WorldWideScience

Sample records for air kerma standardization

  1. Recent developments and current status of air kerma standards

    International Nuclear Information System (INIS)

    Primary Standard Dosimetry Laboratories (PSDL) usually maintain air kerma standards for kilovoltage x-rays (10 kV to 300 kV) and for 137Cs- and 60Co-γ radiation. Free-air ionisation chambers (FAC) and cavity ionisation chambers are used as primary air kerma standards for kilovoltage x-rays and for 137Cs- and 60Co-γ radiation, respectively. The majority of the National Metrology Institutes (NMIs) signed the Mutual Recognition Arrangement (MRA) of national measurement standards and of calibration and measurement certificates issued by NMIs. The MRA has been available for signature since 14th October 1999. According to the MRA, the signatories participate in CIPM key comparisons executed by the Consultative Committees or the BIPM, leading to a key comparison reference value. The degree of equivalence of a national measurement standard is expressed quantitatively in terms of its deviation from the key comparison reference value and the uncertainty of this deviation. For air kerma standards the Consultative Committee for Ionising Radiation (CCRI(I)) currently maintains three types of key comparisons and a so-called supplementary comparison. The air kerma key comparisons are organised bilaterally and are carried out between the air kerma standards of the BIPM and the participating NMIs. The radiations used are low-energy (10 kV to 50 kV) and medium energy (100 kV to 250 kV) x-ray beams and 137Cs- and 60Co-γ radiation. To be entitled to enter the key comparison database with respect to air kerma an NMI has to participate in a key comparison within a time period of 10 years. In keeping with the longstanding method of presenting the data, the CCRI(I) took the decision at its meeting in 1999 to use the BIPM determination of air kerma rate as the key comparison reference value. For this reason the BIPM air kerma standards are of special importance. Due to the fact that the air kerma key comparisons have been conducted on an ongoing basis since 1966 for low-energy x

  2. Status of air kerma and absorbed dose standards in India

    International Nuclear Information System (INIS)

    Full text: The Radiation Safety Systems Division of Bhabha Atomic Research Centre, India maintains Primary and Secondary Standards of various parameters of radiation measurements and provides calibration services to various users of radiation in the country. This is an apex laboratory in India and plays a pivotal role in ensuring accurate radiological measurements. The laboratory coordinates national intercomparisons of radiation measurements to maintain their uniformity and traceability and is linked through various programmes with the other International organizations such as Bureau Internationale des Poids et Mesures (BIPM) Paris, International Atomic Energy Agency (IAEA) Vienna, Asia Pacific Metrology Programme (APMP) Taiwan. It is the recognized Regional Secondary Standards Dosimetry Laboratory (SSDL) of IAEA/WHO (World Health Organisation). This paper brings out the status of various primary and secondary standards for radiological measurements maintained at BARC. 1. Primary Exposure/Air-kerma standard at Co-60 energy (therapy level): The primary standard for exposure/ air-kerma measurements maintained at BARC is a graphite cavity chamber of volume 4.362 cc with an internal diameter of 1.8 cm, internal height of 1.78 cm and wall thickness of 704.3mg/cm2. Correction factors for the difference between electron stopping powers, photon mass energy absorption coefficients of air and graphite wall, correction for recombination, radiation field non-uniformity, stem scatter and polarity effect are applied and the maximum overall uncertainty in the realisation of exposure/air-kerma is around ±1%. This standard has been intercompared with IAEA and BIPM through transfer standard and the agreement in the results are better than ±1%. An intercomparison under the APMP programme is to be held during May, 2002. 2. Primary Exposure/Air-kerma standard at protection and brachytherapy level: A set of three spherical graphite-walled cavity chambers of different air-volumes are

  3. Comparison of the NIST and ENEA air kerma standards

    International Nuclear Information System (INIS)

    A comparison was made between the National Institute of Standards and Technology (NIST) and Ente per le Nuov Tecnologie l'Energia e l'Ambiente (ENEA) air kerma standards for medium energy x rays and 60Co gamma rays. The comparison took place at ENEA in June 1994. Two different transfer chambers from NIST were used for the comparison. The measurements were made at radiation qualities similar to those used at the Bureau International des Poids et Mesures (BIPM) (generating voltages of 100 kV, 135 kV, 180 kV and 250 kV, respectively) and with 60Co gamma radiation. The transfer chamber calibration factors obtained at the NIST and at the ENEA agreed with one another to 0.03% for 60Co gamma radiation and between 0.1% to 0.8% for the medium energy x-ray beam codes

  4. Air kerma standardization for diagnostic radiology in a secondary standard laboratory

    International Nuclear Information System (INIS)

    The demand for calibration services and quality control in diagnostic radiology has grown in the country since the publication of the governmental regulation 453, issued by the Brazilian Ministry of Health in 1998. At that time, to produce results facing the new legislation, many laboratories used different standards and radiation qualities, some of which could be inadequate. The international standards neither supplied consistent radiation qualities and standardization for the different types of equipment available. This situation changed with the publication of the new edition of the IEC 61267 standard, published in 2005. The objective of this work was to implement the standardization of the air kerma for the unatenuated qualities (RQR) of IEC 61267 in the National Laboratory of Metrology of the Ionizing Radiations (LNMRI) of the Institute of Radiation Protection and Dosimetry (IRD). Technical procedures were developed together with uncertainty budget. Results of interlaboratory comparisons demonstrate that the quantity is standardized and internationally traceable. (author)

  5. Measurement of air kerma rate and absorbed dose for brachytherapy sources with secondary standard dosimeter

    International Nuclear Information System (INIS)

    The air kerma measurements for brachytherapy sources are generally recommended to be done at one meter using large volume chambers. These measurements pose problems due to low signal from brachytherapy sources. Non-availability of calibrated large volume chambers at a hospital adds to the problem of air kerma measurements. Therefore, the use of commonly available secondary standard dosimeter having 0.6 cc chambers has been examined. Correction factors to be applied at small source to chamber distances have been determined. Measurements from 137Cs source of nominal activity as low as 1.11 GBq (30 mCi) could be carried out using an integration time of about 20 minutes at minimum distance of 1.5 cm. For source to chamber distance beyond 5 cm, the correction factor approaches unity. (author)

  6. A new approach to the determination of air kerma using primary-standard cavity ionization chambers

    International Nuclear Information System (INIS)

    A consistent formalism is presented using Monte Carlo calculations to determine the reference air kerma from the measured energy deposition in a primary-standard cavity ionization chamber. A global approach avoiding the use of cavity ionization theory is discussed and its limitations shown in relation to the use of the recommended value for W. The role of charged-particle equilibrium is outlined and the consequent requirements placed on the calculations are detailed. Values for correction factors are presented for the BIPM air-kerma standard for 60Co, making use of the Monte Carlo code PENELOPE, a detailed geometrical model of the BIPM 60Co source and event-by-event electron transport. While the wall correction factor kwall = 1.0012(2) is somewhat lower than the existing value, the axial non-uniformity correction kan = 1.0027(3) is significantly higher. The use of a point source in the evaluation of kan is discussed. A comparison is made of the calculated dose ratio with the Bragg-Gray and Spencer-Attix stopping-power ratios, the results indicating a preference for the Bragg-Gray approach in this particular case. A change to the recommended value for W of up to 2 parts in 103 is discussed. The uncertainties arising from the geometrical models, the use of phase-space files, the radiation transport algorithms and the underlying radiation interaction coefficients are estimated

  7. Standardization of iridium-192 coiled source in terms of air kerma output

    International Nuclear Information System (INIS)

    ICRU (1985) recommended that the output of gamma ray brachytherapy sources should be specified in terms of reference air kerma rate, defined as the kerma rate to air in air at a reference distance of 1 meter, perpendicular to the long axis of the source, corrected for air attenuation and scattering. As these measurements are difficult to carry out in the routine clinical use, it is the common practice to calibrate the re-entrant ionization chamber with respect to open air measurements and use the re-entrant chamber for routine measurements. This paper reports on the measurements carried out to correlate the nominal activity and air kerma rate of 192Ir wire sources supplied by the Board of Radiation and Isotope Technology, Department of Atomic Energy. (author). 3 refs, 1 tab

  8. Air kerma standardization for diagnostic radiology, and requirements proposal for calibration laboratories

    International Nuclear Information System (INIS)

    The demand for calibration services and quality control in diagnostic radiology has grown in the country since the publication of the governmental regulation 453, issued by the Ministry of Health in 1998. At that time, to produce results facing the new legislation, many laboratories used different standards and radiation qualities, some of which could be inadequate. The international standards neither supplied consistent radiation qualities and standardization for the different types of equipment available. This situation changed with the publication of the new edition of the IEC 61267 standard, published in 2005. A metrology network was created, but it is not yet accredited by the accreditation organism of the country, INMETRO. The objective of this work was to implement the standardization of the air kerma for the un attenuated qualities (RQR) of IEC 61267, and to develop a requirement proposal for instruments calibration laboratories. Results of interlaboratory comparisons demonstrate that the quantity is standardized and internationally traceable. A laboratory requirement proposal was finalized and it shall be submitted to INMETRO to be used as auxiliary normative document in laboratory accreditation. (author)

  9. Comparison of the standards for air kerma of the NMIJ and the BIPM for 60Co γ rays

    International Nuclear Information System (INIS)

    A first comparison of the standards for air kerma of the National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) and of the Bureau International des Poids et Mesures (BIPM) has been carried out in 60Co radiation. It shows that the NMIJ and BIPM standards differ by 0.72 % with a relative standard uncertainty of 2.4 x 10-3. (authors)

  10. Comparison of the standards of air kerma of the OMH and the BIPM for 60Co gamma radiation

    International Nuclear Information System (INIS)

    A direct comparison between the standards for air kerma of the Orszagos Meresugyi Hivatal (OMH) and of the Bureau International des Poids et Mesures (BIPM) has been carried out in the 60Co radiation beams of the BIPM. The result, expressed as a ratio of the OMH and the BIPM standards for air kerma, indicates a relative difference of 10.9 x 10-3 with a combined standard uncertainty of 2.2 x 10-3. This new result agrees at the level of 0.4 x 10-3 with the earlier direct comparisons performed in 1986 and 1994, as modified in 2001 by the application of wall and axial non-uniformity correction factors, calculated for the OMH standards using the Monte Carlo method. (authors)

  11. Study and determination of the national dosimetric standards in terms of air kerma for X-rays radiation fields of low and medium-energies

    International Nuclear Information System (INIS)

    Progress in radiation protection and radiotherapy, and the increased needs in terms of accuracy lead national metrology institutes to improve the standard. For ionizing radiation, the standard is defined by an absolute instrument used for air kerma rate measurement. The aim of the thesis is to establish standards, in terms of air kerma for X-rays beams of low and medium-energies. This work enables to complement the standard beam range of the Laboratoire National Henri Becquerel (LNHB). Two free-air chambers have been developed, WK06 for medium-energy and WK07 for low-energy. The air-kerma rate is corrected by several correction factors. Some are determined experimentally; and the others by using Monte Carlo simulations. The uncertainty budget of the air-kerma rate at one standard deviation has been established. These dosimetric standards were compared with those of counterparts' laboratories and are consistent in terms of degree of equivalence. (author)

  12. Air kerma standardization for diagnostic radiology, and requirements proposal for calibration laboratories; Padronizacao da grandeza Kerma no ar para radiodiagnostico e proposta de requisitos para laboratorios de calibracao

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Manoel Mattos Oliveira

    2009-07-01

    The demand for calibration services and quality control in diagnostic radiology has grown in the country since the publication of the governmental regulation 453, issued by the Ministry of Health in 1998. At that time, to produce results facing the new legislation, many laboratories used different standards and radiation qualities, some of which could be inadequate. The international standards neither supplied consistent radiation qualities and standardization for the different types of equipment available. This situation changed with the publication of the new edition of the IEC 61267 standard, published in 2005. A metrology network was created, but it is not yet accredited by the accreditation organism of the country, INMETRO. The objective of this work was to implement the standardization of the air kerma for the un attenuated qualities (RQR) of IEC 61267, and to develop a requirement proposal for instruments calibration laboratories. Results of interlaboratory comparisons demonstrate that the quantity is standardized and internationally traceable. A laboratory requirement proposal was finalized and it shall be submitted to INMETRO to be used as auxiliary normative document in laboratory accreditation. (author)

  13. COOMET.RI(I)-K1 comparison of national measurement standards of air kerma for 60Co γ radiation

    International Nuclear Information System (INIS)

    Results are presented of the COOMET key comparison of the national measurement standards of air kerma for 60Co γ radiation. Participants of the comparison were PTB (Germany, pilot institute), VNIIM (Russia), SMU (Slovakia), BelGIM (Belarus), CPHR (Cuba) and RMTC (Latvia). PTB, VNIIM and SMU had previously taken part in a key comparison with the Bureau International de Poids et Mesures (BIPM) and operated as link laboratories in order to evaluate the degree of equivalence of the participants' results with the key comparison reference value. These data form the basis of the results entered into the BIPM key comparison database for comparison COOMET.RI(I)-K1. (authors)

  14. Key comparison BIPM.RI(I)-K5 of the air kerma standards of the ININ, Mexico, and the BIPM in 137Cs gamma radiation

    International Nuclear Information System (INIS)

    A direct comparison of the standards for air kerma of the Instituto Nacional de Investigaciones Nucleares (ININ), Mexico, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 137Cs radiation beam of the BIPM in February 2015. The comparison result, evaluated as a ratio of the ININ and the BIPM standards for air kerma, is 1.0048 with a combined standard uncertainty of 2.0 * 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. (authors)

  15. COOMET regional comparison of national measurement standards of air kerma for 137Cs γ radiation at protection level

    International Nuclear Information System (INIS)

    Results are presented of the COOMET supplementary comparison of the national measurement standards for air kerma in 137Cs γ radiation at protection level (∼10 mGy/h). Ten National Metrology Institutes from the COOMET organization and the International Atomic Energy Agency participated in this COOMET project no. 445. The PTB acted as pilot laboratory. Two of the participants, the SMU (Slovakia) and the NSC-'IM' (Ukraine) participated in the measurements but did not submit a valid report of results. The comparison reference value (CRV) was obtained as the mean result of the PTB and the VNIIM, both of which had previously taken part in the key comparison BIPM-RI(I)-K5. The degree of equivalence with the CRV was evaluated. The results were consistent within the relative standard uncertainties of the comparison ranging from 0.28% to 1.3% and deviated from the CRV by less than 1%. (authors)

  16. Study and determination of the national dosimetric standards in terms of air kerma for X-rays radiation fields of low and medium-energies; Etude et realisation des references dosimetriques nationales en termes de kerma dans l'air pour les faisceaux de rayons X de basses et moyennes energies

    Energy Technology Data Exchange (ETDEWEB)

    Ksouri, W

    2008-12-15

    Progress in radiation protection and radiotherapy, and the increased needs in terms of accuracy lead national metrology institutes to improve the standard. For ionizing radiation, the standard is defined by an absolute instrument used for air kerma rate measurement. The aim of the thesis is to establish standards, in terms of air kerma for X-rays beams of low and medium-energies. This work enables to complement the standard beam range of the Laboratoire National Henri Becquerel (LNHB). Two free-air chambers have been developed, WK06 for medium-energy and WK07 for low-energy. The air-kerma rate is corrected by several correction factors. Some are determined experimentally; and the others by using Monte Carlo simulations. The uncertainty budget of the air-kerma rate at one standard deviation has been established. These dosimetric standards were compared with those of counterparts' laboratories and are consistent in terms of degree of equivalence. (author)

  17. COOMET.RI(I)-K1 comparison of national measurement standards of air kerma for {sup 60}Co {gamma} radiation

    Energy Technology Data Exchange (ETDEWEB)

    Buermann, L. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany); Oborin, A.V. [D I Mendeleyev Institute for Metrology (VNIIM), St Petersburg (Russian Federation); Dobrovosky, J. [3 Slovensky Metrologicky Ustav (SMU), Bratislava (Slovakia); Milevsky, V.S. [Belarussian State Institute for Metrology (BelGIM), Minsk (Belarus); Walwyn Salas, G. [Centro de Proteccion e Higiene de las Radiaciones (CPHR), Habana (Cuba); Lapenas, A. [Radiation Metrology and Testing Centre of the Latvian National Metrology Centre Ltd (RMTC), Salaspils (Latvia)

    2009-12-15

    Results are presented of the COOMET key comparison of the national measurement standards of air kerma for {sup 60}Co {gamma} radiation. Participants of the comparison were PTB (Germany, pilot institute), VNIIM (Russia), SMU (Slovakia), BelGIM (Belarus), CPHR (Cuba) and RMTC (Latvia). PTB, VNIIM and SMU had previously taken part in a key comparison with the Bureau International de Poids et Mesures (BIPM) and operated as link laboratories in order to evaluate the degree of equivalence of the participants' results with the key comparison reference value. These data form the basis of the results entered into the BIPM key comparison database for comparison COOMET.RI(I)-K1. (authors)

  18. Calculation of the correction factors for the primary standard of kerma in the air at the LNMRI-IRD, Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    In order to determine the primary standardization in terms of kerma in the air, a graphite ionization chamber is used for calculation some correction factors. A program was elaborated, using the Monte Carlo Penelope for simulate the CC01-110 at the LNMRI/IRD, Rio de Janeiro, Brazil

  19. Comparison BIPM.RI(I)-K8 of high dose-rate Ir-192 brachytherapy standards for reference air kerma rate of the VSL and the BIPM

    DEFF Research Database (Denmark)

    Alvarez, J.T.; De Pooter, J.A.; Andersen, Claus E.;

    2014-01-01

    An indirect comparison of the standards for reference air kerma rate for 192Ir high dose rate brachytherapy sources of the Dutch Metrology Institute (VSL), The Netherlands, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the VSL in November 2009. The comparison resu...

  20. Construction of a laboratory for the implantation of primary standardization of the magnitude kerma in the air for the X-ray beams used in mammography

    International Nuclear Information System (INIS)

    Aiming to diminish the uncertainty in each phase of the metrological chain, and the uncertainty in dosimetry processed at the X-ray beam applied in the mammography, is necessary that the LNMRI/IRD to develop a reference primary standard for the absolute form to the magnitude kerma in the air

  1. Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the NRC, Canada and the BIPM in low-energy x-rays

    International Nuclear Information System (INIS)

    A key comparison has been made between the air-kerma standards of the NRC and the BIPM in the low-energy X-ray range. The results show the standards to be in agreement at the level of the combined standard uncertainty of 2.8 parts in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)

  2. Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the PTB, Germany and the BIPM in low-energy x-rays

    International Nuclear Information System (INIS)

    A key comparison has been made between the air-kerma standards of the PTB, Germany and the BIPM in the low-energy X-ray range. The results show the standards to be in agreement at the level of the standard uncertainty of the comparison of 2.1 parts in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)

  3. Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the BEV, Austria and the BIPM in low-energy x-rays

    International Nuclear Information System (INIS)

    A key comparison has been made between the air-kerma standards of the BEV and the BIPM in the low-energy x-ray range. The results show the standards to be in agreement at the level of the combined standard uncertainty of 4.7 parts in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)

  4. COOMET regional comparison of national measurement standards of air kerma for 137Cs γ radiation at protection level

    Science.gov (United States)

    Büermann, L.; Oborin, A. V.; Milevsky, V. S.; Walwyn Salas, G.; Sukhishvili, S.; Ginga, I.; Ivanov, R.; Gudelis, A.; Gomola, I.

    2014-01-01

    Results are presented of the COOMET supplementary comparison of the national measurement standards for air kerma in 137Cs γ radiation at protection level (~10 mGy/h). Ten National Metrology Institutes from the COOMET organization and the International Atomic Energy Agency participated in this COOMET project no. 445. The PTB acted as pilot laboratory. Two of the participants, the SMU (Slovakia) and the NSC-'IM' (Ukraine) participated in the measurements but did not submit a valid report of results. The comparison reference value (CRV) was obtained as the mean result of the PTB and the VNIIM, both of which had previously taken part in the key comparison BIPM-RI(I)-K5. The degree of equivalence with the CRV was evaluated. The results were consistent within the relative standard uncertainties of the comparison ranging from 0.28% to 1.3% and deviated from the CRV by less than 1%. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  5. Comparison BIPM.RI(I)-K8 of high dose-rate Ir-192 brachytherapy standards for reference air kerma rate of the NMIJ and the BIPM

    Science.gov (United States)

    Kessler, C.; Kurosawa, T.; Mikamoto, T.

    2016-01-01

    An indirect comparison of the standards for reference air kerma rate for 192Ir high dose rate (HDR) brachytherapy sources of the National Metrology Institute of Japan (AIST-NMIJ), Japan, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the Japan Radioisotope Association (JRIA) in April 2015. The comparison result, based on the calibration coefficients for a transfer standard and expressed as a ratio of the NMIJ and the BIPM standards for reference air kerma rate, is 1.0036 with a combined standard uncertainty of 0.0054. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  6. Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the NMIJ and the BIPM in low-energy x-rays

    International Nuclear Information System (INIS)

    A key comparison has been made between the air-kerma standards of the NMIJ and the BIPM in the low-energy X-ray range. The results show the standards to be in agreement within the expanded uncertainty, although there is evidence of a trend in the results for different radiation qualities. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)

  7. Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the NIM, China and the BIPM in 60Co gamma radiation

    Science.gov (United States)

    Kessler, C.; Burns, D.; Wang, K.; Fan, Y.; Jin, S.; Yang, X.

    2016-01-01

    An indirect comparison of the standards for air kerma of the National Institute of Metrology (NIM), China and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in November 2015. The comparison result, evaluated as a ratio of the NIM and the BIPM standards for air kerma, is 0.9997 with a combined standard uncertainty of 2.7 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  8. Comparison of the air kerma standards of the IAEA and the BIPM in mammography x-rays

    Science.gov (United States)

    Kessler, C.; Burns, D. T.; Czap, L.; Csete, I.; Gomola, I.

    2013-01-01

    The Dosimetry Laboratory of the International Atomic Energy Agency (IAEA), Seibersdorf, Austria, calibrates reference standards in mammography x-ray beams for IAEA/WHO SSDL Network members (more than 80 laboratories worldwide). As a signatory of the Mutual Recognition Arrangement (CIPM MRA), the IAEA laboratory maintains a Quality Management System (QMS) complying with ISO 17025 and requires updated 'supporting evidence' for its dosimetry calibration and measurement capabilities (CMC), first published in Appendix C of the CIPM MRA key comparison database in 2007. For this purpose, an indirect comparison has been made between the air kerma standards of the IAEA and the Bureau International des Poids et Mesures (BIPM) in the mammography x-ray range from 25 kV to 35 kV, using as transfer instruments two thin-window parallel-plate ionization chambers belonging to the IAEA. The IAEA and BIPM standards for mammography x-rays are shown to be in agreement within the standard uncertainty of the comparison of 5.5 parts in 103. This agreement can be used to support the calibration and measurements capabilities of the IAEA listed in Appendix C of the key comparison database. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  9. Comparison of the air-kerma standards of the NPL and the BIPM in the low and medium-energy X-ray ranges

    International Nuclear Information System (INIS)

    The air-kerma standards of the NPL and the BIPM have been compared in the low- and medium-energy x-ray ranges. The results for the low-energy comparison show the standards to be in agreement at the level of one standard uncertainty. At medium energies a slight trend with radiation quality is evident, with agreement at the level of one standard uncertainty for 100 kV rising to over two standard uncertainties for 250 kV. In relation to previous comparisons, the good stability of the standards over a period of twenty years is demonstrated. (authors)

  10. Primary standardization of the HDR 192Ir source in terms of air kerma strength

    International Nuclear Information System (INIS)

    Establishing a primary standard of AKS at the Standards Laboratory and offering traceable calibration to all the hospitals that make use of HDR 192Ir, in brachytherapy is important. With this objective, the primary standardization of the HDR 192Ir source was undertaken. Details of the work are presented

  11. Coomet Project 445: Comparison of National Measurement Standards of Air Kerma for Cs-137 Gamma Radiation at Protection Level

    International Nuclear Information System (INIS)

    A COOMET supplementary comparison of the national measurement standards of air kerma for Cs-137 gamma radiation at protection level (∼10 mGy/h) was carried out between May 2011 and February 2013. Participants were VNIIM (Russia), BelGIM (Belarus), CPHR (Cuba), GEOSTM (Georgia), INSM (Moldova), NSC-'IM' (Ukraine), SMU (Slovakia), PTB (Germany), BIM (Bulgaria), VMT/FTMC (Lithuania) and the International Atomic Energy Agency (IAEA). The PTB acted as the pilot laboratory. The comparison reference value (CRV) was obtained as the mean of the results obtained by PTB and VNIIM, both of which had previously taken part in the key comparison BIPM-RI (I)-K5. Results will be published in Appendix B of the BIPM key comparison database (KCDB) using the identifier COOMET.RI(I)-S1 as soon as the Draft B report is accepted. The comparison was organized within an extended COOMET project (identified as Project 445/DE/08), the aim of which was not only to compare national standards but also for educational purposes. Some of the participants had taken part in such a comparison for the first time and, therefore, an introductory seminar was held at PTB in May 2011. The seminar was open for participation also to those countries of the COOMET region which did not participate in the comparison and to nonMRA signatories and countries without an approved quality management system in order to acquire measurement routine and theoretical as well as organizational knowledge for future comparisons. The main goal of this seminar was to prepare the participants for the procedure of having entries accepted for the CMC list in the metrological area of Ionising Radiation, Section I, x and gamma rays

  12. Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the NIST, USA and the BIPM in low-energy x-rays

    International Nuclear Information System (INIS)

    A key comparison has been made between the air-kerma standards of the NIST and the BIPM in the low-energy x-ray range. The results show the standards to be in general agreement at the level of the combined standard uncertainty for the comparison of 4.1 parts in 103, although the results for the different radiation qualities show variations that are larger than would be expected. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)

  13. Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the ARPANSA and the BIPM in low-energy X-rays

    International Nuclear Information System (INIS)

    A key comparison has been made between the air-kerma standards of the ARPANSA and the BIPM in the low-energy X-ray range. The results show the standards to be in agreement at the level of the combined standard uncertainty of 7.0 parts in 103 for the 10 kV radiation quality and 3.7 parts in 103 for all other beam qualities. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)

  14. Air kerma national standard of Russian Federation for x-ray and gamma radiation. Activity SSDL/VNIIM in medical radiation dosimetry field

    International Nuclear Information System (INIS)

    Primary standard of unities air kerma and air kerma rate X-ray and gamma radiation, placed at VNIIM, consists of: plate-parallel free-air ionization chamber IK 10-60 for low-energy X-ray in the generating potential range from 10 to 50 kV; plate-parallel free-air ionization chamber IK 50-400 for medium-energy X-ray in the generating potential range from 50 to 300 kV; cavity cylindrical graphite chambers C1 and C30 with volumes 1 cm3 and 30 cm3 for reproduction and transmission the dimensions gamma radiation unities using Cs-137 and Co-60 sources. The next irradiation facilities are used at VNIIM: in low-energy X-ray range: a constant-potential high-voltage generator and a tungsten-anode Xray tube with inherent filtration of around 1 mm Be; in medium-energy X-ray range: set on the basis of an industrial X-ray apparatus Isovolt-400 and a tungsten-anode X-ray tube with inherent filtration of around 3,5 mm Al; in gamma radiations field: units with a radioactive sources Cs-137 with activity 140 and 1200 GBq and Co-60 with activity 120 GBq and irradiation set with a source from Co-60 (activity 3200 GBq). The last one belongs to Central Research Institute for Radiology and Roentgenology (CNIRRI). For measuring currents and charges of standard chambers we use electrometers such as Keithley of model 6517A and B7-45 manufactured by 'Belvar' (Republic Belarus). The reference radiation qualities L, N, H series according to ISO 4037 and the radiation qualities RQR, RQA and RQF according to IEC 61267 for calibration and verification of the therapeutic, diagnostic measurement means are realized in the low-energy and medium-energy X-ray standards. The VNIIM air kerma primary standard of has been participated in the international comparisons: key comparison BIPM.R1(I)-K1 for gamma radiation of Co-60 in 1997; supplementary comparisons BIPM.R1(I)-S10 for gamma radiation of Cs-137 in 1997; key comparison BIPM.R1(I)-K2 for low-energy X-ray range in 1998; key comparison BIPM.R1(I)-K3 for

  15. Comparisons of the standards for air kerma of the PTB and the BIPM for 60Co and 137Cs gamma radiation

    International Nuclear Information System (INIS)

    Direct comparisons of the standards for air kerma of the Physikalisch-Technische Bundesanstalt (PTB, Germany) and of the Bureau International des Poids et Mesures (BIPM) were carried out in the 60Co and 137 Cs radiation beams of the BIPM in 2000. The results, expressed as ratios of the PTB and the BIPM standards for air kerma, indicate a relative difference in 60Co of 9.9 x 10-3 with a combined standard uncertainty of 1.8 x 10-3, and in 137Cs of 6.4 x 10-3 with a combined standard uncertainty of 2.8 x 10-3. The earlier comparisons in 60Co γ rays made in 1971 (direct) and 1989 (indirect) resulted in an agreement of the two standards within 2 x 10-3. The differences obtained now are due to the application of new correction factors for wall effects and point source non-uniformity of the beam, kwall and kpn, for the PTB standards, which were calculated using Monte Carlo methods. (authors)

  16. Comparisons of the standards for air kerma of the PTB and the BIPM for {sup 60}Co and {sup 137}Cs gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Allisy-Roberts, P.J.; Burns, D.T. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Buermann, L.; Kramer, H.M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    2005-11-15

    Direct comparisons of the standards for air kerma of the Physikalisch-Technische Bundesanstalt (PTB, Germany) and of the Bureau International des Poids et Mesures (BIPM) were carried out in the {sup 60}Co and {sup 137} Cs radiation beams of the BIPM in 2000. The results, expressed as ratios of the PTB and the BIPM standards for air kerma, indicate a relative difference in {sup 60}Co of 9.9 x 10{sup -3} with a combined standard uncertainty of 1.8 x 10{sup -3}, and in {sup 137}Cs of 6.4 x 10{sup -3} with a combined standard uncertainty of 2.8 x 10{sup -3}. The earlier comparisons in {sup 60}Co {gamma} rays made in 1971 (direct) and 1989 (indirect) resulted in an agreement of the two standards within 2 x 10{sup -3}. The differences obtained now are due to the application of new correction factors for wall effects and point source non-uniformity of the beam, k{sub wall} and k{sub pn}, for the PTB standards, which were calculated using Monte Carlo methods. (authors)

  17. Proposed specification for a primary standard of air kerma for sup 6 sup 0 Co, sup 1 sup 3 sup 7 Cs and sup 1 sup 9 sup 2 Ir gamma-ray sources

    CERN Document Server

    Angliss, R; Nutbrown, R

    2001-01-01

    The three cavity chambers, the mean response of which constitutes the primary standard of air kerma for sup 6 sup 0 Co and sup 1 sup 3 sup 7 Cs gamma-rays in the United Kingdom, have been in continuous, almost daily, use at the National Physical Laboratory (NPL) since 1956. These chambers were initially designed for use with 2 MV X-rays at therapy level air kerma rates. However since 1978 they have also been used for protection level air kerma rates, initially, with X-rays generated at 1 MV and 2 MV and more recently with sup 6 sup 0 Co and sup 1 sup 3 sup 7 Cs gamma-rays. They have been used for therapy level air kerma calibrations with sup 6 sup 0 Co gamma-rays since 1997 following the demise of the NPL 2 MV Van de Graaff generator. This report describes the proposals for a new primary standard and the methods that will be used to give a better performance than the present standard when used with air kerma rates from as high as 1 Gy min sup - sup 1 down to 10 mGy hr sup - sup 1. The design will also seek to...

  18. Key comparison BIPM.RI(I)-K7 of the air-kerma standards of the CMI, Czech Republic and the BIPM in mammography x-rays

    Science.gov (United States)

    Kessler, C.; Burns, D.; Roger, P.; Sochor, V.

    2016-01-01

    A first key comparison has been made between the air-kerma standards of the CMI, Czech Republic and the BIPM in mammography x-ray beams. The results show the standards to be in agreement at the level of the standard uncertainty for the comparison of 3.5 parts in 103. The results for an indirect comparison made at the same time are consistent with the direct results at the level of 1 part in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  19. KEY COMPARISON Comparison of the standards of air kerma of the ENEA-INMRI and the BIPM for 137Cs gamma rays

    Science.gov (United States)

    Allisy-Roberts, P. J.; Kessler, C.; Toni, M.; Bovi, M.

    2010-01-01

    A comparison of the standards of air kerma of the Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti of the Ente per le Nuove Tecnologie, l'Energia e l'Ambiente, Italy (ENEA-INMRI) and of the Bureau International des Poids et Mesures (BIPM) was carried out in 137Cs radiation in 1998. The comparison result, updated for changes in the standards in 2003 and 2009, is 0.9927 (0.0067) and demonstrates that the ENEA-INMRI and BIPM standards are in agreement within the uncertainties. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  20. Calculation of the correction factors for the primary standard of kerma in the air at the LNMRI-IRD, Rio de Janeiro, Brazil; Calculo de fatores de correcao para o padrao primario em kerma no ar do LNMRI-IRD, Rio de Janeiro, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cosme Norival Mello da, E-mail: cosme@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI)

    2009-07-01

    In order to determine the primary standardization in terms of kerma in the air, a graphite ionization chamber is used for calculation some correction factors. A program was elaborated, using the Monte Carlo Penelope for simulate the CC01-110 at the LNMRI/IRD, Rio de Janeiro, Brazil

  1. Construction of a laboratory for the implantation of primary standardization of the magnitude kerma in the air for the X-ray beams used in mammography; Construcao de um laboratorio para a implantacao da padronizacao primaria da grandeza kerma no ar para os feixes de raios X empregados em mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Cardozo, W.L.; Magalhes, L.A.A.M.F.; Peixoto, J.G.P., E-mail: wagnerlc@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI)

    2009-07-01

    Aiming to diminish the uncertainty in each phase of the metrological chain, and the uncertainty in dosimetry processed at the X-ray beam applied in the mammography, is necessary that the LNMRI/IRD to develop a reference primary standard for the absolute form to the magnitude kerma in the air

  2. Measuring instruments of the Physikalisch-Technische Bundesanstalt for realization of the units of the dosimetric quantities standard ion dose, photon-equivalent dose and air-kerma

    International Nuclear Information System (INIS)

    The realization of the units of the dosimetric quantities exposure, air-kerma and photon-equivalent dose is an important task of the Physikalisch-Technische Bundesanstalt. The report describes the measuring instruments and other technical equipment as well as the determination of the numerous corrections needed. All data and correction factors required for the realization of the units mentioned above are given in many diagrams and tables. (orig.)

  3. KEY COMPARISON: COOMET.RI(I)-K1 comparison of national measurement standards of air kerma for 60Co γ radiation

    Science.gov (United States)

    Büermann, L.; Oborin, A. V.; Dobrovosky, J.; Milevsky, V. S.; Walwyn Salas, G.; Lapenas, A.

    2009-01-01

    Results are presented of the COOMET key comparison of the national measurement standards of air kerma for 60Co γ radiation. Participants of the comparison were PTB (Germany, pilot institute), VNIIM (Russia), SMU (Slovakia), BelGIM (Belarus), CPHR (Cuba) and RMTC (Latvia). PTB, VNIIM and SMU had previously taken part in a key comparison with the Bureau International de Poids et Mesures (BIPM) and operated as link laboratories in order to evaluate the degree of equivalence of the participants' results with the key comparison reference value. These data form the basis of the results entered into the BIPM key comparison database for comparison COOMET.RI(I)-K1. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  4. Comparison between absorbed dose to water standards established by water calorimetry at the LNE-LNHB and by application of international air-kerma based protocols for kilovoltage medium energy x-rays

    International Nuclear Information System (INIS)

    Nowadays, the absorbed dose to water for kilovoltage x-ray beams is determined from standards in terms of air-kerma by application of international dosimetry protocols. New standards in terms of absorbed dose to water has just been established for these beams at the LNE-LNHB, using water calorimetry, at a depth of 2 cm in water in accordance with protocols. The aim of this study is to compare these new standards in terms of absorbed dose to water, to the dose values calculated from the application of four international protocols based on air-kerma standards (IAEA TRS-277, AAPM TG-61, IPEMB and NCS-10). The acceleration potentials of the six beams studied are between 80 and 300 kV with half-value layers between 3.01 mm of aluminum and 3.40 mm of copper. A difference between the two methods smaller than 2.1% was reported. The standard uncertainty of water calorimetry being below 0.8%, and the one associated with the values from protocols being around 2.5%, the results are in good agreement. The calibration coefficients of some ionization chambers in terms of absorbed dose to water, established by application of calorimetry and air-kerma based dosimetry protocols, were also compared. The best agreement with the calibration coefficients established by water calorimetry was found for those established with the AAPM TG-61 protocol. (paper)

  5. Evaluation of entrance surface air kerma from exposure index in computed radiography

    Science.gov (United States)

    Costa, A. M.; Pelegrino, M. S.

    2014-11-01

    The aim of this study was to establish an indirect method to calculate the values of entrance surface air kerma in patients undergoing diagnostic examinations in X-ray systems with computed radiography based on the exposure index. The entrance surface air kerma values were compared with values obtained also indirectly based on measurements of X-ray tube output. The mean±standard deviation (1σ) and third quartile for entrance surface air kerma calculated from the exposure index were 2.1±1.0 mGy and 3.0 mGy, respectively. For entrance surface air kerma based on measurements of the X-ray tube output, the mean±standard deviation (1σ) and third quartile were respectively 3.1±1.9 mGy and 5.5 mGy. The observed values of entrance surface air kerma are smaller than the reference level adopted in Brazil (10 mGy). The results obtained with both methods were similar when taking into account the estimated uncertainties in the determination of air kerma values, although the reproducibility of the determinations based on the exposure index is better.

  6. SU-E-T-552: Monte Carlo Calculation of Correction Factors for a Free-Air Ionization Chamber in Support of a National Air-Kerma Standard for Electronic Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mille, M; Bergstrom, P [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    2015-06-15

    Purpose: To use Monte Carlo radiation transport methods to calculate correction factors for a free-air ionization chamber in support of a national air-kerma standard for low-energy, miniature x-ray sources used for electronic brachytherapy (eBx). Methods: The NIST is establishing a calibration service for well-type ionization chambers used to characterize the strength of eBx sources prior to clinical use. The calibration approach involves establishing the well-chamber’s response to an eBx source whose air-kerma rate at a 50 cm distance is determined through a primary measurement performed using the Lamperti free-air ionization chamber. However, the free-air chamber measurements of charge or current can only be related to the reference air-kerma standard after applying several corrections, some of which are best determined via Monte Carlo simulation. To this end, a detailed geometric model of the Lamperti chamber was developed in the EGSnrc code based on the engineering drawings of the instrument. The egs-fac user code in EGSnrc was then used to calculate energy-dependent correction factors which account for missing or undesired ionization arising from effects such as: (1) attenuation and scatter of the x-rays in air; (2) primary electrons escaping the charge collection region; (3) lack of charged particle equilibrium; (4) atomic fluorescence and bremsstrahlung radiation. Results: Energy-dependent correction factors were calculated assuming a monoenergetic point source with the photon energy ranging from 2 keV to 60 keV in 2 keV increments. Sufficient photon histories were simulated so that the Monte Carlo statistical uncertainty of the correction factors was less than 0.01%. The correction factors for a specific eBx source will be determined by integrating these tabulated results over its measured x-ray spectrum. Conclusion: The correction factors calculated in this work are important for establishing a national standard for eBx which will help ensure that dose

  7. SU-E-T-552: Monte Carlo Calculation of Correction Factors for a Free-Air Ionization Chamber in Support of a National Air-Kerma Standard for Electronic Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To use Monte Carlo radiation transport methods to calculate correction factors for a free-air ionization chamber in support of a national air-kerma standard for low-energy, miniature x-ray sources used for electronic brachytherapy (eBx). Methods: The NIST is establishing a calibration service for well-type ionization chambers used to characterize the strength of eBx sources prior to clinical use. The calibration approach involves establishing the well-chamber’s response to an eBx source whose air-kerma rate at a 50 cm distance is determined through a primary measurement performed using the Lamperti free-air ionization chamber. However, the free-air chamber measurements of charge or current can only be related to the reference air-kerma standard after applying several corrections, some of which are best determined via Monte Carlo simulation. To this end, a detailed geometric model of the Lamperti chamber was developed in the EGSnrc code based on the engineering drawings of the instrument. The egs-fac user code in EGSnrc was then used to calculate energy-dependent correction factors which account for missing or undesired ionization arising from effects such as: (1) attenuation and scatter of the x-rays in air; (2) primary electrons escaping the charge collection region; (3) lack of charged particle equilibrium; (4) atomic fluorescence and bremsstrahlung radiation. Results: Energy-dependent correction factors were calculated assuming a monoenergetic point source with the photon energy ranging from 2 keV to 60 keV in 2 keV increments. Sufficient photon histories were simulated so that the Monte Carlo statistical uncertainty of the correction factors was less than 0.01%. The correction factors for a specific eBx source will be determined by integrating these tabulated results over its measured x-ray spectrum. Conclusion: The correction factors calculated in this work are important for establishing a national standard for eBx which will help ensure that dose

  8. The air-kerma rate constant of 192Ir.

    Science.gov (United States)

    Ninković, M M; Raiĉevìć, J J

    1993-01-01

    The air-kerma rate constant gamma delta (and its precursors), as one of the basic radiation characteristics of 192Ir, was determined by many authors. Analysis of accessible data on this quantity led us to the conclusion that published data strongly disagree. That is the reason we calculated this quantity on the basis of our and many other authors' gamma-ray spectral data and the latest data for mass energy-transfer coefficients for air. In this way, a value was obtained for gamma delta of 30.0 +/- 0.9 a Gy m2 s-1 Bq-1 for an unshielded 192Ir source and 27.8 +/- 0.9 a Gy m2s -1Bq-1 for a standard packaged radioactive source taking into account attenuation of gamma rays in the platinum source wall. PMID:8416220

  9. Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the ENEA-INMRI, Italy and the BIPM in low-energy x-rays

    International Nuclear Information System (INIS)

    A key comparison has been made between the air-kerma standards of the ENEA-INMRI, Italy and the BIPM in the low-energy x-ray range. The results show the standards to be in agreement at the level of the standard uncertainty for the comparison of 1.9 parts in 103. No significant trend with radiation quality is observed. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)

  10. Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the LNE-LNHB, France and the BIPM in low-energy x-rays

    International Nuclear Information System (INIS)

    A key comparison has been made between the air-kerma standards of the LNE-LNHB, France and the BIPM in the low-energy x-ray range. The results show the standards to be in agreement at the level of the standard uncertainty of the comparison of 1.6 parts in 103, with no evidence of a trend in the results at different radiation qualities. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)

  11. Kerma determination in air on mamma by thermoluminescence; Determinacion de Kerma en aire en mama por termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Palacios P, L. L.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, 11500 Mexico D. F. (Mexico)], e-mail: lpalaciop@ipn.mx

    2009-10-15

    In this work the experimental results of the entrance exposition are shown and Kerma in air [mGy] in mamma obtained by irradiation of accreditation phantom of American College of Radiology (ACR). The irradiations were realized in a conventional mammography equipment of Hospital Juarez in Mexico; the technique used during the irradiations was of automatic exposition; the thickness for the phantom ACR obtained by the technique were of 4.2 and 4.5 cm; the kilo voltage pick was of 24 kV{sub p}, the time and the milli amperage per second variable. The measuring of Kerma in air was obtained with thermoluminescent dosemeters of solid state, of nano particles of zirconium dioxide prepared by the precipitation method. The dosemeters were homogenized previously in low energies of X-rays that are those used for mammography. The thermoluminescent dosemeters of ZrO{sub 2} were calibrated by means of an ionization chamber for different expositions. The calibration curve is reported for the exposition and Kerma in air against thermoluminescent intensity obtained by reading of thermoluminescent dosemeters of ZrO{sub 2}, as well as the technique employee for the Kerma determination in air and entrance exposition in mamma. (Author)

  12. Study of the spatial variation of the air kerma backscatter factor on the standard ISO phantom, with a Co-60 irradiator

    International Nuclear Information System (INIS)

    Personal dosimeters should be calibrated on the surface of the ISO water phantom. For this purpose dose values should present a uniform distribution over the calibration area of diameter dF. To determine the boundary of the uniform dose area, two complementary approaches are purposed: the experimental and the numerical simulation. This article presents the results of Monte Carlo calculations and experimental determinations of the spatial variation of the air kerma backscatter factor on the ISO water phantom surface performed for the Co-60 gamma radiation quality. The experimental B values on the center of the phantom surface was 1.04 and dF was 30 cm. However, the experimental determination of the variation of B along the axis of the phantom is a very consuming time process and is very sensitive to the positioning of the ionisation chamber. The methodology advanced in this work allows the knowledge of values of B along the apothem and diagonal axis using only one experimental value the B value on the center of the phantom and taking into account the relative variation of B from the simulation results. (author)

  13. Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the CMI, Czech Republic and the BIPM in low-energy x-rays

    Science.gov (United States)

    Burns, D. T.; Kessler, C.; Sochor, V.

    2016-01-01

    A key comparison has been made between the air-kerma standards of the CMI, Czech Republic and the BIPM in the low-energy x-ray range. The results show the standards to be in agreement at around the level of the standard uncertainty of the comparison of 3.5 parts in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  14. Comparison of the air-kerma standards of the PTB and the BIPM in the medium-energy X-ray range

    International Nuclear Information System (INIS)

    An indirect comparison has been made between the air erma standards of the PTB and the BIPM in the medium-energy x-ray range. The results show the standards to be in general agreement at the level of the stated standard uncertainty, although the result for the 100 kV radiation quality differs significantly from that for the other qualities. (authors)

  15. Comparison of the air-kerma standards of the VNIIM and the BIPM in the low-energy X-ray range

    International Nuclear Information System (INIS)

    An indirect comparison has been made between the air erma standards of the VNIIM and the BIPM in the low-energy x-ray range. The results show the standards to be in agreement at the level of one to two standard uncertainties. The trend in the results at different radiation qualities is explained in terms of the photon-scatter correction applied to the VNIIM standard. (authors)

  16. Comparison of the air-kerma standards of the ENEA-INMRI and the BIPM in the medium-energy X-ray range

    International Nuclear Information System (INIS)

    An indirect comparison has been made between the air erma standards of the ENEA-INMRI and the BIPM in the medium-energy x-ray range. The results show the standards to be in general agreement within the stated uncertainty, although there is evidence of a trend in the results at different radiation qualities. (authors)

  17. Key Comparison APMP.RI(I)-K2 of air kerma standards for the CCRI reference radiation qualities for low-energy x-rays, including a supplementary comparison for the ISO 4037 narrow spectrum series

    International Nuclear Information System (INIS)

    An indirect comparison was performed between nine national standards for air kerma for the CCRI radiation qualities from 10 kV to 50 kV (APMP.RI(I)-K2) and for the ISO 4037 narrow spectrum series (15 kV and 40 kV). Among the nine institutes that participated in the comparison, seven institutes were APMP member laboratories. Three commercially available thin window parallel plate ionization chambers were used as transfer instruments and circulated among the participants. The pilot laboratory, the NMIJ/AIST, served also as the link to the corresponding BIPM.RI(I)-K2 comparison. The results show general agreement within the combined uncertainties, although certain results for Nuclear Malaysia, the BARC and the OAP show larger differences. (authors)

  18. Evaluation of entrance surface air kerma in pediatric chest radiography

    International Nuclear Information System (INIS)

    The objective of this study was to evaluate the entrance surface air kerma in pediatric chest radiography. An evaluation of 301 radiographical examinations in anterior–posterior (AP) and posterior–anterior (PA) (166 examinations) and lateral (LAT) (135 examinations) projections was performed. The analyses were performed on patients grouped by age; the groups included ages 0–1 y, 1–5 y, 5–10 y, and 10–15 y. The entrance surface air kerma was determined with DoseCal software (Radiological Protection Center of Saint George's Hospital, London) and thermoluminescent dosimeters. Two different exposure techniques were compared. The doses received by patients who had undergone LAT examinations were 40% higher, on average, those in AP/PA examinations because of the difference in tube voltage. A large high-dose “tail” was observed for children up to 5 y old. An increase in tube potential and corresponding decrease in current lead to a significant dose reduction. The difference between the average dose values for different age ranges was not practically observed, implying that the exposure techniques are still not optimal. Exposure doses received using the higher tube voltage and lower current-time product correspond to the international diagnostic reference levels. - Highlights: • The entrance surface air kerma of chest X-ray examinations in pediatric patients was estimated. • The data were analyzed for patients aged up to 15 y, stratified by age. • The doses of LAT examinations were 40% higher than of AP/PA because of kV used. • An increase in kV with a decrease in mAs leads to significant dose reduction

  19. Air kerma rates measurement in an interventional cardiology suite

    International Nuclear Information System (INIS)

    In Interventional Cardiology (IC), the assessment of the radiation that the physicians are exposed to is extremely important because the irradiation is not uniform and the received doses are substantially high. During the procedure, the radiation control is complex and there are several reasons for the high exposure levels. It is necessary to perform dosimetric assessments in different parts of the physicians' body and in different specific points of the examination room. By analyzing this information it is possible to determine the probable causes and to provide recommendations, aiming at optimizing the radiological protection. This work had the following objectives: to assess the exposition levels at representative points of critical anatomical regions of the physicians' body who perform IC examinations; to provide means to implement personal monitoring procedures; and to make them aware of the radiation risks. Measurements of air kerma rates were performed in 45 points around the examination table, along the room. Such measurements were made in the conditions frequently used in coronary angiography and coronary angioplasties procedures: adult patient phantom; RAO, LAO and AP incidences; fluoro and digital modes; 13cm and 17cm magnification modes; frequencies of 30f/s (fluoro) and 15 f/s (digital); typical field size used during examinations. Data were obtained at the lenses, chest, hands, gonads and knees levels. For AP incidence, the lowest contributions for scattered radiation and a more homogeneous distribution of radiation were observed. The highest air kerma rates were obtained during digital acquisition mode and for LAO incidence on interventional radiologists, anaesthesists and nurses. The most critical anatomical regions were the knees and gonads. Air kerma rates of about 7,8mGy/h were registered in some places. At physicians' hands position, rates of about 5mGy/h were reached. In several points and levels measured (workload ∼ 6 examinations/day), this

  20. Comparison of two different methods to determine the air kerma calibration factor (NK) for 192Ir

    International Nuclear Information System (INIS)

    In brachytherapy, encapsulated radioactive Low Dose Rate (LDR) and High Dose Rate (HDR) sources are used to deliver a dose to tissue near the source. One of the nuclides used in LDR as well as in HDR brachytherapy sources is 192Ir. In document IAEA-TECDOC-1079, Calibration of Brachytherapy Sources, recommendations on standardized procedures for the calibration of brachytherapy sources at SSDLs and hospitals are given. One of these recommendations is the use of an ionisation chamber with an air-kerma calibration factor for 192lr sources. The problem to derive a calibration factor for 192Ir is that the most important part of the spectrum of an 192lr brachytherapy source falls in an energy gap between the standards for x-rays and the standards for gamma-rays established at primary laboratories. It is therefore unavoidable to obtain the air kerma calibration for the ionisation chamber using an indirect method. The method recommended by IAEA for the determination of the air-kerma calibration factors is based on a technique developed by Goetsch et al. In the Netherlands a different method is recommended. This method is based on a weighting procedure of the 192Ir energy spectrum over the response curve of an ionisation chamber and differs with the procedure recommended by IAEA for a NE2561 ionisation chamber by about 0.9 %

  1. Comparison of air-kerma strength determinations for HDR 192Ir sources

    International Nuclear Information System (INIS)

    Purpose: To perform a comparison of the interim air-kerma strength standard for high dose rate (HDR) 192Ir brachytherapy sources maintained by University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) with measurements of the various source models using modified techniques from the literature. The current interim standard was established by Goetsch et al. in 1991 and has remained unchanged to date. Methods: The improved, laser-aligned seven-distance apparatus of University of Wisconsin Medical Radiation Research Center (UWMRRC) was used to perform air-kerma strength measurements of five different HDR 192Ir source models. The results of these measurements were compared with those from well chambers traceable to the original standard. Alternative methodologies for interpolating the 192Ir air-kerma calibration coefficient from the NIST air-kerma standards at 137Cs and 250 kVp x rays (M250) were investigated and intercompared. As part of the interpolation method comparison, the Monte Carlo code EGSnrc was used to calculate updated values of Awall for the Exradin A3 chamber used for air-kerma strength measurements. The effects of air attenuation and scatter, room scatter, as well as the solution method were investigated in detail. Results: The average measurements when using the inverse NK interpolation method for the Classic Nucletron, Nucletron microSelectron, VariSource VS2000, GammaMed Plus, and Flexisource were found to be 0.47%, -0.10%, -1.13%, -0.20%, and 0.89% different than the existing standard, respectively. A further investigation of the differences observed between the sources was performed using MCNP5 Monte Carlo simulations of each source model inside a full model of an HDR 1000 Plus well chamber. Conclusions: Although the differences between the source models were found to be statistically significant, the equally weighted average difference between the seven-distance measurements and the well chambers was 0.01%, confirming that it is

  2. Rate air Kerma entrance skin of patients undergoing hemodynamic procedures in the State of Santa Catarina, Brazil

    International Nuclear Information System (INIS)

    This paper presents the results of the measured values of the skin entrance Air Kerma Rate in patients submitted to hemodynamic procedures, in the State of Santa Catarina, using as limit values set by the International Basic Safety Standards Guide, published by the International Atomic Energy Agency (IAEA ), and comparing them to the limits established by the Ordinance No. 453/1998. Tests were performed to measure the rate of Kerma skin entrance in 13 hemodynamic equipment in 10 hospitals in the state of Santa Catarina, between January 2011 and December 2012, in hemodynamic operated through fluoroscopy mode. Among the evaluated equipment, 77% disagree with the limits established in the International Basic Safety Standards, however, if compared the values of the Air Kerma rate obtained with the limit established by Ordinance No. 453, 100% of the devices are approved. The results obtained in this paper suggest the need for revision of the Ordinance No. 453/1998, by the regulatory agencies. (author)

  3. A conversion method of air kerma from the primary, scatter, and leakage radiations to effective dose for calculating x-ray shielding barriers in mammography

    International Nuclear Information System (INIS)

    In this study, a new approach has been introduced for derivation of the effective dose from air kerma to calculate shielding requirements in mammography facilities. This new approach has been used to compute the conversion coefficients relating air kerma to the effective dose for the mammography reference beam series of the Netherlands Metrology Institute Van Swinden Laboratorium, National Institute of Standards and Technology, and International Atomic Energy Agency laboratories. The results show that, in all cases, the effective dose in mammography energy range is less than 25% of the incident air kerma for the primary and the scatter radiations and does not exceed 75% for the leakage radiation

  4. New primary ionization chambers at LNE-LNHB for determining the air kerma in a cobalt-60 beam

    International Nuclear Information System (INIS)

    For radioprotection, the reference quantity is air kerma. For an cobalt-60 beam, the reference dosimeter is a cavity ionization chamber whose volume is measured. The new LNE-LNHB reference is based on six different chambers instead of one as was done previously. Although every new ionization chamber was treated as much as possible in the same way (manufacturing, measurements of volumes, wall effect calculations, current corrections), a maximum discrepancy of 0.2% was observed between the final measurement results from each chamber. The final value of the air kerma rate in reference conditions was determined as the mean value of the measurement results from all six chambers. Among the different factors whose determination is necessary to calculate the air kerma rate, some are considered independent of or common to all the graphite-walled ionization chambers (for example, mean energy expended by an electron to produce an ion pair in dry air), while others vary for each chamber (for example, air cavity ionic collection volume). Considering that the uncertainties of the individual ionization chamber measurement results seem slightly underestimated, the uncertainty on the mean of the six chamber-dependent factors products was taken equal to the standard deviation of the sample composed of the six chamber-dependent factors products (0.08%). Compared to the previous standard, the air kerma rate of the 60Co photon beam would then increase by 0.09% and the air kerma rate uncertainty would drop from 0.38% to 0.31%. This article describes the procedure used to establish the primary standard in terms of absorbed dose to tissue of LNE-LNHB. (authors)

  5. X-rays spectrum and air Kerma during a mammography study; Espectro de los rayos X y Kerma en aire durante un estudio mamografico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Av. Heroes de Nacozari Sur 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico); Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)], e-mail: fermineutron@yahoo.com

    2009-10-15

    In this calculation series was modeled the source of electrons, the target and the filter. Using thermoluminescent dosemeters of ZrO{sub 2}+PTFE the air Kerma was measured in five points located on a phantom made with acrylic and water when it was exposed to a X-rays beam produced by electrons of 24 KeV and 10 m A of current that produces a mammography. The air Kerma values at the entrance surface of the phantom were compared with values calculated by Monte Carlo methods. The air Kerma values measured indicate that approximately the five points receive the same air Kerma, what means that the beam is homogeneous, of the Monte Carlo calculations we find that the center receives a greater dose what implies that the beam is not uniform, the explanation of this fact is attributed to was used a simple model in the calculations, nevertheless, the air Kerma average measured at the entrance surface of the phantom was of 0.96 +{sub -} 0.03 m G, while the other obtained by the calculations was of 0.96 +{sub -} 0.06 mGy, to compare both do not exist significant differences. (author)

  6. Measurement of air kerma rate for Cs-137 using different ionization chambers

    International Nuclear Information System (INIS)

    Due to the importance of radiation doses in medical field quality assurance should be established in order to maintain a reasonable balance between the purpose of application and exposure. This study had been carried out to achieve quality control for protection based on air kerma rate. Measurements were performed by using Cs-137 for the comparison of two working ionization chambers in secondary standard dosimetry laboratory of Sudan. Spherical ionization chamber L S-01 1000 cc S/N 912 and Farmer ionization chamber 2675 A 600 cc S/N 0511, respectively. The results obtained from this study have been represented as mean and their standard deviations shown in most cases remains at 5% uncertainly. Comparison between kinetic energy released per unit mass in air rate (air kerma rate) were obtained by using spherical ionization chamber L S-01 1000 cc S/N 912 and results have been determined using inverse square law. The differences have been represented as means and standard deviations with significant P-value less than 0.05. Spherical ionization chamber gives accurate, reproducible results with acceptable uncertainty which is more suitable for calibration of radiation detectors.(Author)

  7. Evaluation and test of 192Ir air kerma strength for afterloading systems

    International Nuclear Information System (INIS)

    Objective: To study the method of measuring air kerma strength of afterloading units with 192Ir source by using well type ionization chamber. Methods: The air kerma strength of 30 afterloading units with 192Ir source was measured using 2000A electrometer and 1000 plus well type ionization chamber, and apparent activity of the source was calculated with the air kerma strength and apparent activity conversion factor. The measured activity of the source was compared with the original value of the source provided by the manufacturer, and the relevant deviation should be within ±5%. Results: The air kerma strength of afterloading units with 192Ir sources was tested. The relevant deviation of the measured activity and the original value was within -0.1%-4.4%. Conclusions: The measurement method with a well type ionization chamber is convenient and highly accurate which can be used for the test of quality control in hospitals. (authors)

  8. Image quality and volume computed tomography air kerma index (Cvol) evaluation in Recife

    International Nuclear Information System (INIS)

    The Computed Tomography (CT) is an important diagnostic imaging method, widely used. However, in spite of all the advantages and technologic advances within the CT scanners, the tomographic procedures result in high absorbed doses to patients. The main objective of this work was to perform a dosimetric study of CT scanners located at Recife and to evaluate the image quality on CT examinations in these equipment. The volume CT air kerma index (CVOL) and air kerma length product (PKL,CT) were estimated. These values were calculated using normalized weighted air kerma indexes in CT standard dosimetry phantoms (nCW), supplied by ImPACT group for several CT scanners, and the scan parameters of routine head, routine chest and hi-resolution chest CT exams performed at 20 institutions. The irradiation parameters of 15 adult patients for each CT procedure were registered at six participating centres, at which the phantom from the American College of Radiology (ACR) CT accreditation protocol was used for the image quality measurements. For routine head exams, the CVOL values varied between 12 and 58 mGy (at the posterior fossa) and 15 to 58 mGy (at the cerebrum) and the PKL,CT, from 150 to 750 mGy·cm. The CVOL values for routine chest procedures varied from 3 to 26 mGy and the PKL,CT, between 120 and 460 mGy·cm. In relation to Hi-resolution chest exams, CVOL values were from 1.0 to 2.7 mGy and the PKL,CT values varied between 24 and 67 mGy·cm. The image quality evaluations results showed that almost all scanners presented at least one inadequacy. One of the equipment presented faults at 70% of the tests. With regard to the image noise, only two scanners presented acceptable results. From these results, it is possible to conclude that the volume CT air kerma index values are lower than the European reference levels. However, the image quality of these CT scanners does not attend the ACR requirements, suggesting the need to implement quality assurance programs at the

  9. Reference air kerma and kerma-area product as estimators of peak skin dose for fluoroscopically guided interventions

    International Nuclear Information System (INIS)

    Purpose: To determine more accurate regression formulas for estimating peak skin dose (PSD) from reference air kerma (RAK) or kerma-area product (KAP). Methods: After grouping of the data from 21 procedures into 13 clinically similar groups, assessments were made of optimal clustering using the Bayesian information criterion to obtain the optimal linear regressions of (log-transformed) PSD vs RAK, PSD vs KAP, and PSD vs RAK and KAP. Results: Three clusters of clinical groups were optimal in regression of PSD vs RAK, seven clusters of clinical groups were optimal in regression of PSD vs KAP, and six clusters of clinical groups were optimal in regression of PSD vs RAK and KAP. Prediction of PSD using both RAK and KAP is significantly better than prediction of PSD with either RAK or KAP alone. The regression of PSD vs RAK provided better predictions of PSD than the regression of PSD vs KAP. The partial-pooling (clustered) method yields smaller mean squared errors compared with the complete-pooling method.Conclusion: PSD distributions for interventional radiology procedures are log-normal. Estimates of PSD derived from RAK and KAP jointly are most accurate, followed closely by estimates derived from RAK alone. Estimates of PSD derived from KAP alone are the least accurate. Using a stochastic search approach, it is possible to cluster together certain dissimilar types of procedures to minimize the total error sum of squares.

