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in creator/contributor: "Piet, S."

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Uncertainties in modeling of consequences of tritium release from fusion reactors. Plasma Fusion Center No. PFC/TR-79-5

The bases for various models concerned with all phases of estimating doses from routine tritium releases from fusion reactors have been examined. The implications of uncertainties in parameters and assumptions for the uncertainty of the calculated doses and resulting maximum permissible releases are presented. Global dispersion models are most affected by the assumptions made concerning movement, such as the role of the ocean as a sink. Dose models were generally found to agree within a factor … more

Date: July 1, 1979

Creator: Piet, S.J. & Kazimi, M.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

ITER safety challenges and opportunities

Results of the Conceptual Design Activity (CDA) for the International Thermonuclear Experimental Reactor (ITER) suggest challenges and opportunities. ITER is capable of meeting anticipated regulatory dose limits,'' but proof is difficult because of large radioactive inventories needing stringent radioactivity confinement. We need much research and development (R D) and design analysis to establish that ITER meets regulatory requirements. We have a further opportunity to do more to prove more of… more

Date: January 1, 1991

Creator: Piet, S.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Exploratory study of burn time, duty factor, and fluence on ITER activation hazards

The safety analyses for the Conceptual Design Activity (CDA) of the International Thermonuclear Experimental Reactor (ITER) were based on the simplifying assumption that the activation of materials occurs continuously. Since the analyses showed a significant hazard, it is appropriate to examine how much hazard reduction might occur if this conservative assumption were relaxed. This report explores how much reduction might be gained by considering non-continuous operation, that is, by considerin… more

Date: August 1, 1992

Creator: Piet, S.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Impact of Nuclear Energy Futures on Advanced Fuel Cycle Options

The Nuclear Waste Policy Act requires the Secretary of Energy to inform Congress before 2010 on the need for a second geologic repository for spent nuclear fuel. By that time, the spent fuel discharged from current commercial reactors will exceed the statutory limit of the first repository. There are several approaches to eliminate the need for another repository in this century. This paper presents a high-level analysis of these spent fuel management options in the context of a full range of p… more

Date: October 3, 2004

Creator: Dixon, B. W. & Piet, S. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Assessment of problems associated with tritium containment

Preventing tritium leakage across a large heat transfer area at high temperature is one of the most difficult problems associated with a D-T fusion reactor design. One of the most efficient methods to reduce the mobility of tritium is to convert it to tritiated water. Most solid breeder systems use a purge gas and assume tritium will be oxidized into the water form. For 17 Li-83Pb system, a double-walled steam generator is used. Tritium is assumed to be oxidized across the gap in between the tw… more

Date: January 1, 1984

Creator: Sze, D.K.; Hassanein, A.; Piet, S.; Wong, C. & Bjorndahl, W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Engineering, safety, and economic evaluations of ASPIRE (Advanced Safe Pool Immersed REactor)

A preconceptual design of a tokamak fusion reactor concept called ASPIRE (Advanced Safe Pool Immersed REactor) has been developed. This concept provides many of the attractive features that are needed to enhance the capability of fusion to become the power generation technology for the 21st century. Specifically, these features are: inherent safety, low pressure, environmental compatibility, moderate unit size, high availability, high thermal efficiency, simplicity, low radioactive inventory, C… more

Date: February 1, 1988

Creator: Sze, D.K.; Gordon, J.; Piet, S.; Cheng, E.T. & Klein, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Conceptual design of a self-cooled Flibe blanket

A self-cooled Flibe blanket concept has been developed. The problems associated with tritium breeding, tritium containment, and corrosion have been investigated and potential solutions developed. A highly efficient and compact blanket and power conversion system has been incorporated. The resulting system is low pressure with high thermal efficiency and is inherently safe.

Date: June 1, 1986

Creator: Sze, D.K.; Jung, J.; Cheng, E.T.; Piet, S. & Klein, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Trends in fusion reactor safety research

Fusion has the potential to be an attractive energy source. From the safety and environmental perspective, fusion must avoid concerns about catastrophic accidents and unsolvable waste disposal. In addition, fusion must achieve an acceptable level of risk from operational accidents that result in public exposure and economic loss. Finally, fusion reactors must control routine radioactive effluent, particularly tritium. Major progress in achieving this potential rests on development of low-activa… more

Date: January 1, 1991

Creator: Herring, J. S.; Holland, D. F. & Piet, S. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Testing, Modeling, and Monitoring to Enable Simpler, Cheaper, Longer-lived Surface Caps

Society has and will continue to generate hazardous wastes whose risks must be managed. For exceptionally toxic, long-lived, and feared waste, the solution is deep burial, e.g., deep geological disposal at Yucca Mtn. For some waste, recycle or destruction/treatment is possible. The alternative for other wastes is storage at or near the ground level (in someone's back yard); most of these storage sites include a surface barrier (cap) to prevent downward water migration. Some of the hazards will … more

