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DOE OSTI2016

Status of the RF-driven H{sup −} ion source for J-PARC linac

For the upgrade of the Japan Proton Accelerator Research Complex linac beam current, a cesiated RF-driven negative hydrogen ion source was installed during the 2014 summer shutdown period, with subsequent operations commencing on September 29, 2014. The ion source has been successfully operating with a beam current and duty factor of 33 mA and 1.25% (500 μs and 25 Hz), respectively. The result of recent beam operation has demonstrated that the ion source is capable of continuous operation for approximately 1100 h. The spark rate at the beam extractor was observed to be at a frequency of less than once a day, which is an acceptable level for user operation. Although an antenna failure occurred during operation on October 26, 2014, no subsequent serious issues have occurred since then.

43 PARTICLE ACCELERATORS↗

DOE OSTI2016

Refurbishment of radiation-damaged undulators

Partial radiation damage has been observed over the previous five years of operation for a few of the PETRA III permanent magnet undulators at DESY. The degradation of the affected devices has been observed by a change in the energy tuning curves and the spectral properties of the undulator harmonics, and also by direct measurements of the peak field distribution of the magnet structure in the storage ring tunnel [1]. During the recent shutdown of the machine, two undulators were removed from the tunnel for repair. One of the devices (U29) has been retuned after flipping of all magnets of the hybrid structure. In addition to this temporary repair, one further magnet structure (U23) has been completely disassembled and refurbished by application of a rare earth diffusion process and a coating to the permanent magnets. We will report on the details of the refurbishment of these undulators which were both fully brought back to specifications and are meanwhile back in operation.

43 PARTICLE ACCELERATORS↗

DOE OSTI2019

Assessment of Activation on Level L3 of the Tokamak Building due to the ITER Tokamak Cooling Water System

The ITER fusion reactor is being built to demonstrate the feasibility of fusion power and will be the largest tokamak in the world. The tokamak cooling water system (TCWS) will extract the heat generated during operations and includes large amounts of piping and equipment such as pumps and heat exchangers (HXs) that are located in a large shielded region on level L3 of the tokamak building. During operation, water in the TCWS will be activated by plasma neutrons and then flow into this shielded region. The activated coolant will in turn activate the steel in the TCWS during operation and result in an activation gamma source and radiation responses that must be assessed to inform equipment selection and maintenance schedules.The activation of materials in the shielded region of level L3 was assessed at several decay times and for different equipment options using the Oak Ridge National Laboratory (ORNL) shutdown dose rate (SDDR) code suite. The ORNL SDDR code suite implements the rigorous two-step method using the Multi-Step Consistent Adjoint-Driven Importance Sampling (MS-CADIS) method to create effective neutron variance reduction parameters for the photon response of interest. In conclusion, two different HX designs, shell and tube and shell and plate, were considered, as well as the impact of cobalt impurities in steel equipment.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2013

The regulatory framework for safe decommissioning of nuclear power plants in Korea

We are having 23 units of nuclear power plants in operation and 5 units of nuclear power plants under construction in Korea as of September 2012. However, we don't have any experience on shutdown permanently and decommissioning of nuclear power plants. There are only two research reactors being decommissioned since 1997. It is realized that improvement of the regulatory framework for decommissioning of nuclear facilities has been emphasized constantly from the point of view of IAEA's safety standards. It is also known that IAEA will prepare the safety requirement on decommissioning of facilities; its title is the Safe Decommissioning of Facilities, General Safety Requirement Part 6. According to the result of IAEA's Integrated Regulatory Review Service (IRRS) mission to Korea in 2011, it was recommended that the regulatory framework should require decommissioning plans for nuclear installations to be constructed and operated and these plans should be updated periodically. In addition, after the Fukushima nuclear disaster in Japan in March of 2011, preparedness for early decommissioning caused by an unexpected severe accident became important issues and concerns. In this respect, it is acknowledged that the regulatory framework for decommissioning of nuclear facilities in Korea need to be improved. First of all, we focus on identifying the current status and relevant issues of regulatory framework for decommissioning of nuclear power plants compared to the IAEA's safety standards in order to achieve our goal. And then the plan is established for improvement of regulatory framework for decommissioning of nuclear power plants in Korea. It is expected that if the things will go forward as planned, the revised regulatory framework for decommissioning could enhance the safety regime on the decommissioning of nuclear power plants in Korea in light of international standards. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2013

Belgian regulatory framework for decontamination and decommissioning - lessons learned and new initiatives

