370 Matching Results

Search Results

Advanced search parameters have been applied.

Advanced reactors transition FY 1997 multi-year work plan WBS 7.3

Description: This document describes in detail the work to be accomplised in FY 1997 and the out-years for the Advanced Reactors Transition (WBS 7.3) under the management of the Babcock & Wilcox Hanford Company. This document also includes specific milestones and funding profiles. Based upon the Fiscal Year 1997 Multi-Year Work Plan, the Department of Energy will provide authorization to perform the work described.
Date: September 27, 1996
Creator: Hulvey, R.K.
Partner: UNT Libraries Government Documents Department

1998 FFTF annual system assessment reports

Description: The health of FFTF systems was assessed assuming a continued facility standby condition. The review was accomplished in accordance with the guidelines of FFTF-EI-083, Plant Evaluation Program. The attached document includes an executive summary of the significant conclusions and assessment reports for each system evaluated.
Date: March 19, 1998
Creator: Guttenberg, S.
Partner: UNT Libraries Government Documents Department

Planning for closure and deactivation of the EBR-II complex

Description: In January 1994, DOE terminated the Integral Fast Reactor (IFR) Program. Argonne National Laboratory-West (ANL-W) prepared a detailed plan to put Experimental Breeder Reactor-II (EBR-II) in a safe condition, including removal of irradiated fueled subassemblies from the plant, transfer of subassemblies, and removal and stabilization of primary and secondary sodium liquid heat transfer metal. The goal of deactivation is to stabilize the EBR-II complex until decontamination and decommissioning (D&D) is implemented, thereby minimizing maintenance and surveillance. Deactivation of a sodium cooled reactor presents unique concerns. Residual sodium in the primary and secondary systems must be either reacted or inerted to preclude concerns with explosive sodium-air reactions. Also, residual sodium on components will effectively solder these items in place, making removal unfeasible. Several special cases reside in the primary system, including primary cold traps, a cesium trap, a cover gas condenser, and systems containing sodium-potassium alloy. The sodium or sodium-potassium alloy in these components must be reacted in place or the components removed. The Sodium Components Maintenance Shop at ANL-W provides the capability for washing primary components, removing residual quantities of sodium while providing some decontamination capacity. Considerations need to be given to component removal necessary for providing access to primary tank internals for D&D activities, removal of hazardous materials, and removal of stored energy sources. ANL-W`s plan for the deactivation of EBR-II addresses these issues, providing for an industrially and radiologically safe complex, requiring minimal surveillance during the interim period between deactivation and D&D. Throughout the deactivation and closure of the EBR-II complex, federal environmental concerns will be addressed, including obtaining the proper permits for facility condition and waste processing and disposal. 2 figs.
Date: July 1, 1997
Creator: Michelbacher, J.A.; Henslee, S.P.; Poland, H.F. & Wells, P.B.
Partner: UNT Libraries Government Documents Department

Perspectives on Low Power and Shutdown Risk

Description: This paper presents results from a program sponsored by the US Nuclear Regulatory Commission to examine the risks from low power and shutdown operations. Significant progress has been made by the industry in reducing such risks; however, important operational events continue to occur. Current perceptions of low power and shutdown risks are discussed in the paper along with an assessment of the current methods for understanding important events and quantifying their associated risk.
Date: July 6, 2000
Partner: UNT Libraries Government Documents Department

A Fast Shutdown Technique for Large Tokamaks

Description: A practical method is proposed for the fast shutdown of a large ignited tokamak. The method consists of injecting a rapid series of 30-50 deuterium pellets doped with a small ( 0.0005%) concentration of Krypton impurity, and simultaneously ramping the plasma current and shaping fields down over a period of several seconds using the poloidal field system. Detailed modeling with the Tokamak Simulation Code using a newly developed pellet mass deposition model shows that this method should terminate the discharge in a controlled and stable way without producing significant numbers of runaway electrons. A partial prototyping of this technique was accomplished in TFTR.
Date: September 1, 1999
Creator: Fredrickson, E.; Schmidt, G.L.; Hill, K.; Jardin, S.C. & al, et
Partner: UNT Libraries Government Documents Department

