Validation of a free release measurement facility on a decommissioning site.

The paper summarizes measurements and the Monte Carlo simulations performed to adapt the high purity germanium (HPGe) detectors of the system to the particular tasks of the decommissioning site. The work carried out for the installation and adaptation in CIEMAT of the prototype 'SuperMum', developed in the framework of the European MetroDecom II project for segregation and declassification of materials is described. The activities related to the validation of the prototype for the specific needs of a real Waste Management Unit are presented. Monte Carlo models of the SuperMum have been developed at CIEMAT and CMI using different codes and adapted to the geometries used (big-bag containers with the material volume of up to 0.5 m3). Uncertainty budget reporting tailored for the possible deviations between Monte Carlo assumptions and real waste have been analyzed. Data for several filling levels and activity distributions have been measured with reference sources and a good agreement has been obtained with calculated values.

Consistency test of coincidence-summing calculation methods for extended sources.

An internal consistency test of the calculation of coincidence-summing correction factors FC for volume sources is presented. The test is based on exact equations relating the values of FC calculated for three ideal measurement configurations. The test is applied to a number of 33 sets of FC values sent by 21 teams. Most sets passed the test, but not the results obtained using the quasi-point source approximation; in the latter case the test qualitatively indicated the magnitude of the bias of FC.

Activity measurements and determination of nuclear decay data of 166Ho in the MRTDosimetry project.

Holmium-166 is a high-energy ß--emitter radionuclide (~ 1.8 MeV) with a short half-life (~26.8h) that offers great potential as an alternative to 90Y for the treatment of liver cancer based on radioembolization. The possibility of quantitative Single Photon Emission Computed Tomography (SPECT) imaging of the main γ-ray emission at 80.6 keV, in addition to strong paramagnetic properties suitable for Magnetic Resonance Imaging (MRI), complement this therapeutic potential. The present paper describes the measurements carried out in three European radionuclide metrology laboratories for primary standardization of 166Ho and new determinations of X- and γ-ray photon-emission intensities in the framework of the European EMPIR project MRTDosimetry. New half-life measurements were also performed.

RADON CONCENTRATION IN THE AREA OF WASTE ROCK DUMPS, BROD, CR-CASE STUDY.

There are ~7000 mining waste storage facilities including waste rock dumps in the Czech Republic. One of the radiation protection present subjects is a health impact estimation of the huge mass of material in waste rock dumps left after uranium mining. In this document are presented selected results of waste rock dump long-term monitoring in the area of shaft No. 15 (Pribram, CR) and its estimated health impact to the representative person in a village Brod. The external irradiation was estimated based on in situ gamma spectrometry measurement results and on a Monte Carlo model and it turned out to be negligible (tens µSv), while the internal irradiation (RAMARN, ALGADE Environmental and RAMONIS detection systems) is more significant. The estimated total annual effective dose for representative person is mainly caused by indoor radon inhalation. The maximum outdoor radon concentration in summer season was measured during night hours between 9 p.m. and 7 a.m. and could reach thousands Bq/m3. The average indoor concentration measured in randomly selected houses was 450 Bq/m3. The radon exhalation rate was 35-40 mBq m-2 s-1.

New high-throughput measurement systems for radioactive wastes segregation and free release.

This paper addresses the measurement facilities for pre-selection of waste materials prior to measurement for repository acceptance or possible free release (segregation measurement system); and free release (free release measurement system), based on a single standardized concept characterized by unique, patented lead-free shielding. The key objective is to improve the throughput, accuracy, reliability, modularity and mobility of segregation and free-release measurement. This will result in a more reliable decision-making with regard to the safe release and disposal of radioactive wastes into the environment and, resulting in positive economic outcomes. The research was carried out within "Metrology for Decommissioning Nuclear Facilities" (MetroDecom) project.

MEASUREMENT OF SECONDARY NEUTRONS GENERATED DURING PROTON THERAPY.

