event that the onset of inter-granular stress corrosion cracking is ever detected in the weld between the shroud section, bolts are inserted through bolt openings in the first shroud section flange and through aligned bolt openings the second shroud section flange. Each bolt, in one embodiment, has a shank section and first and second threaded end sections. Nuts are threadedly engaged to the threaded end sections and tightened against the respective flanges. 4 figs.

Ballas, G.J.; Fife, A.B.; Ganz, I.

1998-04-07

390

Novel Catalytic Membrane Reactors  

SciTech Connect

There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

Stuart Nemser, PhD

2010-10-01

391

Solar solids reactor  

DOEpatents

A solar powered kiln is provided, that is of relatively simple design and which efficiently uses solar energy. The kiln or solids reactor includes a stationary chamber with a rearward end which receives solid material to be reacted and a forward end through which reacted material is disposed of, and a screw conveyor extending along the bottom of the chamber for slowly advancing the material between the chamber ends. Concentrated solar energy is directed to an aperture at the forward end of the chamber to heat the solid material moving along the bottom of the chamber. The solar energy can be reflected from a mirror facing at an upward incline, through the aperture and against a heat-absorbing material near the top of the chamber, which moves towards the rear of the chamber to distribute heat throughout the chamber. Pumps at the forward and rearward ends of the chamber pump heated sweep gas through the length of the chamber, while minimizing the flow of gas through an open aperture through which concentrated sunlight is received.

Yudow, Bernard D. (Chicago, IL)

1987-01-01

392

Heterogeneous Transmutation Sodium Fast Reactor  

SciTech Connect

The threshold-fission (fertile) nature of Am-241 is used to destroy this minor actinide by capitalizing upon neutron capture instead of fission within a sodium fast reactor. This neutron-capture and its subsequent decay chain leads to the breeding of even neutron number plutonium isotopes. A slightly moderated target design is proposed for breeding plutonium in an axial blanket located above the active “fast reactor” driver fuel region. A parametric study on the core height and fuel pin diameter-to-pitch ratio is used to explore the reactor and fuel cycle aspects of this design. This study resulted in both non-flattened and flattened core geometries. Both of these designs demonstrated a high capacity for removing americium from the fuel cycle. A reactivity coefficient analysis revealed that this heterogeneous design will have comparable safety aspects to a homogeneous reactor of comparable size. A mass balance analysis revealed that the heterogeneous design may reduce the number of fast reactors needed to close the current once-through light water reactor fuel cycle.

S. E. Bays

2007-09-01

393

Fast Spectrum Molten Salt Reactor Options  

Microsoft Academic Search

During 2010, fast-spectrum molten-salt reactors (FS-MSRs) were selected as a transformational reactor concept for light-water reactor (LWR)-derived heavy actinide disposition by the Department of Energy-Nuclear Energy Advanced Reactor Concepts (ARC) program and were the subject of a preliminary scoping investigation. Much of the reactor description information presented in this report derives from the preliminary studies performed for the ARC project.

Jess C Gehin; David Eugene Holcomb; George F Flanagan; Bruce W Patton; Rob L Howard; Thomas J Harrison

2011-01-01

394

Reactor operations: Brookhaven Medical Research Reactor, Brookhaven High Flux Beam Reactor. Informal report, June 1995  

SciTech Connect

Part one of this report gives the operating history of the Brookhaven Medical Research Reactor for the month of June. Also included are the BMRR technical safety surveillance requirements record and the summary of BMRR irradiations for the month. Part two gives the operating histories of the Brookhaven High Flux Beam Reactor and the Cold Neutron Facility at HFBR for June. Also included are the HFBR technical safety surveillance requirements record and the summary of HFBR irradiations for the month.

NONE

1995-06-01

395

56. ARAII. View inside reactor building looking at SL1 reactor ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

56. ARA-II. View inside reactor building looking at SL-1 reactor vessel. November 19, 1957. Ineel photo no. 57-5864. Photographer: Jack L. Anderson. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

396

98. ARAIII. ML1 reactor pressure vessel is lowered into reactor ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

98. ARA-III. ML-1 reactor pressure vessel is lowered into reactor pit by hoist. July 13, 1963. Ineel photo no. 63-4049. Photographer: Lowin. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

397

SPRAY CALCINATION REACTOR  

DOEpatents

A spray calcination reactor for calcining reprocessin- g waste solutions is described. Coaxial within the outer shell of the reactor is a shorter inner shell having heated walls and with open regions above and below. When the solution is sprayed into the irner shell droplets are entrained by a current of gas that moves downwardly within the inner shell and upwardly between it and the outer shell, and while thus being circulated the droplets are calcined to solids, whlch drop to the bottom without being deposited on the walls. (AEC) H03 H0233412 The average molecular weights of four diallyl phthalate polymer samples extruded from the experimental rheometer were redetermined using the vapor phase osmometer. An amine curing agent is required for obtaining suitable silver- filled epoxy-bonded conductive adhesives. When the curing agent was modified with a 47% polyurethane resin, its effectiveness was hampered. Neither silver nor nickel filler impart a high electrical conductivity to Adiprenebased adhesives. Silver filler was found to perform well in Dow-Corning A-4000 adhesive. Two cascaded hot-wire columns are being used to remove heavy gaseous impurities from methane. This purified gas is being enriched in the concentric tube unit to approximately 20% carbon-13. Studies to count low-level krypton-85 in xenon are continuing. The parameters of the counting technique are being determined. The bismuth isotopes produced in bismuth irradiated for polonium production are being determined. Preliminary data indicate the presence of bismuth207 and bismuth-210m. The light bismuth isotopes are probably produced by (n,xn) reactions bismuth-209. The separation of uranium-234 from plutonium-238 solutions was demonstrated. The bulk of the plutonium is removed by anion exchange, and the remainder is extracted from the uranium by solvent extraction techniques. About 99% of the plutonium can be removed in each thenoyltrifluoroacetone extraction. The viscosity, liquid density, and selfdiffusion coefficient for lanthanum, cerium, and praseodymium were determined. The investigation of phase relationships in the plutonium-cerium-copper ternary system was continued on samples containing a high concentration of copper. These analyses indicate that complete solid solution exists between the binary compounds CeCu/sub 2/ and PuCu/sub 2/, thus forming a quasi-binary system. The study of high temperature ceramic fuel materials has continued with the homogenization and microspheroidization of binary mixtures of plutonium dioxide and zirconium dioxide. Sintering a die-pressed pellet of the mixed powders for one hour at 1450 deg C was not sufficient to completely react the constituents. Complete homogenization was obtained when the pellet was melted in the plasma flame. In addition to the plutonium dioxide-zirconium dioxide microspheres, pure beryllium oxide microspheres were produced in the plasma torch. The electronic distribution functions for the 10% by weight PuO/sub 2/ dissolved in a silicate glass were determined. The plutonium-oxygen interaction at about 2.2A is less than the plutonium-oxygen distance for the 5% PuO/sub 2/. The decrease in the interionic distance is indicative of a stronger plutonium-oxygen association for the more concentrated composition. Potassium plutonium sulfate is being evaluated as a reagent to quantitatively separate plutonium from aqueous solutions. The compound containing two waters of hydration was prepared for thermogravimetric studies using analytically pure plutonium-239. Because of the stability of this compound, it is being evaluated as a calorimetric standard for plutonium-238. (auth)

Johnson, B.M.

