Recent integral cross section validation measurements at the ASP facility

This work presents new integral data measured at the ASP 14 MeV neutron irradiation facility at Aldermaston in the UK, which has recently become available for fusion-related work through the CCFE materials programme. Measurements of reaction products from activation experiments using elemental foils were carried out using gamma spectrometry in a high efficiency, high-purity germanium (HPGe) detector and associated digital signal processing hardware. Following irradiation and rapid extraction to the measurement cell, gamma emissions were acquired with both energy and time bins. Integral cross section and half-life data have been derived from these measurements. Selected integral cross section values are presented from the measurement campaigns.Comment: 4 pages, 5 figure

Analysis of TNFAIP3, a feedback inhibitor of nuclear factor-κB and the neighbor intergenic 6q23 region in rheumatoid arthritis susceptibility

Introduction Genome-wide association studies of rheumatoid arthritis (RA) have identified an association of the disease with a 6q23 region devoid of genes. TNFAIP3, an RA candidate gene, flanks this region, and polymorphisms in both the TNFAIP3 gene and the intergenic region are associated with systemic lupus erythematosus. We hypothesized that there is a similar association with RA, including polymorphisms in TNFAIP3 and the intergenic region. Methods To test this hypothesis, we selected tag-single nucleotide polymorphisms (SNPs) in both loci. They were analyzed in 1,651 patients with RA and 1,619 control individuals of Spanish ancestry. Results Weak evidence of association was found both in the 6q23 intergenic region and in the TNFAIP3 locus. The rs582757 SNP and a common haplotype in the TNFAIP3 locus exhibited association with RA. In the intergenic region, two SNPs were associated, namely rs609438 and rs13207033. The latter was only associated in patients with anti-citrullinated peptide antibodies. Overall, statistical association was best explained by the interdependent contribution of SNPs from the two loci TNFAIP3 and the 6q23 intergenic region. Conclusions Our data are consistent with the hypothesis that several RA genetic factors exist in the 6q23 region, including polymorphisms in the TNFAIP3 gene, like that previously described for systemic lupus erythematosus

Respiratory Syncytial Virus Matrix Protein Induces Lung Epithelial Cell Cycle Arrest through a p53 Dependent Pathway

Respiratory syncytial virus (RSV) is the major cause of viral respiratory infections in children. Our previous study showed that the RSV infection induced lung epithelial cell cycle arrest, which enhanced virus replication. To address the mechanism of RSV-induced cell cycle arrest, we examined the contribution of RSV-matrix (RSV-M) protein. In this report, we show that in both the A549 cell line and primary human bronchial epithelial (PHBE) cells, transfection with RSV-M protein caused the cells to proliferate at a slower rate than in control cells. The cell cycle analysis showed that RSV-M protein induced G1 phase arrest in A549 cells, and G1 and G2/M phase arrest in PHBE cells. Interestingly, RSV-M expression induced p53 and p21 accumulation and decreased phosphorylation of retinoblastoma protein (Rb). Further, induction of cell cycle arrest by RSV-M was not observed in a p53-deficient epithelial cell line (H1299). However, cell cycle arrest was restored after transfection of p53 cDNA into H1299 cells. Taken together, these results indicate that RSV-M protein regulates lung epithelial cell cycle through a p53-dependent pathway, which enhances RSV replication

Rheumatoid arthritis response to treatment across IgG1 allotype - anti-TNF incompatibility: a case-only study.

