The outlook for precipitation measurements from space

To provide useful precipitation measurements from space, two requirements must be met: adequate spatial and temporal sampling of the storm and sufficient accuracy in the estimate of precipitation intensity. Although presently no single instrument or method completely satisfies both requirements, the visible/IR, microwave radiometer and radar methods can be used in a complementary manner. Visible/IR instruments provide good temporal sampling and rain area depiction, but recourse must be made to microwave measurements for quantitative rainfall estimates. The inadequacy of microwave radiometer measurements over land suggests, in turn, the use of radar. Several recently developed attenuating-wavelength radar methods are discussed in terms of their accuracy, dynamic range and system implementation. Traditionally, the requirements of high resolution and adequate dynamic range led to fairly costly and complex radar systems. Some simplications and cost reduction can be made; however, by using K-band wavelengths which have the advantages of greater sensitivity at the low rain rates and higher resolution capabilities. Several recently proposed methods of this kind are reviewed in terms of accuracy and system implementation. Finally, an adaptive-pointing multi-sensor instrument is described that would exploit certain advantages of the IR, radiometric and radar methods

DCFPAK: Dose coefficient data file package for Sandia National Laboratory

The FORTRAN-based computer package DCFPAK (Dose Coefficient File Package) has been developed to provide electronic access to the dose coefficient data files summarized in Federal Guidance Reports 11 and 12. DCFPAK also provides access to standard information regarding decay chains and assembles dose coefficients for all dosimetrically significant radioactive progeny of a specified radionuclide. DCFPAK was designed for application on a PC but, with minor modifications, may be implemented on a UNIX workstation

On the use of age-specific effective dose coefficients in radiation protection of the public

Current radiation protection standards for the public include a limit on effective dose in any year for individuals in critical groups. This paper considers the question of how the annual dose limit should be applied in controlling routine exposures of populations consisting of individuals of all ages. The authors assume that the fundamental objective of radiation protection is limitation of lifetime risk and, therefore, that standards for controlling routine exposures of the public should provide a reasonable correspondence with lifetime risk, taking into account the age dependence of intakes and doses and the variety of radionuclides and exposure pathways of concern. Using new calculations of the per capita (population-averaged) risk of cancer mortality per unit activity inhaled or ingested in the US Environmental Protection Agency`s Federal Guidance Report No. 13, the authors show that applying a limit on annual effective dose only to adults, which was the usual practice in radiation protection of the public before the development of age-specific effective dose coefficients, provides a considerably better correspondence with lifetime risk than applying the annual dose limit to the critical group of any age

Experimental validation of Monte Carlo calculations for organ dose

The problem of validating estimates of absorbed dose due to photon energy deposition is examined. The computational approaches used for the estimation of the photon energy deposition is examined. The limited data for validation of these approaches is discussed and suggestions made as to how better validation information might be obtained. (ACR

In vivo biodistribution of 125IPIP and internal dosimetry of 123IPIP radioiodinated agents selective to the muscarinic acetylcholinergic receptor complex

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134943/1/mp8941.pd

Environmental acceptability of high-performance alternatives for depleted uranium penetrators

The Army`s environmental strategy for investigating material substitution and management is to measure system environmental gains/losses in all phases of the material management life cycle from cradle to grave. This study is the first in a series of new investigations, applying material life cycle concepts, to evaluate whether there are environmental benefits from increasing the use of tungsten as an alternative to depleted uranium (DU) in Kinetic Energy Penetrators (KEPs). Current military armor penetrators use DU and tungsten as base materials. Although DU alloys have provided the highest performance of any high-density alloy deployed against enemy heavy armor, its low-level radioactivity poses a number of environmental risks. These risks include exposures to the military and civilian population from inhalation, ingestion, and injection of particles. Depleted uranium is well known to be chemically toxic (kidney toxicity), and workplace exposure levels are based on its renal toxicity. Waste materials containing DU fragments are classified as low-level radioactive waste and are regulated by the Nuclear Regulatory Commission. These characteristics of DU do not preclude its use in KEPs. However, long-term management challenges associated with KEP deployment and improved public perceptions about environmental risks from military activities might be well served by a serious effort to identify, develop, and substitute alternative materials that meet performance objectives and involve fewer environmental risks. Tungsten, a leading candidate base material for KEPS, is potentially such a material because it is not radioactive. Tungsten is less well studied, however, with respect to health impacts and other environmental risks. The present study is designed to contribute to the understanding of the environmental behavior of tungsten by synthesizing available information that is relevant to its potential use as a penetrator