Research reactor de-fueling and fuel shipment

Description: Planning for the Georgia Institute of Technology Research Reactor operations during the 1996 Summer Olympic Games began in early 1995. Before any details could be outlined, several preliminary administrative decisions had to be agreed upon by state, city, and university officials. The two major administrative decisions involving the reactor were (1) the security level and requirements and (2) the fuel status of the reactor. The Georgia Tech Research Reactor (GTRR) was a heavy-water moderated and cooled reactor, fueled with high-enriched uranium. The reactor was first licensed in 1964 with an engineered lifetime of thirty years. The reactor was intended for use in research applications and as a teaching facility for nuclear engineering students and reactor operators. Approximately one year prior to the olympics, the Georgia Tech administration decided that the GTRR fuel would be removed. In addition, a heightened, beyond regulatory requirements, security system was to be implemented. This report describes the scheduling, operations, and procedures.
Date: August 1, 1998
Creator: Ice, R.D.; Jawdeh, E. & Strydom, J.
Partner: UNT Libraries Government Documents Department

Impact induced response spectrum for the safety evaluation of the high flux isotope reactor

Description: The dynamic impact to the nearby HFIR reactor vessel caused by heavy load drop is analyzed. The impact calculation is carried out by applying the ABAQUS computer code. An impact-induced response spectrum is constructed in order to evaluate whether the HFIR vessel and the shutdown mechanism may be disabled. For the frequency range less than 10 Hz, the maximum spectral velocity of impact is approximately equal to that of the HFIR seismic design-basis spectrum. For the frequency range greater than 10 Hz, the impact-induced response spectrum is shown to cause no effect to the control rod and the shutdown mechanism. An earlier seismic safety assessment for the HFIR control and shutdown mechanism was made by EQE. Based on EQE modal solution that is combined with the impact-induced spectrum, it is concluded that the impact will not cause any damage to the shutdown mechanism, even while the reactor is in operation. The present method suggests a general approach for evaluating the impact induced damage to the reactor by applying the existing finite element modal solution that has been carried out for the seismic evaluation of the reactor.
Date: May 1, 1997
Creator: Chang, S.J.
Partner: UNT Libraries Government Documents Department

US graphite reactor D&D experience

Description: This report describes the results of the U.S. Graphite Reactor Experience Task for the Decommissioning Strategy Plan for the Leningrad Nuclear Power Plant (NPP) Unit 1 Study. The work described in this report was performed by the Pacific Northwest National Laboratory (PNNL) for the Department of Energy (DOE).
Date: February 1, 1997
Creator: Garrett, S.M.K. & Williams, N.C.
Partner: UNT Libraries Government Documents Department

Advanced Test Reactor outage risk assessment

Description: Beginning in 1997, risk assessment was performed for each Advanced Test Reactor (ATR) outage aiding the coordination of plant configuration and work activities (maintenance, construction projects, etc.) to minimize the risk of reactor fuel damage and to improve defense-in-depth. The risk assessment activities move beyond simply meeting Technical Safety Requirements to increase the awareness of risk sensitive configurations, to focus increased attention on the higher risk activities, and to seek cost-effective design or operational changes that reduce risk. A detailed probabilistic risk assessment (PRA) had been performed to assess the risk of fuel damage during shutdown operations including heavy load handling. This resulted in several design changes to improve safety; however, evaluation of individual outages had not been performed previously and many risk insights were not being utilized in outage planning. The shutdown PRA provided the necessary framework for assessing relative and absolute risk levels and assessing defense-in-depth. Guidelines were written identifying combinations of equipment outages to avoid. Screening criteria were developed for the selection of work activities to receive review. Tabulation of inherent and work-related initiating events and their relative risk level versus plant mode has aided identification of the risk level the scheduled work involves. Preoutage reviews are conducted and post-outage risk assessment is documented to summarize the positive and negative aspects of the outage with regard to risk. The risk for the outage is compared to the risk level that would result from optimal scheduling of the work to be performed and to baseline or average past performance.
Date: December 31, 1997
Creator: Thatcher, T.A. & Atkinson, S.A.
Partner: UNT Libraries Government Documents Department

Natural Convection and Boiling for Cooling SRP Reactors During Loss of Circulation Conditions