1963-08-20

398

FUSED REACTOR FUELS  

DOEpatents

This invention relates to a nuciear reactor fuel composition comprising (1) from about 0.01 to about 50 wt.% based on the total weight of said composition of at least one element selected from the class consisting of uranium, thorium, and plutonium, wherein said eiement is present in the form of at least one component selected from the class consisting of oxides, halides, and salts of oxygenated anions, with components comprising (2) at least one member selected from the class consisting of (a) sulfur, wherein the sulfur is in the form of at least one entity selected irom the class consisting of oxides of sulfur, metal sulfates, metal sulfites, metal halosulfonates, and acids of sulfur, (b) halogen, wherein said halogen is in the form of at least one compound selected from the class of metal halides, metal halosulfonates, and metal halophosphates, (c) phosphorus, wherein said phosphorus is in the form of at least one constituent selected from the class consisting of oxides of phosphorus, metal phosphates, metal phosphites, and metal halophosphates, (d) at least one oxide of a member selected from the class consisting of a metal and a metalloid wherein said oxide is free from an oxide of said element in (1); wherein the amount of at least one member selected from the class consisting of halogen and sulfur is at least about one at.% based on the amount of the sum of said sulfur, halogen, and phosphorus atom in said composition; and wherein the amount of said 2(a), 2(b) and 2(c) components in said composition which are free from said elements of uranium, thorium, arid plutonium, is at least about 60 wt.% based on the combined weight of the components of said composition which are free from said elements of uranium, thorium, and plutonium. (AEC)

Mayer, S.W.

1962-11-13

399

Neutronic reactor thermal shield  

DOEpatents

1. The combination with a plurality of parallel horizontal members arranged in horizontal and vertical rows, the spacing of the members in all horizontal rows being equal throughout, the spacing of the members in all vertical rows being equal throughout; of a shield for a nuclear reactor comprising two layers of rectangular blocks through which the members pass generally perpendicularly to the layers, each block in each layer having for one of the members an opening equally spaced from vertical sides of the block and located closer to the top of the block than the bottom thereof, whereby gravity tends to make each block rotate about the associated member to a position in which the vertical sides of the block are truly vertical, the openings in all the blocks of one layer having one equal spacing from the tops of the blocks, the openings in all the blocks of the other layer having one equal spacing from the tops of the blocks, which spacing is different from the corresponding spacing in the said one layer, all the blocks of both layers having the same vertical dimension or length, the blocks of both layers consisting of relatively wide blocks and relatively narrow blocks, all the narrow blocks having the same horizontal dimension or width which is less than the horizontal dimension or width of the wide blocks, which is the same throughout, each layer consisting of vertical rows of narrow blocks and wide blocks alternating with one another, each vertical row of narrow blocks of each layer being covered by a vertical row of wide blocks of the other layer which wide blocks receive the same vertical row of members as the said each vertical row of narrow blocks, whereby the rectangular perimeters of each block of each layer is completely out of register with that of each block in the other layer.

Lowe, Paul E. (Blue Ash, OH)

1976-06-15

400

Pulsed reactor experiments at Oak Ridge  

SciTech Connect

This paper describes dynamic experiments for 3 pulsed reactors. 1st reactor was pulsed from some average power by rotating a partial Be reflector past an unreflected core face; the other 2 reactors were pulsed by rapid insertion of a fuel rod into the unmoderated and unreflected reactor at essentially zero neutron level with no significant neutron source present. The first reactor was a mockup of an EURATOM design (never constructed) of the proposed SORA Reactor, and the other two were the Health Physics Research Reactor and the Army Pulse Radiation Facility Reactor (APRFR). This paper describes the experiments performed in initial testing of these systems, including destructive tests of APRFR, to set operating limits for this type of reactor in pulsed operation. All the experiments described were performed at the Oak Ridge Critical Experiments Facility.

Mihalczo, J.T.

1994-12-31

401

Automatic reactor protection system tester  

SciTech Connect

In a pressurized water reactor (PWR) plant, the role of protection systems is to continuously monitor reactor physical parameters. If abnormal operating conditions are detected, these systems trigger protective and safeguard actions. On typical 900-MW(electric) PWR units, the reactor protection system consists of more than 30 electrical cabinets per train, i.e., per subsystem part of the safety injection system, each cabinet containing several hundreds of relays. In normal operation, protection systems are on standby. Should one or more of their components fail, this failure could remain undetected. This is why safety authorities require periodic testing of these systems. To eliminate the risk of reactor trip during reactor protection system testing, Framatome has developed a completely automatic tester. Only one technician in the control room is necessary to use this tester, which automatically carries out all the operations previously done manually. For one train, the test lasts only 40 min instead of 10 h. Test sequences are programmed in solid-state memories. The existing relay circuitry of each unit is analyzed beforehand to make any adaptions required by the use of the automatic tester.

Jahnke, S.; Raimondo, E.

1988-01-01

402

International Research Reactor Decommissioning Project  

SciTech Connect

Many research reactors have been or will be shut down and are candidates for decommissioning. Most of the respective countries neither have a decommissioning policy nor the required expertise and funds to effectively implement a decommissioning project. The IAEA established the Research Reactor Decommissioning Demonstration Project (R{sup 2}D{sup 2}P) to help answer this need. It was agreed to involve the Philippine Research Reactor (PRR-1) as model reactor to demonstrate 'hands-on' experience as it is just starting the decommissioning process. Other facilities may be included in the project as they fit into the scope of R{sup 2}D{sup 2}P and complement to the PRR-1 decommissioning activities. The key outcome of the R{sup 2}D{sup 2}P will be the decommissioning of the PRR-1 reactor. On the way to this final goal the preparation of safety related documents (i.e., decommissioning plan, environmental impact assessment, safety analysis report, health and safety plan, cost estimate, etc.) and the licensing process as well as the actual dismantling activities could provide a model to other countries involved in the project. It is expected that the R{sup 2}D{sup 2}P would initiate activities related to planning and funding of decommissioning activities in the participating countries if that has not yet been done.

Leopando, Leonardo [Philippine Nuclear Research Institute, Quezon City (Philippines); Warnecke, Ernst [International Atomic Energy Agency, Vienna (Austria)

2008-01-15

403

SIMPLIFIED SODIUM GRAPHITE REACTOR SYSTEM  

DOEpatents

This patent relates to a nuclear power reactor comprising a reactor vessel, shielding means positioned at the top of said vessel, means sealing said reactor vessel to said shielding means, said vessel containing a quantity of sodium, a core tank, unclad graphite moderator disposed in said tank, means including a plurality of process tubes traversing said tank for isolating said graphite from said sodium, fuel elements positioned in said process tubes, said core tank being supported in spaced relation to the walls and bottom of said reactor vessel and below the level of said sodium, neutron shielding means positioned adjacent said core tank between said core tank and the walls of said vessel, said neutron shielding means defining an annuiar volume adjacent the inside wall of said reactor vessel, inlet plenum means below said core tank for providing a passage between said annular volume and said process tubes, heat exchanger means removably supported from the first-named shielding means and positioned in said annular volume, and means for circulating said sodium over said neutron shielding means down through said heat exchanger, across said inlet plenum and upward through said process tubes, said last-named means including electromagnetic pumps located outside said vessel and supported on said vessel wall between said heat exchanger means and said inlet plenum means. (AEC)

Dickinson, R.W.

1963-03-01

404

Rapid starting methanol reactor system  

DOEpatents

The invention relates to a methanol-to-hydrogen cracking reactor for use with a fuel cell vehicular power plant. The system is particularly designed for rapid start-up of the catalytic methanol cracking reactor after an extended shut-down period, i.e., after the vehicular fuel cell power plant has been inoperative overnight. Rapid system start-up is accomplished by a combination of direct and indirect heating of the cracking catalyst. Initially, liquid methanol is burned with a stoichiometric or slightly lean air mixture in the combustion chamber of the reactor assembly. The hot combustion gas travels down a flue gas chamber in heat exchange relationship with the catalytic cracking chamber transferring heat across the catalyst chamber wall to heat the catalyst indirectly. The combustion gas is then diverted back through the catalyst bed to heat the catalyst pellets directly. When the cracking reactor temperature reaches operating temperature, methanol combustion is stopped and a hot gas valve is switched to route the flue gas overboard, with methanol being fed directly to the catalytic cracking reactor. Thereafter, the burner operates on excess hydrogen from the fuel cells.