Date: February 25, 2003

Creator: Piet, S. J.; Breckenridge, R. P. & Burns, D. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Near-Surface Engineered Environmental Barrier Integrity

The INEEL Environmental Systems Research and Analysis (ESRA) program has launched a new R and D project on Near-Surface Engineered Environmental Barrier Integrity to increase knowledge and capabilities for using engineering and ecological components to improve the integrity of near-surface barriers used to confine contaminants from the public and the environment. The knowledge gained and the capabilities built will help verify the adequacy of past remedial decisions and enable improved solution… more

Date: May 15, 2002

Creator: Piet, S. J. & Breckenridge, R. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Overview of safety and environmental issues for inertial fusion energy

This paper summarizes safety and environmental issues of Inertial Fusion Energy (IFE): inventories, effluents, maintenance, accident safety, waste management, and recycling. The fusion confinement approach among inertial and magnetic options affects how the fusion reaction is maintained and which materials surround the reaction chamber. The target fill technology has a major impact on the target factory tritium inventory. IFE fusion reaction chambers usually employ some means to protect the fir… more

Date: December 31, 1996

Creator: Piet, S.J.; Brereton, S.J. & Tanaka, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Modeling and Simulation of Long-Term Performance of Near-Surface Barriers

Society has and will continue to generate hazardous wastes whose risks must be managed. For exceptionally toxic, long-lived, and feared waste, the solution is deep burial, e.g., deep geological disposal at Yucca Mtn. For some waste, recycle or destruction/treatment is possible. The alternative for other wastes is storage at or near the ground level (in someone's back yard); most of these storage sites include a surface barrier (cap) to prevent migration of the waste due to infiltration of surfa… more

Date: February 25, 2003

Creator: Piet, S. J.; Jacobson, J. J.; Martian, P.; Martineau, R. & Soto, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Computational Neutronics Methods and Transmutation Performance Analyses for Light Water Reactors

The urgency for addressing repository impacts has grown in the past few years as a result of Spent Nuclear Fuel (SNF) accumulation from commercial nuclear power plants. One obvious path that has been explored by many is to eliminate the transuranic (TRU) inventory from the SNF thus reducing the need for additional long term repository storage sites. One strategy for achieving this is to burn the separated TRU elements in the currently operating U.S. Light Water Reactor (LWR) fleet. Many studies… more

Date: March 1, 2007

Creator: Asgari, M.; Forget, B.; Piet, S.; Ferrer, R. & Bays, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Technology Insights and Perspectives for Nuclear Fuel Cycle Concepts

The following report provides a rich resource of information for exploring fuel cycle characteristics. The most noteworthy trends can be traced back to the utilization efficiency of natural uranium resources. By definition, complete uranium utilization occurs only when all of the natural uranium resource can be introduced into the nuclear reactor long enough for all of it to undergo fission. Achieving near complete uranium utilization requires technologies that can achieve full recycle or at le… more

Date: September 1, 2010

Creator: Bays, S.; Piet, S.; Soelberg, N.; Lineberry, M. & Dixon, B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Predictions of radioactive tungsten release for hypothetical ITER (International Thermonuclear Experimental Reactor) accidents

Postulated long-term loss of coolant accidents (LOCA) for the International Thermonuclear Experimental Reactor (ITER) may involve the ingress of air or steam into the plasma chamber. Reactions of these gases with the hot plasma facing components will cause oxidation, transport, and release of activated species. To predict radioactivity releases, we measured volatility rates from a tungsten alloy. Tests were performed in air or steam between 600 and 1200{degree}C for 1 to 20 h. We used these vol… more

Date: January 1, 1990

Creator: Smolik, G. R.; Piet, S. J. & Neilson, R. M., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Volatility from copper and tungsten alloys for fusion reactor applications

Accident scenarios for fusion power plants present the potential for release and transport of activated constituents volatilized from first wall and structural materials. The extent of possible mobilization and transport of these activated species, many of which are oxidation driven'', is being addressed by the Fusion Safety Program at the Idaho National Engineering Laboratory (INEL). This report presents experimental measurements of volatilization from a copper alloy in air and steam and from … more

Date: January 1, 1989

Creator: Smolik, G. R.; Neilson, R. M., Jr. & Piet, S. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Safety characteristics of options for plasma-facing components for ITER and beyond

Plasma-facing components (PFC) likely dominate the safety hazards of the International Thermonuclear Experimental Reactor (ITER) and post-ITER machines. To gain regulatory approval and for fusion energy to fulfill its ultimate attractive safety and environmental potential, safety must be considered when selecting among PFC options. This paper summarizes current PFC safety information. PFC safety issues fall into seven areas: disruption tolerance, disruption severity, tritium inventory and perme… more

