scholarly journals Design and installation of a hot water layer system at the Tehran research reactor

2013 ◽  
Vol 28 (1) ◽  
pp. 18-24
Author(s):  
Sayedeh Mirmohammadi ◽  
Morteza Gharib ◽  
Parnian Ebrahimzadeh ◽  
Reza Amrollahi
Keyword(s):  
Research Reactor ◽  
Cooling Water ◽  
Fission Products ◽  
Water Layer ◽  
Partial Solution ◽  
Time Frame ◽  
Reactor Power ◽  
Hot Water ◽  
Layer System ◽  
Tehran Research Reactor

A hot water layer system (HWLS) is a novel system for reducing radioactivity under research reactor containment. This system is particularly useful in pool-type research reactors or other light water reactors with an open pool surface. The main purpose of a HWLS is to provide more protection for operators and reactor personnel against undesired doses due to the radio- activity of the primary loop. This radioactivity originates mainly from the induced radioactivity contained within the cooling water or probable minute leaks of fuel elements. More importantly, the bothersome radioactivity is progressively proportional to reactor power and, thus, the HWLS is a partial solution for mitigating such problems when power upgrading is planned. Following a series of tests and checks for different parameters, a HWLS has been built and put into operation at the Tehran research reactor in 2009. It underwent a series of comprehensive tests for a period of 6 months. Within this time-frame, it was realized that the HWLS could provide a better protection for reactor personnel against prevailing radiation under containment. The system is especially suitable in cases of abnormality, e. g. the spread of fission products due to fuel failure, because it prevents the mixing of pollutants developed deep in the pool with the upper layer and thus mitigates widespread leakage of radioactivity.

Hot-Water Layer, Heat-Loss Characteristics of an Open-Pool-Type Research Reactor for Reducing the Pool Top Radiation Level

2010 ◽  
Author(s):  
Young-Chul Park
Keyword(s):  
Heat Loss ◽  
Flow Condition ◽  
Research Reactor ◽  
Water Layer ◽  
Hot Water ◽  
Radiation Level ◽  
Downward Flow ◽  
Reactor Coolant ◽  
Reactor Pool ◽  
Pool Type

During an open-pool-type research reactor operation, it is necessary to access the pool top area for un/loading irradiation test pieces by a required irradiation period. However, when the reactor pool top radiation level exceeds the limit of radiation level by the rising of reactor chimney water contaminated by radioactivity due to a natural convection of the pool water, access the reactor pool top area is denied due to the high radiation level. In the case of HANARO, a hot-water layer (HWL, hereinafter) is maintained below a depth of 1.2 m from the top of the reactor pool in order to reduce the radiation level of the reactor pool top area. After a normal operation of the HWL, the pool top radiation level is safely maintained below the limit of the pool top radiation level. For studying more the characteristics of the HWL under a reactor coolant downward flow condition, The HWL heat loss is calculated based on the HANARO HWL calculation model. The HWL heat loss characteristics were reviewed by variations of the HWL temperature, reactor core coolant flow direction, and reactor power. It was confirmed through the results that the HWL heat loss under a reactor coolant downward flow condition was increased by about 20% to 60% over that under a reactor coolant upward flow condition, as per the HWL temperature variation. It was the reason that the HWL bottom convection heat loss was increased by the higher flow rate under a reactor coolant downward flow condition than that under a reactor coolant in an upward flow condition.

Determination of Tehran Research Reactor power by 16N gamma detection

2011 ◽  
Vol 38 (12) ◽  
pp. 2667-2672 ◽  
Author(s):  
Hamid Reza Armozd ◽  
Morteza Gharib ◽  
Hossein Afarideh ◽  
Mitra Ghergherehchi ◽  
Azim Ahmadi Niar ◽  
...  
Keyword(s):  
Research Reactor ◽  
Reactor Power ◽  
Tehran Research Reactor ◽  
Gamma Detection

Design of a Discharge Header and a Working Platform for a Research Reactor With a CFD Model

2013 ◽  
Author(s):  
Kyoungwoo Seo ◽  
Hyungi Yoon ◽  
Dae-young Chi ◽  
Seonghoon Kim ◽  
Juhyeon Yoon
Keyword(s):  
Research Reactor ◽  
Cold Water ◽  
Cooling System ◽  
Reactor Core ◽  
Water Layer ◽  
Hot Water ◽  
Primary Coolant ◽  
Radiation Level ◽  
Reactor Pool ◽  
Pool Type

Most research reactors are designed as an open-pool type and the reactor is located on the bottom of the open-pool. The reactor in the pool is connected to the primary cooling system, which is designed for adequate cooling of the heat generated from the reactor core. One of the characteristics of an open-pool type research reactor is that the primary coolant after passing through the reactor core and the primary cooling system (PCS) is returned to the reactor pool. Because the primary coolant contains many kinds of radionuclides, the research reactor should be designed to protect the radionuclides from being released outside the pool by a stratified stable water layer, which is formed between a hot water layer and cold water near the reactor and prevents the natural circulation of water in the pool. In this study, additional components such as a discharge header and a working platform inside the pool were developed to help diminish the radiation level to the pool top. To discharge coolant stably inside the reactor pool, a discharge header was installed at the end of the pool inlet pipe. Many holes were made in the discharge header to discharge the coolant slowly and minimize the disturbance of the hot water layer by the flow inside the pool. The working platform was also equipped inside the reactor pool to remove the convective flow near the pool top. The commercially available CFD code, ANSYS CFD-FLEUNT, was used to specifically design the discharge header and working platform for satisfying the requirement of the pool top radiation level. The computations were conducted to analyze the flow and temperature characteristics inside the pool for several geometries using an SST k-ω turbulent model and cell modeling, which were conducted to isolate the root cause of these differences and the given inlet conditions. The discharge header and working platform were designed using the CFD results.

Calculation and Measurement of Kinetics Parameters of Tehran Research Reactor

2009 ◽  
Author(s):  
Seyed Abolfazl Hosseini ◽  
Naser Vosoughi ◽  
Mortaza Gharib ◽  
Mohammad Bagher Ghofrani
Keyword(s):  
Research Reactor ◽  
Reactor Power ◽  
Coolant Temperature ◽  
Neutron Generation ◽  
Reactor Physics ◽  
Kinetics Parameters ◽  
Second Stage ◽  
Cold State ◽  
Tehran Research Reactor ◽  
Relative Errors

Effective delayed neutron fraction βeff and neutron generation time Λ are important factors in reactor physics calculation and transient analysis. In first stage of this research, these kinetics parameters have been calculated for two states of Tehran research reactor (TRR), i.e. cold (fuel, clad and coolant temperature 20°C) and hot (fuel, clad and coolant temperature 65, 49 and 44°C, respectively) using MTR_PC code. In second stage, these parameters have been measured with experimental method based on Inhour equation. For cold state, calculated βeff and Λ by MTR_PC are 0.008315 and 30.190 μsec, respectively. Same parameters in hot state are 0.008303 and 33.828 μsec, respectively. The measured βeff and Λ for cold state (reactor power is range of 100–200 Watt) are 0.008088 and 32.001 μsec, respectively. The calculated and measured values are in good agreement. Relative errors are % 2.8 for βeff and % 5.6 for Λ which are smaller than the other reported results.

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