Geri Dön

Kolemanitli betonların nötron zırhlama etkinliğinin ve aktivitesinin incelenmesi

The İnvestigation of neutron shielding efficiencyand radiactivity of the concretes containing colemanite

  1. Tez No: 35713
  2. Yazar: YASEMİN YARAR
  3. Danışmanlar: PROF. DR. AHMET BAYÜLKEN
  4. Tez Türü: Doktora
  5. Konular: Nükleer Mühendislik, Nuclear Engineering
  6. Anahtar Kelimeler: Belirtilmemiş.
  7. Yıl: 1994
  8. Dil: Türkçe
  9. Üniversite: İstanbul Teknik Üniversitesi
  10. Enstitü: Nükleer Bilimler Enstitüsü
  11. Ana Bilim Dalı: Belirtilmemiş.
  12. Bilim Dalı: Belirtilmemiş.
  13. Sayfa Sayısı: 178

Özet

code, ANITA, with the GREAC-ECN-5 cross section library for different neutron flux and irradiation conditions. The activity, dose and decay heat of concrete shields subject to hypothetical ly 20 years of stepwise and continuous irradiation are calculated. The decay of radio-isotopes for 10s years after shutdown were studied. At the end of the first irradiation step, colemanite concrete reaches saturation activity. It means, radioactive inventory of colemanite concrete are mostly composed of short-lived nuclei. At shutdown, the total activity of ordinary and colemanite concretes are almost the same. Predominant radio isotopes are A 1-28, N-16 and Aî - 37. These nuclei are due to some common elements found in concrete and colemanite has no great effect. If the shutdown radioactive inventory of both shields are compared, it is observed that the activities induced by common elements are very near to each other, but H-3, He-6, Li-8, Be-8, Be-10, Be-11. B-12 activities are increased in colemanite concrete. These nuclei are. directly or indirectly, imposed by boron reactions. Among them, only H3 seems to be important here because of its relatively long half-life and contribution to the activity.. Because of colemanite addition, mainly H,0,Ca nuclei are increased in concrete. Trace element composition of colemanite concrete is only 0.066 % by weight. The main difference between concrete compositions is 1.255 % of bor content of colemanite concrete. If the boron-neutron reactions are examined, it is observed that most of the reaction products are stable and the active ones have very small half-lives and immediately decay after shutdown. They have no decay gammas, thus not weighting the gamma dose problem. The decay characteristics of the total activity of concretes are different from each other. The difference is maximum around 10 years after shutdown. This is due to H-3 radio-isotopes. H-3 activity of colemanite concrete at shutdown is 11.3 times greater than ordinary concrete. Its half-live is 12.3 years and it is effective for 100 years («10 half-lives). After that time, both concretes have approximately the same activity. The most important reactions giving H-3 are caused by Li-6 and Li-7. Before irradiation, Li isotopes are not available in concrete composition and come out with xoB(n,na)sLi, 1°B(n,a),'Li reactions. The latter reaction's cross section with thermal neutron is very high. Thus, boron nuclei help indirectly to increase H-3 activity in colemanite concrete. XII

Özet (Çeviri)

