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The Tokaimura Nuclear Accident Mark as Favorite (40 Favorites)

PROJECT in Radiation. Last updated October 05, 2020.


In this project, students will use their knowledge of nuclear chemistry to read primary sources and write a claim, evidence and reasoning statement to support their determination as to whether the Tokaimura Nuclear Accident was the result of company or worker negligence.

Grade Level

High School

NGSS Alignment

This project will help prepare your students to meet the performance expectations in the following standards:

  • HS-PS1-8: Develop models to illustrate the changes in the composition of the nucleus of the atom and the energy released during the processes of fission, fusion, and radioactive decay.
  • HS-PS4-4: Evaluate the validity and reliability of claims in published materials of the effects that different frequencies of electromagnetic radiation have when absorbed by matter.
  • Scientific and Engineering Practices:
    • Asking Questions and Defining Problems
    • Analyzing and Interpreting Data
    • Engaging in Argument from Evidence
    • Obtaining, Evaluating, and Communicating Information


By the end of this project, students should be able to:

  • Write a correct claim, evidence and reasoning statement.
  • Use their knowledge of nuclear chemistry to determine if the workers or the power plant company is at fault in this nuclear accident.

Chemistry Topics

This project supports students’ understanding of:

  • Nuclear energy
  • Effects of radiation on the body


Teacher Preparation: 5-10 minutes making copies
60 mins


  • Copies of the primary source documents (1 set per group of 4 students)
  • Student copy of claim, evidence and reasoning handout (1 per student)
  • Student graphic organizer (1 per student)


  • No safety considerations necessary for this project.

Teacher Notes


  • To introduce this project I first show the students a short portion of the documentary (3 minutes) to peak their interest.
  • Then, the students are given a folder of the primary documents that are available for their review. Two versions of the documents (advanced and standard) are available based on ability level of students.
  • As students read these documents, they should fill out the graphic organizer and then complete the claim, evidence and reasoning handout.
  • Students that have experience with claim, evidence and reasoning may not need the handout or the graphic organizer.
  • Extension ideas:
    • Discuss determinations as a class.
    • Watch the entire documentary.
    • Discuss actual outcomes as a class. A few notable points :
      • The IAEA deemed the cause of the accidents to be, “human error and serious breaches of safety principles,” due to poor management of operations manuals, failure to train technicians and engineers, and improper procedures.
      • In April 2001, six employees were charged with negligence resulting in death.
      • More than $121 million was paid by the company to settle claims to those affected by the radiation exposure.

For The Student

Tokiamura Nuclear Accident: Graphic Organizer

Tokiamura Nuclear Accident: CER


I think ____________________________ (Mr. Ouchi or Tokiamura Nuclear Power Plant) is the one at fault in the death of Mr. Ouchi and his coworkers.

Evidence (describe each paper you are using out of the evidence folder)

Piece #1:

Piece #2:

Piece #3:


Piece #1: This piece of evidence shows that ______________ (Mr. Ouchi or Tokiamura nuclear power plant) is at fault in this accident because

Piece #2: This piece of evidence shows that ______________ (Mr. Ouchi or Tokiamura nuclear power plant) is at fault in this accident because

Piece #3: This piece of evidence shows that ______________ (Mr. Ouchi or Tokiamura nuclear power plant) is at fault in this accident because