Description: This study investigated natural convection and boiling as a means of cooling SRP reactors in the event of a loss of circulation accident. These studies show that single phase natural convection cooling of SRP reactors in shutdown conditions with the present piping geometry is probably not feasible.
Date: June 26, 2001
Creator: Buckner, M.R.
Partner: UNT Libraries Government Documents Department

Production test IP-728 half-plant sodium silicate test. Final report

Description: The sodium silicate addition to the coolant reduced the effluent concentrations of certain radionuclides. Nothing was observed during the course of the test to indicate that sodium silicate could not be used at all plants. However, the reductions obtained in effluent activity are not believed commensurate with the cost of silicate usage.
Date: July 28, 1966
Creator: Geier, R.G.
Partner: UNT Libraries Government Documents Department

Evaluation of potential severe accidents during low power and shutdown operations at Surry: Unit 1, Volume 1

Description: This document contains a summarization of the results and insights from the Level 1 accident sequence analyses of internally initiated events, internally initiated fire and flood events, seismically initiated events, and the Level 2/3 risk analysis of internally initiated events (excluding fire and flood) for Surry, Unit 1. The analysis was confined to mid-loop operation, which can occur during three plant operational states (identified as POSs R6 and R10 during a refueling outage, and POS D6 during drained maintenance). The report summarizes the Level 1 information contained in Volumes 2--5 and the Level 2/3 information contained in Volume 6 of NUREG/CR-6144.
Date: October 1995
Creator: Chu, T. L.; Pratt, W. T. & Musicki, Z.
Partner: UNT Libraries Government Documents Department

Replacement energy, capacity, and reliability costs for permanent nuclear reactor shutdowns

Description: Average replacement power costs are estimated for potential permanent shutdowns of nuclear electricity-generating units. Replacement power costs are considered to include replacement energy, capacity, and reliability cost components. These estimates were developed to assist the US Nuclear Regulatory Commission in evaluating regulatory issues that potentially affect changes in serious reactor accident frequencies. Cost estimates were derived from long-term production-cost and capacity expansion simulations of pooled utility-system operations. Factors that affect replacement power cost, such as load growth, replacement sources of generation, and capital costs for replacement capacity, were treated in the analysis. Costs are presented for a representative reactor and for selected subcategories of reactors, based on estimates for 112 individual reactors.
Date: October 1, 1993
Creator: VanKuiken, J. C., Buehring, W. A.; Hamilton, S.; Kavicky, J. A.; Cavallo, J. D.; Veselka, T. D. & Willing, D. L.
Partner: UNT Libraries Government Documents Department

International Collaboration with the Shutdown of the BN-350 Reactor

Description: Representatives from the United States and the United Kingdom discussed areas where collaboration on the shutdown of the BN-350 Reactor in Aktau, Kazakhstan would benefit not only Kazakhstan, but would also help to assure the successful shutdown of the reactor. A fundamental understanding of the basis for collaboration has been for each side to ‘add value’ to each of the project areas, rather than simply substitute for each other’s experience. This approach has brought distinct technical and management benefits to the decommissioning activities in Kazakhstan.
Date: August 1, 2005
Creator: Michelbacher, J. A.; Wells, P. B.; Organ, N. & Wells, D.
Partner: UNT Libraries Government Documents Department


Description: The AGR-1 experiment is a multiple fueled-capsule irradiation experiment being conducted in the Advanced Test Reactor (ATR) in support of the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. The experiment began irradiation in the ATR with a cycle that reached full power on December 26, 2006 and ended with shutdown of the reactor for a brief outage on February 10, 2007 at 0900. The AGR-1 experiment will continue cyclical irradiation for about 2.5 years. In order to allow estimation of the amount of radioiodine released during the first cycle, purge gas flow to all capsules continued for about 4 days after reactor shutdown. The FPMS data acquired during part of that shutdown flow period has been analyzed to elucidate the level of 135I released during the operating cycle.
Date: May 1, 2007
Creator: Hartwell, J. K.; Scates, D. M.; Walter, J. B. & Drigert, M. W.
Partner: UNT Libraries Government Documents Department