  10. X-rays spectrum and air Kerma during a mammography study

    International Nuclear Information System (INIS)

    In this calculation series was modeled the source of electrons, the target and the filter. Using thermoluminescent dosemeters of ZrO2+PTFE the air Kerma was measured in five points located on a phantom made with acrylic and water when it was exposed to a X-rays beam produced by electrons of 24 KeV and 10 m A of current that produces a mammography. The air Kerma values at the entrance surface of the phantom were compared with values calculated by Monte Carlo methods. The air Kerma values measured indicate that approximately the five points receive the same air Kerma, what means that the beam is homogeneous, of the Monte Carlo calculations we find that the center receives a greater dose what implies that the beam is not uniform, the explanation of this fact is attributed to was used a simple model in the calculations, nevertheless, the air Kerma average measured at the entrance surface of the phantom was of 0.96 +- 0.03 m G, while the other obtained by the calculations was of 0.96 +- 0.06 mGy, to compare both do not exist significant differences. (author)

  11. Uncertainty evaluation of the kerma in the air, related to the active volume in the ionization chamber of concentric cylinders, by Monte Carlo simulation; Avaliacao de incerteza no kerma no ar, em relacao ao volume ativo da camara de ionizacao de cilindros concentricos, por simulacao de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Lo Bianco, A.S.; Oliveira, H.P.S.; Peixoto, J.G.P., E-mail: abianco@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI)

    2009-07-01

    To implant the primary standard of the magnitude kerma in the air for X-ray between 10 - 50 keV, the National Metrology Laboratory of Ionizing Radiations (LNMRI) must evaluate all the uncertainties of measurement related with Victtoren chamber. So, it was evaluated the uncertainty of the kerma in the air consequent of the inaccuracy in the active volume of the chamber using the calculation of Monte Carlo as a tool through the Penelope software

  12. X-Rays spectrum and air kerma during a mammography study;Espectro de los rayos X y kerma en aire durante un estudio mamografico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Direccion General de Innovacion y Tecnologia de Informacion, Av. Heroes de Nacozari Sur No. 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico); Hernandez V, R.; Chacon R, A.; Vega C, H. R., E-mail: ramirezgonzalezjaime@yahoo.com.m [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2009-10-15

    The X-rays spectrum produced in a mammography has been calculated by means of Monte Carlo methods. In this calculation series it is modeled the electrons source, the target and the filter. The spectra were calculated for an energy of the electrons of 28 keV and for targets of W, Mo and Rh. The calculations extended to analyze the effect that produces the filters inclusion in the spectra; the spectra of W-A1, Rh-Rh, Mo-Mo, Mo-Rh and Mo-Be were calculated this way. Using thermoluminescent dosemeters of ZrO{sub 2}+PTFE the air kerma was measured in five points located on a phantom made with acrylic and water when it is was exposed to a X-rays beam produced by electrons of 24 keV and 10 m A of current that it produces a mammography. The values of the air kerma on the entrance surface of the phantom were compared with the calculated values by means of Monte Carlo methods. The calculated spectra present a continuous component and another discreet and its form is similar to the reported spectra in the literature. The filters inclusion allows the elimination of the low energy photons that do not have utility in the obtaining of the mammography image and only they contribute to deposit a dose in the mamma. The values of the measured air kerma indicate that the five points receive the same air kerma approximately, what means that the beam is homogeneous, of the Monte Carlo calculations we find that the center receives a bigger dose which implies that the beam is not uniform, the explanation on this fact it is attributed to that a simple model was used in the calculations, nevertheless, the average of the air kerma measured on the entrance surface of the phantom was of 0.96 +- 0.03 m G, while the obtained by means of the calculations was of 0.96 +- 0.06 mGy, when comparing both significant differences do not exist. (Author)

  13. Air kerma to Hp(3) conversion coefficients for a new cylinder phantom for photon reference radiation qualities

    International Nuclear Information System (INIS)

    The International Organization for Standardization (ISO) has issued a standard series on photon reference radiation qualities (ISO 4037). In this series, no conversion coefficients are contained for the quantity personal dose equivalent at a 3 mm depth, Hp(3). In the past, for this quantity, a slab phantom was recommended as a calibration phantom; however, a cylinder phantom much better approximates the shape of a human head than a slab phantom. Therefore, in this work, the conversion coefficients from air kerma to Hp(3) for the cylinder phantom are supplied for X- and gamma radiation qualities defined in ISO 4037. (authors)

  14. Air kerma to Hp(3) conversion coefficients for a new cylinder phantom for photon reference radiation qualities.

    Science.gov (United States)

    Behrens, R

    2012-09-01

    The International Organization for Standardization (ISO) has issued a standard series on photon reference radiation qualities (ISO 4037). In this series, no conversion coefficients are contained for the quantity personal dose equivalent at a 3 mm depth, H(p)(3). In the past, for this quantity, a slab phantom was recommended as a calibration phantom; however, a cylinder phantom much better approximates the shape of a human head than a slab phantom. Therefore, in this work, the conversion coefficients from air kerma to H(p)(3) for the cylinder phantom are supplied for X- and gamma radiation qualities defined in ISO 4037. PMID:22434922

  15. A comparison of measured and calculated values of air kerma rates from 137Cs in soil

    Directory of Open Access Journals (Sweden)

    V. P. Ramzaev

    2016-01-01

    Full Text Available In 2010, a study was conducted to determine the air gamma dose rate from 137Cs deposited in soil. The gamma dose rate measurements and soil sampling were performed at 30 reference plots from the south-west districts of the Bryansk region (Russia that had been heavily contaminated as a result of the Chernobyl accident. The 137Cs inventory in the top 20 cm of soil ranged from 260 kBq m–2 to 2800 kBq m–2. Vertical distributions of 137Cs in soil cores (6 samples per a plot were determined after their sectioning into ten horizontal layers of 2 cm thickness. The vertical distributions of 137Cs in soil were employed to calculate air kerma rates, K, using two independent methods proposed by Saito and Jacob [Radiat. Prot. Dosimetry, 1995, Vol. 58, P. 29–45] and Golikov et al. [Contaminated Forests– Recent Developments in Risk Identification and Future Perspective. Kluwer Academic Publishers, 1999. – P. 333–341]. A very good coincidence between the methods was observed (Spearman’s rank coefficient of correlation = 0.952; P<0.01; on average, a difference between the kerma rates calculated with two methods did not exceed 3%. The calculated air kerma rates agreed with the measured dose rates in air very well (Spearman’s coefficient of correlation = 0.952; P<0.01. For large grassland plots (n=19, the measured dose rates were on average 6% less than the calculated kerma rates. The tested methods for calculating the air dose rate from 137Cs in soil can be recommended for practical studies in radiology and radioecology. 

  16. Product estimate of air kerma-area and the air kerma in the input surface of the skin of pediatric patients undergoing chest X-ray

    International Nuclear Information System (INIS)

    The aim of this paper is to evaluate the entrance air kerma (Ka,e) and the product air kerma-area (Pka) for chest examinations performed with pediatric patients in a large public hospital of Recife. For this study 89 examinations of patient with ages from zero to 10 years old were evaluated. The results showed that the mean Ka,e values, for patients of 0-1 years old, 1-5 years old and 5-10 years old, were, respectively, 100 mGy, 120 mGy and 100 mGy. The Pka values for newborn patients range from 11,9 to 58,4 mGy.cm2, for patients with 1 to 5 years old range from 17 to 192 mGy.cm2, and from 30,4 to 136,2 mGy.cm2 for patients with ages from 5 to 10 years old. The differences in the Pka values are due the different dimensions of the radiation field. For the results its possible to conclude that the Pka values are high, in special for patients with ages from 1 to 5 years old, indicating that the collimation of the radiation field is not adequate. (author)

  17. Portable meter study of ionizing radiation Teletector in high rates of air kerma

    International Nuclear Information System (INIS)

    A set of portable meters of ionizing radiation high rates of air kerma (teletectors) commonly used in emergencies in Brazil and sent to the Calibration Laboratory of IPEN were under several tests and analyst is parameters for the detectors behavior were established. Applied tests were: energy dependence and primarily overload with the new irradiation system. Thus it was possible to determine the most common characteristic found in these equipment (quality control programs) and new calibration criteria were established following international recommendations. (author)

  18. Air kerma distribution in an irradiation facility - Comparison of Monte Carlo simulations with physical dosimetry

    International Nuclear Information System (INIS)

    In order to evaluate the effectiveness of Monte Carlo methods applied to shielding calculations, an air kerma rate evaluation was performed in different locations of a 60Co gamma irradiator, operated for industrial and research purposes in a state laboratory at Nuclear and Technological Inst. near Lisbon. The MCNPX code was used to perform the radiation transport simulation along the facility. Variance reduction techniques were used by implementing, among others, the weight window generator to account for the air kerma rate in the access maze leading to the facility's irradiation chamber. Analog Monte Carlo simulations were also performed to test the correct implementation of the non analog techniques used and to evaluate the computational efficiency gain. The validation of the computational results is discussed by comparison with physical dosimetry measurements using ionization chambers. The results obtained show a good agreement between the simulations and the measurements for the positions in and the exit of the irradiation room. Discrepancies were found for the positions where the air kerma rate is lower resulting from the deeper penetration of radiation across the shields and scattering through the maze walls. Further insight must be gained to improve the results at these positions. (authors)

  19. X-Rays spectrum and air kerma during a mammography study

    International Nuclear Information System (INIS)

    The X-rays spectrum produced in a mammography has been calculated by means of Monte Carlo methods. In this calculation series it is modeled the electrons source, the target and the filter. The spectra were calculated for an energy of the electrons of 28 keV and for targets of W, Mo and Rh. The calculations extended to analyze the effect that produces the filters inclusion in the spectra; the spectra of W-A1, Rh-Rh, Mo-Mo, Mo-Rh and Mo-Be were calculated this way. Using thermoluminescent dosemeters of ZrO2+PTFE the air kerma was measured in five points located on a phantom made with acrylic and water when it is was exposed to a X-rays beam produced by electrons of 24 keV and 10 m A of current that it produces a mammography. The values of the air kerma on the entrance surface of the phantom were compared with the calculated values by means of Monte Carlo methods. The calculated spectra present a continuous component and another discreet and its form is similar to the reported spectra in the literature. The filters inclusion allows the elimination of the low energy photons that do not have utility in the obtaining of the mammography image and only they contribute to deposit a dose in the mamma. The values of the measured air kerma indicate that the five points receive the same air kerma approximately, what means that the beam is homogeneous, of the Monte Carlo calculations we find that the center receives a bigger dose which implies that the beam is not uniform, the explanation on this fact it is attributed to that a simple model was used in the calculations, nevertheless, the average of the air kerma measured on the entrance surface of the phantom was of 0.96 ± 0.03 m G, while the obtained by means of the calculations was of 0.96 ± 0.06 mGy, when comparing both significant differences do not exist. (Author)

  20. Calculated neutron air kerma strength conversion factors for a generically encapsulated Cf-252 brachytherapy source

    CERN Document Server

    Rivard, M J; D'Errico, F; Tsai, J S; Ulin, K; Engler, M J

    2002-01-01

    The sup 2 sup 5 sup 2 Cf neutron air kerma strength conversion factor (S sub K sub N /m sub C sub f) is a parameter needed to convert the radionuclide mass (mu g) provided by Oak Ridge National Laboratory into neutron air kerma strength required by modern clinical brachytherapy dosimetry formalisms indicated by Task Group No. 43 of the American Association of Physicists in Medicine (AAPM). The impact of currently used or proposed encapsulating materials for sup 2 sup 5 sup 2 Cf brachytherapy sources (Pt/Ir-10%, 316L stainless steel, nitinol, and Zircaloy-2) on S sub K sub N /m sub C sub f was calculated and results were fit to linear equations. Only for substantial encapsulation thicknesses, did S sub K sub N /m sub C sub f decrease, while the impact of source encapsulation composition is increasingly negligible as Z increases. These findings are explained on the basis of the non-relativistic kinematics governing the majority of sup 2 sup 5 sup 2 Cf neutron interactions. Neutron kerma and energy spectra resul...

  1. The performance of the INER improved free-air ionization chamber in the comparison of air kerma calibration coefficients for medium-energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.-H. E-mail: jhlee@iner.gov.tw; Kotler, L.H.; Bueermann, Ludwig; Hwang, W.-S.; Chiu, J.-H.; Wang, C.-F

    2005-01-01

    This paper describes modifications to an original design, correction factors and uncertainty evaluations for an improved free-air ionization chamber constructed at the Institute of Nuclear Energy Research (INER, Taiwan). In addition, a comparison of secondary standard air kerma calibration coefficients for 100-250 kV medium-energy X-rays was performed to verify the experimental accuracy and measurement consistency of the improved chamber. The comparison results showed a satisfactory agreement in the measurements which were within the combined expanded uncertainties (k=2)

  2. The performance of the INER improved free-air ionization chamber in the comparison of air kerma calibration coefficients for medium-energy X-rays

    International Nuclear Information System (INIS)

    This paper describes modifications to an original design, correction factors and uncertainty evaluations for an improved free-air ionization chamber constructed at the Institute of Nuclear Energy Research (INER, Taiwan). In addition, a comparison of secondary standard air kerma calibration coefficients for 100-250 kV medium-energy X-rays was performed to verify the experimental accuracy and measurement consistency of the improved chamber. The comparison results showed a satisfactory agreement in the measurements which were within the combined expanded uncertainties (k=2)

  3. Integration of kerma-area product and cumulative air kerma determination into a skin dose tracking system for fluoroscopic imaging procedures

    Science.gov (United States)

    Vijayan, Sarath; Shankar, Alok; Rudin, Stephen; Bednarek, Daniel R.

    2016-03-01

    The skin dose tracking system (DTS) that we developed provides a color-coded mapping of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures in real time. The DTS has now been modified to also calculate the kerma area product (KAP) and cumulative air kerma (CAK) for fluoroscopic interventions using data obtained in real-time from the digital bus on a Toshiba Infinix system. KAP is the integral of air kerma over the beam area and is typically measured with a large-area transmission ionization chamber incorporated into the collimator assembly. In this software, KAP is automatically determined for each x-ray pulse as the product of the air kerma/ mAs from a calibration file for the given kVp and beam filtration times the mAs per pulse times the length and width of the beam times a field nonuniformity correction factor. Field nonuniformity is primarily the result of the heel effect and the correction factor was determined from the beam profile measured using radio-chromic film. Dividing the KAP by the beam area at the interventional reference point provides the area averaged CAK. The KAP and CAK per x-ray pulse are summed after each pulse to obtain the total procedure values in real-time. The calculated KAP and CAK were compared to the values displayed by the fluoroscopy machine with excellent agreement. The DTS now is able to automatically calculate both KAP and CAK without the need for measurement by an add-on transmission ionization chamber.

  4. Measurement of conversion coefficients between air Kerma and personal dose equivalent and backscatter factors for diagnostic X-ray beams

    International Nuclear Information System (INIS)

    Two sets of quantities are import in radiological protection: the protection and operational quantities. Both sets can be related to basic physical quantities such as kerma through conversion coefficients. For diagnostic x-ray beams the conversion coefficients and backscatter factors have not been determined yet, those parameters are need for calibrating dosimeters that will be used to determine the personal dose equivalent or the entrance skin dose. Conversion coefficients between air kerma and personal dose equivalent and backscatter factors were experimentally determined for the diagnostic x-ray qualities RQR and RQA recommended by the International Electrotechnical Commission (IEC). The air kerma in the phantom and the mean energy of the spectrum were measured for such purpose. Harshaw LiF-100H thermoluminescent dosemeters (TLD) were used for measurements after being calibrated against an 180 cm3 Radcal Corporation ionization chamber traceable to a reference laboratory. A 300 mm x 300 mm x 150 mm polymethylmethacrylate (PMMA) slab phantom was used for deep-dose measurements. Tl dosemeters were placed in the central axis of the x-ray beam at 5, 10, 15, 25 and 35 mm depth in the phantom upstream the beam direction Another required parameter for determining the conversion coefficients from was the mean energy of the x-ray spectrum. The spectroscopy of x-ray beams was done with a CdTe semiconductor detector that was calibrated with 133 Ba, 241 Am and 57 Co radiation sources. Measurements of the x-ray spectra were carried out for all RQR and RQA IEC qualities. Corrections due to the detector intrinsic efficiency, total energy absorption, escape fraction of the characteristic x-rays, Compton effect and attenuation in the detector were done aiming an the accurate determination of the mean energy. Measured x-ray spectra were corrected with the stripping method by using these response functions. The typical combined standard uncertainties of conversion coefficients and

  5. Sensitivity/uncertainty analysis for free-in-air tissue kerma due to initial radiation at Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Uncertainty estimates and cross correlations by range/survivor have been calculated for the Hiroshima and Nagasaki free-in-air (FIA) tissue kerma obtained from two-dimensional air/ground transport calculations. The uncertainties due to modeling parameter and basic nuclear transport data uncertainties were calculated for 700-, 1000-, and 1500-m ground ranges. Only the FIA tissue kerma due to initial radiation was treated in the analysis; the uncertainties associated with terrain and building shielding and phantom attenuation were not considered in this study. Uncertainties of --20% were obtained for the prompt neutron and secondary gamma kerma and 30% for the prompt gamma kerma at both cities. The uncertainties on the total prompt kerma at Hiroshima and Nagasaki are --18 and 15%, respectively. The estimated uncertainties vary only slightly by ground range and are fairly highly correlated. The total prompt kerma uncertainties are dominated by the secondary gamma uncertainties, which in turn are dominated by the modeling parameter uncertainties, particularly those associated with the weapon yield and radiation sources

  6. Product kerma in the air-area and radiation dose in dental radiodiagnosis

    International Nuclear Information System (INIS)

    The main purpose of patient dosimetry in diagnostic radiology is to determine dosimetric quantities for the establishment and use of reference levels and comparative risk assessment. In recent publications the use of the air kerma-area product, PKA, has been suggested in dental radiology, as this quantity is more closely related to risk. The aim of this study was to perform a preliminary survey of PKA and effective dose in different types of dental examinations. The future perspective is a large-scale survey for the establishment and use of diagnostic reference levels in dentistry in Brazil. (author)

  7. From Reference Air Kerma Rate to Nominal Absorbed Dose Rate to Water: Paradigm Shift in Photon Brachytherapy

    International Nuclear Information System (INIS)

    In brachytherapy (BT), photon radiation sources are presently calibrated in terms of the reference air kerma rate Kδ (or air kerma strength SK). By direct source calibration in terms of Dw,1, the nominal absorbed dose rate to water at the TG-43U1 reference position at 1 cm in water and with the ability to measure distributions of this quantity, the accuracy of clinical BT-dosimetry should increase due to decreased calibration uncertainties compared to present methods. Several Dw,1 primary standards are under development for high energy, high dose rate and low energy, low dose rate sources. To provide worldwide traceability and guidance for clinical medical physicists, an ISO standardization project, Clinical Dosimetry - Photon Radiation Sources Used in Brachytherapy, is considered, in continuation of ISO 21439 (2009) for beta sources. Clear terms and definitions are fundamental. Reclassification of BT-photon radiation qualities is also needed, introducing a range of medium energy photons with mean energies between 40 keV and 150 keV. Radionuclide BT-sources and electronic X ray BT-sources, BT-detectors and BT-phantoms should be characterized by sets of reference data, through which the clinical medical physicist could critically evaluate the data supplied by the manufacturer, prior to clinical application. Plastic scintillators have the potential for transfer standards of high accuracy and for verification measurements of BT-source output in phantoms. Based on and extending the AAPM TG-43U1 formalism, this planned ISO-standard will provide guidance for clinical BT-dosimetry in terms of absorbed dose to water and for estimating the uncertainties. (author)

  8. Product kerma in the air-area and radiation dose in dental radiodiagnosis; Produto kerma ar-area e dose efetiva em radiodiagnostico odontologico

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Alessandro Martins da, E-mail: amcosta@usp.br [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica

    2014-07-01

    The main purpose of patient dosimetry in diagnostic radiology is to determine dosimetric quantities for the establishment and use of reference levels and comparative risk assessment. In recent publications the use of the air kerma-area product, PKA, has been suggested in dental radiology, as this quantity is more closely related to risk. The aim of this study was to perform a preliminary survey of PKA and effective dose in different types of dental examinations. The future perspective is a large-scale survey for the establishment and use of diagnostic reference levels in dentistry in Brazil. (author)

  9. Air kerma strength calibration of 0.6 cc Farmer chamber for 192Ir HDR source

    International Nuclear Information System (INIS)

    One of the methods adopted by hospitals for the calibration of the HDR 192Ir source, in terms of Air Kerma Strength (AKS) is to use 0.6cc chamber at short source to chamber distances for measuring the air kerma rate at the chamber position and then compute the AKS using the appropriate correction factors. However, the 0.6 cc Farmer type chambers purchased by the users for the calibration of the HDR 192Ir source, are not generally provided with an HDR 192Ir calibration factor. With the result, many hospitals that have purchased the Farmer type chamber for the calibration of 192Ir HDR sources, use the 60Co calibration factor for this purpose. The use of 60Co calibration factor for the 192Ir HDR source would unnecessarily increase the uncertainty of the measured AKS. Again, because of the low chamber sensitivity, hospitals often use, source to chamber distances as small as a few cm for calibrating the 192Ir HDR source. In the absence of a rigid source-chamber positioning system, this can lead to several percent errors in AKS determination. Also, hospitals often don't take into account corrections for the room scatter or the fluence non-uniformity across the chamber, which further increase the uncertainty of the measured AKS

  10. Determination of the conversion coefficient for ambient dose equivalent, H(10), from air kerma measurements

    International Nuclear Information System (INIS)

    Namely the operational magnitudes can be determined by the product of a conversion coefficient by exposure air kerma or fluence, etc. In particular in Mexico for the first time is determined the conversion coefficient (Cc) for operational magnitude Environmental Dose Equivalent H(10) by thermoluminescence dosimetry (TLD) technique. First 30 TLD-100 dosimeters are calibrated in terms of air kerma, then these dosimeters are irradiated inside a sphere ICRU type of PMMA and with the aid of theory cavity the absorbed dose in PMMA is determined at a depth of 10 mm within the sphere DPMMA(10), subsequently absorbed dose to ICRU tissue is corrected and the dose equivalent H(10) is determined. The Cc is determined as the ratio of H(10)/Ka obtaining a value of 1.20 Sv Gy-1 with a uc= 3.66%, this being consistent with the published value in ISO-4037-3 of 1.20 Sv Gy-1 with a uc= 2%. (Author)

  11. Kerma rate evaluation in the air in a room interventional cardiology

    International Nuclear Information System (INIS)

    In recent years, the number of interventional cardiology procedures is increasing. However, due to the long time of fluoroscopy in these procedures, care teams can receive high doses of radiation. The radiation scattered by the patient is not uniform, and their assessment is of utmost importance. This study aimed to estimate and map the kerma rate in the air at the time of the gonads, in an interventional cardiology room, seeking to optimize the dose absorbed by individuals occupationally exposed to ionizing radiation. For data collection, the room was divided into quadrants of 1m2, totaling 40 collection points. The simulator was positioned so that its entry surface was located in the interventional reference point. Were chosen the conditions that simulate angiography and angioplasty procedures performed in the service. The data were obtained for height of 1 meter, gonad region. The results obtained for kerma rates in air, in quadrants, show that higher measured values was in the vicinity of the X-ray tube. Has been found that the medical staff are more exposed, because of its location during the procedure, around the table. The law of the inverse square distance of the farthest points of the X-ray tube were verified

  12. Air-kerma evaluation at the maze entrance of HDR brachytherapy facilities

    International Nuclear Information System (INIS)

    In the absence of procedures for evaluating the design of brachytherapy (BT) facilities for radiation protection purposes, the methodology used for external beam radiotherapy facilities is often adapted. The purpose of this study is to adapt the NCRP 151 methodology for estimating the air-kerma rate at the door in BT facilities. Such methodology was checked against Monte Carlo (MC) techniques using the code Geant4. Five different facility designs were studied for 192Ir and 60Co HDR applications to account for several different bunker layouts. For the estimation of the lead thickness needed at the door, the use of transmission data for the real spectra at the door instead of the ones emitted by 192Ir and 60Co will reduce the lead thickness by a factor of five for 192Ir and ten for 60Co. This will significantly lighten the door and hence simplify construction and operating requirements for all bunkers. The adaptation proposed in this study to estimate the air-kerma rate at the door depends on the complexity of the maze: it provides good results for bunkers with a maze (i.e. similar to those used for linacs for which the NCRP 151 methodology was developed) but fails for less conventional designs. For those facilities, a specific Monte Carlo study is in order for reasons of safety and cost-effectiveness. (paper)

  13. Image quality and volume computed tomography air kerma index (C{sub vol}) evaluation in Recife; Avaliacao da qualidade de imagem e do indice volumetrico de Kerma ar em tomografia computadorizada (C{sub vol}) em Recife

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Marcos Ely Almeida

    2008-07-01

    The Computed Tomography (CT) is an important diagnostic imaging method, widely used. However, in spite of all the advantages and technologic advances within the CT scanners, the tomographic procedures result in high absorbed doses to patients. The main objective of this work was to perform a dosimetric study of CT scanners located at Recife and to evaluate the image quality on CT examinations in these equipment. The volume CT air kerma index (C{sub VOL}) and air kerma length product (P{sub KL,CT}) were estimated. These values were calculated using normalized weighted air kerma indexes in CT standard dosimetry phantoms ({sub n}C{sub W}), supplied by ImPACT group for several CT scanners, and the scan parameters of routine head, routine chest and hi-resolution chest CT exams performed at 20 institutions. The irradiation parameters of 15 adult patients for each CT procedure were registered at six participating centres, at which the phantom from the American College of Radiology (ACR) CT accreditation protocol was used for the image quality measurements. For routine head exams, the C{sub VOL} values varied between 12 and 58 mGy (at the posterior fossa) and 15 to 58 mGy (at the cerebrum) and the P{sub KL,CT}, from 150 to 750 mGy{center_dot}cm. The C{sub VOL} values for routine chest procedures varied from 3 to 26 mGy and the P{sub KL,CT}, between 120 and 460 mGy{center_dot}cm. In relation to Hi-resolution chest exams, C{sub VOL} values were from 1.0 to 2.7 mGy and the P{sub KL,CT} values varied between 24 and 67 mGy{center_dot}cm. The image quality evaluations results showed that almost all scanners presented at least one inadequacy. One of the equipment presented faults at 70% of the tests. With regard to the image noise, only two scanners presented acceptable results. From these results, it is possible to conclude that the volume CT air kerma index values are lower than the European reference levels. However, the image quality of these CT scanners does not attend the

  14. Kerma rate evaluation in the air in a room interventional cardiology; Avaliacao da taxa de Kerma no ar em uma sala de cardiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Real, Jessica V.; Luz, Renata M. da, E-mail: jessica.real@pucrs.br, E-mail: renata.luz@pucrs.br [Hospital Sao Lucas (HSL/PUCRS), Porto Alegre, RS (Brazil); Fröhlich, Bruna D.; Silva, Ana Maria Marques da, E-mail: bruna.frohlich@acad.pucrs.br, E-mail: ana.marques@pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil)

    2014-07-01

    In recent years, the number of interventional cardiology procedures is increasing. However, due to the long time of fluoroscopy in these procedures, care teams can receive high doses of radiation. The radiation scattered by the patient is not uniform, and their assessment is of utmost importance. This study aimed to estimate and map the kerma rate in the air at the time of the gonads, in an interventional cardiology room, seeking to optimize the dose absorbed by individuals occupationally exposed to ionizing radiation. For data collection, the room was divided into quadrants of 1m{sup 2}, totaling 40 collection points. The simulator was positioned so that its entry surface was located in the interventional reference point. Were chosen the conditions that simulate angiography and angioplasty procedures performed in the service. The data were obtained for height of 1 meter, gonad region. The results obtained for kerma rates in air, in quadrants, show that higher measured values was in the vicinity of the X-ray tube. Has been found that the medical staff are more exposed, because of its location during the procedure, around the table. The law of the inverse square distance of the farthest points of the X-ray tube were verified.

  15. Conversion coefficients from air kerma to personal dose equivalent Hp(3) fir eye-lens dosimetry

    International Nuclear Information System (INIS)

    This work has been performed within the frame of the European Union ORAMED project (Optimization of Radiation protection for Medical staff). The main goal of the project is to improve standards of protection for medical staff for procedure resulting in potentially high exposures and to develop methodologies for better assessing and for reducing exposures to medical staff. The Work Package WP2 is involved in the development of practical eye lens dosimetry in interventional radiology. This study is complementary of the part of the ENEA report concerning the calculations with the MCNP code of the conversion factors related to the operational quantity Hp(3). A set of energy and angular dependent conversion coefficients Hp(3)/Kair in the new proposed square cylindrical phantom of ICRU tissue, have been calculated with the Monte-Carlo code PENELOPE. The Hp(3) values have been determined in terms of absorbed dose, according to the definition of this quantity, and also with the kerma approximation as formerly reported in ICRU reports. At low photon energy, up to 1 MeV, the two sets of conversion coefficients are consistent. Nevertheless, the differences increase at higher energy. This is mainly due to the lack of electronic equilibrium, especially for small angle incidences. The values of the conversion coefficients obtained with the code MCNP published by ENEA, agree with the kerma approximation calculations with PENELOPE. They are coherent with previous calculations in phantoms different in shape. But above 1 MeV, differences between conversion coefficient values calculated with the absorbed dose and with kerma approximation are significantly increasing, especially at low incidence angles. At those energies the electron transport has to be simulated. (author)

  16. Evaluation of conversion coefficients relating air-kerma to H*(10) using primary and transmitted x-ray spectra in the diagnostic radiology energy range.

    Science.gov (United States)

    Santos, J C; Mariano, L; Tomal, A; Costa, P R

    2016-03-01

    According to the International Commission on Radiation Units and Measurements (ICRU), the relationship between effective dose and incident air-kerma is complex and depends on the attenuation of x-rays in the body. Therefore, it is not practical to use this quantity for shielding design purposes. This correlation is adopted in practical situations by using conversion coefficients calculated using validated mathematical models by the ICRU. The ambient dose equivalent, H*(10), is a quantity adopted by the IAEA for monitoring external exposure. Dose constraint levels are established in terms of H*(10), while the radiation levels in radiometric surveys are calculated by means of the measurements of air-kerma with ion chambers. The resulting measurements are converted into ambient dose equivalents by conversion factors. In the present work, an experimental study of the relationship between the air-kerma and the operational quantity ambient dose equivalent was conducted using different experimental scenarios. This study was done by measuring the primary x-ray spectra and x-ray spectra transmitted through materials used in dedicated chest radiographic facilities, using a CdTe detector. The air-kerma to ambient dose equivalent conversion coefficients were calculated from these measured spectra. The resulting values of the quantity ambient dose equivalent using these conversion coefficients are more realistic than those available in the literature, because they consider the real energy distribution of primary and transmitted x-ray beams. The maximum difference between the obtained conversion coefficients and the constant value recommended in national and international radiation protection standards is 53.4%. The conclusion based on these results is that a constant coefficient may not be adequate for deriving the ambient dose equivalent. PMID:26835613

  17. Calculation of the uncertainty associated to the result of entrance surface air kerma for conventional radiology patients

    International Nuclear Information System (INIS)

    Radiation doses from diagnostic radiology are the largest contribution to the collective dose and the use of guidance (reference levels) has proven to be a tool for optimization of protection. Recently, with the support of the International Atomic Energy Agency (IAEA), eight countries of the Latin-American region have been working together on a programme to test methodologies for determining preliminary values of guidance levels for X-ray chest, lumbar spine and breast examinations. The approach used was to obtain entrance surface air kerma from measurements of X-ray tube outputs, corrected for distance and backscatter and later for real exposure parameters used with patients. For quality control, some of these values for a reduced number of patients were compared with direct TLD measurements directly placed on the patient during exposure. Given the number of parameters involved in the two methods, relatively large differences are deemed to be found in the comparison. The only way of deciding if measurements and calculations are outliers, for example, due to a systematic error or a mistake, is to compare these differences with the combined uncertainty. The aim of this paper is to present (in a detailed way) the methodology used in the pilot program ARCAL LXXV, the analyses of data performed within the survey and the estimated uncertainty. The parameters analyzed were: precision of the readings, positioning of the detector, reproducibility of the mAs and kV, long term stability of the instrument, radiation quality, kerma rate, radiation incidence, field size and field homogeneity, calibration factor of the equipment, temperature and pressure measurement, X-ray tube output curve adjustment, backscatter factor and focus-patient distance. The combined standard uncertainty for Ke in chest radiography in adult patients of standard complexion, was 12%, and the expanded uncertainty (k=2) was 24%. (author)

  18. Age-Dependent Dose in Organs per Unit Air Kerma Free-in-Air: Conversion Coefficients for Environmental Exposure

    International Nuclear Information System (INIS)

    Conversion coefficients from air kerma free-in-air to effective dose and dose in organs have been calculated for hermaphrodite 1, 5, 10, 15 year old children and adult anthropomorphic mathematical models. The 15 year old child phantom is also used as the adult female phantom. The irradiation geometry considered was the phantom standing on an almost infinite plane source, which is the geometry normally used for detector's calibration for environmental in situ measurements. The ADAM computer code has been modified to use the phantoms described by Cristy for the children phantoms, the adult male phantom is described in the ICRP Report 23. Thirty-six incident energies ranging from 10 keV to 10 MeV were selected for the incident radiation. (author)

  19. The ratios of effective dose to entrance skin dose to the air kerma for some medical sources

    International Nuclear Information System (INIS)

    Results are presented for the ratios of the effective dose to skin entrance dose and to air kerma for broad beams of radiation expected to be encountered by medical workers. These workers are monitored by the Personal Radiation Monitoring Service (PRMS) using thermoluminescent dosimeters worn at the front of the body to provide estimates of the entrance skin dose. Factors are given for converting estimates of entrance skin dose to effective dose as defined by the International Commission on Radiological Protection (ICRP 1991) for beams incident on the body by one of three modes-from the front of the subject, from the back of the subject or by rotation around the subject. Additional tables are also given to calculate effective dose for these beams from a measurement of air kerma free-in-air

  20. Transmission ionization chambers for measurements of air collision kerma integrated over beam area. Factors limiting the accuracy of calibration

    International Nuclear Information System (INIS)

    Kerma-area product meters (KAP meters) are frequently used in diagnostic radiology to measure the integral of air-collision kerma over an area A(∫A Kc,air dA) perpendicular to the x-ray beam. In this work, a precise method for calibrating a KAP meter to measure ∫A Kc,air dA is described and calibration factors determined for a broad range of tube potentials (40-200kV). The integral is determined using a large number of TL dosimeters spread over and outside the nominal field area defined as the area within 50% of maximum Kc,air. The method is compared to a simplified calibration method which approximates the integral by multiplying the kerma in the centre of the field by the nominal field area Anom. While the calibration factor using the precise method is independent of field area and distance from the source, that using the simplified method depends on both. This can be accounted for by field inhomogeneities caused by the heel effect, extrafocal radiation and scattered radiation from the KAP meter. The deviations between the calibration factors were as large as ±15% for collimator apertures of 5-100cm2 and distances from the source of 50 - 160 cm. The uncertainty in the calibration factor using the precise method was carefully evaluated and the expanded relative uncertainty estimated to be ±3% with a confidence level of 95%. (author)

  1. Recent regional key comparison results for air kerma and absorbed dose to water in X-rays and 60Co radiation

    International Nuclear Information System (INIS)

    Degrees of equivalence (DoE) of the national standards as a result of periodically organized supporting key or supplementary comparisons are essential to maintain the calibration and measurement capabilities CMC lines in the database of the CIPM MRA. All the primary and secondary' standard dosimetry laboratories belong to at least one of the APMP, AFRIMETS, COOMET, EURAMET, and SIM Regional Metrology Organizations. Most of their host country's NMIs have signed the CIPM MRA and these NMIs or Designated Institutes (DI) in 32 countries worldwide have published dosimetry CMC's. From these 941 claims, 222 relate to the calibration of a wide variety of dosemeters in term of air kerma or absorbed dose to water being used in diagnostic or therapy practice in hospitals. In the case of low and medium energy X-ray beam qualities, one regional key comparison (APMP.RI (I)-K3) has been published and has some results that do not fully support the stated uncertainties of the participants. The other two similar comparisons (APMP.RI (I)-K-2, SIM.RI (I)-K-2) are still ongoing. For air kerma of the 60Co beam from the APMP.RI(I)-K1, SIM.RI(I)-K1 and EURAMET.RI(I)-K1 comparisons there are two results among the twenty-one recently established DoE values that is outside the expanded uncertainty. Further technical details of regional comparisons including the stated uncertainty budgets for the calibration of a typical therapy ionization chamber will be presented in the poster. Concerning the future regional key and supplementary comparison program the most important issues are the following: - encourage the dosimetry laboratories to organise and coordinate these comparisons, - more economic arrangement of the X-ray comparisons on the basis of the generic beam qualities of the 85 standard qualities, - organization of supplementary comparisons in term of air kerma length to support the CT dose measurements, - using dedicated mammography X-ray tube for air kerma comparisons of mammography

  2. Product estimate of air kerma-area and the air kerma in the input surface of the skin of pediatric patients undergoing chest X-ray; Estimativa do produto kerma ar-area e do kerma ar na superficie de entrada da pele de pacientes pediatricos submetidos a radiografia de torax

    Energy Technology Data Exchange (ETDEWEB)

    Villa-Chan, Beatriz; Carvalho, Aline; Andrade, Marcos Ely A.; Barros, Vinicius S.M. de; Khoury, Helen J., E-mail: beatrizvillachan@gmail.com, E-mail: alinecx90@gmail.com, E-mail: marcos.ely@gmail.com, E-mail: vsmdbarros@gmail.com, E-mail: hjkhoury@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2014-07-01

    The aim of this paper is to evaluate the entrance air kerma (Ka,e) and the product air kerma-area (Pka) for chest examinations performed with pediatric patients in a large public hospital of Recife. For this study 89 examinations of patient with ages from zero to 10 years old were evaluated. The results showed that the mean Ka,e values, for patients of 0-1 years old, 1-5 years old and 5-10 years old, were, respectively, 100 mGy, 120 mGy and 100 mGy. The Pka values for newborn patients range from 11,9 to 58,4 mGy.cm{sup 2}, for patients with 1 to 5 years old range from 17 to 192 mGy.cm{sup 2}, and from 30,4 to 136,2 mGy.cm{sup 2} for patients with ages from 5 to 10 years old. The differences in the Pka values are due the different dimensions of the radiation field. For the results its possible to conclude that the Pka values are high, in special for patients with ages from 1 to 5 years old, indicating that the collimation of the radiation field is not adequate. (author)

  3. Entrance surface air kerma in x-ray systems for paediatric interventional cardiology: a national survey

    International Nuclear Information System (INIS)

    The aims of this work were to report the results of a national survey on entrance surface air kerma (ESAK) values for different phantom thicknesses and operation modes in paediatric interventional cardiology (IC) systems and to compare them with previous values. The national survey also offers suggested investigation levels (ILs) for ESAK in paediatric cardiac procedures. ESAK was measured on phantoms of 4-16 cm thickness of polymethyl methacrylate slabs. For low fluoroscopy mode (FM), ESAK rates ranged from 0.11 to 33.1 mGy min-1 and for high FM from 0.34 to 61.0 mGy min-1. For cine mode, values of ESAK per frame were from 1.9 to 78.2 μGy fr-1. The ILs were suggested as the third quartile of the values measured. This research showed lower ESAK values than in previous research, particularly for ESAK values in cine modes. This work represents a first step towards launching a national programme in paediatric dosimetry for IC procedures. (authors)

  4. Evaluation of the entrance surface air kerma in mammographic examinations in Rio de Janeiro (Brazil)

    International Nuclear Information System (INIS)

    The aim of this work was to evaluate the distribution of the entrance surface air kerma (ESAK) and the average glandular dose (DG) in four mammography facilities located in the city of Rio de Janeiro. The ESAK values were estimated from the X-ray tube output rate (mGy/mAs) parameters. The image quality was evaluated by the radiologists in each clinic. The ESAK values obtained for a breast thickness of 45 mm were 5.58 mGy in Clinic A, 10.07 mGy in Clinic B, 13.89 mGy in Clinic C and 7.21 mGy in Clinic D. For DG, it can be seen that, for the same compressed breast thickness (50 mm), the value varied from 0.20 to 3.60 mGy, with a mean value of 1.50 mGy for all the clinics. In image quality evaluation, Clinic D was the only one that presented a very low acceptability for quality criteria and inadequacies in relation to specks, masses and optical density. (authors)

  5. Calculation of conversion factor of Kerma in the air for ambient dose equivalent in radiotherapy

    International Nuclear Information System (INIS)

    This work aims to estimate the average conversion factor of Kerma in air to H * (10) using photon beams coming from clinic linear accelerators, transmitted through concrete walls of a radiotherapic treatment room. The transmitted photon spectra by both 1 meter and 2 meters concrete walls, in an area of 40 x 40 cm2, were calculated when the primary beam impart in an angle of 0 deg. The (secondary) photon beams transmitted respectively by 0,5 meter, 1,0 meter, 1,0 meter and 2,0 meter concrete walls, after they scattered by an angle of 90 deg in a cylindric phantom inside the room, were also determined. Generally, 50 millions of histories were computed for each simulation made for the primary beam. For the 90 deg spread, the number of histories was 100 millions. The computational code used on this work was the MCNP4B. The most common clinic accelerators used on radiotheraphic treatments were used on this work CLINAC-4, CLINAC-6, CLINAC-18 and CLINAC-2500. From the spectra analysis obtained in this work, it was possible to dispose the conversion factor for realistic beams found in radiotherapeutic establishment. (author)

  6. Conversion of Airborne Gamma ray Spectra to Ground Level Air Kerma Rates

    DEFF Research Database (Denmark)

    Bargholz, Kim; Korsbech, Uffe C C

    A new method for relating airborne gamma-ray spectra to dose rates and kerma rates at ground level is presented. Dependent on flying altitude 50 m to 125 m the method gives correct results for gamma energies above 250 keV respective 350 keV. At lower energies the method underestimate the dose or ...

  7. Distribution of kerma rate in the air inside of hemodynamic room for typical projections of interventionist cardiology procedures

    International Nuclear Information System (INIS)

    The evaluation of dose to physicians involved in Interventional Cardiology (IC) is an extreme important matter due to the high and non-uniform distribution of dose values. The radiation control during each procedure is complex and the reasons for the high exposures have many different causes. Many international recommendations have already been written aiming the radiation protection optimization in IC. In Brazil, there is not any special orientation for the protection of those occupational persons, nor a specific legislation. The purpose of this work is to evaluate the air kerma rate at critical anatomic regions of the occupationally exposed staff that carry out IC procedures, in representative incidences in order to give subsidies for individual monitoring procedures implementation and to give more information about their radiation protection. The air kerma rate has been measured in the often used condition in the two more common IC procedures namely angiography and coronary angioplasty, using an adult patient simulator irradiated under RAO, LAO and AP projections for fluoro and digital acquisition modes. The measurements have been made in 45 points around the examination table at 5 different representatives heights of: eyes lens, thorax, hands, gonads and knees. AP projection shows the smaller scattered radiation contributions and a more homogeneous exposure distribution. The digital acquisition mode gives air kerma rates about 4 times higher than fluoro mode for LAO projection in the position occupied by the interventionist doctor, the anesthetist and the nursing staff. The most critical anatomic regions are: knees and gonads (without protection). On the physician hands position, values as high as 5 mGy/h have been measured, which can overpass, depending on the number of procedures done, the individual occupational annual limit. Therefore, in IC it is necessary to implement additional protection tools, elaborate safety guides (based on international experiences

  8. Determination of the conversion coefficient for ambient dose equivalent, H(10), from air kerma measurements; Determinacion del coeficiente de conversion para la dosis equivalente ambiental, H*(10), a partir de mediciones de kerma en aire

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez J, F. [UNAM, Facultad de Ciencias, Circuito Exterior, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Alvarez R, J. T., E-mail: trinidad.alvarez@inin.gob.mx [ININ, Departamento de Metrologia de Radiaciones Ionizantes, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    Namely the operational magnitudes can be determined by the product of a conversion coefficient by exposure air kerma or fluence, etc. In particular in Mexico for the first time is determined the conversion coefficient (Cc) for operational magnitude Environmental Dose Equivalent H(10) by thermoluminescence dosimetry (TLD) technique. First 30 TLD-100 dosimeters are calibrated in terms of air kerma, then these dosimeters are irradiated inside a sphere ICRU type of PMMA and with the aid of theory cavity the absorbed dose in PMMA is determined at a depth of 10 mm within the sphere D{sub PMMA}(10), subsequently absorbed dose to ICRU tissue is corrected and the dose equivalent H(10) is determined. The Cc is determined as the ratio of H(10)/K{sub a} obtaining a value of 1.20 Sv Gy{sup -1} with a u{sub c}= 3.66%, this being consistent with the published value in ISO-4037-3 of 1.20 Sv Gy{sup -1} with a u{sub c}= 2%. (Author)

  9. Air-kerma strength determination of a new directional {sup 103}Pd source

    Energy Technology Data Exchange (ETDEWEB)

    Aima, Manik, E-mail: aima@wisc.edu; Reed, Joshua L.; DeWerd, Larry A.; Culberson, Wesley S. [Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2015-12-15

    Purpose: A new directional {sup 103}Pd planar source array called a CivaSheet™ has been developed by CivaTech Oncology, Inc., for potential use in low-dose-rate (LDR) brachytherapy treatments. The array consists of multiple individual polymer capsules called CivaDots, containing {sup 103}Pd and a gold shield that attenuates the radiation on one side, thus defining a hot and cold side. This novel source requires new methods to establish a source strength metric. The presence of gold material in such close proximity to the active {sup 103}Pd region causes the source spectrum to be significantly different than the energy spectra of seeds normally used in LDR brachytherapy treatments. In this investigation, the authors perform air-kerma strength (S{sub K}) measurements, develop new correction factors for these measurements based on an experimentally verified energy spectrum, and test the robustness of transferring S{sub K} to a well-type ionization chamber. Methods: S{sub K} measurements were performed with the variable-aperture free-air chamber (VAFAC) at the University of Wisconsin Medical Radiation Research Center. Subsequent measurements were then performed in a well-type ionization chamber. To realize the quantity S{sub K} from a directional source with gold material present, new methods and correction factors were considered. Updated correction factors were calculated using the MCNP 6 Monte Carlo code in order to determine S{sub K} with the presence of gold fluorescent energy lines. In addition to S{sub K} measurements, a low-energy high-purity germanium (HPGe) detector was used to experimentally verify the calculated spectrum, a sodium iodide (NaI) scintillating counter was used to verify the azimuthal and polar anisotropy, and a well-type ionization chamber was used to test the feasibility of disseminating S{sub K} values for a directional source within a cylindrically symmetric measurement volume. Results: The UW VAFAC was successfully used to measure the S

  10. Air-kerma strength determination of a new directional 103Pd source

    International Nuclear Information System (INIS)

    Purpose: A new directional 103Pd planar source array called a CivaSheet™ has been developed by CivaTech Oncology, Inc., for potential use in low-dose-rate (LDR) brachytherapy treatments. The array consists of multiple individual polymer capsules called CivaDots, containing 103Pd and a gold shield that attenuates the radiation on one side, thus defining a hot and cold side. This novel source requires new methods to establish a source strength metric. The presence of gold material in such close proximity to the active 103Pd region causes the source spectrum to be significantly different than the energy spectra of seeds normally used in LDR brachytherapy treatments. In this investigation, the authors perform air-kerma strength (SK) measurements, develop new correction factors for these measurements based on an experimentally verified energy spectrum, and test the robustness of transferring SK to a well-type ionization chamber. Methods: SK measurements were performed with the variable-aperture free-air chamber (VAFAC) at the University of Wisconsin Medical Radiation Research Center. Subsequent measurements were then performed in a well-type ionization chamber. To realize the quantity SK from a directional source with gold material present, new methods and correction factors were considered. Updated correction factors were calculated using the MCNP 6 Monte Carlo code in order to determine SK with the presence of gold fluorescent energy lines. In addition to SK measurements, a low-energy high-purity germanium (HPGe) detector was used to experimentally verify the calculated spectrum, a sodium iodide (NaI) scintillating counter was used to verify the azimuthal and polar anisotropy, and a well-type ionization chamber was used to test the feasibility of disseminating SK values for a directional source within a cylindrically symmetric measurement volume. Results: The UW VAFAC was successfully used to measure the SK of four CivaDots with reproducibilities within 0.3%. Monte

  11. Poster — Thur Eve — 24: Commissioning and preliminary measurements using an Attix-style free air ionization chamber for air kerma measurements on the BioMedical Imaging and Therapy beamlines at the Canadian Light Source

    International Nuclear Information System (INIS)

    Synchrotron facilities, including the Canadian Light Source (CLS), provide opportunities for the development of novel imaging and therapy applications. A vital step progressing these applications toward clinical trials is the availability of accurate dosimetry. In this study, a refurbished Attix-style (cylindrical) free air chamber (FAC) is tested and used for preliminary air kerma measurements on the two BioMedical Imaging and Therapy (BMIT) beamlines at the CLS. The FAC consists of a telescoping chamber that relies on a difference measurement of collected charge in expanded and collapsed configurations. At the National Research Council's X-ray facility, a Victoreen Model 480 FAC was benchmarked against two primary standard FACs. The results indicated an absolute accuracy at the 0.5% level for energies between 60 and 150 kVp. A series of measurements were conducted on the small, non-uniform X-ray beams of the 05B1-1 (∼8 – 100 keV) and 05ID-2 (∼20 – 200 keV) beamlines for a variety of energies, filtrations and beam sizes. For the 05B1-1 beam with 1.1 mm of Cu filtration, recombination corrections of less than 5 % could only be achieved for field sizes no greater than 0.5 mm × 0.6 mm (corresponding to an air kerma rate of ∼ 57 Gy/min). Ionic recombination thus presents a significant challenge to obtaining accurate air kerma rate measurements using this FAC in these high intensity beams. Future work includes measurements using a smaller aperture to sample a smaller and thus more uniform beam area, as well as experimental and Monte Carlo-based investigation of correction factors

  12. Poster — Thur Eve — 24: Commissioning and preliminary measurements using an Attix-style free air ionization chamber for air kerma measurements on the BioMedical Imaging and Therapy beamlines at the Canadian Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D [Department of Oncology, University of Alberta, Edmonton, AB (Canada); McEwen, M; Shen, H [Ionizing Radiation Standards, National Research Council of Canada, Ottawa, ON (Canada); Siegbahn, EA [Department of Medical Physics, Stockholm University, Stockholm (Sweden); Fallone, BG; Warkentin, B [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Department of Medical Physics, Cross Cancer Institute, Edmonton, AB (Canada)

    2014-08-15

    Synchrotron facilities, including the Canadian Light Source (CLS), provide opportunities for the development of novel imaging and therapy applications. A vital step progressing these applications toward clinical trials is the availability of accurate dosimetry. In this study, a refurbished Attix-style (cylindrical) free air chamber (FAC) is tested and used for preliminary air kerma measurements on the two BioMedical Imaging and Therapy (BMIT) beamlines at the CLS. The FAC consists of a telescoping chamber that relies on a difference measurement of collected charge in expanded and collapsed configurations. At the National Research Council's X-ray facility, a Victoreen Model 480 FAC was benchmarked against two primary standard FACs. The results indicated an absolute accuracy at the 0.5% level for energies between 60 and 150 kVp. A series of measurements were conducted on the small, non-uniform X-ray beams of the 05B1-1 (∼8 – 100 keV) and 05ID-2 (∼20 – 200 keV) beamlines for a variety of energies, filtrations and beam sizes. For the 05B1-1 beam with 1.1 mm of Cu filtration, recombination corrections of less than 5 % could only be achieved for field sizes no greater than 0.5 mm × 0.6 mm (corresponding to an air kerma rate of ∼ 57 Gy/min). Ionic recombination thus presents a significant challenge to obtaining accurate air kerma rate measurements using this FAC in these high intensity beams. Future work includes measurements using a smaller aperture to sample a smaller and thus more uniform beam area, as well as experimental and Monte Carlo-based investigation of correction factors.

  13. Calculation of factors to convert from air kerma to absorbed dose to water for medium energy photons

    International Nuclear Information System (INIS)

    The IPEMB code of practice for the determination of absorbed dose for X-rays below 300 kV generating potential is a dedicated dosimetry protocol for the determination of absorbed dose based on the air kerma evaluation method for medium energy X-rays. Three separate energy ranges are dealt with in the code of practice, however, this report is only attempting to reproduce the factors in one particular range (0.5 - 4.0 nun Cu HVL) for X-rays generated at 135 and 280 kV. These X-ray qualities are used in the NPL therapy level calibration service. This new method includes the use of an air kerma calibration factor, NK, for the ionisation chamber, and the ratio of the mass-energy absorption coefficients of water to air and factors that account for the change in the response of a NE2561 ionisation chamber between calibration in air and measurement in a water phantom, kch, instead of the old F factor. This report describes the work that was undertaken to reproduce the product of the ratio of the mass-energy absorption coefficients of water to air and the kch factors. The majority of this work was carried out using Monte Carlo techniques based on the EGS4 code system. The factors calculated in this report were found to agree with values quoted in the IPEMB code of practice to within 4.2%. The quoted uncertainty for this work is 1.4% and the uncertainties for the factors quoted in the EPEMB code of practice are 3%. Hence this is reasonable agreement. Possible discrepancies in the values may be due either to limitations in the EGS4 code system, simplifications made in the chamber geometry or on the reliance on experimental data which is not quite applicable to its' use in this work. (author)

  14. Comparison of air kerma measurements for tungsten anode based mammography x-ray beam qualities (EURAMET.RI(I)-S4.1)

    Science.gov (United States)

    Csete, I.; Büermann, L.; Gomola, I.

