Gyeongju Compacted Bentonite for Engineered Barrier System (EBS)

 

▶ Introduction

 The increasing demand for nuclear energy in Korea is expected to grow in order to confront climate change. Thus the importance of the buffer material for EBS design of a nuclear waste repository is also increasing. The buffer material serves as an impermeable seal and installed between the canister and disposal hole inside the EBS. Overall, the mechanical properties of Gyeongju bentonite should be evaluated for the static and dynamic design

▶Testing Materials and Methods

 Highly compacted bentonite (KJ-II) with dry densities of 1.50g/cm3 to 1.77 g/cm3 with initial water contents of 8.7% to 11.5% to preserve actual construction conditions. The length to diameter ratio is 2:1 with dimension of 100mm and 50mm respectively.

 

 

 

▶ RC/TS Testing (2020-Present)

 

 A dynamic device that can measure small strain measurement at a range of 10-4% to 10-2%. These ranges of small strain measurement are relative to structural and earth vibrations such as machine foundations, ocean wave loading and earthquakes.

 

- Provide high accuracy of testing systems applicable to soft soils to soft rocks.

- To enhance the capacity of the torque actuator by developing the coil-magnet system.

- With the series  of measurements the goal is to have accurate measurements without having interference form external factors.

- To have an accurate (γ-G) diagram at increasing levels of shear strain.

- To have an accurate (γ-D) diagram at from the resonant frequency from each level of strain.

- To make the first RCTS Korean design guideline

 

 

 

▶ Biomass (2020-Present)

 

- Organic materials derived from nature

- Raw materials undergoes combustion

- Use as energy source then typically disposed

 

                                 Wood Ash

  

- Many studies with   ↑    CaO content > stable soil

- Waste product after combustion

- Potential Stabilizer

- Binder: acceptable mechanical & durability

- Can be used as partial replacement to: Ordinary Portland
- Cement (OPC)

- Self leveling

 

 

 Proposes a design guideline that will evaluate structural integrity and performance of natural soils mixed with the WA by both static and dynamic tests.