scholarly journals Neutron Activation of Structural Materials of a Dry Storage System for Spent Nuclear Fuel and Implications for Radioactive Waste Management

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5325
Author(s):  
Se Geun Lee ◽  
Jae Hak Cheong

In order to estimate the radiological characteristics of disused dry storage systems for spent nuclear fuel, a stepwise framework to calculate neutron sources (ORIGEN-ARP), incident neutron flux and reaction rate (MCNPX), effective cross-section (hand calculation), and residual activity (ORIGEN-2) was established. Applicability of the framework was demonstrated by comparing the residual activity of a commercialized storage system, HI-STORM 100, listed in the safety analysis report and calculated in this study. For a reference case assuming an impurity-free storage system, the modified effective cross-sections were theoretically interpreted and the need for managing disused components as a radioactive waste for at least four years was demonstrated. Sensitivity analyses showed that the higher burnup induces the higher residual radioactivity, and the impurity 59Co may extend the minimum decay-in-storage period up to 51 years within the reported range of 59Co content in stainless steel. The extended long-term storage over 100 years, however, caused no significant increase in residual radioactivity. Impurity control together with appropriate decay-in-storage was proposed as an effective approach to minimize the secondary radioactive waste arising from disused dry storage systems. The results of this study could be used to optimize the decommissioning and waste management plan regarding interim storage of spent fuel.

Author(s):  
J A Richardson

Commercial reactor nuclear power generation in the United States is produced by 107 units and, during 1996, represented over 21 per cent of the nation's electricity generation in 34 of the 50 states and, through electric power wheeling, between states in most of the 48 contiguous states. Spent fuel is stored in fuel pools at 70 sites around the country and the projected rate of spent fuel production indicates that the current pool storage will be exceeded in the out years of 2000, 2010 and 2020 at 40, 67 and 69 of these sites respectively. The total accumulation projected by the end of 1996 at reactor sites is 33 700 metric tons of heavy metal (MTHM), with projections for increasing accumulations at annual rates of between 1800 and 2000 to produce an end of life for all commercial nuclear reactors of about 86 000 MTHM. There are presently eight facilities in six states with out-of-pool dry storage amounting to 1010 MTHM and this dry storage demand will increase. Based on all current commercial reactors achieving their 40 year licensed operation lifetimes, the dry storage needs will increase to 3128 MTHM at 28 sites and 20 states by 2000 and 11 307 MTHM at 58 sites in 32 states by 2010; the year 2010 is the present scheduled operation date for the federal mined geological disposal repository being characterized by the USDOE at Yucca Mountain, Nevada. The enabling statute for the federal high-level radioactive waste management programme is the 1982 Nuclear Waste Policy Act (NWPA) which charges the USDOE with the responsibility for the disposal of HLW and spent nuclear fuel. The Act also charges the utilities with the responsibility for managing their spent nuclear fuel until the USDOE can accept it into the federal waste management system. The funding for the federal programme is also stipulated by the Act with the creation of the Nuclear Waste Fund, through which the electric utilities entered into contract with the USDOE by payment of a fee of 1 mill per kilowatt hour sold and for which the USDOE would start collection of spent fuel from the reactor sites starting 31 January 1998.


2021 ◽  
Author(s):  
Ryan M. Meyer ◽  
Jeremy Renshaw ◽  
Jamie Beard ◽  
Jon Tatman ◽  
Matt Keene ◽  
...  

Abstract This paper describes development and demonstration of remote crawling systems to support periodic examinations of interim dry storage system (DSS) canisters for spent nuclear fuel in the USA. Specifically, this work relates to robotic crawler developments for “canister” based DSS systems, which form the majority population of DSSs in the USA for interim storage of spent nuclear fuel. Consideration of potential degradation of the welded stainless-steel canister in these systems is required for continued usage in the period of extended operation (PEO) beyond their initial licensed or certified terms. Challenges with performing the periodic examinations are associated with physical access to the canister surface, which is constrained due to narrow annulus spaces between the canister and the overpack, tortuous entry pathways, and high temperatures and radiation doses that can be damaging to materials and electronics. Motivations for performing periodic examinations and developing robotic crawlers for performing those examinations remotely will be presented, and several activities to demonstrate robotic crawlers for different DSS systems are summarized.