Measurements described in this article were carried out with the aim of evaluating risks of the patient exposure to secondary neutrons during treatment at the Proton Therapy Centre Prague. The neutron spectral fluence was measured by means of the extended Bonner sphere spectrometer (EBS). The article presents secondary neutron spectral fluences obtained by the EBS with passive thermoluminescent detectors, i.e. pairs of 6LiF and 7LiF chips. Measurements were performed in two positions: the first one behind the Nylon 6 phantom, and the second one close to the range shifter to evaluate their contribution to the generation of neutrons. Both the Nylon 6 phantom and the range shifter were irradiated with a pencil beam of protons 4 mm in diameter and the energy of 200 MeV. The results are supplemented with the values of effective dose derived from neutron spectral fluences.

Combination of high-performance liquid chromatography and radioimmunoassay for the measurement of urodilatin and alpha-hANP in the urine of healthy males.

Urodilatin (ANP-(95-126)), a natriuretic peptide in urine, and alpha-hANP (ANP-(99-126)) are crossreactive in the radioimmunoassay of alpha-hANP (ANP-RIA). We therefore developed a method to separate physiological amounts of urodilatin and alpha-hANP in urine by high-performance liquid chromatography (HPLC) followed by ANP-RIA of the separated fractions. We studied urine samples of 10 healthy adult males with a plasma alpha-hANP level of 41 +/- 21 pg/ml (mean +/- SD) and a total urinary ANP-RIA reactivity of 40 +/- 21 pg/ml. In all urine samples we found three peaks of ANP-RIA reactivity, the first one coeluting with synthetic urodilatin, the second one with the retention time of alpha-hANP and a late eluting ANP-RIA-reactive peak, possibly containing degradation products. The ratio of urodilatin/alpha-hANP was 0.77 +/- 0.17.

Meatoplasty with reconstruction of the foreskin. A procedure for anterior hypospadias.

There is a growing awareness of normal outlook of the male genitalia. Described technique of meatoplasty with reconstruction of the foreskin is a relatively simple but safe method with satisfactory results, both functional and cosmetic, in cases of glandular, coronal and anterior penile hypospadias, applicable in the absence of fibrous chordee.

Our experience with operative treatment of malignant melanoma.

The result of studies of the series of patients with a malignant melanoma operated on radically and non-radically in our region was extended to include the time period from 1975 to 1983 and the new findings confirmed the results of our first study from 1983. No difference in the survival rate was found between the groups of radically and non-radically operated patients. The radicalness of the excision of a primary tumour does not influence the time of survival of the patients. This was also confirmed by the evaluation of the series of patients operated only with the non-radical method at our department during the recent years. On the basis of the results obtained within these 29 years in a series of 1800 patients with a malignant melanoma we recommend to perform the surgical treatment of a primary malignant melanoma with the use of a non-radical excision.

[Evaluation of diet in a sample of Czech mothers six months after delivery]. / Zhodnocení stravování vzorku ceských matek v sestém mesíci po porodu.

BACKGROUND: Health care of nursing mothers and their infants is an important priority of primary preventive care. The mother's diet plays an important role in this respect. The objective of the presented investigation was to assess the adequacy of the dietary intake of lactating mothers during the sixth month after delivery. METHODS AND RESULTS: Data on the education, body weight, height of the mother, dietary intake, evaluated from a three-day dietary record, were collected from 131 nursing mothers and compared with the Czech recommended dietary allowances for nursing mothers as well as with data from 265 controls, i.e. women who did no longer breastfeed their babies. From the results ensues a significantly higher calcium intake (937 mg; SD = 415, p < 0.001), vitamin B1 (1.1 mg, SD = 0.5, p < 0.001), total energy (8.7 MJ, SD = 2.6, p < 0.01), protein 75.4 g, SD = 18, p < 0.01), carbohydrates (281 g, SD = 112, p < 0.01) and riboflavin (1.3 mg, SD = 0.5, p < 0.01) in nursing women as compared with those not nursing. The nursing mothers, however, do not meet the Czech recommended dietary allowances as regards total energy, calcium, vitamin C, linoleic acid, vegetable proteins and iron. Other problematic nutrients-magnesium, zinc, folates, pyridoxine, selenium and iodine could not be assessed as they are not listed in the Czech food composition tables. In women with university education the energy and nutrient intake was in the majority more favourable than in women with elementary education. On the other hand no statistical differences were found in weight increments during the period from the beginning of gestation to the sixth month after delivery between nursing and not nursing mothers. CONCLUSIONS: The results of analysis of the dietary intake of nursing mothers indicate that the Czech recommended allowances are not met as regards energy, calcium, linoleic acid, protein and iron. Whether the intake is really inadequate or whether the recommended allowances are excessive remains an open question.

