Model of a Dry Storage Facility for a Medium Nuclear Power Plant

Author(s):  
Mile Bace ◽  
Kresimir Trontl ◽  
Dubravko Pevec

Abstract The intention was to model a dry storage facility that could satisfy the needs of a medium nuclear power plant similar to the NPP Krsko. The attention has been focused on radiation dose rate analyses and criticality calculations. Using the SCALE 4.4 code package and modified QAD-CGGP code, we modeled a facility that satisfies the basic criteria for public radiation protection. The capacity of the storage is 1,400 spent fuel assemblies which is adequate for a forty years medium NPP lifetime.

Author(s):  
Davor Grgic ◽  
Mario Matijevic ◽  
Paulina Duckic ◽  
Radomir Jecmenica

Abstract In this paper shielding analysis was performed to determine neutron and gamma dose rates around the transfer cask HI-TRAC VW loaded with Spent Fuel Assemblies (SFA) from Nuclear Power Plant (NPP) Krsko Spent Fuel Dry Storage (SFDS) Campaign one. The HI-TRAC VW is a multi-layered cylindrical vessel designed to accept a Multi Purpose Canister (MPC) during loading, unloading and transfer to dry storage building. The MPC can contain up to 37 spent fuel assemblies. The analysis was divided into two steps. The first step was the source term generation using ORIGEN-S module of the SCALE code package. The source was calculated based on the operating history of spent fuel assemblies currently located in the NPP Krsko spent fuel pool. The obtained particle intensities and source spectra of the SFA were used in the second step to calculate the dose rates around the transfer cask. A comprehensive hybrid shielding analysis included the calculation of dose rates resulting from fuel neutrons and gammas, neutron induced gammas (n-g reaction), and hardware activation gammas under normal conditions and during accident scenario. To obtain the dose rates within the acceptable uncertainties, FW-CADIS variance reduction scheme, as implemented in ADVANTG code, was adopted for accelerating final MCNP6 calculations. The dose rates around HI-TRAC VW cask were calculated using MCNP6 code for all 16 casks loading belonging to Campaign one in order to illustrate the impact of fuel assembly selection schemes proposed by company responsible for project realization (Holtec International).


Author(s):  
Nieves Marti´n ◽  
Manuel Rodri´guez

ENRESA is the National Spanish Agency responsible of the dismantling of Nuclear Facilities, previous Transfer of ownership of the facility from the Utility to ENRESA. On April 30th 2006, Jose´ Cabrera Nuclear Power Plant (Fig. 1) was definitively shutdown, and two years later, on April 30th 2008, ENRESA requested the transfer of the ownership of the Plant from the Ministry along with the corresponding authorization for performance of the Dismantling and Decommissioning Plan. On February 1st 2010, ENRESA was authorized to initiate the dismantling of Jose´ Cabrera NPP, once the spent fuel has been stored on-site at a dry storage facility (ISFSI). Currently, preparatory activities are underway, including the modification of systems and auxiliary facilities for waste and material management. Main challenges of the project include the removal of major components (vessel, steam generator, pressurizer, main pump and primary loop), and the use of large containers (CE-2b) to reduce segmentation of activated parts.


2019 ◽  
Vol 24 (1) ◽  
pp. 64-70
Author(s):  
Mingliang Xie ◽  
Fei Xie ◽  
Fuchang Shan ◽  
Zhengquan Xie ◽  
Mingrui Li ◽  
...  

2013 ◽  
Vol 1518 ◽  
pp. 277-282 ◽  
Author(s):  
Haruo SATO ◽  
Tadafumi NIIZATO ◽  
Kenji AMANO ◽  
Shingo TANAKA ◽  
Kazuhiro AOKI

ABSTRACTThe accident of the TEPCO Fukushima Dai-ichi Nuclear Power Plant occurred by the 2011 off the Pacific coast of Tohoku Earthquake on 11 Mar. 2011. It is estimated that totally 1.2-1.5x1016 Bq for 137Cs and 1.5-1.6x1017 Bq for 131I were released until the beginning of Apr. and those radionuclides (RN) were deposited on soil surface and forest etc. widely around Fukushima Pref. This work was carried out as one of the investigations for making the distribution maps of radiation dose rate and soil contaminated by RNs which the MEXT promotes. The Geoslicer investigation on the depth distribution of RNs in soil was performed after 3 months from the accident. The investigation was conducted at 11 locations in Nihonmatsu City, Kawamata Town and Namie Town, and soil samples of depth 50 cm to 1 m were taken. Both of 134Cs and 137Cs were detected in all investigated locations, and 129mTe and 110mAg were detected only in locations where radiation dose rates are high. At many locations investigated, radiocaesium more than 99 % distributed within a depth of 10 cm in soil in the surface layer. On the other hand, RNs tended to distribute to deeper part in soil at locations that are supposed to have been used as farmland than in soil in the surface layer, and radiocaesium more than 99 % in soil at locations that are supposed to have been used as farmland also distributed within a depth of around 14 cm. The apparent diffusion coefficients (Da) of RNs derived from penetration profiles near the surface layer showed a tendency to be higher in soil at locations that are supposed to have been used as farmland (Da=0.1-1.5x10-10 m2/s) than in soil in the surface layer (Da=0.65-4.4x10-11 m2/s), and most Da-values were nearly 10-11 m2/s. The distribution coefficients (Kd) by a batch method were in the range of Kd=2,000-61,000 ml/g for Cs and Kd=0.5-140 ml/g for I. Although the Kd-values are different between cation (Cs+) and anion (I-), the Da-values (134Cs, 137Cs, 129mTe and 110mAg) were similar levels. This is considered to be due to that the Da-values were controlled by dispersion by flow of rain water.


2014 ◽  
Vol 111 (10) ◽  
pp. E914-E923 ◽  
Author(s):  
Kouji H. Harada ◽  
Tamon Niisoe ◽  
Mie Imanaka ◽  
Tomoyuki Takahashi ◽  
Katsumi Amako ◽  
...  

Radiation dose rates were evaluated in three areas neighboring a restricted area within a 20- to 50-km radius of the Fukushima Daiichi Nuclear Power Plant in August–September 2012 and projected to 2022 and 2062. Study participants wore personal dosimeters measuring external dose equivalents, almost entirely from deposited radionuclides (groundshine). External dose rate equivalents owing to the accident averaged 1.03, 2.75, and 1.66 mSv/y in the village of Kawauchi, the Tamano area of Soma, and the Haramachi area of Minamisoma, respectively. Internal dose rates estimated from dietary intake of radiocesium averaged 0.0058, 0.019, and 0.0088 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. Dose rates from inhalation of resuspended radiocesium were lower than 0.001 mSv/y. In 2012, the average annual doses from radiocesium were close to the average background radiation exposure (2 mSv/y) in Japan. Accounting only for the physical decay of radiocesium, mean annual dose rates in 2022 were estimated as 0.31, 0.87, and 0.53 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. The simple and conservative estimates are comparable with variations in the background dose, and unlikely to exceed the ordinary permissible dose rate (1 mSv/y) for the majority of the Fukushima population. Health risk assessment indicates that post-2012 doses will increase lifetime solid cancer, leukemia, and breast cancer incidences by 1.06%, 0.03% and 0.28% respectively, in Tamano. This assessment was derived from short-term observation with uncertainties and did not evaluate the first-year dose and radioiodine exposure. Nevertheless, this estimate provides perspective on the long-term radiation exposure levels in the three regions.


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