Belgium can rely on significant experience in the field of decontamination and decommissioning of nuclear facilities. Several projects are ongoing and include research reactors (BR3, Thetis), uranium and MOX fuel fabrication plants (FBFC International, Belgonucleaire), fuel reprocessing facilities (Eurochemic) and radwaste processing facilities (Belgoprocess). Additional projects are expected in the coming years with the planned final shutdown of the oldest nuclear power reactor units. Two national authorities are involved in the decontamination and decommissioning process of nuclear facilities. The FANC (together with its subsidiary Bel V) is concerned for all matters related to nuclear safety and radiation protection, while NIRAS/ONDRAF is concerned for all matters related to radioactive waste and fuel management and financial provisions. These attributions ensure that all safety and material concerns are addressed and that both the licensees and the national authorities bear their own responsibilities. They rely on an existing regulatory framework covering both the procedural and the technical aspects of the decontamination and decommissioning activities. However, opportunities for regulatory improvement were raised after some recent events in Belgium, among which the bankruptcy of a nuclear company producing radioisotopes, involving numerous additional interested parties in a complex judiciary context. Amendments in the current regulations are considered to increase the prerogatives of the authorities regarding the management of radioactive waste by a licensee, the transfer of an operating license from an operator to another, and the general decommissioning strategy of a facility. Furthermore, a dedicated 'waste and decommissioning' working group within WENRA defined new reference levels applying to the decontamination and decommissioning of nuclear facilities. Belgium committed to include these requirements explicitly in its national legislation, even though most of them were already included in the existing decommissioning authorizations. Amendments will cover the safety provisions inherent to the decontamination and decommissioning phase, such as the decommissioning strategy, the qualification of techniques, the experience feedback valorization, the periodic safety reviews, the radioactive waste management, or the final characterization of the sites. Additionally, requirements regarding the authorization process will be detailed, such as the content of the licensee's application file or the structure of the safety report covering the decontamination and decommissioning phase. These changes will contribute to a more secure regulatory framework for all interested parties. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2013

DASAO: software tool for the management of safeguards, waste and decommissioning

Decommissioning of nuclear facilities is a complex process involving operations such as detailed surveys, decontamination and dismantling of equipment's, demolition of buildings and management of resulting waste and nuclear materials if any. This process takes place in a well-developed legal framework and is controlled and followed-up by stakeholders like the Safety Authority, the Radwaste management Agency and the Safeguards Organism. In the framework of its nuclear waste and decommissioning program and more specifically the decommissioning of the BR3 reactor, SCK-CEN has developed different software tools to secure the waste and material traceability, to support the sound management of the decommissioning project and to facilitate the control and the follow-up by the stakeholders. In the case of Belgium, it concerns the Federal Agency for Nuclear Control, the National Agency for radioactive waste management and fissile material and EURATOM and IAEA. In 2005, Belgonucleaire decided to shutdown her Dessel MOX fuel fabrication plant and the production stopped in 2006. According to the final decommissioning plan ('PDF') approved by NIRAS, the decommissioning works should start in 2008 at the earliest. In 2006, the management of Belgonucleaire identified the need for an integrated database and decided to entrust SCK-CEN with its development, because SCK-CEN relies on previous experience in comparable applications namely already approved by authorities such as NIRAS, FANC and EURATOM. The main objectives of this integrated software tool are: - simplified and updated safeguards; - waste and material traceability; - computerized documentation; - support to project management; - periodic and final reporting to waste and safety authorities. The software called DASAO (Database for Safeguards, Waste and Decommissioning) was successfully commissioned in 2008 and extensively used from 2009 to the satisfaction of Belgonucleaire and the stakeholders. SCK-CEN is now implementing a simplified release of the software for the management of the decommissioning of the Thetis reactor. Its decommissioning will start in March 2013 and will be completed by the end of 2014. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2017

Special features of the inverse-beta-decay reaction proceeding on a proton in a reactor-antineutrino flux

The evolution of the reactor-antineutrino spectrum and the evolution of the spectrum of positrons from the inverse-beta-decay reaction in the course of reactor operation and after reactor shutdown are considered. The present-day status in determining the initial reactor-antineutrino spectrum on the basis of spectra of beta particles from mixtures of products originating from uranium and plutonium fission is described. A local rise of the experimental spectrum of reactor antineutrinos with respect to the expected spectrum is studied.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2017

Upgrade of hadron endcap calorimeters CMS at LHC

We present the survey of the main tasks in upgrading the hadron endcap (HE) calorimeters of the CMS experiment at LHC. The results of the HE upgrade during the LHC Long Shutdown (2013–2014) and plans for upgrade during LHC Extended Year End Technical Stop (December 2016–May 2017) are discussed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2014

