[Report] Visiting the Taebaek URL Site: The First Step Toward Building a High-Level Radioactive Waste Repository

To Be Built in Taebaek Goweon Natural Recreation Forest
Project Worth 647.5 Billion Won; Construction to Begin Next Year After Feasibility Study
Safety of Disposal System to Be Verified Before Final Site Selection
Some Raise Concerns Over Suitability of Taebaek Site
Korea Radioactive Waste Agency: "R&D Conducted on Various Rock Types Overseas"

Professor Sanghoon Kwon of Yonsei University's Department of Earth System Sciences (second from the right in the photo), who participated in the site suitability evaluation subcommittee of the Underground Research Laboratory (URL) site selection evaluation committee, is explaining to the press about the site where the drilling investigation was conducted. Photo by Heejong Kang

On August 13, I visited the Goweon Natural Recreation Forest in Cheoram-dong, Taebaek City, Gangwon Province. After driving for a while along the winding unpaved road past the 'Forest House' visitor accommodations, a clearing covered in dense vegetation appeared.

"This is the candidate site for the Underground Research Lab (URL) for the construction of a high-level radioactive waste repository. We drilled four boreholes here to conduct geological surveys," explained Lee Jaehak, Head of the High-Level Project Division at the Korea Radioactive Waste Agency, who accompanied us.

By 2032, an underground research facility will be established in the Taebaek Goweon Natural Recreation Forest, a place that attracts tourists year-round seeking relaxation in nature. The plan is to build a massive research facility with a ground area of 36,000 square meters and an underground area of 60,000 square meters, funded by 647.5 billion won from the national budget. Above ground, research buildings, a visitor center, an auditorium, and accommodations will be constructed, while underground, deep research modules will be installed.

Aerial perspective of the underground research facility (URL) to be built in Taebaek Cheoram-dong Goweon Natural Recreation Forest. Korea Radioactive Waste Agency

The Korea Radioactive Waste Agency is preparing to apply for a preliminary feasibility study to the Ministry of Science and ICT after selecting Taebaek City as the final URL site in December last year. On August 13, Cho Seongdon, President of the Korea Radioactive Waste Agency, met with the press on site in Taebaek and explained, "The Taebaek URL marks the first step toward constructing a high-level radioactive waste repository (HLW repository) following the passage of the Special Act on High-Level Radioactive Waste Management."

At the underground research facility, the safety of the disposal system will be studied and necessary technologies developed in an environment similar to the geological conditions of a future repository, before constructing an actual high-level radioactive waste repository. Article 30 of the Special Act on High-Level Radioactive Waste Repository also mandates the construction of an underground research facility for research purposes.

The underground research facility will be built separately from the actual disposal facility. It will not receive spent nuclear fuel but will use materials similar to radioactive substances to develop disposal technologies, essentially serving as a form of clinical trial. Once the actual HLW repository site is selected, an underground research facility will be built at the repository site to study the geological characteristics and safety of the radioactive waste disposal site.

The Korea Radioactive Waste Agency plans to open the underground research facility to the public to enhance understanding of high-level radioactive waste management.

Concept of Underground Research Laboratory (URL) for Research Purposes. Korea Radioactive Waste Agency

Since June last year, the Korea Radioactive Waste Agency has conducted a public call, received letters of intent and proposals, formed a site selection evaluation committee, evaluated the proposals, and reflected the results of geological surveys, ultimately selecting Taebaek City as the final candidate site for the underground research facility in December last year. Seven metropolitan governments and ten local governments participated in the project briefing, but the Gangwon-Taebaek consortium was the only one to submit a formal proposal.

The Korea Radioactive Waste Agency first evaluated the proposal submitted by Taebaek City, then conducted on-site investigations such as drilling surveys and geophysical explorations. The site selection evaluation committee unanimously concluded that the site was suitable for facility construction. The committee consisted of 20 experts in nuclear power, geology, environment, administration, law, and civil society, recommended by relevant agencies and academic societies.