2021 ◽  
Author(s):  
Ryan M. Meyer ◽  
Jeremy Renshaw ◽  
Kenn Hunter ◽  
Mike Orihuela ◽  
Jim Stadler ◽  
...  

Abstract This paper describes development and demonstration of nondestructive examination (NDE) technologies to support periodic examinations of interim dry storage system (DSS) canisters for spent nuclear fuel in the USA to verify continued safe operation and that the canister confinement is intact and performing its intended safety function. Specifically, this work relates to NDE technology development for “canister” based DSS systems, which form the majority population of DSSs in the USA for interim storage of spent nuclear fuel. Consideration of potential degradation of the welded stainless-steel canister in these systems is required for continued usage in the period of extended operation (PEO) beyond the initial license or certified term. Physical access to the canister surface is constrained due to narrow annulus spaces between the canister and the overpack, tortuous entry pathways, and high temperatures and radiation doses that can be damaging to materials and electronics related to inspections. Several activities to demonstrate NDE technologies for the inspections of different DSS systems are summarized.


Author(s):  
William H. Lake ◽  
Nancy Slater-Thompson ◽  
Ned Larson ◽  
Franchone Oshinowo

Technology development activities are being conducted by the Department of Energy, Office of Civilian Radioactive Waste Management to support spent nuclear fuel and high-level radioactive waste transport to the federal repository at Yucca Mountain, Nevada in 2010. The paper discusses the motivation for pursuing transport technologies for a private sector operated transportation program, and describes some of the current technologies being pursued.


2015 ◽  
Vol 816 ◽  
pp. 103-107
Author(s):  
Jozef Bocko ◽  
Pavol Lengvarský

The paper is devoted to the description of project of storage system for the spent nuclear fuel. The proposed dry storage system is based on the natural convection of air so no additional fans are needed for the cooling. In the paper basic parameters of the storage as well as some preliminary computations verifying its concept are described.


2019 ◽  
Vol 96 (9) ◽  
pp. 888-892
Author(s):  
Aleksandr F. Bobrov ◽  
S. M. Kiselev ◽  
V. U. Shcheblanov

The paper deals with the quantitative assessment of the safety culture at facilities involved in the disposal of spent nuclear fuel and radioactive waste. Based on the method of the “internal” assessment of the safety culture, being developed in the A.I. Burnazyan Federal Medical Biophysical Centre, Moscow, 123182, Russian Federation, the comprehensive evaluation of the safety culture has been carried out with respect to the personnel of the following facilities: the Northwest Center for Radioactive Waste Management - SevRAO (NWC SevRAO) and the Far Eastern Center for Radioactive Waste Management- DalRAO (FEC DalRAO), which are subsidiaries of the RosRAO Enterprise.


2021 ◽  
Vol 2021 ◽  
pp. 1-25
Author(s):  
Shadwan M. M. Esmail ◽  
Jae Hak Cheong

In the planning and management of the interim storage of spent nuclear fuel, the technical and economic parameters that are involved have a significant role in increasing the efficiency of the storage system. Optimal parameters will reduce the total economic costs for countries embarking on nuclear energy, such as the UAE. This study evaluated the design performance and economic feasibility of various structures and schedules, to determine an optimal combination of parameters for the management of spent nuclear fuel. With the introduction of various storage technology arrangements and expected costs per unit for the storage system design, we evaluated eight major scenarios, each with a cost analysis based on technological and economic issues. We executed a number of calculations based on the use of these storage technologies, and considered their investment costs. These calculations, which were aligned with the net present value approach and conducted using MS Project and MATLAB software programs, considered the capacities of the spent fuel pools and the amount of spent nuclear fuel (SNF) that will be transferred to dry storage facilities. As soon as they sufficiently cool, the spent nuclear fuel is to be stored in a pool storage facility. The results show that applying a centralized dry storage (CDS) system strategy is not an economically feasible solution, compared with using a permanent disposal facility (PDF) (unless the variable investment cost is reduced or changed). The optimal strategy involves operating a spent fuel pool island (SFPI) storage after the first 20 years of the start of the permanent shutdown of the reactor. After 20 years, the spent fuel is then transferred to a PDF. This strategy also results in a 20.9% to 26.1% reduction in the total cost compared with those of the other strategies. The total cost of the proposed strategy is approximately 4,307 million USD. The duration of the fuel storage and the investment cost, particularly the variable investment cost, directly affect the choice of facility storage.


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