Project PISA: Phosphorus Influence on Steel Ageing

The integrity of the pressure vessel is vital to the safe operation of a nuclear reactor. It is therefore necessary to monitor or predict the changes in the reactor pressure vessel (RPV) material during operation. Exposure to irradiation (or elevated temperatures) causes the segregation of phosphorus to internal grain boundaries in RPV steels. This, in turn, encourages brittle intergranular failure of the material. The PISA project had the objective of reducing the uncertainties associated with the impact of this failure mechanism on the properties of the RPV, both during service and at the end-of-life. This report presents the experimental results on the segregation of P and C during irradiation and thermal treatments, and the associated mechanical property changes, generated within PISA. The new data cover a range of bulk P levels, irradiation temperatures and fluences, steel types and product forms. In all cases only modest increases of P level on the grain boundary have been observed in commercial steels. Segregation is higher in pre-strained than in unstrained material. In addition a model for P segregation under irradiation has been developed, and shown to be capable of fitting the experimentally observed changes in P level after irradiation. Significant insight into the development of the microstructure under irradiation has thereby been obtained. Overall, the data and modelling together indicated that relatively small amounts of segregation are likely to occur under most reactor operational conditions in homogeneous commercial steels, and an (unexpectedly) small amount of additional embrittlement likely to derive from this process during reactor service.JRC.F.4-Nuclear design safet

Prototype Testing Results of Charged Particle Detectors and Critical Subsystems for the ESRA Mission to GTO

The Experiment for Space Radiation Analysis (ESRA) is the latest of a series of Demonstration and Validation (DemVal) missions built by the Los Alamos National Laboratory, with the focus on testing a new generation of plasma and energetic paritcle sensors along with critical subsystems. The primary motivation for the ESRA payloads is to minimize size, weight, power, and cost while still providing necessary mission data. These new instruments will be demonstrated by ESRA through ground-based testing and on-orbit operations to increase their technology readiness level such that they can support the evolution of technology and mission objectives. This project will leverage a commercial off-the-shelf CubeSat avionics bus and commercial satellite ground networks to reduce the cost and timeline associated with traditional DemVal missions. The system will launch as a ride share with the DoD Space Test Program to be inserted in Geosynchronous Transfer Orbit (GTO) and allow observations of the Earth\u27s radiation belts. The ESRA CubeSat consists of two science payloads and several subsystems: the Wide field-of-view Plasma Spectrometer, the Energetic Charged Particle telescope, high voltage power supply, payload processor, flight software architecture, and distributed processor module. The ESRA CubeSat will provide measurements of the plasma and energetic charged particle populations in the GTO environment for ions ranging from ~100 eV to ~1000 MeV and electrons with energy ranging from 100 keV to 20 MeV. ESRA will utilize a commercial 12U bus and demonstrate a low-cost, rapidly deployable spaceflight platform with sufficient SWAP to enable efficient measurements of the charged particle populations in the dynamic radiation belts

The Experiment for Space Radiation Analysis: Probing the Earth\u27s Radiation Belts Using a CubeSat Platform

The Experiment for Space Radiation Analysis (ESRA) is the latest of a series of Demonstration and Validation missions built by the Los Alamos National Laboratory, with the focus on testing a new generation of plasma and energetic particle sensors. The primary motivation for the ESRA payloads is to minimize size, weight, power, and cost while still providing necessary mission data. These new instruments will be demonstrated by ESRA through testing and on-orbit operations to increase their technology readiness level such that they can support the evolution of technology and mission objectives. This project will leverage a commercial off-the-shelf CubeSat avionics bus and commercial satellite ground networks to reduce the cost and timeline associated with traditional DemVal missions. The system will launch as a ride share with the DoD Space Test Program to be inserted in Geosynchronous Transfer Orbit (GTO) and allow observations of the Earth’s radiation belts. The ESRA CubeSat consists of two science payloads and several subsystems: the Wide-field-of-view Plasma Spectrometer, the Energetic Charged Particle telescope, high voltage power supply, payload processor, flight software architecture, and distributed processor module. The ESRA CubeSat will provide measurements of the plasma and energetic charged particle populations in the GTO environment for ions ranging from ~100 eV to ~1000 MeV and electrons with energy ranging from 100 keV to 20 MeV. ESRA will utilize a commercial 12U bus and demonstrate a low-cost, rapidly deployable spaceflight platform with sufficient SWAP to enable efficient measurements of the energetic particle populations in the dynamic radiation belts

The EBM-DPSER conceptual model: integrating ecosystem services into the DPSIR framework