Evaluation of Neutron Radiography Reactor LEU-Core Start-Up Measurements

Benchmark models were developed to evaluate the cold-critical start-up measurements performed during the fresh core reload of the Neutron Radiography (NRAD) reactor with Low Enriched Uranium (LEU) fuel. Experiments include criticality, control-rod worth measurements, shutdown margin, and excess reactivity for four core loadings with 56, 60, 62, and 64 fuel elements. The worth of four graphite reflector block assemblies and an empty dry tube used for experiment irradiations were also measured and evaluated for the 60-fuel-element core configuration. Dominant uncertainties in the experimental k eff come from uncertainties in the manganese content and impurities in the stainless steel fuel cladding as well as the 236 U and erbium poison content in the fuel matrix. Calculations with MCNP5 and ENDF/B-VII.0 neutron nuclear data are approximately 1.4% (9σ) greater than the benchmark model eigenvalues, which is commonly seen in Monte Carlo simulations of other TRIGA reactors. Simulations of the worth measurements are within the 2σ uncertainty for most of the benchmark experiment worth values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2012

SCALE Code Validation for Prismatic High-Temperature Gas-Cooled Reactors

Using experimental data published in the International Handbook of Evaluated Reactor Physics Benchmark Experiments for the fresh cold core of the High Temperature Engineering Test Reactor, a comprehensive validation study has been carried out to assess the performance of the SCALE code system for analysis of High Temperature Gas-Cooled Reactor (HTGR) configurations. This paper describes part of the results of this effort. The studies performed included criticality evaluations for the full core and for the annular cores realized during the fuel loading, as well as calculations and comparisons for excess reactivity, shutdown margin, control rod worths, temperature coefficient of reactivity, and reaction rate distributions. Comparisons of the SCALE results with both the experimental values and MCNP-calculated values are presented. The comparisons show that the SCALE calculated results, obtained with both multigroup and continuous energy cross sections, are in reasonable agreement with the experimental data. The agreement with the MCNP predictions is, in general, very good.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI1993

Nuclear Safety [Vol. 34, No. 1, January-March 1993]

Nuclear Safety is a review journal that covers significant developments in the field of nuclear safety. Its scope includes the analysis and control of hazards associated with nuclear energy, operations involving fissionable materials, and the products of nuclear fission and their effects on the environment. Primary emphasis is on safety in reactor design, construction, and operation; however, the safety aspects of the entire fuel cycle, including fuel fabrication, spent-fuel processing, nuclear waste disposal, handling of radioisotopes, and environmental effects of these operations, are also treated. Table of Contents for this issue follows. GENERAL SAFETY CONSIDERATIONS: 1 An Integrated Regional Approach To Risk Management of Industrial Systems, S. Chakraborty and R. Stratton; 9 Annual Technical Meeting of the NRC Cooperative Severe Accident Research Program, E. G. Silver; ACCIDENT ANALYSIS: 13 Deterministic Severe Accident Criteria as Severe Accident Design Criteria and Policy for the New Production Reactor-Heavy Water Reactor, P. T. Rhoads; 20 Proposed Deterministic Severe Accident Criteria for the Heavy Water Reactor-New Production Reactor Containment, K. D. Bergeron, S. E. Slezak, and C. E. Leach; 33 Quasi-Static Core Liquid Level Depression and Long-Term Core Uncovery During a PWR LOCA, Y. Kukita, R. R. Schultz, H. Nakamura, and J. Katayama; 49 LIRA: An Advanced Containment System to Minimize the Accidental Radioactivity Releases, A. Turricchia; 63 Errata to “A Review of Hydrogen Production During Melt/Water Interaction in LWRs,” Vol. 33, No. 4; CONTROL AND INSTRUMENTATION: 64 The Nuplex 80+™ Advanced Control Complex from ABB Combustion Engineering, F. Ridolfo, D. Harmon, and K. Scarola; DESIGN FEATURES: 76 A Scheme for Passive Isolation of the Containment of a Reactor, A. K. Ghosh, V. V. Raj, and K. Kakodkar; 84 Utility Requirements for Safety in the Passive Advanced Light-Water Reactor, T. U. Marston, W. H. Layman, and G. Bockhold, Jr.; WASTE AND SPENT FUEL MANAGEMENT: 91 Activities Related to Waste and Spent Fuel Management, Compiled by M. D. Muhlheim and E. G. Silver; OPERATING EXPERIENCES: 103 Testing Deficiencies in Auxiliary Systems Feedwater Systems, J. D. Kueck; 110 Reactor Shutdown Experience, Compiled by J. W. Cletcher; 113 Selected Safety-Related Events, Compiled by G. A. Murphy; 115 Operating U.S. Power Reactors, Compiled by M. D. Muhlheim and E. G. Silver; RECENT DEVELOPMENTS: 133 General Administrative Activities, Compiled by M. D. Muhlheim and E. G. Silver; 145 Reports, Standards, and Safety Guides, D. S. Queener; 150 Proposed Rule Changes as of Sept. 30, 1992; ANNOUNCEMENTS: 75 Harvard Short Course on Risk: Science, Assessment, and Management; 102 International Conference on Reactor Physics and Reactor Computations; 102 The Fourth International Conference on Nuclear Waste Reprocessing and Waste Management [RECOD ’94]; 132 International Symposium on the Radiological Exposure of the Population of the European Community from Radioactivity in the Mediterranean Sea [MARINA-MED]; 162 International High-Level Radioactive Waste Conference ‘Technology Integration—Above and Below”; 154 The Authors; 158 Indexes to Nuclear Safety, Volume 33.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2012