INTRODUCTION: We have hypothesized that incompatibility between the G1m genotype of the patient and the G1m1 and G1m17 allotypes carried by infliximab (INX) and adalimumab (ADM) could decrease the efficacy of these anti-tumor necrosis factor (anti-TNF) antibodies in the treatment of rheumatoid arthritis (RA). METHODS: The G1m genotypes were analyzed in three collections of patients with RA totaling 1037 subjects. The first, used for discovery, comprised 215 Spanish patients. The second and third were successively used for replication. They included 429 British and Greek patients and 393 Spanish and British patients, respectively. Two outcomes were considered: change in the Disease Activity Score in 28 joint (ΔDAS28) and the European League Against Rheumatism (EULAR) response criteria. RESULTS: An association between less response to INX and incompatibility of the G1m1,17 allotype was found in the discovery collection at 6 months of treatment (P = 0.03). This association was confirmed in the replications (P = 0.02 and 0.08, respectively) leading to a global association (P = 0.001) that involved a mean difference in ΔDAS28 of 0.4 units between compatible and incompatible patients (2.3 ± 1.5 in compatible patients vs. 1.9 ± 1.5 in incompatible patients) and an increase in responders and decrease in non-responders according to the EULAR criteria (P = 0.03). A similar association was suggested for patients treated with ADM in the discovery collection, but it was not supported by replication. CONCLUSIONS: Our results suggest that G1m1,17 allotypes are associated with response to INX and could aid improved therapeutic targeting in RA

Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry

OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc). METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers. RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group. CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies

Fusion power : safety and environmental analysis using integrated, three-dimensional computer modelling

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Activation properties of tungsten as a first wall protection in fusion power plants”, Fusion Engineering and Design