From the decommissioning point of view, colemanite concrete can be classified as high-level active waste at shutdown. Since, the most of the nuclei contributing to the shutdown activity of colemanite concrete are short-lived, it loses its activity very fast. 1 day after shutdown, 78.3 % of its activity decreases. 30 days after, 87.2 % and 1 year after, 97.2 % of its activity is decreased. Depending on the neutron flux level, 1-10 years after shutdown, colemanite concrete can be handled as middle- level active waste. 10s years later, it can be taken as low-level active waste. Gamma dose in colemanite concrete is lower than ordinary concrete. Although thermal neutron absorption increases due to the boron content of colemanite, secondary gamma ray generation does not aggravate. The most of the reaction products are stable. The active ones usually emit soft gammas attenuated in the shield. Colemanite concrete was compared two different concrete shields from the literature, containing colemanite and/or barite aggregates, under the same conditions. It is found that the shield thickness of colemanite-barite concrete must be ** 2 cm, that of barite concrete =» 17 cm more than colemanite concrete shield thickness. Among them, except ordinary Portland concrete, colemanite concrete has less shield volume, mass and cost. If the activities of these concretes are compared. It is observed that they are 2.7- 2.9 times more active than colemanite concrete at shutdown and reach its activity 20-50 years after shutdown. Consequently, by adding 10 wt. % of colemanite to high quality Portland concrete, thinner shields can be constructed. This material saving at the beginning of shield design is more important from the radioactive waste management point of view. Thinner shield means that less amount of radioactive waste will be handled and stored for final disposal. Thus, supplying economy in decommissioning cost. Colemanite addition does not aggravate the total activity of ordinary Portland concrete. The difference appears during the decay period because of H-3 activity. 100 years after shutdown, both concretes have the same activity. On the other and, colemanite content in concrete does not improve secondary gamma-ray and H gas production. These are also important for safety operation condition. Xlllcode, ANITA, with the GREAC-ECN-5 cross section library for different neutron flux and irradiation conditions. The activity, dose and decay heat of concrete shields subject to hypothetical ly 20 years of stepwise and continuous irradiation are calculated. The decay of radio-isotopes for 10s years after shutdown were studied. At the end of the first irradiation step, colemanite concrete reaches saturation activity. It means, radioactive inventory of colemanite concrete are mostly composed of short-lived nuclei. At shutdown, the total activity of ordinary and colemanite concretes are almost the same. Predominant radio isotopes are A 1-28, N-16 and Aî - 37. These nuclei are due to some common elements found in concrete and colemanite has no great effect. If the shutdown radioactive inventory of both shields are compared, it is observed that the activities induced by common elements are very near to each other, but H-3, He-6, Li-8, Be-8, Be-10, Be-11. B-12 activities are increased in colemanite concrete. These nuclei are. directly or indirectly, imposed by boron reactions. Among them, only H3 seems to be important here because of its relatively long half-life and contribution to the activity.. Because of colemanite addition, mainly H,0,Ca nuclei are increased in concrete. Trace element composition of colemanite concrete is only 0.066 % by weight. The main difference between concrete compositions is 1.255 % of bor content of colemanite concrete. If the boron-neutron reactions are examined, it is observed that most of the reaction products are stable and the active ones have very small half-lives and immediately decay after shutdown. They have no decay gammas, thus not weighting the gamma dose problem. The decay characteristics of the total activity of concretes are different from each other. The difference is maximum around 10 years after shutdown. This is due to H-3 radio-isotopes. H-3 activity of colemanite concrete at shutdown is 11.3 times greater than ordinary concrete. Its half-live is 12.3 years and it is effective for 100 years («10 half-lives). After that time, both concretes have approximately the same activity. The most important reactions giving H-3 are caused by Li-6 and Li-7. Before irradiation, Li isotopes are not available in concrete composition and come out with xoB(n,na)sLi, 1°B(n,a),'Li reactions. The latter reaction's cross section with thermal neutron is very high. Thus, boron nuclei help indirectly to increase H-3 activity in colemanite concrete. XIIFrom the decommissioning point of view, colemanite concrete can be classified as high-level active waste at shutdown. Since, the most of the nuclei contributing to the shutdown activity of colemanite concrete are short-lived, it loses its activity very fast. 1 day after shutdown, 78.3 % of its activity decreases. 30 days after, 87.2 % and 1 year after, 97.2 % of its activity is decreased. Depending on the neutron flux level, 1-10 years after shutdown, colemanite concrete can be handled as middle- level active waste. 