    2016-01-01

    A comparison of the air kerma standards for x-radiation qualities used in mammography was performed between the PTB and the IAEA. Two reference-class ionization chamber types Radcal RC6M and Magna A650 of the IAEA and tungsten anode based beam qualities with Mo and Al external filtrations (W+Mo, W+Al) established at both laboratories were selected for the comparison. The calibration coefficients, NK_air, were determined for the transfer chambers at the PTB in May 2015 and before and after this at the IAEA Dosimetry Laboratory. The results show good agreement, to be well within the 0.55 % standard uncertainty of the comparison. Correction factors to determine NK_air for these beam qualities based on calibration in RQR-M mammography beam qualities, established according to the IEC 61267 standard, were also calculated for the Radcal RC6M, 10X5-6M, and Magna A650 types of chambers. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  15. Conversion coefficients from air kerma to personal dose equivalent H{sub p}(3) fir eye-lens dosimetry; Coeficients de conversion du kerma dans l'air a l'equivalent de dose individuel H{sub p}(3) pour la dosimetrie du cristalin

    Energy Technology Data Exchange (ETDEWEB)

    Daures, J.; Gouriou, J.; Bordy, J.M

    2009-07-01

    This work has been performed within the frame of the European Union ORAMED project (Optimization of Radiation protection for Medical staff). The main goal of the project is to improve standards of protection for medical staff for procedure resulting in potentially high exposures and to develop methodologies for better assessing and for reducing exposures to medical staff. The Work Package WP2 is involved in the development of practical eye lens dosimetry in interventional radiology. This study is complementary of the part of the ENEA report concerning the calculations with the MCNP code of the conversion factors related to the operational quantity H{sub p}(3). A set of energy and angular dependent conversion coefficients H{sub p}(3)/K{sub air} in the new proposed square cylindrical phantom of ICRU tissue, have been calculated with the Monte-Carlo code PENELOPE. The H{sub p}(3) values have been determined in terms of absorbed dose, according to the definition of this quantity, and also with the kerma approximation as formerly reported in ICRU reports. At low photon energy, up to 1 MeV, the two sets of conversion coefficients are consistent. Nevertheless, the differences increase at higher energy. This is mainly due to the lack of electronic equilibrium, especially for small angle incidences. The values of the conversion coefficients obtained with the code MCNP published by ENEA, agree with the kerma approximation calculations with PENELOPE. They are coherent with previous calculations in phantoms different in shape. But above 1 MeV, differences between conversion coefficient values calculated with the absorbed dose and with kerma approximation are significantly increasing, especially at low incidence angles. At those energies the electron transport has to be simulated. (author)

  16. Measurement of air kerma rates for 6- to 7-MeV high-energy gamma-ray field by ionisation chamber and build-up plate

    International Nuclear Information System (INIS)

    The 6- to 7-MeV high-energy gamma-ray calibration field by the 19F(p, αγ)16O reaction is to be served at the Japan Atomic Energy Agency. For the determination of air kerma rates using an ionisation chamber in the 6- to 7-MeV high-energy gamma ray field, the establishment of the charged particle equilibrium must be achieved during measurement. In addition to measurement of air kerma rates by the ionisation chamber with a thick build-up cap, measurement using the ionisation chamber and a build-up plate (BUP) was attempted, in order to directly determine air kerma rates under the condition of regular calibration for ordinary survey meters and personal dosemeters. Before measurements, Monte Carlo calculations were made to find the optimum arrangement of BUP in front of the ionisation chamber so that the charged particle equilibrium could be well established. Measured results imply that air kerma rates for the 6- to 7-MeV high-energy gamma-ray field could be directly determined under the appropriate condition using an ionisation chamber coupled with build-up materials. (authors)

  17. Distribution of kerma rate in the air inside of hemodynamic room for typical projections of interventionist cardiology procedures; Distribuicao da taxa de kerma no ar em uma sala de hemodinamica para projecoes tipicas de procedimentos de cardiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Mirtha Elizabet Gamarra

    2008-07-01

    The evaluation of dose to physicians involved in Interventional Cardiology (IC) is an extreme important matter due to the high and non-uniform distribution of dose values. The radiation control during each procedure is complex and the reasons for the high exposures have many different causes. Many international recommendations have already been written aiming the radiation protection optimization in IC. In Brazil, there is not any special orientation for the protection of those occupational persons, nor a specific legislation. The purpose of this work is to evaluate the air kerma rate at critical anatomic regions of the occupationally exposed staff that carry out IC procedures, in representative incidences in order to give subsidies for individual monitoring procedures implementation and to give more information about their radiation protection. The air kerma rate has been measured in the often used condition in the two more common IC procedures namely angiography and coronary angioplasty, using an adult patient simulator irradiated under RAO, LAO and AP projections for fluoro and digital acquisition modes. The measurements have been made in 45 points around the examination table at 5 different representatives heights of: eyes lens, thorax, hands, gonads and knees. AP projection shows the smaller scattered radiation contributions and a more homogeneous exposure distribution. The digital acquisition mode gives air kerma rates about 4 times higher than fluoro mode for LAO projection in the position occupied by the interventionist doctor, the anesthetist and the nursing staff. The most critical anatomic regions are: knees and gonads (without protection). On the physician hands position, values as high as 5 mGy/h have been measured, which can overpass, depending on the number of procedures done, the individual occupational annual limit. Therefore, in IC it is necessary to implement additional protection tools, elaborate safety guides (based on international experiences

  18. SU-E-P-15: Technique Factor Modulation and Reference Plane Air Kerma Rates in Response to Simulated Patient Thickness Variations for a Sample of Current Generation Fluoroscopes

    Energy Technology Data Exchange (ETDEWEB)

    Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH& Wayne State University School of Medicine, Detroit, MI (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States); Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States)

    2015-06-15

    Purpose: To evaluate and compare approaches to technique factor modulation and air kerma rates in response to simulated patient thickness variations for four state-of-the-art and one previous-generation interventional fluoroscopes. Methods: A polymethyl methacrylate (PMMA) phantom was used as a tissue surrogate for the purposes of determining fluoroscopic reference plane air kerma rates, kVp, mA, and spectral filtration over a wide range of simulated tissue thicknesses. Data were acquired for each fluoroscopic and acquisition dose curve within a default abdomen or body imaging protocol. Results: The data obtained indicated vendor- and model-specific variations in the approach to technique factor modulation and reference plane air kerma rates across a range of tissue thicknesses. Some vendors have made hardware advances increasing the radiation output capabilities of their fluoroscopes; this was evident in the acquisition air kerma rates. However, in the imaging protocol evaluated, all of the state-of-the-art systems had relatively low air kerma rates in the fluoroscopic low-dose imaging mode as compared to the previous-generation unit. Each of the newest-generation systems also employ copper filtration in the selected protocol in the acquisition mode of imaging; this is a substantial benefit, reducing the skin entrance dose to the patient in the highest dose-rate mode of fluoroscope operation. Conclusion: Understanding how fluoroscopic technique factors are modulated provides insight into the vendor-specific image acquisition approach and provides opportunities to optimize the imaging protocols for clinical practice. The enhanced radiation output capabilities of some of the fluoroscopes may, under specific conditions, may be beneficial; however, these higher output capabilities also have the potential to lead to unnecessarily high dose rates. Therefore, all parties involved in imaging, including the clinical team, medical physicists, and imaging vendors, must work

  19. SU-E-P-15: Technique Factor Modulation and Reference Plane Air Kerma Rates in Response to Simulated Patient Thickness Variations for a Sample of Current Generation Fluoroscopes

    International Nuclear Information System (INIS)

    Purpose: To evaluate and compare approaches to technique factor modulation and air kerma rates in response to simulated patient thickness variations for four state-of-the-art and one previous-generation interventional fluoroscopes. Methods: A polymethyl methacrylate (PMMA) phantom was used as a tissue surrogate for the purposes of determining fluoroscopic reference plane air kerma rates, kVp, mA, and spectral filtration over a wide range of simulated tissue thicknesses. Data were acquired for each fluoroscopic and acquisition dose curve within a default abdomen or body imaging protocol. Results: The data obtained indicated vendor- and model-specific variations in the approach to technique factor modulation and reference plane air kerma rates across a range of tissue thicknesses. Some vendors have made hardware advances increasing the radiation output capabilities of their fluoroscopes; this was evident in the acquisition air kerma rates. However, in the imaging protocol evaluated, all of the state-of-the-art systems had relatively low air kerma rates in the fluoroscopic low-dose imaging mode as compared to the previous-generation unit. Each of the newest-generation systems also employ copper filtration in the selected protocol in the acquisition mode of imaging; this is a substantial benefit, reducing the skin entrance dose to the patient in the highest dose-rate mode of fluoroscope operation. Conclusion: Understanding how fluoroscopic technique factors are modulated provides insight into the vendor-specific image acquisition approach and provides opportunities to optimize the imaging protocols for clinical practice. The enhanced radiation output capabilities of some of the fluoroscopes may, under specific conditions, may be beneficial; however, these higher output capabilities also have the potential to lead to unnecessarily high dose rates. Therefore, all parties involved in imaging, including the clinical team, medical physicists, and imaging vendors, must work

  20. Implementation of the method air-kerma product area in KAP camera calibration with reference qualities of X-ray series at the SSDL RQR of Mexico

    International Nuclear Information System (INIS)

    The X-Ray machines, at a reference laboratory for the instrument calibration in diagnostic radiology, should compliance with the ISO requirements. Sometimes there is not available as much laboratories as needed in Latin American countries. So this project shows the KAP ionization chamber implementation method using the TRS-457 radiation quality from the IAEA at the SSDL of Mexico. The KAP instruments calibration method consists in doing a substitution comparison using a standard reference with traceability to a primary laboratory and a transmission-monitoring chamber that measures the number of photons of the X-ray primary beam. A KAP chamber calibration requires a special array that consists in collocating the chamber in two different positions of its calibration process. Then, with air kerma-area product coefficient together with a corrected electrometer measure at referential conditions, the patient dosimetry magnitudes are calculated. The dosimetry necessity at hospitals always will be in function of possessing a highly reliable calibration coefficient chamber for making these measures. That dosimetry results will help in reducing the total or partial irradiation emitted to the human body of the patient. This is how stochastic risks will be lessened due to diagnostic studies. The purpose of this project is to have a synergy with calibration for making known that the SSDL of Mexico has the technical capacity to act as a link between primary standard dosimetry laboratories and the ionizing radiation equipment users who require that their KAP chamber have traceability from the primary standard to the user. (author)

  1. Attenuation factors in terms of air kerma to ambient dose equivalent and effective dose for diagnostic X rays rooms

    International Nuclear Information System (INIS)

    In the present study, the attenuation of the quantities fluence and air kerma free-in-air by various layers of lead was compared with that of the quantities effective dose, E, and ambient dose equivalent, H*(d). This work aims to calculate the attenuation factors from 50 kV, 125 kV and 150 kV of X ray beams used for medical diagnostic, after transmission through barriers of lead. The X ray qualities used were those recommended by the Birch and Marshall for primary diagnostic X rays. Several lead layers were irradiated with a 50 cm x 50 cm field of primary X ray spectra. The transmitted spectra were calculated to obtain the attenuation factors for beams found in radiodiagnostic services. The calculations were done using the MCNPX Monte Carlo code and voxel model MAX. The values obtained were compared with data derived from the literature. In addition, attenuation factors for X ray qualities after penetration of lead layers were studied to get data which might be of interest in shielding of diagnostic rooms. (author)

  2. Kerma in the air at entry surface in thorax pediatric examinations at public hospital in Parana, Brazil

    International Nuclear Information System (INIS)

    This work consisted in the evaluation of the entrance skin air kerma (ESAK) in pediatric chest x-ray examinations. A study of 186 exams in anterior-posterior, posterior-anterior and lateral projections was carried out for patients with ages ranging from 0 to 15 years. The ESAK was measured with the DoseCal software and Li-Fl thermoluminescent dosimeters. The results were compared with measurements done recently at the same place and with the reference dose values established by the European Community. It was observed that the optimization of the technique and the routine changes suggested in the previous study were not maintained. The charge (mAs) and the ESAK values found in the present study were much higher than the previous one, and the voltage (kVp) values found was lower. The results suggest that the implementation of the Quality Assurance Program could adequate these parameters to the established levels and keep the pediatric examinations more uniform. (author)

  3. From reference air-kerma-rate to nominal absorbed dose-rate to water Paradigm shift in photon brachytherapy: ISO new work item proposal

    International Nuclear Information System (INIS)

    Full text: Over decades, photon radiation brachytherapy (BT) has proven worldwide as an essential modality of high precision radiation oncology for certain primary tumor sites. The dosimetric uncertainty of photon brachytherapy, however, is currently much larger than in external beam radiotherapy due to several factors including: calibration to the reference air-kerma-rate K.R K.R (or air-kerma strength), dose calculation model, dosimetric functions and dose measurement complexity, besides the geometrical dose uncertainties in high dose-gradient BT-fields. In addition, many photon sources are applied with quite different dosimetric properties requiring much skill from the medical physicist. This work proposes increased accuracy of brachytherapy through improvements in source calibration and clinical dosimetry methodology. Currently, BT-photon sources are calibrated free in air, at 100 cm distance, and in terms of K.R. By calibrating BT-photon sources directly to the TG-43U1 reference point at 1 cm in water, to be named the nominal absorbed dose-rate to water, D.w,1, the number of calibration steps in the traceability chain is reduced from 6 to 4, thus reducing the expanded uncertainty in dose delivery for patient treatment. With a target combined uncertainty of ucue.w,1 primary standards, which will soon become available for high energy and low energy, high and low dose-rate BT-photon sources. This is a paradigm shift that requires: international consensus, metrologic work and guidance. Thus, there is a need for an ISO standard based on and extending the AAPM TG-43U1 formalism. Taking into account the results and conclusions of the AAPM 2010 discussions, a draft for an ISO new work item proposal on Clinical dosimetry - Photon radiation sources for brachytherapy will be presented. This standardization project could be launched within ISO TC 85/SC 2/WG 22, in continuation of ISO 21439 (2009) for beta radiation sources. Clear terms and definitions are basic

  4. Control letters and uncertainties of the kerma patterns in air, dose absorbed in water and dose absorbed in air of the LSCD

    International Nuclear Information System (INIS)

    With the purpose of characterizing the component of uncertainty of long term of the patron ionization chambers of the LSCD, for the magnitudes: speed of kerma in air Κα·, dose speed absorbed in water Dα·, and speed absorbed dose in air Dα·, it use the technique of letters of control l-MR/S. This statistical technique it estimates the component of uncertainty of short term by means of the deviation standard inside groups σω and that of long term by means of the standard deviation among groups σβ, being this it finishes an estimator of the stability of the patterns.The letters of control l-MR/S it construct for: i) Κα·, in radiation field of 60Co for patterns: primary CC01 series 131, secondary NE 2611 series 176, secondary PTW TN30031 series 578 and Third PTW W30001 series 365. ii) Dα),en radiation field of 60Co for patterns: primary CC01 series 131, Secondary PTW TN30031 series 578 and tertiary PTW W30001 series 365. iii) I-MR/S with extrapolation chamber PTW primary pattern, measurement realizes in secondary patron fields of 90Sr-90Y. The expanded uncertainty U it is calculated of agreement with the Guide of the ISO/BIPM being observed the following thing: a. In some the cases σβ, is the component of the U that more contributed to this. Therefore, it is necessary to settle down technical of sampling in those mensurations that allow to reduce the value of σβ. For example with sizes of subgroup η∼ 30 data, or with a number of subgroups κ≥. That which is achieved automating the mensuration processes. b.The component of the temperature is also one of those that but they contribute to the U, of there the necessity of: to recover the tracking for this magnitude of it influences and to increase the precision in the determinations of the temperature to diminish their influence in the U. c. The percentage difference of the magnitudes dosemeters carried out by it patterns are consistent with U certain. However, it is necessary to diminish the

  5. Air kerma to personal dose equivalent conversion factors for ICRU and ISO recommended slab phantoms for photons from 20 keV to 1 MeV

    International Nuclear Information System (INIS)

    The present report summarizes the studies carried out at ENEA-AMB-PRO-IRP (Institute for Radiation Protection) that were addressed to the determination of air kerma to personal dose equivalent conversion coefficients for two practical phantoms as proposed by ICRU (International Commission for Radiation Units and Measurements) and by ISO (International Standard Organization) for photon personal dosimeters' calibration procedure. The analyses, developed using the MCNP Monte Carlo code, were mainly aimed at establishing which of the two proposed phantoms better approximates the ICRU theoretical one. Furthermore a complete tabulation of the conversion coefficients is supplied for monoenergetic photon beams from 20 keV to 1 MeV as well as for the two ISO X-ray reference series Wide Spectrum and Narrow Spectrum. The study has been performed in the framework of the CEC Contract F13P-CT92-0064 'The Measurement of the Spectral and Angular Distribution of External Radiations in Workplace and Implications for Personal Dosimetry

  6. Spatial distribution of air kerma rate and impact of accelerating voltage on the quality of an ultra soft X-ray beam generated by a cold cathode tube in air

    International Nuclear Information System (INIS)

    Ultrasoft X-ray characteristic aluminum K alpha line (Al Kα with energy of 1.5 keV) is used in radiobiological experiments to study the effect of radiation on biological matter. A simple method to generate a continuous beam of those X-ray radiations is to bombarding an aluminum target with accelerated electrons using high voltage (HV). In this work, by varying the HV we study the characteristics of a photon beam generated by means of a cold cathode transmission X-ray tube. The anode is a thin (16 μm) aluminum foil supported by a copper grid. The spatial distribution of air kerma is measured using gafchromic films of HD-810 calibrated with a parallel plate free-air ionization chamber. We show that HV strongly modifies the energetic spectrum and air kerma rate as well as its uniformity and intensity in air. - Highlights: • We measured energy spectrum of X-ray beam. • We calibrate the Gafchromic films to measure air kerma of X-ray beam. • Spatial air kerma rate is determined and interpreted. • We define dimensions and position of future biological sample irradiation using Al Kα X-ray

  7. Implementation of the method air-kerma product area in KAP camera calibration with reference qualities of X-ray series at the SSDL RQR of Mexico; Implementacion del metodo producto kerma en aire-area en la calibracion de camaras KAP con calidades de referencia de rayos X de la serie RQR en el LSCD de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cejudo, Jesus; Tovar, Victor M., E-mail: jesus.cejudo@ini.gob.mx, E-mail: victor.tovar@inin.gob.mx [lnstituto Nacional de lnvestigaciones Nucleares (DMRI/LSDC/lNlN), Ocoyoacac (Mexico). Centro Nuclear Dr. Nabor Carrillo Flores. Laboratorio Secundario de Calibracion Dosimetrica

    2013-10-01

    The X-Ray machines, at a reference laboratory for the instrument calibration in diagnostic radiology, should compliance with the ISO requirements. Sometimes there is not available as much laboratories as needed in Latin American countries. So this project shows the KAP ionization chamber implementation method using the TRS-457 radiation quality from the IAEA at the SSDL of Mexico. The KAP instruments calibration method consists in doing a substitution comparison using a standard reference with traceability to a primary laboratory and a transmission-monitoring chamber that measures the number of photons of the X-ray primary beam. A KAP chamber calibration requires a special array that consists in collocating the chamber in two different positions of its calibration process. Then, with air kerma-area product coefficient together with a corrected electrometer measure at referential conditions, the patient dosimetry magnitudes are calculated. The dosimetry necessity at hospitals always will be in function of possessing a highly reliable calibration coefficient chamber for making these measures. That dosimetry results will help in reducing the total or partial irradiation emitted to the human body of the patient. This is how stochastic risks will be lessened due to diagnostic studies. The purpose of this project is to have a synergy with calibration for making known that the SSDL of Mexico has the technical capacity to act as a link between primary standard dosimetry laboratories and the ionizing radiation equipment users who require that their KAP chamber have traceability from the primary standard to the user. (author)

  8. Calibration of dosimeters used in diagnostic radiology in terms of air kerma rate

    International Nuclear Information System (INIS)

    This study was performed to determine IEC reference radiation beam quality for calibrating dosimeters used in diagnostic radiology. Additional filtration required to establish certain IEC quality was estimated from beam transmission measurements using Al absorbers. The experiment was carried out using medical x-ray equipment at Neelain Medical Center, Khartoum. The required added filtration thickness required to establish RQA quality was estimated according to the the method described in the IEC standard. The required filtration was estimated for each of radiation quality (40, 60, 80, 100, 120,) kV. Result showed the maximum deviation of 2.3%, for the half value-layers, which complied with the standard requirement of 3%, the additional filtration required for the RQA qualities was found to as follows: 1.2 mmAL (RQA2, 40 kV), 11.0 mmAL (RQA3, 60 kV), 20.7 mmAL ( RQA4, 80 kV), 29.5 mmAL (RQA5, 100 kV) and 33.0 mmAL (AQA6, 120 kV), those qualities recommended to be applied to calibration of the diagnostic radiology measurements instruments in Sudan.(Author)

  9. Doses monitoring in radiology: calibration of air kerma-area product (PKA meters

    Directory of Open Access Journals (Sweden)

    Ricardo Andrade Terini

    2013-12-01

    Full Text Available Objective The authors have sought to study the calibration of a clinical PKA meter (Diamentor E2 and a calibrator for clinical meters (PDC in the Laboratory of Ionizing Radiation Metrology at Instituto de Energia e Ambiente - Universidade de São Paulo. Materials and Methods Different qualities of both incident and transmitted beams were utilized in conditions similar to a clinical setting, analyzing the influence from the reference dosimeter, from the distance between meters, from the filtration and from the average beam energy. Calibrations were performed directly against a standard 30 cm3 cylindrical chamber or a parallel-plate monitor chamber, and indirectly against the PDC meter. Results The lowest energy dependence was observed for transmitted beams. The cross calibration between the Diamentor E2 and the PDC meters, and the PDC presented the greatest propagation of uncertainties. Conclusion The calibration coefficient of the PDC meter showed to be more stable with voltage, while the Diamentor E2 calibration coefficient was more variable. On the other hand, the PDC meter presented greater uncertainty in readings (5.0% than with the use of the monitor chamber (3.5% as a reference.

  10. Effect of fluoroscopic X-ray beam spectrum on air-kerma measurement accuracy: implications for establishing correction coefficients on interventional fluoroscopes with KAP meters.

    Science.gov (United States)

    Wunderle, Kevin A; Rakowski, Joseph T; Dong, Frank F

    2016-01-01

    The first goal of this study was to investigate the accuracy of the displayed reference plane air kerma (Ka,r) or air kerma-area product (Pk,a) over a broad spectrum of X-ray beam qualities on clinically used interventional fluoroscopes incorporating air kerma-area product meters (KAP meters) to measure X-ray output. The second goal was to investigate the accuracy of a correction coefficient (CC) determined at a single beam quality and applied to the measured Ka,r over a broad spectrum of beam qualities. Eleven state-of-the-art interventional fluoroscopes were evaluated, consisting of eight Siemens Artis zee and Artis Q systems and three Philips Allura FD systems. A separate calibrated 60 cc ionization chamber (external chamber) was used to determine the accuracy of the KAP meter over a broad range of clinically used beam qualities. For typical adult beam qualities, applying a single CC deter-mined at 100 kVp with copper (Cu) in the beam resulted in a deviation of < 5% due to beam quality variation. This result indicates that applying a CC determined using The American Association of Physicists in Medicine Task Group 190 protocol or a similar protocol provides very good accuracy as compared to the allowed ± 35% deviation of the KAP meter in this limited beam quality range. For interventional fluoroscopes dedicated to or routinely used to perform pediatric interventions, using a CC established with a low kVp (~ 55-60 kVp) and large amount of Cu filtration (~ 0.6-0.9 mm) may result in greater accuracy as compared to using the 100 kVp values. KAP meter responses indicate that fluoroscope vendors are likely normalizing or otherwise influencing the KAP meter output data. Although this may provide improved accuracy in some instances, there is the potential for large discrete errors to occur, and these errors may be difficult to identify. PMID:27167287

  11. Measurement of conversion coefficients between air Kerma and personal dose equivalent and backscatter factors for diagnostic X-ray beams; Determinacao experimental dos coeficientes de conversao de Kerma no ar para o equivalente de dose pessoal, Hp(d), e fatores de retroespalhamento em feixes de raios-x diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Rosado, Paulo Henrique Goncalves

    2008-07-01

    Two sets of quantities are import in radiological protection: the protection and operational quantities. Both sets can be related to basic physical quantities such as kerma through conversion coefficients. For diagnostic x-ray beams the conversion coefficients and backscatter factors have not been determined yet, those parameters are need for calibrating dosimeters that will be used to determine the personal dose equivalent or the entrance skin dose. Conversion coefficients between air kerma and personal dose equivalent and backscatter factors were experimentally determined for the diagnostic x-ray qualities RQR and RQA recommended by the International Electrotechnical Commission (IEC). The air kerma in the phantom and the mean energy of the spectrum were measured for such purpose. Harshaw LiF-100H thermoluminescent dosemeters (TLD) were used for measurements after being calibrated against an 180 cm{sup 3} Radcal Corporation ionization chamber traceable to a reference laboratory. A 300 mm x 300 mm x 150 mm polymethylmethacrylate (PMMA) slab phantom was used for deep-dose measurements. Tl dosemeters were placed in the central axis of the x-ray beam at 5, 10, 15, 25 and 35 mm depth in the phantom upstream the beam direction Another required parameter for determining the conversion coefficients from was the mean energy of the x-ray spectrum. The spectroscopy of x-ray beams was done with a CdTe semiconductor detector that was calibrated with {sup 133} Ba, {sup 241} Am and {sup 57} Co radiation sources. Measurements of the x-ray spectra were carried out for all RQR and RQA IEC qualities. Corrections due to the detector intrinsic efficiency, total energy absorption, escape fraction of the characteristic x-rays, Compton effect and attenuation in the detector were done aiming an the accurate determination of the mean energy. Measured x-ray spectra were corrected with the stripping method by using these response functions. The typical combined standard uncertainties of

  12. Assessment of protocols in cone-beam CT with symmetric and asymmetric beams usingeffective dose and air kerma-area product

    International Nuclear Information System (INIS)

    This study aims to evaluate and compare protocols with similar purposes in a cone beam CT scanner using thermoluminescent dosimeter (TLD) and the air kerma-area product (PKA) as the kerma index. The measurements were performed on two protocols used to obtain an image of the maxilla–mandible using the equipment GENDEX GXCB 500: Protocol [GX1] extended diameter and asymmetric beam (14 cm×8.5 cm-maxilla/mandible) and protocol [GX2] symmetrical beam (8.5 cm×8.5 cm-maxillary/mandible). LiF dosimeters inserted into a female anthropomorphic phantom were used. For both protocols, the value of PKA was evaluated using a PTW Diamentor E2 meter and the multimeter Radcal Rapidose system. The results obtained for the effective dose/PKA were separated by protocol image. [GX1]: 44.5 µSv/478 mGy cm2; [GX2]: 54.8 µSv/507 mGy cm2. Although the ratio of the diameters (14 cm/8.5 cm)=1.65, the ratio of effective dose values (44.5 µSv/54.8 µSv)=0.81, that is, the effective dose of the protocol with extended diameter is 19% smaller. The PKA values reveal very similar results between the two protocols. For the cases where the scanner uses an asymmetric beam to obtain images with large diameters that cover the entire face, there are advantages from the point of view of reducing the exposure of patients when compared to the use of symmetrical beam and/or to FOV images with a smaller diameter. - Highlights: • The study relies on the comparison of two image protocols in CBCT: symmetrical and asymmetrical FOV. • Effective dose assessment for symmetrical and asymmetrical FOV. • Measurements of air kerma-area product for CBCT with symmetrical and asymmetrical FOV

  13. Kerma in the air at entry surface in thorax pediatric examinations at public hospital in Parana, Brazil; Kerma no ar na superficie de entrada em exames pediatricos de torax em hospital publico no Parana, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Amanda; Porto, Lorena; Bunick, Ana; Paschuk, Sergei; Denyak, Valeriy, E-mail: schelin@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Schelin, Hugo; Tilly, Joao, E-mail: joao.tilly@derax.com.b [DERAX Desenvolvimento Radiologico, Curitiba, PR (Brazil); Khoury, Helen, E-mail: hjkhoury@gmail.co [Universidade Federal de Pernambuco (DOIN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Dosimetria e Instrumentacao Nuclear; Ferreira, Jose [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil)

    2011-07-01

    This work consisted in the evaluation of the entrance skin air kerma (ESAK) in pediatric chest x-ray examinations. A study of 186 exams in anterior-posterior, posterior-anterior and lateral projections was carried out for patients with ages ranging from 0 to 15 years. The ESAK was measured with the DoseCal software and Li-Fl thermoluminescent dosimeters. The results were compared with measurements done recently at the same place and with the reference dose values established by the European Community. It was observed that the optimization of the technique and the routine changes suggested in the previous study were not maintained. The charge (mAs) and the ESAK values found in the present study were much higher than the previous one, and the voltage (kVp) values found was lower. The results suggest that the implementation of the Quality Assurance Program could adequate these parameters to the established levels and keep the pediatric examinations more uniform. (author)

  14. Calculation of conversion factor of Kerma in the air for ambient dose equivalent in radiotherapy; Calculo dos fatores de conversao de Kerma no ar para equivalente de dose ambiental em radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Marco Antonio Frota

    2000-03-01

    This work aims to estimate the average conversion factor of Kerma in air to H {sup *} (10) using photon beams coming from clinic linear accelerators, transmitted through concrete walls of a radiotherapic treatment room. The transmitted photon spectra by both 1 meter and 2 meters concrete walls, in an area of 40 x 40 cm{sup 2}, were calculated when the primary beam impart in an angle of 0 deg. The (secondary) photon beams transmitted respectively by 0,5 meter, 1,0 meter, 1,0 meter and 2,0 meter concrete walls, after they scattered by an angle of 90 deg in a cylindric phantom inside the room, were also determined. Generally, 50 millions of histories were computed for each simulation made for the primary beam. For the 90 deg spread, the number of histories was 100 millions. The computational code used on this work was the MCNP4B. The most common clinic accelerators used on radiotheraphic treatments were used on this work CLINAC-4, CLINAC-6, CLINAC-18 and CLINAC-2500. From the spectra analysis obtained in this work, it was possible to dispose the conversion factor for realistic beams found in radiotherapeutic establishment. (author)

  15. Control letters and uncertainties of the kerma patterns in air, dose absorbed in water and dose absorbed in air of the LSCD; Cartas de control e incertidumbres de los patrones de kerma en aire, dosis absorbida en agua y dosis absorbida en aire del LSCD

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, M.T.; Tovar M, V.M.; Cejudo A, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2005-12-15

    With the purpose of characterizing the component of uncertainty of long term of the patron ionization chambers of the LSCD, for the magnitudes: speed of kerma in air {kappa}{sub {alpha}}{sub {center_dot}}, dose speed absorbed in water D{alpha}{sub {center_dot}}, and speed absorbed dose in air D{alpha}{sub {center_dot}}, it use the technique of letters of control l-MR/S. This statistical technique it estimates the component of uncertainty of short term by means of the deviation standard inside groups {sigma}{sub {omega}} and that of long term by means of the standard deviation among groups {sigma}{sub {beta}}, being this it finishes an estimator of the stability of the patterns.The letters of control l-MR/S it construct for: i) {kappa}{sub {alpha}}{sub {center_dot}}, in radiation field of {sup 60}Co for patterns: primary CC01 series 131, secondary NE 2611 series 176, secondary PTW TN30031 series 578 and Third PTW W30001 series 365. ii) D{alpha}),en radiation field of {sup 60}Co for patterns: primary CC01 series 131, Secondary PTW TN30031 series 578 and tertiary PTW W30001 series 365. iii) I-MR/S with extrapolation chamber PTW primary pattern, measurement realizes in secondary patron fields of {sup 90}Sr-{sup 90}Y. The expanded uncertainty U it is calculated of agreement with the Guide of the ISO/BIPM being observed the following thing: a. In some the cases {sigma}{sub {beta}}, is the component of the U that more contributed to this. Therefore, it is necessary to settle down technical of sampling in those mensurations that allow to reduce the value of {sigma}{sub {beta}}. For example with sizes of subgroup {eta}{sub {approx}} 30 data, or with a number of subgroups {kappa}{sub {>=}}. That which is achieved automating the mensuration processes. b.The component of the temperature is also one of those that but they contribute to the U, of there the necessity of: to recover the tracking for this magnitude of it influences and to increase the precision in the

  16. Use of a new breast phantom for dosimetric determination of incident air kerma and mean glandular dose in digital mammography system

    International Nuclear Information System (INIS)

    Mammography aims to achieve a high image quality associated with a dose in the patient as low as feasible. Values of average glandular dose, DG, can be obtained by means of two dosimetric methods: one based on the measurement of incident air kerma, Ki, associated with tables of conversion factors that depend on the half value layer, the thickness and the glandular composition of the breast. And the one that makes the measure directly to thermoluminescent dosimeters, TLDs, placed in a new dosimetric phantom. Thus, this study aims to determine the incident air kerma (Ki) and average glandular dose (DG) applied on patients in a digital mammography system (DR) using the phantom dosimetric developed. Another objective is to compare the results with the values of DG determined from Ki and also with the values of Ki and DG indicated in the examination of each patient by the digital mammography unit. The result of the average values measured in 77 patients with compressed breast thickness within the range of 5.5 cm and 6.5 cm, shows that the Ki values ranged around 7.9% between the methods of action. The result of the values of DG ranged around 14.7% between the two methods of action. It is observed that the estimate of DG by the software is higher than the values measured with the dosimetric phantom. (author)

  17. Estimation of mean-glandular dose from monitoring breast entrance skin air kerma using a high sensitivity metal oxide semiconductor field effect transistor (MOSFET) dosimeter system in mammography

    International Nuclear Information System (INIS)

    Estimation of mean-glandular dose (MGD) has been investigated in recent years due to the potential risks of radiation-induced carcinogenesis associated with the mammographic examination for diagnostic radiology. In this study, a new technique for immediate readout of breast entrance skin air kerma (BESAK) using high sensitivity MOSFET dosimeter after mammographic projection was introduced and a formula for the prediction of tube output with exposure records was developed. A series of appropriate conversion factors was applied to the MGD determination from the BESAK. The study results showed that signal response of the high sensitivity MOSFET exhibited excellent linearity within mammographic dose ranges, and that the energy dependence was less than 3% for each anode/filter combination at the tube potentials 25-30 kV. Good agreement was observed between the BESAK and the tube exposure output measurement for breasts thicker than 30 mm. In addition, the air kerma estimated from our prediction formula provided sufficient accuracy for thinner breasts. The average MGD from 120 Asian females was 1.5 mGy, comparable to other studies. Our results suggest that the high sensitivity MOSFET dosimeter system is a good candidate for immediately readout of BESAK after mammographic procedures

  18. Neutron kerma factors and water equivalence of some tissue substitutes

    International Nuclear Information System (INIS)

    The Kerma factors and Kerma relative to the air and water of 24 compounds that are used as tissue substitutes were calculated for neutron energies ranging from 2.53×10−8 to 29 MeV. The Kerma ratios of the tissue substitutes relative to air and water were calculated. The water equivalence of the selected tissue substitutes was observed above neutron energies of 100 eV. The Kerma ratio relative to the air for poly-vinylidene fluoride and Teflon were nearest to unity at very low energy (up to 1 eV) and above 63 eV, respectively. It was found that the natural rubber was a water-equivalent tissue substitute compound. The results of the Kerma factors in our investigation show good agreement with those published in ICRU-44. We found that at higher neutron energies, the Kerma factors and Kerma ratios of the selected tissue substitute compounds were approximately the same, but though the differences were large for energies below 100 eV. - Highlights: • We calculated the neutron kerma factors of tissue substitutes up to 29 MeV. • Water equivalence was observed above neutron energy 100 eV. • Natural rubber was found to be a water equivalent material. • Kerma factors are in agreement with those published in literatures

  19. Comparison of air kerma-length product measurements between the PTB and the IAEA for x-radiation qualities used in computed tomography (EURAMET.RI(I)-S12, EURAMET project 1327)

    International Nuclear Information System (INIS)

    A comparison of air kerma-length product determinations for standard radiation qualities defined for use in computed tomography (CT) was performed between the PTB and the IAEA as EURAMET project 1327, registered in the KCDB as the EURAMET.RI(I)-S12 comparison. A pencil type reference-class ionization chamber of the IAEA and the three RQT beam qualities established according to the IEC standard 61627:2005 were selected for the comparison. The calibration coefficients for the transfer chamber in terms of Gy cm/C at the PTB and the IAEA using the partial irradiation method recommended in the IAEA TRS 457 were determined. The results show the calibration coefficients of both laboratories were in a very good agreement of about 0.2 % well within the estimated relative standard uncertainty of the comparison of about 0.8 %. Residual correction due to the additional aperture required for partial irradiation of pencil chambers and feasibility of the full irradiation method were also studied. (authors)

  20. Neutron kerma factors, and water equivalence of some tissue substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Singh, V. P.; Badiger, N. M. [Karnatak University, Department of Physics, Dharwad, 580003 (India); Vega C, H. R., E-mail: kudphyvps@rediffmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-08-15

    The kerma factors and kerma relative to air and water of 24 compounds used as tissue substitutes were calculated for neutron energy from 2.53 x 10{sup -8} up to 29 MeV. The kerma ratio of the tissue substitutes relative to air and water were calculated by the ratio of kerma factors of the tissue substitute to air and water respectively. The water equivalence of the selected tissue substitutes was observed above neutron energies 100 eV. Kerma ratio relative to the air for Poly-vinylidene fluoride and Teflon are found to be nearest to unity in very low energy (up to 1 eV) and above 63 eV respectively. It was found that the natural rubber as a water equivalent tissue substitute compound. The results of the kerma factors in our investigation shows a very good agreement with those published in ICRU-44. We found that at higher neutron energies, the kerma factors and kerma ratios of the selected tissue substitute compounds are approximately same, but differences are large for energies below 100 eV. (Author)

  1. Standards for air monitoring calibration

    International Nuclear Information System (INIS)

    The US Department of Energy and the US Nuclear Regulatory Commission initiated a joint program to test the applicability of a performance-type testing standard. Draft American National Standards Institute (ANSI) Standard N42.17a was, because of difficulty in application, divided into three parts: (a) portable instruments, (b) air monitors, and (c) extended range. This new testing program used the criteria listed in parts a, b, and c to determine whether they could be used as the basis of an instrument qualification testing program. The results of the test were then provided to the standards committee, and appropriate changes were made in the standard. The detailed results of this testing program will be documented in the future. The purpose of this presentation is to discuss the current draft of the air monitoring standard, general test procedures, results of some of the tests, and the means by which the testing program could be implemented in the United States

  2. Development of improved free-air ionisation chamber as absolute dosimetry standard for low-energy X rays in INER

    International Nuclear Information System (INIS)

    The National Radiation Standard Laboratory of the Inst. of Nuclear Energy Research (INER) designed and constructed an improved Attix style free-air ionisation chamber (FAC) for low-energy X-ray measurements. Clinically, X rays in this energy range are used in mammography radiology. This chamber is also used to perform air-kerma measurements. The original Attix two-sectional design was redesigned by INER using the piston design. The correction factors were determined experimentally for volume estimation, ion recombination and air attenuation. The aperture transmission, wall transmission, electron loss and photon scatter correction factors were determined using Monte Carlo calculations. INER established the Bureau International des Poids et Mesures (BIPM) X-ray beam code and performed a comparison of secondary standard air-kerma calibration factors for 10-50 kV low- energy X rays to verify the experimental accuracy and measurement consistency of the improved chamber. The INER-NMIJ/National Inst. of Advanced Industrial Science and Technology (AIST) experimental results comparison using a transfer chamber yielded a difference <1.0% at the 95% confidence level in calibration factors. The overall uncertainty for the X-ray measurement in terms of air kerma was <0.6% at the 95% confidence level. These results indicated that the improved FAC is capable of serving as a primary standard as well as a trace standard in low-energy X-ray calibration services in Taiwan and even forming a basis for the future mammography X-ray air-kerma primary standard. (authors)

  3. Estudo comparativo da qualidade da imagem e do kerma, de entrada e de saída, em simulador de tórax utilizando sistemas analógico e digitalizado CR de aquisição de imagens Comparative study of image quality and entrance and exit air kerma measurements on chest phantom utilizing analog and CR digital imaging systems

    Directory of Open Access Journals (Sweden)

    Renata Matos da Luz

    2010-02-01

    Full Text Available OBJETIVO: O processo de migração de sistemas analógicos para digitalizados, para aplicações diagnósticas, requer cuidados específicos, a fim de manter a qualidade das imagens e minimizar a dose no paciente. Este trabalho tem como objetivo analisar e comparar a qualidade da imagem e o kerma num simulador não antropomórfico de tórax gerados por sistemas analógicos e digitalizados CR. MATERIAIS E MÉTODOS: Foram analisados a qualidade da imagem e o kerma, de entrada e saída, no simulador para dois equipamentos de raios X diferentes (Siemens e Emic, com diferentes sistemas de retificação de onda (12 pulsos e alta frequência. Ambos os sistemas (analógico e digitalizado estavam sendo utilizados no mesmo local. Foram geradas imagens em filme e em image plates. RESULTADOS: Foi observado aumento na tensão e/ou na carga transportada pelo tubo de raios X quando houve a migração para o sistema CR, para manutenção das características diagnósticas da imagem. Isto resultou em aumento de kerma coletado. CONCLUSÃO: As maiores diferenças determinadas (aumento de dose e redução da qualidade da imagem foram observadas no equipamento com retificação de onda de 12 pulsos e transdutor de imagem CR (image plates.OBJECTIVE: The process of migration from analog to digital imaging system requires specific attention to preserve images quality and minimizing the dose to the patients. The present study was aimed at analyzing and comparing images quality and entrance and exist air kerma measurements in a non-anthropomorphic chest phantom with analog and CR digital imaging systems. MATERIALS AND METHODS: Two different X-ray units (Siemens and Emic with different wave rectification systems (12-pulse and high-frequency were utilized in a single institution along the process of migration from analog to CR digital imaging system. Images were acquired on films and image plates. RESULTS: An increase on the X-ray tube peak voltage and/or load was observed

  4. Radiological investigations at the "Taiga" nuclear explosion site, part II: man-made γ-ray emitting radionuclides in the ground and the resultant kerma rate in air.

    Science.gov (United States)

    Ramzaev, V; Repin, V; Medvedev, A; Khramtsov, E; Timofeeva, M; Yakovlev, V

    2012-07-01

    Samples of soil and epigeic lichens were collected from the "Taiga" peaceful nuclear explosion site (61.30°N 56.60°E, the Perm region, Russia) in 2009 and analyzed using high resolution γ-ray spectrometry. For soil samples obtained at six different plots, two products of fission ((137)Cs and (155)Eu), five products of neutron activation ((60)Co, (94)Nb, (152)Eu, (154)Eu, (207)Bi) and (241)Am have been identified and quantified. The maximal activity concentrations of (60)Co, (137)Cs, and (241)Am for the soils samples were measured as 1650, 7100, and 6800 Bq kg(-1) (d.w.), respectively. The deposit of (137)Cs for the top 20 cm of soil on the tested plots at the "Taiga" site ranged from 30 to 1020 kBq m(-2); the maximal value greatly (by almost 3 orders of magnitude) exceeded the regional background (from global fallout) level of 1.4 kBq m(-2). (137)Cs contributes approximately 57% of the total ground inventory of the man-made γ-ray emitters for the six plots tested at the "Taiga" site. The other major radionuclides -(241)Am and (60)Co, constitute around 40%. Such radionuclides as (60)Co, (137)Cs, (241)Am, and (207)Bi have also been determined for the epigeic lichens (genera Cladonia) that colonized certain areas at the ground lip produced by the "Taiga" explosion. Maximal activity concentrations (up to 80 Bq kg(-1) for (60)Co, 580 Bq kg(-1) for (137)Cs, 200 Bq kg(-1) for (241)Am, and 5 Bq kg(-1) for (207)Bi; all are given in terms of d.w.) have been detected for the lower dead section of the organisms. The air kerma rates associated with the anthropogenic sources of gamma radiation have been calculated using the data obtained from the laboratory analysis. For the six plots tested, the kerma rates ranged from 50 to 1200 nGy h(-1); on average, 51% of the dose can be attributed to (137)Cs and 45% to (60)Co. These estimates agree reasonably well with the results of the in situ measurements made during our field survey of the "Taiga" site in August

  5. APMP/TCRI key comparison report of measurement of air kerma for medium-energy x-rays (APMP.RI(I)-K3)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H.; Hwang, W.S. [Institute of Nuclear Energy Research, Longtan, Taiwan (China); Kotler, L.H.; Webb, D.V. [Australian Radiation Protection and Nuclear Safety Agency, Yallambie (Australia); Buermann, L. [Physikalisch Technische Bundesanstalt, Braunschweig (Germany); Burns, D.T. [Bureau International de Poids et Mesures, 92 - Sevres (France); Takeyeddin, M. [Atomic Energy Commission, Damascus (Syrian Arab Republic); Shaha, V.V. [Bhabha Atomic Research Centre, Mumbai (India); Srimanoroth, S. [Department of Medical Sciences, Nonthaburi (Thailand); Meghzifene, A. [International Atomic Energy Agency, Vienna (Austria); Hah, S.H.; Chun, K.J. [Korea Research Institute of Standards and Science, Yusong (Korea, Republic of); Kadni, T.B. [Malaysian Nuclear Agency, Kajang (Malaysia); Takata, N. [National Metrology Institute of Japan, Tsukuba (Japan); Msimang, Z. [National Metrology Institute of South Africa, Pretoria (South Africa)

    2008-10-15

    The APMP/TCRI Dosimetry Working Group performed the APMP.RI(I)-K3 key comparison of measurement of air kerma for medium-energy x-rays (100 kV to 250 kV) between 2000 and 2003. In total, 11 institutes took part in the comparison, among which 8 were APMP member laboratories. Two commercial cavity ionization chambers were used as transfer instruments and circulated among the participants. All the participants established the 100 kV, 135 kV, 180 kV and 250 kV x-ray beam qualities equivalent to those of the BIPM. The results showed that the maximum difference between the participants and the BIPM in the medium-energy x-ray range, evaluated using the comparison data of the linking laboratories ARPANSA and PTB, is less than 1.4%. The degrees of equivalence between the participants are presented and this comparison confirms the calibration capabilities of the participating laboratories. (authors)

  6. APMP/TCRI key comparison report of measurement of air kerma for medium-energy x-rays (APMP.RI(I)-K3)

    International Nuclear Information System (INIS)

    The APMP/TCRI Dosimetry Working Group performed the APMP.RI(I)-K3 key comparison of measurement of air kerma for medium-energy x-rays (100 kV to 250 kV) between 2000 and 2003. In total, 11 institutes took part in the comparison, among which 8 were APMP member laboratories. Two commercial cavity ionization chambers were used as transfer instruments and circulated among the participants. All the participants established the 100 kV, 135 kV, 180 kV and 250 kV x-ray beam qualities equivalent to those of the BIPM. The results showed that the maximum difference between the participants and the BIPM in the medium-energy x-ray range, evaluated using the comparison data of the linking laboratories ARPANSA and PTB, is less than 1.4%. The degrees of equivalence between the participants are presented and this comparison confirms the calibration capabilities of the participating laboratories. (authors)

  7. Modelling the contribution of individual radionuclides to the total gamma air kerma rate for the sediments of the Ribble Estuary, NW England

    International Nuclear Information System (INIS)

    The aim of this study was to test the performance of a published dose-rate model, investigate the contribution of individual radionuclides to the total gamma air kerma rate (GAKR) and derive external doses to man in the Ribble Estuary, NW England. GAKRs were measured and sediment cores were collected in order to determine radionuclide specific activities with depth. The latter values were used as input data for the external dose-rate model. The model has a slight tendency to over-predict the GAKR, but, on average, the model predictions fall within ±26% of the measured value. Improvements, in the present case, might be made by accounting for core shortening and variations in soil density in the input data. The model predicted that, for exposed intertidal mud sites, a range of GAKRs between 0.011 and 0.022 μGy h-1 was attributable to Springfields discharges alone. The contribution due to 234mPa and 234Th ranged between 20 and 60%. An excess GAKR (GAKR arising from anthropogenic emissions alone) of 0.139-0.150 μGy μGy h-1, used in conjunction with relevant habit-survey data (for a potential critical group) and conversion factors, yielded a dose to man of 0.029-0.031 mSv year-1. (author)

  8. Stability results of a free air ionization chamber in standard mammography beams

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Natalia F.; Xavier, Marcos; Vivolo, Vitor; Caldas, Linda V.E., E-mail: nsilva@ipen.br, E-mail: mxavier@ipen.br, E-mail: vivolo@ipen.br, E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Free air ionization chambers are absolute dosimeters, because they can measure basic physical quantities directly without the need of their calibration in a standard radiation beam. They are used for measuring exposure and air kerma in X and gamma radiation beams. The Calibration Laboratory (LCI) of IPEN has a free air ionization chamber of the cylindrical type for low energies. The characterization of this ionization chamber was already performed and reported in a previous study. After a modification in the support of the micrometers used for the movement of the internal cylinder devices, the tests were redone. The objective of this work was to present the new alignment protocol of the free air ionization chamber in low energies of X-ray beams of standard mammography qualities, assuring the positioning reproducibility, and new results of stability tests performed with the application of this protocol will be presented. (author)

  9. Computation of conversion coefficients relating air Kerma to Hp(0.07,α), Hp(10,α), and H*(10) for x-ray narrow spectrum from 40 to 140 kV

    International Nuclear Information System (INIS)

    A computation method was implemented to predict the conversion coefficients and the angular dependence factors relating air Kerma to Hp(0.07,α), Hp(10,α), and H*(10) in an ICRU slab phantom for tungsten anode x-ray spectra for tube potentials from 40 to 140 kV. The simulation of the unfiltered x-ray spectra is based on the Boone and Seibert model. The calculation of conversion coefficients were performed for an x-ray narrow spectrum at any filtration material and tube potentials in the diagnostic radiology range. This computation method has been checked for five narrow x-ray spectra using a comparison of the results with published data given by the International Organization for Standardization (ISO), and American National Standards Institute (ANSI). In all cases, the mean deviation of the calculated mean conversion coefficients values do not exceed 1% for Hp (0.07,α) and 1.5% for Hp (10,α), except at 60 deg. where a mean deviation from the ISO values of 1.72% and of 2.27% was, respectively, found. But it is still lower than the mean deviation of 2.31% for Hp(0.07,α), and of 3.08% for Hp(10,α) observed at this angle between ISO and ANSI values. Otherwise, the computed values of conversion coefficients of H*(10) differ by only 0.41% from the ISO values. The results of this computation method can be considered satisfactory considering the accuracy required in radioprotection fields, and can allow an appreciable estimation of conversion coefficients for the narrow x-ray spectra indispensable to calibrate the personnel dosimeters in terms of the personal dose equivalent

  10. Energy dependence of the air kerma response of a liquid ionization chamber at photon energies between 8 keV and 1250 keV

    International Nuclear Information System (INIS)

    Full text: In its recent reports on cardiovascular brachytherapy the DGMP recommends the source strength of brachytherapy sources being characterized in terms of absorbed dose to water at a distance of 2 mm from the central axis of the source. As a consequence, the response of a detector suitable for characterizing such sources with respect to absorbed dose to water should depend only to a small extent on radiation energy. Additionally, the detection volume of the detector has to be sufficiently small for the necessary spatial resolution to be obtained. The liquid ionization chamber as described in seems to be a promising means for this type of measurements. The two components of the ionization liquid (TMS and isooctane) can be mixed in a ratio which ensures that the mass-energy absorption coefficient of the resulting mixture deviates from that of water by less than ±15 % down to photon energies of 10 keV. Due to the high density of the ionization medium, the spacing between the two electrodes of the ionization chamber can be made as small as a few tenths of a millimeter and still the resulting ionization current is sufficiently large. The ionization chamber used in the present investigation is a plane parallel chamber 5 mm in diameter and of 0.3 mm electrode spacing. The ionization medium is a mixture of 40 % TMS and 60 % isooctane. The irradiations were carried out with the ISO wide spectra series with tube voltages between 10 kV and 300 kV and with 137Cs and 60Co γ-radiation. As a first step, the response of the liquid ionization chamber was investigated with respect to air kerma instead of absorbed dose to water. Although the mass-energy absorption coefficient of the liquid deviates from that of air by less than ±10 % over the photon energy range, the measured chamber response varies by a factor of about 3.5. Monte Carlo calculations carried out with EGSnrc show a variation of the chamber response smaller than ±20 %. Measurements of the ion yield of the

  11. Kerma constant of gamma radiation

    International Nuclear Information System (INIS)

    The values are tabulated of the gamma kerma constant for 106 radionuclides and an energy threshold of δ=0, 10, 20 and 30 keV. The calculated values will be useful in gamma radiation protection for ease of calculation of the kerma rate from a point radiation source. The study was required in view of the consistent introduction of SI units. (author)

  12. Doses monitoring in radiology: calibration of air kerma-area product (P{sub KA}) meters; Monitoracao de doses em radiologia: a calibracao de medidores do produto kerma-area (P{sub KA})

    Energy Technology Data Exchange (ETDEWEB)

    Terini, Ricardo Andrade; Campelo, Maria Carolina de Santana; Almeida Junior, Jose Neres de, E-mail: rterini@pucsp.br [Pontificia Universidade Catolica de Sao Paulo (PUC-SP), SP (Brazil); Herdade, Silvio Bruni; Pereira, Marco Aurelio Guedes [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Instituto de Energia e Ambiente

    2013-11-15

    Materials and methods: different qualities of both incident and transmitted beams were utilized in conditions similar to a clinical setting, analyzing the influence from the reference dosimeter, from the distance between meters, from the filtration and from the average beam energy. Calibrations were performed directly against a standard 30 cm{sup 3} cylindrical chamber or a parallel-plate monitor chamber, and indirectly against the PDC meter. Results: the lowest energy dependence was observed for transmitted beams. The cross calibration between the Diamentor E2 and the PDC meters, and the PDC presented the greatest propagation of uncertainties. Conclusion: the calibration coefficient of the PDC meter showed to be more stable with voltage, while the Diamentor E2 calibration coefficient was more variable. On the other hand, the PDC meter presented greater uncertainty in readings (5.0%) than with the use of the monitor chamber (3.5%) as a reference. (author)

  13. Characterization of the new free-air primary standard for low-energy X-rays at CMI

    International Nuclear Information System (INIS)

    In 2011 a decision was made by Czech Metrology Institute to build a free-air ionization chamber (FAC) intended to be used as a primary standard of air kerma rate for low-energy X-rays (photon energy below 50 keV, including mammography X-ray qualities) in order to replace the currently used secondary ionization chamber and to decrease the uncertainty of air kerma reference value. In the period 2011–2012, the FAC has been designed, manufactured and put into operation. Its performance was tested using a calibrated secondary chamber and then by an informal comparison with a national primary standard of BEV (Austria). Physical characteristics of the FAC are described and individual correction factors are discussed focusing on computational methods utilized in their estimation. Summary of the correction factors with the uncertainty budget is presented. - Highlights: • A new primary standard for low-energy X-ray beam constructed at CMI. • Correction factors calculated by MCNPX simulations. • The chamber performance tested by an informal comparison with BEV (Austria). • The chamber considered ready for key comparison and standardization of X-ray beams

  14. Norma Primaria de calidad del aire AIR QUALITY STANDARD

    Directory of Open Access Journals (Sweden)

    PATRICIA MATUS C.

    2002-04-01

    Full Text Available Las normas primarias de calidad del aire tienen por finalidad proteger la salud de la población de la contaminación atmosférica. Ellas establecen un nivel de riesgo socialmente aceptado. Este artículo describe los antecedentes considerados durante el proceso de actualización de la regulación vigente en Chile. Detalla conceptos sobre la calidad del aire, describe los efectos en la salud de los contaminantes, y el procedimiento seguido para fijar los nuevos estándares Finaliza enumerando la norma primaria de calidad del aire, sus valores y los limites definidos para ser considerados en el ámbito de la gestión de los episodios críticos o de alta contaminaciónThe main purpose of air quality standards is to protect people health from air pollution. They establish a socially accepted level of risk. This article describes the background information considered during the process for updating the current Chilean regulation. Concepts about quality of air, and the effects of the pollutants on the health are described. The procedure followed to fix the new standards is detailed. Finally we state the primary air quality norm, its values as well as the critical limits in order to control critical events of high air pollution

  15. Remarks on KERMA Factors in ACE files

    Science.gov (United States)

    Konno, C.; Ochiai, K.; Takakura, K.; Sato, S.

    2014-04-01

    Some neutron KERMA factors in ACE files are negative and extremely large if nuclear data libraries do not keep energy-balance. The status of neutron KERMA factors in the official ACE file of ENDF/B-VII.1 is examined. As a result, it is found out that neutron KERMA factors of nuclei more than 200 in ENDF/B-VII.1 have some problems. Effects of the inadequate KERMA factor are also investigated, which are large for neutron heat while those are small for total (neutron + gamma) heat. Users who use only neutron KERMA factors should check if the factors are adequate or not before they use the factors.

  16. X Ray Spectrometry of Low Energy Photons for Determining Conversion Coefficients from Air Kerma, Ka, to Personal Dose Equivalent, Hp(10), for Radiation Qualities of the ISO Narrow Spectrum Series

    International Nuclear Information System (INIS)

    The pulse height spectra of the radiation qualities N-10 to N-120 of the ISO narrow spectrum series (N) were measured using a commercial Ge spectrometer and a specially designed lead collimator. For the unfolding of these spectra, three response matrices of the Ge spectrometer for different maximum energies and energy resolutions were calculated by the EGS4 (Electron Gamma Shower version 4) code incorporating the PRESTA and LSCAT options. Then, the pulse height spectra were unfolded with two different algorithms to check the correctness. To verify the measuring and unfolding method, the first half value layers (HVLs) were determined using small ionisation chambers and the fluence spectra. The mean photon energies were calculated, also on the basis of the fluence spectra, and compared with published values. For each radiation quality N-10 to N-120 the conversion coefficients hpK(10;N,α) from air kerma Ka to personal dose equivalent at 10mm depth, Hp (10,α), were calculated for angles of incidence α of 15, 30, 45, 60 deg. and 75 deg. between the unidirectional photon field and the normal to the slab phantom surface. Because the fluence spectra were influenced by the air density, in particular the low energy spectra, the hpK(10;N,α) values were normalised to reference conditions. Differences of up to about 88% between the hpK(10;N,α) values presented in this work and those given in ISO/FDIS 4037-3 were found. (author)

  17. Calculation of neutron kerma in tissues

    International Nuclear Information System (INIS)

    Neutron kerma of normal and tumor tissues has been calculated using the tissues elemental concentration. A program developed in Math cad contains the kerma factors of C, H, O, N, Na, Mg, P, S, Cl, K, etc. that are in normal and tumor human tissues. Having the elemental composition of any human tissue the neutron kerma can be calculated. The program was tested using the elemental composition of tumor tissues such as sarcoma, melanoma, carcinoma and adenoid cystic, also neutron kerma for adipose and muscle tissue for normal adult was calculated. The results are in agreement with those published in literature. The neutron kerma for water was also calculated because in some dosimetric calculations water is used to describe normal and tumor tissues. From this comparison was found that at larger energies kerma factors are approximately the same, but energies less than 100 eV the differences are large. (Author)

  18. Calculation of neutron kerma in tissues

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R.; Manzanares A, E. [Unidades Academicas de Estudios Nucleares, Ing. Electrica y Matematicas, Universidad Autonoma de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico)]. E-mail: rvega@cantera.reduaz.mx

    2004-07-01

    Neutron kerma of normal and tumor tissues has been calculated using the tissues elemental concentration. A program developed in Math cad contains the kerma factors of C, H, O, N, Na, Mg, P, S, Cl, K, etc. that are in normal and tumor human tissues. Having the elemental composition of any human tissue the neutron kerma can be calculated. The program was tested using the elemental composition of tumor tissues such as sarcoma, melanoma, carcinoma and adenoid cystic, also neutron kerma for adipose and muscle tissue for normal adult was calculated. The results are in agreement with those published in literature. The neutron kerma for water was also calculated because in some dosimetric calculations water is used to describe normal and tumor tissues. From this comparison was found that at larger energies kerma factors are approximately the same, but energies less than 100 eV the differences are large. (Author)

  19. A proper method of kerma-length product measurement during QC procedures in panoramic radiography

    International Nuclear Information System (INIS)

    As a relevant dose descriptor in panoramic radiography, product of kerma and length PKL is used. The introduction of PKL was recommended by NRPB. Anyway, NRPB termed this quantity dose-width product (DWP), the name product of kerma and length comes from a new dosimetry formalism being developed by IAEA and ICRU. The product of kerma and length in panoramic radiography is an integral of kerma profile created at a front side of the secondary collimator along a line perpendicular to the collimator. The PKL should be measured at a place of maximum intensity of the beam with respect to vertical direction. The signal is integrated over the whole exposure cycle as well. Currently, no dose descriptor in panoramic radiography is measured in the Czech Republic during the QC measurements. Therefore the measurement of PKL should be included in QC procedures as well. A pilot study using three different methods of PKL measurement is being done in the Czech Republic since 2005. The measurements are performed by an X ray film attached to the front side of a secondary collimator, by a column of thermoluminescent detectors (TLDs) and pencil ionization chamber placed perpendicular to the secondary collimator. The results obtained through the mentioned methods agree within 10% generally. The film based method has a significant disadvantage. Air kerma in a profile maximum reaches values up to 30 mGy. Standard X ray films have no dosimetric properties for such a high dose, because the response lies in a region of plateau at a characteristic curve of the film. Therefore, a primary collimator has to be covered by a shielding material. It increases energy dependence of the detection system naturally. An advantage of the film based method is knowledge of a complete kerma distribution within an X ray field. This information is used for proper positioning of a CT pencil ionization chamber or a stack of TLDs within an X ray beam. In the study, monochromatic films Foma Medix XBU (18x24 cm) and

  20. Air quality standards must protect public health

    Energy Technology Data Exchange (ETDEWEB)

    Norman Edelman [American Lung Association (ALA) (United States)

    2006-06-15

    Leading medical and public health organizations are deeply concerned about the proposed revisions to the National Ambient Air Quality Standard (NAAQS) that the US Environmental Protection Agency (EPA) announced in December 2005. Led by the American Lung Association (ALA), these groups are fighting to force EPA to finalize stricter standards for fine and coarse particles when the final decision is announced in September 2006. The ALA disagrees strongly with the proposal to exempt coarse particles from agriculture and mining sources, and to exclude communities with populations fewer than 100,000 from protection and monitoring requirements. ALA urges EPA to set the following health-based NAAQS for PM: Annual average PM2.5 standard of 12 {mu}mg/m{sup 3}; 24 hour average PM2.5 standard of 25 {mu}mg.m{sup 3} (99th percentile); 24-hour average PM10-2.5 standard of 25-30 {mu}g/m{sup 3} (99th percentile), applied equally to all areas of the country and to all types of particles. 72 refs., 2 figs., 1 tab.

  1. 40 CFR 52.14 - State ambient air quality standards.

    Science.gov (United States)

    2010-07-01

    ... quality standards. Any ambient air quality standard submitted with a plan which is less stringent than a national standard is not considered part of the plan. ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false State ambient air quality standards....

