Quantification of in-containment fission products source term for 1000MWe PWR under loss of coolant accident

Mehboob, Khurram,Park, Kwangheon,Khan, Rehan Elsevier 2015 Annals of nuclear energy Vol.75 No.-

<P><B>Abstract</B></P> <P>The aim of this work is the modeling and simulation of in-containment fission products (FPs) quantification and behavior under loss of coolant accident (LOCA) in terms of NUREG-1465 key aspects. For this purpose, a kinetic model has been developed to determine the quantification and behavior of in-containment source term after loss of coolant accident for typical 1000MWe PWR. A more realistic approach of continuous release of fission products from damaged core has been implemented with coolant retention. The simulation for in-containment fission product quantification influenced by containment atmosphere and containment system response has been carried out. Dramatic results have been obtained upon comparison study of fission product behaviors with different computational values. Moreover a contradiction in mixing rate (<I>w<SUB>x</SUB> </I>) value has been observed with a factor of 10 in comparison with Saeed et al. (2012).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Kinetic modeling for in-containment fission product activity. </LI> <LI> Modeling and simulation of in-containment source term after LOCA. </LI> <LI> Quantification of airborne in-containment activity. </LI> <LI> BURNUP activity calculation and comparison with literature. </LI> <LI> Study the effect of ESFs and coolant retention with mixing rate. </LI> </UL> </P>

Analysis of activated colloidal crud in advanced and modular reactor under pump coastdown with kinetic corrosion

Mehboob Khurram,Al-Zahrani Yahya A. 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.12

The analysis of rapid flow transients in Reactor Coolant Pumps (RCP) is essential for a reactor safety study. An accurate and precise analysis of the RCP coastdown is necessary for the reactor design. The coastdown of RCP affects the coolant temperature and the colloidal crud in the primary coolant. A realistic and kinetic model has been used to investigate the behavior of activated colloidal crud in the primary coolant and steam generator that solves the pump speed analytically. The analytic solution of the non-dimensional flow rate has been determined by the energy ratio b. The kinetic energy of the coolant fluid and the kinetic energy stored in the rotating parts of a pump are two essential parameters in the form of b. Under normal operation, the pump's speed and moment of inertia are constant. However, in a coastdown situation, kinetic damping in the interval has been implemented. A dynamic model ACCP-SMART has been developed for System Integrated Modular and Advanced Reactor (SMART) to investigate the corrosion due to activated colloidal crud. The Fickian diffusion model has been implemented as the reference corrosion model for the constituent component of the primary loop of the SMART reactor. The activated colloidal crud activity in the primary coolant and steam generator of the SMART reactor has been studied for different equilibrium corrosion rates, linear increase in corrosion rate, and dynamic RCP coastdown situation energy ratio b. The coolant specific activity of SMART reactor equilibrium corrosion (4.0 mg s1 ) has been found 9.63 103 mCi cm3 , 3.53 103 mC cm3 , 2.39 102 mC cm3 , 8.10 103 mC cm3 , 6.77 103 mC cm3 , 4.95 104 mC cm3 , 1.19 103 mC cm3 , and 7.87 104 mC cm3 for 24Na, 54Mn, 56Mn, 59Fe, 58Co, 60Co, 99Mo, and 51Cr which are 14.95%, 5.48%, 37.08%, 12.57%, 10.51%, 0.77%, 18.50%, and 0.12% respectively. For linear and exponential coastdown with a constant corrosion rate, the total coolant and steam generator activity approaches a higher saturation value than the normal values. The coolant and steam generator activity changes considerably with kinetic corrosion rate, equilibrium corrosion, growth of corrosion rate (DC/Dt), and RCP coastdown situations. The effect of the RCP coastdown on the specific activity of the steam generators is smeared by linearly rising corrosion rates, equilibrium corrosion, and rapid coasting down of the RCP. However, the time taken to reach the saturation activity is also influenced by the slope of corrosion rate, coastdown situation, equilibrium corrosion rate, and energy ratio b.