10s years later, it can be taken as low-level active waste. Gamma dose in colemanite concrete is lower than ordinary concrete. Although thermal neutron absorption increases due to the boron content of colemanite, secondary gamma ray generation does not aggravate. The most of the reaction products are stable. The active ones usually emit soft gammas attenuated in the shield. Colemanite concrete was compared two different concrete shields from the literature, containing colemanite and/or barite aggregates, under the same conditions. It is found that the shield thickness of colemanite-barite concrete must be ** 2 cm, that of barite concrete =» 17 cm more than colemanite concrete shield thickness. Among them, except ordinary Portland concrete, colemanite concrete has less shield volume, mass and cost. If the activities of these concretes are compared. It is observed that they are 2.7- 2.9 times more active than colemanite concrete at shutdown and reach its activity 20-50 years after shutdown. Consequently, by adding 10 wt. % of colemanite to high quality Portland concrete, thinner shields can be constructed. This material saving at the beginning of shield design is more important from the radioactive waste management point of view. Thinner shield means that less amount of radioactive waste will be handled and stored for final disposal. Thus, supplying economy in decommissioning cost. Colemanite addition does not aggravate the total activity of ordinary Portland concrete. The difference appears during the decay period because of H-3 activity. 100 years after shutdown, both concretes have the same activity. On the other and, colemanite content in concrete does not improve secondary gamma-ray and H gas production. These are also important for safety operation condition. Xlllcode, ANITA, with the GREAC-ECN-5 cross section library for different neutron flux and irradiation conditions. The activity, dose and decay heat of concrete shields subject to hypothetical ly 20 years of stepwise and continuous irradiation are calculated. The decay of radio-isotopes for 10s years after shutdown were studied. At the end of the first irradiation step, colemanite concrete reaches saturation activity. It means, radioactive inventory of colemanite concrete are mostly composed of short-lived nuclei. At shutdown, the total activity of ordinary and colemanite concretes are almost the same. Predominant radio isotopes are A 1-28, N-16 and Aî - 37. These nuclei are due to some common elements found in concrete and colemanite has no great effect. If the shutdown radioactive inventory of both shields are compared, it is observed that the activities induced by common elements are very near to each other, but H-3, He-6, Li-8, Be-8, Be-10, Be-11. B-12 activities are increased in colemanite concrete. These nuclei are. directly or indirectly, imposed by boron reactions. Among them, only H3 seems to be important here because of its relatively long half-life and contribution to the activity.. Because of colemanite addition, mainly H,0,Ca nuclei are increased in concrete. Trace element composition of colemanite concrete is only 0.066 % by weight. The main difference between concrete compositions is 1.255 % of bor content of colemanite concrete. If the boron-neutron reactions are examined, it is observed that most of the reaction products are stable and the active ones have very small half-lives and immediately decay after shutdown. They have no decay gammas, thus not weighting the gamma dose problem. The decay characteristics of the total activity of concretes are different from each other. The difference is maximum around 10 years after shutdown. This is due to H-3 radio-isotopes. H-3 activity of colemanite concrete at shutdown is 11.3 times greater than ordinary concrete. Its half-live is 12.3 years and it is effective for 100 years («10 half-lives). After that time, both concretes have approximately the same activity. The most important reactions giving H-3 are caused by Li-6 and Li-7. Before irradiation, Li isotopes are not available in concrete composition and come out with xoB(n,na)sLi, 1°B(n,a),'Li reactions. The latter reaction's cross section with thermal neutron is very high. Thus, boron nuclei help indirectly to increase H-3 activity in colemanite concrete. XIIFrom the decommissioning point of view, colemanite concrete can be classified as high-level active waste at shutdown. Since, the most of the nuclei contributing to the shutdown activity of colemanite concrete are short-lived, it loses its activity very fast. 1 day after shutdown, 78.3 % of its activity decreases. 30 days after, 87.2 % and 1 year after, 97.2 % of its activity is decreased. Depending on the neutron flux level, 1-10 years after shutdown, colemanite concrete can be handled as middle- level active waste. 10s years later, it can be taken as low-level active waste. Gamma dose in colemanite concrete is lower than ordinary concrete. Although thermal neutron absorption increases due to the boron content of colemanite, secondary gamma ray generation does not aggravate. The most of the reaction products are stable. The active ones usually emit soft gammas attenuated in the shield. Colemanite concrete was compared two different concrete shields from the literature, containing colemanite and/or barite aggregates, under the same conditions. It is found that the shield thickness of colemanite-barite concrete must be ** 2 cm, that of barite concrete =» 17 cm more than colemanite concrete shield thickness. Among them, except ordinary Portland concrete, colemanite concrete has less shield volume, mass and cost. If the activities of these concretes are compared. It is observed that they are 2.7- 2.9 times more active than colemanite concrete at shutdown and reach its activity 20-50 years after shutdown. Consequently, by adding 10 wt. % of colemanite to high quality Portland concrete, thinner shields can be constructed. This material saving at the beginning of shield design is more important from the radioactive waste management point of view. Thinner shield means that less amount of radioactive waste will be handled and stored for final disposal. Thus, supplying economy in decommissioning cost. Colemanite addition does not aggravate the total activity of ordinary Portland concrete. The difference appears during the decay period because of H-3 activity. 100 years after shutdown, both concretes have the same activity. On the other and, colemanite content in concrete does not improve secondary gamma-ray and H gas production. These are also important for safety operation condition. Xlll