  2. Comparison of conversion coefficients for equivalent dose in terms of air kerma for photons using a male adult voxel simulator in sitting and standing posture with geometry of irradiation antero-posterior

    International Nuclear Information System (INIS)

    The dose conversion coefficient (DCC) is important to quantify and assess effective doses associated with medical, professional and public exposures. The calculation of DCCs using anthropomorphic simulators and radiation transport codes is justified since in-vivo measurement of effective dose is extremely difficult and not practical for occupational dosimetry. DCCs have been published by the ICRP using simulators in a standing posture, which is not always applicable to all exposure scenarios, providing an inaccurate dose estimation. The aim of this work was to calculate DCCs for equivalent dose in terms of air kerma (H/Kair) using the Visual Monte Carlo (VMC) code and the VOXTISS8 adult male voxel simulator in sitting and standing postures. In both postures, the simulator was irradiated by a plane source of monoenergetic photons in antero-posterior (AP) geometry. The photon energy ranged from 15 keV to 2 MeV. The DCCs for both postures were compared and the DCCs for the standing simulator were higher. For certain organs, the difference of DCCs were more significant, as in gonads (48% higher), bladder (16% higher) and colon (11% higher). As these organs are positioned in the abdominal region, the posture of the anthropomorphic simulator modifies the form in which the radiation is transported and how the energy is deposited. It was also noted that the average percentage difference of conversion coefficients was 33% for the bone marrow, 11% for the skin, 13% for the bone surface and 31% for the muscle. For other organs, the percentage difference of the DCCs for both postures was not relevant (less than 5%) due to no anatomical changes in the organs of the head, chest and upper abdomen. We can conclude that is important to obtain DCCs using different postures from those present in the scientific literature. - Highlights: • Scenarios of external photon exposures were performed in VMC code. • The VOXTISS8 simulator was irradiated in standing and sitting postures.

  3. Comparison of conversion coefficients for equivalent dose in terms of air kerma using a sitting and standing female adult voxel simulators exposure to photons in antero-posterior irradiation geometry

    International Nuclear Information System (INIS)

    Due to the difficulty in implementing invasive techniques for calculations of dose for some exposure scenarios, computational simulators have been created to represent as realistically as possible the structures of the human body and through radiation transport simulations to obtain conversion coefficients (CCs) to estimate dose. In most published papers simulators are implemented in the standing posture and this may not describe a real scenario of exposure. In this work we developed exposure scenarios in the Visual Monte Carlo (VMC) code using a female simulator in standing and sitting postures. The simulator was irradiated in the antero-posterior (AP) geometry by a plane source of monoenergetic photons with energy from 10 keV to 2 MeV. The conversion coefficients for equivalent dose in terms of air kerma (HT/Kair) were calculated for both scenarios and compared. The results show that the percentage difference of CCs for the organs of the head and thorax was not significant (less than 5%) since the anatomic position of the organs is the same in both postures. The percentage difference is more significant to the ovaries (71% for photon energy of 20 keV), to the bladder (39% at 60 keV) and to the uterus (37% at 100 keV) due to different processes of radiation interactions in the legs of the simulator when its posture is changed. For organs and tissues that are distributed throughout the entire body, such as bone (21% at 100 keV) and muscle (30% at 80 keV) the percentage difference of CCs reflects a reduction of interaction of photons with the legs of the simulator. Therefore, the calculation of conversion coefficients using simulators in the sitting posture is relevant for a more accurate dose estimation in real exposures to radiation. - Highlights: ► Scenarios of external photon exposures were performed in VMC code. ► The FAX simulator was irradiated in sitting and standing postures. ► The irradiation geometry used was the antero-posterior (AP). ► The

  4. SU-E-I-27: Estimating KERMA Area Product for CT Localizer Images

    International Nuclear Information System (INIS)

    Purpose: To estimate the free-in-air KERMA-Area Product (KAP) incident on patients due to CT localizer scans for common CT exams. Methods: In-plane beam intensity profiles were measured in localizer acquisition mode using OSLs for a 64 slice MDCT scanner (Lightspeed VCT, GE Medical Systems, Waukesha WI). The z-axis beam width was measured as a function of distance from isocenter. The beam profile and width were used to calculate a weighted average air KERMA per unit mAs as a function of intercepted x-axis beam width for objects symmetric about the localizer centerline.Patient areas were measured using manually drawn regions and divided by localizer length to determine average width. Data were collected for 50 head exams (lateral localizer only), 15 head/neck exams, 50 chest exams, and 50 abdomen/pelvis exams. Mean patient widths and acquisition techniques were used to calculate the weighted average free-in-air KERMA, which was multiplied by the patient area to estimate KAP. Results: Scan technique was 120 kV tube voltage, 10 mA current, and table speed of 10 cm/s. The mean ± standard deviation values of KAP were 120 ± 11.6, 469 ± 62.6, 518 ± 45, and 763 ± 93 mGycm2 for head, head/neck, chest, and abdomen/pelvis exams, respectively. For studies with AP and lateral localizers, the AP/lateral area ratio was 1.20, 1.33, and 1.24 for the head/neck, chest, and abdomen/pelvis exams, respectively. However, the AP/lateral KAP ratios were 1.12, 1.08, and 1.07, respectively. Conclusion: Calculation of KAP in CT localizers is complicated by the non-uniform intensity profile and z-axis beam width. KAP values are similar to those for simple radiographic exams such as a chest radiograph and represent a small fraction of the x-ray exposure at CT. However, as CT doses are reduced the localizer contribution will be a more significant fraction of the total exposure

  5. SU-E-I-27: Estimating KERMA Area Product for CT Localizer Images

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, K; Greene-Donnelly, K; Bennett, R; Thorpe, M [SUNY Upstate Medical Univ, Syracuse, NY (United States)

    2015-06-15

    Purpose: To estimate the free-in-air KERMA-Area Product (KAP) incident on patients due to CT localizer scans for common CT exams. Methods: In-plane beam intensity profiles were measured in localizer acquisition mode using OSLs for a 64 slice MDCT scanner (Lightspeed VCT, GE Medical Systems, Waukesha WI). The z-axis beam width was measured as a function of distance from isocenter. The beam profile and width were used to calculate a weighted average air KERMA per unit mAs as a function of intercepted x-axis beam width for objects symmetric about the localizer centerline.Patient areas were measured using manually drawn regions and divided by localizer length to determine average width. Data were collected for 50 head exams (lateral localizer only), 15 head/neck exams, 50 chest exams, and 50 abdomen/pelvis exams. Mean patient widths and acquisition techniques were used to calculate the weighted average free-in-air KERMA, which was multiplied by the patient area to estimate KAP. Results: Scan technique was 120 kV tube voltage, 10 mA current, and table speed of 10 cm/s. The mean ± standard deviation values of KAP were 120 ± 11.6, 469 ± 62.6, 518 ± 45, and 763 ± 93 mGycm{sup 2} for head, head/neck, chest, and abdomen/pelvis exams, respectively. For studies with AP and lateral localizers, the AP/lateral area ratio was 1.20, 1.33, and 1.24 for the head/neck, chest, and abdomen/pelvis exams, respectively. However, the AP/lateral KAP ratios were 1.12, 1.08, and 1.07, respectively. Conclusion: Calculation of KAP in CT localizers is complicated by the non-uniform intensity profile and z-axis beam width. KAP values are similar to those for simple radiographic exams such as a chest radiograph and represent a small fraction of the x-ray exposure at CT. However, as CT doses are reduced the localizer contribution will be a more significant fraction of the total exposure.

  6. Air Quality of Beijing and Impacts of the New Ambient Air Quality Standard

    OpenAIRE

    Wei Chen; Fusheng Wang; Guofeng Xiao; Kai Wu; Shixuan Zhang

    2015-01-01

    Beijing has been publishing daily reports on its air quality since 2000, and while the air pollution index (API) shows that the air quality has improved greatly since 2000, this is not the perception of Beijing’s residents. The new national ambient air quality standard (NAAQS-2012), which includes the monitoring of PM2.5, has posed stricter standards for evaluating air quality. With the new national standard, the air quality in Beijing is calculated using both NAAQS-2012 and the previous stan...

  7. 78 FR 30829 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Air Quality Standards...

    Science.gov (United States)

    2013-05-23

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Illinois; Air Quality Standards Revision AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY... current national ambient air quality standards (NAAQS) for ozone, lead, and particulate matter. EPA...

  8. Management Aspects of Implementing the New Effluent Air Monitoring Standard

    International Nuclear Information System (INIS)

    The revision to ANSI/HPS N13.1,'Sampling and Monitoring Releases of Airborne Radioactive substances From the Stacks and Ducts of Nuclear Facilities,' went into effect in January 1999 - replacing the 1969 version of the standard. There are several significant changes from the old version of the standard. The revised standard provides a new paradigm where representative air samples can be collected by extracting the sample from a single point in air streams where the contaminants are well mixed. The revised standard provides specific performance criteria and requirements for the various air sampling processes - program structure, sample extraction, transport, collection, effluent and sample flow measurement, and quality assurance. A graded approach to sampling is recommended with more stringent requirements for stacks with a greater potential to emit. These significant changes in the standard will impact the air monitoring programs at some sites and facilities. The impacts on the air monitor design, operation, maintenance, and quality control processes are discussed.

  9. Scattering study at free air ionization chamber diaphragm

    International Nuclear Information System (INIS)

    The maim of this work consisted in the assessment of the correction factor for air kerma, due to scattered radiation in the diaphragm of the free-air ionization chamber model 481. LNMRl measurements were made to acquire x-ray spectra corresponding to the Qualities RQR-M, described in IEC 61627 standards (2005). These spectra were used as input data in the MC simulations. The operational range of energy spectra provide up to 35 keV. This energy range is typically used in diagnostic radiology, although there is not primary standard for air kerma. The determination of this factor is a fundamental process in the primary standardization of the air kerma. These factors were obtained by computer simulation using the Penelope code. The results are kRQR-M1=0,9946, kRQR-M2=0,9932, kRQR-M3=0,9978 and kRQR-M4=0,9885; with uncertainties of 0,007 and coverage factor equal to 2. lt can be concluded that, with respect to the diaphragm, the chamber can be used in the primary standard of air kerma. (author)

  10. Improvement of national standard of X radiation

    International Nuclear Information System (INIS)

    At the year 1998 the Standard of X radiation air kerma and dose equivalent and their rates of the Slovak Institute of Metrology was approved and declared as the national standard. From that time there were observed considerable progress of the measuring techniques and of the measurements, too. That reflected into the several upgrading of instrumentation of this standard and improvement of its metrological parameters. At 2004 was performed the revision of the national standard of air kerma,and dose equivalent of the X radiation and their rates and it was renamed to National standard of X radiation. There have been done the some modifications, upgrading and changing of the basic or auxiliary devices and of the measuring processes. All this modification, upgrading and changing brought the simplification and the improvement to the measurements, to the calibrations and to the tests made with utilisation of the national standard of X radiation. (author)

  11. 75 FR 2938 - National Ambient Air Quality Standards for Ozone

    Science.gov (United States)

    2010-01-19

    ... 1997 (62 FR 38856) by setting the primary standard at a level of 0.08 ppm, based on the annual fourth... the air quality criteria and standards for O 3 in September 2000 with a call for information (65 FR..., and form, respectively, of the primary O 3 standard (73 FR 16472- 16475). For these reasons,...

  12. Measurement of the ambient gamma dose equivalent and kerma from the small 252Cf source at 1 meter and the small 60Co source at 2 meters

    Energy Technology Data Exchange (ETDEWEB)

    Carl, W. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-30

    NASA Langley Research Center requested a measurement and determination of the ambient gamma dose equivalent rate and kerma at 100 cm from the 252Cf source and determination of the ambient gamma dose equivalent rate and kerma at 200 cm from the 60Co source for the Radiation Budget Instrument Experiment (Rad-X). An Exradin A6 ion chamber with Shonka air-equivalent plastic walls in combination with a Supermax electrometer were used to measure the exposure rate and free-in-air kerma rate of the two sources at the requested distances. The measured gamma exposure, kerma, and dose equivalent rates are tabulated.

  13. Aqua AIRS Level 3 8-day Standard Physical Retrieval (AIRS-only) V006

    Data.gov (United States)

    National Aeronautics and Space Administration — The AIRS Only Level 3 8-Day Gridded Retrieval Product contains standard retrieval means, standard deviations and input counts. Each file covers an 8-day period, or...

  14. Air Quality of Beijing and Impacts of the New Ambient Air Quality Standard

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2015-08-01

    Full Text Available Beijing has been publishing daily reports on its air quality since 2000, and while the air pollution index (API shows that the air quality has improved greatly since 2000, this is not the perception of Beijing’s residents. The new national ambient air quality standard (NAAQS-2012, which includes the monitoring of PM2.5, has posed stricter standards for evaluating air quality. With the new national standard, the air quality in Beijing is calculated using both NAAQS-2012 and the previous standard. The annual attainment rate has dropped from 75.5% to 50.7%. The spatial analysis of air quality shows that only a background station could attain the national standard, while urban and suburban stations exceed the national standard. Among the six pollutants included in the NAAQS-2012, PM2.5 is the major contributor to the air quality index (AQI comparing with the five other pollutants. The results indicate that under previous NAAQS without PM2.5 monitoring, the air quality has improved greatly in the past decade.  By considering PM2.5, the air quality attainment has dropped greatly. Furthermore, a great effort is needed for local government to bring down the PM2.5 concentration.

  15. 75 FR 521 - National Emission Standards for Hazardous Air Pollutants: Area Source Standards for Prepared...

    Science.gov (United States)

    2010-01-05

    ... provision in 1999 in the Integrated Urban Air Toxics Strategy, (64 FR 38715, July 19, 1999). Specifically... the Integrated Urban Air Toxics Strategy (64 FR 38715, July 19, 1999). A primary goal of the Strategy... Protection Agency 40 CFR Part 63 National Emission Standards for Hazardous Air Pollutants: Area...

  16. Design of wind turbines for non-standard air density

    DEFF Research Database (Denmark)

    Soraperra, Giusepe

    2005-01-01

    different pitch angel setting; (iii) adoption of extendeders to the blades can also help in restraining the standard rated power at the standard rated speed for p less than pst. The power curves for the three turbine configurations, each in three different air density conformations, have been calculated...

  17. State Skill Standards: Heating, Ventilation, Air Conditioning, and Refrigeration

    Science.gov (United States)

    Ball, Larry; Soukup, Dennis

    2006-01-01

    The Department of Education has undertaken an ambitious effort to develop statewide career and technical education skill standards. The standards in this document are for Heating, Ventilation, Air Conditioning and Refrigeration (HVAC&R) programs and are designed to clearly state what the student should know and be able to do upon completion of an…

  18. The use of scientific information in setting ambient air standards.

    OpenAIRE

    Jordan, B C; Richmond, H M; McCurdy, T

    1983-01-01

    The Clean Air Act, as amended in 1977, requires periodic review and revision of all national ambient air quality standards (NAAQS) to insure that they are based on the latest scientific information. This article presents an overview of how EPA currently reviews and establishes NAAQS. The role of scientific information and expertise in the process is illustrated by a review of several key issues faced in the development of the proposed revisions to the carbon monoxide NAAQS. Finally, a risk an...

  19. Tissue kerma vs distance relationships for initial nuclear radiation from the atomic bombs Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Initial nuclear radiation is comprised of prompt neutrons and prompt primary gamma rays from an exploding nuclear device, prompt secondary gamma rays produced by neutron interactions in the environment, and delayed neutrons and delayed fission-product gamma rays from the fireball formed after the nuclear device explodes. These various components must all be considered in establishing tissue kerma vs distance relationships which describe the decrease of initial nuclear radiation with distance in Hiroshima and Nagasaki. An interest in initial nuclear radiation at distances of as much as 2000 m from the hypocenter demands the use of discrete ordinates transport (DOT) techniques. The two-dimensional (2D) DOT-IV code developed at Oak Ridge National Laboratory (ORNL) was used to calculate the tissue kerma in an air-over-ground geometry from prompt neutrons and prompt primary gamma rays and from prompt secondary gamma rays produced in air and in soil. Data from the Los Alamos National Laboratory (LANL) were used as the source terms. The tissue kerma at ground level from delayed fission-product gamma rays and delayed neutrons, was investigated using the NUIDEA code developed by Science Applications, Inc., (SAI). This code incorporates very detailed models which can take into account such features as the immediate rise of the fireball, the rapid radioactive decay of fission-products in it, and the perturbation of the atmosphere by the explosion. Tissue kerma vs distance relationships obtained by summing results of these current state-of-the-art calculations will be discussed. Our results clearly show that the prompt secondary gamma rays and delayed fission-product gamma rays are the dominant components of the total tissue kerma from initial nuclear radiation of the atomic (or pure-fission) devices detonated over Hiroshima and Nagasaki. (author)

  20. Calibration of the indicators of the product KERMa-AREA in radiodiagnostic equipment; Calibracion de los indicadores del producto KERMA-AREA en los equipos de radiodiagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Ginjaume, M.; Jarvinen, H.; Turak, O.

    2013-07-01

    Currently the IAEA proposes two procedures for the calibration of the determination of the PKA systems integrated in the x-ray equipment. The traditional method is to measure air kerma at a certain distance from the focus through an ionization chamber reference and then the area of the field of radiation in that position. The alternative method is based on measuring directly the product kerma-area using equipment calibrated in this magnitude. In both cases the calibration procedure takes into account the position of the tube on the stretcher of the patient. The objective of this study was to compare the practical application of both calibration procedures as well as assess the accuracy of indication of the PKA in the consoles of the radiology equipment. (Author)

  1. 76 FR 76048 - Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards

    Science.gov (United States)

    2011-12-06

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 81 RIN 2060-AR17 Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards Correction In rule document 2011-29460 appearing on pages 72097-72120 in the issues...

  2. Standards and laws for indoor air quality in Russia

    International Nuclear Information System (INIS)

    The air quality of indoor air in Russia, including the special problems of air quality with regard to radioactive contamination, is determined by a number of statutes, standards and regulations. All these are based on the biological principles that the maximum allowable concentrations of pollutants (MAC) and the prescribed radioactive safety dose limits should not be exceeded. The standards cover the air in the working zones of all ministries and departments, and are for trade unions, public and cooperative organisations and foundations. The basic Russian law for air quality is 'The Law on Environmental Nature Protection' (19.2.1991) which assures the right to health protection from adverse environmental effects. In the field of radioactive safety 'The Federal Law on Radioactive Safety' (9.1.1996) is the primary law and in accordance with it, every citizen living in Russia has the right to protection for the present and future generations from health-related deleterious effects of atomic radiation. The laws on air quality are part of the Russian Federation legal system and are secured in the Constitution. The air quality must be controlled by the Goscomgidromet and the Sunepidnadzor of Russia. In compliance with these laws everybody has the right to a favourable environment and the duty to protect, preserve and maintain it. The air environment is unique and common to all, thus economic cooperation dictates that a dedicated approach to air quality and air quality regulations would be the most appropriate way to preserve it. It appears judicious to join forces in the name of European ecological safety. To do this, it is necessary to combine the national means and secure. (author) 4 figs

  3. Survivor dosimetry. Part A. Fluence-to-kerma conversion coefficients

    International Nuclear Information System (INIS)

    An important step in the dosimetry evaluation is to relate the radiation passing through a unit volume of a material of interest (fluence) to the energy release (kerma) in the material, which determines the absorbed dose. The fluence-to-kerma conversion coefficients or 'kerma coefficients' used in the Dosimetry System 1986 (DS86) are taken from Kerr (1982). These kerma coefficients are based on body tissue compositions for Reference Man from the International Commission on Radiological Protection (1975) and Kerr (1982), the mass energy-absorption coefficients for photons from Hubbell (1982), and the elemental kerma coefficients for neutrons from Caswell et al. (1980). Hence, the kerma coefficients used in DS86 are approximately 20 years old. In order to provide an updated set of kerma coefficients for use in the Dosimetry System 2002 (DS02), a new evaluation has been completed. This new evaluation considered recently suggested changes in the composition of soft tissues of the body in ICRU Report 44 (International Commission on Radiation Units and Measurements 1989), the mass energy-absorption coefficients for photons by Hubbell and Seltzer (1996), and the elemental kerma coefficients for neutrons in ICRU Report 63 (International Commission on Radiation Units and Measurements 2000). The new DS02 kerma coefficients for soft tissue are presented as both point-wise data for use in Monte Carlo radiation transport calculations and multigroup data for use in discrete ordinates radiation transport calculations. (author)

  4. Scattering study at free air ionization chamber diaphragm; Estudo do espalhamento no diafragma da camara de ionizacao de ar livre

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Alexandre Lo Bianco dos

    2011-07-01

    The maim of this work consisted in the assessment of the correction factor for air kerma, due to scattered radiation in the diaphragm of the free-air ionization chamber model 481. LNMRl measurements were made to acquire x-ray spectra corresponding to the Qualities RQR-M, described in IEC 61627 standards (2005). These spectra were used as input data in the MC simulations. The operational range of energy spectra provide up to 35 keV. This energy range is typically used in diagnostic radiology, although there is not primary standard for air kerma. The determination of this factor is a fundamental process in the primary standardization of the air kerma. These factors were obtained by computer simulation using the Penelope code. The results are k{sub RQR-M1}=0,9946, k{sub RQR} {sub -M2}=0,9932, k{sub RQR-M3}=0,9978 and k{sub RQR-M4}=0,9885; with uncertainties of 0,007 and coverage factor equal to 2. lt can be concluded that, with respect to the diaphragm, the chamber can be used in the primary standard of air kerma. (author)

  5. Indoor air quality standards of performance applications guide

    Energy Technology Data Exchange (ETDEWEB)

    Linder, R.J.; Dorgan, C.B.; Dorgan, C.E.

    1999-07-01

    This paper discusses the development and application of standards of performance (SOPs) for HVAC and R equipment, plumbing systems, and building envelope systems in relation to maintaining acceptable indoor air quality (IAQ) in buildings. The utilization of the SOP procedure, developed in ASHRAE Research Project 853, will aid in the proper operation of systems and verify that acceptable building IAQ levels are obtained.

  6. Preparation and determination of kerma for Iridium 192 sources of low dose rate for brachytherapy

    International Nuclear Information System (INIS)

    The practice of Brachytherapy with Iridium-192 sources of low dose rate (0.4 - 0.8 Gy/h) is a technique used in the treatment of diverse illnesses. in this work the preparation, quality control and calibration are presented in terms of kerma in air of Iridium-192 using as target these recycled Iridium-Platinum wires. The targets were obtained as decayed sources of different radio therapeutical centers in the country and they were characterized by Scanning electron microscopy in order to determine their chemical composition. Subsequently it was developed an experimental design to establish the effect of neutron flux, geometrical array and irradiation time over the activity and percentage of the sources homogeneity. The homogeneity was determined by auto radiography and by Gamma spectroscopy. Once the optimal irradiation conditions were established, it is determined the apparent activity and kerma in air using a well type ionization chamber with traceability to a primary laboratory. Iridium-192 sources were obtained with an average homogeneity 96 %, apparent activity 282.129 ± 0.531 M Bq and kerma in air 0.03200 ± 0.00006 m Gy m/h A. (Author)

  7. Photon and neutron kerma coefficients for polymer gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    El-Khayatt, A.M., E-mail: Ahmed_el_khayatt@yahoo.com [Physics Department, College of Science, Al Imam Mohammad Ibn Saud Islamic University (IMSIU) (Saudi Arabia); Reactor Physics Department, Nuclear Research Centre, Atomic Energy Authority, 13759 Cairo (Egypt); Vega-Carrillo, Hector Rene [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, C. Cipres 10, Fracc. La Peñuela, 98068 Zacatecas, Zac. (Mexico)

    2015-08-21

    Neutron and gamma ray kerma coefficients were calculated for 17 3D dosimeters, for the neutron and gamma ray energy ranges extend from 2.53×10{sup −8} to 29 MeV and from 1.0×10{sup −3} to 20 MeV, respectively. The calculated kermas given here for discrete energies and the kerma coefficients are referred to as “point-wise data”. Curves of gamma ray kermas showed slight dips at about 60 keV for most 3D dosimeters. Also, a noticeable departure between thermal and epithermal neutrons kerma sets for water and polymers has been observed. Finally, the obtained results could be useful for dose estimation in the studied 3D dosimeters. - Highlights: • Neutron and gamma ray kerma coefficients were calculated in 17 3D dosimeters. • Curves of gamma-ray kermas showed slight dips at about 60 keV. • Disagreement between neutron kermas for water and polymers has been observed. • The obtained results could be useful for dose estimation in the studied dosimeters.

  8. Development of a Northern Continental Air Standard Reference Material.

    Science.gov (United States)

    Rhoderick, George C; Kitzis, Duane R; Kelley, Michael E; Miller, Walter R; Hall, Bradley D; Dlugokencky, Edward J; Tans, Pieter P; Possolo, Antonio; Carney, Jennifer

    2016-03-15

    The National Institute of Standards and Technology (NIST) recently began to develop standard mixtures of greenhouse gases as part of a broad program mandated by the 2009 United States Congress to support research in climate change. To this end, NIST developed suites of gravimetrically assigned primary standard mixtures (PSMs) comprising carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in a dry-natural air balance at ambient mole fraction levels. In parallel, the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, charged 30 aluminum gas cylinders with northern hemisphere air at Niwot Ridge, Colorado. These mixtures, which constitute NIST Standard Reference Material (SRM) 1720 Northern Continental Air, were certified by NIST for ambient mole fractions of CO2, CH4, and N2O relative to NIST PSMs. NOAA-assigned values are also provided as information in support of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) Program for CO2, CH4, and N2O, since NOAA serves as the WMO Central Calibration Laboratory (CCL) for CO2, CH4, and N2O. Relative expanded uncertainties at the 95% confidence interval are first of its kind for a gaseous SRM developed by NIST. PMID:26890890

  9. Information draft on the development of air standards for chloroform

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    Chloroform is used as a grain fumigant and a solvent for pesticides, adhesives, fats, oils, rubbers, alkaloids and waxes. It is also a chemical intermediate for dyes and pesticides, a component of cough syrups, toothpastes, and liniments. It is used in fire extinguishers, in the manufacture of refrigerants, propellants, plastics, anesthetics and pharmaceuticals. Of the releases into the air in 1996 in Ontario (36.7 tonnes), over 96 per cent was attributed to the pulp and paper industry. Chloroform is well absorbed in exposed animals and humans through ingestion, inhalation, and dermal contact. Once absorbed, the chloroform distributes throughout the entire body. Metabolism of chloroform involves cytochrome P-450 in an oxidative biotransformation to produce trichloromethanol with phosgene as its intermediate product and finally hydrochloric acid and carbon dioxide. Chloroform is a central nervous system depressant and a gastrointestinal irritant. Exposure to chloroform can cause fainting, vomiting, dizziness, nausea, fatique and headache. Its most universally observed toxic effect is liver damage. Chloroform is not known to be carcinogenic in humans, but there is sufficient evidence to suggest that it is an animal carcinogen. The current Ontario air quality standard and criterion for chloroform was established in 1979. The half-hour interim POI standard is 1,500 microgram/cubic meter, and the 24-hour AAQC is 500 microgram/cubic meter. This document reviews the scientific and technical information relevant to setting an ambient air quality standard for chloroform in Ontario. The information is gathered from standards and guidelines developed by the federal government, the US Environmental Protection Agency, the World Health Organization, Scandinavia, the Netherlands, and various American states. 59 refs., 1 tab., appendix.

  10. Nocturnal stomatal conductance and ambient air quality standards for ozone

    Science.gov (United States)

    Musselman, Robert C.; Minnick, Tamera J.

    Vegetation response to ozone depends on ozone conductance into leaves and the defensive action inside the leaf. Ozone parameters currently used for air quality standards do not incorporate conductance or defensive components. Nighttime flux has often been ignored in ozone metrics relating to plant response, since ozone concentration and conductance are considered to be minimal at night. However, ozone concentration can remain relatively high at night, particularly in mountainous areas. Although conductance is lower at night than during the day for most plants, nocturnal conductance can result in considerable ozone flux into plants. Further, plants can be more susceptible to ozone exposure at night than during the daytime, a result of lower plant defenses at night. Any ozone metric used to relate air quality to plant response should use a 24 h ozone exposure period to include the nighttime exposures. It should also incorporate plant defensive mechanisms or their surrogate.

  11. Calibration of working standard ionization chambers and dose standardization

    International Nuclear Information System (INIS)

    Measurements were performed for the calibration of two working standard ionization chambers in the secondary standard dosimetry laboratory of Sudan. 600 cc cylindrical former type and 1800 cc cylindrical radical radiation protection level ionization chambers were calibrated against 1000 cc spherical reference standard ionization chamber. The chamber were calibrated at X-ray narrow spectrum series with beam energies ranged from (33-116 KeV) in addition to 1''3''7''Cs beam with 662 KeV energy. The chambers 0.6 cc and 0.3 cc therapy level ionization were used for dose standardization and beam output calibrations of cobalt-60 radiotherapy machine located at the National Cancer Institute, University of Gazira. Concerning beam output measurements for 6''0''Co radiotherapy machine, dosimetric measurements were performed in accordance with the relevant per IAEA dosimetry protocols TRS-277 and TRS-398. The kinetic energy released per unit mass in air (air kerma) were obtained by multiplying the corrected electrometer reading (nC/min) by the calibration factors (Gy/n C) of the chambers from given in the calibration certificate. The uncertainty of measurements of air kerma were calculated for the all ionization chambers (combined uncertainty) the calibration factors of these ionization chambers then were calculated by comparing the reading of air kerma of secondary standard ionization chambers to than from radical and farmer chambers. The result of calibration working standard ionization chambers showed different calibration factors ranged from 0.99 to 1.52 for different radiation energies and these differences were due to chambers response and specification. The absorbed dose to to water calculated for therapy ionization chamber using two code of practice TRS-277 and TRS-398 as beam output for 6''0''Co radiotherapy machine and it can be used as a reference for future beam output calibration in radiotherapy dosimetry. The measurement of absorbed dose to water showed that the

  12. New Brachytherapy Standards Paradigm Shift

    International Nuclear Information System (INIS)

    The absorbed dose to water rate at short distances in water is the quantity of interest for dosimetry in radiotherapy, but no absorbed dose to water primary standards have been available to date for dosimetry of brachytherapy sources. Currently, the procedures to determine the absorbed dose imparted to the patient in brachytherapy treatments are based on measurements traceable to air kerma standards. These procedures are affected by an uncertainty that is larger than the limit recommended by the IAEA dosimetry protocol (IAEA TRS 398 (2000)). Based on this protocol, the goal for the uncertainty of the dose delivered to the target volume should be within 5% (at the level of one standard deviation) to assure the effectiveness of a radiotherapy treatment. The international protocols for the calibration of brachytherapy gamma ray sources are based on the reference air kerma rate or the air kerma strength. The absorbed dose to water, in water at the reference position around a brachytherapy source is then calculated by applying the formalism of the protocols based on a conversion constant, the dose rate constant Λ, specific for the characteristics and geometry of the brachytherapy source. The determination of this constant relies on Monte Carlo simulations and relative measurements performed with passive dosimeters, and therefore it is typically affected by large uncertainties, larger than 5% (at the level of one standard deviation). The conversion procedure needed for brachytherapy dosimetry is a source of additional uncertainty on the final value of the absorbed dose imparted to the patient. It is due to a lack of metrology standards that makes dosimetry of brachytherapy sources less accurate than dosimetry of external radiation beams produced by 60Co sources and accelerators currently used in external beam radiotherapy. This paper reviews the current developments of absorbed dose to water primary standards for brachytherapy and the rationale for the choice of the

  13. Characterization of a free-air ionization chamber in direct X-ray beams as used in mammography

    International Nuclear Information System (INIS)

    At this work stability and characterization tests were undertaken on a Victoreen free-air ionization chamber, model 481. The tests were realized using direct X-ray beams as a contribution for its establishment as a primary standard system of the quantity air kerma. The characterization tests were: saturation curve, ion collection efficiency, polarity effect, response linearity with the air kerma rate and response linearity with the chamber volume variation. The ion collection efficiency allowed the determination of the ion recombination factor. Most of the test results showed agreement with the limits established by international standards. Furthermore, the air attenuation factors for the mammography beams with aluminum and molybdenum filters were obtained. The factors for photon transmission and scattering at the diaphragm edges were also determined for mammography beams with aluminum filter and for the standard beam with molybdenum filter. (author)

  14. Deriving air quality standards on the basis of risk assessments

    International Nuclear Information System (INIS)

    A concept is proposed for deriving air quality standards on the basis of risk-dose-relationships. Five different risks are shown to be a part of any decision on the value of a definite standard. Three of these arise from the generalisation of statements on samples of objects, effects, boundary and state conditions of objects to those valid for the respective populations. These risks cannot be quantified. The remaining two risks are the risk of the incidence of effects and the risk of wrong measurements. The former risk has to be fixed by the administration while the latter results from the quality of the measurement technique. The consequences of combining these risks to a total risk are discussed. (orig.) 891 HP

  15. 77 FR 16547 - Radionuclide National Emission Standards for Hazardous Air Pollutants; Notice of Construction...

    Science.gov (United States)

    2012-03-21

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY Radionuclide National Emission Standards for Hazardous Air Pollutants; Notice of Construction... modification of sources subject to the Radionuclide National Emission Standards for Hazardous Air...

  16. 76 FR 15266 - National Emission Standards for Hazardous Air Pollutants; Notice of Reconsideration

    Science.gov (United States)

    2011-03-21

    ... Pollutants; Notice of Reconsideration AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of... aspects of the national emission standards for hazardous air pollutants (NESHAP) for new and existing... Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional...

  17. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Portable air compressor noise emission... ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors § 204.52 Portable air compressor noise emission standard. (a) Effective January 1, 1978, portable air...

  18. 40 CFR 50.8 - National primary ambient air quality standards for carbon monoxide.

    Science.gov (United States)

    2010-07-01

    ... ambient air quality standards for carbon monoxide. (a) The national primary ambient air quality standards... carbon monoxide in the ambient air shall be measured by: (1) A reference method based on appendix C and... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National primary ambient air......

  19. National Emission Standards for Hazardous Air Pollutants submittal -- 1994

    International Nuclear Information System (INIS)

    This report focuses on air quality at the Nevada Test Site (NTS) for 1994. A general description of the effluent sources are presented. Each potential source of NTS emissions was characterized by one of the following: (1) by monitoring methods and procedures previously developed at NTS; (2) by a yearly radionuclide inventory of the source, assuming that volatile radionuclides are released to the environment; (3) by the measurement of tritiated water concentration in liquid effluents discharged to containment ponds and assuming all the effluent evaporates over the course of the year to become an air emission; or (4) by using a combination of environmental measurements and CAP88-PC to calculate emissions. Appendices A through J describe the methods used to determine the emissions from the sources. These National Emission Standards for Hazardous Air Pollutants (NESHAP) emissions are very conservative, are used to calculate the effective dose equivalent to the Maximally Exposed Individual offsite, and exceed, in some cases, those reported in DOE's Effluent Information System (EIS). The NESHAP's worst-case emissions that exceed the EIS reported emissions are noted. Offsite environmental surveillance data are used to confirm that calculated emissions are, indeed, conservative

  20. National Emission Standards for Hazardous Air Pollutants submittal -- 1994

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Y.E. [ed.; Black, S.C.

    1995-06-01

    This report focuses on air quality at the Nevada Test Site (NTS) for 1994. A general description of the effluent sources are presented. Each potential source of NTS emissions was characterized by one of the following: (1) by monitoring methods and procedures previously developed at NTS; (2) by a yearly radionuclide inventory of the source, assuming that volatile radionuclides are released to the environment; (3) by the measurement of tritiated water concentration in liquid effluents discharged to containment ponds and assuming all the effluent evaporates over the course of the year to become an air emission; or (4) by using a combination of environmental measurements and CAP88-PC to calculate emissions. Appendices A through J describe the methods used to determine the emissions from the sources. These National Emission Standards for Hazardous Air Pollutants (NESHAP) emissions are very conservative, are used to calculate the effective dose equivalent to the Maximally Exposed Individual offsite, and exceed, in some cases, those reported in DOE`s Effluent Information System (EIS). The NESHAP`s worst-case emissions that exceed the EIS reported emissions are noted. Offsite environmental surveillance data are used to confirm that calculated emissions are, indeed, conservative.

  1. Reduction of air ion mobility to standard conditions

    Science.gov (United States)

    Tammet, H.

    1998-06-01

    The Langevin rule of the reduction of air ion mobility is adequate in case of zero-size ions. An alternative is the Stokes-Millikan equation that is adequate in the limit of macroscopic charged particles. The temperature variation of air ion mobility predicted by the Stokes-Millikan equation radically contradicts the Langevin rule. The temperature and pressure variation of air ion mobility is examined by using a new semiempirical model that describes the transition from the kinetic theory to the Stokes-Millikan equation. The model is valid in full mobility range. It allows to calculate at first the size of an ion according to the measured mobility and then the standard mobility according to the size. The ascent of the temperature-mobility curve on a logarithmic chart approaches the Langevin value of 1 only at very high mobilities not found in the atmosphere. The value of the ascent is 0.6 in the case of small ions of the mobility of 1.5 cm2 V-1 s-1 which brings about a considerable error when using the Langevin rule. It is recommended to store the natural values of the mobility in databases together with the values of temperature and pressure and to definitely indicate the method when the reduced mobilities are presented in publications.

  2. 77 FR 38760 - National Ambient Air Quality Standards for Particulate Matter; Correction

    Science.gov (United States)

    2012-06-29

    ... AGENCY 40 CFR Parts 50, 51, 52, 53, and 58 RIN 2060-AO47 National Ambient Air Quality Standards for... revise the national ambient air quality standards (NAAQS) for particulate matter (PM). This action...: Questions concerning the ``National Ambient Air Quality Standards for Particulate Matter'' proposed...

  3. 75 FR 35519 - Primary National Ambient Air Quality Standard for Sulfur Dioxide

    Science.gov (United States)

    2010-06-22

    ... Protection Agency 40 CFR Parts 50, 53, and 58 Primary National Ambient Air Quality Standard for Sulfur... Ambient Air Quality Standard for Sulfur Dioxide AGENCY: Environmental Protection Agency (EPA). ACTION... primary national ambient air quality standard (NAAQS) for oxides of sulfur as measured by sulfur...

  4. Humidity dependence in kerma area product meter used in diagnostic X ray examinations

    International Nuclear Information System (INIS)

    The air-kerma area product, PKA, is a dosimetric quantity that can be directly related to the patient dose and used for risk assessment associated with different x-ray examinations. PKA has the unit Gym2 and can be directly measured by use of a Kerma Area Product (KAP) meter placed in the radiation beam. PKA is the recommended quantity for use in the establishment of diagnostic reference levels (DRLs) for conventional x-ray examinations and is also a good indicator for when threshold doses for deterministic effects are reached in interventional x-ray procedures. Most modern x-ray equipment provides the operator with the total PKA from the examination or procedure. This PKA is either obtained from PKA measurements from a built-in KAP meter or calculated from exposure parameters. To get a reliable estimate of DRLs and the patient dose, it is essential that the PKA measurement is correct. Thus all environmental influences on the KAP meter should be taken into account. These influences can either be corrected for or included in the measurement uncertainty. These have to be considered both in the calibration of the KAP-meters, in the use of the KAP meters and in the determination of DRLs. A KAP meter is an electrometer and a plane parallel ion chamber with an active area of typical 15 cm X 15 cm. The KAP meter usually consist of three plastic plates (PMMA) which is coated with a conducting layer made of indium oxide doped with tin (In2O3:Sn). This coating is used due to its transparency to light. The air layers between the plates (sensitive volume) are open to the air. Thus the readings from the KAP meter have to be corrected for air pressure and temperature as for other ion chambers. It has been assumed that the humidity dependence of the KAP meter is so small that no correction has been necessary. This work will show that KAP meter with PMMA plastic plates coated with In2O3:Sn shows a humidity dependence so large that corrections should be considered. The measurements

  5. Trends and the determination of effective doses for standard X-ray procedures

    International Nuclear Information System (INIS)

    Trends in the entrance skin exposures (air kerma) for standard x-ray imaging procedures are reported for the Province of Manitoba, Canada. Average annual data per procedure using standard phantoms and standard ion chambers have been recorded since 1981. For example, chest air kerma (backscatter included) has decreased from 0.14 to 0.09 mGy. Confounding factors may negate the gains unless facility quality control programs are maintained. The data were obtained for a quality assurance and regulatory compliance program. Quoting such data for risk evaluation purposes lacks rigor hence a compartment model for organ apportioning, using organ absorbed doses and weighting factors, has been applied to determine effective dose per procedure. The effective doses for the standard procedures are presented, including the value of 0.027 mSv (1999) calculated for the effective dose in PA chest imaging. (author)

  6. ZZ VITAMIN-J/KERMA, Gas Production Cross-Sections, Neutron and Gamma Kerma in FOURACES Format

    International Nuclear Information System (INIS)

    1 - Description of program or function: Format: ANISN; Number of groups: 175 neutron plus 38 photon energy groups; Nuclides: H-1, D-2, T-3, Li-6, Li-7, Be-9, B-10, B-11, C, O-16, Al-27, Si, Ti, V, Cr, Mn-55, Fe, Ni, Cu, Zr, Nb-93, Mo, Ba-134, Ba-135, Ba-136, Ba-137, Ba-138, W-182, W-183, W-184, W-186, Pb, Bi-209, He-3, He-4, N-14, Mg, P-31, S, Ca, Co-59, In, Sn, Ta-181, Re Origin: EFF-1, DLC-99 (HUGO) data library; Weighting spectrum: Maxwellian plus 1/E plus fission spectrum plus fusion peak. Library of gas production cross sections, neutron kerma factors and photon kerma factors in FOURACES format according to GEFF-1 specifications. Kerma factors have been calculated for temperatures 300 K and 800 K. 2 - Method of solution: For the gas production cross sections, the lump reactions 203 and 207 included in EFF-1 had been assumed as the basic of the computation. The neutronics kerma factors have been calculated with the module KERMA of THEMIS. The photonic kerma factors have been calculated with the module GROUPG of THEMIS, starting from the DLC-99 (HUGO) data library of gamma interactions

  7. Determination and comparison of computed tomography quantities in standard beams using standard adult and pediatric phantoms

    International Nuclear Information System (INIS)

    The computed tomography (CT) is a segment of diagnostic radiology that uses higher radiation dose comparing to others fields of conventional radiology. In 2011, for decreasing the uncertainty in the diagnostic radiology beams dosimetry, the International Atomic Energy Agency (IAEA) published an implementation on the Technical Reports Series no. 457 from 2007, which is a code of practice recommending procedures for calibration and dosimetry in diagnostic radiology field. The objective of this study was to compare CT measurements on standards beams using adult and pediatric phantoms. The same procedure was used for two types of phantoms. Measurements were performed on the surface of the phantoms obtaining values of entrance surface air kerma (Ke). Measurements were taken from 100 to 150 kV (RQT 8, 9 and RQT 10), with the center of the simulators positioned at a distance of 100 cm from the focal spot. The values for the CT quantities air kerma index (in free air, CK, and in phantom, CPMMA,C / CPMMA,P) and air kerma length product (PKA) were found. The results were significant and the largest difference between the two phantoms was found for the radiation quality RQT 10. (author)

  8. Determination and comparison of computed tomography quantities in standard beams using standard adult and pediatric phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Elaine Wirney; Potiens, Maria da Penha A., E-mail: ewmartins@ipen.br, E-mail: mppalbu@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The computed tomography (CT) is a segment of diagnostic radiology that uses higher radiation dose comparing to others fields of conventional radiology. In 2011, for decreasing the uncertainty in the diagnostic radiology beams dosimetry, the International Atomic Energy Agency (IAEA) published an implementation on the Technical Reports Series no. 457 from 2007, which is a code of practice recommending procedures for calibration and dosimetry in diagnostic radiology field. The objective of this study was to compare CT measurements on standards beams using adult and pediatric phantoms. The same procedure was used for two types of phantoms. Measurements were performed on the surface of the phantoms obtaining values of entrance surface air kerma (K{sub e}). Measurements were taken from 100 to 150 kV (RQT 8, 9 and RQT 10), with the center of the simulators positioned at a distance of 100 cm from the focal spot. The values for the CT quantities air kerma index (in free air, C{sub K}, and in phantom, C{sub PMMA,C} / C{sub PMMA,P}) and air kerma length product (P{sub KA}) were found. The results were significant and the largest difference between the two phantoms was found for the radiation quality RQT 10. (author)

  9. Limitations of ambient air quality standards in evaluating indoor environments

    International Nuclear Information System (INIS)

    Analysis of the kinds of data used for the derivation of ambient air quality standards (AAQSs) for carbon monoxide and ozone shows that these values are based on the toxicology of the materials and thus are suitable for evaluating potential health effects of indoor environments, especially on the very young, the aged, and the infirm. A similar analysis shows that the AAQSs for suspended particulate matter, nitrogen dioxide, and sulfur dioxide are strictly empirical and that they should not be used for any but their first, intended purpose. The AAQSs for non-methane hydrocarbons are based on photochemical smog production, not injury of any kind, and have no utility for indoor environment evaluation

  10. 1990 INEL national emission standards for hazardous air pollutants

    International Nuclear Information System (INIS)

    The Environmental Protection Agency issued on December 15, 1989 final rules governing air emissions of radionuclides. Requirements concerning radionuclide emissions from Department of Energy Facilities are addressed under Title 40, Code Federal Regulations (CFR) 61, Subpart H, ''National Emission Standards for Emissions of Radionuclides other Than Radon From Department of Energy Facilities.'' Section 61.94 of the regulations require that each DOE facility submit on an annual basis a report documenting compliance with the Subpart H requirements. This report addresses the section 61.94 reporting requirements for operations at the Idaho National Engineering Laboratory (INEL) for calendar year 1990. The Idaho Operations Office of the Department of Energy is the primary contact concerning NESHAPs compliance at the INEL

  11. Information draft on the development of air standards for methanol

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    Methanol is a clear, colourless. very mobile liquid with a slightly alcoholic odour in pure form, but a repulsive pungent odour in crude form. Methanol is the raw material in the production of many gasoline additives, is used as a solvent or antifreeze in paint strippers, aerosol spray paints, wall paints, carburetor cleaners, and car windshield washer compounds. Methanol is one of the top pollutants by release quantities in Ontario, the highest release being generated by the pulp and paper industry. Other large emissions come from the plastics and synthetic resin industry. Total release to the air in Canada was 3,668 tonnes in 1996 and the top ten methanol emitting facilities were in Ontario. Methanol is readily absorbed through inhalation, ingestion and skin exposures. Once absorbed, it is oxidized to formaldehyde and then to formic acid. Common symptoms of exposure are visual disturbances, dizziness, nausea, vertigo, pain in the extremities, and headaches. No information was found as to the carcinogenicity of methanol to humans or animals. Current Ontario half-hour POI standard for methanol is 84,000 microgram/cubic meter and the 24-hour AAQC is 28,000 microgram/cubic meter. Both values were established more than 20 years ago. Review of relevant literature, summarized in this report, indicates that five US states have promulgated air quality guidelines or reference exposure levels for methanol, based on occupational exposure limits. The US Environmental Protection Agency is currently reviewing its reference concentration value for methanol. The World Health Organization and the Canadian federal government have not set air quality guidelines for methanol. 37 refs., 1 tab., appendix.

  12. Acidic precipitation: considerations for an air-quality standard

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L.S.; Hendrey, G.R.; Stensland, G.J.; Johnson, D.W.; Francis, A.J.

    1980-01-01

    Acidic precipitation, wet or frozen deposition with a hydrogen ion concentration greatern than 2.5 ..mu..eq l/sup -1/ is a significant air pollution problem in the United States. The chief anions accounting for the hydrogen ions in rainfall are nitrate and sulfate. Agricultural systems are more likely to derive net nutritional benefits from increasing inputs of acidic rain than are forest systems when soils alone are considered. Agricultural soils may benefit because of the high N and S requirements of agricultural plants. Detrimental effects to forest soils may result if atmospheric H/sup +/ inputs significantly add to or exceed H/sup +/ production by soils. Acidification of fresh waters of southern Scandinavia, southwestern Scotland, southeastern Canada, and northeastern United States is caused by acid deposition. Areas of these regions in which this acidification occurs have in common, highly acidic precipitation with volume weighted mean annual H/sup +/ concentrations of 25 ..mu..eq l/sup -1/ or higher and slow weathering granitic or precambrian bedrock with thin soils deficient in minerals which would provide buffer capacity. Biological effects of acidification of fresh waters are detectable below pH 6.0. As lake and stream pH levels decrease below pH. 6.0, many species of plants, invertebrates, and vertebrates are progressively eliminated. Generally, fisheries are impacted below pH 5.0 and are completely destroyed below pH 4.8. There are few studies that document effects of acidic precipitation on terrestrial vegetation to establish an air quality standard. It must be demonstrated that current levels of precipitation acidity alone significantly injure terrestrial vegetation. In terms of documented damanges, current research indicates that establishing a standard for precipitation for the volume weighted annual H/sup +/ concentration at 25 ..mu..eq l/sup -1/ may protect the most sensitive areas from permanent lake acidification.

  13. 77 FR 60341 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2012-10-03

    ... Source Performance Standards for Stationary Internal Combustion Engines'' (77 FR 33812). The June 7, 2012... Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion... Emission Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines...

  14. MACK, Fluence to Kerma Generator from ENDF/B

    International Nuclear Information System (INIS)

    1 - Nature of physical problem solved: The principal purpose of the program is in calculating pointwise neutron energy release parameters (fluence-to-kerma factors) at an arbitrary energy mesh from nuclear data in ENDF/B format (2). The kerma factors are of prime importance for calculating heating and dose rates in any nuclear system. The program processes all reactions significant to energy deposition. In addition, the program calculates energy group kerma factors and group cross sections by reactions (group constants not transfer matrices) averaged over an arbitrary input weighting function or any of the 'built-in' functions. When resonance data is available, the code calculates the contribution from the resolved and unresolved resonance parameters. The pointwise cross sections, pointwise kerma factors, energy group cross sections and energy group kerma factors can be printed, punched, and/or saved on tape for all reactions and the sum as selected by input. The pointwise kerma factors can be saved for later use (3) to generate group kerma factors for a different energy group structure or possibly for inclusion in the ENDF/B evaluation for the nuclide with the appropriate MT numbers in the 300's series (2). 2 - Method of solution: The expressions for the energy release per reaction are obtained from a solution of the kinematics of nuclear reactions. The anisotropy of elastic and inelastic scattering is considered. The contribution to energy deposition from radioactive decay of the residual nucleus can be added by reaction and is calculated using Fermi theory in the case of beta decay. In the resolved resonance region, MACK accepts either single or multi level Breit-Wigner parameters. Doppler broadening is performed at an arbitrary input temperature. The unresolved resonance treatment includes some shielding effects through a 1/sigma t weighting. The energy group kerma factors and cross sections are calculated by averaging the pointwise data over either a user

  15. PTRAC file utilization for calculation of free-air ionization chamber correction factors by MCNPX

    International Nuclear Information System (INIS)

    A free-air ionization chamber is used as a standard of photon air-kerma. Several correction factors are applied to the air-kerma value. Correction factors for electron loss: k(loss) and for additional ionization current caused by photon scatter: k(sc), photon fluorescence: k(fl), photon transmission through diaphragm edge k(dtr), and photon scatter from the surface of the diaphragm aperture k(dsc) were determined by the MCNPX code utilizing information stored in Particle Track (PTRAC) output files. Individual steps of the procedure are described and the calculated values of the correction factors are presented. The values are in agreement with the correction factors published in the literature for similar free-air chambers and low-energy photons. (authors)

  16. National Emission Standards for Hazardous Air Pollutants Calendar Year 2005

    International Nuclear Information System (INIS)

    The Nevada Test Site (NTS) is operated by the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO). From 1951 through 1992, the NTS was operated as the nation's site for nuclear weapons testing. The release of man-made radionuclides from the NTS as a result of testing activities has been monitored since the first decade of atmospheric testing. After 1962, when nuclear tests were conducted only underground, the radiation exposure to the public surrounding the NTS was greatly reduced. After the 1992 moratorium on nuclear testing, radiation monitoring on the NTS focused on detecting airborne radionuclides that are resuspended into the air (e.g., by winds, dust-devils) along with historically-contaminated soils on the NTS. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (40 Code of Federal Regulations 61 Subpart H) limits the release of radioactivity from a U. S. Department of Energy (DOE) facility (e.g., the NTS) to 10 millirem per year (mrem/yr) effective dose equivalent (EDE) to any member of the public. This is the dose limit established for someone living off of the NTS for inhaling radioactive particles that may be carried by wind off of the NTS. This limit assumes that members of the public surrounding the NTS may also inhale 'background levels' or radioactive particles unrelated to NTS activities that come from naturally-occurring elements in the environment (e.g., radon gas from the earth or natural building materials) or from other man-made sources (e.g., cigarette smoke). The U. S. Environmental Protection Agency (EPA) requires DOE facilities (e.g., the NTS) to demonstrate compliance with the NESHAP dose limit by annually estimating the dose to a hypothetical member of the public, referred to as the maximally exposed individual (MEI), or the member of the public who resides within an 80-kilometer (50-mile) radius

  17. Compliance plan for national emission standards for hazardous air pollutants

    International Nuclear Information System (INIS)

    The Portsmouth Gaseous Diffusion Plant (PORTS) is owned by the Department of Energy (DOE) and is managed by Martin Marietta Energy Systems, Inc. (MMES). The facility is located in sparsely populated, rural Pike County, Ohio, on a 16.2-km2 (6.3-mile2) site about 1.6 km (1 mile) east of the Scioto River Valley at an elevation approximately 36.6 m (120 ft) above the Scioto River floodplain. The terrain surrounding the plant, except for the Scioto River floodplain, consists of marginal farmland and densely forested hills. The principal site process is the separation of uranium isotopes through gaseous diffusion. Support operations include the feed and withdrawal of material from the primary process, treatment of water for both potable and cooling purposes, steam generation for heating purposes, decontamination of equipment removed from the process for maintenance or replacement, recovery of uranium from various waste materials, and treatment of industrial wastes generated on-site. PORTS will comply with National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations as a single facility as specified under ''Discussion of Source Categories, VI.A.4.d Definition of a Facility'' in Volume 54, No. 240 p. 51665 of the Federal Register. Continuous vent stack monitoring and dose modeling as specified in 40 CFR 61.93 of Subpart H will be used to demonstrate compliance with radionuclide NESHAP regulations. Ambient air monitoring stations near receptor sites and Health Physics monitoring in plant process buildings will be used to give assurance that unmonitored sources, or fugitive emission sources, are not emitting sufficient radionuclides to add a significant contribution to total plant emissions

  18. Preparation and determination of kerma for Iridium 192 sources of low dose rate for brachytherapy; Preparacion y determinacion del kerma de fuentes de iridio-192 de baja tasa de dosis para braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Tendilla, J.I.; Tovar M, V.; Mitsoura, E.; Aguilar H, F.; Alanis M, J. [Instituto Nacional de Investigaciones Nucleares, C.P. 52045-1, Salazar, Esrado de Mexico, D.F. (Mexico)

    2000-07-01

    The practice of Brachytherapy with Iridium-192 sources of low dose rate (0.4 - 0.8 Gy/h) is a technique used in the treatment of diverse illnesses. in this work the preparation, quality control and calibration are presented in terms of kerma in air of Iridium-192 using as target these recycled Iridium-Platinum wires. The targets were obtained as decayed sources of different radio therapeutical centers in the country and they were characterized by Scanning electron microscopy in order to determine their chemical composition. Subsequently it was developed an experimental design to establish the effect of neutron flux, geometrical array and irradiation time over the activity and percentage of the sources homogeneity. The homogeneity was determined by auto radiography and by Gamma spectroscopy. Once the optimal irradiation conditions were established, it is determined the apparent activity and kerma in air using a well type ionization chamber with traceability to a primary laboratory. Iridium-192 sources were obtained with an average homogeneity 96 %, apparent activity 282.129 {+-} 0.531 M Bq and kerma in air 0.03200 {+-} 0.00006 m Gy m/h A. (Author)

  19. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  20. The role of constitution's standards as the integration part of forming of Ukrainian Air law system

    OpenAIRE

    Шереметьєва, Ольга Юріївна; Інститут повітряного і космічного права та масових комунікацій, Національний авіаційний університет

    2015-01-01

    The role and meaning of constitution's standards as the integration part of forming of Air law system are investigatedat the article and also the status of Ukrainian legislation about the air area using.

  1. Comparison of TLD air kerma measurements in mammography

    International Nuclear Information System (INIS)

    The mammography examination is usually targeted at asymptomatic women so the narrow balance between benefit and undesirable effects is important. During the past few decades there have been significant advances in the equipment used for mammography. Even when the latest equipment and imaging systems are used, there is considerable variation from centre-to-centre in the choice of imaging parameters and techniques. There may be quite large differences in image quality and breast dose among the centres. A Co-ordinated Research Programme on 'Image quality and patient dose optimization in mammography in Eastern European Countries' was conducted by the IAEA, aiming at defining a methodology for the implementation of a quality assurance (QA) programme in mammography and at exercising the assessment of image quality and patient doses in a sample of hospitals in East European countries. Selected mammography clinics from Czech Republic, Hungary, Poland, Romania and Slovakia participate in the project. The teams consisted of experienced clinicians and physicists. They were supported by a group of experts (clinicians and medical physicists) from France, Italy and Spain. As an outcome of the project, improvements in these indicators (image quality and patient dose) after the implementation of the QA programme are expected. A comparison of dosimetry systems has been organized to assure that dosimetry measurements done in the frame of the project are comparable and traceable to the international measurement system. All five East European countries plus Spain took part in the exercise. The thermoluminescent (TL) method was selected for the comparison

  2. New ICRU quantities for the environmental and individual monitoring. Standardization of individual dosemeters by using external beams of photon radiation

    International Nuclear Information System (INIS)

    The quantities introduced by ICRU for the radiological monitoring are commented, specially those implied in individual protection against external photons. A procedure is proposed in order to standardize the individual dosemeters by using the kerma in air references of CIEMAT-JEN. The reference radiation beams are described in connection with ISO standards. Provisional values are selected for the appropriate conversion and correction factors. (Author) 23 refs

  3. Characterization of a free-air ionization chamber in direct X-ray beams as used in mammography; Caracterizacao de uma camara de ionizacao de ar-livre em feixes diretos de raios X utilizados em mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Mateus Hilario de

    2014-08-01

    At this work stability and characterization tests were undertaken on a Victoreen free-air ionization chamber, model 481. The tests were realized using direct X-ray beams as a contribution for its establishment as a primary standard system of the quantity air kerma. The characterization tests were: saturation curve, ion collection efficiency, polarity effect, response linearity with the air kerma rate and response linearity with the chamber volume variation. The ion collection efficiency allowed the determination of the ion recombination factor. Most of the test results showed agreement with the limits established by international standards. Furthermore, the air attenuation factors for the mammography beams with aluminum and molybdenum filters were obtained. The factors for photon transmission and scattering at the diaphragm edges were also determined for mammography beams with aluminum filter and for the standard beam with molybdenum filter. (author)

  4. Fundamental relationships between linear energy transfer, absorbed dose, kerma, and exposure. Application to changes of mediums

    International Nuclear Information System (INIS)

    After briefly defining the quantities used in dosimetry and presenting them with a view to their simple adaptation to health physics problems, the authors establish simple mathematical relationships to express the absorbed dose, kerma and exposure in the case of electrons and photons, and also relationships between these various quantities considered in air. They then proceed to study the variations in these quantities at the interface between the air and the soft tissues of the organism and in depth in the tissues. They give the numerical values of the discontinuities liable to appear at the interface and the values obtained, relative to air, after electronic equilibrium is established in depth in the tissues. An example of application to dosimetry is also given in the case of an aluminium-walled ionization chamber. To conclude, the conditions to be fulfilled in order to make a direct measurement of the absorbed dose in the tissues are presented and discussed. (authors)

  5. Characterization of a free air ionization chamber for low energies

    International Nuclear Information System (INIS)

    Free air ionization chambers are used by most primary metrology laboratories as primary standards of the quantities air kerma and exposure in X-ray beams. The free air ionization chamber for low energies of the Calibration Laboratory (LCI) of IPEN showed in a characterization test a problem in the set responsible for the variation of its sensitive volume. After a modification in the support of the micrometers used for the movement of the internal cylinder and the establishment of a new alignment system protocol, the tests were redone. The objective of this work was to present the results obtained in the new condition. (author)

  6. A proposed risk management framework for the air standard setting process in Ontario : a discussion paper

    International Nuclear Information System (INIS)

    This paper described the implementation of Ontario's new or revised air quality standards relating to Ontario Regulation 346 under the Environmental Protection Act. With clean air as a high priority, the Ontario Ministry of the Environment is striving to find solutions to problems that pose the greatest risk to human health and the environment. Their most recent initiatives in the development of better air quality standards have included the use of the latest scientific information to develop protective, effects-based air standards and the development of a risk management framework to implement the new standards while allowing for time, technology and economic issues to be considered. An update of Regulation 346 air dispersion models ensures that the latest scientific tools are being used to asses compliance with air standards. The phasing out of the existing air dispersion models means that they will be replaced by a series of models from the United States Environmental Protection Agency (in particular AERMOD and ISC-PRIME). This will promote the use of the most modern scientific tools available to assess compliance with air quality standards. The major advantage of introducing new air dispersion models is the ability to use effects-based standards with appropriate averaging times to assess compliance. This makes it possible to better assess the health and environmental impacts from air emissions. 3 tabs., 3 figs

  7. The role of Health Impact Assessment in the setting of air quality standards: An Australian perspective

    International Nuclear Information System (INIS)

    The approaches used for setting or reviewing air quality standards vary from country to country. The purpose of this research was to consider the potential to improve decision-making through integration of HIA into the processes to review and set air quality standards used in Australia. To assess the value of HIA in this policy process, its strengths and weaknesses were evaluated aligned with review of international processes for setting air quality standards. Air quality standard setting programmes elsewhere have either used HIA or have amalgamated and incorporated factors normally found within HIA frameworks. They clearly demonstrate the value of a formalised HIA process for setting air quality standards in Australia. The following elements should be taken into consideration when using HIA in standard setting. (a) The adequacy of a mainly technical approach in current standard setting procedures to consider social determinants of health. (b) The importance of risk assessment criteria and information within the HIA process. The assessment of risk should consider equity, the distribution of variations in air quality in different locations and the potential impacts on health. (c) The uncertainties in extrapolating evidence from one population to another or to subpopulations, especially the more vulnerable, due to differing environmental factors and population variables. (d) The significance of communication with all potential stakeholders on issues associated with the management of air quality. In Australia there is also an opportunity for HIA to be used in conjunction with the NEPM to develop local air quality standard measures. The outcomes of this research indicated that the use of HIA for air quality standard setting at the national and local levels would prove advantageous. -- Highlights: • Health Impact Assessment framework has been applied to a policy development process. • HIA process was evaluated for application in air quality standard setting.

