RESULTS OF THE REGIONAL INTERCOMPARISON EXERCISE FOR THE DETERMINATION OF OPERATIONAL QUANTITY H P (10) IN LATIN AMERICA M. Saravı ´ 1, , A. Zaretzky 1 , C. Lindner 1 , J. Dı ´az 2 , G. Walwyn 3 , R. Amorim 4 , D. De Souza 4 , B. Gregori 5 , S. Papado´ pulos 5 , A. Meghzifene 6 , P. Ferruz 6 and R. Cruz Sua´rez 6 1 Comisio´ n Nacional de Energı ´a Ato´ mica (CNEA), and Centro Ato´ mico Ezeiza, Pbro. J. Gonza´lez Y Arago´ n N 15. B1802AYA, Ezeiza, Argentina 2 Instituto Venezolano de Investigaciones Cientı ´ficas (IVIC), Venezuela 3 Centro de Proteccio´ n e Higiene de las Radiaciones (CPHR), Cuba 4 Instituto de Radioproteccio´ n e Dosimetrı ´a (IRD), Brazil 5 Autoridad Regulatoria Nuclear (ARN), Argentina 6 International Atomic Energy Agency (IAEA), Austria Several intercomparison exercises were organised by the International Atomic Energy Agency (IAEA) on the determination of operational quantities at the regional or interregional basis. In the Latin American region an intercomparison for the determination of the operational quantity H p (10) was completed mid-2004, as a follow-up to previous exercises carried out during the 1990s. Eighteen individual external monitoring services from nineteen Member States participated in the first phase. The second phase grouped 15 services that had participated in the first phase. Dosemeter irradiations in photon beams were done by four Secondary Standard Dosimetry Laboratories (SSDLs) of the region. The preparation of this exercises involved an audit by the IAEA SSDL, where reference irradiations were provided to all participants for verification of their systems. During the first phase (2002–2003) only 9 out of 18 services met the performance requirements for such monitoring services. Necessary corrective actions and procedure verification were implemented. During the second phase (2004) 11 out of 15 services fulfilled the performance criteria. This intercomparison shows that there has been improvement in the second phase and most participants demonstrated a satisfactory performance of the quantity tested. INTRODUCTION The international standards (1) recommend the use of operational quantities for the personal dosimetry, specially the personal dose equivalent H p (10). Due to technical difficulties to introduce the use of this quantity the IAEA assessed their Member States in order to promote their use. Between 1986 and 1999 the IAEA supported three dosimetry projects for intercomparison of external personal dosimetry in the region of Latin America. As part of the Agency’s strategy to strengthen the national infrastructure in relation with the control of workers that are occu- pationally exposed to ionising radiation, the IAEA organised, in year 2002, an intercomparison of exter- nal dosimetry services for its Member States of the Latin-American region that are participating in the IAEA Model Project RLA/9/041. The IAEA has seen the convenience that the Secondary Standard Dosimetry Laboratories (SSDLs) play an important role in the organisation of national or regional inter- comparison exercises. For this reason, the IAEA invited four SSDLs of the region to co-ordinate and lead such intercomparison. The objective of this intercomparison carried out from June 2002 to June 2004 was to evaluate the performance of individual external monitoring services in Latin America. Moreover, the exchange of technical information, calibration and essay, as well as, qual- ity assurance experiences within the participants was an objective too. The intercomparison was organised in three phases. During the first one, a follow-up of the cor- rect use of H p (10) in reference conditions was per- formed. The second phase was held to analyse the capability of the participating services to determine H p (10) under irradiation conditions nearer to real irradiation fields, with different incidence angles and different mixed radiation beam qualities. During the third and last phase, information and experiences about calibration and test of external dosimetry sys- tems and about implementation of QA programs were transferred to the participants. The results of the first and second phase of this intercomparison are described and discussed in this report. METHODS Tables 1 and 2 show the irradiation condi- tions employed during the first and second phase, respectively. The SSDLs from Argentina, Brazil, Cuba and Venezuela irradiated the dosemeters of participants. Prior to irradiation the IAEA Dosimetry Laboratory audited these SSDLs in terms of air kerma for 137 Cs  Corresponding author: saravi@cae.cnea.gov.ar Radiation Protection Dosimetry (2007), Vol. 125, No. 1–4, pp. 84–87 doi:10.1093/rpd/ncl538 Advance Access publication 19 December 2006 Ó The Author 2006. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org