Technical Assistance to Developers

This task supports the allowance of technical assistance to fuel-cell component and system developers as directed by the DOE. This task includes testing of novel materials and participation in the further development and validation of single cell test protocols. This task also covers technical assistance to DOE Working Groups, the U.S. Council for Automotive Research (USCAR) and the USCAR/DOE Driving Research and Innovation for Vehicle efficiency and Energy sustainability (U.S. Drive) Fuel Cell Technology Team. Assistance includes technical validation of new fuel cell materials and methods, single cell fuel cell testing to support the development of targets and test protocols, and regular advisory participation in other working groups and reviews. This assistance is made available to PEM fuel cell developers by request and DOE Approval. The objectives are to: (1) Support technically, as directed by DOE, fuel cell component and system developers; (2) Assess fuel cell materials and components and give feedback to developers; (3) Assist the DOE Durability Working Group with the development of various new material durability Testing protocols; and (4) Provide support to the U.S. Council for Automotive Research (USCAR) and the USCAR/DOE Fuel Cell Technology Team. FY2012 specific technical objectives are: (1) Evaluate novel MPL materials; (2) Develop of startup/ shutdown protocol; (3) Test the impact of hydrophobic treatment on graphite bi-polar plates; (4) Perform complete diagnostics on metal bi-polar plates for corrosion; and (5) Participate and lead efforts in the DOE Working Groups.

08 HYDROGEN↗

DOE OSTI2012

Ground Vibration Measurements at LHC Point 4

Ground vibration was measured at Large Hadron Collider (LHC) Point 4 during the winter shutdown in February 2012. This report contains the results, including power and coherence spectra. We plan to collect and analyze vibration data from representative collider halls to inform specifications for future linear colliders, such as ILC and CLIC. We are especially interested in vibration correlations between final focus lens locations.

43 PARTICLE ACCELERATORS↗

DOE OSTI2016

Analysis of Loss-of-Offsite-Power Events 1997-2015

Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. LOOP event frequencies and times required for subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience during calendar years 1997 through 2015. LOOP events during critical operation that do not result in a reactor trip, are not included. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. Emergency diesel generator reliability is also considered (failure to start, failure to load and run, and failure to run more than 1 hour). There is an adverse trend in LOOP durations. The previously reported adverse trend in LOOP frequency was not statistically significant for 2006-2015. Grid-related LOOPs happen predominantly in the summer. Switchyard-centered LOOPs happen predominantly in winter and spring. Plant-centered and weather-related LOOPs do not show statistically significant seasonality. The engineering analysis of LOOP data shows that human errors have been much less frequent since 1997 than in the 1986 -1996 time period.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI1995

Nuclear Safety [Vol. 36, No. 2, July-December 1995]