  8. The role of Health Impact Assessment in the setting of air quality standards: An Australian perspective

    Energy Technology Data Exchange (ETDEWEB)

    Spickett, Jeffery, E-mail: J.Spickett@curtin.edu.au [WHO Collaborating Centre for Environmental Health Impact Assessment (Australia); Faculty of Health Sciences, School of Public Health, Curtin University, Perth, Western Australia (Australia); Katscherian, Dianne [WHO Collaborating Centre for Environmental Health Impact Assessment (Australia); Faculty of Health Sciences, School of Public Health, Curtin University, Perth, Western Australia (Australia); Harris, Patrick [CHETRE — UNSW Research Centre for Primary Health Care and Equity, University of New South Wales (Australia)

    2013-11-15

    The approaches used for setting or reviewing air quality standards vary from country to country. The purpose of this research was to consider the potential to improve decision-making through integration of HIA into the processes to review and set air quality standards used in Australia. To assess the value of HIA in this policy process, its strengths and weaknesses were evaluated aligned with review of international processes for setting air quality standards. Air quality standard setting programmes elsewhere have either used HIA or have amalgamated and incorporated factors normally found within HIA frameworks. They clearly demonstrate the value of a formalised HIA process for setting air quality standards in Australia. The following elements should be taken into consideration when using HIA in standard setting. (a) The adequacy of a mainly technical approach in current standard setting procedures to consider social determinants of health. (b) The importance of risk assessment criteria and information within the HIA process. The assessment of risk should consider equity, the distribution of variations in air quality in different locations and the potential impacts on health. (c) The uncertainties in extrapolating evidence from one population to another or to subpopulations, especially the more vulnerable, due to differing environmental factors and population variables. (d) The significance of communication with all potential stakeholders on issues associated with the management of air quality. In Australia there is also an opportunity for HIA to be used in conjunction with the NEPM to develop local air quality standard measures. The outcomes of this research indicated that the use of HIA for air quality standard setting at the national and local levels would prove advantageous. -- Highlights: • Health Impact Assessment framework has been applied to a policy development process. • HIA process was evaluated for application in air quality standard setting.

  9. Standards for securing adequate indoor air quality across Europe

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Carrer, P.; de Oliveira Fernandes, E.;

    2013-01-01

    human bioeffluents and is determined mainly considering the metabolic CO2 production. It is only applicable if all other pollutants meet WHO guidelines for ambient and indoor air quality. If they do not meet these guidelines after applying source control and when air used for ventilation is clean health...

  10. Standards for securing adequate indoor air quality across Europe

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Carrer, P.; de Oliveira Fernandes, E.; Hanninen, O.; Popov, T.

    Background: Inadequate IAQ causes a loss of 2 million healthy life years annually in the EU. Europeans spend typically over 85–90% of their time indoors and the main factors that affect negatively the characteristics of the air they breathe are outdoor air used to ventilate indoor spaces and indoor...... studies improperly characterised exposures and because of their inhomogenity. Risk modelling simulations of different strategies resulting in reduction of DALYs suggested that healthbased ventilation requirements should be combined with source control strategies and if necessary cleaning of outdoor air in...... human bioeffluents and is determined mainly considering the metabolic CO2 production. It is only applicable if all other pollutants meet WHO guidelines for ambient and indoor air quality. If they do not meet these guidelines after applying source control and when air used for ventilation is clean health...

  11. 78 FR 3085 - National Ambient Air Quality Standards for Particulate Matter

    Science.gov (United States)

    2013-01-15

    ... the original air quality criteria document (DHEW, 1969; 36 FR 8186, April 30, 1971). The reference... review of the air quality criteria and NAAQS for PM (62 FR 55201, October 23, 1997). After CASAC and... the 24-hour PM 2.5 standard at a level of 35 g/m\\3\\. The EPA is revising the Air Quality Index...

  12. 76 FR 74708 - National Emission Standards for Hazardous Air Pollutants for Source Categories

    Science.gov (United States)

    2011-12-01

    ... AGENCY 40 CFR Part 63 National Emission Standards for Hazardous Air Pollutants for Source Categories CFR... means mineral wool to which a hazardous air pollutant-based binder (containing such hazardous air pollutants as phenol or formaldehyde) has been applied. CO means, for the purposes of this subpart,...

  13. 75 FR 6473 - Primary National Ambient Air Quality Standards for Nitrogen Dioxide

    Science.gov (United States)

    2010-02-09

    ... parts per million (ppm) (53 ppb), annual average (36 FR 8186). EPA completed reviews of the air quality criteria and NO 2 standards in 1985 and 1996 with decisions to retain the standard (50 FR 25532, June 19, 1985; 61 FR 52852, October 8, 1996). EPA initiated the current review of the air quality criteria...

  14. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  15. 77 FR 2677 - National Emission Standards for Hazardous Air Pollutants: Primary Aluminum Reduction Plants...

    Science.gov (United States)

    2012-01-19

    ... Standards for Hazardous Air Pollutants: Primary Aluminum Reduction Plants'' is being extended for 12 days. DATES: Comments. The public comment period for the proposed rule published December 6, 2011, (76 FR... AGENCY 40 CFR Part 63 RIN 2060-AQ-92 National Emission Standards for Hazardous Air Pollutants:...

  16. 76 FR 78872 - National Emission Standards for Hazardous Air Pollutants for Wool Fiberglass Manufacturing

    Science.gov (United States)

    2011-12-20

    ... AGENCY 40 CFR Part 63 RIN 2060-AQ90 National Emission Standards for Hazardous Air Pollutants for Wool... Pollutants: Mineral Wool Production and Wool Fiberglass Manufacturing.'' The EPA was asked to hold a public... docket for the proposed rule, ``National Emission Standards for Hazardous Air Pollutants: Wool...

  17. 77 FR 41146 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories...

    Science.gov (United States)

    2012-07-12

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 63 Delegation of National Emission Standards for Hazardous Air Pollutants for Source... delegation of specific national emission standards for hazardous air pollutants (NESHAP) to the Gila...

  18. 76 FR 38591 - National Emission Standards for Hazardous Air Pollutants: Secondary Lead Smelting; Extension of...

    Science.gov (United States)

    2011-07-01

    ... the National Emissions Standards for Hazardous Air Pollutants for Secondary Lead Smelting (76 FR 29032... Standards for Hazardous Air Pollutants: Secondary Lead Smelting, was published May 19, 2011 (76 FR 29032... current rule. DATES: Comments on the proposed rule published May 19, 2011 (76 FR 29032) must be...

  19. Project, construction and characterization of ionization chambers for use as standard systems in X and gamma radiation beams

    International Nuclear Information System (INIS)

    Ionization chambers present some advantages in relation to other dosimeters: easiness of handling, low energy dependence and high precision. The advantages associated to ionization chambers and the large number of diagnostic radiology exams and therapeutic treatments motivated the development of this PhD program. In this project ionization chambers were developed and characterized to be applied in diagnostic radiology and therapy beam dosimetry, with high precision and performance, in compliance with international recommendations. They were assembled in a simple way, utilizing low-cost national materials, so they can be reproduced and applied at calibration laboratories. The project of these ionization chambers presents some differences in relation to commercial ionization chambers, as the materials utilized and geometrical arrangements. Besides the development of the ionization chambers to be utilized in standard X-ray beam dosimetry as work standard systems, two graphite parallel-plate ionization chambers were developed and characterized to be applied as reference standard systems for determining the air kerma rates of gamma radiation sources. Comparing the air kerma rates determined with the reference standard of the Calibration Laboratory of IPEN, a Farmer ionization chamber, with the values of the air kerma rates obtained with the graphite ionization chambers, the maximum differences obtained were only 1.7% and 1.2% for the G1 and G2 graphite ionization chambers, respectively. Moreover, these ionization chambers presented correction factors close to 1.000, which is ideal for an ionization chamber be characterized as a reference standard system. (author)

  20. Development of a calibration methodology and tests of kerma area product meters; Desenvolvimento de uma metodologia de calibracao e testes de medidores de produto Kerma-Area

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Nathalia Almeida

    2013-07-01

    The quantity kerma area product (PKA) is important to establish reference levels in diagnostic radiology exams. This quantity can be obtained using a PKA meter. The use of such meters is essential to evaluate the radiation dose in radiological procedures and is a good indicator to make sure that the dose limit to the patient's skin doesn't exceed. Sometimes, these meters come fixed to X radiation equipment, which makes its calibration difficult. In this work, it was developed a methodology for calibration of PKA meters. The instrument used for this purpose was the Patient Dose Calibrator (PDC). It was developed to be used as a reference to check the calibration of PKA and air kerma meters that are used for dosimetry in patients and to verify the consistency and behavior of systems of automatic exposure control. Because it is a new equipment, which, in Brazil, is not yet used as reference equipment for calibration, it was also performed the quality control of this equipment with characterization tests, the calibration and an evaluation of the energy dependence. After the tests, it was proved that the PDC can be used as a reference instrument and that the calibration must be performed in situ, so that the characteristics of each X-ray equipment, where the PKA meters are used, are considered. The calibration was then performed with portable PKA meters and in an interventional radiology equipment that has a PKA meter fixed. The results were good and it was proved the need for calibration of these meters and the importance of in situ calibration with a reference meter. (author)

  1. National emmission standards for hazardous air pollutants, Submittal -- 1993

    Energy Technology Data Exchange (ETDEWEB)

    Black, S.C.

    1994-06-01

    This report discusses the effects on the environment caused by weapons testing at the Nevada Test Site. Topics include: emission of radionuclides into the air, atmospheric pumping of noble gases, tunnel operations, drillbacks, laboratories, radioactive waste management site, and plutonium contamination of surface areas.

  2. Heating, Air-Conditioning, and Refrigeration Technician. National Skill Standards.

    Science.gov (United States)

    Vocational Technical Education Consortium of States, Decatur, GA.

    This guide contains information on the knowledge and skills identified by industry as essential to the job performance of heating, air-conditioning, and refrigeration technicians. It is intended to assist training providers in public and private institutions, as well as in industry, to develop and implement training that will provide workers with…

  3. 76 FR 46083 - Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur

    Science.gov (United States)

    2011-08-01

    ... million (ppm) as an annual average (36 FR 8186). In 1982, EPA published Air Quality Criteria Document for... received on the proposal (61 FR 52852; October 8, 1996). While the primary NO 2 standard was revised in... NAAQS for SO 2 in April 1971 (36 FR 8186). The secondary standards included a standard set at 0.02...

  4. Absorbed dose evaluation by SISCODES code, kerma and fluence deviations

    International Nuclear Information System (INIS)

    Radiotherapy is a common treatment of cancer. Radiotherapy exposes the patient to a radiation field, producing ionization, and absorbed dose. A precise dose calculation and the ability to execute the irradiation on the patient are necessary in order to avoid serious injuries on the surrounding health tissue, thus, the maximum acceptable absorbed dose error from the prescribed and applied is about 5%. The doses on radiotherapy are usually calculated by superimposition experimental dose profile, namely PDP, which is experimentally measured in a water simulator. Moreover, the radiation interaction with human body tissues depends on the chemical composition and the tissue density, which means the anthropomorphism and anthropometric of the human being. This paper evaluates the deviation of calculated value of kerma, induced by human body heterogeneities. To do this job two thorax voxel models created on SISCODES (one filled with various tissues other filled with water) were applied. The result of simulations permits two different comparisons. One is the ratio between tissues kermas and water kerma. Another is the ratio between human phantom fluence, where exists radiation scatter and reflection, and water phantom fluence. The reconstructed pictures of studied regions showing the calculated ratios, and graphs of the ratios versus energy of each tissue are shown. The dose ratio deviations obtained are, in some situations, larger than the acceptable 5% point out serious miscalculation of doses for some spatial regions on the human body. (author)

  5. Controlled clinical studies of air pollutant exposure: evaluating scientific information in relation to air quality standards.

    OpenAIRE

    Hackney, J D; Linn, W S

    1983-01-01

    In controlled clinical studies, volunteers are deliberately exposed to specific air pollutants under conditions simulating ambient exposures, and health-related responses are documented. Studies of the health risks of air pollution need to be scientifically rigorous and clearly relevant to "real-world" pollution exposures. Their results should be confirmed by independent replication if they are to be used as a basis for air quality regulations. Well-designed controlled clinical studies readil...

  6. National Emission Standards for Hazardous Air Pollutants Calendar Year 2006

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Technical Services

    2007-06-01

    The Nevada Test Site (NTS) is operated by the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO). From 1951 through 1992, the NTS was operated as the nation's site for nuclear weapons testing. The release of man-made radionuclides from the NTS as a result of testing activities has been monitored since the first decade of atmospheric testing. After 1962, when nuclear tests were conducted only underground, the radiation exposure to the public surrounding the NTS was greatly reduced. After the 1992 moratorium on nuclear testing, radiation monitoring on the NTS focused on detecting airborne radionuclides which come from historically-contaminated soils resuspended into the air (e.g., by winds) and tritium-contaminated soil moisture emitted to the air from soils through evapotranspiration.

  7. The 1997 determination of the Australian standards of exposure and absorbed dose at {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Huntley, R.B.; Boas, J.F. [Australian Radiation Laboratory, Yallambie, VIC (Australia); Van der Gaast, H. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1998-05-01

    The arrangements for the maintenance of the Australian standards for {sup 60}Co are described in detail. The primary standards are a graphite cavity chamber for exposure/air kerma and a graphite calorimeter for absorbed dose. These secondary standards are described and their responses in corresponding {sup 90}Sr reference sources are reported. Accurate ratios between the Australian Radiation Laboratory (ARL) and Australian Nuclear Science and Technology (ANSTO) {sup 90}Sr reference sources are derived for use in future calibrations. The value of 28.8 years for the half-life of {sup 90}Sr is confirmed. The usefulness of {sup 90}Sr reference source measurements in quality assurance is discussed. The charge sensitivity and linearity of the ANSTO electrometers are reported by two different methods and are compared with previous results. Calibration factors for all the secondary standard ionization chambers are given, in terms of exposure, air kerma and absorbed dose to water. Calibration factors are also given for most of the chambers in terms of absorbed dose to graphite. The methods of deriving the calibration factors are explained in detail, including all the corrections applied to both the primary and secondary standard measurements. Three alternative methods of deriving the absorbed dose to water calibration factors are compared. The reported calibration factors are compared with previous results. Changes in the Australian units of exposure, air kerma and absorbed dose to graphite and water are derived from changes in the corresponding calibration factors. The Australian units of exposure and air kerma have not changed significantly since 1990. The Australian unit of absorbed dose to graphite is now 1.1 % smaller than in 1993 and 1.3 % smaller than in 1990. The Australian unit of absorbed dose to water is now 1.4 % smaller than in 1993, but is only 0.9 % smaller than in 1990. Comparisons of the Australian standards of exposure/air kerma and absorbed dose with

  8. The 1997 determination of the Australian standards of exposure and absorbed dose at 60Co

    International Nuclear Information System (INIS)

    The arrangements for the maintenance of the Australian standards for 60Co are described in detail. The primary standards are a graphite cavity chamber for exposure/air kerma and a graphite calorimeter for absorbed dose. These secondary standards are described and their responses in corresponding 90Sr reference sources are reported. Accurate ratios between the Australian Radiation Laboratory (ARL) and Australian Nuclear Science and Technology (ANSTO) 90Sr reference sources are derived for use in future calibrations. The value of 28.8 years for the half-life of 90Sr is confirmed. The usefulness of 90Sr reference source measurements in quality assurance is discussed. The charge sensitivity and linearity of the ANSTO electrometers are reported by two different methods and are compared with previous results. Calibration factors for all the secondary standard ionization chambers are given, in terms of exposure, air kerma and absorbed dose to water. Calibration factors are also given for most of the chambers in terms of absorbed dose to graphite. The methods of deriving the calibration factors are explained in detail, including all the corrections applied to both the primary and secondary standard measurements. Three alternative methods of deriving the absorbed dose to water calibration factors are compared. The reported calibration factors are compared with previous results. Changes in the Australian units of exposure, air kerma and absorbed dose to graphite and water are derived from changes in the corresponding calibration factors. The Australian units of exposure and air kerma have not changed significantly since 1990. The Australian unit of absorbed dose to graphite is now 1.1 % smaller than in 1993 and 1.3 % smaller than in 1990. The Australian unit of absorbed dose to water is now 1.4 % smaller than in 1993, but is only 0.9 % smaller than in 1990. Comparisons of the Australian standards of exposure/air kerma and absorbed dose with those of the Bureau International

  9. Review of kerma-area product and total energy incident on patients in radiography, mammography and CT

    International Nuclear Information System (INIS)

    This study estimated the energy incident on patients in radiography, mammography and CT using data related to X-ray beam quantity and quality. The total X-ray beam quantity is the average Air Kerma multiplied by the X-ray beam area and expressed as the Kerma-Area Product (Gy cm-2). The X-ray beam quality primarily depends on the target material (and anode angle), X-ray voltage (and ripple) as well as X-ray beam filtration. For any X-ray spectra, dividing total energy (fluence x mean energy) by the X-ray beam Kerma-Area Product yields the energy per Kerma-Area Product value (ε/KAP). Published data on X-ray spectra characteristics and energy fluence per Air Kerma conversion factors were used to determine 1/KAP factors. In radiography, ε/KAP increased from 6 mJ Gy-1 cm-2 at the lowest X-ray tube voltage (50 kV) to 25 mJ Gy-1 cm-2 at the highest X-ray tube voltage (140 kV). 1/KAP values ranged between 1 and 5 mJ Gy-1 cm-2 in mammography and between 24 and 42 mJ Gy-1 cm-2 in CT. Changes in waveform ripple resulted in variations in ε/KAP of up to 15 %, similar to the effect of changes resulting in the choice of anode angle. For monoenergetic X-ray photons, there was a sigmoidal-type increase in ε/KAP from 2 mJ Gy-1 cm-2 at 20 keV to 42 mJ Gy-1 cm-2 at 80 keV. However, between 80 and 150 keV, the ε/KAP shows variations with changing photon energy of <10 %. Taking the average spectrum energy to consist of monoenergetic X rays generally overestimates the true value of ε/KAP. This study illustrated that the energy incident on a patient in any area of radiological imaging can be estimated from the total X-ray beam intensity (KAP) when X-ray beam quality is taken into account. Energy incident on the patient can be used to estimate the energy absorbed by the patient and the corresponding patient effective dose. (authors)

  10. New ICRU quantities for the environmental and individual monitoring. Standardization of individual dosemeters by using external beams of photon radiation; Nuevas magnitudes ICRU para la vigilancia radiologica ambiental e individual. Calibracion de dosimetros personales usando haces externos de fotones

    Energy Technology Data Exchange (ETDEWEB)

    Brosed, A.; Delgado, A.; Granados, C. E.

    1987-07-01

    The quantities introduced by ICRU for the radiological monitoring are commented, specially those implied in individual protection against external photons. A procedure is proposed in order to standardize the individual dosemeters by using the kerma in air references of CIEMAT-JEN. The reference radiation beams are described in connection with ISO standards. Provisional values are selected for the appropriate conversion and correction factors. (Author) 23 refs.

  11. 75 FR 65594 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Particulate Matter Standards

    Science.gov (United States)

    2010-10-26

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Ohio; Particulate... have been necessary to attain and maintain the 2006 National Ambient Air Quality Standards for PM...

  12. 76 FR 80727 - Flexible Implementation of the Mercury and Air Toxics Standards Rule

    Science.gov (United States)

    2011-12-27

    ... 21, 2011 [FR Doc. 2011-33337 Filed 12-23-11; 8:45 am] Billing code 6560-50-P ... Documents#0;#0; ] Memorandum of December 21, 2011 Flexible Implementation of the Mercury and Air Toxics... the Environmental Protection Agency (EPA), of the final Mercury and Air Toxics Standards rule...

  13. 76 FR 14636 - National Emission Standards for Hazardous Air Pollutants: Primary Lead Smelting

    Science.gov (United States)

    2011-03-17

    ... Air Pollutants for Primary Lead Smelting (76 FR 9410). The EPA is extending the deadline for written... Pollutants: Primary Lead Smelting, was published February 17, 2011 (76 FR 9410). EPA has established the... AGENCY 40 CFR Part 63 RIN 2060-AQ42 National Emission Standards for Hazardous Air Pollutants:...

  14. 76 FR 21692 - National Emission Standards for Hazardous Air Pollutants: Primary Lead Smelting

    Science.gov (United States)

    2011-04-18

    ... Air Pollutants for Primary Lead Smelting (76 FR 9410). The EPA is extending the deadline for written... Pollutants: Primary Lead Smelting, was published February 17, 2011 (76 FR 9410). EPA has established the... AGENCY 40 CFR Part 63 RIN 2060-AQ43 National Emission Standards for Hazardous Air Pollutants:...

  15. 77 FR 11476 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories; Nevada

    Science.gov (United States)

    2012-02-27

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 63 Delegation of National Emission Standards for Hazardous Air Pollutants for Source... for hazardous air pollutants (NESHAP) to the Nevada Division of Environmental Protection on October...

  16. New brachytherapy standards paradigm shift

    International Nuclear Information System (INIS)

    Full text: The absorbed dose rate to water at short distances (1 cm typically) in water, is the quantity of interest for dosimetry in radiotherapy treatments. Moreover, the dose imparted to cancer patients must be known within a narrow band of uncertainty to avoid either damage to the healthy tissue resulting from exceeding international accepted tolerance levels or lack of tumor control due to a low dose delivered to the target volume. The goal for the uncertainty of the dose delivered to the target volume would be around 5% (at the level of one standard deviation), to assure the effectiveness of the radiotherapy treatment. This also takes into account the uncertainties in dose calculation algorithms. In current brachytherapy (BT) treatments, the procedures to determine the absorbed dose imparted to the patient are not based on absorbed dose standards, but are based on measurements traceable to air kerma standards. In fact, the recommended quantity for the calibration of BT gamma ray sources is the reference air kerma rate, KR, defined as the kerma rate to air, in air, at the reference distance of 1 m from the radioactive source, corrected for air attenuation and scattering. The absorbed dose around a BT source is currently calculated by applying the formalism of the international AAPM Task Group 43 protocol and its update. This protocol is based on the air kerma strength, SK, a quantity that is numerically equivalent to KR, at a distance of 1 m from the source. The dose rate constant Λ converts the air-kerma strength SK to the absorbed dose rate to water, D.(r0,θ0), in water at the reference position: D.(r0,θ0) = SK·A (1). Recently, a lower limit of 2,50 % was obtained for the estimated overall uncertainty (at the level of one standard deviation) on measurements of D.(r0,θ0) due to a HDR 192I BT source based on equation (1). However, in most cases the determination of 5K is typically affected by an uncertainty within 0,8 % (at the level of one standard

  17. 77 FR 51798 - First Draft Documents Related to the Review of the National Ambient Air Quality Standards for Ozone

    Science.gov (United States)

    2012-08-27

    ... AGENCY First Draft Documents Related to the Review of the National Ambient Air Quality Standards for... of the Ozone National Ambient Air Quality Standards: First External Review Draft. The Agency is... titled, Policy Assessment for the Review of the Ozone National Ambient Air Quality Standards:...

  18. Environmental Monitoring, Air Quality - MO 2011 Air Quality Standards Nonattainment Areas (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — The St. Louis air quality nonattainment areas geospatial data layer contains regions representing the geographic extent of areas that are estimated to be out of...

  19. Laboratory Evaluation of Air Flow Measurement Methods for Residential HVAC Returns for New Instrument Standards

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Stratton, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-08-01

    This project improved the accuracy of air flow measurements used in commissioning California heating and air conditioning systems in Title 24 (Building and Appliance Efficiency Standards), thereby improving system performance and efficiency of California residences. The research team at Lawrence Berkeley National Laboratory addressed the issue that typical tools used by contractors in the field to test air flows may not be accurate enough to measure return flows used in Title 24 applications. The team developed guidance on performance of current diagnostics as well as a draft test method for use in future evaluations. The study team prepared a draft test method through ASTM International to determine the uncertainty of air flow measurements at residential heating ventilation and air conditioning returns and other terminals. This test method, when finalized, can be used by the Energy Commission and other entities to specify required accuracy of measurement devices used to show compliance with standards.

  20. National Emission Standards for Hazardous Air Pollutants Submittal - 1998; TOPICAL

    International Nuclear Information System (INIS)

    The Nevada Test Site (NTS) is operated by the U.S. Department of Energy Nevada Operations Office (DOE/NV) as the site for nuclear weapons testing, now limited to readiness activities and experiments in support of the national Stockpile Stewardship Management Program. It is located in Nye County, Nevada, with the southeast corner about 105 km (65 mi) northwest of Las Vegas, Nevada. The NTS covers about 3,500 km2 (1,350 mi2), an area larger than Rhode Island. Its size is about 46 to 56 km (28 to 35 mi) east to west and from 64 to 88 km (40 to 55 mi)north to south. The NTS is surrounded, except on the south side, by public exclusion areas (Nellis Air Force Range) that provide another 24 to 104 km (15 to 65 mi) between the NTS and public lands. The NTS is characterized by desert valley and Great Basin mountain topography, with a climate, flora, and fauna typical of the southwest deserts. Surface waters are scarce on the NTS and there is great depth to slow-moving groundwater

  1. 77 FR 37361 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2012-06-21

    ....gov/fdsys/pkg/FR-2012-06-07/pdf/2012-13193.pdf and also in the docket identified below. The public... Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion... proposed rule, ``National Emission Standards for Hazardous Air Pollutants for Reciprocating...

  2. 78 FR 14457 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2013-03-06

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 60 and 63 RIN 2060-AQ58 National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal...

  3. 75 FR 31895 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial...

    Science.gov (United States)

    2010-06-04

    ...-AM44 National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial... standards today pursuant to CAA section 129 for commercial and industrial solid waste incineration units. In... industrial solid waste material at all--subject to the four statutory exceptions identified .'' NRDC v....

  4. 76 FR 8157 - National Ambient Air Quality Standards for Carbon Monoxide

    Science.gov (United States)

    2011-02-11

    ... be effectively mitigated by setting more stringent ambient air quality standards (59 FR 38914). Apart... average, neither to be exceeded more than once per year (36 FR 8186). In the 1971 decision, the... criteria and standards for CO (50 FR 37484). In that review, EPA updated the scientific criteria upon...

  5. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). Link to an... to or greater than 0.005 ppm shall be rounded up). (c) Sulfur oxides shall be measured in the...

  6. ZZ RFL-2-DTF, Group Constant Library of Reaction Cross-Section, Gas Production, Kerma, DPA

    International Nuclear Information System (INIS)

    adopted from the MACKLIB-IV library. The list of the included materials is given in one separate file. The position of the reactions in the RFL-2 matrix are given in the ZZRFL2.POS file. Source libraries GEFF-2: This P5 library for fusion neutronics calculations is based upon the 175 neutron, 42 photon VITAMIN-J group structure with the standard weighting function: Maxwellian (at the temperature to which the material is referenced) + 1/E + fission spectrum + 1/E + fusion peak + 1/E. It includes 93 materials - almost all from EFF-2 basic data; but Ag-107, Ag-109, natural Cd, the 6 Hf isotopes and the 4 W isotopes have been taken from JEF-2.2 - at 3 temperatures and 6 dilution values; 10 thermal groups are provided below 3 eV. Neutron cross sections and diffusion matrices, photon and gas production, kerma and DPA are given. GEPDL: GEPDL is a 42 group photon interaction P8 library based upon EPDL-90 to be used in conjunction with GEFF-2 for preparing neutron + photon coupled libraries by means of codes such as MATXSR - to produce data for TRANSX - or SMILER - an AMPX-77 module to produce AMPX Master Libraries from GENDF structured data. DECNET: DECNET is a library for fusion damage computations of 175 neutron +42 photon VITAMIN-J energy group with the standard weighting function: Maxwellian (at the temperature to which the material is referenced) + 1/E + fission spectrum + 1/E + fusion peak + 1/E; it includes neutron kerma and gamma-ray production data from radioactive nuclei at 3 temperatures with the same materials of ZZ-GEFF-2-GENDF (see below) from 1-H-1 to Bi-209, mostly taken from EFF-2 with some nuclides from JEF-2.2 - Ag-107, Ag-109, Cd, the 6 Hf isotopes and the 4 W isotopes; however the list of the materials disagrees with that of GEFF-2 in that all elemental nuclides have been split into the components isotopes to follow the respective decay chain; and not all materials of GEFF-2 produce nuclei which disintegrate within the assumed decay time of 10000 seconds

  7. National Emission Standards for Hazardous Air Pollutants Calendar Year 2001

    International Nuclear Information System (INIS)

    The Nevada Test Site (NTS) is operated by the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Operations Office (NNSA/NV) as the site for nuclear weapons testing, now limited to readiness activities, experiments in support of the national Stockpile Stewardship Program, and the activities listed below. Located in Nye County, Nevada, the site's southeast corner is about 88 km (55 mi) northwest of the major population center, Las Vegas, Nevada. The NTS covers about 3,561 km2 (1,375 mi2), an area larger than Rhode Island. Its size is 46 to 56 km (28 to 35 mi) east to west and from 64 to 88 km (40 to 55 mi) north to south. The NTS is surrounded, except on the south side, by public exclusion areas (Nellis Air Force Range [NAFR]) that provide another 24 to 104 km (15 to 65 mi) between the NTS and public lands (Figure 1.0). The NTS is characterized by desert valley and Great Basin mountain topography, with a climate, flora, and fauna typical of the southwest deserts. Population density within 150 km (93 mi) of the NTS is only about 0.2 persons per square kilometer, excluding the Las Vegas area. Restricted access, low population density in the surrounding area, and extended wind transport times are advantageous factors for the activities conducted at the NTS. Surface waters are scarce on the NTS, and slow-moving groundwater is present hundreds to thousands of feet below the land surface. The sources of radionuclides include current and previous activities conducted on the NTS (Figure 2.0). The NTS was the primary location for testing of nuclear explosives in the Continental U.S. between 1951 and 1992. Historical testing above or at ground surface has included (1) atmospheric testing in the 1950s and early 1960s, (2) earth-cratering experiments, and (3) open-air nuclear reactor and rocket engine testing. Since the mid-1950s, testing of nuclear explosive devices has occurred underground in drilled vertical holes or in mined tunnels (DOE 1996a

  8. Evaluation of skin entry kerma in radiological examinations at the Hospital de Clinicas, Parana, Brazil

    International Nuclear Information System (INIS)

    This paper evaluates the skin entry dose of pediatric and adults patients when submitted to radiological examinations at the Hospital de Clinicas do Parana, Brazil, as part integrate of the data assessment of International Atomic Energy Agency (IAEA) for Latin America. It was performed measurements of dose for evaluation of skin entry kerma in pediatric patients in thorax AP/PA examinations, adults of thorax in AP/PA, cranio caudal mammography and median lateral and patients of computerized tomography in examination of head, thorax and abdomen. The obtained data demonstrate the necessity of verification of diagnostic analysis standards. The great value amplitudes demonstrate the incompatibility of examination executions with those recommended by the literature. The dose values presented partially inside the range recommended and the other over the expected for the due examination when compared with the literature

  9. Project, construction and characterization of ionization chambers for use as standard systems in X and gamma radiation beams; Projeto, construcao e caracterizacao de camaras de ionizacao para utilizacao como sistemas padroes em feixes de radiacao X e gama

    Energy Technology Data Exchange (ETDEWEB)

    Perini, Ana Paula

    2013-07-01

    Ionization chambers present some advantages in relation to other dosimeters: easiness of handling, low energy dependence and high precision. The advantages associated to ionization chambers and the large number of diagnostic radiology exams and therapeutic treatments motivated the development of this PhD program. In this project ionization chambers were developed and characterized to be applied in diagnostic radiology and therapy beam dosimetry, with high precision and performance, in compliance with international recommendations. They were assembled in a simple way, utilizing low-cost national materials, so they can be reproduced and applied at calibration laboratories. The project of these ionization chambers presents some differences in relation to commercial ionization chambers, as the materials utilized and geometrical arrangements. Besides the development of the ionization chambers to be utilized in standard X-ray beam dosimetry as work standard systems, two graphite parallel-plate ionization chambers were developed and characterized to be applied as reference standard systems for determining the air kerma rates of gamma radiation sources. Comparing the air kerma rates determined with the reference standard of the Calibration Laboratory of IPEN, a Farmer ionization chamber, with the values of the air kerma rates obtained with the graphite ionization chambers, the maximum differences obtained were only 1.7% and 1.2% for the G1 and G2 graphite ionization chambers, respectively. Moreover, these ionization chambers presented correction factors close to 1.000, which is ideal for an ionization chamber be characterized as a reference standard system. (author)

  10. 76 FR 80261 - National Emission Standards for Hazardous Air Pollutants: Area Source Standards for Prepared...

    Science.gov (United States)

    2011-12-23

    ... Air Pollutant (HAP) emissions control (75 FR 533). We added the 95-percent design efficiency... published on January 5, 2010, (75 FR 522) if adverse comments are received on this direct final rule. If we.... V. What amendments are being made to this rule? On January 5, 2010 (75 FR 522), the EPA...

  11. 77 FR 30087 - Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards

    Science.gov (United States)

    2012-05-21

    ... Columbia EPA Environmental Protection Agency FR Federal Register NAAQS National Ambient Air Quality... ppm NAAQS set in 1997, but is set at a more protective level. \\2\\ See 73 FR 16436; March 27, 2008. For... 6, 2010. (See 75 FR 2938; January 19, 2010.) Because of the significant uncertainty the ozone...

  12. Analysis of the Tandem Calibration Method for Kerma Area Product Meters Via Monte Carlo Simulations

    International Nuclear Information System (INIS)

    The IAEA recommends that uncertainties of dosimetric measurements in diagnostic radiology for risk assessment and quality assurance should be less than 7% on the confidence level of 95%. This accuracy is difficult to achieve with kerma area product (KAP) meters currently used in clinics. The reasons range from the high energy dependence of KAP meters to the wide variety of configurations in which KAP meters are used and calibrated. The tandem calibration method introduced by Poeyry, Komppa and Kosunen in 2005 has the potential to make the calibration procedure simpler and more accurate compared to the traditional beam-area method. In this method, two positions of the reference KAP meter are of interest: (a) a position close to the field KAP meter and (b) a position 20 cm above the couch. In the close position, the distance between the two KAP meters should be at least 30 cm to reduce the effect of back scatter. For the other position, which is recommended for the beam-area calibration method, the distance of 70 cm between the KAP meters was used in this study. The aim of this work was to complement existing experimental data comparing the two configurations with Monte Carlo (MC) simulations. In a geometry consisting of a simplified model of the VacuTec 70157 type KAP meter, the MCNP code was used to simulate the kerma area product, PKA, for the two (close and distant) reference planes. It was found that PKA values for the tube voltage of 40 kV were about 2.5% lower for the distant plane than for the close one. For higher tube voltages, the difference was smaller. The difference was mainly caused by attenuation of the X ray beam in air. Since the problem with high uncertainties in PKA measurements is also caused by the current design of X ray machines, possible solutions are discussed. (author)

  13. Development of a calibration methodology and tests of kerma area product meters

    International Nuclear Information System (INIS)

    The quantity kerma area product (PKA) is important to establish reference levels in diagnostic radiology exams. This quantity can be obtained using a PKA meter. The use of such meters is essential to evaluate the radiation dose in radiological procedures and is a good indicator to make sure that the dose limit to the patient's skin doesn't exceed. Sometimes, these meters come fixed to X radiation equipment, which makes its calibration difficult. In this work, it was developed a methodology for calibration of PKA meters. The instrument used for this purpose was the Patient Dose Calibrator (PDC). It was developed to be used as a reference to check the calibration of PKA and air kerma meters that are used for dosimetry in patients and to verify the consistency and behavior of systems of automatic exposure control. Because it is a new equipment, which, in Brazil, is not yet used as reference equipment for calibration, it was also performed the quality control of this equipment with characterization tests, the calibration and an evaluation of the energy dependence. After the tests, it was proved that the PDC can be used as a reference instrument and that the calibration must be performed in situ, so that the characteristics of each X-ray equipment, where the PKA meters are used, are considered. The calibration was then performed with portable PKA meters and in an interventional radiology equipment that has a PKA meter fixed. The results were good and it was proved the need for calibration of these meters and the importance of in situ calibration with a reference meter. (author)

  14. Dosimetry and kVp standardization for quality assurance of mammography

    International Nuclear Information System (INIS)

    Breast cancer mortality rates were significantly reduced in Taiwan after achieving early-stage monitoring with mammography screening. This study establishes an appropriate and traceable calibration infrastructure, which offers calibration services for mammography X-ray quality assurance instrumentation, which is performed clinically on a regular basis. The entrance air kerma, HVL, and kVp of mammography equipment with five different target/filter combinations can be taken as adequate indicators for the level of average glandular dose (AGD). The primary dose standard in mammography uses a free-air ionization chamber to estimate the rate of air kerma. Several correction factors were determined by Monte Carlo simulations and experiments. A secondary kVp standard in mammography is in accordance with the IEC 61676 recommendations. The calibration system of kVp meter uses a high-voltage divider, which is traceable to ITRI primary standard in Taiwan. Dose and kVp verifications were conducted by mammography instruments, which were previously calibrated by NIST and PTB. The evaluation results indicate that the capabilities of this irradiation system met the ISO 4037-1 requirements. The expanded uncertainties (k=2) were 1.03% and 1.6% when the mammography X-ray air kerma rate and kVp meter calibration factors were evaluated using ISO GUM. Experimental verification and a comparison with NIST using transfer ionization chambers yielded differences in calibration factors. Comparison with the PTB using kVp meter indicated a less than 1% difference. The results showed that dose and kVp standards were in reasonable agreement with standard uncertainty. The low uncertainties associated with the obtained results in this work show that the standardization employed can be accurately used for calibration of instrument in mammography in Taiwan. - Highlights: • We established calibration infrastructure for mammography X-ray quality assurance. • The expanded uncertainty of calibration

  15. 75 FR 67361 - Release of Final Document Related to the Review of the National Ambient Air Quality Standards for...

    Science.gov (United States)

    2010-11-02

    ... final document titled Policy Assessment for the Review of the Carbon Monoxide National Ambient Air... the Plan for Review of the National Ambient Air Quality Standards for Carbon Monoxide (EPA 452R-08-005... AGENCY Release of Final Document Related to the Review of the National Ambient Air Quality Standards...

  16. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Science.gov (United States)

    2010-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... SECONDARY AMBIENT AIR QUALITY STANDARDS Pt. 50, App. S Appendix S to Part 50—Interpretation of the Primary... be submitted to EPA's Air Quality System (AQS), or otherwise available to EPA, meeting...

  17. Application of air-lifting pump in standard spray-sieve-plates pulsed extraction column

    International Nuclear Information System (INIS)

    The present research aims to determine the application of air-lifting pump in 100 mm diameter standard spray-sieve-plates pulsed extraction column for 30%TRPO/ kerosene solution-1 mol/L HNO3 solution. The liquid flow rate of air-lifting pump, designed for aqueous phase feeding, organic phase feeding and aqueous phase discharging, increases linearly with air flow rate within experimental range, and the submerged ratio of the air-lifting pump for aqueous phase discharging is linear with the holdup of the pulsed extraction column. By combining above results with the online measurement of air-purge method, the steady state of pulsed extraction column is easily controlled. (authors)

  18. National Emission Standards for Hazardous Air Pollutants—Calendar Year 2010 INL Report for Radionuclides (2011)

    Energy Technology Data Exchange (ETDEWEB)

    Mark Verdoorn; Tom Haney

    2011-06-01

    This report documents the calendar Year 2010 radionuclide air emissions and resulting effective dose equivalent to the maximally exposed individual member of the public from operations at the Department of Energy's Idaho National Laboratory Site. This report was prepared in accordance with the Code of Federal Regulations, Title 40, 'Protection of the Environment,' Part 61, 'National Emission Standards for Hazardous Air Pollutants,' Subpart H, 'National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities.'

  19. IMT-2000 Satellite Standards with Applications to Mobile Air Traffic Communications Networks

    Science.gov (United States)

    Shamma, Mohammed A.

    2004-01-01

    The International Mobile Telecommunications - 2000 (IMT-2000) standard and more specifically the Satellite component of it, is investigated as a potential alternative for communications to aircraft mobile users en-route and in terminal area. Its application to Air Traffic Management (ATM) communication needs is considered. A summary of the specifications of IMT-2000 satellite standards are outlined. It is shown via a system research analysis that it is possible to support most air traffic communication needs via an IMT-2000 infrastructure. This technology can compliment existing, or future digital aeronautical communications technologies such as VDL2, VDL3, Mode S, and UAT.

  20. US power plant carbon standards and clean air and health co-benefits

    Science.gov (United States)

    Driscoll, Charles T.; Buonocore, Jonathan J.; Levy, Jonathan I.; Lambert, Kathleen F.; Burtraw, Dallas; Reid, Stephen B.; Fakhraei, Habibollah; Schwartz, Joel

    2015-06-01

    Carbon dioxide emissions standards for US power plants will influence the fuels and technologies used to generate electricity, alter emissions of pollutants such as sulphur dioxide and nitrogen oxide, and influence ambient air quality and public health. We present an analysis of how three alternative scenarios for US power plant carbon standards could change fine particulate matter and ozone concentrations in ambient air, and the resulting public health co-benefits. The results underscore that carbon standards to curb global climate change can also provide immediate local and regional health co-benefits, but the magnitude depends on the design of the standards. A stringent but flexible policy that counts demand-side energy efficiency towards compliance yields the greatest health benefits of the three scenarios analysed.

  1. Savannah River Site radionuclide air emissions annual report for national emission standards for hazardous air pollutants

    International Nuclear Information System (INIS)

    The radiological air emission sources at the SRS have been divided into three categories, Point, Grouped and Non-Point, for this report. Point sources, analyzed individually, are listed with a listing of the control devices, and the control device efficiency. The sources listed have been grouped together either for security reasons or where individual samples are composited for analytical purposes. For grouped sources the listed control devices may not be on all sources within a group. Point sources that did not have continuous effluent monitoring/sampling in 1993 are noted. The emissions from these sources was determined from Health Protection smear data, facility radionuclide content or other calculational methods, including process knowledge, utilizing existing analytical data. This report also contain sections on facility descriptions, dose assessment, and supplemental information

  2. 75 FR 32682 - National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...

    Science.gov (United States)

    2010-06-09

    ... the deadline for written comments on the proposed rules (75 FR 32006 (major source boilers), 75 FR 31896 (area source boilers), 75 FR 31938 (CISWI), and 75 FR 31844 (waste definition)) to August 3, 2010... 2050-AG44 National Emission Standards for Hazardous Air Pollutants for Major Sources:...

  3. 76 FR 72507 - National Emissions Standards for Hazardous Air Pollutants: Ferroalloys Production

    Science.gov (United States)

    2011-11-23

    ... Reporting Tool FR Federal Register gr/dscf grains per dry standard cubic foot HAP hazardous air pollutants...-Product Recovery Plants (Benzene NESHAP) (54 Federal Register (FR) 38044, September 14, 1989). The first... is no higher than approximately one in 10 thousand, that risk level is considered acceptable.'' 54...

  4. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2011-07-27

    ... 6x4 tractor with a 190-inch wheelbase, equipped with a hybrid disc brake configuration. The vehicle... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AK84 Federal Motor Vehicle Safety... published a final rule that amended the Federal motor vehicle safety standard for air brake systems...

  5. 78 FR 7487 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial...

    Science.gov (United States)

    2013-02-01

    .... The EPA implemented this provision in 1999 in the Integrated Urban Air Toxics Strategy, (64 FR 38715... reads: ``A boiler required to have a permit under section 3005 of the Solid Waste Disposal Act or... standards based on GACT for the urban HAP, other than Hg and POM, emitted from coal-fired boilers that...

  6. Ambient air quality standards and guidelines in some countries. Ilmanlaadun ohjearvot ja normit muissa maissa

    Energy Technology Data Exchange (ETDEWEB)

    Mroueh, U.M.; Laukkarinen, A.

    1987-01-01

    The World Health Organization (WHO) initiated in 1973 the WHO Environmental Health Criteria Programme, the result of which is a series of criteria documents concerning most significant air pollutants (sulfur dioxide, suspended particulate matter, nitrogen dioxide, carbon monoxide, photochemical oxidants and ozone). The objective of the programme was to provide national authorities guidelines for setting exposure limits consistent with the protection of public health. Most national standards are based on the WHO guidelines when health effects are concerned. One important aspect when evaluating standards and guidelines applied in different countries, is the capability of the authorities to monitor and manage the quality of ambient air. In some standards whole the assessment system (monitoring stations, sampling frequency, instrumentation, data evaluation etc.) is precisely specified whereas others define only the measuring methods. For the present only European Communities have attempted to harmonize both air quality regulations and the assessment system throughout the territory of member states. The most significant member states have issued also air quality standards of their own differing from EC values, and according to some international experts the effects of EC limit values are minor so far.

  7. 77 FR 16508 - National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins...

    Science.gov (United States)

    2012-03-21

    ..., was published on January 9, 2012 (77 FR 1268). EPA has established the public docket for the proposed...: Group IV Polymers and Resins; Pesticide Active Ingredient Production; and Polyether Polyols Production... pollutants: National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and...

  8. 78 FR 10005 - National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing...

    Science.gov (United States)

    2013-02-12

    ... Reporting Tool FR Federal Register gr/dscf grains per dry standard cubic foot HAP hazardous air pollutants... Information Document. On July 18, 2012 (77 FR 42368), the EPA proposed to amend the Portland cement... A. PM Parametric Monitoring B. Scaling for Continuous Parametric Monitoring of THC for...

  9. 40 CFR 60.752 - Standards for air emissions from municipal solid waste landfills.

    Science.gov (United States)

    2010-07-01

    ... municipal solid waste landfills. 60.752 Section 60.752 Protection of Environment ENVIRONMENTAL PROTECTION... of Performance for Municipal Solid Waste Landfills § 60.752 Standards for air emissions from municipal solid waste landfills. (a) Each owner or operator of an MSW landfill having a design capacity...

  10. 76 FR 81903 - National Emission Standards for Hazardous Air Pollutants: Ferroalloys Production; Extension of...

    Science.gov (United States)

    2011-12-29

    ... Pollutants: Ferroalloys Production'' is being extended for 22 days. DATES: Comments. The public comment period for the proposed rule published November 23, 2011 (76 FR 72508), is being extended for 22 days to... AGENCY 40 CFR Part 63 RIN 2060-AQ11 National Emission Standards for Hazardous Air Pollutants:...

  11. 77 FR 555 - National Emissions Standards for Hazardous Air Pollutants From Secondary Lead Smelting

    Science.gov (United States)

    2012-01-05

    ... UPL upper prediction limit WWW World Wide Web Background Information Document. On May 19, 2011 (76 FR... (62 FR 32216). The standards are codified at 40 CFR part 63, subpart X. The secondary lead smelting... Hazardous Air Pollutants From Secondary Lead Smelting; Final Rules #0;#0;Federal Register / Vol. 77 , No....

  12. [A comparative study on domestic and foreign emission standards of air pollutants for cement industry].

    Science.gov (United States)

    Jiang, Mei; Li, Xiao-Qian; Ji, Liang; Zou, Lan; Wei, Yu-Xia; Zhao, Guo-Hua; Che, Fei; Li, Gang; Zhang, Guo-Ning

    2014-12-01

    The new National Emission Standard of Air Pollutants for Cement Industry (GB 4915-2013) becomes effective on Mar. 1st, 2014. It will play an important role in pollution prevention, total emission reduction, structure adjustment, and layout optimization for cement industry. Based on the research of emission standard in China, U. S., EU and Japan, the similarities and differences in the pollutant projects, control indicators, limits and means of implementation were discussed and advice was proposed, with the purpose to provide a reference for revision of emission standard, and to improve the level of environmental management and pollution control. PMID:25826950

  13. The 1998 calibration of Australian secondary standards of exposure and absorbed dose at 60Co

    International Nuclear Information System (INIS)

    New calibration factors are reported for several of the ionization chambers maintained at the Australian Radiation Laboratory (ARL) and at the Australian Nuclear Science and Technology Organisation (ANSTO) as Australian secondary standards of exposure/air kerma and absorbed dose at 60Co. These calibration factors supplement or replace the calibration factors given in earlier reports. Updated 90Sr reference source data are given for the ARL chambers, and for two of the ANSTO chambers. These results confirm the stability of the secondary standards. A re-calibration of the ANSTO reference electrometer is reported. This was carried out using an improved method, which is fully described

  14. National Emission Standards for Hazardous Air Pollutants—Calendar Year 2011 INL Report for Radionuclides (2012)

    Energy Technology Data Exchange (ETDEWEB)

    Mark Verdoorn; Tom Haney

    2012-06-01

    This report documents the calendar year 2011 radionuclide air emissions and resulting effective dose equivalent to the maximally exposed individual member of the public from operations at the Department of Energy's Idaho National Laboratory Site. This report was prepared in accordance with the Code of Federal Regulations, Title 40, 'Protection of the Environment,' Part 61, 'National Emission Standards for Hazardous Air Pollutants,' Subpart H, 'National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities.' The effective dose equivalent to the maximally exposed individual member of the public was 4.58E-02 mrem per year, 0.46 percent of the 10 mrem standard.

  15. National Emission Standards for Hazardous Air Pollutants. Calendar Year 2013 INL Report for Radionuclides [2014

    Energy Technology Data Exchange (ETDEWEB)

    Verdoorn, Mark; Haney, Tom

    2014-06-01

    This report documents the calendar year 2013 radionuclide air emissions and resulting effective dose equivalent to the maximally exposed individual member of the public from operations at the Department of Energy’s Idaho National Laboratory Site. This report was prepared in accordance with the Code of Federal Regulations, Title 40, ''Protection of the Environment,'' Part 61, ''National Emission Standards for Hazardous Air Pollutants,'' Subpart H, ''National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities.'' The effective dose equivalent to the maximally exposed individual member of the public was 3.02 E-02 mrem per year, 0.30 percent of the 10 mrem standard.

  16. National Emission Standards for Hazardous Air Pollutants. Calendar Year 2012 INL Report for Radionuclides (2013)

    Energy Technology Data Exchange (ETDEWEB)

    Verdoorn, Mark; Haney, Tom

    2013-06-01

    This report documents the calendar year 2011 radionuclide air emissions and resulting effective dose equivalent to the maximally exposed individual member of the public from operations at the Department of Energy’s Idaho National Laboratory Site. This report was prepared in accordance with the Code of Federal Regulations, Title 40, ''Protection of the Environment,'' Part 61, ''National Emission Standards for Hazardous Air Pollutants,'' Subpart H, ''National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities.'' The effective dose equivalent to the maximally exposed individual member of the public was 4.58E-02 mrem per year, 0.46 percent of the 10 mrem standard.

  17. Secondary bremsstrahlung and the energy-conservation aspects of kerma in photon-irradiated media

    Science.gov (United States)

    Kumar, Sudhir; Nahum, Alan E.

    2016-02-01

    Kerma, collision kerma and absorbed dose in media irradiated by megavoltage photons are analysed with respect to energy conservation. The user-code DOSRZnrc was employed to compute absorbed dose D, kerma K and a special form of kerma, K ncpt, obtained by setting the charged-particle transport energy cut-off very high, thereby preventing the generation of ‘secondary bremsstrahlung’ along the charged-particle paths. The user-code FLURZnrc was employed to compute photon fluence, differential in energy, from which collision kerma, K col and K were derived. The ratios K/D, K ncpt/D and K col/D have thereby been determined over a very large volumes of water, aluminium and copper irradiated by broad, parallel beams of 0.1 to 25 MeV monoenergetic photons, and 6, 10 and 15 MV ‘clinical’ radiotherapy qualities. Concerning depth-dependence, the ‘area under the kerma, K, curve’ exceeded that under the dose curve, demonstrating that kerma does not conserve energy when computed over a large volume. This is due to the ‘double counting’ of the energy of the secondary bremsstrahlung photons, this energy being (implicitly) included in the kerma ‘liberated’ in the irradiated medium, at the same time as this secondary bremsstrahlung is included in the photon fluence which gives rise to kerma elsewhere in the medium. For 25 MeV photons this ‘violation’ amounts to 8.6%, 14.2% and 25.5% in large volumes of water, aluminium and copper respectively but only 0.6% for a ‘clinical’ 6 MV beam in water. By contrast, K col/D and K ncpt/D, also computed over very large phantoms of the same three media, for the same beam qualities, are equal to unity within (very low) statistical uncertainties, demonstrating that collision kerma and the special type of kerma, K ncpt, do conserve energy over a large volume. A comparison of photon fluence spectra for the 25 MeV beam at a depth of  ≈51 g cm-2 for both very high and very low charged-particle transport cut

  18. Air Quality Standards for Particulate Matter (PM) at high altitude cities

    International Nuclear Information System (INIS)

    The Air Quality Standards for Particulate Matter (PM) at high altitude urban areas in different countries, must consider the pressure and temperature due to the effect that these parameters have on the breath volume. This paper shows the importance to correct Air Quality Standards for PM considering pressure and temperature at different altitudes. Specific factors were suggested to convert the information concerning PM, from local to standard conditions, and adjust the Air Quality Standards for different high altitudes cities. The correction factors ranged from: 1.03 for Santiago de Chile to 1.47 for El Alto Bolivia. Other cities in this study include: Mexico City, México; La Paz, Bolivia; Bogota, Cali and Medellin, Colombia; Quito, Ecuador and Cuzco, Peru. If these corrections are not considered, the atmospheric concentrations will be underestimated. - Highlights: ► AQS for particulate matter concentrations adjusted by pressure and temperature. ► Particulate matter concentrations can be underestimated in high altitude Cities. ► Particulate matter concentrations must be compared under the same conditions. - In order to compare high altitude atmospheric PM concentrations with AQS, one must consider T and P of the sampling site.

  19. Design and preliminary test of a free-air ionization chamber for low-energy X-ray

    Institute of Scientific and Technical Information of China (English)

    WU Jin-Jie; YANG Yuan-Di; WANG Pei-Wei; CHEN Jing; LIU Jia-Cheng

    2011-01-01

    A free-air ionization chamber in low-energy X-ray has been designed and manufactured at theNational Institute of Metrology (NIM, China) according to the defination of alr-kerma. The results of a preliminary test show that the leakage current of ionization chamber is around 2×10A, and the correction factor of ion recombination for the ionization chamber is also obtained. The free-air ionization chamber is suitable for the primary standard in low-energy X-rays.

  20. Calculated in-air leakage spectra and power levels for the ANSI standard minimum accident of concern. Final report

    International Nuclear Information System (INIS)

    This document represents Phase I of a two-phase project. The entire project consists of determining a series of minimum accidents of concern and their associated neutron and photon leakage spectra that may be used to determine Criticality Accident Alarm compliance with ANSI/ANS-8.3. The inadvertent assembly of a critical mass of material presents a multitude of unknown quantities. Depending on the particular process, one can make an educated guess as to fissile material. In a gaseous diffusion cascade, this material is assumed to be uranyl fluoride. However, educated assumptions cannot be readily made for the other variables. Phase I of this project is determining a bounding minimum accident of concern and its associated neutron and photon leakage spectra. To determine the composition of the bounding minimum accident of concern, work was done to determine the effects of geometry, moderation level, and enrichment on the leakage spectra of a critical assembly. The minimum accident of concern is defined as the accident that may be assumed to deliver the equivalent of an absorbed dose in free air of 20 rad at a distance of 2 meters from the reacting material within 60 seconds. To determine this dose, an analyst makes an assumption and choose an appropriate flux to dose response function. The power level required of a critical assembly to constitute a minimum accident of concern depends heavily on the response function chosen. The first step in determining the leakage spectra was to attempt to isolate the effects of geometry, after which all calculations were conducted on critical spheres. The moderation level and enrichment of the spheres were varied and their leakage spectra calculated. These spectra were then multiplied by three different response functions: the Henderson Flux to Dose conversion factors, the ICRU 44 Kerma in Air, and the MCNP Heating Detector. The power level required to produce a minimum accident of concern was then calculated for each combination

  1. 76 FR 20347 - Release of Draft Integrated Review Plan for the National Ambient Air Quality Standards for Lead

    Science.gov (United States)

    2011-04-12

    ... (75 FR 8934). The draft IRP is being made available for consultation with CASAC and for public comment... AGENCY Release of Draft Integrated Review Plan for the National Ambient Air Quality Standards for Lead... National Ambient Air Quality Standards for Lead (draft IRP). This document contains the plans for...

  2. 75 FR 32178 - Release of Final Document Related to the Review of the National Ambient Air Quality Standards for...

    Science.gov (United States)

    2010-06-07

    ... titled, Carbon Monoxide National Ambient Air Quality Standards: Scope and Methods Plan for Health Risk... AGENCY Release of Final Document Related to the Review of the National Ambient Air Quality Standards for... describes ] quantitative analyses that have been conducted as part of the review of the National Ambient...

  3. 75 FR 11877 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-03-12

    ... AGENCY Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides... Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur: First External Review Draft... (welfare-based) NAAQS for oxides of nitrogen (NO X ) and oxides of sulfur (SO X ). Because NO X , SO...

  4. 75 FR 57463 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-09-21

    ... AGENCY Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides... Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur: Second External Review Draft... for oxides of nitrogen (NO X ) and oxides of sulfur (SO X ). Because NO X , SO X , and...

