Year
2005
Abstract
The International Atomic Energy Agency (IAEA) and Ukraine discussed the issue of safeguarding nuclear material at the Chernobyl Unit 4 \"Shelter\" for many years. Ukraine submitted an updated Initial Inventory Declaration for Chernobyl Unit 4 including fresh fuel, core fuel, and spent fuel in 1998. It took into account nuclear production and loss with estimated plutonium content and uranium burn up, respectively, as of the date of the accident. It did not take into account any losses of the nuclear material in the Shelter since the time of the accident or the whereabouts of that material. These figures contain an uncertainty in the amount of material in the Shelter that has precluded the use of traditional, accountancy-based safeguards. A team of experts from the United States, IAEA, and Ukraine has created a unique plan to implement safeguards at Chernobyl Unit 4 based on containment and surveillance. The team developed a safeguards approach methodology that was based on analysis of the characteristics and locations of the damaged fuel to determine the safeguards need for the Shelter. The team studied the open literature on Chernobyl fuel containing materials and planned a unique chemical analysis of samples of the damaged core material. The team also performed experiments to assess the feasibility of radiation monitoring and surveillance equipment in the Unit 4 reactor central hall designed to verify that material in the Shelter has not been disturbed.