A Blood Circulation Model for Reference Man

A dynamic blood circulation model that predicts the movement and gradual dispersion of a bolus of material in the circulation after its intravenous injection into an adult human. The main purpose of the model is improve the dosimetry of internally deposited radionuclides that decay in the circulation to a significant extent. The model partitions the blood volume into 24 separate organs or tissues, right heart chamber, left heart chamber, pulmonary circulation, arterial outflow to the aorta and large arteries, and venous return via the large veins. Model results were compared to data obtained from injection of carbon 11 labeled carbon monoxide or rubidium 86

Улучшенные модели оценки радиационного риска для отдельных когорт пациентов в Швеции

In radiological diagnostics and therapy, it is important that practitioners, referrers, (i.e. radiologists, radiation oncologists and others in health-care) are aware of how much radiation a patient may receive from the various procedures used and associated health risk. The profession has a duty to inform patients or their representatives of the advantages and disadvantages of specific investigations or treatment plans. The need to estimate and communicate risks in connection with medical use of ionizing radiation is highlighted e.g. in the Russian Federation State Law No 3, §17.2,1996 and in the EU directive (2013/59/EURATOM 2014). The most commonly used way to express harm in relation to low doses of ionizing radiation is use of the quantity effective dose (E). Effective dose, a radiation protection quantity, however is not intended to provide risk estimates for medical exposures. Its purpose is to optimize conditions for radiation workers (18-65 years) or the general public; all groups with age distributions that differ from patients. In this paper the lifetime attributable risk was used to estimate the excess risk of receiving and dying of radiogenic cancer. The lifetime attributable risk estimations are generated from three different variables, gender, attained age and age at exposure giving the possibility to create age and gender specific cancer risk estimations. Initially, the US Environmental Protection Agency lifetime attributable risk coefficients which are intended to predict the cancer risk from ionizing radiation to a normal US population were applied. In this work, the lifetime attributable risk predictions were modified to the normal Swedish population and to cohorts of Swedish patients undergoing radiological and nuclear medicine examinations or treatments with survival times that differfrom the normal population. For Swedish males, all organs were given the same absorbed dose, exposed at 20, 40 and 70 years, the lifetime attributable risk coefficients (Gy-1) were 0.11, 0.068, and 0.038, respectively, which is lower than the corresponding figures for US males, 0.13, 0.077, and 0.040. For Swedish females, all organs were given the same absorbed dose, exposed at 40 years of age with a diagnosis of breast, colon or liver cancer, the lifetime attributable risk coefficients are 0.064, 0.034, and 0.0038, respectively, which is much lower than if a 40 years female without known cancer is exposed, 0.073.В лучевой диагностике и терапии крайне важно, чтобы медицинский персонал (врачи-рентгенологи, лечащие врачи, радиационные онкологи и пр.) имели представление о том, какую дозу облучения получил пациент от различных рентгенорадиологических исследований и с каким риском для здоровья эта доза связана. Медицинский персонал несет ответственность за информирование пациентов и их законных представителей о достоинствах и недостатках выбранных исследований или планов лечения. Так, например, необходимость оценки и коммуникации рисков в контексте использования ионизирующего излучения в медицине особо отмечена в Федеральном законе ФЗ-3 «О радиационной безопасности населения» в Россйской Федерации и в директиве Евросоюза 2013/59/EURATOM 2014. Наиболее распространенным способом выражения вреда от низких доз ионизирующего излучения является использование эффективной дозы, которая, хотя и является основной величиной в радиационной защите, не предназначена для оценки рисков от медицинского облучения. Ее задачей является обеспечение оптимизации радиационной защиты персонала (людей в возрасте 18—65лет) и населения — групп с возрастным распределением, резко отличающимся от возрастных распределений пациентов. В данном исследовании величина пожизненного атрибутивного риска была использована для оценки избыточного риска получить и умереть от радиогенного рака различной нозологии. Оценки значений пожизненного атрибутивного риска основывались на трех переменных: пол, возраст дожития и возраст при облучении, что позволило определить риски развития радиогенного рака с учетом пола и возраста пациентов. Изначально были использованы коэффициенты пожизненного атрибутивного риска, разработанные Агентством по защите окружающей среды США, которые позволяют оценить избыточные радиогенные раки для нормальной популяции США. В данной работе значения коэффициентов пожизненного атрибутивного риска были изменены с учетом специфики здорового шведского населения, а также когорт шведских пациентов, проходящих различные рентгенорадиологические исследования и курсы лучевой терапии, время дожития которых существенно отличалось от такового для обычного населения. Для шведских мужчин, при условии, что все органы организма получили одну и ту же поглощенную дозу и облучение произошло в возрасте 20, 40 и 70 лет, соответствующие коэффициенты пожизненного атрибутивного риска (Гр-1) составили 0,11, 0,068, и 0,038 соответственно, что ниже по сравнению с аналогичными данными для американских мужчин — 0,13, 0,077, и 0,040 соответственно. Для шведских женщин, при условии, что все органы организма получили одну поглощенную дозу и облучение произошло в возрасте 40 лет с диагнозом рака груди, прямой кишки или печени, коэффициенты пожизненного атрибутивного риска (Гр-1) составили 0,064, 0,034, и 0,0038 соответственно, что существенно ниже значения 0,073 в случае облучения 40-летних женщин, у которых диагноз рака установлен не был