Nuclear Safety is a journal that covers significant issues in the field of nuclear safety. Its primary scope is safety in the design, construction, operation, and decommissioning of nuclear power reactors worldwide and the research and analysis activities that promote this goal, but it also encompasses the safety aspects of the entire nuclear fuel cycle, including fuel fabrication, spent-fuel processing and handling, and nuclear waste disposal, the handling of fissionable materials and radioisotopes, and the environmental effects of all these activities. Table of Contents for this issue follows. THE CHORNOBYL ACCIDENT: 195 The Chornobyl Accident Revisited, Part III: Chernobyl Source Term Release Dynamics and Reconstruction of Events During the Active Phase, A. R. Sich; GENERAL SAFETY CONSIDERATIONS: 218 Second ANS Workshop on the Safety of Soviet-Designed Nuclear Power Plants, R. A. Bari; 234 Elements of a Nuclear Criticality Safety Program, C. M. Hopper; 243 Rickover, Excellence, and Criticality Safety Programs, R. E. Wilson; ACCIDENT ANALYSIS: 249 Transient Analysis of the PIUS Advanced Reactor Design with the TRAC-PF1/MOD2 Code, B. E. Boyack, J. L Steiner, S. C. Harmony, H. J. Stumpf, and J. F. Lime; 278 The Hierarchy-By-Interval Approach to Identifying Important Models that Need Improvement in Severe-Accident Simulation Codes, T. J. Heames, M. Khatib-Rahbar, J. E. Kelly, R. P. Jenks-Johnson, and Y.-S. Chen; 290 RELAP5/MOD3 Code Coupling Model, R. P. Martin; 299 Missiles Caused by Severe Pressurized-Water Reactor Accidents, R. Krieg; DESIGN FEATURES: 310 Validation of COMMIX with Westinghouse AP-600 PCCS Test Data, J. G. Sun, T. H. Chien, J. Ding, and W T. Sha; ENVIRONMENTAL EFFECTS: 321 Spent Nuclear Fuel Characterization for a Bounding Reference Assembly for the Receiving Basin for Off-Site Fuel, S. D. Kahook, R. L. Garrett, L. R. Canas, and M J. Beckum; OPERATING EXPERIENCES: 332 Reactor Shutdown Experience, Compiled by J. W. Cletcher; U.S. NUCLEAR REGULATORY COMMISSION INFORMATION AND ANALYSES: 335 Reactor Coolant System Blowdown at Wolf Creek on September 17, 1994, J. V. Kauffman and S. L. Israel; RECENT DEVELOPMENTS: 344 Reports, Standards, and Safety Guides, D. S. Oueener; 349 Proposed Rule Changes as of June 30, 1995; ANNOUNCEMENTS: 320 Symposium on Acceptability of Risk From Radiation—Application to Manned Space Flight; 320 24th DOE/NRC Nuclear Air Cleaning and Treatment Conference; 361 Radiation Biology and Radiation Protection— Modern Developments and Tendencies in Radiation Biology; 362 1997 IEEE Sixth Conference on Human Factors and Power Plants; 354 The Authors; 360 Reviewers of Nuclear Safety, Vol. 36.

05 NUCLEAR FUELS↗

DOE OSTI2026

A Streamlined, Open Source Neutronics Toolkit for Fusion Reactor Design (Final Report)

Final report for the DOE Fusion Energy Sciences project titled "A Streamlined, Open Source Neutronics Toolkit for Fusion Reactor Design". This project developed unstructured mesh tracking capabilities in OpenMC as well as two shutdown dose rate methodologies, and performed extensive performance improvements and validation of the open source Monte Carlo code, OpenMC.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI1996

Nuclear Safety [Vol. 37, No. 3, July-September 1996]

05 NUCLEAR FUELS↗

DOE OSTI2012

Target Strength of Southern Resident Killer Whales (Orcinus orca): Measurement and Modeling

A major criterion for tidal power licensing in Washington’s Puget Sound is the management of the risk of injury to killer whales due to collision with moving turbine blades. An active monitoring system is being proposed for killer whale detection, tracking, and alerting that links to and triggers temporary turbine shutdown when there is risk of collision. Target strength (TS) modeling of the killer whale is critical to the design and application of any active monitoring system. A 1996 study performed a high-resolution measurement of acoustic reflectivity as a function of frequency of a female bottlenose dolphin (2.2 m length) at broadside aspect and TS as a function of incident angle at 67 kHz frequency. Assuming that killer whales share similar morphology structure with the bottlenose dolphin, we extrapolated the TS of an adult killer whale 7.5 m in length at 67 kHz frequency with -8 dB at broadside aspect and -28 dB at tail side. The backscattering data from three Southern Resident killer whales were analyzed to obtain the TS measurement. These data were collected at Lime Kiln State Park using a split-beam system deployed from a boat. The TS of the killer whale at higher frequency (200 kHz) was estimated based on a three-layer model for plane wave reflection from the lung of the whale. The TS data of killer whales were in good agreement with our model. In this paper, we also discuss and explain possible causes for measurement estimation error.

16 TIDAL AND WAVE POWER↗