There is a pressing need to integrate biophysical and human dimensions science to better inform holistic ecosystem management supporting the transition from single species or single-sector management to multi-sector ecosystem-based management. Ecosystem-based management should focus upon ecosystem services, since they reflect societal goals, values, desires, and benefits. The inclusion of ecosystem services into holistic management strategies improves management by better capturing the diversity of positive and negative human-natural interactions and making explicit the benefits to society. To facilitate this inclusion, we propose a conceptual model that merges the broadly applied Driver, Pressure, State, Impact, and Response (DPSIR) conceptual model with ecosystem services yielding a Driver, Pressure, State, Ecosystem service, and Response (EBM-DPSER) conceptual model. The impact module in traditional DPSIR models focuses attention upon negative anthropomorphic impacts on the ecosystem; by replacing impacts with ecosystem services the EBM-DPSER model incorporates not only negative, but also positive changes in the ecosystem. Responses occur as a result of changes in ecosystem services and include inter alia management actions directed at proactively altering human population or individual behavior and infrastructure to meet societal goals. The EBM-DPSER conceptual model was applied to the Florida Keys and Dry Tortugas marine ecosystem as a case study to illustrate how it can inform management decisions. This case study captures our system-level understanding and results in a more holistic representation of ecosystem and human society interactions, thus improving our ability to identify trade-offs. The EBM-DPSER model should be a useful operational tool for implementing EBM, in that it fully integrates our knowledge of all ecosystem components while focusing management attention upon those aspects of the ecosystem most important to human society and does so within a framework already familiar to resource managers

A MICROSTRUCTURE-BASED PROBABILISTIC MODEL FOR CLEAVAGE IN RPV STEELS

ABSTRACT In both simple ferrite-carbide materials, and more complex ferritic steels, cleavage is mediated by the fracture of the particles they contain. If particle cracking is easy, then extension of the resulting particle-sized microcracks into the ferrite matrix, can become the critical step in inducing fracture. Under these circumstances, brittle fracture is essentially stress-controlled, and several models use this as a basis for failure prediction. Fracture toughness data from a series of MnMoNi steels are presented, together with observations of fracture initiation sites, and calculations of the stresses and strains pertaining to these locations at failure, to show that there are circumstances under which particle cracking is not easy. A strain criterion is found to describe the probability of particle cracking effectively. A previouslypublished, stress-based model is generalised to include the strain criterion. The more general model correlates initiation site properties with K, and predicts a marked temperaturedependence of K (i.e. a ductile-to-brittle transition), even though the only temperature-dependent input parameters are the flow properties. Other input parameters for the model are linked explicitly to the microstructure. The relative dominance of particle cracking and microcrack extension in cleavage depends most strongly on initiating particle type, and final quench severity. Keywords Cleavage, reactor pressure vessel steel, model Nomenclature A * Critical area over which σ * must be exceeded in RKR model DBT ductile-to-brittle transition DBTT ductile to brittle transition temperature E Young's modulus of matrix F Fraction of particles taking part in fracture K Facture toughness n work hardening exponent N particles number density P(c ) probability that a particle in a volume element has cracked P f probability of failure P(r 0 ) probability that r>r 0 P(r max >r≥r 0 ) probability that r is between r max and r 0 P(ε particle ≥ε min ) probability that the strain in the particle is greater than ε min P(µe) probability of microcrack extension r size of particle / microcrack r 0 size of microcrack which will extend under locallyapplied stresses r max maximum size of particle remaining uncracked after quenching T temperature T ∞ temperature at which cleavage becomes impossible X distance ahead of precrack tip X c distance between precrack tip and fracture initiation site X p location of peak in tensile stress field X(r=r max )location at which r=r ma

Metastatic Breast Cancer Collateral Damage Project (MBCCD): Scale development and preliminary results of the Survey of Health, Impact, Needs, and Experiences (SHINE)

PURPOSE:Until recently, people with metastatic breast cancer (MBC) had a very poor prognosis. New treatment approaches have prolonged the time that people with MBC live, but their quality of life has received less attention. Consequently, the needs and concerns across financial, vocational, psychological, social, and physical domains in MBC patients are poorly understood-particularly regarding the collateral damage or longer-term, life-altering impacts of MBC and its treatments. This study's aims were to characterize MBC-related collateral damage, identify groups most likely to experience collateral damage, and examine its associations with psychological health, illness management, and health behaviors. METHODS:Participants (N = 515) with MBC were recruited from Dr. Susan Love Research Foundation's Army of Women® and other advocacy organizations. Participants completed questionnaires of MBC-related collateral damage, depressive symptoms, anxiety, self-efficacy for managing oncologic treatments and physical symptoms, sleep, and physical activity. RESULTS:Eight domains of MBC-related collateral damage, as well as MBC-related benefit finding, were reliably characterized. Concerns about mortality/uncertainty were most prominent. Participants also endorsed high levels of benefit finding. Participants younger than 50 years, with limited financial resources, or with children under 18 at home reported the most collateral damage. Collateral damage was associated significantly with compromised psychological health, lower illness management efficacy, and poorer health behaviors, beyond sociodemographic and medical characteristics. CONCLUSIONS:Subgroups of MBC patients report long-term, life-altering consequences of MBC and its treatments, which relate to important health outcomes. Clinical implications and recommendations are discussed