[The short-bowel syndrome]. / Syndrom krátkého streva.

This study was designed to asses the clinical course of five children with a short bowel syndrome after massive intestinal resection during neonatal period. On the basis of their experience the authors analyze some properties that may be advantageous in this syndrome and discuss the most important factors, including enteral feeding at an early postresection stage, which influence a full development of the small bowel adaptive mechanisms. They point out that so called "short gut colitis", sometimes occurring during advancement of enteral nutrition, can be successfully treated by sulphasalazine. The authors come to the conclusion that the prognosis for newborn infants undergoing an excessive bowel resection is far well thanks to enhancement of the intestinal adaptation by a combination of a long-term parenteral nutrition with enteral feeding.

MCNPX evaluation of gamma spectrometry results in high radon concentration areas.

The radon concentration in underground workplaces may reach tens of thousands of Bq m(-3). A simple MCNPXTM Monte Carlo (MC) model of a cave was developed to estimate the influence of radon on the in situ gamma spectrometry results in various geometries and radon concentrations. The detector total count rate was obtained as the sum of the individual count rates due to 214Bi in the air, radon in the walls and deposition of radon daughters on surfaces. The MC model was then modified and used in the natural conditions of the Mladec Caves, Czech Republic. The content of 226Ra was calculated from laboratory gamma spectrometry measurements, and the concentrations of unattached and attached 214Bi were measured using the FRITRA4 device (SMM-Prague). We present a comparison of the experimental results with results calculated by the MCNPXTM model of the Gamma Surveyor spectrometry probe (GF Instruments) with a 3″×3″ NaI(Tl) detector and a 2″×2″ BGO detector.

EMRP project MetroMetal: selected results of ENVINET and CMI.

Within the framework of the European Metrological Research Program (EMRP) IND04 MetroMetal 'Ionizing radiation metrology for the metallurgical industry', joint research carried out by 14 metrological institutions from countries within the European Union and the company ENVINET, questions concerning the determination of radioactivity in samples relevant to the metallurgical industry were resolved. The results of project tasks, namely questionnaire, composite standards development and samples from metallurgical industry measurement, are presented here.

Correction of the TRUE summations in volume sources.

The correction factors for volume sources may be approximated using average efficiencies determined by experiment or by Monte Carlo methods in the same way as for point sources. This simple technique does not take into account properly the absorption of photons in the source, nor the change of the effective solid angle. A more precise method must take into account for the spatial distribution of products of efficiencies η(peak)*η(total) (for summing-out) or η(peak)*η(peak) (for summing-in) over the volume of the source. The differences between the approximate and the more precise method are discussed.

Microtron MT 25 as a source of neutrons.

The objective was to describe Microtron MT25 as a source of neutrons generated by bremsstrahlung induced photonuclear reactions in U and Pb targets. Bremsstrahlung photons were produced by electrons accelerated at energy 21.6 MeV. Spectral fluence of the generated neutrons was calculated with MCNPX code and then experimentally determined at two positions by means of a Bonner spheres spectrometer in which the detector of thermal neutrons was replaced by activation Mn tablets or track detectors CR-39 with a (10)B radiator. The measured neutron spectral fluence and the calculated anisotropy served for the estimation of neutron yield from the targets and for the determination of ambient dose equivalent rate at the place of measurement. Microtron MT25 is intended as one of the sources for testing neutron sensitive devices which will be sent into the space.