Chludzinski, Paul J. (38 Berkshire St., Swampscott, MA 01907); Dantowitz, Philip (39 Nancy Ave., Peabody, MA 01960); McElroy, James F. (12 Old Cart Rd., Hamilton, MA 01936)

1984-01-01

405

Reactor control rod timing system  

DOEpatents

A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.

Wu, Peter T. K. (Clifton Park, NY)

1982-01-01

406

Reactor-vessel-sectioning demonstration.  

SciTech Connect

A successful technical demonstration of simulated reactor vessel sectioning was completed using the combined techniques of air arc gouging and flame cutting. A 4-ft x 3-ft x 9-in. thick sample was fabricated of A36 carbon steel to simulate a reactor vessel wall. A 1/4-in layer of stainless steel (SS) was tungsten inert gas (TIG)-welded to the carbon steel. Several techniques were considered to section the simulated reactor vessel: an air arc gouger was chosen to penetrate the stainless steel, and flame cutting was selected to sever the carbon steel. After the simulated vessel was successfully cut from the SS side, another cut was made, starting from the carbon steel side. This cut was also successful. Cutting from the carbon steel side has the advantages of cost reduction since the air arc gouging step is eliminated and contamination controlled because the molten metal is blown inward.

Lundgren, R.A.

1981-07-01

407

Reactor for preparing uranium trioxide  

SciTech Connect

Nuclear fuels, such as uranium trioxide, are prepared by thermal decomposition of a nitrate in a fluidized bed reactor. The fluidized bed reactor for preparing uranium trioxide from uranyl nitrate by thermal decomposition has (a) a rectangularly shaped bed which satisfies the critical safety shape of /sup 235/U, (b) plural holes to supply an aqueous solution of uranyl nitrate into the reactor, (c) at least two reaction rooms divided by barriers, the bottoms of the barriers being capable of being lifted to control their distance from the floor and a mechanism by which uranium trioxide powder is taken out mainly by being overflowed from the top of the barriers through the reaction rooms, (d) heating means inside and outside of the fluidized-bed, and (e) a head structure which is upwardly V-shaped. Continuous operation can be attained with ease, and uranium trioxide can be made efficiently.

Ueda, K.

1983-08-16

408

Gas Production in Reactor Materials  

SciTech Connect

This paper presents an overview of the principal nuclear reactions that are known to produce hydrogen and helium in irradiated materials and a summary of the comparison of measurements with predictions in various reactors. Hydrogen and helium are produced in all reactor materials by fast neutron reactions which typically have thresholds above 4 MeV. Selected elements also have thermal neutron gas production reactions that can be quite prolific, such as 6Li, 10B, and 14N, and there are a number of elements which produce transmutation products that have high thermal neutron gas production cross sections, most notably 59Ni produced by irradiation of Ni and 65Zn produced by irradiation of Cu or Zn. Since gas production cross sections are isotope-specific, gas production rates can change during irradiation due to transmutation effects or initial rates can be modified by isotopic tailoring of reactor materials.

Greenwood, Lawrence R.

2006-01-18

409

Prospects for toroidal fusion reactors  

SciTech Connect

Work on the International Thermonuclear Experimental Reactor (ITER) tokamak has refined understanding of the realities of a deuterium-tritium (D-T) burning magnetic fusion reactor. An ITER-like tokamak reactor using ITER costs and performance would lead to a cost of electricity (COE) of about 130 mills/kWh. Advanced tokamak physics to be tested in the Toroidal Physics Experiment (TPX), coupled with moderate components in engineering, technology, and unit costs, should lead to a COE comparable with best existing fission systems around 60 mills/kWh. However, a larger unit size, {approximately}2000 MW(e), is favored for the fusion system. Alternative toroidal configurations to the conventional tokamak, such as the stellarator, reversed-field pinch, and field-reversed configuration, offer some potential advantage, but are less well developed, and have their own challenges.

Sheffield, J.; Galambos, J.D.

1994-06-01

410

DOE's way-out reactors  

SciTech Connect

The SP-100 reactor, envisioned long before Star Wars, was to power civilian structures such as the space station and orbiting commercial labs. According to the SDI Organization, it will be the cornerstone for SDI, used as a no-maintenance, general source of energy for the military's infrastructure - weapons scale power will come later. DOE wants to spend $72 in FY 1977 to design and build these reactors. Funding problems with Congress, as well as some of the technology and timetables are discussed here.

Marshall, E.

1986-03-21

411

SP-100 space reactor safety  

SciTech Connect

The SP-100 space reactor power system is being developed to meet the large electrical power requirements of civilian and military missions planned for the 1990's and beyond. It will remove the restrictions on electrical power generation that have tended to limit missions and will enable the fuller exploration and utilization of space. This booklet describes the SP-100 space reactor power system and its development. Particular emphasis is given to safety. The design aand operational features as well as the design and safety review process that will assure that the SP-100 can be launched nd operated safely are described.

Not Available

1987-05-01

412

Space reactor preliminary mechanical design  

SciTech Connect

An analysis was performed on the SABRE reactor space power system to determine the effect of the number and size of heat pipes on the design parameters of the nuclear subsystem. Small numbers of thin walled heat pipes were found to give a lower subsystem mass, but excessive fuel swelling resulted. The SP-100 preliminary design uses 120 heat pipes because of acceptable fuel swelling and a minimum nuclear subsystem mass of 1875 kg. Salient features of the reactor preliminary design are: individual fuel modules, ZrO/sub 2/ block core mounts, bolted collar fuel module restraints, and a BeO central plug.

Meier, K.L.

1983-01-01

413

(Safety related reactor physics calculation for HTGR type reactors)  

SciTech Connect

To address certain needs for validation data for gas-cooled reactors, a series of criticals are being planned at the PROTEUS facility at the Paul Scherrer Institute (PSI) in Wuerenlingen, Switzerland. The International Atomic Energy Agency is establishing a Coordinated Research Program (CRP) to provide a means for interested member countries to participate in the PROTEUS review.

Cleveland, J.C.

1989-10-21

414

Reactivity control assembly for nuclear reactor  

DOEpatents

Reactivity control assembly for nuclear reactor comprises supports stacked above reactor core for holding control rods. Couplers associated with the supports and a vertically movable drive shaft have lugs at their lower ends for engagement with the supports.

Bollinger, Lawrence R. (Schenectady, NY)

1984-01-01

415

Reactor Operations informal monthly report September 1994  

SciTech Connect

This paper presents operations at the MRR and HFBR reactors at Brookhaven National Laboratory for September 1994. Reactor run-times, instrumentation, mechanical maintenance, occurrence reports and safety information are listed. Irradiation summaries are included.

Junker, L.

1994-09-01

416

METALLURGICAL PROBLEMS OF NUCLEAR REACTORS. STRUCTURAL MATERIALS  

Microsoft Academic Search

After a survey of the specifically nuclear data of reactors, the ; different qualities, intrinsic and extrinsic, required for the structural ; materials of reactors are discussed. The effect of radiation on several aspects ; of their behavior is described. (tr-auth);

1958-01-01

417

Small Liquid Metal Cooled Reactor Safety Study.  

National Technical Information Service (NTIS)

The Small Liquid Metal Cooled Reactor Safety Study documents results from activities conducted under Small Liquid Metal Fast Reactor Coordination Program (SLMFR-CP) Agreement, January 2004, between the Central Research Institute of the Electric Power Indu...

A. Minato D. Wade E. Greenspan N. Brown N. Ueda

2005-01-01

418

A GENERAL DESCRIPTION OF THE NRX REACTOR  

Microsoft Academic Search

The NRX reactor structure, equipment, and experimental facilities are described. The information gives only a general knowledge of the reactor and is to serve as an introduction to the NRX Design and Operating Manuals. (D.L.C.)

1961-01-01

419

Equilibrium Field Coil Considerations for Tokamak Reactors.  

National Technical Information Service (NTIS)

Results of studies of the equilibrium field coil system for a variety of tokamak fusion reactor configurations are presented. These results include the determination of the EF coil currents, sizes, Ampere-turns, and stored energies for various reactor siz...