  5. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National 8-hour primary and secondary....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  6. Implementation of the Brazilian primary standard for x-rays

    International Nuclear Information System (INIS)

    In the field of ionizing radiation metrology, a primary standard of a given physical quantity is essentially an experimental set-up which allows one to attribute a numerical value to a particular sample of that quantity in terms of a unit given by an abstract definition. The absolute measurement of the radiation quantity air kerma, is performed with a free-air ionization chamber. A great deal of research to determine the absolute measurement resulted in different designs for primary standard free-air ionization chambers such as cilindrics or plane parallel chambers. The implementation of primary standard dosimetry with free-air ionization chambers is limited to the National Metrology Institutes - NMIs. Since 1975, the Bureau International des Poids et Mesures - BIPM has been conducting comparisons of NMIs primary free-air standard chambers in the medium energy x-rays range. These comparisons are carried out indirectly through the calibration at both the BIPM and at the NMI of one or more transfer ionization chambers at a series of four reference radiation qualities. The scientific work programme of the National Laboratory for Ionizing Radiation Metrology - LNMRI of the Institute of Radioprotection and Dosimetry - IRD, which belongs to the National Commission of Nuclear Energy - CNEN, includes the establishment of a primary standard for x-rays of medium energy x-ray range. This activity is justified by the demand to calibrate periodically Brazilian network of the secondary standards without losing quality of the measurement. The LNMRI decided to implement four reference radiation qualities establishing the use of a transfer chamber calibrated at BIPM. The LNMRI decided to implement the primary standard dosimetry using a free-air ionization chamber with variable volume, made by Victoreen, model 480. Parameters related to the measurement of the quantity air kerma were evaluated, such as: air absorption, scattering inside the ionization chamber, saturation, beam

  7. Experimental determination of kerma factors at E/sub n/ approx. = 15 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, E.; Slaughter, D.R.; Howell, R.H.

    1978-04-05

    Experimental values for the kerma per unit fluence at the neutron energy, E/sub n/ = 15 MeV, have been determined for graphite, Mg, and Fe. Ion chambers of small size with walls of these materials were employed, and were filled with a variety of gases--N/sub 2/, CO/sub 2/, Ne, Ar, Kr, and Xe. A calibrated neutron source was employed, allowing a straightforward determination of the kerma per unit fluence.

  8. Impact of NOx vehicle emission standards failure on Air Quality in Europe

    OpenAIRE

    Borken-Kleefeld, J.; Kiesewetter, G.; Papageorgiou, T.; Ntziachristos, L.

    2012-01-01

    Vehicle exhaust emission standards have been tightened in the EU for several decades now, in order to protect health and the environment. This has led to a substantial decrease in total pollutant emissions, despite the growing volumes of passenger and freight transport. However, national emissions, particularly of NOx, exceed the ceilings accorded under the Gothenburg Protocol of the UNECE's Convention on Long-Range Transboundary Air Pollution (LRTAP) (EEA 2012) in twelve EU Member States. T...

  9. Air

    International Nuclear Information System (INIS)

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  10. Potential energy savings and environmental impacts of energy efficiency standards for vapor compression central air conditioning units in China

    Energy Technology Data Exchange (ETDEWEB)

    Lu Wei [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China)]. E-mail: tjluwei@163.com

    2007-03-15

    Owing to the rapid development of economy and the stable improvement of people's living standard, central air conditioning units are broadly used in China. This not only consumes large energy, but also results in adverse energy-related environmental issues. Energy efficiency standards are accepted effective policy tools to reduce energy consumption and pollutant emissions. Recently, China issued two national energy efficiency standards, GB19577-2004 and GB19576-2004, for vapor compression central air conditioning units for the first time. This paper first reviews the two standards, and then establishes a mathematic model to evaluate the potential energy savings and environmental impacts of the standards. The estimated results indicate implementing these standards will save massive energy, as well as benefit greatly to the environment. Obviously, it is significant to implement energy efficiency standards for central air conditioning units in China.

  11. Evaluation of skin entry kerma in radiological examinations at the Hospital de Clinicas, Parana, Brazil; Avaliacao de kerma de entrada na pele em exames radiologicos no Hospital de Clinicas do Parana, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Lorena E.; Schelin, Hugo R.; Santos, Amanda C. dos; Bunick, Ana Paula; Paschuk, Sergei; Denyak, Valeriy [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Tilly Junior, Joao G. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Hospital de Clinicas; Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE/DEN), Recife, PE (Brazil). Dept. de Energia Nuclear

    2011-10-26

    This paper evaluates the skin entry dose of pediatric and adults patients when submitted to radiological examinations at the Hospital de Clinicas do Parana, Brazil, as part integrate of the data assessment of International Atomic Energy Agency (IAEA) for Latin America. It was performed measurements of dose for evaluation of skin entry kerma in pediatric patients in thorax AP/PA examinations, adults of thorax in AP/PA, cranio caudal mammography and median lateral and patients of computerized tomography in examination of head, thorax and abdomen. The obtained data demonstrate the necessity of verification of diagnostic analysis standards. The great value amplitudes demonstrate the incompatibility of examination executions with those recommended by the literature. The dose values presented partially inside the range recommended and the other over the expected for the due examination when compared with the literature

  12. National standards of effective dose calculation for diagnostic and interventional radiology procedures

    International Nuclear Information System (INIS)

    Currently, national standards for diagnostic and therapeutic procedures using ionizing radiation are developed in the Czech Republic. The standards are divided into four main categories, three of them are clinical standards for procedures in diagnostic/interventional radiology, radiation therapy and nuclear medicine. The last one is a medical physics standard for dose assessment in diagnostic/interventional radiology and nuclear medicine. The diagnostic and interventional radiology part of the medical physics standard is discussed here. The medical physics standard for diagnostic and interventional radiology involves a computation of risk related quantities, it means an effective dose and a mean glandular dose (MGD). The standard is divided into seven separate articles concerning general radiography, mammography, panoramic radiography, intraoral radiography, computed tomography, fluoroscopy and interventional radiology. Each part contains a list of exposure parameters of a given patient and a list of given X ray machine parameters, which are required for an examination reconstruction and dose calculation. Detailed instructions on how to compute the effective dose or MGD from the given data follows. For the calculation, PCXMC program is recommended for radiography and fluoroscopy examinations and ImPACT spreadsheet with NRPB SR250 data is used for computed tomography. For mammography, a dose formalism suggested by Dance is used for the calculation of MGD. Directly measurable quantities used as an input for the calculations are incident air kerma Ki for mammography, weighted computed tomography kerma index CTKIw for computed tomography, entrance surface air kerma Ke or product of kerma and area PKL for general radiography, fluoroscopy and interventional radiology. These directly measurable dose quantities are based on kerma instead of absorbed dose, as recommended by IAEA and ICRU. The medical physics standard should help to implement this new 'kerma formalism' into

  13. DS02 fluence spectra for neutrons and gamma rays at Hiroshima and Nagasaki with fluence-to-kerma coefficients and transmission factors for sample measurements.

    Science.gov (United States)

    Egbert, Stephen D; Kerr, George D; Cullings, Harry M

    2007-11-01

    Fluence spectra at several ground distances in Hiroshima and Nagasaki are provided along with associated fluence-to-kerma coefficients from the Dosimetry System 2002 (DS02). Also included are transmission factors for calculating expected responses of in situ sample measurements of neutron activation products such as (32)P,(36)Cl,(39)Ar,(41)Ca, (60)Co,(63)Ni,(152)Eu, and (154)Eu. The free-in-air (FIA) fluences calculated in 2002 are available for 240 angles, 69 energy groups, 101 ground distances, 5 heights, 4 radiation source components, 2 cities. The DS02 code uses these fluences partitioned to a prompt and delayed portion, collapsed to 58 energy groups and restricted to 97 ground distances. This is because the fluence spectra were required to be in the same format that was used in the older Dosimetry System 1986 (DS86) computer code, of which the DS02 computer code is a modification. The 2002 calculation fluences and the collapsed DS02 code fluences are presented and briefly discussed. A report on DS02, which is available on the website at the Radiation Effects Research Foundation, provides tables and figures of the A-bomb neutron and gamma-ray output used as the sources in the 2002 radiation transport calculations. While figures illustrating the fluence spectra at several ground ranges are presented in the DS02 Report, it does not include any tables of the calculated fluence spectra in the DS02 report. This paper provides, at several standard distances from the hypocenter, the numerical information which is required to translate the FIA neutron fluences given in DS02 to a neutron activation measurement or neutron and gamma-ray soft-tissue dose. PMID:17643260

  14. Hospital ventilation standards and energy conservation: chemical contamination of hospital air. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rainer, D.; Michaelsen, G.S.

    1980-03-01

    In an era of increasing energy conservation consciousness, a critical reassessment of the validity of hospital ventilation and thermal standards is made. If current standards are found to be excessively conservative, major energy conservation measures could be undertaken by rebalancing and/or modification of current HVAC systems. To establish whether or not reducing ventilation rates would increase airborne chemical contamination to unacceptable levels, a field survey was conducted to develop an inventory and dosage estimates of hospital generated airborne chemical contaminants to which patients, staff, and visitors are exposed. The results of the study are presented. Emphasis is on patient exposure, but an examination of occupational exposure was also made. An in-depth assessment of the laboratory air environment is documented. Housekeeping products used in survey hospitals, hazardous properties of housekeeping chemicals and probable product composition are discussed in the appendices.

  15. 75 FR 61486 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-10-05

    ... an atmospheric chemistry perspective as well as from an environmental effects perspective, and... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and...

  16. Role of science and judgment in setting national ambient air quality standards: how low is low enough?

    OpenAIRE

    McClellan, Roger O.

    2011-01-01

    The Clean Air Act (CAA) requires listing as criteria air pollutants those pollutants that arise from multiple sources and are found across the United States. The original list included carbon monoxide, nitrogen oxides, sulfur oxides, particulate matter, photochemical oxidants (later regulated as ozone), and hydrocarbons. Later, the listing of hydrocarbons was revoked and lead was listed. The CAA requires the EPA Administrator to set National Ambient Air Quality Standards (NAAQS) for these pol...

  17. Development, enhancement, and evaluation of aircraft measurement techniques for national ambient air quality standard criteria pollutants

    Science.gov (United States)

    Brent, Lacey Cluff

    The atmospheric contaminants most harmful to human health are designated Criteria Pollutants. To help Maryland attain the national ambient air quality standards (NAAQS) for Criteria Pollutants, and to improve our fundamental understanding of atmospheric chemistry, I conducted aircraft measurements in the Regional Atmospheric Measurement Modeling Prediction Program (RAMMPP). These data are used to evaluate model simulations and satellite observations. I developed techniques for improving airborne observation of two NAAQS pollutants, particulate matter (PM) and nitrogen dioxide (NO2). While structure and composition of organic aerosol are important for understanding PM formation, the molecular speciation of organic ambient aerosol remains largely unknown. The spatial distribution of reactive nitrogen is likewise poorly constrained. To examine water-soluble organic aerosol (WSOA) during an air pollution episode, I designed and implemented a shrouded aerosol inlet system to collect PM onto quartz fiber filters from a Cessna 402 research aircraft. Inlet evaluation conducted during a side-by-side flight with the NASA P3 demonstrated agreement to within 30%. An ion chromatographic mass spectrometric method developed using the NIST Standard Reference Material (SRM) 1649b Urban Dust, as a surrogate material resulted in acidic class separation and resolution of at least 34 organic acids; detection limits approach pg/g concentrations. Analysis of aircraft filter samples resulted in detection of 8 inorganic species and 16 organic acids of which 12 were quantified. Aged, re-circulated metropolitan air showed a greater number of dicarboxylic acids compared to air recently transported from the west. While the NAAQS for NO2 is rarely exceeded, it is a precursor molecule for ozone, America's most recalcitrant pollutant. Using cavity ringdown spectroscopy employing a light emitting diode (LED), I measured vertical profiles of NO2 (surface to 2.5 km) west (upwind) of the Baltimore

  18. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Science.gov (United States)

    2010-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  19. Study on an Air Quality Evaluation Model for Beijing City Under Haze-Fog Pollution Based on New Ambient Air Quality Standards

    OpenAIRE

    Li Li(State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China); Dong-Jun Liu

    2014-01-01

    Since 2012, China has been facing haze-fog weather conditions, and haze-fog pollution and PM2.5 have become hot topics. It is very necessary to evaluate and analyze the ecological status of the air environment of China, which is of great significance for environmental protection measures. In this study the current situation of haze-fog pollution in China was analyzed first, and the new Ambient Air Quality Standards were introduced. For the issue of air quality evaluation, a comprehensive eval...

  20. 78 FR 29815 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

    Science.gov (United States)

    2013-05-21

    ...This action would establish more stringent vehicle emissions standards and reduce the sulfur content of gasoline beginning in 2017, as part of a systems approach to addressing the impacts of motor vehicles and fuels on air quality and public health. The proposed gasoline sulfur standard would make emission control systems more effective for both existing and new vehicles, and would enable more......

  1. 76 FR 45011 - Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test...

    Science.gov (United States)

    2011-07-27

    ... Procedures for Aircraft;'' Final Rule, 38 FR 19088, July 17, 1973. \\12\\ U.S. EPA, ``Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures;'' Final Rule, 62 FR 25356... Engines; Emission Standards and Test Procedures;'' Final Rule, 70 FR 2521, November 17, 2005. E....

  2. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Science.gov (United States)

    2010-07-01

    ...-hour standards are codified in 40 CFR part 81. (c) EPA's authority under paragraph (b) of this section... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National 1-hour primary and secondary....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level...

  3. Characterization of a 137Cs standard source for calibration purposes ar CRCN-NE

    International Nuclear Information System (INIS)

    Radiation protection monitoring instruments should be calibrated by accredited calibration laboratories. To offer calibration services, a laboratory must accomplish all requirements established by the national regulatory agency. The Calibration Service of the Centro Regional de Ciencias Nucleares (CRCN-NE), Comissao Nacional de Energia Nuclear, Recife, Brazil, is trying to achieve this accreditation. In the present work, a 137Cs standard source was characterized following the national and international recommendations and the results are presented. This source is a commercially available single source irradiator model 28-8A, manufactured by JLShepherd and Associates, with initial activity of 444 GBq (05/13/03). To provide different air kerma rates, as required for the calibration of portable radiation monitors, this irradiator have a set of four lead attenuators with different thickness, providing attenuation factors equal to 2, 4, 10 and 100 times (nominally). The performed tests included: size and uniformity of the radiation standard field at calibration reference position, variation of the air kerma rate for different lead attenuators, determination of attenuation factors for each lead attenuator configuration, and determination of the radiation scattering at the calibration reference position. The results showed the usefulness of the 137Cs standard source for the calibration of radiation protection monitoring detectors. (author)

  4. Nonattainment of national ambient air quality standards: implications for energy policy

    Energy Technology Data Exchange (ETDEWEB)

    Garvey, D.B.; Streets, D.G.; Kotecki, R.; Senew, M.

    1979-10-01

    In accordance with the 1977 Clean Air Act Amendments, EPA established regulations governing new and existing sources of emissions in areas where the NAAQS are being exceeded. These requirements may constrain the implementation of a national energy policy to increase the use of coal in utilities and industries. The states designated the nonattainment areas and prepared State Implementation Plans, outlining strategies for attaining the standards by the deadline of December 31, 1982. This report contains maps of nonattainment areas for all pollutants and summaries of the attainment strategies for those pollutants most likely to affect fossil-fueled energy development - SO/sub 2/, TSP, and NO/sub x/. The review of SIPs indicates that attainment of SO/sub 2/ standards should be relatively easy. Attainment of TSP standards may be more difficult since point sources are already well controlled and further reductions in emissions will require controls on fugitive sources. NO/sub x/ nonattainment is currently limited to three small areas. The report also contains an examination of emission limitations in nonattainment areas and a national assessment of the potential constraints of nonattainment on energy development in 1985 to 1990. The assessment concludes that constraints on projected new coal-fired utilities should not be significant. Constraints on expanded industrial coal use from TSP nonattainment may be significant but the effects of SO/sub 2/ nonattainment should be limited.

  5. ASME N511-19XX, Standard for periodic in-service testing of nuclear air treatment, heating, ventilating and air conditioning systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-08-01

    A draft version of the Standard is presented in this document. The Standard covers the requirements for periodic in-service testing of nuclear safety-related air treatment, heating, ventilating, and air conditioning systems in nuclear facilities. The Standard provides a basis for the development of test programs and does not include acceptance criteria, except in cases where the results of one test influence the performance of other tests. The Standard covers general inspection and test requirements, reference values, inspection and test requirements, generic tests, acceptance criteria, in-service test requirements, testing following an abnormal incident, corrective action requirements, and quality assurance. Mandatory appendices provide a visual inspection checklist and four test procedures. Non-mandatory appendices provide additional information and guidance on mounting frame pressure leak test procedure, corrective action, challenge gas substitute selection criteria, and test program development. 8 refs., 10 tabs.

  6. Nevada Test Site National Emission Standards for Hazardous Air Pollutants Calendar Year 2007

    Energy Technology Data Exchange (ETDEWEB)

    Robert Grossman; Ronald Warren

    2008-06-01

    The Nevada Test Site (NTS) is operated by the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office. From 1951 through 1992, the NTS was operated as the nation's site for nuclear weapons testing. The release of man-made radionuclides from the NTS as a result of testing activities has been monitored since the first decade of atmospheric testing. After 1962, when nuclear tests were conducted only underground, the radiation exposure to the public surrounding the NTS was greatly reduced. After the 1992 moratorium on nuclear testing, radiation monitoring on the NTS focused on detecting airborne radionuclides which come from historically contaminated soils resuspended into the air (e.g., by winds) and tritium-contaminated soil moisture emitted to the air from soils through evapotranspiration. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations [CFR] Part 61 Subpart H) limits the release of radioactivity from a U.S. Department of Energy facility (e.g., the NTS) to 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This is the dose limit established for someone living off of the NTS from radionuclides emitted to air from the NTS. This limit does not include the radiation doses that members of the public may receive through the intake of radioactive particles unrelated to NTS activities, such as those that come from naturally occurring elements in the environment (e.g., naturally occurring radionuclides in soil or radon gas from the earth or natural building materials), or from other man-made sources (e.g., medical treatments). The NTS demonstrates compliance using environmental measurements of radionuclide air concentrations at critical receptor locations. This method was approved by the U.S. Environmental Protection Agency for use on the NTS in 2001 and has been the

  7. Ozone flux to vegetation and its relationship to plant response and ambient air quality standards

    Science.gov (United States)

    Musselman, Robert C.; Massman, William J.

    The National Ambient Air Quality Standard (NAAQS) for ozone is based on occurrences of the maximum 8 h average ambient ozone concentration. However, biologists have recommended a cumulative ozone exposure parameter to protect vegetation. In this paper we propose a third alternative which uses quantifiable flux-based numerical parameters as a replacement for cumulative ambient parameters. Herein we discuss the concept of ozone flux as it relates to plant response and the NAAQS, and document information needed before a flux-based ozone NAAQS for vegetation can be implemented. Additional research is needed in techniques for determining plant uptake and in the quantification of plant defensive mechanisms to ozone. Models which include feedback mechanisms should be developed to relate ozone flux, loading, and detoxification with photosynthesis and plant productivity.

  8. Air index compensated interferometer as a prospective novel primary standard for baseline calibrations

    International Nuclear Information System (INIS)

    We describe the status of the development of an interferometer for absolute distance measurements with an intrinsic compensation of the refractive index of air, intended as a primary standard for the calibration of geodetic baselines. Two frequency-doubled Nd:YAG lasers are offset locked with a frequency difference of ≈20 GHz at the infrared 1064 nm fundamental wavelength. The resulting synthetic wavelengths of 15 mm for the infrared and 7.5 mm for the frequency-doubled green light are used as the scale for the measurements. Longer synthetic wavelengths are generated by acousto-optic frequency shifters. Based on the dispersion in air between green and infrared light the refractive index can be compensated. The attempt is demanding since uncertainties of the interferometric measurements for the optical wavelengths are scaled by a factor of nearly 300 000 in the refractive index compensated result. First comparisons up to 50 m length between this interferometer and a HeNe reference are presented. The deviations are smaller than ± 200 µm and dominated by a non-linearity from problems in the collimation of the measurement beams. In the linear parts the deviations are below ± 100 µm. (paper)

  9. Establishment of soft x-ray reference fields for performance tests of radiation measuring instruments based on national standard

    International Nuclear Information System (INIS)

    In the Japanese Industrial Standard, JIS Z 4511 sets the condition of X-ray reference fields to be used for the performance test of radiation measuring instruments for radiation protection. With the soft X-ray generator installed in the Facility of Radiation Standards in Nuclear Science Research Institute, we have established four series of soft X-ray reference fields with quality index of 0.6, 0.7, 0.8 and 0.9 based on JIS Z 4511. In this article, quality of the X-ray fields, X-ray spectra, conversion coefficients to the dose equivalents from Air-Kerma were evaluated in the soft X-ray fields produced with X-ray tube voltage ranging from 6 kV to 100 kV, and set soft X-ray reference fields based on Japanese Industrial Standard about 42 qualities. As a result, this X-ray reference fields met a domestic setting condition well and precision was good for conversion factors to various dose equivalents from Air- Kerma and we confirmed the soundness of the spectrum of each X-ray quality. By this, it is found that dose equivalent standard with good precision and wide range of test energy points and dose rates can be provided, for the performance tests such as the energy characteristic and the direction characteristic for various radiation instruments. (author)

  10. National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions Calendar Year 2012

    Energy Technology Data Exchange (ETDEWEB)

    Warren, R.

    2013-06-10

    The U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) operates the Nevada National Security Site (NNSS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NNSS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NNSS activities has been monitored since the initiation of atmospheric testing. Limitation to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NNSS. After nuclear testing ended in 1992, NNSS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of legacy-related tritium are also emitted to air at the NLVF, an NNSS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations [CFR] Part 61 Subpart H) (CFR 2010a) limits the release of radioactivity from a U.S. Department of Energy (DOE) facility to that which would cause 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation unrelated to NNSS activities. Unrelated doses could come from naturally occurring radioactive elements, from sources such as medically or commercially used radionuclides, or from sources outside of the United States, such as the damaged Fukushima nuclear power plant in Japan in 2011. NNSA/NFO demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations on the NNSS (U.S. Environmental Protection Agency [EPA] and DOE 1995). This method was approved by the EPA for use on the NNSS in 2001 (EPA 2001a) and has

  11. National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions Calendar Year 2013

    Energy Technology Data Exchange (ETDEWEB)

    Warren, R.

    2014-06-04

    The U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) operates the Nevada National Security Site (NNSS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NNSS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NNSS activities has been monitored since the initiation of atmospheric testing. Limitations to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NNSS. After nuclear testing ended in 1992, NNSS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of legacy-related tritium are also emitted to air at the NLVF, an NNSS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations [CFR] Part 61 Subpart H) (CFR 2010a) limits the release of radioactivity from a U.S. Department of Energy (DOE) facility to that which would cause 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation unrelated to NNSS activities. Unrelated doses could come from naturally occurring radioactive elements, from sources such as medically or commercially used radionuclides, or from sources outside of the United States, such as the damaged Fukushima nuclear power plant in Japan in 2011. NNSA/NFO demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations on the NNSS (U.S. Environmental Protection Agency [EPA] and DOE 1995). This method was approved by the EPA for use on the NNSS in 2001 (EPA 2001a) and has

  12. National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions, Calendar Year 2011

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Ecological and Environmental Monitoring

    2012-06-19

    The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office operates the Nevada National Security Site (NNSS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NNSS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NNSS activities has been monitored since the initiation of atmospheric testing. Limitation to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NNSS. After nuclear testing ended in 1992, NNSS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of legacy-related tritium are also emitted to air at the NLVF, an NNSS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations [CFR] Part 61 Subpart H) limits the release of radioactivity from a U.S. Department of Energy (DOE) facility to that which would cause 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation unrelated to NNSS activities. Unrelated doses could come from naturally occurring radioactive elements, from sources such as medically or commercially used radionuclides, or from sources outside of the United States, such as the damaged Fukushima nuclear power plant in Japan. Radionuclides from the Fukushima nuclear power plant were detected at the NNSS in March 2011 and are discussed further in Section III. The NNSS demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations. This method was approved by the EPA for use on the

  13. National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions Calendar Year 2009

    International Nuclear Information System (INIS)

    The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office operates the Nevada Test Site (NTS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NTS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NTS activities has been monitored since the initiation of atmospheric testing. Limitation to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NTS. After nuclear testing ended in 1992, NTS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of tritium were also emitted to air at the NLVF, an NTS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations (CFR) Part 61 Subpart H) limits the release of radioactivity from a U.S. Department of Energy facility to 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation not related to NTS activities. Unrelated doses could come from naturally occurring radioactive elements or from sources such as medically or commercially used radionuclides. The NTS demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations. This method was approved by the U.S. Environmental Protection Agency for use on the NTS in 2001 and has been the sole method used since 2005. Six locations on the NTS have been established to act as critical receptor locations to demonstrate compliance with the NESHAP limit. These locations are actually pseudo-critical receptor stations, because no

  14. Nevada Test Site National Emission Standards for Hazardous Air Pollutants Calendar Year 2008

    Energy Technology Data Exchange (ETDEWEB)

    Ronald Warren and Robert F. Grossman

    2009-06-30

    The Nevada Test Site (NTS) is operated by the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office. From 1951 through 1992, the NTS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NTS activities has been monitored since the initiation of atmospheric testing. Limitation to under-ground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NTS. After nuclear testing ended in 1992, NTS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by winds) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of tritium were also emitted to air at the North Las Vegas Facility (NLVF), an NTS support complex in the city of North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations [CFR] Part 61 Subpart H) (CFR, 2008a) limits the release of radioactivity from a U.S. Department of Energy facility (e.g., the NTS) to 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation not related to NTS activities. Unrelated doses could come from naturally occurring radioactive elements or from other man-made sources such as medical treatments. The NTS demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations. This method was approved by the U.S. Environmental Protection Agency for use on the NTS in 2001 and has been the sole method used since 2005. Six locations on the NTS have been established to act as critical receptor locations to demonstrate compliance with the NESHAP limit. These locations are actually pseudo

  15. Nevada Test Site National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions Calendar Year 2008

    International Nuclear Information System (INIS)

    The Nevada Test Site (NTS) is operated by the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office. From 1951 through 1992, the NTS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NTS activities has been monitored since the initiation of atmospheric testing. Limitation to under-ground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NTS. After nuclear testing ended in 1992, NTS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by winds) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of tritium were also emitted to air at the North Las Vegas Facility (NLVF), an NTS support complex in the city of North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations (CFR) Part 61 Subpart H) (CFR, 2008a) limits the release of radioactivity from a U.S. Department of Energy facility (e.g., the NTS) to 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation not related to NTS activities. Unrelated doses could come from naturally occurring radioactive elements or from other man-made sources such as medical treatments. The NTS demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations. This method was approved by the U.S. Environmental Protection Agency for use on the NTS in 2001 and has been the sole method used since 2005. Six locations on the NTS have been established to act as critical receptor locations to demonstrate compliance with the NESHAP limit. These locations are actually pseudo

  16. CITY DEVELOPMENT FOR KEEPING POLLUTANT CONCENTRATIONS FROM MOTOR VEHICLES IN RESIDENTIAL AREAS IN ACCORDANCE WITH AIR QUALITY STANDARDS

    OpenAIRE

    Владимир Васильевич Балакин

    2016-01-01

    The dependency of carbon monoxide concentrations on wind speed has been obtained in the field studies. It is used in determining optimum ventilation modes for street space to ensure keeping the content of the toxic components from automobile exhaust in accordance with public health standards.Environmental basis for development optimization for busy primary streets has been provided to avoid dangerous levels of ambient air pollution with automobile emissions.Positive effect on air quality from...

  17. A spatial cost-effectiveness study of transport policy measures aimed iat achieving air quality standards in the European Union.

    OpenAIRE

    Degraeve, Zeger; Koopman, GJ; Denis, C.; Teunen, L

    1996-01-01

    This paper develops a methodology to select a least cost mix of policy measures in different regions of the European Union to reach air quality standards by the year 2010. Two fundamental characteristics of air quality problems in Europe are addressed : their variation across regions and the interregional linkages induced by ozone. We answer the questions which policies should be introduced where in order to arrive at a least cost solution for the Union as a whole satisfying the emission redu...

  18. SU-E-I-53: Comparison of Kerma-Area-Product Between the Micro-Angiographic Fluoroscope (MAF) and a Flat Panel Detector (FPD) as Used in Neuro-Endovascular Procedures

    International Nuclear Information System (INIS)

    Purpose: To determine the reduction of integral dose to the patient when using the micro-angiographic fluoroscope (MAF) compared to when using the standard flat-panel detector (FPD) for the techniques used during neurointerventional procedures. Methods: The MAF is a small field-of-view, high resolution x-ray detector which captures 1024 x 1024 pixels with an effective pixel size of 35μm and is capable of real-time imaging up to 30 frames per second. The MAF was used in neuro-interventions during those parts of the procedure when high resolution was needed and the FPD was used otherwise. The technique parameters were recorded when each detector was used and the kerma-area-product (KAP) per image frame was determined. KAP values were calculated for seven neuro interventions using premeasured calibration files of output as a function of kVp and beam filtration and included the attenuation of the patient table for the frontal projections to be more representative of integral patient dose. The air kerma at the patient entrance was multiplied by the beam area at that point to obtain the KAP values. The ranges of KAP values per frame were determined for the range of technique parameters used during the clinical procedures. To appreciate the benefit of the higher MAF resolution in the region of interventional activity, DA technique parameters were generally used with the MAF. Results: The lowest and highest values of KAP per frame for the MAF in DA mode were 4 and 50 times lower, respectively, compared to those of the FPD in pulsed fluoroscopy mode. Conclusion: The MAF was used in those parts of the clinical procedures when high resolution and image quality was essential. The integral patient dose as represented by the KAP value was substantially lower when using the MAF than when using the FPD due to the much smaller volume of tissue irradiated. This research was supported in part by Toshiba Medical Systems Corporation and NIH Grant R01EB002873

  19. SU-E-I-53: Comparison of Kerma-Area-Product Between the Micro-Angiographic Fluoroscope (MAF) and a Flat Panel Detector (FPD) as Used in Neuro-Endovascular Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Vijayan, S; Rana, V; Nagesh, S Setlur; Xiong, Z; Rudin, S; Bednarek, D [Toshiba Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY (United States)

    2015-06-15

    Purpose: To determine the reduction of integral dose to the patient when using the micro-angiographic fluoroscope (MAF) compared to when using the standard flat-panel detector (FPD) for the techniques used during neurointerventional procedures. Methods: The MAF is a small field-of-view, high resolution x-ray detector which captures 1024 x 1024 pixels with an effective pixel size of 35μm and is capable of real-time imaging up to 30 frames per second. The MAF was used in neuro-interventions during those parts of the procedure when high resolution was needed and the FPD was used otherwise. The technique parameters were recorded when each detector was used and the kerma-area-product (KAP) per image frame was determined. KAP values were calculated for seven neuro interventions using premeasured calibration files of output as a function of kVp and beam filtration and included the attenuation of the patient table for the frontal projections to be more representative of integral patient dose. The air kerma at the patient entrance was multiplied by the beam area at that point to obtain the KAP values. The ranges of KAP values per frame were determined for the range of technique parameters used during the clinical procedures. To appreciate the benefit of the higher MAF resolution in the region of interventional activity, DA technique parameters were generally used with the MAF. Results: The lowest and highest values of KAP per frame for the MAF in DA mode were 4 and 50 times lower, respectively, compared to those of the FPD in pulsed fluoroscopy mode. Conclusion: The MAF was used in those parts of the clinical procedures when high resolution and image quality was essential. The integral patient dose as represented by the KAP value was substantially lower when using the MAF than when using the FPD due to the much smaller volume of tissue irradiated. This research was supported in part by Toshiba Medical Systems Corporation and NIH Grant R01EB002873.

  20. Determination of the effect of transfer between vacuum and air on mass standards of platinum-iridium and stainless steel

    Science.gov (United States)

    Davidson, Stuart

    2010-08-01

    This paper reports work undertaken to assess the change in the mass values of stainless steel and platinum-iridium weights transferred between air and vacuum and to determine the repeatability of this change. Sets of kilogram transfer standards, manufactured from stainless steel and platinum-iridium and with different surface areas, were used to determine the effect of transfer between air and vacuum on the values of the mass standards. The SI unit of mass is the only unit of the seven base SI quantities which is still defined in terms of an artefact rather than by relation to a fundamental physical constant. Work is underway to identify a means of deriving the SI unit of mass from fundamental constants and at present the two principal approaches are the International Avogadro Coordination and the watt balance projects. Both of these approaches involve realizing a kilogram in vacuum and therefore the traceability from a kilogram realized in vacuum to mass standards in air is crucial to the effective dissemination of the mass scale. The work reported here characterizes the changes in mass values of standards on transfer between air and vacuum and thus will enable traceability to be established for an in-air mass scale based on a definition of the unit in vacuum.

  1. Exceedances of air quality standard level of PM2.5 in Japan caused by Siberian wildfires

    International Nuclear Information System (INIS)

    We revisited long-term observations of PM2.5 at ground-based stations in Japan during 2001–2012 to examine possible impacts of Siberian wildfires on regional air quality. Exceedances of Japan’s air quality standard for daily mean concentration (35 μg m−3) were observed several times at Rishiri Island in northern Japan in the spring of 2003 and 2008 when intense wildfires occurred in Siberia. Satellite observations showed that aerosols and CO originating from biomass burning were transported from Siberia toward Japan. The regional chemical transport model also demonstrated that the PM2.5 enhancements during high PM2.5 days (>35 μg m−3) were attributed to Siberian wildfires, suggesting that the contribution from Siberian biomass burning had a critical impact on exceedances of air quality standard level. The monthly (May) and annual mean PM2.5 concentrations in 2003 were about twice and 20% higher, respectively, than those of the long-term average at Rishiri Island, where the influence of Siberian wildfires was the largest in Japan. Except for 2003 and 2008, a high PM2.5 day due to Siberian wildfires was not identified. Although Siberian biomass burning does not affect the air quality standard of PM2.5 for the years without strong fires, it causes exceedance of the air quality standard level when intense fires occur. (letter)

  2. Calibration in medical diagnostic beams at the Swedish secondary standard dosimetry laboratory

    International Nuclear Information System (INIS)

    New diagnostic X-ray beams based on the IEC standard no. 1267 are now available at the Secondary Standard Dosimetry Laboratory in Sweden. These beams are alternatives to the ISO narrow qualities and BIPM qualities that until now have been used for calibration of diagnostic instruments. A procedure differing somewhat from the IEC standard but following the primary radiation standards laboratory at PTB has been used for defining the radiation quality. This report describes the characteristics of the new radiation beams and the estimated effect on calibration factors due to the change in radiation quality. The effect on existing calibration beams due to the reconstruction of filter wheels has been investigated concerning scattered radiation, half-value layers and air kerma rates

  3. Reference and Equivalent Methods Used to Measure National Ambient Air Quality Standards (NAAQS) Criteria Air Pollutants - Volume I

    Science.gov (United States)

    There are a number of Federal Reference Method (FRM) and Federal Equivalent Method (FEM) systems used to monitor the six criteria air pollutants (Lead [Pb], Carbon Monoxide [CO], Sulfur Dioxide [SO2], Nitrogen Dioxide [NO2], Ozone [O3], Particulate Matter [PM]) to determine if an...

  4. 76 FR 80597 - National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...

    Science.gov (United States)

    2011-12-23

    ... hazardous air pollutants (HAP). Waste heat boilers and process heaters and boilers and process heaters that... Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and Process... for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers...

  5. 78 FR 34964 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation...

    Science.gov (United States)

    2013-06-11

    ... Federal Register on June 6, 2013, (78 FR 34178) and is available at: http://www.epa.gov/air/ozonepollution... on June 6, 2013, (78 FR 34178) and is available at http://www.epa.gov/air/ozonepollution/actions.html... AGENCY 40 CFR Parts 50, 51, 70 and 71 Implementation of the 2008 National Ambient Air Quality...

  6. 77 FR 38889 - National Ambient Air Quality Standards for Particulate Matter

    Science.gov (United States)

    2012-06-29

    ... the original air quality criteria document (DHEW, 1969; 36 FR 8186, April 30, 1971). The reference... plans for the next periodic review of the air quality criteria and NAAQS for PM (62 FR 55201, October 23... respect to visual air quality. The EPA solicits comment on all aspects of the proposed secondary...

  7. 78 FR 54432 - Development of Inward Leakage Standards for Half-Mask Air-Purifying Particulate Respirators

    Science.gov (United States)

    2013-09-04

    ... inward leakage performance requirements for the class of NIOSH-certified non-powered air-purifying... the identified topics of specific interest are included in this document. Attendance at the public... inward leakage performance standards for the class of NIOSH-certified, non-powered...

  8. 76 FR 76972 - Release of Final Integrated Review Plan for the National Ambient Air Quality Standards for Lead

    Science.gov (United States)

    2011-12-09

    ... available for public comment (76 FR 20347). The final IRP announced today has been prepared after... was issued on February 26, 2010 (75 FR 8934). Dated: December 5, 2011. Mary E. Henigin, Acting... AGENCY Release of Final Integrated Review Plan for the National Ambient Air Quality Standards for...

  9. 77 FR 21690 - Approval and Promulgation of Air Quality Implementation Plan for 1997 8-Hour Ozone Standard; Arizona

    Science.gov (United States)

    2012-04-11

    ... lung disease. Ozone exposure also increases the risk of premature death from heart or lung disease... document, ``we'', ``us'' and ``our'' refer to EPA. I. The 1997 8-Hour Ozone Standard and the Phoenix-Mesa..., particularly in children and adults with lung disease. Breathing air containing ozone can reduce lung...

  10. Inter-laboratory comparison study on measuring semi-volatile organic chemicals in standards and air samples

    Energy Technology Data Exchange (ETDEWEB)

    Su Yushan, E-mail: yushan.su@ec.gc.c [Air Quality Research Division, Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4 (Canada); Hung, Hayley, E-mail: hayley.hung@ec.gc.c [Air Quality Research Division, Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4 (Canada)

    2010-11-15

    Measurements of semi-volatile organic chemicals (SVOCs) were compared among 21 laboratories from 7 countries through the analysis of standards, a blind sample, an air extract, and an atmospheric dust sample. Measurement accuracy strongly depended on analytes, laboratories, and types of standards and samples. Intra-laboratory precision was generally good with relative standard deviations (RSDs) of triplicate injections <10% and with median differences of duplicate samples between 2.1 and 22%. Inter-laboratory variability, measured by RSDs of all measurements, was in the range of 2.8-58% in analyzing standards, and 6.9-190% in analyzing blind sample and air extract. Inter-laboratory precision was poorer when samples were subject to cleanup processes, or when SVOCs were quantified at low concentrations. In general, inter-laboratory differences up to a factor of 2 can be expected to analyze atmospheric SVOCs. When comparing air measurements from different laboratories, caution should be exercised if the data variability is less than the inter-laboratory differences. - Inter-laboratory differences up to a factor of 2 can be expected for air measurements of semi-volatile organic chemicals.

  11. Inter-laboratory comparison study on measuring semi-volatile organic chemicals in standards and air samples

    International Nuclear Information System (INIS)

    Measurements of semi-volatile organic chemicals (SVOCs) were compared among 21 laboratories from 7 countries through the analysis of standards, a blind sample, an air extract, and an atmospheric dust sample. Measurement accuracy strongly depended on analytes, laboratories, and types of standards and samples. Intra-laboratory precision was generally good with relative standard deviations (RSDs) of triplicate injections <10% and with median differences of duplicate samples between 2.1 and 22%. Inter-laboratory variability, measured by RSDs of all measurements, was in the range of 2.8-58% in analyzing standards, and 6.9-190% in analyzing blind sample and air extract. Inter-laboratory precision was poorer when samples were subject to cleanup processes, or when SVOCs were quantified at low concentrations. In general, inter-laboratory differences up to a factor of 2 can be expected to analyze atmospheric SVOCs. When comparing air measurements from different laboratories, caution should be exercised if the data variability is less than the inter-laboratory differences. - Inter-laboratory differences up to a factor of 2 can be expected for air measurements of semi-volatile organic chemicals.

  12. Workshop in Support of the Secondary National Ambient Air Quality Standards for Nitrogen (NOx) and Sulfur Oxides (SOx)

    Science.gov (United States)

    EPA is announcing a workshop to discuss policy-relevant science to Inform EPA’s "Review of the Secondary National Ambient Air Quality Standards (NAAQS) for Oxides of Nitrogen and Sulfur" report. The workshop is being organized by EPA’s Office of Research and Development’s, Nation...

  13. 75 FR 20595 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-04-20

    ...The EPA is announcing an extension of the public comment period for a draft assessment document titled, Policy Assessment for the Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur: First External Review Draft (75 FR 11877; March 12, 2010). The comment period was originally scheduled to end on April 29, 2010. The extended comment period......

  14. Basis to demonstrate compliance with the National Emission Standards for Hazardous Air Pollutants for the Stand-off Experiments Range

    Energy Technology Data Exchange (ETDEWEB)

    Michael Sandvig

    2011-01-01

    The purpose of this report is to provide the basis and the documentation to demonstrate general compliance with the National Emission Standard for Hazardous Air Pollutants (NESHAPS) 40 CFR 61 Subpart H, “National Emission Standards for Emissions of Radionuclides Other Than Radon from Department of Energy Facilities,” (the Standard) for outdoor linear accelerator operations at the Idaho National Laboratory (INL) Stand-off Experiments Range (SOX). The intent of this report is to inform and gain acceptance of this methodology from the governmental bodies regulating the INL.

  15. Technical comments on EPA`s proposed revisions to the National Ambient Air Quality Standard for particulate matter

    Energy Technology Data Exchange (ETDEWEB)

    Lipfert, F.W.

    1997-03-01

    The US Environmental Protection Agency (EPA) has proposed new ambient air quality standards specifically for fine particulate matter, regulating concentrations of particles with median aerodynamic diameters less than 2.5 {mu}m (PM{sub 2.5}). Two new standards have been proposed: a maximum 24-hr concentration that is intended to protect against acute health effects, and an annual concentration limit that is intended to protect against longer-term health effects. EPA has also proposed a slight relaxation of the 24-hr standard for inhalable particles (PM{sub 10}), by allowing additional exceedances each year. Fine particles are currently being indirectly controlled by means of regulations for PM{sub 10} and TSP, under the Clean Air Act of 1970 and subsequent amendments. Although routine monitoring of PM{sub 2.5} is rare and data are sparse, the available data indicate that ambient concentrations have been declining at about 6% per year under existing regulations.

  16. Studies on effective atomic number, electron density and kerma for some fatty acids and carbohydrates

    DEFF Research Database (Denmark)

    Manohara, S.R.; Hanagodimath, S.M.; Gerward, Leif

    2008-01-01

    XCom program. The significant variation of Z(eff) and N-el is due to the variations in the dominance of different interaction processes in different energy regions. The maximum values of Z(eff) and N-el are found in the low-energy range, where photoelectric absorption is the main interaction process. The...... also made with the single values of the Z(eff) and N-el provided by the program XMuDat. It is also observed that carbohydrates have a larger kerma than fatty acids in the low-energy region, where photoelectric absorption dominates. In contrast, fatty acids have a larger kerma than carbohydrates in the...

  17. Studies on mass attenuation coefficient, mass energy absorption coefficient and kerma of some vitamins

    International Nuclear Information System (INIS)

    Highlights: ► Kerma is essential for nuclear medicine, diagnostics and radiation dosimeter. ► The values of μm and μe/ρ depends on the photon energy and chemical content of vitamins. ► New experiments should be performed to study physical parameters of biomolecules. -- Abstract: The mass attenuation coefficients for some vitamins (retinol, beta-carotene, thiamine, riboflavin, niacinamide, pantothenic acid, pyridoxine, biotin, folic acid, cyanocobalamin, ascorbic acid, cholecalciferol, alpha-tocopherol, ketamine, hesperidin) were determined experimentally and theoretically at 356.61, 661.66, 1250 and 1408.01 keV photon energies by using a NaI(Tl) scintillation detector. Also, the mass energy absorption coefficients and kerma have been calculated. The calculated values were compared with the semi-empirical values for vitamins.

  18. Calibration methodology application of kerma area product meters in situ: Preliminary results

    International Nuclear Information System (INIS)

    The kerma-area product (KAP) is a useful quantity to establish the reference levels of conventional X-ray examinations. It can be obtained by measurements carried out with a KAP meter on a plane parallel transmission ionization chamber mounted on the X-ray system. A KAP meter can be calibrated in laboratory or in situ, where it is used. It is important to use one reference KAP meter in order to obtain reliable quantity of doses on the patient. The Patient Dose Calibrator (PDC) is a new equipment from Radcal that measures KAP. It was manufactured following the IEC 60580 recommendations, an international standard for KAP meters. This study had the aim to calibrate KAP meters using the PDC in situ. Previous studies and the quality control program of the PDC have shown that it has good function in characterization tests of dosimeters with ionization chamber and it also has low energy dependence. Three types of KAP meters were calibrated in four different diagnostic X-ray equipments. The voltages used in the two first calibrations were 50 kV, 70 kV, 100 kV and 120 kV. The other two used 50 kV, 70 kV and 90 kV. This was related to the equipments limitations. The field sizes used for the calibration were 10 cm, 20 cm and 30 cm. The calibrations were done in three different cities with the purpose to analyze the reproducibility of the PDC. The results gave the calibration coefficient for each KAP meter and showed that the PDC can be used as a reference instrument to calibrate clinical KAP meters. - Highlights: • The Patient Dose Calibrator (PDC) is a new equipment from Radcal that measures KAP. • This study aimed the calibration of KAP meters in situ using the PDC as a reference. • The method used for the calibration of the KAP meters was the tandem method. • This instrument calculates the dose that the patient receives during an X-ray examination. • The calibration procedure is important to correct the measurements performed with KAP meters

  19. Calculated neutron KERMA factors based on the LLNL ENDL data file. Volume 27

    International Nuclear Information System (INIS)

    Neutron KERMA factors calculated from the LLNL ENDL data file are tabulated for 15 composite materials and for the isotopes or elements in the ENDL file from Z = 1 to Z = 29. The incident neutron energies range from 1.882 x 10-5 to 20. MeV for the composite materials and from 1.30 x 10-9 to 20. MeV for the isotopes and elements

  20. A simple device for the measurement of kerma based on commercial PIN photo diodes

    Czech Academy of Sciences Publication Activity Database

    Kushpil, Vasilij; Kushpil, Svetlana; Huňa, Zdeněk

    Cedex: EDP Sciences, 2012, s. 1-9. ISBN 978-88-7438-069-5. ISSN 2100-014X. [International Conference on Environmental Radioactivity - New Frontiers and Developments. Řím (IT), 25.10.2010-27.10.2010] R&D Projects: GA MŠk LC07048 Institutional support: RVO:61389005 Keywords : PIN diode * kerma measurement Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  1. 75 FR 80761 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2010-12-23

    ... Reciprocating Internal Combustion Engines AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of... air pollutants for reciprocating internal combustion engines and requesting public comment on...

  2. OpenAIRE Guidelines for CRIS Managers: Supporting Interoperability of Open Research Information through Established Standards

    DEFF Research Database (Denmark)

    Houssos, Nikos; Jörg, Brigitte; Dvořák, Jan;

    2014-01-01

    OpenAIRE is the European infrastructure enabling researchers to comply with the European Union requirements for Open Access to research results. OpenAIRE collects metadata from data sources across Europe and beyond and defines interoperability guidelines to assist providers in exposing their...... information in a way that is compatible with OpenAIRE. This contribution focuses on a specific type of data source, CRIS systems, and the respective OpenAIRE guidelines, based on CERIF XML. A range of issues, spanning different aspects of information representation and exchange, needed to be addressed by the...

  3. Estimation of Uncertainty of Air Buoyancy Correction for Establishment of Primary Mass Standards

    OpenAIRE

    KAÇMAZ, Sevda

    2000-01-01

    The most accurate value of air density is obtained by a calculation based on the equation using measured atmospheric parameters approved by the International Committee for Weights and Measures in 1981. When a 1-kg steel weight was calibrated against the prototype kilogram using the international expression for determining the density of air, experimental results showed that the estimated uncertainty of the air density was 1.45x10-4 mg.cm-3 and the uncertainty of air buoyancy was 11.3 mg.

  4. CITY DEVELOPMENT FOR KEEPING POLLUTANT CONCENTRATIONS FROM MOTOR VEHICLES IN RESIDENTIAL AREAS IN ACCORDANCE WITH AIR QUALITY STANDARDS

    Directory of Open Access Journals (Sweden)

    Владимир Васильевич Балакин

    2016-02-01

    Full Text Available The dependency of carbon monoxide concentrations on wind speed has been obtained in the field studies. It is used in determining optimum ventilation modes for street space to ensure keeping the content of the toxic components from automobile exhaust in accordance with public health standards.Environmental basis for development optimization for busy primary streets has been provided to avoid dangerous levels of ambient air pollution with automobile emissions.Positive effect on air quality from belt roads, bypass roads and pedestrian areas situated in city centers is noted.

  5. 76 FR 54293 - Review of National Ambient Air Quality Standards for Carbon Monoxide

    Science.gov (United States)

    2011-08-31

    ... Act concerning CASAC review of air quality criteria. See 71 FR 61144, 61148 (October 17, 2006) (final... supplement the pertinent air quality criteria so the studies can be taken into account (58 FR at 13013-13014... average, and 35 ppm, as a 1-hour average, neither to be exceeded more than once per year (36 FR 8186)....

  6. A design of brachytherapy source calibration template for air kerma rate/activity measurement

    International Nuclear Information System (INIS)

    This simple template can be used for the purpose of calibration of brachytherapy source, if the department does not have the calibration-track stand. One can design this template in the hospital itself as per the requirement, availability and facility, and the expenses also will be less. It is fully made up of a very thin 0.75 mm thickness of paper cardboard and this is the speciality. Currently this template is being utilized for accurate and easy calibration purposes

  7. Verification of traceability and backscattering in surface entrance air kerma measurements with detector type ionizing chamber

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, G.J.; Peixoto, J.G.P., E-mail: guilherm@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    Measurements of doses in radiology services by ionizing chambers are easier than those made by TLD, however the protocols for measurements differ regarding the calibration. The objectives were to verify the traceability in the measures of ESAK corrected by the inverse square law, due to the difference in position between the source and IC and the influence of the backscattered radiation in bringing the detector to the table. Was defined a procedure practiced by the radiological services and designed experimental arrangements for the same technique. Was noted that the approximation of the detector to the table generated a significant backscattered. (author)

  8. An EGSnrc investigation of cavity theory for ion chambers measuring air kerma

    International Nuclear Information System (INIS)

    The EGSnrc system is used to compare the response of an aluminum-walled thimble chamber to that of a graphite-walled thimble chamber for a 60Co beam. When compared to previous experimental results, the EGSnrc values of the ratios of chamber response differ by as much as 0.7% from the experiment. However, it is shown that this difference can be more than accounted for by switching from using the graphite mean excitation energy of 78 eV used in dosimetry protocols to the value of 86.8 eV suggested by more recent stopping-power experiments. This suggests that the uncertainty analysis of Monte Carlo results must be done more carefully, by taking into account uncertainties in the underlying basic data such as the electron and photon cross sections. In comparison to Spencer-Attix cavity theory for a thick-walled ion chamber, the Monte Carlo calculated values of the chamber response differ from the expected ones by 0.15% and 0.01% for the graphite and aluminum chambers, respectively, which are comparable to previously reported values for the Spencer-Attix correction factors. EGSnrc is also used to investigate the effect on the chamber response of thin dag layers on the inside of the aluminum wall. There is good agreement between the calculated and measured changes in chamber response versus the thickness of the dag. The results are compared to the predictions of the Almond-Svensson extension of cavity theory and show that the theory does not correctly predict the chamber response in the presence of thin dag layers. This finding is in agreement with previously reported experimental results. It is demonstrated that the values of α, the fraction of ionizations in the gas arising from electrons generated in the dag layer, used in the theory, are not the source of the disagreement

  9. 75 FR 27227 - Energy Conservation Program: Energy Conservation Standards for Residential Central Air...

    Science.gov (United States)

    2010-05-14

    ... Part 431 RIN 1904-AB47 Energy Conservation Program: Energy Conservation Standards for Residential... preliminary analyses performed by DOE for these products; and potential energy conservation standard levels... on the energy conservation standards notice of public meeting (NOPM) and availability of...

  10. A review on test procedure, energy efficiency standards and energy labels for room air conditioners and refrigerator-freezers

    Energy Technology Data Exchange (ETDEWEB)

    Mahlia, T.M.I.; Saidur, R. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2010-09-15

    Air conditioners and refrigerator-freezers are major energy users in a household environment and hence efficiency improvement of these appliances can be considered as an important step to reduce their energy consumption along with environmental pollution prevention. Energy efficiency standards and labels are commonly used tools to reduce the energy uses for household appliances for many countries around the world. The first step towards adopting energy efficiency standards is to establish a test procedure for rating and testing of an appliance. It may be mentioned that an energy test procedure is the technical foundation for energy efficiency standards, energy labels, and other related programs. This paper reviews requirements and specifications of various international test standards for testing and rating of room air conditioners and refrigerators. A review on the development of the energy efficiency standards has been provided as well. Finally, energy labels that provide some useful information for identifying energy efficient products have been reviewed for these appliances. It may be stated that the review will be useful for the developing countries who wish to develop these energy savings strategies. It is also expected to be useful to revise the existing strategies for a few selected countries who already implemented these strategies earlier. (author)

  11. Addition of PM2.5 into the National Ambient Air Quality Standards of China and the Contribution to Air Pollution Control: The Case Study of Wuhan, China

    OpenAIRE

    2014-01-01

    PM2.5 has gradually become a major environmental problem of China with its rapid economic development, urbanization, and increasing of motor vehicles. Findings and awareness of serious PM2.5 pollution make the PM2.5 a new criterion pollutant of the Chinese National Ambient Air Quality Standard (NAAQS) revised in 2012. The 2012 NAAQS sets the PM2.5 concentrate limitation with the 24-hour average value and the annual mean value. Wuhan is quite typical among central and southern China in climate...

  12. Estándares para el Sistema de Bibliotecas de la Universidad de Buenos Aires Standards for the Universidad de Buenos Aires Libraries System

    Directory of Open Access Journals (Sweden)

    Elsa Elena Elizalde

    2009-06-01

    Full Text Available La Coordinación General del Sistema de Bibliotecas y de Información -SISBI- de la Universidad de Buenos Aires propuso la conformación de un Grupo de Trabajo para el estudio y la definición de los requerimientos para un adecuado nivel de prestación de los servicios de todas sus bibliotecas. Estos estándares externos completarán y actualizarán los «Lineamientos para una Política Bibliotecaria de la Universidad de Buenos Aires (Resolución CS Nº 222/94». El objetivo del conjunto de criterios que representan estos Estándares para el Sistema de Bibliotecas de la UBA, es que éstas cuenten con una herramienta base que les permita tomar decisiones concernientes a la planificación y administración de los servicios bibliotecarios. Independientemente, se espera que cada Biblioteca defina sus estándares internos de tiempo, calidad, cantidad y costos que reflejen las metas y objetivos de cada Unidad Académica en particular. Estos estándares contemplan: Aspectos organizativos de la Biblioteca Universitaria y Principios Generales del SISBI; Infraestructura Edilicia y Tecnológica; Recursos Humanos; Servicios y/o Productos; Desarrollo de la colección; Procesos Técnicos; Presupuesto; Evaluación y Gestión de la Calidad e Innovación; Prevención y Conservación; entre otros.The General Coordination of the Sistema de Bibliotecas y de Información- SISBI- of the Universidad de Buenos Aires proposed the creation of a Work Group for the study and definition of the requirements for a proper provision level of all libraries services. Those external standards will complement and update the «Guidelines for a Library Policy of the Universidad de Buenos Aires (Resolution N° 222/94». The aim of the whole criteria that represent the Standards for the UBA Libraries System is that they have a basic tool that allow them to take decisions on planning and administration of library services. Separately, it is expected that each Library defines its

  13. Air

    Science.gov (United States)

    ... house) Industrial emissions (like smoke and chemicals from factories) Household cleaners (spray cleaners, air fresheners) Car emissions (like carbon monoxide) *All of these things make up “particle pollution.” They mostly come from cars, trucks, buses, and ...

  14. 77 FR 20217 - Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur

    Science.gov (United States)

    2012-04-03

    ... concentrations of oxides of sulfur and such public welfare effects (38 FR 25679). In 1979, the EPA announced that... 1971. These standards were set at a level of 0.053 parts per million (ppm) as an annual average (36 FR... EPA proposed to retain the standards set in 1971 (49 FR 6866). After taking into account...

  15. Characterization tests of a homemade ionization chamber in mammography standard radiation beams

    International Nuclear Information System (INIS)

    A mammography homemade ionization chamber was developed to be applied for mammography energy range dosimetry. This chamber has a sensitive volume of 6 cm3 and is made of a Lucite body and graphite coated collecting electrode. Characteristics such as saturation, ion collection efficiency, linearity of chamber response versus air kerma rate and energy dependence were determined. The results obtained with the mammography homemade ionization chamber are within the limits stated in international recommendations. This chamber can be used in quality control programs in the diagnostic radiology area. All measurements were carried out at the Calibration Laboratory of IPEN. - Highlights: • We constructed a mammography homemade ionization chamber. It was submitted to standard mammography X-rays beam qualities. • The results obtained showed good agreement with international standards. • This chamber can be used in quality control programs of diagnostic radiology area

  16. Standards for radiation protection and diagnostic radiology at the IAEA Dosimetry Laboratory

    International Nuclear Information System (INIS)

    International standardization in dosimetry is essential for the successful exploitation of radiation technology. The IAEA dosimetry programme is focused into services provided to Member States through the IAEA/WHO Network of Secondary Standard Dosimetry Laboratories (SSDLs), to radiotherapy centres and radiation processing facilities. Radiation protection quantities defined by ICRU and ICRP are used to relate the risk due to exposure to ionizing radiation to a single quantity, irrespective of the type of radiation, which takes into account the human body as a receptor. Two types of quantities, limiting and operational, can be related to basic physical quantities which are defined without need for considering specific aspects of radiation protection, e.g. air kerma for photons and fluence for neutrons. The use of a dosimeter for measurements in radiation protection requires a calibration in terms of a physical quantity together with a conversion from physical into protection quantities by means of a factor or a coefficient

  17. Importance of the neutrons kerma coefficient in the planning of Brachytherapy treatments with Cf-252 sources

    International Nuclear Information System (INIS)

    The Cf-252 is a fast neutrons emitting radioisotope by spontaneous fission that can be used as sealed source in medicine applications, industry and research. Commercially its offer sources of different sizes, compact and with a fast neutrons emission of the order of 106 n/s-μg and an energy spectra that presents respectively maxim and average energy in 2.1 MeV and 0.7 MeV. In medicine new applications are being developed for the treatment of patient with hypoxic and voluminous tumors, where the therapy with photons has not given positive results, as well as for the protocols of therapy treatment by boron neutron capture, where very small sources of Cf-252 will be used with the interstitial brachytherapy technique of high and low dose rate. In this work an analysis of how the small differences that exist in the elementary composition of 4 wicked tumors, 4 ICRU healthy tissues and 3 substitute materials of ICRU tissue used in dosimetry are presented, its generate changes in the neutrons kerma coefficient in function of the energy and consequently in the absorbed dose in the interval of 11 eV to 29 MeV. These differences can produce maximum variations of the neutron kerma coefficients ratio for En > 1 keV of the one: 15% tumor/ICRU guest healthy tissue, 12% ICRU tumor/muscle, 12% ICRU healthy tissues ICRU/ICRU muscle, 22% substitutes tissue/tumor and 22% ICRU substitutes tissue/muscle. Also, it was found that the average value of the neutrons kerma coefficient for the 4 wicked tumors is from 6% to 7% smaller that the average value for the soft tissue in the interval energy of interest for therapy with fast neutrons with En > 1 MeV. These results have a special importance during the planning process of brachytherapy treatments with sources of 252Cf, to optimize and to individualize the patients treatments. (Author)

  18. KAOS-V code: An evaluation tool for neutron kerma factors and other nuclear responses

    International Nuclear Information System (INIS)

    The accurate evaluation of neutron fluence-to-kerma factors from microscopic nuclear data is the subject of this report. The algorithms developed for this purpose combine in a consistent manner the two basic methods for computing kerma factors, namely kinematics and direct energy balance. These algorithms are implemented in the code KAOS-V which was used as the main evaluation tool to construct the response function library KAOS/LIB-V. KAOS-V uses data from the evaluated nuclear data files ENDF/B/V. Auxiliary nuclear data bases, e.g., the Japanese evaluated nuclear data library JENDL-2 can be used as a source of isotopic cross sections when these data are not provided in ENDF/B-V files for a natural element. These are needed mainly to estimate average quantities such as effective Q-values for the natural element. The code has the ability to compare the different results which aids in the choice of a consistent set of algorithms to evaluate kerma factors. Data in ENDF/B-IV and ENDF/B-V format can be processed. For resonance treatment, the code has the ability to access NJOY and NPTXS interface files in formatted or binary forms. No input instructions are necessary to run the code interactively. The user can simply respond to the interactive messages sent by the code if an INPUT file is absent. An INPUT file is automatically generated following an interactive run, and can be edited and used to rerun or produce different results. Grouped and point output data can be produced along with graphic representation. These features are instrumental in detecting and understanding energy balance deficiencies and other problems in the nuclear data files. 60 refs., 4 figs

  19. 77 FR 16987 - National Emission Standards for Hazardous Air Pollutants: Secondary Aluminum Production

    Science.gov (United States)

    2012-03-23

    ... for hazardous air pollutants for secondary aluminum production (77 FR 8576). The EPA is extending the... the proposed rule published February 14, 2012, (77 FR 8576) is being extended for 14 days to April 13... Aluminum Production AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of extension of...