Monitoring the Thermal Power of Nuclear Reactors with a Prototype Cubic Meter Antineutrino Detector

Description: In this paper, we estimate how quickly and how precisely a reactor's operational status and thermal power can be monitored over hour to month time scales, using the antineutrino rate as measured by a cubic meter scale detector. Our results are obtained from a detector we have deployed and operated at 25 meter standoff from a reactor core. This prototype can detect a prompt reactor shutdown within five hours, and monitor relative thermal power to 3.5% within 7 days. Monitoring of short-term power changes in this way may be useful in the context of International Atomic Energy Agency's (IAEA) Reactor Safeguards Regime, or other cooperative monitoring regimes.
Date: June 27, 2007
Creator: Bernstein, A; Bowden, N; Misner, A & Palmer, T
Partner: UNT Libraries Government Documents Department

A level control model for BWR emergency procedure guidelines

Description: The level control during an Anticipated Transient Without Scram (ATWS) event in a BWR as prescribed in the Emergency Procedure Guidelines (EPG) is a difficult task for the operator for he has to keep the water level at the top of active fuel (TAF) without uncovering the reactor core. Also the computer simulation of EPG level control will require many trial and error calculations with the Emergency Core Cooling System (ECCS). A level control system model has been developed and implemented in the RAMONA-4B code in order to simulate the EPG level control without iterations. The model has been extensively tested and the results demonstrate that the model can simulate the EPG level control strategy. The calculations also show that the level control system will speed up the boron circulation to shut down the reactor sooner than the manual control. Furthermore, the suppression pool temperature is predicted to remain within the Technical Specification limit during a MSIV closure ATWS with the proposed level control strategy. 3 refs., 11 figs., 1 tab.
Date: October 1, 1996
Creator: Cheng, H.S. & Rohatgi, U.S.
Partner: UNT Libraries Government Documents Department

Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Evaluation of severe accident risks for plant operational state 5 during a refueling outage. Supporting MELCOR calculations, Volume 6, Part 2

Description: To gain a better understanding of the risk significance of low power and shutdown modes of operation, the Office of Nuclear Regulatory Research at the NRC established programs to investigate the likelihood and severity of postulated accidents that could occur during low power and shutdown (LP&S) modes of operation at commercial nuclear power plants. To investigate the likelihood of severe core damage accidents during off power conditions, probabilistic risk assessments (PRAs) were performed for two nuclear plants: Unit 1 of the Grand Gulf Nuclear Station, which is a BWR-6 Mark III boiling water reactor (BWR), and Unit 1 of the Surry Power Station, which is a three-loop, subatmospheric, pressurized water reactor (PWR). The analysis of the BWR was conducted at Sandia National Laboratories while the analysis of the PWR was performed at Brookhaven National Laboratory. This multi-volume report presents and discusses the results of the BWR analysis. The subject of this part presents the deterministic code calculations, performed with the MELCOR code, that were used to support the development and quantification of the PRA models. The background for the work documented in this report is summarized, including how deterministic codes are used in PRAS, why the MELCOR code is used, what the capabilities and features of MELCOR are, and how the code has been used by others in the past. Brief descriptions of the Grand Gulf plant and its configuration during LP&S operation and of the MELCOR input model developed for the Grand Gulf plant in its LP&S configuration are given.
Date: March 1, 1995
Creator: Kmetyk, L.N. & Brown, T.D.
Partner: UNT Libraries Government Documents Department

PSA-operations synergism for the advanced test reactor shutdown operations PSA

Description: The Advanced Test Reactor (ATR) Probabilistic Safety Assessment (PSA) for shutdown operations, cask handling, and canal draining is a successful example of the importance of good PSA-operations synergism for achieving a realistic and accepted assessment of the risks and for achieving desired risk reduction and safety improvement in a best and cost-effective manner. The implementation of the agreed-upon upgrades and improvements resulted in the reductions of the estimated mean frequency for core or canal irradiated fuel uncovery events, a total reduction in risk by a factor of nearly 1000 to a very low and acceptable risk level for potentially severe events.
Date: August 1, 1996
Creator: Atkinson, S.A.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: June 1, 1995
Partner: UNT Libraries Government Documents Department