Abstract Tungsten is a candidate material for a protective armour on the plasma-facing first wall of a fusion power plant. In order to assess the radiological implications of this use of tungsten, two power plant models from the European Power Plant Conceptual Study (PPCS) have been extended by the addition of a 2 mm tungsten layer on the ferriticmartensitic first wall. Neutronics and activation modelling have shown that there is no significant impact on the favourable conclusions regarding long-term disposal of materials, but that earlier activity levels could potentially be of importance on the timescale of maintenance operations. The short-term activity and decay are expected to have only a minor impact on the consequences of postulated accidents. Keywords Neutron activation, tungsten, first wall armour, dose rate, decay heat, fusion power plant 2 1 Introduction Studies of future fusion power plant design concepts in the European Power Plant Conceptual Study (PPCS) This material is employed as blanket structure, including the plasma-facing first wall surface. It may be desirable to protect this Eurofer surface from erosion by provision of a protective armour layer, either as a coating or as tiles. One candidate for such an armour is tungsten, attractive by virtue of its expected low sputtering and erosion rate. But exposure to a high flux of 14 MeV neutrons from the plasma, as well as lower energy neutrons returning from the blanket after moderation, raises the issue of activation of this tungsten layer and the possibility of radiological consequences. In this work the neutron activation has been calculated in a tungsten armour layer added to two of the PPCS plant models, and the implications for safety, environmental impact and operation are assessed. The two models, labelled Plant Models A and B in the PPCS study, are chosen to represent a water-cooled and a helium-cooled concept, in order that any influence of the different blanket neutron spectra can be observed. Calculations performed The activation behaviour of a 2 mm-thick layer of tungsten has been studied by extending existing neutronic models of PPCS Plant Models A and B. Both assume Eurofer structure, which will have a similar influence on the neutron spectra in the vicinity of the first wall for both models, but whereas Model B has helium-cooled first 3 wall and blanket, Model A is water-cooled which could lead to a softer neutron spectrum through greater moderation. The neutronics calculations were performed with the MCNP code (version 4C3) and ENDF/B-VI cross section data, using 3-D models previously generated for PPCS safety and environmental analyses using the in-house HERCULES code system Special care was taken to correctly calculate the contribution of the reaction 186 W(n,γ) 187 W, which has a giant resonance at about 20eV. Due to resonance selfshielding, the use of multigroup cross sections and group fluxes is likely to lead to an over-estimation of 187 W production via this resonance capture. To ensure a correct evaluation, the 186 W(n,γ) reaction rate was computed directly in the MCNP continuousenergy calculation, and this value transferred to the FISPACT code for the inventory calculation. The magnitude of the effect is geometry-dependent, with thicker tungsten regions leading to more pronounced self-shielding; nevertheless, even in a 2 mm layer the effect was found to be significant. 4 A comparison was made of the total activation results for tungsten with this correct procedure and with a purely multigroup calculation. In the FISPACT calculations, the irradiation history assumed that the first wall lifetime is 5 full power years -the armour was also assumed to be exposed for this period. At the end of the first 2.5 years operation there is a shutdown for 2 months for divertor replacement, followed by a further 2.5 years operation. After the end of this lifetime, the inventory, activation and all related quantities were calculated at decay times from 1 second up to 10,000 years. Results Activation results The specific activity of the tungsten material after the end of operation is shown in dose rate at early times could also have an impact on maintenance operations. The contact gamma dose rate is above 10,000 Sv/hr for around 6 months after shutdown, which could be a challenge for some remote handling equipment. Although this result for tungsten is initially around three times that for Eurofer, beyond this 6-month point it falls to lower values -however, this is too late to be of benefit for maintenance procedures. The decay heat density of the tungsten after the end of operation is shown in Waste categorisation Based on the results of the activation calculations presented above, it is possible to categorise the active tungsten according to the criteria adopted in PPCS and earlier European studies [5]. These define categories for non-active waste (below Clearance limits), simple and complex recycling material, and permanent disposal waste. The Clearance level is never reached by the tungsten armour material, and the simple recycling level only after several hundreds of years. So the only relevant categories are 7 complex recycling material and permanent disposal waste. The material is categorised for permanent disposal if the contact gamma dose-rate is above 20 mSv/hr or the decay heat is above 10 W/m 3 . These limits are somewhat arbitrary, and the 20 mSv/hr limit is now believed to be conservative, but it has been adopted by PPCS in common with earlier European fusion safety and environmental assessments [5], pending a reevaluation. The tungsten armour falls below the 20 mSv/hr level after about 75 years ( The total mass of tungsten, less than 300 tonnes, is only a relatively minor addition to the total masses of material arising from Plant Models A and B. The presence of the 2 mm tungsten armour has an insignificant effect on the activation levels in other components due to neutron absorption in the tungsten itself; comparison of the MCNP results with and without the armour layer showed that the total neutron flux at the back of the first wall is reduced by just 0.7% when the tungsten is added. Conclusions The addition of a 2 mm tungsten armour layer to the plasma-facing surface of the Eurofer first wall has been analysed for its neutron activation behaviour. The decay 8 heat in the short term (~1 day) following shutdown is modest, and unlikely to give rise to any problems in postulated accidents. The relatively high activity at these early times may be significant for accident scenarios in which in-vessel dust, formed mainly of material from the plasma-facing surface, is a potential source term. The dose rates from tungsten armour, both direct and through inhalation, are initially around three times higher than those from an equivalent mass of Eurofer first wall exposed without tungsten armour. For the first few months after shutdown the contact gamma dose rate remains relatively high, but falls below that of Eurofer after six months. The high dose at the times that maintenance operations would be in progress could conceivably be an issue for some remote handling equipment that is sensitive to operation in a radiation field. After the end of plant life and up to 50 years later, the activation properties of the tungsten material are such that only a small proportion is categorised as suitable for recycling. But some 75 years after end of plant life, all of the tungsten material has a contact gamma dose-rate that has fallen below the 20 mSv/hr level, allowing it to be categorised as complex recycling material. A key outcome of the earlier studies in PPCS was that for all four Plant Models there is no material requiring permanent disposal after 100 years

DW-I Revision of the radioactive waste analysis of ITER-relevant PPCS models

Abstract.-A sound approach to the recycling of fusion irradiated material based on industry experience in the field is being developed. The study of realistic processing routes and techniques provides a sensible estimation of recycling feasibility. The radioactive waste analysis of two models in the Power Plant Conceptual Study, PPCS, is being revised under this approach with increased detail and accounting for the latest design features, nuclear data and international guidelines. The models analysed are two near-term ones based on the helium-cooled liquid and solid breeder blanket concepts, extrapolated from ITER test blanket modules (TBMs). The radiological characteristics of the waste inventory have been re-assessed for all structures in the tokamaks, for the first time studying individual constituents and materials. Results illustrate how a stringent impurity control simplifies recycling processes and reduces long-lived secondary wastes; preliminary guidelines for this control have been produced. Discussion is made of optimisation methods and potential routes for waste streams