K. Evans D. A. Ehst P. Messerschmidt

1978-01-01

420

Status of the US stellarator reactor study.  

National Technical Information Service (NTIS)

Stellarators have significant operational advantages over tokamaks as ignited steady-state reactors. This scoping study, which uses an integrated cost-minimization code that incorporates costing and reactor component models self-consistently with a 1-D en...

J. F. Lyon K. Gulec R. L. Miller L. El-Guebaly

1994-01-01

421

Fast Reactor Operation in the United States.  

National Technical Information Service (NTIS)

Of the many American facilities dedicated to fast reactor technology, six qualify as liquid-metal-cooled fast reactors. All of these satisfy the following criteria: an unmoderated neutron spectrum, highly enriched fuel material, substantial heat productio...

R. R. Smith D. W. Cissel

1978-01-01

422

BWTR (Boiling Water Tokamak Reactor) Blanket Study.  

National Technical Information Service (NTIS)

The NUWMAK design is a second generation reactor design study. It utilizes the experiences we obtained from UWMAK series designs, combined with recent development in plasma physics and aimed toward a more optimized reactor design. The blanket for NUWMAK i...

D. K. Sze C. W. Maynard I. N. Sviatoslavsky E. T. Cheng C. C. Wang

1978-01-01

423

International Forum for Reactor Aging Management (IFRAM)  

SciTech Connect

The Nuclear Regulatory Commission has undertaken a program to lay the groundwork for defining proactive actions to manage degradation of materials in light water reactors (LWRs). This article discusses the international forum for reactor aging management.

Bond, Leonard J.

2010-11-01

424

Fast Reactor Safety Studies Using VIPER.  

National Technical Information Service (NTIS)

Irradiated fast reactor fuel samples, exposed in a burst reactor such as VIPER to a heating transient, release the fission products accumulated during their original irradiation. By sealing the sample in a capsule, the pressure generated can be measured a...

J. R. Findlay J. H. Tait J. H. Venables M. H. McTaggart M. J. Moreton-Smith

1976-01-01

425

What can Recycling in Thermal Reactors Accomplish?  

SciTech Connect

Thermal recycle provides several potential benefits when used as stop-gap, mixed, or backup recycling to recycling in fast reactors. These three roles involve a mixture of thermal and fast recycling; fast reactors are required to some degree at some time. Stop-gap uses thermal reactors only until fast reactors are adequately deployed and until any thermal-recycle-only facilities have met their economic lifetime. Mixed uses thermal and fast reactors symbiotically for an extended period of time. Backup uses thermal reactors only if problems later develop in the fast reactor portion of a recycling system. Thermal recycle can also provide benefits when used as pure thermal recycling, with no intention to use fast reactors. However, long term, the pure thermal recycling approach is inadequate to meet several objectives.

Steven Piet; Gretchen E. Matthern; Jacob J. Jacobson

2007-09-01

426

What can recycling in thermal reactors accomplish?  

SciTech Connect

Thermal recycle provides several potential benefits when used as stop-gap, mixed, or backup recycling to recycling in fast reactors. These three roles involve a mixture of thermal and fast recycling; fast reactors are required to some degree at some time. Stop-gap uses thermal reactors only until fast reactors are adequately deployed and until any thermal-recycle-only facilities have met their economic lifetime. Mixed uses thermal and fast reactors symbiotically for an extended period of time. Backup uses thermal reactors only if problems later develop in the fast reactor portion of a recycling system. Thermal recycle can also provide benefits when used as pure thermal recycling, with no intention to use fast reactors. However, long term, the pure thermal recycling approach is inadequate to meet several objectives. (authors)

Piet, Steven J.; Matthern, Gretchen E.; Jacobson, Jacob J. [Idaho National Laboratory - INL, 2525 N. Fremont Avenue, Idaho Falls, ID 83415 (United States)

2007-07-01

427

Fusion Reactor Control Study. First Annual Report.  

National Technical Information Service (NTIS)

A study is being conducted of the control and instrumentation requirements of Tokamak experimental power reactors. The project includes the development of digital simulations of Tokamak Experimental Power Reactor (TEPR) behavior. Plasma models for the sim...

T. N. Edelbaum P. A. Madden R. E. Var

1977-01-01

428

Liquid metal cooled nuclear reactor plant system  

DOEpatents

A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting for fuel decay during reactor shutdown, or heat produced during a mishap. The reactor system is enhanced with sealing means for excluding external air from contact with the liquid metal coolant leaking from the reactor vessel during an accident. The invention also includes a silo structure which resists attack by leaking liquid metal coolant, and an added unique cooling means.

Hunsbedt, Anstein (Los Gatos, CA); Boardman, Charles E. (Saratoga, CA)

1993-01-01

429

Integrated modular water reactor (IMR) design  

Microsoft Academic Search

Integrated modular water reactor (IMR) has been developed as one of the advanced small-scale light water reactors, with a thermal output of 1000MW. The IMR adopts natural circulation and self-pressurization in the primary cooling system, and a reactor vessel built-in steam generators. The core design has been performed using the current light water reactor technology. Thermal-hydraulic sensitivity analyses have been

Koki Hibi; Hitoi Ono; Takashi Kanagawa

2004-01-01

430

Transmutation of actinides in power reactors.  

PubMed

Power reactors can be used for partial short-term transmutation of radwaste. This transmutation is beneficial in terms of subsequent storage conditions for spent fuel in long-term storage facilities. CANDU-type reactors can transmute the main minor actinides from two or three reactors of the VVER-1000 type. A VVER-1000-type reactor can operate in a self-service mode with transmutation of its own actinides. PMID:16604724

Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

2005-01-01

431

Relicensing of the MIT Research Reactor  

Microsoft Academic Search

The Massachusetts Institute of Technology (MIT) Research Reactor (MITR) is owned and operated by MIT, a nonprofit university. The current reactor, MITR-II, is a 5-MW, light water-cooled and heavy water-moderated reactor that uses materials test reactor-type fuel. Documents supporting application to the U.S. Nuclear Regulatory Commission (NRC) for relicensing of MITR were submitted in July 1999. A power upgrade from

Lin-Wen Hu; John A. Bernard; Susan Tucker

2000-01-01

432

Designing the Cascade inertial confinement fusion reactor  

SciTech Connect

The primary goal in designing inertial confinement fusion (ICF) reactors is to produce electrical power as inexpensively as possible, with minimum activation and without compromising safety. This paper discusses a method for designing the Cascade rotating ceramic-granule-blanket reactor (Pitts, 1985) and its associated power plant (Pitts and Maya, 1985). Although focus is on the cascade reactor, the design method and issues presented are applicable to most other ICF reactors.

Pitts, J.H.

1987-02-09

433

REACTOR: An Expert System for Diagnosis and Treatment of Nuclear Reactor Accidents  

Microsoft Academic Search

REACTOR is an expert system under development at EG&G Idaho, Inc., that will assist operators in the diagnosis and treatment of nuclear reactor accidents. This paper covers the background of the nuclear industry and why expert system tech- nology may prove valuable in the reactor control room. Some of the basic features of the REACTOR system are discussed, and future

William R. Nelson

1982-01-01

434

Performance of the PRISM (power reactor - innovative, small module) reactor's passive decay heat removal system  

Microsoft Academic Search

The PRISM (power reactor - innovative, small module) modular reactor concept has a totally passive decay heat removal system referred to as the reactor vessel auxiliary cooling system (RVACS) that rejects heat from the reactor by radiation and natural convection of air. The system is inherently reliable and is not subject to the failure modes commonly associated with active cooling

P. M. Magee; A. Hunsbedt

1989-01-01

435

Research reactor standards and their impact on the TRIGA reactor community  

Microsoft Academic Search

The American Nuclear Society has established a standards committee devoted to writing standards for research reactors. This committee was formed in 1971 and has since that time written over 15 standards that cover all aspects of research reactor operation. The committee has representation from virtually every group concerned with research reactors and their operation. This organization includes University reactors, National

1980-01-01

436

MTR BUILDING INTERIOR, TRA603, REACTOR FLOOR. DETAIL OF REACTOR'S SOUTH ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MTR BUILDING INTERIOR, TRA-603, REACTOR FLOOR. DETAIL OF REACTOR'S SOUTH FACE. CAMERA FACING NORTHWESTERLY. INL NEGATIVE NO. HD46-1-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

437

MTR BUILDING INTERIOR, TRA603, REACTOR FLOOR. DETAIL OF REACTOR TEST ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MTR BUILDING INTERIOR, TRA-603, REACTOR FLOOR. DETAIL OF REACTOR TEST HOLE OPENING IN WEST FACE. CAMERA FACING NORTHEAST. INL NEGATIVE NO. HD46-2-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

438

Power Reactor Events and Issues.  