  20. 76 FR 80531 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial...

    Science.gov (United States)

    2011-12-23

    ..., particularly an institution, provides logistical issues with completion of tune-ups on a biennial basis. We are... is not a major source. On March 21, 2011 (76 FR 15554), we issued the NESHAP for industrial.... The EPA implemented this provision in 1999 in the Integrated Urban Air Toxics Strategy, (64 FR...

  1. 49 CFR 571.121 - Standard No. 121; Air brake systems.

    Science.gov (United States)

    2010-10-01

    ... brakes. Antilock brake system or ABS means a portion of a service brake system that automatically... reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the material may be inspected at... control lines and reservoirs that minimizes damage in field operations. Air brake system means a...

  2. Standard specification for high efficiency particulate air filters. Revision No. 2

    International Nuclear Information System (INIS)

    This specification covers the requirements for four types and four sizes of high efficiency particulate air filters, assembled with or without separators and gaskets. Types include Fire Resistant and Moisture Resistant; Hydrogen Fluoride Fume (HF) Resistant; Fire Resistant and Moisture Resistant and Chemical Resistant; and Fire Resistant and Moisture Resistant, High Temperature and High Humidity

  3. 78 FR 7137 - National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...

    Science.gov (United States)

    2013-01-31

    ... effective date revising subpart DDDDD at 76 FR 15451 (March 21, 2011) is lifted January 31, 2013. The... Electrostatic precipitator EPA Environmental Protection Agency FBC Fluidized bed combustion FR Federal Register... Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and...

  4. 77 FR 4522 - National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources

    Science.gov (United States)

    2012-01-30

    .... On October 29, 2009 (74 FR 56008), the EPA issued the NESHAP for the nine chemical manufacturing area... in 1999 in the Integrated Urban Air Toxics Strategy, (64 FR 38715, July 19, 1999) (Strategy... requirement in 2011 (76 FR 15308, March 21, 2011). The chemical manufacturing area source categories...

  5. 76 FR 57913 - Amendments to National Emission Standards for Hazardous Air Pollutants for Area Sources: Plating...

    Science.gov (United States)

    2011-09-19

    ... Air Pollutants for Area Sources: Plating and Polishing'' which was published on June 20, 2011 (76 FR... direct final rule published at 76 FR 35750 on June 20, 2011. ADDRESSES: Docket: All documents in the... (76 FR 35806) published on the same day as a direct final rule, EPA will not institute a...

  6. Consumer life-cycle cost impacts of energy-efficiency standards for residential-type central air conditioners and heat pumps

    International Nuclear Information System (INIS)

    In support of the federal government's efforts to raise the minimum energy-efficiency standards for residential-type central air conditioners and heat pumps, a consumer life-cycle cost (LCC) analysis was conducted to demonstrate the economic impacts on individual consumers from revisions to the standards. LCC is the consumer's cost of purchasing and installing an air conditioner or heat pump and operating the unit over its lifetime. The LCC analysis is conducted on a nationally representative sample of air conditioner and heat pump consumers resulting in a distribution of LCC impacts showing the percentage of consumers that are either benefiting or being burdened by increased standards. Relative to the existing minimum efficiency standard of 10 SEER, the results show that a majority of split system air conditioner and heat pump consumers will either benefit or be insignificantly impacted by increased efficiency standards of up to 13 SEER

  7. A guide for determining compliance with the Clean Air Act Standards for radionuclide emissions from NRC-licensed and non-DOE federal facilities (Rev. 1)

    International Nuclear Information System (INIS)

    The Environmental Protection Agency (EPA) issued standards under Section 112 of the Clean Air Act of February 6, 1985 that limit airborne emissions of radionuclides to the atmosphere. In February 1989 these standards were re proposed , and in November 1989 final standards may be promulgated. This document provides guidance for determining compliance with one of the National Emissions for Hazardous Air Pollutants covering facilities that are licensed by NRC, and federal facilities not operated by the DOE, that could emit radionuclides to the air

  8. Determination of the kerma factors for 14-MeV neutrons in TEP, C, Mg, and Fe

    International Nuclear Information System (INIS)

    Kerma factors, defined as kerma per unit neutron fluence, for 14 MeV D-T neutrons in tissue equivalent plastic, C, Mg and Fe were determined in this work. Rossi-type TEP, C, Mg and Fe walled proportional counters filled with propane-based tissue-equivalent gas and Ar gas at low pressure were employed to measure the energy deposition in the counters. Based upon the concept of Crossers, Insiders, Starters and Stoppers (CISS) developed by Caswell, a theoretical model was used for the analysis of energy deposition in spherical detectors. Because of the detailed analyses the uncertainties in the kerma factors as obtained in this work are evaluated to be between 8 to 11% which are significantly lower than those reported previously for experimental measurements

  9. Progress towards Managing Residential Electricity Demand: Impacts of Standards and Labeling for Refrigerators and Air Conditioners in India

    Energy Technology Data Exchange (ETDEWEB)

    McNeil, Michael A.; Iyer, Maithili

    2009-05-30

    The development of Energy Efficiency Standards and Labeling (EES&L) began in earnest in India in 2001 with the Energy Conservation Act and the establishment of the Indian Bureau of Energy Efficiency (BEE). The first main residential appliance to be targeted was refrigerators, soon to be followed by room air conditioners. Both of these appliances are of critical importance to India's residential electricity demand. About 15percent of Indian households own a refrigerator, and sales total about 4 million per year, but are growing. At the same time, the Indian refrigerator market has seen a strong trend towards larger and more consumptive frost-free units. Room air conditioners in India have traditionally been sold to commercial sector customers, but an increasing number are going to the residential sector. Room air conditioner sales growth in India peaked in the last few years at 20percent per year. In this paper, we perform an engineering-based analysis using data specific to Indian appliances. We evaluate costs and benefits to residential and commercial sector consumers from increased equipment costs and utility bill savings. The analysis finds that, while the BEE scheme presents net benefits to consumers, there remain opportunities for efficiency improvement that would optimize consumer benefits, according to Life Cycle Cost analysis. Due to the large and growing market for refrigerators and air conditioners in India, we forecast large impacts from the standards and labeling program as scheduled. By 2030, this program, if fully implemented would reduce Indian residential electricity consumption by 55 TWh. Overall savings through 2030 totals 385 TWh. Finally, while efficiency levels have been set for several years for refrigerators, labels and MEPS for these products remain voluntary. We therefore consider the negative impact of this delay of implementation to energy and financial savings achievable by 2030.

  10. Information draft on the development of air standards for n-heptane

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    Heptane is a colourless, volatile, flammable liquid with nine isomers, the most common being n-heptane, which has a paraffinic odour. It is an ingredient in gasoline, rubber solvents, naphtha and other petroleum solvents. It occurs almost entirely in the vapour phase, where it is degraded primarily by reaction with photochemically-produced hydroxyl radicals. Short-term exposure to n-heptane at relatively low concentration resulted in vertigo and loss of coordination. Exposure to high concentration for less than 40 minutes induced prostration and loss of reflexes prior to convulsion and death. Average ambient air concentration for n-heptane in Ontario between 1988 and 1995 was 0.81 microgram/cubic meter, as measured by Environment Canada. Currently, Ontario does not have air quality criterion for n-heptane. A review of pertinent literature from world-wide sources revealed that only the states of Michigan and New York have developed air quality guidelines specifically for n-heptane, based on occupational exposure. No human or animal data was found to be available to assess the carcinogenicity of this compound. 33 refs., 1 tab., appendix.

  11. ETS levels in hospitality environments satisfying ASHRAE standard 62-1989: "ventilation for acceptable indoor air quality"

    Science.gov (United States)

    Moschandreas, D. J.; Vuilleumier, K. L.

    Prior to this study, indoor air constituent levels and ventilation rates of hospitality environments had not been measured simultaneously. This investigation measured indoor Environmental Tobacco Smoke-related (ETS-related) constituent levels in two restaurants, a billiard hall and a casino. The objective of this study was to characterize ETS-related constituent levels inside hospitality environments when the ventilation rates satisfy the requirements of the ASHRAE 62-1989 Ventilation Standard. The ventilation rate of each selected hospitality environment was measured and adjusted. The study advanced only if the requirements of the ASHRAE 62-1989 Ventilation Standard - the pertinent standard of the American Society of Heating, Refrigeration and Air Conditioning Engineers - were satisfied. The supply rates of outdoor air and occupant density were measured intermittently to assure that the ventilation rate of each facility satisfied the standard under occupied conditions. Six ETS-related constituents were measured: respirable suspended particulate (RSP) matter, fluorescent particulate matter (FPM, an estimate of the ETS particle concentrations), ultraviolet particulate matter (UVPM, a second estimate of the ETS particle concentrations), solanesol, nicotine and 3-ethenylpyridine (3-EP). ETS-related constituent levels in smoking sections, non-smoking sections and outdoors were sampled daily for eight consecutive days at each hospitality environment. This study found that the difference between the concentrations of ETS-related constituents in indoor smoking and non-smoking sections was statistically significant. Differences between indoor non-smoking sections and outdoor ETS-related constituent levels were identified but were not statistically significant. Similarly, differences between weekday and weekend evenings were identified but were not statistically significant. The difference between indoor smoking sections and outdoors was statistically significant. Most

  12. Development of a transfer standard for the measurement of low Rn-222 activity concentration in air

    International Nuclear Information System (INIS)

    A large volume transfer standard has been developed to calibrate commercial radon measurement devices in a homogeneous Rn-222 reference atmosphere. The transfer standard serves for the realization, maintenance and dissemination of the unit Bq/m3 below 1 kBq/m3. The transfer standard consists of a multi-wire impulse ionization chamber, electronic measurement equipment and the corresponding software. The multi-wire impulse ionization chamber is composed of two parallel printed boards. Between the boards, 478 vertical electrode wires are soldered in to include a volume of 10 L. In the dependency of the energy, the α-particles of Rn-222 and the decay products are detected in the active volume of the multi-wire impulse ionization chamber. By means of the measurement software an α-energy spectrum is produced. Via different algorithms, the activity concentration of the Rn-222 reference atmosphere is determined. - Highlights: • Transfer standard with a volume of 10 L developed for Rn-222. • Activity concentration below 1 kBq/m3 measured with low statistical uncertainties. • Calibration conversion with combined relative standard uncertainty of <2% achieved

  13. Preparation of standard mixtures of gas hydrocarbons in air by the diffusion dilution method

    International Nuclear Information System (INIS)

    An original diffusion system able to produce continuously gaseous samples is described. This system can generate samples with concentrations of benzene in air from 0.1 to 1 ppm a reproducible way. The diffusion dilution method used Is also studied. The use of this diffusion system has been extended to the preparation of binary mixtures (benzene-toluene). Whit a secondary dilution device is possible preparing these mixtures over a wide range of concentrations (0.11 to 0.04 ppm for benzene and 0.06 to 0.02 for toluene). (Author) 7 refs

  14. The effects of ambient conditions on the calibration of air flow plate standards

    Directory of Open Access Journals (Sweden)

    Miao Qian

    2013-01-01

    Full Text Available The volume flow rate measured by air flow plate is influenced by the ambient conditions during the calibration. A series of numerical examples are conducted for the relationship and the outcomes demonstrated that the calibration is quite sensitive to the atmospheric pressure and the ambient temperature, but insensitive to relative humidity. The experiment model has been applied to calibration results with wide ranging ambient conditions. In conclusion, the results of this study demonstrate the benefits to calibration data of minimizing the effects of ambient conditions.

  15. 75 FR 51569 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2010-08-20

    ...: Background Information Document. On March 5, 2009 (71 FR 9698), EPA proposed national emission standards for... sources on June 15, 2004 (69 FR 33474). EPA promulgated NESHAP for new and reconstructed stationary RICE... on January 18, 2008 (73 FR 3568). On March 3, 2010, EPA promulgated NESHAP for existing...

  16. 78 FR 54606 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2013-09-05

    ... standards of performance (``NSPS'') for stationary internal combustion engines (ICE) (78 FR 6674). Following... stationary RICE on March 3, 2010, (75 FR 9648) and August 20, 2010 (75 FR 51570). The EPA received petitions... amendments to the RICE NESHAP on January 30, 2013, (78 FR 6674) to address certain issues raised in...

  17. Standard reference data for the air-liquid and vapor-liquid surface tension of benzene

    Czech Academy of Sciences Publication Activity Database

    Součková, Monika; Klomfar, Jaroslav; Pátek, Jaroslav

    2013-01-01

    Roč. 356, October (2013), s. 329-337. ISSN 0378-3812 R&D Projects: GA ČR GA101/09/0010 Institutional support: RVO:61388998 Keywords : benzene * surface tension * experimental data * standard reference data Subject RIV: BJ - Thermodynamics Impact factor: 2.241, year: 2013 http://www.sciencedirect.com/science/article/pii/S0378381213004196

  18. 78 FR 24073 - Reconsideration of Certain New Source Issues: National Emission Standards for Hazardous Air...

    Science.gov (United States)

    2013-04-24

    ... Manufacturing Industry and Standards of Performance for Portland Cement Plants, 78 FR 10014 (February 12, 2013... (MACT) Floor Analysis for Coal- and Oil-fired Electric Utility Steam Generating Units for Final Rule... oil and the rule may not apply depending on the extent of natural gas usage. The EPA proposed that...

  19. 76 FR 14807 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories...

    Science.gov (United States)

    2011-03-18

    ... Oxide X X X X Sterilization Facilities. Q Industrial Process X X X X Cooling Towers. R Gasoline...: Subpart WWWWW--National Emission Standards for Hospital Ethylene Oxide Sterilizers Subpart YYYYY--NESHAP... Manufacturing. TTTTT Primary Magnesium X X X Refining. WWWWW Hospital Ethylene Oxide X X Sterilizers. YYYYY...

  20. 78 FR 37133 - National Emission Standards for Hazardous Air Pollutants From Petroleum Refineries

    Science.gov (United States)

    2013-06-20

    ...) on August 18, 1995 (60 FR 43620). These standards are commonly referred to as the ``Refinery MACT 1... leaks and closed vent system and control devices (see 77 FR 17898). We believe it is appropriate to..., letter to the EPA. As described in detail in the January 6, 2012, proposal (see 77 FR 964), we denied...

  1. 76 FR 72769 - National Emissions Standards for Hazardous Air Pollutants: Mineral Wool Production and Wool...

    Science.gov (United States)

    2011-11-25

    ...-Product Recovery Plants (Benzene NESHAP), (54 FR 38044, September 14, 1989), described in the next...., 100-in-1 million]'' (54 FR 38045). In the second step of the process, the EPA sets the standard at a... considered acceptable.'' 54 FR 38045. We discussed the maximum individual lifetime cancer risk as being...

  2. 77 FR 11390 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories; Nevada

    Science.gov (United States)

    2012-02-27

    ... programs under section 112(l) (see 58 FR 62262). Subpart E was later amended on September 14, 2000 (see 65 FR 55810). Any request for approval under CAA section 112(l) must meet the approval criteria in 112(l... NESHAP and approving NDEP's delegation mechanism for future standards (see 63 FR 28906). That...

  3. Improved free-air ionization chamber for the measurement of X-rays

    International Nuclear Information System (INIS)

    Based on an original design by F. H. Attix, an improved free-air ionization chamber was constructed at the National Radiation Standard Laboratory of the Institute of Nuclear Energy Research (INER, Taiwan), as the primary standard for x-ray generated at energy levels between 50 keV and 300 keV. Various improvements were made to the Attix design, including modifications of the chamber structure and the measurement technique. The changes include: a three-section design with fixed central cylinder; thickening of the shielding box; a circuitous mechanism for the operational handle, to avoid unwanted scattering; a ruler mechanism to provide fine position control; and increased thickness of the aluminium wall of the chamber. After initial experimental verification, a comparison with the National Institute of Standards and Technology (NIST, USA) using a transfer standard chamber yielded differences in calibration factors of less than 1 %. In addition, the overall uncertainty for the x-ray measurement in terms of air kerma is less than 1 % at the 95 % confidence level. These results indicate that the improved free-air ionization chamber can serve as a primary standard at the NRSL. (authors)

  4. Hanford Site radionuclide national emission standards for hazardous air pollutants registered stack source assessment

    International Nuclear Information System (INIS)

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency,, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site . The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified a total of 16 stacks as having potential emissions that,would cause an effective dose equivalent greater than 0.1 mrem/yr

  5. The Study of a Portable Precision Air Enclosure for Preserving Standard Resistor

    International Nuclear Information System (INIS)

    A novel portable precision air enclosure was designed in this paper. Orthogonalization of the coefficients matrix to decouple the all parts of the control system was attained in theory and heating wires were wound on the surface of the aluminum chamber evenly in construction. Foam plastic was placed between outer and aluminum chamber as thermal insulation. The inner space is 300 mmx250 mmx300 mm, where can fit one SR 102 type resistor or two Tinsley 5685 type resistors. The total weight of the enclosure is about 25kg, which is still a portable one. Its outstanding feature is the temperature difference between top and bottom was offset. Experiment result shows that the monthly inner temperature homogeneity and stability of the enclosure are within 2 mK

  6. Hanford Site radionuclide national emission standards for hazardous air pollutants registered stack source assessment

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.E.; Barnett, J.M.

    1994-07-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency,, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site . The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified a total of 16 stacks as having potential emissions that,would cause an effective dose equivalent greater than 0.1 mrem/yr.

  7. Establishment of 6- to 7-MeV high-energy gamma-ray calibration fields produced using the 4-MV Van de Graaff accelerator at the Facility of Radiation Standards, Japan Atomic Energy Agency.

    Science.gov (United States)

    Kowatari, Munehiko; Tanimura, Yoshihiko

    2016-03-01

    A 6- to 7-MeV high-energy gamma-ray field, produced by the nuclear reaction of (19)F(p, αγ)(16)O, has been established at the Facility of Radiation Standards (FRS) in Japan Atomic Energy Agency for calibration purposes. Basic dosimetric quantities (i.e. averaged gamma-ray energy, air-kerma-to-dose equivalent conversion coefficients and air kerma rates at the point of test) have been precisely determined through a series of measurements using the NaI(Tl) spectrometer and an ionisation chamber coupled with an appropriate build-up material. The measurements obtained comply with values recommended by the International Organization for Standardization for an 'R-F field'. The neutron contamination component for the field has also been measured by means of a conventional neutron dose equivalent meter (the so-called neutron rem-counter) and determined to be ∼0.5 % of the total dose equivalent. PMID:26012483

  8. Quality standards for ventilation devices and air conditioners; Qualitaetsstandards fuer Lueftungs- und Klimageraete

    Energy Technology Data Exchange (ETDEWEB)

    Backes, C. [DSD-Lufttechnik, St. Ingbert (Germany); Baumeister, R.L. [Robatherm, Burgau (Germany); Boehm, P. [TUEV Bayern-Sachsen, Muenchen (Germany); Lorenz, W. [Fachgemeinschaft Allgemeine Lufttechnik im VDMA, Frankfurt am Main (Germany)

    1995-07-01

    In Germany the requirements and testing of ventilation devices/space HVAC systems have not been standardised yet. In this work a report is given on the European standardisation activities and on the activities of the private industry with respect to quality assessment, both of which are setting new standards. This will have major effects on the market for these devices. (orig.) [Deutsch] Anforderungen und Pruefungen von raumlufttechnischen Geraeten sind in Deutschland bisher nicht standardisiert. Die europaeische Normung und privatwirtschaftliche Aktivitaeten zur Guetesicherung, ueber die in diesem Beitrag berichtet wird, setzen neue Massstaebe. Dies wird grundlegende Auswirkungen auf den Geraetemarkt haben. (orig.)

  9. Tissue kerma vs distance relationships for initial nuclear radiation from the atomic devices detonated over Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Initial nuclear radiation is comprised of prompt neutrons and prompt primary gammas from an exploding nuclear device, prompt secondary gammas produced by neutron interactions in the environment, and delayed neutrons and delayed fission-product gammas from the fireball formed after the nuclear device explodes. These various components must all be considered in establishing tissue kerma vs distance relationships which describe the decrease of initial nuclear radiation with distance in Hiroshima and in Nagasaki. The tissue kerma at ground evel from delayed fission-product gammas and delayed neutrons was investigated using the NUIDEA code developed by Science Applications, Inc. This code incorporates very detailed models which can take into account such features as the rise of the fireball, the rapid radioactive decay of fission products in it, and the perturbation of the atmosphere by the explosion. Tissue kerma vs distance relationships obtained by summing results of these current state-of-the-art calculations will be discussed. Our results clearly show that the prompt secondary gammas and delayed fission-product gammas are the dominant components of total tissue kerma from initial nuclear radiation in the cases of the atomic (or pure-fission) devices detonated over Hiroshima and Nagasaki

  10. National emission standards for hazardous air pollutants application for approval to stabilize the 105N Basin

    International Nuclear Information System (INIS)

    The 105N Basin (basin) Stabilization will place the basin in a radiologically and environmentally safe condition so that it can be decommissioned at a later date. The basin stabilization objectives are to inspect for Special Nuclear Material (SNM) (i.e., fuel assemblies and fuel pieces), remove the water from the basin and associated pits, and stabilize the basin surface. The stabilization will involve removal of basin hardware, removal of basin sediments, draining of basin water, and cleaning and stabilizing basin surfaces-to prevent resuspension of radioactive emissions to the air. These activities will be conducted in accordance with all applicable regulations. The basin is in the 105N Building, which is located in the 100N Area. The 100N Area is located in the Northern portion of the Hanford Site approximately 35 miles northwest of the city of Richland, Washington. The basin is a reinforced unlined concrete structure 150 feet long, 50 feet wide, and 24 feet deep. The basin is segregated into seven areas sharing a common pool of water; the Discharge/Viewing (''D'') Pit, the fuel segregation pit (including a water tunnel that connects the ''D'' pit and segregation pit), two storage basins designated as North Basin and South Basin, two cask load-out pits, and a fuel examination area. The North Basin floor is entirely covered and the South Basin is partly covered by a modular array of cubicles formed by boron concrete posts and boron concrete panels

  11. Hanford Site radionuclide national emission standards for hazardous air pollutants unregistered stack (power exhaust) source assessment

    International Nuclear Information System (INIS)

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission measurement requirements in 40 Code of Federal Regulations (CFR) 61, Subpart H, and to continuously measure radionuclide emissions in accordance with 40 CFR 61.93. This evaluation provides an assessment of the 39 unregistered stacks, under Westinghouse Hanford Company's management, and their potential radionuclide emissions, i.e., emissions with no control devices in place. The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified three stacks, 107-N, 296-P-26 and 296-P-28, as having potential emissions that would cause an effective dose equivalent greater than 0.1 mrem/yr. These stacks, as noted by 40 CFR 61.93, would require continuous monitoring

  12. 1996 Idaho National Engineering and Environmental Laboratory (INEEL) National Emissions Standards for Hazardous Air Pollutants (NESHAPs) -- Radionuclides. Annual report

    International Nuclear Information System (INIS)

    Under Section 61.94 of Title 40, Code of Federal Regulations (CFR), Part 61, Subpart H, ''National Emission Standards for Emissions of Radionuclides Other Than Radon From Department of Energy Facilities,'' each Department of Energy (DOE) facility must submit an annual report documenting compliance. This report addresses the Section 61.94 reporting requirements for operations at the Idaho National Engineering and Environmental Laboratory (INEEL) for calendar year (CY) 1996. The Idaho Operations Office of the DOE is the primary contact concerning compliance with the National Emission Standards for Hazardous Air Pollutants (NESHAPs) at the INEEL. For calendar year 1996, airborne radionuclide emissions from the INEEL operations were calculated to result in a maximum individual dose to a member of the public of 3.14E-02 mrem (3.14E-07 Sievert). This effective dose equivalent (EDE) is well below the 40 CFR 61, Subpart H, regulatory standard of 10 mrem per year (1.0E-04 Sievert per year)

  13. Effective atomic number, electron density and kerma of gamma radiation for oxides of lanthanides

    Indian Academy of Sciences (India)

    R S Niranjan; B Rudraswamy; N Dhananjaya

    2012-03-01

    An attempt has been made to estimate the effective atomic number, electron density (0.001 to 105 MeV) and kerma (0.001 to 20 MeV) of gamma radiation for a wide range of oxides of lanthanides using mass attenuation coefficient from WinXCom and mass energy absorption coefficient from Hubbell and Seltzer. The values of these parameters have been found to change with energy for different oxides of lanthanides. The lanthanide oxides find remarkable applications in the field of medicine, biology, nuclear engineering and space technology. Nano-oxides of lanthanide find applications in display and lighting industry.

  14. National Emission Standards for Hazardous Air Pollutants Calendar Year 2001; TOPICAL

    International Nuclear Information System (INIS)

    The Nevada Test Site (NTS) is operated by the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Operations Office (NNSA/NV) as the site for nuclear weapons testing, now limited to readiness activities, experiments in support of the national Stockpile Stewardship Program, and the activities listed below. Located in Nye County, Nevada, the site's southeast corner is about 88 km (55 mi) northwest of the major population center, Las Vegas, Nevada. The NTS covers about 3,561 km2 (1,375 mi2), an area larger than Rhode Island. Its size is 46 to 56 km (28 to 35 mi) east to west and from 64 to 88 km (40 to 55 mi) north to south. The NTS is surrounded, except on the south side, by public exclusion areas (Nellis Air Force Range[NAFR]) that provide another 24 to 104 km (15 to 65 mi) between the NTS and public lands (Figure 1.0). The NTS is characterized by desert valley and Great Basin mountain topography, with a climate, flora, and fauna typical of the southwest deserts. Population density within 150 km (93 mi) of the NTS is only about 0.2 persons per square kilometer, excluding the Las Vegas area. Restricted access, low population density in the surrounding area, and extended wind transport times are advantageous factors for the activities conducted at the NTS. Surface waters are scarce on the NTS, and slow-moving groundwater is present hundreds to thousands of feet below the land surface. The sources of radionuclides include current and previous activities conducted on the NTS (Figure 2.0). The NTS was the primary location for testing of nuclear explosives in the Continental U.S. between 1951 and 1992. Historical testing above or at ground surface has included (1) atmospheric testing in the 1950s and early 1960s, (2) earth-cratering experiments, and (3) open-air nuclear reactor and rocket engine testing. Since the mid-1950s, testing of nuclear explosive devices has occurred underground in drilled vertical holes or in mined tunnels (DOE 1996a

  15. Determination of the air attenuation and electronic loss for the free air concentric cylinders ionization chamber; Determinacao da atenuacao do ar e perda eletronica para a camara de ionizacao de ar livre de cilindros concentricos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Hebert Pinto Silveira de

    2010-07-01

    Along the latest years, the LNMRI has been proceeding a continuous research work with a concentric cylinders type free air ionizing chamber (VICTOREEN, model 481), aiming to establish it as a new national standard, and, as a consequence, replace the worldwide accepted secondary standard, calibrated by PTB. Taking into account that the absolute determination of kerma in air with a free air ionizing chamber implies the acquirement of a number of correction factors. The main objective of the present work comprises the determination of the two factors, specifically, electronic loss (k{sub e}) and air attenuation (k{sub a}). The correction factors were obtained through mammography qualities reference spectrum, using Monte Carlo simulation method. The Penelope code was used in the simulation procedures. Simulations took place in two stages, the acquirement of specters related to the qualities of interest (mammography) with the x ray tube (Pantak, model HF160 e Panalytical, model XRF window), and the free-air ionization chamber. The data were compared to those related to the BIPM chamber, to electronic loss were not detected. The comparison between air attenuation factors was obtained data bellow 0.13%. (author)

  16. 1997 Idaho National Engineering and Environmental Laboratory (INEEL) National Emission Standard for Hazardous Air Pollutants - Radionuclides. Annual report

    International Nuclear Information System (INIS)

    Under Section 61.94 of Title 40, Code of Federal Regulations (CFR), Part 61, Subpart H, National Emission Standards for Emissions of Radionuclides Other Than Radon From Department of Energy Facilities, each Department of Energy (DOE) facility must submit an annual report documenting compliance. This report addresses the Section 61.94 reporting requirements for operations at the Idaho National Engineering and Environmental Laboratory (INEEL) for calendar year (CY) 1997. Section 1 of this report provides an overview of the INEEL facilities and a brief description of the radioactive materials and processes at the facilities. Section 2 identifies radioactive air effluent release points and diffuse sources at the INEEL and actual releases during 1997. Section 2 also describes the effluent control systems for each potential release point. Section 3 provides the methodology and EDE calculations for 1997 INEEL radioactive emissions

  17. Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Blough, E.; Russell, W.; Leach, J.W.

    1990-08-01

    Computer models have been developed for evaluating conceptual designs of integrated coal gasification combined cycle power plants. An overall system model was developed for performing thermodynamic cycle analyses, and detailed models were developed for predicting performance characteristics of fixed bed coal gasifiers and hot gas clean up subsystem components. The overall system model performs mass and energy balances and does chemical equilibrium analyses to determine the effects of changes in operating conditions, or to evaluate proposed design changes. An existing plug flow model for fixed bed gasifiers known as the Wen II model was revised and updated. Also, a spread sheet model of zinc ferrite sulfur sorbent regeneration subsystem was developed. Parametric analyses were performed to determine how performance depends on variables in the system design. The work was done to support CRS Sirrine Incorporated in their study of standardized air blown coal gasifier gas turbine concepts.

  18. The Belgian laboratory for standard dosimetry calibrations used in radiotherapy

    International Nuclear Information System (INIS)

    Starting from the end of the year 2008, the RDC (Radiation Protection dosimetry and Calibrations) expertise group of SCK CEN took over the calibration and research activities at the Laboratory for Standard Dosimetry Ghent. The laboratory runs under a collaboration between SCK CEN and the University of Ghent, with the support of Federal Agency for Nuclear Control (FANC). The calibrations in Ghent were stopped at the beginning of 2008 and then restarted at the end of 2008. A new 60Co source was installed at Ghent, a Theratron 780 unit. All the calibration setups installed in the past to the old 60Co source had to move to the new source and measurement history had to be acquired. The calibration of cylindrical and plane-parallel ionization chambers in terms of absorbed dose to water was defined as the first priority, since there was an urgent need from the Belgian hospitals. These calibrations are presently done in Ghent as secondary standard calibrations, traceable to the water calorimeter of VSL, Delft, The Netherlands and following the recommendations from TRS-398 protocol. The second priority was restarting the calibrations of cylindrical ionization chambers in terms of air kerma. A cylindrical graphite ionization chamber of type CC01 is used for the absolute measurement of air kerma. Both setups are fully operational. Special efforts were done to implement the SCK CEN quality assurance (QA) system regarding ISO 17025 accreditation. The activity at the laboratory in Ghent was integrated as part of the Laboratory for Nuclear Calibrations (LNK-from the Dutch translation) of the SCK-CEN. Most of the activities of the LNK are already accredited by Belgian Accreditation Body (BELAC) with respect to the ISO-17025 standards. The quality assurance procedures were prepared and are routinely followed for the two new setups mentioned above: calibrations in terms of absorbed dose to water and air kerma in 60Co beam. During the preparation of the quality assurance procedures

  19. Design and preliminary test of a free-air ionization chamber for low-energy X-ray

    Institute of Scientific and Technical Information of China (English)

    吴金杰; 杨元第; 王培玮; 陈靖; 柳加成

    2011-01-01

    A free-air ionization chamber in low-energy X-ray has been designed and manufactured at the National Institute of Metrology (NIM, China) according to the defination of air-kerma. The results of a preliminary test show that the leakage current of ionizatio

  20. The effects of energy paths and emission controls and standards on future trends in China's emissions of primary air pollutants

    Science.gov (United States)

    Zhao, Y.; Zhang, J.; Nielsen, C. P.

    2014-09-01

    To examine the efficacy of China's actions to control atmospheric pollution, three levels of growth of energy consumption and three levels of implementation of emission controls are estimated, generating a total of nine combined activity-emission control scenarios that are then used to estimate trends of national emissions of primary air pollutants through 2030. The emission control strategies are expected to have more effects than the energy paths on the future emission trends for all the concerned pollutants. As recently promulgated national action plans of air pollution prevention and control (NAPAPPC) are implemented, China's anthropogenic pollutant emissions should decline. For example, the emissions of SO2, NOx, total suspended particles (TSP), PM10, and PM2.5 are estimated to decline 7, 20, 41, 34, and 31% from 2010 to 2030, respectively, in the "best guess" scenario that includes national commitment of energy saving policy and implementation of NAPAPPC. Should the issued/proposed emission standards be fully achieved, a less likely scenario, annual emissions would be further reduced, ranging from 17 (for primary PM2.5) to 29% (for NOx) declines in 2015, and the analogue numbers would be 12 and 24% in 2030. The uncertainties of emission projections result mainly from the uncertain operational conditions of swiftly proliferating air pollutant control devices and lack of detailed information about emission control plans by region. The predicted emission trends by sector and chemical species raise concerns about current pollution control strategies: the potential for emissions abatement in key sectors may be declining due to the near saturation of emission control devices use; risks of ecosystem acidification could rise because emissions of alkaline base cations may be declining faster than those of SO2; and radiative forcing could rise because emissions of positive-forcing carbonaceous aerosols may decline more slowly than those of SO2 emissions and thereby

  1. The effects of energy paths and emission controls and standards on future trends in China's emissions of primary air pollutants

    Directory of Open Access Journals (Sweden)

    Y. Zhao

    2014-03-01

    Full Text Available To examine the efficacy of China's actions to control atmospheric pollution, three levels of growth of energy consumption and three levels of implementation of emission controls are estimated, generating a total of nine combined activity-emission control scenarios that are then used to estimate trends of national emissions of primary air pollutants through 2030. The emission control strategies are expected to have more effects than the energy paths on the future emission trends for all the concerned pollutants. As recently promulgated national action plans of air pollution prevention and control (NAPAPPC are implemented, China's anthropogenic pollutant emissions should decline. For example, the emissions of SO2, NOx, total primary particulate matter (PM, PM10, and PM2.5 are estimated to decline 7%, 20%, 41%, 34%, and 31% from 2010 to 2030, respectively, in the "best guess" scenario that includes national commitment of energy saving policy and partial implementation of NAPAPPC. Should the issued/proposed emission standards be fully achieved, a less likely scenario, annual emissions would be further reduced, ranging from 17% (for primary PM2.5 to 29% (for NOx declines in 2015, and the analogue numbers would be 12% and 24% in 2030. The uncertainties of emission projections result mainly from the uncertain operational conditions of swiftly proliferating air pollutant control devices and lack of detailed information about emission control plans by region. The predicted emission trends by sector and chemical species raise concerns about current pollution control strategies: the potential for emissions abatement in key sectors may be declining due to the near saturation of emission control devices use; risks of ecosystem acidification could rise because emissions of alkaline base cations may be declining faster than those of SO2; and radiative forcing could rise because emissions of positive-forcing carbonaceous aerosols may decline more slowly than

  2. The Recent Development of the Test Standards for Ventilation air filters and Cabin Air Filters%通风和座舱空气过滤器试验标准的最新进展

    Institute of Scientific and Technical Information of China (English)

    丰兰

    2011-01-01

    The test standards and methods for two different air filters of ventilation air filters and cabin air filters were introduced,especially the difference of the test standards and methods between the ventilation air filters and cabin air filters.And the international present situation and the problem existed internal were also pointed,finally the development of cabin air filters were analyzed.%主要介绍了通风用空气过滤器和座舱式空气过滤器两个不同类型的空气过滤器的试验方法和标准,重点介绍了各试验方法和标准的区别,阐述分析了目前国际的现状和国内普遍存在的问题,最后介绍了目前座舱式空气过滤器的发展,为进一步研究提供参考。

  3. Dependence with air density of the response of the PTW SourceCheck ionization chamber for low energy brachytherapy sources

    International Nuclear Information System (INIS)

    Purpose: Air-communicating well ionization chambers are commonly used to assess air kerma strength of sources used in brachytherapy. The signal produced is supposed to be proportional to the air density within the chamber and, therefore, a density-independent air kerma strength is obtained when the measurement is corrected to standard atmospheric conditions using the usual temperature and pressure correction factor. Nevertheless, when assessing low energy sources, the ionization chambers may not fulfill that condition and a residual density dependence still remains after correction. In this work, the authors examined the behavior of the PTW 34051 SourceCheck ionization chamber when measuring the air kerma strength of 125I seeds.Methods: Four different SourceCheck chambers were analyzed. With each one of them, two series of measurements of the air kerma strength for 125I selectSeedTM brachytherapy sources were performed inside a pressure chamber and varying the pressure in a range from 747 to 1040 hPa (560 to 780 mm Hg). The temperature and relative humidity were kept basically constant. An analogous experiment was performed by taking measurements at different altitudes above sea level.Results: Contrary to other well-known ionization chambers, like the HDR1000 PLUS, in which the temperature-pressure correction factor overcorrects the measurements, in the SourceCheck ionization chamber they are undercorrected. At a typical atmospheric situation of 933 hPa (700 mm Hg) and 20 °C, this undercorrection turns out to be 1.5%. Corrected measurements show a residual linear dependence on the density and, as a consequence, an additional density dependent correction must be applied. The slope of this residual linear density dependence is different for each SourceCheck chamber investigated. The results obtained by taking measurements at different altitudes are compatible with those obtained with the pressure chamber.Conclusions: Variations of the altitude and changes in the

  4. Dependence with air density of the response of the PTW SourceCheck ionization chamber for low energy brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Tornero-López, Ana M.; Guirado, Damián; Ruiz-Arrebola, Samuel [Servicio de Radiofísica y Protección Radiológica, Hospital Universitario San Cecilio, E-18012 Granada (Spain); Perez-Calatayud, Jose [Servicio de Radioterapia, Unidad de Radiofísica, Hospital Universitario y Politécnico La Fe, E-46026 Valencia (Spain); Simancas, Fernando; Lallena, Antonio M. [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain); Gazdic-Santic, Maja [Department of Medical Physics and Radiation Safety, Clinical Centre of Sarajevo University, 71000 Sarajevo (Bosnia and Herzegovina)

    2013-12-15

    Purpose: Air-communicating well ionization chambers are commonly used to assess air kerma strength of sources used in brachytherapy. The signal produced is supposed to be proportional to the air density within the chamber and, therefore, a density-independent air kerma strength is obtained when the measurement is corrected to standard atmospheric conditions using the usual temperature and pressure correction factor. Nevertheless, when assessing low energy sources, the ionization chambers may not fulfill that condition and a residual density dependence still remains after correction. In this work, the authors examined the behavior of the PTW 34051 SourceCheck ionization chamber when measuring the air kerma strength of {sup 125}I seeds.Methods: Four different SourceCheck chambers were analyzed. With each one of them, two series of measurements of the air kerma strength for {sup 125}I selectSeed{sup TM} brachytherapy sources were performed inside a pressure chamber and varying the pressure in a range from 747 to 1040 hPa (560 to 780 mm Hg). The temperature and relative humidity were kept basically constant. An analogous experiment was performed by taking measurements at different altitudes above sea level.Results: Contrary to other well-known ionization chambers, like the HDR1000 PLUS, in which the temperature-pressure correction factor overcorrects the measurements, in the SourceCheck ionization chamber they are undercorrected. At a typical atmospheric situation of 933 hPa (700 mm Hg) and 20 °C, this undercorrection turns out to be 1.5%. Corrected measurements show a residual linear dependence on the density and, as a consequence, an additional density dependent correction must be applied. The slope of this residual linear density dependence is different for each SourceCheck chamber investigated. The results obtained by taking measurements at different altitudes are compatible with those obtained with the pressure chamber.Conclusions: Variations of the altitude and

  5. Development of a water calorimetry-based standard for absorbed dose to water in HDR 192Ir brachytherapy

    International Nuclear Information System (INIS)

    Purpose: The aim of this article is to develop and evaluate a primary standard for HDR 192Ir brachytherapy based on 4 deg. C stagnant water calorimetry. Methods: The absolute absorbed dose to water was directly measured for several different Nucletron microSelectron 192Ir sources of air kerma strength ranging between 21 000 and 38 000 U and for source-to-detector separations ranging between 25 and 70 mm. The COMSOL MULTIPHYSICS software was used to accurately calculate the heat transport in a detailed model geometry. Through a coupling of the ''conduction and convection'' module with the ''Navier-Stokes incompressible fluid'' module in the software, both the conductive and convective effects were modeled. Results: A detailed uncertainty analysis resulted in an overall uncertainty in the absorbed dose of 1.90%(1σ). However, this includes a 1.5% uncertainty associated with a nonlinear predrift correction which can be substantially reduced if sufficient time is provided for the system to come to a new equilibrium in between successive calorimetric runs, an opportunity not available to the authors in their clinical setting due to time constraints on the machine. An average normalized dose rate of 361±7 μGy/(h U) at a source-to-detector separation of 55 mm was measured for the microSelectron 192Ir source based on water calorimetry. The measured absorbed dose per air kerma strength agreed to better than 0.8%(1σ) with independent ionization chamber and EBT-1 Gafchromic film reference dosimetry as well as with the currently accepted AAPM TG-43 protocol measurements. Conclusions: This work paves the way toward a primary absorbed dose to water standard in 192Ir brachytherapy.

  6. 40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Science.gov (United States)

    2010-07-01

    ... waiver of the ozone monitoring requirement would be handled under provisions of 40 CFR, part 58. Some... year unless the appropriate Regional Administrator has granted a waiver under the provisions of 40 CFR... and Secondary National Ambient Air Quality Standards for Ozone H Appendix H to Part 50 Protection...

  7. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Interpretation of the 8-Hour Primary... AIR QUALITY STANDARDS Pt. 50, App. I Appendix I to Part 50—Interpretation of the 8-Hour Primary and... handling conventions and computations necessary for determining whether the national 8-hour primary...

  8. Establishment of standard x-ray qualities to be used in diagnostic level at SSDLs

    International Nuclear Information System (INIS)

    The objective of the present work is to modify x-ray machine (used by the secondary standard dosimetry laboratory in Sudan) to produce x-ray qualities suitable for the calibration at diagnostic level. It based on experimental evaluations. The importance of this study appears in development of protocols to calibrate the instruments used in diagnostic radiology in by good response of the instruments and low cost. In particular, the half value layer (HVL) values for the following qualities 40, 60, 80, 100, 120 and 150 were determined using various attenuation layers. Ionization chamber was used to determine the free air kerma rate at a distance of 100 cm from the x-ray generator. The obtained HVL values were compared with standard values of diagnostic levels. It was observed that the HVL of the present x-ray machine in most qualities are smaller than the standard ones. An approved method (described in the standard IEC 61267) was applied to determine the amount of additional filtration required to meet the standard values. The results show that the available cupper layers were not suitable for this purpose as most of the x-ray was absorbed in the material. Aluminum layers, on the other hand , show good performances to reduce the beams to the desired levels. The amount of additional filtration (from aluminum layers) needed in order to establish standard x-ray qualities to be used in diagnostic level were determined.(Author)

  9. Establishment of medium-hard x-ray reference fields for performance tests of radiation measuring instruments based on national standard

    International Nuclear Information System (INIS)

    In the Japanese Industrial Standard, JIS Z 4511 sets the condition of X-ray reference fields to be used for the performance test of radiation measuring instruments for radiation protection. We renewed a X-ray tube of the medium-hard X-ray irradiation device that was damaged in the Facility of Radiation Standards in Nuclear Science Research Institute. Therefore, we established four series of medium-hard X-ray reference fields with quality index of 0.6, 0.7, 0.8 and 0.9 based on JIS Z 4511. In this article, quality of the X-ray fields, X-ray spectra, conversion coefficients to the dose equivalents from Air-kerma were evaluated in the medium-hard X-ray fields produced with X-ray tube voltage ranging from 20 kV to 300 kV, and set about 52 qualities of medium-hard X-ray reference fields based on JIS Z 4511. These X-ray reference fields were well adapted to a setting condition of JIS and precision of conversion factors to various dose equivalents from Air-kerma was good. We also confirmed the soundness of the spectrum of each X-ray quality. As a result, medium-hard X-ray reference fields were established that can provide the dose equivalent standard with good precision and wide range of test energy points and dose rates, for the performance tests such as the energy characteristic and the direction characteristic for various radiation measuring instruments. We clarified these detailed data. (author)

  10. Estándares para el Sistema de Bibliotecas de la Universidad de Buenos Aires Standards for the Universidad de Buenos Aires Libraries System

    OpenAIRE

    Elsa Elena Elizalde

    2009-01-01

    La Coordinación General del Sistema de Bibliotecas y de Información -SISBI- de la Universidad de Buenos Aires propuso la conformación de un Grupo de Trabajo para el estudio y la definición de los requerimientos para un adecuado nivel de prestación de los servicios de todas sus bibliotecas. Estos estándares externos completarán y actualizarán los «Lineamientos para una Política Bibliotecaria de la Universidad de Buenos Aires (Resolución CS Nº 222/94)». El objetivo del conjunto de criterios que...

  11. The A&WMA 2007 Critical Review. Will the circle be unbroken: a history of the U.S. national ambient air quality standards

    Energy Technology Data Exchange (ETDEWEB)

    John Bachmann [Vision Air Consulting, Chapel Hill, NC (United States)

    2007-06-15

    In celebration of the 100th anniversary of the Air & Waste Management Association, this review examines the history of air quality management (AQM) in the United States over the last century, with an emphasis on the programs established by the 1970 Clean Air Act (CAA) Amendments. The current CAA system is a hybrid of several distinct air pollution control philosophies. The paper looks at several periods in the history of the U.S. program, including: (1) 1900-1970, spanning the early smoke abatement and smog control programs, the first federal involvement, and the development of a hybrid AQM approach in the 1970 CAA; (2) 1971-1976, when the first National Ambient Air Quality Standards (NAAQS) were set and implemented; (3) 1977-1993, a period of the first revisions to the standards, new CAA Amendments, delays in implementation and decision-making, and key science/policy/legislative developments that would alter both the focus and scale of air pollution programs and how they are implemented; and (4) 1993-2006, the second and third wave of NAAQS revisions and their implementation in the context of the 1990 CAA. This discussion examines where NAAQS have helped drive implementation programs and how improvements in both effects and air quality/control sciences influenced policy and legislation to enhance the effectiveness of the system over time. The review concludes with a look toward the future of AQM, emphasizing challenges and ways to meet them. Supplemental tables 1 to 7, available to subscribers at www.awma.org/journals/pdfs/2007/6/10.3155-1047-3289.57.6.652_supplmat erial.pdf present detailed chronology and commentary on the development of criteria and establishing, reviewing, and revising the NAAQS for each of the seven pollutants that were listed and regulated under Sections 108 and 109 between 1971 and 2006. 250 refs., 11 figs., 6 tabs.

  12. Indoor Air Quality In Maine Schools: Report of the Task Force To Examine the Establishment and Implementation of State Standards for Indoor Air Quality in Maine Schools.

    Science.gov (United States)

    Malcolm, Judith

    Asserting that in Maine and across the nation, school buildings are becoming increasingly plagued with indoor air quality (IAQ) problems which contribute to a variety of illnesses in children and adults, this report from a Maine state legislative task force identifies appropriate policies and identifies actions necessary for the prevention and…

  13. The Fricke dosimeter as an absorbed dose to water primary standard for Ir-192 brachytherapy

    Science.gov (United States)

    El Gamal, Islam; Cojocaru, Claudiu; Mainegra-Hing, Ernesto; McEwen, Malcolm

    2015-06-01

    The aim of this project was to develop an absorbed dose to water primary standard for Ir-192 brachytherapy based on the Fricke dosimeter. To achieve this within the framework of the existing TG-43 protocol, a determination of the absorbed dose to water at the reference position, D(r0,θ0), was undertaken. Prior to this investigation, the radiation chemical yield of the ferric ions (G-value) at the Ir-192 equivalent photon energy (0.380 MeV) was established by interpolating between G-values obtained for Co-60 and 250 kV x-rays. An irradiation geometry was developed with a cylindrical holder to contain the Fricke solution and allow irradiations in a water phantom to be conducted using a standard Nucletron microSelectron V2 HDR Ir-192 afterloader. Once the geometry and holder were optimized, the dose obtained with the Fricke system was compared to the standard method used in North America, based on air-kerma strength. Initial investigations focused on reproducible positioning of the ring-shaped holder for the Fricke solution with respect to the Ir-192 source and obtaining an acceptable type A uncertainty in the optical density measurements required to yield the absorbed dose. Source positioning was found to be reproducible to better than 0.3 mm, and a careful cleaning and control procedure reduced the variation in optical density reading due to contamination of the Fricke solution by the PMMA holder. It was found that fewer than 10 irradiations were required to yield a type A standard uncertainty of less than 0.5%. Correction factors to take account of the non-water components of the geometry and the volume averaging effect of the Fricke solution volume were obtained from Monte Carlo calculations. A sensitivity analysis showed that the dependence on the input data used (e.g. interaction cross-sections) was small with a type B uncertainty for these corrections estimated to be 0.2%. The combined standard uncertainty in the determination of absorbed dose to water

  14. The Fricke dosimeter as an absorbed dose to water primary standard for Ir-192 brachytherapy

    International Nuclear Information System (INIS)

    The aim of this project was to develop an absorbed dose to water primary standard for Ir-192 brachytherapy based on the Fricke dosimeter. To achieve this within the framework of the existing TG-43 protocol, a determination of the absorbed dose to water at the reference position, D(r0,θ0), was undertaken. Prior to this investigation, the radiation chemical yield of the ferric ions (G-value) at the Ir-192 equivalent photon energy (0.380 MeV) was established by interpolating between G-values obtained for Co-60 and 250 kV x-rays.An irradiation geometry was developed with a cylindrical holder to contain the Fricke solution and allow irradiations in a water phantom to be conducted using a standard Nucletron microSelectron V2 HDR Ir-192 afterloader. Once the geometry and holder were optimized, the dose obtained with the Fricke system was compared to the standard method used in North America, based on air-kerma strength.Initial investigations focused on reproducible positioning of the ring-shaped holder for the Fricke solution with respect to the Ir-192 source and obtaining an acceptable type A uncertainty in the optical density measurements required to yield the absorbed dose. Source positioning was found to be reproducible to better than 0.3 mm, and a careful cleaning and control procedure reduced the variation in optical density reading due to contamination of the Fricke solution by the PMMA holder. It was found that fewer than 10 irradiations were required to yield a type A standard uncertainty of less than 0.5%.Correction factors to take account of the non-water components of the geometry and the volume averaging effect of the Fricke solution volume were obtained from Monte Carlo calculations. A sensitivity analysis showed that the dependence on the input data used (e.g. interaction cross-sections) was small with a type B uncertainty for these corrections estimated to be 0.2%.The combined standard uncertainty in the determination of absorbed dose to water at

  15. 75 FR 10252 - Release of Draft Documents Related to the Review of the National Ambient Air Quality Standards...

    Science.gov (United States)

    2010-03-05

    ... Exposure Assessment to Support the Review of the Carbon Monoxide Primary National Ambient Air Quality... draft assessment document: Policy Assessment for the Review of the Carbon Monoxide National Ambient Air... Risk and Exposure Assessment to Support the Review of the Carbon Monoxide Primary National Ambient......

  16. 78 FR 20881 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards...

    Science.gov (United States)

    2013-04-08

    ... AGENCY 40 CFR Part 80 RIN 2060-AQ86 Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle... hearings to be held for the proposed rule ``Control of Air Pollution from Motor Vehicles: Tier 3 Motor... cars, light-duty trucks, medium- duty passenger vehicles, and some heavy-duty vehicles. This...

  17. Standard Air Pollution Classification Network: A Thesaurus of Terms (As Used in the APTIC Data Base). Second Edition.

    Science.gov (United States)

    Halpin, Peter

    This thesaurus presents the specialized terminology and air pollution indexing terms used for the storage of, and search for, information in the Air Pollution Technical Information Center (APTIC) data base file, and illustrates the rules formulated for their use. The meanings of the terms are implied rather than defined, being implicit in the…

  18. Quality control methodology and implementation of X-radiation standards beams, mammography level, following the standard IEC 61267

    International Nuclear Information System (INIS)

    In this work it was developed and applied a quality control program of the X radiation system (160 kV, constant potential, target of tungsten) of the Calibration Laboratory of IPEN(LCI) in the energy range relative to mammography beams (from 25 kV to 35 kV). The X radiation standards beams, level mammography, using molybdenum and aluminum as additional filtration, were established after the application of this quality control program following national and international recommendations. The reference ionization chamber has traceability to PTB and was regularly submitted to quality control tests for evaluation and analysis of its performance. The radiation qualities emerging from the X-radiation assembly (RQR-M), based on a phantom made up of an aluminum added filter (RQA-M), narrow beam condition (RQN-M) and broad beam condition (RQB-M), following the recommendations of the international standard IEC 61267 (2005) and the IAEA code of practice, TRS 457 (2007) were established. For the implantation of RQN-M and RQB-M radiation qualities, two mammography phantoms were developed. The half-value layers found are those presented by the German primary laboratory PTB, and varied from 0.35 to 1.21 mm Al. The air kerma rates were obtained for all the 15 implanted qualities. (author)

  19. 75 FR 70258 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-11-17

    ... to: Air and Radiation Docket and Information Center, Environmental Protection Agency, Mailcode: 2822T... an atmospheric chemistry perspective as well as from an environmental effects perspective, and... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL...

  20. Comparison between predicted duct effectiveness from proposed ASHRAE Standard 152P and measured field data for residential forced air cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Siegel, Jeffrey A.; McWilliams, Jennifer A.; Walker, Iain S.

    2002-04-01

    The proposed ASHRAE Standard 152P ''Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems'' (ASHRAE 2002) has recently completed its second public review. As part of the standard development process, this study compares the forced air distribution system ratings provided by the public review draft of Standard 152P to measured field results. 58 field tests were performed on cooling systems in 11 homes in the summers of 1998 and 1999. Seven of these houses had standard attics with insulation on the attic floor and a well-vented attic space. The other four houses had unvented attics where the insulation is placed directly under the roof deck and the attic space is not deliberately vented. Each house was tested under a range of summer weather conditions at each particular site, and in some cases the amount of duct leakage was intentionally varied. The comparison between 152P predicted efficiencies and the measured results includes evaluation of the effects of weather, duct location, thermal conditions, duct leakage, and system capacity. The results showed that the difference between measured delivery effectiveness and that calculated using proposed Standard 152P is about 5 percentage points if weather data, duct leakage and air handler flow are well known. However, the accuracy of the standard is strongly dependent on having good measurements of duct leakage and system airflow. Given that the uncertainty in the measured delivery effectiveness is typically also about 5 percentage points, the Standard 152P results are acceptably close to the measured data.

  1. First international comparison of primary absorbed dose to water standards in the medium-energy X-ray range

    Science.gov (United States)

    Büermann, Ludwig; Guerra, Antonio Stefano; Pimpinella, Maria; Pinto, Massimo; de Pooter, Jacco; de Prez, Leon; Jansen, Bartel; Denoziere, Marc; Rapp, Benjamin

    2016-01-01

    This report presents the results of the first international comparison of primary measurement standards of absorbed dose to water for the medium-energy X-ray range. Three of the participants (VSL, PTB, LNE-LNHB) used their existing water calorimeter based standards and one participant (ENEA) recently developed a new standard based on a water-graphite calorimeter. The participants calibrated three transfer chambers of the same type in terms of absorbed dose to water (NDw) and in addition in terms of air kerma (NK) using the CCRI radiation qualities in the range 100 kV to 250 kV. The additional NK values were intended to be used for a physical analysis of the ratios NDw/NK. All participants had previously participated in the BIPM.RI(I)-K3 key comparison of air kerma standards. Ratios of pairs of NMI's NK results of the current comparison were found to be consistent with the corresponding key comparison results within the expanded uncertainties of 0.6 % - 1 %. The NDw results were analysed in terms of the degrees of equivalence with the comparison reference values which were calculated for each beam quality as the weighted means of all results. The participant's results were consistent with the reference value within the expanded uncertainties. However, these expanded uncertainties varied significantly and ranged between about 1-1.8 % for the water calorimeter based standards and were estimated at 3.7 % for the water-graphite calorimeter. It was shown previously that the ratios NDw/NK for the type of ionization chamber used as transfer chamber in this comparison were very close (within less than 1 %) to the calculated values of (bar muen/ρ)w,ad, the mean values of the water-to-air ratio of the mass-energy-absorption coefficients at the depth d in water. Some of the participant's results deviated significantly from the expected behavior. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of

  2. 75 FR 1566 - Public Hearings for Reconsideration of the 2008 National Ambient Air Quality Standards for Ozone

    Science.gov (United States)

    2010-01-12

    ... the following Web site: http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_fr.html for the addresses.../standards/ozone/s_o3_cr_fr.html . FOR FURTHER INFORMATION CONTACT: If you would like to speak at the public... proposal at http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_fr.html prior to the hearings....

  3. Standard guide for use of thermocouples in creep and stress-rupture testing to 1800°F (1000°C) in air

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This guide covers the use of ANSI thermocouple Types K, N, R, and S for creep and stress-rupture testing at temperatures up to 1800°F (1000°C) in air at one atmosphere of pressure. It does not cover the use of sheathed thermocouples. 1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only. 1.3This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  4. 77 FR 23399 - National Emission Standards for Hazardous Air Pollutants From Coal- and Oil-Fired Electric...

    Science.gov (United States)

    2012-04-19

    ..., Subpart CCCC (New Source Performance Standards (NSPS) for Commercial and Industrial Solid Waste... Pollutants From Coal- and Oil-Fired Electric Utility Steam Generating Units and Standards of Performance for..., 2012 (77 FR 9304). DATES: Effective date: April 19, 2012. FOR FURTHER INFORMATION CONTACT: For...

  5. 40 CFR Appendix K to Part 50 - Interpretation of the National Ambient Air Quality Standards for Particulate Matter

    Science.gov (United States)

    2010-07-01

    ... particulate matter data to determine attainment of the 24-hour standards specified in 40 CFR 50.6. For the... Determinations 2.124-Hour Primary and Secondary Standards (a) Under 40 CFR 50.6(a) the 24-hour primary and....1, which is the lowest rate for nonattainment). 2.2Reserved 2.3Data Requirements (a) 40 CFR...

  6. 77 FR 36341 - Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

    Science.gov (United States)

    2012-06-18

    ...EPA is adopting several new aircraft engine emission standards for oxides of nitrogen (NOX), compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet engines with rated thrusts greater than 26.7 kilonewtons (kN). We also are adopting certain other requirements for gas turbine engines that are subject to exhaust emission standards as follows.......

  7. 76 FR 24975 - National Emission Standards for Hazardous Air Pollutants From Coal- and Oil-Fired Electric...