The Procedure for Determining and Quality Assurance Program for the Calculation of Dose Coefficients Using DCAL Software

The development of a spallation neutron source with a mercury target may lead to the production of rare radionuclides. The dose coefficients for many of these radionuclides have not yet been published. A collaboration of universities and national labs has taken on the task of calculating dose coefficients for the rare radionuclides using the software package: DCAL. The working group developed a procedure for calculating dose coefficients and a quality assurance (QA) program to verify the calculations completed. The first portion of this QA program was to verify that each participating group could independently reproduce the dose coefficients for a known set of radionuclides. The second effort was to divide the group of radionuclides among the independent participants in a manner that assured that each radionuclide would be redundantly and independently calculated. The final aspect of this program was to resolve any discrepancies arising among the participants as a group of the whole. The output of the various software programs for six QA radionuclides, 144Nd, 201Au, 50V, 61Co, 41Ar, and 38S were compared among all members of the working group. Initially, a few differences in outputs were identified. This exercise identified weaknesses in the procedure, which have since been revised. After the revisions, dose coefficients were calculated and compared to published dose coefficients with good agreement. The present efforts involve generating dose coefficients for the rare radionuclides anticipated to be produced from the spallation neutron source should a mercury target be employed

An Interdatabase Comparison of Nuclear Decay and Structure Data Utilized in the Calculation of Dose Coefficients for Radionuclides Produced in a Spallation Neutron Source

Internal and external dose coefficient values have been calculated for 14 anthropogenic radionuclides which are not currently presented in Federal Guidance Reports Nos. 11, 12, and 13 or Publications 68 and 72 of the International Commission on Radiological Protection. Internal dose coefficient values are reported for inhalation and ingestion of 1 μm and 5 μm AMAD particulates along with the f1 values and absorption types for the adult worker. Internal dose coefficient values are also reported for inhalation and ingestion of 1 μm AMAD particulates as well as the f1 values and absorption types for members of the public. Additionally, external dose coefficient values for air submersion, exposure to contaminated ground surface, and exposure to soil contaminated to an infinite depth are also presented. Information obtained from this study will be used to support the siting and permitting of future accelerator-driven nuclear initiatives within the U.S. Department of Energy complex, including the Spallation Neutron Source (SNS) and Accelerator Production of Tritium (APT) Projects