National Technical Information Service (NTIS)

Power Reactor Events and Issues is published by the Office for Analysis and Evaluation of Operational Data (AEOD) of the U.S. Nuclear Regulatory Commission (NRC). The publication presents assessment of selected operating events at U.S. nuclear power plant...

1992-01-01

439

THE FUTURE OF FAST REACTORS  

Microsoft Academic Search

Complete utilization of U in nuclear technology is dependent on the ; breeding of the fuel, this is, however, very difficult to realize with reactors ; operating in the intermediate or thermal neutron range because the breeding ratio ; of the U-- Pu fuel cycle is less than one. Largescale use of U under such ; conditions would simply exhaust

A. I. Leipunskii; O. D. Kazachkovskii; M. S. Pinkhasik

1961-01-01

440

Nozzle for electric dispersion reactor  

DOEpatents

A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 5 figs.

Sisson, W.G.; Harris, M.T.; Scott, T.C.; Basaran, O.A.

1998-06-02

441

High performance light water reactor  

Microsoft Academic Search

The objective of the high performance light water reactor (HPLWR) project is to assess the merit and economic feasibility of a high efficiency LWR operating at thermodynamically supercritical regime. An efficiency of approximately 44% is expected. To accomplish this objective, a highly qualified team of European research institutes and industrial partners together with the University of Tokyo is assessing the

D. Squarer; T. Schulenberg; D. Struwe; Y. Oka; D. Bittermann; N. Aksan; C. Maraczy; R. Kyrki-Rajamäki; A. Souyri; P. Dumaz

2003-01-01

442

DOE's Way-Out Reactors  

Microsoft Academic Search

The SP-100 reactor, envisioned long before Star Wars, was to power civilian structures such as the space station and orbiting commercial labs. According to the SDI Organization, it will be the cornerstone for SDI, used as a no-maintenance, general source of energy for the military's infrastructure - weapons scale power will come later. DOE wants to spend $72 in FY

Eliot Marshall

1986-01-01

443

REACTOR CONDITIONS FOR MAGNOX ELEMENTS  

Microsoft Academic Search

The progress made in demonstrating the endurance capability of natural ; uranium, magnesium-alloy-clad fuel elements is reviewed. The program of devising ; and proving metallurgical and manufacturing modifications to the standard design ; of Calder Hall fuel elementa is described. The difference in fuel elements for ; power reactors and Calder Hall fuel elements is discussed. Irradiation testing ; and

Kavanagh

1962-01-01

444

Nozzle for electric dispersion reactor  

DOEpatents

A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

Sisson, Warren G. (Oak Ridge, TN); Basaran, Osman A. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN)

1998-01-01

445

Nozzle for electric dispersion reactor  

DOEpatents

A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

Sisson, Warren G. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN)

1998-01-01

446

Nozzle for electric dispersion reactor  

DOEpatents

A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

Sisson, Warren G. (Oak Ridge, TN); Basaran, Osman A. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN)

1995-01-01

447

Nozzle for electric dispersion reactor  

DOEpatents

A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

Sisson, Warren G. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN)

1996-01-01

448

NBS reactor: Summary of activities  

NASA Astrophysics Data System (ADS)

Programs which depend on the NBS reactor were summarized from July 1981 through June 1982. The programs range from the use of neutron beams to study the structure and dynamics of materials through nuclear physics and neutron standards to sample irradiations for activation analysis, isotope production, radiation effects studies, neutron radiography, and nondestructive evaluation.

Shorten, F. J.

1983-06-01

449

NBS reactor: Summary of activities  

Microsoft Academic Search

Programs which depend on the NBS reactor were summarized from July 1981 through June 1982. The programs range from the use of neutron beams to study the structure and dynamics of materials through nuclear physics and neutron standards to sample irradiations for activation analysis, isotope production, radiation effects studies, neutron radiography, and nondestructive evaluation.

F. J. Shorten

1983-01-01

450

NBS reactor: Summary of activities  

Microsoft Academic Search

Programs which depend on the NBS reactor are summarized for the period from July 1977 through June 1978. Topics covered include the use of neutron beams to study the structure and dynamics of materials through nuclear physics and neutron standards, sample irradiations for activation analysis, isotope production, radiation effects studies, neutron radiography, and nondestructive evaluations.

F. J. Shorten

1979-01-01

451

Russian RBMK reactor design information.  

National Technical Information Service (NTIS)

This document concerns the systems, design, and operations of the graphite-moderated, boiling, water-cooled, channel-type (RBMK) reactors located in the former Soviet Union (FSU). The Russian Academy of Sciences Nuclear Safety Institute (NSI) in Moscow, R...

1993-01-01

452

Nozzle for electric dispersion reactor  

DOEpatents

A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 5 figs.

Sisson, W.G.; Harris, M.T.; Scott, T.C.; Basaran, O.A.

1996-04-02

453

Integral data for fast reactors  

Microsoft Academic Search

Requirements at Argonne National Laboratory to establish the best estimates and uncertainties for LMR design parameters have lead to an extensive evaluation of the available critical experiment database. Emphasis has been put upon selection of a wide range of cores, including both benchmark, assemblies covering a range of spectra and compositions and power reactor mock-up assemblies with diverse measured parameters.

P. J. Collins; W. P. Poenitz; H. F. McFarlane

1988-01-01

454

Immobilized enzyme reactors in proteomics  

Microsoft Academic Search

Fast, efficient characterization of proteins is becoming one of the hottest topics in the bioanalytical community, especially for large-scale proteomic studies. As an attractive approach, protein digestion by enzymes supported on various matrices (referred to as immobilized enzyme reactors, IMERs) has recently attracted much attention.In this article, we present a critical overview of some highly efficient IMERs and related analytical

Junfeng Ma; Lihua Zhang; Zhen Liang; Yichu Shan; Yukui Zhang

2011-01-01

455

Silica-Immobilized Enzyme Reactors  

Microsoft Academic Search

Recent studies have demonstrated the applicability and versatility of immobilized enzyme reactors (IMERs) for chemical and biochemical synthesis and analysis. The majority of IMER systems rely on enzymes immobilized to packed matrices within flow-through devices. This review focuses primarily on the use of silica as a support for enzyme immobilization and specific applications of the resulting silica-based IMERs. A number

Heather R. Luckarift

2008-01-01

456

Liquid metal fusion reactor systems  

Microsoft Academic Search

The main conceptual designs of liquid metal blanket, methods of pressure drop decrease in the strong magnetic field of the fusion reactor are being discussed. Special features of the flows of electrically conductive fluids in the strong magnetic fields (N? M? 1) are examined. The approximate limits of the transition to the linear (Stokes) flow in the characteristic elements of

B. G. Karasev; A. V. Tananaev

1990-01-01

457

INVESTIGATIONS WITH MERCURY FLOW REACTOR  

EPA Science Inventory

The objective of the research performed in the Mercury Flow Reactor is to investigate short residence-time (seconds) adsorption of mercury species using different sorbents. Emphasis is placed on the effects of mercury concentration, flow rates, reaction temperatures, exposure ti...