Benzer Tezler

  1. Tez No

    234187

    Hamile ratlarda oksidatif strese neden olan radyasyona karşı kolemanitli betonun koruyucu etkisinin araştırılması

    An investigation of protective effect of concrete with colemanite on the radiation-induced oxidative stress in pregnant rats

    OSMAN GENÇEL

    Doktora

    Türkçe

    Türkçe

    2009

    İnşaat MühendisliğiSüleyman Demirel Üniversitesi

    İnşaat Mühendisliği Ana Bilim Dalı

    PROF. DR. MUSTAFA NAZIROĞLU

    PROF. DR. MÜMİN FİLİZ

  2. Tez No

    244763

    Bor ve barit agregalı ağır betonların nötron parçacıkları, x- ve ?-ışınları radyasyon soğurganlıklarının belirlenmesi

    Determined of radiation absorbtion for neutron particles, x- and ?-rays of heavy concretes included bore and barite aggregates

    FARUK DEMİR

    Doktora

    Türkçe

    Türkçe

    2009

    Fizik ve Fizik MühendisliğiAtatürk Üniversitesi

    Fizik Ana Bilim Dalı

    PROF. DR. GÖKHAN BUDAK

  3. Tez No

    682523

    Kolemanit kullanılarak üretilen alkali aktive harçların nötron soğurma özelliklerine yüksek sıcaklığın etkisi

    The effect of high temperature on the neutron attenuation propertiesof alkali-activated mortars produced by usingcolemanite

    MUHAMMET SAMİ TÜRETKEN

    Yüksek Lisans

    Türkçe

    Türkçe

    2021

    İnşaat MühendisliğiBayburt Üniversitesi

    İnşaat Mühendisliği Ana Bilim Dalı

    DOÇ. DR. HACI SÜLEYMAN GÖKÇE

  4. Tez No

    353466

    Bor katkılı özellikli beton üretimi

    Specified concrete production containing boron

    HAKAN SARIKAYA

    Doktora

    Türkçe

    Türkçe

    2014

    Mühendislik BilimleriSüleyman Demirel Üniversitesi

    Maden Mühendisliği Ana Bilim Dalı

    PROF. DR. RAŞİT ALTINDAĞ

  5. Tez No

    307646

    Bor kaplı hafif agregalı betonların fiziksel ve kimyasal özelliklerinin araştırılması

    Investigation of the physical and chemical properties of boron-coated ligthweigth aggregate concrete

    ÖZLEM SALLI BİDECİ

    Doktora

    Türkçe

    Türkçe

    2013

    MimarlıkTrakya Üniversitesi

    Mimarlık Bölümü

    PROF. DR. SABİT OYMAEL

Geri Dön