Radionuclide concentrations in agricultural soil and lifetime cancer risk due to gamma radioactivity in district Swabi, KPK, Pakistan

Azeem Umair,Younis Hannan,ullah Niamat,Mehboob Khurram,Ajaz Muhammad,Ali Mushtaq,Hidayat Abdullah,Muhammad Wazir 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1

This study focuses on measuring the levels of naturally occurring radioactivity in the soil of Swabi, Khyber Pakhtunkhwa, Pakistan, as well as the associated health hazard. Thirty (30) soil samples were collected from various locations and analyzed for 226Ra, 232Th, and 40K radioactivity levels using a High Purity Germanium detector (HPGe) gamma-ray spectrometer with a photo-peak efficiency of approximately 52.3%. The average values obtained for these radionuclides are 35.6 ± 5.7 Bqkg 1, 47 ± 12.5 Bqkg 1, and 877 ± 153 Bqkg 1, respectively. The level of 232Th is slightly higher and 40K is 2.2 times higher than the internationally recommended limit of 30 Bqkg 1 and 400 Bqkg 1, respectively. Various parameters were calculated based on the results obtained, including Radium Equivalent (Raeq), External Hazard (Hex), Absorbed Dose Rate (D), Annual Gonadal Equivalent Dose (AGDE), Annual Effective Dose Rate, and Excess Lifetime Cancer Risk (ELCR), which are 170.3 ± 24 Bqkg 1, 0.46 ± 0.06 Bqkg 1, 81.4 ± 2.04 nGy h 1, 582 ± 78.08 μSvy 1, 99.8 ± 13.5 μSv Gy 1, and 0.349 ± 0.04, respectively. These values are below the limits recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in 2002. This study highlights the potential radiation threats associated with natural radioactivity levels in the soil of Swabi and provides valuable information for public health and safety

IODINE REMOVAL EFFICIENCY IN NON-SUBMERGED AND SUBMERGED SELF-PRIMING VENTURI SCRUBBER

Ali, Majid,Yan, Changqi,Sun, Zhongning,Gu, Haifeng,Wang, Junlong,Khurram, Mehboob Korean Nuclear Society 2013 Nuclear Engineering and Technology Vol.45 No.2

The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH) and sodium thiosulphate ($Na2S_2O_3$) in water to remove the gaseous iodine ($I_2$) from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine for submerged and non-submerged operating conditions. In the non-submerged venturi scrubber, only the droplets take part in iodine removal efficiency. However, in a submerged venturi scrubber condition, the iodine gas is absorbed from gas to droplets inside the venturi scrubber and from bubbles to surrounding liquid at the outlet of a venturi scrubber. Experimentally, it is observed that the iodine removal efficiency is greater in the submerged venturi scrubber as compare to a non-submerged venturi scrubber condition. The highest iodine removal efficiency of $0.99{\pm}0.001$ has been achieved in a submerged self-priming venturi scrubber condition. A mathematical correlation is used to predict the theoretical iodine removal efficiency in submerged and non-submerged conditions, and it is compared against the experimental results. The Wilkinson et al. correlation is used to predict the bubble diameter theoretically whereas the Nukiyama and Tanasawa correlation is used for droplet diameter. The mass transfer coefficient for the gas phase is calculated from the Steinberger and Treybal correlation. The calculated results for a submerged venturi scrubber agree well with experimental results but underpredicts in the case of the non-submerged venturi scrubber.

Radiometric examination of fertilizers and assessment of their health hazards, commonly used in Pakistan

Hannan Younis,Sumbilah Shafique,Zahida Ehsan,Aleena Ishfaq,Khurram Mehboob,Muhammad Ajaz,Abdullah Hidayat,Wazir Muhammad Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.7

The radioactivity concentrations of Naturally Occurring Radioactive Materials (NORM) i.e., ²²⁶Ra, ²³²Th, and ⁴K in various chemical fertilizers being used in the agricultural soil of Pakistan were determined utilizing gamma spectrometry by employing a High Purity Germanium (HPGe) detector. The radioactivity concentrations of ²²⁶Ra, ²³²Th, and ⁴K extended from 2.58 ± 0.8-265.7 ± 8.8 Bq kg^-1, 1.53 ± 0.14-76.6 ± 1.07 Bq kg^-1 and 36.5 ± 1.34-15606.7 ± 30.2 Bq kg^-1 respectively. The radiological hazard parameters such as internal and external indices and annual effective dose rates were calculated, while excessive lifetime cancer risk factors for the indoor and outdoor areas were found in the range from 0.3×10^-3 to 10.723×10^-3 and 0.03×10^-3 to 2.7948×10^-3 of most fertilizers, however, some values were slightly higher than the UNSCEAR (The United Nations Scientific Committee on the Effects of Atomic Radiation) recommended values for potash-containing fertilizers such as MOP (Muriate of Potash).