458

PERTURBATION THEORY AND REACTOR ANALYSIS  

Microsoft Academic Search

Approximate solutions to many problems of interest in reactor design are ; often obtained by means of first-order perturbation theory. The utility of such ; calculations is assessed herein, and it is observed that higher-order ; calculations are essential to meaningful results. A method which has the virtue ; of rapid convergence and simplicity of form, is chosen from among

E. Blue; J. W. Zink

1959-01-01

459

NUCLEAR FUELS FOR POWER REACTORS  

Microsoft Academic Search

The theoretical and practical requirements of power reactor fuels are ; reviewed critically. The factors considered include the nuclear properties ; necessary for a sustained chain reaction, such as the concentration of ; fissionable and neutron-absorbing elements in the material, the heat-transfer ; parameters, including heat conductivity and refractoriness, chemical stability ; and corrosion resistance, thermal shock resistance, and radiation

Mirion

1962-01-01

460

Turbulence may sink titanic reactor  

SciTech Connect

The $10 billion International Thermonuclear Experimental Reactor project is meant to show that fusion is a practical energy source, but a new set of calculations says ITER will fizzle. This article describes the expectations and the projections about its future, as well as the challenges recently mounted using new calculations. 3 figs.

Glanz, J.

1996-12-06

461

Seismic Testing of Reactor Components.  

National Technical Information Service (NTIS)

This report is the final report on the seismic testing of reactor components conducted since 1977 with opening of the vibration laboratory at KAERI. In 1979, forced vibration testing of Wolsung-1 steam generator model using sine dwell and white nosie rand...

B. K. Kim S. H. Park I. K. Kim B. S. Kim Y. M. Kim

1980-01-01

462

Nuclear reactor safety heat transfer  

Microsoft Academic Search

Nuclear Reactor Safety Heat Transfer is presented in five major sections.The first section presents the background material placing nuclear power in perspective. Starting with a historical overview, followed by fundamental concepts of nuclear energy and the philosphy of risk, the first three chapters: give the reader a brief but thorough introduction to nuclear power generation; describe the different types of

O. C. Jr

1981-01-01

463

FUZZY MODELLING APPLIED TO AN UASB REACTOR  

Microsoft Academic Search

High-rate anaerobic systems, such as the upflow anaerobic sludge blanket (UASB) reactors, are widely used in municipal and industrial wastewater treatment. Even though UASB reactors have several operational advantages, many industries are still reluctant to use them due to the fact that these reactors usually demand constant monitoring of effluent quality, excess sludge discharge and biogas production rate. Otherwise, they

R. M. Borges; C. J. Munaro; R. F. Gonçalves

464

Control Rod Malfunction at the NRAD Reactor  

Microsoft Academic Search

The neutron Radiography Reactor (NRAD) is a training, research, and isotope (TRIGA) reactor located at the INL. The reactor is normally shut down by the insertion of three control rods that drop into the core when power is removed from electromagnets. During a routine shutdown, indicator lights on the console showed that one of the control rods was not inserted.

Thomas L. Maddock

2010-01-01

465

Reactor noise in accelerator driven systems  

Microsoft Academic Search

Reactor noise methods have long been used for measuring reactor kinetics parameters in low power critical and sub critical reactors. The recent interest in accelerator driven sub critical systems (ADS) and the necessity of monitoring their degree of sub criticality has created a renewed interest in these methods. In this paper we derive formulae for interpreting some of the classical

S. B. Degweker

2003-01-01

466

Optimal temperature profile in methanol synthesis reactor  

Microsoft Academic Search

An optimal temperature profile is determined for a methanol synthesis reactor of LURGI type. The temperature profile is estimated so that methanol production rate in the reactor outlet will be maximized. First, the reactor is simulated based on heterogeneous one- and two-dimensional models. The comparison of the simulation results and plant data shows that the heterogeneous one-dimensional model can reliably

A. Jahanmiri; R. Eslamloueyan

2002-01-01

467

Research Program of a Super Fast Reactor  

Microsoft Academic Search

Research program of a supercritical-pressure light water cooled fast reactor (Super Fast Reactor) is funded by MEXT (Ministry of Education, Culture, Sports, Science and Technology) in December 2005 as one of the research programs of Japanese NERI (Nuclear Energy Research Initiative). It consists of three programs. (1) development of Super Fast Reactor concept; (2) thermal-hydraulic experiments; (3) material developments. The

Yoshiaki Oka; Yuki Ishiwatari; Jie Liu; Takayuki Terai; Shinya Nagasaki; Yusa Muroya; Hiroaki Abe; Hideo Mori; Masato Akiba; Hajime Akimoto; Keisuke Okumura; Naoaki Akasaka; Shoji GOTO

2006-01-01

468

HIGH TEMPERATURE THERMODYNAMIC PROPERTIES OF REACTOR MATERIALS  

Microsoft Academic Search

High-temperature thermodynamic properties of reactor materials are ; important to chemical engineers, ceramists, metallurgists, and reactor engineers ; in developing pyromnetallurgical processing procedures, fabricating fuel ; assemblies, and designing high temperature reactors. A critical evaluation and ; discussion is to be presented so that reliable free energies and phase diagrams ; if possible are available to enable one to predict

R. J. Ackermann; R. J. Thorn

1958-01-01

469

METHANE COUPLING USING CATALYTIC MEMBRANE REACTORS  

Microsoft Academic Search

The purpose of this review article is to provide readers with an extensive account on methane-coupling reactions performed in membrane reactors available in literature up to 2000. The principles, advantages or disadvantages, and crucial problems of all kinds of membrane reactors used in methane coupling are discussed. Some areas such as solid oxide membrane reactors for methane oxidative coupling are

Shaomin Liu; Xiaoyao Tan; K. Li; R. Hughes

2001-01-01

470

Intrinsically secure fast reactors with dense cores  

Microsoft Academic Search

Secure safety, resistance to weapons material proliferation and problems of long-lived wastes remain the most important “painful points” of nuclear power.Many innovative reactor concepts have been developed aimed at a radical enhancement of safety. The promising potential of innovative nuclear reactors allows for shifting accents in current reactor safety “strategy” to reveal this worth. Such strategy is elaborated focusing on

Igor Slessarev

2007-01-01

471

THE EXPERIMENTAL GAS-COOLED REACTOR  

Microsoft Academic Search

The Experimental Gas-Cooled Reactor, designated EGCR, is currently being ; constructed in Oak Ridge, Tennessee, under the direction of the U. S. Atomic ; Energy Commission. The reactor will be a dual purpose plant in that it has been ; designed to provide for both power demonstration and experimental testing. It is ; a helium-cooled, graphite-moderated reactor, using high performance

W. D. Manly; J. H. Coobs

1962-01-01

472

Selection of catalysts and reactors for hydroprocessing  

Microsoft Academic Search

The performance of hydroprocessing units can be influenced by the selection of the catalysts and the type of reactor to suit a particular feed. Catalysts ranging widely in chemical composition and physical properties are available commercially. New catalysts have been developed for deep hydrodesulfurization and aromatics hydrogenation. Several types of reactors are proven commercially as well. The catalysts and reactors

Edward Furimsky

1998-01-01

473

Ebullated bed reactor modeling for residue conversion  

Microsoft Academic Search

Ebullated bed reactors are suitable for deeply converting heavy feedstocks such as residues. In this study, a dynamic reactor model is developed taking into account hydrodynamics, catalytic and thermal kinetics. First, a validation of the hydrodynamic model is performed on a bench scale reactor using a radioactive tracer test for residence time distribution measurements under industrial conditions. In a second

Jean-Marc Schweitzer; Stéphane Kressmann

2004-01-01

474

Fusion reactors as a future energy source  

Microsoft Academic Search

A detailed update of fusion research concepts is given. Discussions are given for the following areas: (1) the magnetic confinement principle, (2) UWMAK I: conceptual design for a fusion reactor, (3) the inertial confinement principle, (4) the laser fusion power plant, (5) electron-induced fusion, (6) the long-term development potential of fusion reactors, (7) the symbiosis between fusion and fission reactors,