The evaluation score was 93.87 out of a possible 105 points. According to the Korea Radioactive Waste Agency, the most important criterion during the evaluation process was the suitability of the rock type. This accounted for 25 points (including 3 bonus points) out of the total 105, making it the highest-weighted category. The final rock type suitability score, based on both the proposal evaluation and drilling results, was 24.145 points.

In terms of public acceptance and local government support, the site received 19 out of 20 possible points. Park Sujeong, Secretary-General of the Citizens' Coalition for Administrative Reform, who participated in the evaluation committee, explained, "Taebaek City has faced the risk of regional decline since the closure of coal mines, so not only the local government but also the residents were highly motivated."

Kim Hakjo, Director of National Policy Promotion at Taebaek City Hall, stated, "Including R&D, the Taebaek URL project will involve over 1 trillion won in investment, is expected to generate 300 billion won in economic benefits, and create more than 8,000 jobs. Together with Taebaek's Clean Methanol Future Resource Cluster and Forest Timber Cluster initiatives, we expect this project to attract young talent and revitalize the local economy."

At the core storage facility near the Taebaek site, which the press visited the previous day, it was possible to visually inspect rock samples extracted from deep underground during the drilling survey.

Kwon Sanghoon, Professor of Earth System Sciences at Yonsei University and a member of the site selection evaluation committee, explained, "At depths of 480 to 700 meters underground, we found hard granitic gneiss formed during the Precambrian era, the oldest geological period in Korea." Above this layer, sedimentary and volcanic rocks were found.

The appearance of the drilling core (rock) extracted during the drilling survey within the site of the Taebaek City Cheoram-dong Gowon Natural Recreation Forest. Granitic gneiss was confirmed at approximately 480 to 700 meters underground. Photo by Kang Heejong

Some concerns were raised when Taebaek was selected as the site for the underground research facility.

Recently, the Special Committee on High-Level Radioactive Waste Response of the Korean Nuclear Society pointed out that the upper layer above the disposal facility (where radioactive waste is safely stored) at the Taebaek site is sedimentary rock, not granite. Since Korea has conducted research for the past 30 years on the assumption that disposal sites would be located in granite bedrock, there are concerns that data from the Taebaek underground research facility may not be fully utilized during the future licensing process for a permanent repository site.

In response, Professor Kwon Sanghoon of Yonsei University explained, "Given Korea's geological structure, it is difficult to find a location where the entire upper and deeper layers are uniformly composed of granite. If a site with a similar geological structure is selected for the permanent repository in the future, the Taebaek site may actually be suitable."

Kim Jinha, Head of the URL Promotion Team at the Korea Radioactive Waste Agency, added, "Some experts believe that sedimentary rock can serve as a cap rock, inhibiting the movement of radioactive nuclides. This aspect will also be a subject of future research."

Deep borehole drilling and investigation for the research site are being conducted near the Taebaek Cheoram-dong High Plateau Natural Recreation Forest. Boreholes are drilled up to 1km deep to study the geology. This project is being promoted to secure drilling technology necessary for selecting a radioactive waste disposal site in the future. Photo by Kang Heejong

According to domestic technical standards, the key requirement is that the disposal facility be centered on a single bedrock type, so the presence of various rock types in the upper layers is not considered a problem. The Korea Radioactive Waste Agency notes that overseas facilities such as Japan's Mizunami URL, Switzerland's Mont Terri research facility, and Swiss repository candidate sites are also conducting research and development in locations where various rock types are present in the upper layers.

Meanwhile, with the Special Act on Radioactive Waste coming into effect this September and construction of the underground research facility set to begin next year, the long journey toward building a radioactive waste repository has begun. The government will establish a High-Level Radioactive Waste Management Committee under the Prime Minister's Office and begin the site selection process for the repository. Cho Seongdon, President of the Korea Radioactive Waste Agency, stated, "Once the committee is launched, our agency will serve as a support organization. We are currently developing plans for assessing the suitability of high-level radioactive waste repository sites."