Date: January 1, 1991

Creator: Piet, S. J.; McCarthy, K. A.; Holland, D. F.; Longhurst, G. R. & Merrill, B. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of graphite/steam interactions for ITER (International Thermonuclear Experimental Reactor)

In this report we present the results of an experimental/analytical study designed to determine the quantity of hydrogen generated during a coolant inleakage accident in ITER. This hydrogen could represent a potential explosive hazard, provided the proper conditions exist, causing machine damage and release of radioactive material. We have measured graphite/steam reaction rates for several graphites and carbon-based composites at temperatures between 1000 C and 1700 C. The effects of steam flow… more

Date: September 1, 1990

Creator: Smolik, G. R.; Merrill, B. J.; Piet, S. J. & Holland, D. F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Transmutation Dynamics: Impacts of Multi-Recycling on Fuel Cycle Performances

From a physics standpoint, it is feasible to sustain continuous multi-recycle in either thermal or fast reactors. In Fiscal Year 2009, transmutaton work at INL provided important new insight, caveats, and tools on multi-recycle. Multi-recycle of MOX, even with all the transuranics, is possible provided continuous enrichment of the uranium phase to ~6.5% and also limitting the transuranic enrichment to slightly less than 8%. Multi-recycle of heterogeneous-IMF assemblies is possible with continuo… more

Date: September 1, 2009

Creator: Bays, S.; Piet, S.; Pope, M.; Youinou, G.; Dumontier, A. & Hawn, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Answering Key Fuel Cycle Questions

Given the range of fuel cycle goals and criteria, and the wide range of fuel cycle options, how can the set of options eventually be narrowed in a transparent and justifiable fashion? It is impractical to develop all options. We suggest an approach that starts by considering a range of goals for the Advanced Fuel Cycle Initiative (AFCI) and then posits seven questions, such as whether Cs and Sr isotopes should be separated from spent fuel and, if so, what should be done with them. For each ques… more

Date: October 3, 2004

Creator: Piet, S. J.; Dixon, B. W.; Bennett, R. G.; Smith, J. D. & Hill, R. N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of graphite/steam interactions for ITER (International Thermonuclear Experimental Reactor) accident scenarios

This paper presents the results of an experimental/analytical study designed to determine the quantity of hydrogen generated during an accident involving coolant leakage into the plasma chamber of the International Thermonuclear Experimental Reactor (ITER). This hydrogen could represent a potential explosive hazard, provided the proper conditions exist, causing machine damage and release of radioactive material. We measured graphite/steam reaction rates for several graphites and carbon-based co… more

Date: January 1, 1990

Creator: Smolik, G. R.; Merrill, B. J.; Piet, S. J. & Holland, D. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Transmutation Performance Analysis for Inert Matrix Fuels in Light Water Reactors and Computational Neutronics Methods Capabilities at INL

The urgency for addressing repository impacts has grown in the past few years as a result of Spent Nuclear Fuel (SNF) accumulation from commercial nuclear power plants. One path that has been explored by many is to eliminate the transuranic (TRU) inventory from the SNF, thus reducing the need for additional long term repository storage sites. One strategy for achieving this is to burn the separated TRU elements in the currently operating U.S. Light Water Reactor (LWR) fleet. Many studies have e… more

Date: May 1, 2009

Creator: Pope, Michael A.; Bays, Samuel E.; Piet, S.; Ferrer, R.; Asgari, Mehdi & Forget, Benoit

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Modeling the Nuclear Fuel Cycle

The Advanced Fuel Cycle Initiative is developing a system dynamics model as part of their broad systems analysis of future nuclear energy in the United States. The model will be used to analyze and compare various proposed technology deployment scenarios. The model will also give a better understanding of the linkages between the various components of the nuclear fuel cycle that includes uranium resources, reactor number and mix, nuclear fuel type and waste management. Each of these components … more

Date: July 1, 2005

Creator: Jacobson, Jacob J.; Yacout, A. M.; Matthern, G. E.; Piet, S. J. & Moisseytsev, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

VISION -- A Dynamic Model of the Nuclear Fuel Cycle

The Advanced Fuel Cycle Initiative’s (AFCI) fundamental objective is to provide technology options that – if implemented – would enable long-term growth of nuclear power while improving sustainability and energy security. The AFCI organization structure consists of four areas; Systems Analysis, Fuels, Separations and Transmutations. The Systems Analysis Working Group is tasked with bridging the program technical areas and providing the models, tools, and analyses required to assess the feasibil… more

Date: February 1, 2006

Creator: Jacobson, J. J.; Yacout, A. M.; Piet, S. J.; Shropshire, D. E. & Matthern, G. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department