W. Seifritz

1975-01-01

475

Studies of conceptual spheromak fusion reactors  

Microsoft Academic Search

Preliminary design studies are carried out for a spheromak fusion reactor. Simplified circuit theory is applied to obtain the characteristic relations among various parameters of the spheromak configuration for an aspect ratio of A ? 1.6. These relations are used to calculate the parameters for the conceptual designs of three types of fusion reactor: (1) the DT reactor with two-component-type

M. Katsurai; M. Yamada

1982-01-01

476

Figure of merit of magnetic fusion reactor  

Microsoft Academic Search

This paper proposes and defines ''the figure of merit of fusion reactor'' F which can indicate the economics of fusion reactor comparatively simply and easily by using every important evaluation factor. An attempt to express it synthetically in a numerical formula as to magnetic confined fusion reactor is made. By means of this evaluation formula F, some evaluation studies are

Kazawa

1986-01-01

477

Irradiation Facilities at the Advanced Test Reactor  

SciTech Connect

The Advanced Test Reactor (ATR) is the third generation and largest test reactor built in the Reactor Technology Complex (RTC – formerly known as the Test Reactor Area), located at the Idaho National Laboratory (INL), to study the effects of intense neutron and gamma radiation on reactor materials and fuels. The RTC was established in the early 1950s with the development of the Materials Testing Reactor (MTR), which operated until 1970. The second major reactor was the Engineering Test Reactor (ETR), which operated from 1957 to 1981, and finally the ATR, which began operation in 1967 and will continue operation well into the future. These reactors have produced a significant portion of the world’s data on materials response to reactor environments. The wide range of experiment facilities in the ATR and the unique ability to vary the neutron flux in different areas of the core allow numerous experiment conditions to co-exist during the same reactor operating cycle. Simple experiments may involve a non-instrumented capsule containing test specimens with no real-time monitoring or control capabilities1. More sophisticated testing facilities include inert gas temperature control systems and pressurized water loops that have continuous chemistry, pressure, temperature, and flow control as well as numerous test specimen monitoring capabilities. There are also apparatus that allow for the simulation of reactor transients on test specimens.

S. Blaine Grover

2005-12-01

478

A Fail-Safe Reactor Safety System  

Microsoft Academic Search

A highly reliable solid state reactor safety system operated in dynamic mode is described. Direct current signals from detectors for reactor control are converted to pulse signals, which are continuously generated by the circuit until some abnormal condition occurs.The design and construction of several kinds of logic circuits used for reactor control are explained in detail. The fail-safe property of

Tornio TSUNODA; Seiichiro GOTOH; Eiji SUZUKI

1967-01-01

479

The temperature scanning reactor II: Theory of operation  

Microsoft Academic Search

The theoretical development of the defining equations for the Temperature Scanning methodology and for operation of Temperature Scanning Reactors is presented. Batch Reactors, Stream Swept Reactors, Continuous Stirred Tank Reactors and Plug Flow Reactors are considered in detail. For all these reactor types, we show that rates of reaction, with their associated temperatures and levels of conversion, can be measured

N. M. Rice; B. W. Wojciechowski

1997-01-01

480

STEAM STIRRED HOMOGENEOUS NUCLEAR REACTOR  

DOEpatents

A homogeneous nuclear reactor utilizing a selfcirculating liquid fuel is described. The reactor vessel is in the form of a vertically disposed tubular member having the lower end closed by the tube walls and the upper end closed by a removal fianged assembly. A spherical reaction shell is located in the lower end of the vessel and spaced from the inside walls. The reaction shell is perforated on its lower surface and is provided with a bundle of small-diameter tubes extending vertically upward from its top central portion. The reactor vessel is surrounded in the region of the reaction shell by a neutron reflector. The liquid fuel, which may be a solution of enriched uranyl sulfate in ordinary or heavy water, is mainiained at a level within the reactor vessel of approximately the top of the tubes. The heat of the reaction which is created in the critical region within the spherical reaction shell forms steam bubbles which more upwardly through the tubes. The upward movement of these bubbles results in the forcing of the liquid fuel out of the top of these tubes, from where the fuel passes downwardly in the space between the tubes and the vessel wall where it is cooled by heat exchangers. The fuel then re-enters the critical region in the reaction shell through the perforations in the bottom. The upper portion of the reactor vessel is provided with baffles to prevent the liquid fuel from splashing into this region which is also provided with a recombiner apparatus for recombining the radiolytically dissociated moderator vapor and a control means.

Busey, H.M.

1958-06-01

481

Control of reactor coolant flow path during reactor decay heat removal  

DOEpatents

An improved reactor vessel auxiliary cooling system for a sodium cooled nuclear reactor is disclosed. The sodium cooled nuclear reactor is of the type having a reactor vessel liner separating the reactor hot pool on the upstream side of an intermediate heat exchanger and the reactor cold pool on the downstream side of the intermediate heat exchanger. The improvement includes a flow path across the reactor vessel liner flow gap which dissipates core heat across the reactor vessel and containment vessel responsive to a casualty including the loss of normal heat removal paths and associated shutdown of the main coolant liquid sodium pumps. In normal operation, the reactor vessel cold pool is inlet to the suction side of coolant liquid sodium pumps, these pumps being of the electromagnetic variety. The pumps discharge through the core into the reactor hot pool and then through an intermediate heat exchanger where the heat generated in the reactor core is discharged. Upon outlet from the heat exchanger, the sodium is returned to the reactor cold pool. The improvement includes placing a jet pump across the reactor vessel liner flow gap, pumping a small flow of liquid sodium from the lower pressure cold pool into the hot pool. The jet pump has a small high pressure driving stream diverted from the high pressure side of the reactor pumps. During normal operation, the jet pumps supplement the normal reactor pressure differential from the lower pressure cold pool to the hot pool. Upon the occurrence of a casualty involving loss of coolant pump pressure, and immediate cooling circuit is established by the back flow of sodium through the jet pumps from the reactor vessel hot pool to the reactor vessel cold pool. The cooling circuit includes flow into the reactor vessel liner flow gap immediate the reactor vessel wall and containment vessel where optimum and immediate discharge of residual reactor heat occurs.

Hunsbedt, Anstein N. (Los Gatos, CA)

1988-01-01

482

Commercialized fast reactor cycle systems and reactor core performance of the promising fast reactors  

Microsoft Academic Search

The Feasibility Study on Commercialized Fast Reactor (FR) Cycle Systems is under progress in order to propose prominent FR cycle systems that will respond to the diverse needs of society in the future. The design studies on various FR system concepts have been achieved and then the evaluations of potential to achieve the development targets have been also carried out.

Shoji Kotake; Yoshihiko Sakamoto; Yutaka Sagayama

2005-01-01

483

Reactor monitoring and safeguards using antineutrino detectors  

SciTech Connect

Nuclear reactors have served as the antineutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these very weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Measurements made with antineutrino detectors could therefore offer an alternative means for verifying the power history and fissile inventory of a reactors, as part of International Atomic Energy Agency (IAEA) and other reactor safeguards regimes. Several efforts to develop this monitoring technique are underway across the globe.

Bowden, N S

2008-09-07

484

Reactor monitoring and safeguards using antineutrino detectors  

NASA Astrophysics Data System (ADS)

Nuclear reactors have served as the antineutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these very weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Measurements made with antineutrino detectors could therefore orer an alternative means for verifying the power history and fissile inventory of a reactors, as part of International Atomic Energy Agency (IAEA) and other reactor safeguards regimes. Several erorts to develop this monitoring technique are underway across the globe.

Bowden, N. S.

2008-11-01

485

Refurbishment of existing research reactors for BNCT  

SciTech Connect

Some research reactors have been selected for the development of boron neutron capture therapy (BNCT) in the United States like the Massachusetts Institute of Technology research reactor, the University of Missouri research reactor 2 or the Brookhaven Medical Research Reactor, among others. These reactors have received excellent analyses and designs to accommodate extremely optimized beam shaping assemblies (BSAs) for the proper tuning of neutron spectra and absorption of undesired particles such as photons and fast neutrons. Due to the importance of BNCT in these facilities, the physicists and engineers have used many degrees of freedom for the optimization process.