    Science.gov (United States)

    2011-05-03

    ... toxic air pollutants such as the acid gases hydrogen chloride (HCl) and hydrogen fluoride (HF). Adverse... developing fetus, and that about 1 percent were exposed to 3 to 4 times that level. 65 FR 79827. Moreover, in... associated with reducing exposure to MeHg, PM2.5, and ozone. c Based on an analysis of health effects due...

  8. Efficacy and safety of TachoSil® versus standard treatment of air leakage after pulmonary lobectomy

    DEFF Research Database (Denmark)

    Marta, Gabriel Mihai; Facciolo, Francesco; Ladegaard, Lars; Dienemann, Hendrik; Csekeo, Attila; Rea, Federico; Dango, Sebastian; Spaggiari, Lorenzo; Tetens, Vilhelm; Klepetko, Walter

    2010-01-01

    Alveolar air leakage remains a serious problem in lung surgery, being associated with increased postoperative morbidity, prolonged hospital stay and greater health-care costs. The aim of this study was to evaluate the sealing efficacy and safety of the surgical patch, TachoSil®, in lung surgery....

  9. 2007 Critical Review Discussion -- Will the circle be unbroken: a history of the U.S. national ambient air quality standards

    Energy Technology Data Exchange (ETDEWEB)

    Judith C. Chow; John G. Watson; Howard J. Feldman (and others) [Desert Research Institute, Reno, NV (United States)

    2007-10-15

    In the review, John D. Bachmann traces the regulatory history of U.S. air pollution from the beginning of the 20th century to the present. The review divides this progress into four segments: (1) 1900-1970, from smoke abatement to federal involvement and the establishment of air quality management (AQM) in the 1970 Clean Air Act (CAA); (2) 1971-1976, when the first National Ambient Air Quality Standards (NAAQS) were promulgated and implemented; (3) 1977-1993, which included the first NAAQS revisions, major CAA amendments, and the evolution of AQM; and (4) 1993-2006, the second and third waves of NAAQS revisions and their implementation in the context of the 1990 CAA amendments. A discussant's commentary does not necessarily reflect the position of his or her respective organization. This Critical Review Discussion was compiled from written submissions and presentation transcripts. The invited discussants are as follows: Mr. Howard J. Feldman, director of regulatory and scientific affairs for the American Petroleum Institute; Ms. Janice E. Nolen, assistant vice president of national policy and advocacy for the American Lung Association; Dr. Barry Wallerstein, executive officer at the South Coast Air Quality Management District; Dr. John G. Watson, research professor in the Division of Atmospheric Sciences at the Desert Research Institute; Dr. George M. Hidy of Envair/Aerochem; Dr. Paul J. Lioy, Department of Environmental and Occupational Medicine; Robert Wood Johnson Medical School, University of Medicine and Dentistry, New Jersey; Dr. Herbert McKee, environmental consultant; Mr. David Mobley of the Atmospheric Modeling Division of the EPA's Office of Research and Development; and Mr. Keith Baugues, P.E., of air services for KERAMIDA Environmental. 127 refs.

  10. A reevaluation of the National Emission Standards for Hazardous Air Pollutants (NESHAP - 40 CFR 61, Subpart H) program at Sandia National Laboratories, New Mexico

    International Nuclear Information System (INIS)

    The initial National Emission Standards for Hazardous Air Pollutants (NESHAP - 40 CFR 61, Subpart H) Program at Sandia National Laboratories, New Mexico (SNL/NM) required: (1) continuous air monitoring of sources if the calculated effective dose equivalent (EDE) to the maximum exposed individual (MEI) was > 0.1 mrem/yr; (2) the determination of emissions based on measurements or measured parameters if the EDE to the MEI was < 0.1 mrem/yr; and (3) the calculation of worst case releases when the expected air concentrations were below detection limits using standard monitoring equipment. This conservative interpretation of the regulation guided SNL/NM to model, track, and trend virtually all emission sources with the potential to include any radionuclides. The level of effort required to implement these activities was independent of the EDE contributing from individual sources. A recent programmatic review found the NESHAP program to be in excess of the legal requirements. A further review found that, in summation, 13 of 16 radionuclide sources had a negligible impact on the final calculated EDE to the MEI used to demonstrate compliance at 20 separate on-site receptor locations. A reevaluation was performed to meet the legal requirements of 40 CFR 61, Subpart H, and still be reasonable and appropriate under the existing circumstances

  11. Technical Requirements and Principles for the Standards Development of the Key Parts for Rotor Air-conditioning Compressors

    Institute of Scientific and Technical Information of China (English)

    Sun Min; Wen Yun; Fan Zhangzeng

    2011-01-01

    ntroductionSince 2000,air-conditioning sales continues to grow,and the development of air-conditioning market makes a booming market of compressor.At the present time,compressor production rising all the way,and the sales steps up the new steps constantly.Tendency chart is shown in figure 1.Rotor compressor with its simple structure,small volume,light weight,easy processed mechanical parts,reliable operation and other excellent characteristics occupied the dominant position in the market.Compared with reciprocating compressor on the same application situation,decreased in the size by 40%~50%,weight was reduced by 40%~50%.But there were also disadvantages,mainly large friction loss,friction power consumption was about 10%of compressor's total power input.

  12. The effects of energy paths and emission controls and standards on future trends in China's emissions of primary air pollutants

    OpenAIRE

    Zhao, Y.; Zhang, J.; C. P. Nielsen

    2014-01-01

    To examine the efficacy of China's actions to control atmospheric pollution, three levels of growth of energy consumption and three levels of implementation of emission controls are estimated, generating a total of nine combined activity-emission control scenarios that are then used to estimate trends of national emissions of primary air pollutants through 2030. The emission control strategies are expected to have more effects than the energy paths on the future emission tre...

  13. The effects of energy paths and emission controls and standards on future trends in China's emissions of primary air pollutants

    OpenAIRE

    Zhao, Y.; Zhang, J.; C. P. Nielsen

    2014-01-01

    To examine the efficacy of China's actions to control atmospheric pollution, three levels of growth of energy consumption and three levels of implementation of emission controls are estimated, generating a total of nine combined activity-emission control scenarios that are then used to estimate trends of national emissions of primary air pollutants through 2030. The emission control strategies are expected to have more effects than the energy paths on the fu...

  14. Quality control methodology and implementation of X-radiation standards beams, mammography level, following the standard IEC 61267

    Energy Technology Data Exchange (ETDEWEB)

    Correa, E.L.; Vivolo, V. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Avenida Professor Lineu Prestes 2242, Cidade Universitaria, Sao Paulo, SP (Brazil); Potiens, M.P.A., E-mail: mppalbu@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Avenida Professor Lineu Prestes 2242, Cidade Universitaria, Sao Paulo, SP (Brazil)

    2012-07-15

    This study presents the results of the establishment of a quality control program developed and applied for the X-ray system of the Calibration Laboratory of IPEN. The X-ray standard beams, mammography level, using molybdenum and aluminum as additional filtration were established after the application of this quality control and the spectrometry of these qualities was made. The reference ionization chamber has traceability to the PTB. The radiation qualities RQR-M, RQA-M, RQN-M and RQB-M, following the recommendations of the IEC 61267 and the IAEA TRS 457 were established. - Highlights: Black-Right-Pointing-Pointer Determination of the additional filtration for each mammography radiation quality. Black-Right-Pointing-Pointer Determination of the KQ values for the WAV and WMV radiation qualities. Black-Right-Pointing-Pointer Determination of the air-kerma rates for all radiation qualities. Black-Right-Pointing-Pointer The uncertainties have been calculated using the type A and type B uncertainties. Black-Right-Pointing-Pointer Establishment of the qualities that use a PMMA phantom (WAN, WAB, WMN and WMB).

  15. An absorbed dose to water standard for HDR 192Ir brachytherapy sources based on water calorimetry: Numerical and experimental proof-of-principle

    International Nuclear Information System (INIS)

    Water calorimetry is an established technique for absorbed dose to water measurements in external beams. In this paper, the feasibility of direct absorbed dose measurements for high dose rate (HDR) iridium-192 (192Ir) sources using water calorimetry is established. Feasibility is determined primarily by a balance between the need to obtain sufficient signal to perform a reproducible measurement, the effect of heat loss on the measured signal, and the positioning uncertainty affecting the source-detector distance. The heat conduction pattern generated in water by the Nucletron microSelectron-HDR 192Ir brachytherapy source was simulated using COMSOL MULTIPHYSICSTM software. Source heating due to radiation self-absorption was calculated using EGSnrcMP. A heat-loss correction kc was calculated as the ratio of the temperature rise under ideal conditions to temperature rise under realistic conditions. The calorimeter setup used a parallel-plate calorimeter vessel of 79 mm diameter and 1.12 mm thick front and rear glass windows located 24 mm apart. Absorbed dose was measured with two sources with nominal air kerma strengths of 38 000 and 21 000 U, at source-detector separations ranging from 24.7 to 27.6 mm and irradiation times of 36.0 to 80.0 s. The preliminary measured dose rate per unit air kerma strength of (0.502±0.007) μGy/(s U) compares well with the TG-43 derived 0.505 μGy/(s U). This work shows that combined dose uncertainties of significantly less than 5% can be achieved with only modest modifications of current water calorimetry techniques and instruments. This work forms the basis of a potential future absolute dose to water standard for HDR 192Ir brachytherapy

  16. An absorbed dose to water standard for HDR 192Ir brachytherapy sources based on water calorimetry: numerical and experimental proof-of-principle.

    Science.gov (United States)

    Sarfehnia, Arman; Stewart, Kristin; Seuntjens, Jan

    2007-12-01

    Water calorimetry is an established technique for absorbed dose to water measurements in external beams. In this paper, the feasibility of direct absorbed dose measurements for high dose rate (HDR) iridium-192 (192Ir) sources using water calorimetry is established. Feasibility is determined primarily by a balance between the need to obtain sufficient signal to perform a reproducible measurement, the effect of heat loss on the measured signal, and the positioning uncertainty affecting the source-detector distance. The heat conduction pattern generated in water by the Nucletron microSelectron-HDR 192Ir brachytherapy source was simulated using COMSOL MULTIPHYSICS software. Source heating due to radiation self-absorption was calculated using EGSnrcMP. A heat-loss correction k(c) was calculated as the ratio of the temperature rise under ideal conditions to temperature rise under realistic conditions. The calorimeter setup used a parallel-plate calorimeter vessel of 79 mm diameter and 1.12 mm thick front and rear glass windows located 24 mm apart. Absorbed dose was measured with two sources with nominal air kerma strengths of 38 000 and 21 000 U, at source-detector separations ranging from 24.7 to 27.6 mm and irradiation times of 36.0 to 80.0 s. The preliminary measured dose rate per unit air kerma strength of (0.502 +/- 0.007) microGy/(s U) compares well with the TG-43 derived 0.505 microGy/(s U). This work shows that combined dose uncertainties of significantly less than 5% can be achieved with only modest modifications of current water calorimetry techniques and instruments. This work forms the basis of a potential future absolute dose to water standard for HDR 192Ir brachytherapy. PMID:18196821

  17. Interlaboratory evaluation of a standardized inductively coupled plasma mass spectrometry method for the determination of trace beryllium in air filter samples.

    Science.gov (United States)

    Ashley, Kevin; Brisson, Michael J; Howe, Alan M; Bartley, David L

    2009-12-01

    A collaborative interlaboratory evaluation of a newly standardized inductively coupled plasma mass spectrometry (ICP-MS) method for determining trace beryllium in workplace air samples was carried out toward fulfillment of method validation requirements for ASTM International voluntary consensus standard test methods. The interlaboratory study (ILS) was performed in accordance with an applicable ASTM International standard practice, ASTM E691, which describes statistical procedures for investigating interlaboratory precision. Uncertainty was also estimated in accordance with ASTM D7440, which applies the International Organization for Standardization Guide to the Expression of Uncertainty in Measurement to air quality measurements. Performance evaluation materials (PEMs) used consisted of 37 mm diameter mixed cellulose ester filters that were spiked with beryllium at levels of 0.025 (low loading), 0.5 (medium loading), and 10 (high loading) microg Be/filter; these spiked filters were prepared by a contract laboratory. Participating laboratories were recruited from a pool of over 50 invitees; ultimately, 20 laboratories from Europe, North America, and Asia submitted ILS results. Triplicates of each PEM (blanks plus the three different loading levels) were conveyed to each volunteer laboratory, along with a copy of the draft standard test method that each participant was asked to follow; spiking levels were unknown to the participants. The laboratories were requested to prepare the PEMs by one of three sample preparation procedures (hotplate or microwave digestion or hotblock extraction) that were described in the draft standard. Participants were then asked to analyze aliquots of the prepared samples by ICP-MS and to report their data in units of mu g Be/filter sample. Interlaboratory precision estimates from participating laboratories, computed in accordance with ASTM E691, were 0.165, 0.108, and 0.151 (relative standard deviation) for the PEMs spiked at 0.025, 0

  18. The effect of the Standard Nomenclature for Air Pollution (SNAP) categories on ozone and PM2.5 concentrations over Europe

    Science.gov (United States)

    Tagaris, Efthimios; Sotiropoulou, Rafaella-Eleni P.; Gounaris, Nikos; Andronopoulos, Spyros; Vlachogiannis, Diamando

    2015-04-01

    The objective of this study is to estimate the contribution of different anthropogenic emission sources on ozone and PM2.5 concentrations over Europe since anthropogenic activities (and the related emissions) are the reason of air quality degradation. Gridded yearly averaged anthropogenic emissions for the year 2006 over Europe are provided by TNO at a 0.1×0.1 degree resolution. Emission sources have been classified into different activities according to the Standard Nomenclature for Air Pollution (SNAP). The available data include annual total emissions of CH4, CO, NH3, NMVOC, NOx, PM10, PM2.5, and SO2 for both area and point sources in ten (10) SNAP categories: power generation, residential-commercial and other combustion, industrial combustion, industrial processes, extraction distribution of fossil fuels, solvent use, road transport, other mobile sources, waste treatment and disposal, agriculture. Mobile sources and road transport are the major sources of NOx emissions followed by power generation units. Power generation is also the major source for SO2 emissions followed by mobile sources. Agricultural activities dominate NH3 emissions while combustion sources followed by mobile sources and road transport are the main sources for primary PM2.5. Emissions are processed by the Sparse Matrix Operator Kernel Emissions (SMOKE) v2.6 modeling system to convert their resolution to the resolution needed by the air quality model The Community Multiscale Air Quality (CMAQ) v4.7 Modeling System with the Carbon Bond mechanism (CB05) is used for the regional air quality modeling over Europe at 35km grid spacing. Results quantify the contribution of each SNAP category on ozone and PM2.5 concentrations, locally, across Europe.

  19. 1995 Idaho National Engineering Laboratory (INEL) National Emission Standards for Hazardous Air Pollutants (NESHAPs): Radionuclides. Annual report

    International Nuclear Information System (INIS)

    Under Section 61.94 of 40 CFR 61, Subpart H (National Emission Standards for Emissions of Radionuclides Other Than Radon From Department of Energy Facilities), each DOE facility must submit an annual report documenting compliance. This report addresses the Section 61.94 reporting requirements for operations at INEL for CY 1995. For that year, airborne radionuclide emissions from INEL operations were calculated to result in a maximum individual dose to a member of the public of 1.80E-02 mrem (1.80E-07 Sievert), well below the 40 CFR 61, Subpart H, regulatory standard of 10 mrem per year (1.0E-04 Sievert per year)

  20. Tank exhaust comparison with 40 CFR 61.93, Subpart H, and other referenced guidelines for Tank Farms National Emission Standards for Hazardous Air Pollutant (NESHAP) designated stacks

    International Nuclear Information System (INIS)

    The US Environmental Protection Agency (EPA) promulgated National Emission Standards other than Radon from US Department of Energy (DOE) Facilities (40 CFR 61, Subpart H) on December 15, 1989. The regulations specify procedures, equipment, and test methods that.are to be used to measure radionuclide emissions from exhaust stacks that are designated as National Emission Standards for Hazardous Air Pollutant (NESHAP) stacks. Designated NESHAP stacks are those that have the potential to cause any member of the public to receive an effective dose equivalent (EDE) greater than or equal to 0.1 mrem/year, assuming all emission controls were removed. Tank Farms currently has 33 exhaust stacks, 15 of which are designated NESHAP stacks. This document assesses the compliance status of the monitoring and sampling systems for the designated NESHAP stacks

  1. Tank exhaust comparison with 40 CFR 61.93, Subpart H, and other referenced guidelines for Tank Farms National Emission Standards for Hazardous Air Pollutant (NESHAP) designated stacks

    Energy Technology Data Exchange (ETDEWEB)

    Bachand, D.D.; Crummel, G.M.

    1994-07-01

    The US Environmental Protection Agency (EPA) promulgated National Emission Standards other than Radon from US Department of Energy (DOE) Facilities (40 CFR 61, Subpart H) on December 15, 1989. The regulations specify procedures, equipment, and test methods that.are to be used to measure radionuclide emissions from exhaust stacks that are designated as National Emission Standards for Hazardous Air Pollutant (NESHAP) stacks. Designated NESHAP stacks are those that have the potential to cause any member of the public to receive an effective dose equivalent (EDE) greater than or equal to 0.1 mrem/year, assuming all emission controls were removed. Tank Farms currently has 33 exhaust stacks, 15 of which are designated NESHAP stacks. This document assesses the compliance status of the monitoring and sampling systems for the designated NESHAP stacks.

  2. 76 FR 48073 - Public Hearing for Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and...

    Science.gov (United States)

    2011-08-08

    ... the notice of proposed rulemaking published in the Federal Register on August 1, 2011, (76 FR 46084....epa.gov/ttn/naaqs/standards/no2so2sec/cr_fr.html . FOR FURTHER INFORMATION CONTACT: If you would like... published in the Federal Register on August 1, 2011, (76 FR 46084) and is available on the following...

  3. Study of effective atomic numbers and electron densities, kerma of alcohols, phantom and human organs, and tissues substitutes

    Directory of Open Access Journals (Sweden)

    Singh Vishwanath P.

    2013-01-01

    Full Text Available Effective atomic numbers (ZPIeff and electron densities of eighteen alcohols such as wood alcohol, CH3OH; grain alcohol, C2H5OH; rubbing alcohol, C3H7OH; butanol, C4H9OH; amyl alcohol, C5H11OH; cetyl alcohol, C16H33OH; ethylene glycol, C2H4(OH2; glycerin, C3H5(OH3; PVA, C2H4O; erythritol, C4H6(OH4; xylitol, C5H7(OH5; sorbitol, C6H8(OH6; volemitol, C7H9(OH7; allyl alcohol, C3H5OH; geraniol, C10H17OH; propargyl alcohol, C3H3OH; inositol, C6H6(OH6, and menthol, C10H19OH have been calculated in the photon energy region of 1 keV-100 GeV. The estimated values have been compared with experimental values wherever possible. The comparison of ZPIeff of the alcohols with water phantom and PMMA phantom indicate that the ethylene glycol, glycerin, and PVA are substitute for PMMA phantom and PVA is substitute of water phantom. ZPIeff of alcohols have also been compared with human organs and tissues. Ethylene glycol, glycerin and PVA, allyl alcohol, and wood alcohols are found tissue substitutes for most of human organs. Kerma which is the product of the energy fluence and mass energy-absorption coefficient, have been calculated in the energy region from 1 keV to 20 MeV for the alcohols. The results show the kerma is more or less independent of energy above 100 keV.

  4. Biomonitoring of trace-element air pollution in a gold mining area in Ghana using the generalized k0-standardization NAA method

    International Nuclear Information System (INIS)

    Full text: Mining activities contribute immensely to trace element atmospheric pollution. In Ghana, air pollution due to gold mining is the least investigated. In order to obtain preliminary information on air quality in the mining areas, the generalized ko- Standardization neutron activation analysis (NAA) method for nuclides following '1/v' and non-'1/v' (n,γ) reactions was used to analyse lichen samples from Prestea, a gold mining area in Ghana. Using the computed EPI values of both the Hogdahl-convention and the modified Westcott-formalism with gold as comparator standard, the IAEA lichen 336 certified reference material (CRM) and the lichen samples were irradiated in the inner irradiation site of the Ghana Research Reactor-1 (GHARR-1) operating at a thermal neutron flux of 5.0x1011ns-1cm-2. Comparison of the results with samples obtained from a non-mining (control) area, indicates that values of some metal pollutants such as As, Cr, Sb, and V were found to be higher in the lichens from the mining area than those in the non-mining area (control area); signifying accumulation of these metal pollutant due to gold - mining activities. (author)

  5. Overview of ozone human exposure and health risk analyses used in the U.S. EPA's review of the ozone air quality standard.

    Energy Technology Data Exchange (ETDEWEB)

    Whitfield, R. G.

    1999-03-04

    This paper presents an overview of the ozone human exposure and health risk analyses developed under sponsorship of the U.S. Environmental Protection Agency (EPA). These analyses are being used in the current review of the national ambient air quality standards (NAAQS) for ozone. The analyses consist of three principal steps: (1) estimating short-term ozone exposure for particular populations (exposure model); (2) estimating population response to exposures or concentrations (exposure-response or concentration-response models); and (3) integrating concentrations or exposure with concentration-response or exposure-response models to produce overall risk estimates (risk model). The exposure model, called the probabilistic NAAQS exposure model for ozone (pNEM/03), incorporates the following factors: hourly ambient ozone concentrations; spatial distribution of concentrations; ventilation state of individuals at time of exposure; and movement of people through various microenvironments (e.g., outdoors, indoors, inside a vehicle) of varying air quality. Exposure estimates are represented by probability distributions. Exposure-response relationships have been developed for several respiratory symptom and lung function health effects, based on the results of controlled human exposure studies. These relationships also are probabilistic and reflect uncertainties associated with sample size and variability of response among subjects. The analyses also provide estimates of excess hospital admissions in the New York City area based on results from an epidemiology study. Overall risk results for selected health endpoints and recently analyzed air quality scenarios associated with alternative 8-hour NAAQS and the current 1-hour standard for outdoor children are used to illustrate application of the methodology.

  6. Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Sadowski, R.S.; Brown, M.J.; Harriz, J.T.; Ostrowski, E.

    1991-01-01

    The cost estimate provided for the DOE sponsored study of Air Blown Coal Gasification was developed from vendor quotes obtained directly for the equipment needed in the 50 MW, 100 MW, and 200 MW sized plants and from quotes from other jobs that have been referenced to apply to the particular cycle. Quotes were generally obtained for the 100 MW cycle and a scale up/down factor was used to generate the cost estimates for the 200 MW and 50 MW cycles, respectively. Information from GTPro (property of Thermoflow, Inc.) was used to estimate the cost of the 200 MW and 50 MW gas turbine, HRSG, and steam turbines. To available the use of GTPro's estimated values for this equipment, a comparison was made between the quotes obtained for the 100 MW cycle (ABB GT 11N combustion turbine and a HSRG) against the estimated values by GTPro.

  7. Survey of image quality and patient dose in simple radiographic examinations: establishing guidance levels and comparison with international standards

    International Nuclear Information System (INIS)

    Purpose: To investigate image quality and patient dose for commonly radiographic examinations in Thailand, to establish national reference or guidance levels (GL) and compare with international standards, as part of an International Atomic Energy Agency (IAEA) project on Radiation Protection of Patients and Medical Exposure Control (RAS/9/034 and RAS/9/047). Materials and Methods: Film reject rate analysis, image quality and patient dose assessment before and after Quality Control (QC) implementation were investigated in 8 X-ray machines in 4 hospitals. Air kerma (in mGy) at 1 meter focus-detector-distance for different kVp settings for each X-ray machines were measured using an ionization chamber under standardized condition. The entrance skin air kerma (ESAK) for Chest PA, Lumbar spine AP, Lumbar spine LAT, Pelvis AP, Abdomen AP, Skull AP and Skull LAT were calculated for at least 10 adult patients of average body mass (60 to 80 kg) for each projection. The obtained values were compared with international standards. Results: The highest film rejection rate reduction recorded after corrective actions from 9.15% to 6.8%. Mean ESAK values were less than international standards both before and after QC implementation in all projections but Chest PA projection. Maximum ESAK in Chest PA projection before corrective action was 0.55 mGy which was higher than the IAEA GL of 0.2 mGy. However, it was reduced to 0.25 mGy after QC tests on X- ray machine and using high kilovoltage (kV) technique. Conclusion: Proposed national GL of Thailand were obtained by estimating the 3rd quartile of the whole sample: Chest PA: 0.1 mGy, Lumbar Spine AP: 2.1 mGy, Lumbar Spine LAT: 6.3 mGy, Pelvis AP: 1.8 mGy, Abdomen: 1.5 mGy, Skull PA: 1.3 mGy and Skull LAT: 0.9 mGy. (author)

  8. Survey of image quality and patient dose in simple radiographic examinations: Establishing guidance levels and comparison with international standards

    International Nuclear Information System (INIS)

    Purpose: To investigate image quality and patient dose for commonly radiographic examinations in Thailand, to establish national reference or guidance levels (GL) and compare with international standards, as part of an International Atomic Energy Agency (IAEA) project on Radiation Protection of Patients and Medical Exposure Control (RAS/9/034 and RAS/9/047). Materials and Methods: Film reject rate analysis, image quality and patient dose assessment before and after Quality Control (QC) implementation were investigated in 8 X-ray machines in 4 hospitals. Air kerma (in mGy) at 1 meter focus-detector-distance for different kVp settings for each X-ray machines were measured using an ionization chamber under standardized condition. The entrance skin air kerma (ESAK) for Chest PA, Lumbar spine AP, Lumbar spine LAT, Pelvis AP, Abdomen AP, Skull AP and Skull LAT were calculated for at least 10 adult patients of average body mass (60 to 80 kg) for each projection. The obtained values were compared with international standards. Results: The highest film rejection rate reduction recorded after corrective actions from 9.15% to 6.8%. Mean ESAK values were less than international standards both before and after QC implementation in all projections but Chest PA projection. Maximum ESAK in Chest PA projection before corrective action was 0.55 mGy which was higher than the IAEA GL of 0.2 mGy. However, it was reduced to 0.25 mGy after QC tests on X-ray machine and using high kilovoltage (kV) technique. Conclusion: Proposed national GL of Thailand were obtained by estimating the 3rd quartile of the whole sample: Chest PA: 0.1 mGy, Lumbar Spine AP: 2.1 mGy, Lumbar Spine LAT: 6.3 mGy, Pelvis AP: 1.8 mGy, Abdomen: 1.5 mGy, Skull PA: 1.3 mGy and Skull LAT: 0.9 mGy. (author)

  9. Calculation of the backscattering in water and compared to the values in air; Calculo del factor de retrodispersion en agua y comparativa con los valores en aire

    Energy Technology Data Exchange (ETDEWEB)

    Minano Herrero, J. A.; Sarasa Rubio, A.; Roldan Arjona, J. M.

    2011-07-01

    The purpose of this paper is to calculate values of BSF in water and comparison with data on air 11SF found in the literature. For this simulations have been performed by the Monte Carlo method for calculating values ??kerma water in the presence of a manikin of this material and in the absence thereof. The simulations were performed for monoenergetic beams in order to facilitate the calculation of the BSF for any spectral distribution of those found in the field of radiology.

  10. International symposium on standards and codes of practice in medical radiation dosimetry. Book of extended synopses

    International Nuclear Information System (INIS)

    The development of radiation measurement standards by National Metrology Institutes (NMIs) and their dissemination to Secondary Standard Dosimetry Laboratories (SSDLs), cancer therapy centres and hospitals represent essential aspects of the radiation dosimetry measurement chain. Although the demands for accuracy in radiotherapy initiated the establishment of such measurement chains, similar traceable dosimetry procedures have been implemented, or are being developed, in other areas of radiation medicine (e.g. diagnostic radiology and nuclear medicine), in radiation protection and in industrial applications of radiation. In the past few years the development of primary standards of absorbed dose to water in 60Co for radiotherapy dosimetry has made direct calibrations in terms of absorbed dose to water available in many countries for the first time. Some laboratories have extended the development of these standards to high energy photon and electron beams and to low and medium energy x-ray beams. Other countries, however, still base their dosimetry for radiotherapy on air kerma standards. Dosimetry for conventional external beam radiotherapy was probably the field where standardized procedures adopted by medical physicists at hospitals were developed first. Those were related to exposure and air kerma standards. The recent development of Codes of Practice (or protocols) based on the concept of absorbed dose to water has led to changes in calibration procedures at hospitals. The International Code of Practice for Dosimetry Based on Standards of Absorbed Dose to Water (TRS 398) was sponsored by the International Atomic Energy Agency (IAEA), World Health Organization (WHO), Pan-American Health Organization (PAHO) and the European Society for Therapeutic Radiology and Oncology (ESTRO) and is expected to be adopted in many countries worldwide. It provides recommendations for the dosimetry of all types of beams (except neutrons) used in external radiotherapy and satisfies

  11. What is the explanation for the changes to cobalt-60 tissue - air ratios in BJR Supplement 25?

    International Nuclear Information System (INIS)

    Values of tissue - air ratio (TAR) in the recent British Journal of radiology (BJR) Supplement 25 have been increased by nearly 2% over the values which have been accepted for the past 30 years. The need for this was shown by analysis of previous data using scaling laws, together with Monte Carlo calculations and careful re-measurement. However, it was not clear why previous determinations of TAR were in error: it was not, as some workers argued, because scattered radiation had been included in the absorbed dose in the miniphantom, because TAR data in BJR Supplement 17 had been derived from peak scatter factor (PSF), which is not based on the miniphantom concept. The purpose of this paper is to find the real explanation of why the PSF and, therefore, TAR were underestimated for so long. Two definitions of PSF are considered: one based on kerma and one based on dose. This paper relates PSF of either definition to measurements of air kerma by including in the derivation the scatter in the plug which replaces the chamber when it has been removed from the surface of the water phantom. The kerma-based PSF is found to be 2% higher than the simple ratio of chamber readings in phantom and in air. The value of the dose-based definition agrees with that of the Kerma-based definition to within 0.2%. It is the scatter in the replacement plug in the surface of the water phantom which was effectively ignored by previous workers, and which explains the underestimates of around 2% in PSF nd TAR. The value of the dose-based PSF differs slightly from that of the Kerma-based PSF because of the different distributions of primary and scatter photon fluence. (author)

  12. Performance Optimization of an Air-Standard Irreversible Dual-Atkinson Cycle Engine Based on the Ecological Coefficient of Performance Criterion

    Directory of Open Access Journals (Sweden)

    Guven Gonca

    2014-01-01

    Full Text Available This paper presents an ecological performance analysis and optimization for an air-standard irreversible Dual-Atkinson cycle (DAC based on the ecological coefficient of performance (ECOP criterion which includes internal irreversibilities, heat leak, and finite-rate of heat transfer. A comprehensive numerical analysis has been realized so as to investigate the global and optimal performances of the cycle. The results obtained based on the ECOP criterion are compared with a different ecological function which is named as the ecologic objective-function and with the maximum power output conditions. The results have been attained introducing the compression ratio, cut-off ratio, pressure ratio, Atkinson cycle ratio, source temperature ratio, and internal irreversibility parameter. The change of cycle performance with respect to these parameters is investigated and graphically presented.

  13. Autocorrelation standard deviation and root mean square frequency analysis of polymer electrolyte membrane fuel cell to monitor for hydrogen and air undersupply

    Science.gov (United States)

    Kim, Joo Gon; Mukherjee, Santanu; Bates, Alex; Zickel, Benjamin; Park, Sam; Son, Byung Rak; Choi, Jae Sung; Kwon, Osung; Lee, Dong Ha; Chung, Hyun-Youl

    2015-12-01

    Proton exchange membrane fuel cells are a promising energy conversion device which can help to solve urgent environmental and economic problems. Among the various types of fuel cells, the air breathing proton exchange membrane fuel cell, which minimizes the balance of plant, has drawn a lot of attention due to its superior energy density. In this study a compact, air breathing, proton exchange membrane fuel cell based on Nafion and a Pt/C membrane electrode assembly was designed. The fuel cell was tested using a Scribner Associates 850e fuel cell test station. Specifically, the hydrogen fuel and oxygen starvation of the fuel cell were accurately and systematically tested and analyzed using a frequency analysis method which can analyze the input and output frequency. The analysis of the frequency variation under a fuel starvation condition was done using RMSF (root mean square frequency) and ACSD (autocorrelation standard deviation). The study reveals two significant results: first, the fuel starvations show entirely different phenomenon in both RMSF and ACSD and second, the results of the Autocorrelation show clearer results for fuel starvation detection than the results with RMSF.

  14. Summary of efficiency testing of standard and high-capacity high-efficiency particulate air filters subjected to simulated tornado depressurization and explosive shock waves

    International Nuclear Information System (INIS)

    Pressure transients in nuclear facility air cleaning systems can originate from natural phenomena such as tornadoes or from accident-induced explosive blast waves. This study was concerned with the effective efficiency of high-efficiency particulate air (HEPA) filters during pressure surges resulting from simulated tornado and explosion transients. The primary objective of the study was to examine filter efficiencies at pressure levels below the point of structural failure. Both standard and high-capacity 0.61-m by 0.61-m HEPA filters were evaluated, as were several 0.2-m by 0.2-m HEPA filters. For a particular manufacturer, the material release when subjected to tornado transients is the same (per unit area) for both the 0.2-m by 0.2-m and the 0.61-m by 0.61-m filters. For tornado transients, the material release was on the order of micrograms per square meter. When subjecting clean HEPA filters to simulated tornado transients with aerosol entrained in the pressure pulse, all filters tested showed a degradation of filter efficiency. For explosive transients, the material release from preloaded high-capacity filters was as much as 340 g. When preloaded high-capacity filters were subjected to shock waves approximately 50% of the structural limit level, 1 to 2 mg of particulate was released

  15. Evaluated cross section libraries and kerma factors for neutrons up to 100 MeV on 40Ca and 31P

    International Nuclear Information System (INIS)

    The authors present evaluations of the interaction of 20 to 100 MeV neutrons with calcium and phosphorus, which follows on from the previous work on carbon, nitrogen, and oxygen. The aim is to accurately represent integrated cross sections, inclusive emission spectra, and kerma factors, in a data library which can be used in radiation transport calculations. They apply the GNASH nuclear model code, which includes Hauser-Feshbach, preequilibrium, and direct reaction mechanisms, and use experimental measurements to optimize the calculations. Total, elastic, and nonelastic cross sections, angle-energy correlated emission spectra for light ejectiles with A ≤ 4 and gamma-rays, and average energy depositions, are determined. The expected accuracy of the calculated cross sections and kerma factors is discussed

  16. Evaluated cross section libraries and kerma factors for neutrons up to 100 MeV on 16O and 14N

    International Nuclear Information System (INIS)

    We present evaluations of the interaction of 20 to 100 MeV neutrons with oxygen and nitrogen nuclei, which follows on from our previous work on carbon. Our aim is to accurately represent integrated cross sections, inclusive emission spectra, and kerma factors, in a data library which can be used in radiation transport calculations. We apply the FKK-GNASH nuclear model code, which includes Hauser-Feshbach, preequilibrium, and direct reaction mechanisms, and use experimental measurements to optimize the calculations. We determine total, elastic, and nonelastic cross sections, angle-energy correlated emission spectra, for light ejectiles with A≤4 and gamma-rays, and average energy depositions. Our results for charged-particle emission spectra agree well with the measurements of Subramanian et al.. We compare kerma factors derived from our evaluated cross sections with experimental data, providing an integral benchmarking of our work. The evaluated data libraries are available as electronic files

  17. Calculation and evaluation of cross-sections and kerma factors for neutrons up to 100 MeV on {sup 16}O and {sup 14}N

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B. [California Univ., Livermor, CA (United States). Lawrence Livermore National Lab.; Young, P.G.

    1997-03-01

    We present evaluations of the interaction of neutrons with energies between 20 and 100 MeV with oxygen and nitrogen nuclei, which follows on from our previous work on carbon. Our aim is to accurately represent integrated cross sections, inclusive emission spectra, and kerma factors, in a data library which can be used in radiation transport calculations. We apply the FKK-GNASH nuclear model code, which includes Hauser-Feshbach, preequilibrium, and direct reaction mechanisms, and use experimental measurements to optimize the calculations. We determine total, elastic, and nonelastic cross sections, angle-energy correlated emission spectra for light ejectiles with A {<=} 4 and gamma-rays, and average energy depositions. Our results for charged-particle emission spectra agree well with the measurements of Subramanian et al. We compare kerma factors derived from our evaluated cross sections with experimental data, providing an integral benchmarking of our work. (author). 52 refs.

  18. Quality management system of secondary standards dosimetry laboratory in Sri Lanka

    International Nuclear Information System (INIS)

    ). This network provides assistance for members to maintain consistency of Radiation Standard measurements in their dosimetry laboratories. Reference electrometer with ion-chambers has been calibrated from IAEA Radiation Standard Laboratory at Seibersdorf in Austria which is traceable to primary standards at BIPM. Measuring standards are calibrated using these reference standards. The SSDL also participates IAEA TLD dose audit program to ensure the accuracy of radiation standards and is firmly committed to achieve global harmonization wherever possible. Hence the QMS assures the quality and accuracy of the services provided to institutions such as hospitals, research institutes, industries for the safety of their radiation workers. Reference electrometer with ion-chambers is used to standardize the gamma radiation fields. Measurements are made from 1 m onwards from the source with 25 cm step increment along the beam axis. Ten consecutive readings are taken for the measurement of air-kerma rate at a point. Ambient temperature, pressure and humidity at the beginning and end of measurements of each measurement are taken by using calibrated ancillary instruments, which are traceable to national and international standards, for correction of density of air mass in the ion-chamber. This air-kerma rate is converted to ambient dose equivalent rate (ADER) for the calibration of area monitors and personal dose equivalent rate (PDER) for calibration of personal monitoring instruments/devices as recommended in IAEA Safety Report Series 16. Graphs, Distance Vs dose rate for ADER and PDER using power fitting formula are established. Decay correction is applied for each data point measured and a fresh graph, Distance Vs dose rate is prepared each day prior to calibration of instruments. Verification of dose given by the software program is done with manual calculation of three data points. Energies of X-ray beams used for protection level calibration are verified with first and second

  19. Balancing energy conservation and occupant needs in ventilation rate standards for Big Box stores and other commercial buildings in California. Issues related to the ASHRAE 62.1 Indoor Air Quality Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Apte, Mike G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2010-10-31

    This report considers the question of whether the California Energy Commission should incorporate the ASHRAE 62.1 ventilation standard into the Title 24 ventilation rate (VR) standards, thus allowing buildings to follow the Indoor Air Quality Procedure. This, in contrast to the current prescriptive standard, allows the option of using ventilation rate as one of several strategies, which might include source reduction and air cleaning, to meet specified targets of indoor air concentrations and occupant acceptability. The research findings reviewed in this report suggest that a revised approach to a ventilation standard for commercial buildings is necessary, because the current prescriptive ASHRAE 62.1 Ventilation Rate Procedure (VRP) apparently does not provide occupants with either sufficiently acceptable or sufficiently healthprotective air quality. One possible solution would be a dramatic increase in the minimum ventilation rates (VRs) prescribed by a VRP. This solution, however, is not feasible for at least three reasons: the current need to reduce energy use rather than increase it further, the problem of polluted outdoor air in many cities, and the apparent limited ability of increasing VRs to reduce all indoor airborne contaminants of concern (per Hodgson (2003)). Any feasible solution is thus likely to include methods of pollutant reduction other than increased outdoor air ventilation; e.g., source reduction or air cleaning. The alternative 62.1 Indoor Air Quality Procedure (IAQP) offers multiple possible benefits in this direction over the VRP, but seems too limited by insufficient specifications and inadequate available data to provide adequate protection for occupants. Ventilation system designers rarely choose to use it, finding it too arbitrary and requiring use of much non-engineering judgment and information that is not readily available. This report suggests strategies to revise the current ASHRAE IAQP to reduce its current limitations. These

  20. Evaluated cross-section libraries and kerma factors for neutrons up to 100 MeV on 12C

    International Nuclear Information System (INIS)

    A program is being carried out at Lawrence Livermore National Laboratory to develop high-energy evaluated nuclear data libraries for use in Monte Carlo simulations of cancer radiation therapy. In this report we describe evaluated cross sections and kerma factors for neutrons with incident energies up to 100 MeV on 12C. The aim of this effort is to incorporate advanced nuclear physics modeling methods, with new experimental measurements, to generate cross section libraries needed for an accurate simulation of dose deposition in fast neutron therapy. The evaluated libraries are based mainly on nuclear model calculations, benchmarked to experimental measurements where they exist. We use the GNASH code system, which includes Hauser-Feshbach, preequilibrium, and direct reaction mechanisms. The libraries tabulate elastic and nonelastic cross sections, angle-energy correlated production spectra for light ejectiles with A≤and kinetic energies given to light ejectiles and heavy recoil fragments. The major steps involved in this effort are: (1) development and validation of nuclear models for incident energies up to 100 MeV; (2) collation of experimental measurements, including new results from Louvain-la-Nueve and Los Alamos; (3) extension of the Livermore ENDL formats for representing high-energy data; (4) calculation and evaluation of nuclear data; and (5) validation of the libraries. We describe the evaluations in detail, with particular emphasis on our new high-energy modeling developments. Our evaluations agree well with experimental measurements of integrated and differential cross sections. We compare our results with the recent ENDF/B-VI evaluation which extends up to 32 MeV

  1. Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 1, Methodology

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    The Energy Policy and Conservation Act (P.L. 94-163), as amended, establishes energy conservation standards for 12 of the 13 types of consumer products specifically covered by the Act. The legislation requires the Department of Energy (DOE) to consider new or amended standards for these and other types of products at specified times. DOE is currently considering amending standards for seven types of products: water heaters, direct heating equipment, mobile home furnaces, pool heaters, room air conditioners, kitchen ranges and ovens (including microwave ovens), and fluorescent light ballasts and is considering establishing standards for television sets. This Technical Support Document presents the methodology, data, and results from the analysis of the energy and economic impacts of the proposed standards. This volume presents a general description of the analytic approach, including the structure of the major models.

  2. Human occupations and environmental changes in the Nile valley during the Holocene: The case of Kerma in Upper Nubia (northern Sudan)

    Science.gov (United States)

    Honegger, Matthieu; Williams, Martin

    2015-12-01

    Our article presents a detailed Holocene archaeological sequence from the Nile Valley at Kerma in Upper Nubia, northern Sudan. This sequence retraces the evolution of human populations thanks to the study of several sites, supported by 90 14C dates. Reconstruction of the environmental changes was supported by a study of dated stratigraphic sections located near the archaeological sites studied, and illustrates the effects on human occupation of changes in river flow and floods, which are in turn forced by climatic changes. The results shed new light on the evolutionary dynamics of the Holocene populations in Nile Valley, little known due to the numerous hiatuses in occupation. When compared with the situation in the Sahara and the rest of the Nile Valley, they confirm that the initial occupation took place ca. 10.5 kyr BP after the start of the African Humid Period, followed by a migration towards the banks of the Nile commencing 7.3 kyr BP. They also confirm the appearance of the Neolithic by ca. 8.0 kyr BP. The Kerma stratigraphic sequences show two prosperous periods (10-8 and 7-6 kyr BP) and two hiatuses in the occupation of the sites (7.5-7.1 and 6.0-5.4 kyr BP), resulting from increased aridity.

  3. Evaluation of cross sections and calculation of kerma factors for neutrons up to 80 MeV on {sup 12}C

    Energy Technology Data Exchange (ETDEWEB)

    Harada, M.; Watanabe, Y. [Kyushu Univ., Fukuoka (Japan); Chiba, S.; Fukahori, T.

    1997-03-01

    We have evaluated the cross sections for neutrons with incident energies from 20 to 80 MeV on {sup 12}C for the JENDL high-energy file. The total cross sections were determined by a generalized least-squares method with available experimental data. The cross sections of elastic and inelastic scattering to the first 2{sup +} were evaluated with the theoretical calculations. The optical potentials necessary for these calculations were derived using a microscopic approach by Jeukenne-Lejeune-Mahaux. For the evaluation of double differential emission cross sections (DDXs), we have developed a code system SCINFUL/DDX in which total 35 reactions including the 3-body simultaneous breakup process (n+{sup 12}C {yields} n+{alpha}+{sup 8}Be) can be taken into consideration in terms of a Monte Carlo method, and have calculated the DDXs of all light-emissions (A{<=}4) and heavier reaction products. The results for protons, deuterons, and alphas showed overall good agreement with experimental data. The code is also applicable for calculations of total and partial kerma factors. Total kerma factors calculated for energies from 20 to 80 MeV were compared with the measurements and the other latest evaluations from the viewpoints of medical application and nuclear heating estimation. (author)

  4. Analytic And Monte Carlo Study Of The Perturbation Factor kp For A Standard Of Dw Through An Ka Standard Ionization Chamber BEV-CC01

    International Nuclear Information System (INIS)

    To characterize an ionization chamber BEV-CC01 as a standard of absorbed dose to water Dw at SSDL-Mexico, the approach developed by the BIPM for 60Co gamma radiation, has been chosen. This requires the estimation of a factor kp, which stems from the perturbation introduced by the presence of the ionization chamber in the water phantom, and due to finite size of the cavity. This factor is the product of four terms: ψw,c (μen/ρ)w,c (1 + μ'.y-bar)w,c and kcav. Two independent determinations are accomplished using a combination of the Monte Carlo code MCNP4C in ITS mode [2,3] and analytic methods: one kp parallel =1.1626 ± uc=: 0.90% for the chamber axis parallel to the beam axis; and another kp =1.1079± uc=0.89% for the chamber axis perpendicular to the beam axis. The variance reduction techniques: splitting-Russian roulette, source biasing and forced photon collisions are employed in the simulations to improve the calculation efficiency. The energy fluence for the 60Co housing-source Picker C/9 is obtained by realistic Monte Carlo (MC) simulation, it is verified by comparison of MC calculated and measured beam output air kerma factors, and percent depth dose curves in water, PDD. This spectrum is considered as input energy for a point source (74% is from primary photons and the rest 26% is from scattered radiation) in the determination of the kp factors. Details of the calculations are given together with the theoretical basis of the ionometric standard employed

  5. Modalities of PM10 and PM2.5 Quantification in Environmental Air Using the Standardized Method

    OpenAIRE

    I. OROIAN; Laura PAULETTE; C. IEDERAN; I. BRASOVEAN; P. BURDUHOS

    2009-01-01

    The distribution of PM10 and PM2.5 particles with respect to size is an important physical parameter affectingpublic health. During January – February 2009, a trial was developed. It aimed the quantification of the PM10 and PM2.5particles from the air in the University of Agricultural Sciences and Veterinary Medicine Cluj – Napoca, using thefacilities of the mobile Laboratory of Air Quality Control. The particulate matter was gravimetrically quantifiedaccording to the stipulations of the SR E...

  6. Hazardous air pollutant emissions from process units in the synthetic organic chemical manufacturing industry: Background information for proposed standards. Volume 1C. Model emission sources. Draft report

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    A draft rule for the regulation of emissions of organic hazardous air pollutants (HAP's) from chemical processes of the synthetic organic chemical manufacturing industry (SOCMI) is being proposed under the authority of Sections 112, 114, 116, and 301 of the Clean Air Act, as amended in 1990. The volume of the Background Information Document presents model emission sources that were developed to evaluate the national impacts of the proposed rule.

  7. Environmental health and safety issues related to the use of low-level radioactive waste (LLRW) at hospitals and medical research institutions and compliance determination with the Clean Air Act standards

    International Nuclear Information System (INIS)

    Currently, the United States Nuclear Regulatory Commission (NRC) has standards for procedures, performance activities and technical specifications on storage of Low-Level Radioactive Waste (LLRW) under 10 CFR Part 20. The United States Environmental Protection Agency (EPA) is proposing environmental standards for the management, storage and disposal of LLRW. The proposed standards, which will become 40 CFR part 193 when finalized, limits the committed effective dose to members of the public from the management and storage of LLRW, committed effective doses resulting from LLRW disposal and levels of radiological contamination of underground sources of drinking water as a result of the activities subject to management, storage and disposal of LLRW. Further, under Title III of the Clean Air Act Amendments, radionuclides are required to be inventoried for all generators. For hospitals and medical research institutions, quantities of LLRW are often below the concentrations required under reporting and record keeping requirements of 10 CFR 20. However, in many instances, the facility may require NRC permits and compliance with air quality dispersion modeling requirements. This paper presents the typical radionuclides used in hospitals and medical research institutions, and strategies to evaluate their usage and steps to achieve compliance. Air quality dispersion modeling by use of the COMPLY model is demonstrated to evaluate the fate of radionuclides released from on-site incineration of LLRW. The paper concludes that no significant threat is posed from the incineration of LLRW

  8. Proficiency Testing as a tool to monitor consistency of measurements in the IAEA/WHO Network of Secondary Standards Dosimetry Laboratories

    Science.gov (United States)

    Meghzifene, Ahmed; Czap, Ladislav; Shortt, Ken

    2008-08-01

    The International Atomic Energy Agency (IAEA) and the World Health Organization (WHO) established a Network of Secondary Standards Dosimetry Laboratories (IAEA/WHO SSDL Network) in 1976. Through SSDLs designated by Member States, the Network provides a direct link of national dosimetry standards to the international measurement system of standards traceable to the Bureau International des Poids et Mesures (BIPM). Within this structure and through the proper calibration of field instruments, the SSDLs disseminate S.I. quantities and units. To ensure that the services provided by SSDL members to end-users follow internationally accepted standards, the IAEA has set up two different comparison programmes. One programme relies on the IAEA/WHO postal TLD service and the other uses comparisons of calibrated ionization chambers to help the SSDLs verify the integrity of their national standards and the procedures used for the transfer of the standards to the end-users. The IAEA comparisons include 60Co air kerma (NK) and absorbed dose to water (ND,W) coefficients. The results of the comparisons are confidential and are communicated only to the participants. This is to encourage participation of the laboratories and their full cooperation in the reconciliation of any discrepancy. This work describes the results of the IAEA programme comparing calibration coefficients for radiotherapy dosimetry, using ionization chambers. In this programme, ionization chambers that belong to the SSDLs are calibrated sequentially at the SSDL, at the IAEA, and again at the SSDL. As part of its own quality assurance programme, the IAEA has participated in several regional comparisons organized by Regional Metrology Organizations. The results of the IAEA comparison programme show that the majority of SSDLs are capable of providing calibrations that fall inside the acceptance level of 1.5% compared to the IAEA.

  9. Air kerma rate measurements of 192Ir source in Gammamed 12i HDR/PDR unit using well type ionization chamber

    International Nuclear Information System (INIS)

    The use of high dose rate (HDR) brachytherapy in radiotherapy department has increased nowadays. The initial activity of 192Ir sources, used in high dose rate brachytherapy unit is approximately 10 Ci. About 3 to 4 times per year, a replacement is made of these sources, because of the decay half-life of 192Ir with 73.83 days. It is recommended that each time a new HDR source is installed for use in clinical routine, a source calibration in the hospital should be carried out

  10. Conception and realization of a parallel-plate free-air ionization chamber for the absolute dosimetry of an ultrasoft X-ray beam

    International Nuclear Information System (INIS)

    We report the design of a millimeter-sized parallel plate free-air ionization chamber (IC) aimed at determining the absolute air kerma rate of an ultra-soft X-ray beam (E = 1.5 keV). The size of the IC was determined so that the measurement volume satisfies the condition of charged-particle equilibrium. The correction factors necessary to properly measure the absolute kerma using the IC have been established. Particular attention was given to the determination of the effective mean energy for the 1.5 keV photons using the PENELOPE code. Other correction factors were determined by means of computer simulation (COMSOL™and FLUKA). Measurements of air kerma rates under specific operating parameters of the lab-bench X-ray source have been performed at various distances from that source and compared to Monte Carlo calculations. We show that the developed ionization chamber makes it possible to determine accurate photon fluence rates in routine work and will constitute substantial time-savings for future radiobiological experiments based on the use of ultra-soft X-rays

  11. Comparison of dosimetric standards of Canada and France for photons at 60Co and higher energies

    International Nuclear Information System (INIS)

    We report the results of a comparison of the dosimetric standards of Canada and France for photon beams at 60Co and a few higher energies. The present primary standard of absorbed dose to water for NRC, Canada is based on measurements made with a sealed water calorimeter. The corresponding standard of the LNHB, France is based on measurements made with a graphite calorimeter at 60Co energy and transferred to absorbed dose to water for 60Co and higher-energy photon beams using both ion chambers and Fricke dosemeters as transfer instruments. To make this comparison, we used three graphite-walled NE2571 Farmer chambers. The absorbed dose to water determined by the LNHB was greater than that determined by NRC by 0.20% at 60Co energy. This difference is not significant given the uncertainties on the standards. In order to do the comparison for higher-energy photons, we interpolated the NRC data set at the beam qualities used at the LNHB. When %dd(10)x is used as the method of specifying beam quality, the determination of absorbed dose to water by the LNHB is about 0.2% greater than that determined by NRC and consistent with the results at 60Co. However, when using TPR20,10 as the beam quality specifier, the LNHB determination is greater than the NRC's determination by 0.8% and 1.2% at 12 and 20 MV respectively. This discrepancy, which systematically increases with increasing energy, eventually exceeds the uncertainties in the ratio of the standards, estimated to be 0.7%. This underscores the importance of selecting the method of specifying beam quality, either %dd(10)x or TPR20,10, at least for the 'soft' beams used by NRC in this comparison. In the case of the air kerma standards, which were also compared at 60Co energy, the LNHB determination was greater than NRC's by 0.14%, which is not significant given the uncertainties on the standards. (author)

  12. A Prototype Ionisation Chamber as a Secondary Standard for the Measurement of Personal Dose Equivalent, Hp(10), on a Slab Phantom

    International Nuclear Information System (INIS)

    The construction and technical characteristics of a secondary standard chamber for measuring the conventionally true value of the personal dose equivalent, Hp(10), on a slab phantom are presented. The chamber was optimised to get a nearly constant response with respect to Hp(10) for photon energies from about 10 keV to 1400 keV and for angles of incidence, alpha, from 0 deg. to 75 deg. . Thus, once calibrated at the facility of the calibration laboratory, the Hp(10) chamber can be used at other facilities without any need to consider the spectral differences of radiation fields of the same nominal radiation quality but generated by two different facilities. This is a great advantage over the procedure recommended in ISO/FDIS 4037-3, according to which these differences have to be considered for low energy photon radiation and may lead to differences of the conversion coefficients from air kerma, Ka, to Hp(10) of up to several tens of per cent. (author)

  13. Calculation of conversion coefficients Hp(3)/K air using the PENELOPE Monte Carlo code and comparison with MCNP calculation results

    International Nuclear Information System (INIS)

    The authors report calculations performed using the MNCP and PENELOPE codes to determine the Hp(3)/K air conversion coefficient which allows the Hp(3) dose equivalent to be determined from the measured value of the kerma in the air. They report the definition of the phantom, a 20 cm diameter and 20 cm high cylinder which is considered as representative of a head. Calculations are performed for an energy range corresponding to interventional radiology or cardiology (20 keV-110 keV). Results obtained with both codes are compared

  14. Analysis of air pollution in two major Korean cities: trends, seasonal variations, daily 1-hour maximum versus other hour-based concentrations, and standard excedances

    International Nuclear Information System (INIS)

    This study considers the characteristics of carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3) and sulfur dioxide (SO2) in two major South Korean cities, including the capital city of Seoul, over a time period of 7-8 years. Changes in the annual mean and percentiles of the daily 1-h maximum and other hour-based concentrations varied according to the compound and city type. Seasonal variations varied according to the compound, yet not with the city type. Both Seoul and Taegu exhibited lower O3 concentrations in July compared to other summer months. There was a high degree of correlation between the daily 1- and 8-h maximum or daily mean concentrations of all compounds in both cities, with an R2 of 0.66-0.90 at p 3, the 8-h standard was more stringent than the 1-h standard, while for NO2 and SO2, the 1-h standard was more stringent than the 24-h standard. The correlation coefficients between the daily 1-h maximum and daily mean concentrations decreased as the maximum concentration values of NO2, O3 , and SO2 increased in the two cities. For all the target compounds, Seoul recorded a substantially higher frequency of days with concentrations above the relevant 1-, 8-, and 24-h standards compared to Taegu. (author)

  15. Air pollution abatement by means of energy-efficient building construction. Passive standard buildings, a student's competition; Klimaschutz durch energieeffizientes Bauen. Passivhausstandard im studentischen Wettbewerb

    Energy Technology Data Exchange (ETDEWEB)

    Michel, U.; Scherer, U. [Hannover Univ. (Germany). Inst. fuer Entwerfen und Konstruieren

    2005-07-01

    In order to make students aware of the potential for energy conservation in the building sector, the Architecture and Landscape Department, in cooperation with the enercity-Fund proKlima initiated student's competitions in passive-standard building construction. The programme started in winter 2002/2003. (orig.)

  16. Advisory Committee for the Calibration Standards of Ionizing Radiation Measurement

    International Nuclear Information System (INIS)

    An account of the activity during the past two years and of the plans for future work is given for the three Sections of the Comite Consultatif pour les Etalons de Mesure des Rayonnements Ionisants. Section I (Rayons X et #betta#, electrons) studied in detail the results of an intercomparison of Frike dosimeters. A recommendation was made concerning the possibility of expressing calibrations made in terms of exposure in terms of air kerma or water kerma. Section II (Mesure des radionucleides) studied the results of recent international comparisons (55Fe, 133Ba and 134Cs) and made plans for new ones. Section III (Mesures neutroniques) presented the status of the international comparisons of neutron fluence rate in progress and decided to organize new ones. The reports of the Section chairmen are followed by the presentation of the work carried out at BIPM by the corresponding groups. The status of the proposal by Section III for a 14 MeV neutron dosimetry facility at BIPM is discussed in detail and a proposal is made for a neutron dosimetry intercomparison

  17. Calibration factors determination of a parallel plate chamber using a 60 Co in air method: a study of AAPM Protocol in comparison with the IAEA code of practice

    International Nuclear Information System (INIS)

    Besides the recently published IAEA Code of Practice (1997), there are also other protocols such as AAPM TG-39, HPA and NACP that have been used for the determination of parallel plate chamber calibration factors, namely the air kerma calibration factor (NKPP), the exposure calibration factor (NXPP) and ,the absorbed dose to air chamber factor (ND,airPP using a 60Co in-air method. This preliminary work is to determine those three calibration factors with the use of IAEA Code of Practice (1997) and AAPM TG-39 (1994) protocol. The results obtained from both protocols were then compared. A parallel plate chamber PTW-Freiburg of type 34001 was used. It was calibrated against a secondary standard NE Farmer cylindrical type chamber 2571. A 60Co unit ELDORADO 8nr.104 was used. The calibration was performed in air with a source to chamber distance (SCD) of 100 cm and a field size of 10 cm x 10 pp pp cm at SCD. Using the IAEA Code of Practice the values of NKPP, NXPP and ND,airPP were found to be 101.7702 mGy/nC, 11.5784 R/nC and 99.9429 mGy/nC respectively, while using the AAPM protocol these values were found to be 101.7718 mGy/nC, 11.5787 R/nC and 99.8538 mGy/nC respectively. The random uncertainties at 95% confidence level for all the calibration factors obtained were in a range of +0.04% to +0.07%. In comparison with the IAEA Code of Practice, the AAPM protocol gave deviations of +0.002% for NKPP, +0.003% for NXPP and -0.089% for theND,airPP. These good agreements of NKPP, NXPP and ND,airPP implied that both protocols could be treated as equivalent. Studies of the other protocols will be carried out later in the near future. (author)

  18. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, ... a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  19. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, ...

  20. Experimental research in the use of electrets in measuring effluents from rocket exhaust and a review of standard air quality measuring devices

    Science.gov (United States)

    Susko, M.

    1976-01-01

    Seven standard types of measuring devices used to obtain the chemical composition of rocket exhaust effluents were discussed. The electrets, a new measuring device, are investigated and compared with established measuring techniques. The preliminary results obtained show that electrets have multipollutant measuring capabilities, simplicity of deployment, speed of assessment or analysis, and may be an important and valuable tool in measuring pollutants from space vehicle rocket exhaust.