Jatuff, F.E.; Gessaghi, V. [INVAP S.E., de Bariloche (Argentina)

1997-12-01

486

Reactor assessments of advanced bumpy torus configurations  

SciTech Connect

Recently, several configurational approaches and concept improvement schemes were introduced for enhancing the performance of the basic ELMO Bumpy Torus (EBT) concept and for improving its reactor potential. These configurations include planar racetrack and square geometries, Andreoletti coil systems, and bumpy torus-stellarator hybrids (which include twisted racetrack and helical axis stellarator-snakey torus). Preliminary evaluations of reactor implications of each of these configurations have been carried out based on magnetics (vacuum) calculations, transport and scaling relationships, and stability properties. Results indicate favorable reactor projections with a significant reduction in reactor physical size as compared to conventional EBT reactor designs carried out in the past.

Uckan, N.A.; Owen, L.W.; Spong, D.A.; Miller, R.L.; Ard, W.B.; Pipkins, J.F.; Schmitt, R.J.

1983-01-01

487

Decommissioning a nuclear reactor. [Water Boiler Reactor Project  

SciTech Connect

The process of decommissioning a facility such as a nuclear reactor or reprocessing plant presents many waste management options and concerns. Waste minimization is a primary consideration, along with protecting a personnel and the environment. Waste management is complicated in that both radioactive and chemical hazardous wastes must be dealt with. This paper presents the general decommissioning approach of a recent project at Los Alamos. Included are the following technical objectives: site characterization work that provided a thorough physical, chemical, and radiological assessment of the contamination at the site; demonstration of the safe and cost-effective dismantlement of a highly contaminated and activated nuclear-fuelded reactor; and techniques used in minimizing radioactive and hazardous waste. 12 figs.

Montoya, G.M.

1991-01-01

488

Reactor Noise Analysis of Swimming Pool Type Reactor  

Microsoft Academic Search

Reactor power frequency spectrum measurements at various power levels (0.2 W, 1 W, 5 W, 100 W, 500 W, 5 kW and 100 kW) were made with HTR** (swimming-pool type). A low frequency AC amplifier, a magnetic tape recorder, a frequency selective amplifier with twin-T filters, a multiplier, and an integrator were used. Speed-up and speed-down techniques of tape recorder

Shuji YAMADA

1964-01-01

489

Research Program of a Super Fast Reactor  

SciTech Connect

Research program of a supercritical-pressure light water cooled fast reactor (Super Fast Reactor) is funded by MEXT (Ministry of Education, Culture, Sports, Science and Technology) in December 2005 as one of the research programs of Japanese NERI (Nuclear Energy Research Initiative). It consists of three programs. (1) development of Super Fast Reactor concept; (2) thermal-hydraulic experiments; (3) material developments. The purpose of the concept development is to pursue the advantage of high power density of fast reactor over thermal reactors to achieve economic competitiveness of fast reactor for its deployment without waiting for exhausting uranium resources. Design goal is not breeding, but maximizing reactor power by using plutonium from spent LWR fuel. MOX will be the fuel of the Super Fast Reactor. Thermal-hydraulic experiments will be conducted with HCFC22 (Hydro chlorofluorocarbons) heat transfer loop of Kyushu University and supercritical water loop at JAEA. Heat transfer data including effect of grid spacers will be taken. The critical flow and condensation of supercritical fluid will be studied. The materials research includes the development and testing of austenitic stainless steel cladding from the experience of PNC1520 for LMFBR. Material for thermal insulation will be tested. SCWR (Supercritical-Water Cooled Reactor) of GIF (Generation-4 International Forum) includes both thermal and fast reactors. The research of the Super Fast Reactor will enhance SCWR research and the data base. The research period will be until March 2010. (authors)

Oka, Yoshiaki; Ishiwatari, Yuki; Liu, Jie; Terai, Takayuki; Nagasaki, Shinya; Muroya, Yusa; Abe, Hiroaki [Nuclear Professional School / Department of Nuclear Engineering and Management, The University of Tokyo, Tokaimura, Naka-gun, Ibaraki, 319-1188 (Japan); Mori, Hideo [Department of Mechanical Engineering, Kyushu University (Japan); Akiba, Masato; Akimoto, Hajime; Okumura, Keisuke; Akasaka, Naoaki [Japan Atomic Energy Agency (Japan); GOTO, Shoji [Tokyo Electric Power Company (Japan)

2006-07-01

490

Low power unattended defense reactor  

SciTech Connect

A small, low power, passive, nuclear reactor electric power supply has been designed for unattended defense applications. Through innovative utilization of existing proven technologies and components, a highly reliable, walk-away safe design has been obtained. Operating at a thermal power level of 200 kWt, the reactor uses low enrichment uranium fuel in a graphite block core to generate heat that is transferred through heat pipes to a thermoelectric (TE) converter. Waste heat is removed from the TEs by circulation of ambient air. Because such a power supply offers the promise of minimal operation and maintenance (O and M) costs as well as no fuel logistics, it is particularly attractive for remote, unattended applications such as the North Warning System.

Kirchner, W.L.; Meier, K.L.

1984-01-01

491

Modular Stellarator Fusion Reactor concept  

SciTech Connect

A preliminary conceptual study is made of the Modular Stellarator Reactor (MSR). A steady-state ignited, DT-fueled, magnetic fusion reactor is proposed for use as a central electric-power station. The MSR concept combines the physics of the classic stellarator confinement topology with an innovative, modular-coil design. Parametric tradeoff calculations are described, leading to the selection of an interim design point for a 4-GWt plant based on Alcator transport scaling and an average beta value of 0.04 in an l = 2 system with a plasma aspect ratio of 11. The physics basis of the design point is described together with supporting magnetics, coil-force, and stress computations. The approach and results presented herein will be modified in the course of ongoing work to form a firmer basis for a detailed conceptual design of the MSR.

Miller, R.L.; Krakowski, R.A.

1981-08-01

492

Requirements for Reactor Physics Design  

SciTech Connect

It has been recognized that there is a need for requirements and guidance for design and operation of nuclear power plants. This is becoming more important as more reactors are being proposed to be built. In parallel with activities in individual countries are norms established by international organizations. This paper discusses requirements/guidance for neutronic design and operation as promulgated by the U.S. Nuclear Regulatory Commission (NRC). As an example, details are given for one reactor physics parameter, namely, the moderator temperature reactivity coefficient. The requirements/guidance from the NRC are discussed in the context of those generated for the International Atomic Energy Agency. The requirements/guidance are not identical from the two sources although they are compatible.

Diamond,D.J.

2008-04-11

493

Integrated pool fusion reactor concept  

SciTech Connect

A new fusion reactor system concept has been developed based on a pool reactor configuration. The nuclear island, including only the first wall and the superconducting magnets, is submerged under a molten Flibe pool. The Flibe will fill the space between the first wall and the superconducting magnets and will provide the necessary magnet protection. Therefore, the Flibe serves multiple functions of breeding, cooling, moderating, and shielding thus eliminating the requirement for a structural blanket, reflector, and shield. The thickness requirement of the Flibe is approx. 120 cm for superconducting magnet protection, which is acceptable. Therefore, the only structural layer remaining between the plasma chamber and the toroidal field coil is the first wall.

Sze, D.K.

1986-01-01

494

(Meeting on fusion reactor materials)  

Microsoft Academic Search

During his visit to the KfK, Karlsruhe, F. W. Wiffen attended the IEA 12th Working Group Meeting on Fusion Reactor Materials. Plans were made for a low-activation materials workshop at Culham, UK, for April 1991, a data base workshop in Europe for June 1991, and a molecular dynamics workshop in the United States in 1991. At the 11th IEA Executive

R. H. Jones; R. L. Klueh; A. F. Rowcliffe; F. W. Wiffen; B. A. Loomis

1990-01-01