Radioisotope Inventory Of Spent Nuclear Fuel In Mathematica

Lartonoix, David

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https://hdl.handle.net/2142/31990 Copy

Description

Title

Radioisotope Inventory Of Spent Nuclear Fuel In Mathematica

Author(s)

Lartonoix, David

Issue Date

2012-06-27T21:23:24Z

Director of Research (if dissertation) or Advisor (if thesis)

Singer, Clifford E.

Department of Study

Nuclear, Plasma, & Rad Engr

Discipline

Nuclear, Plasma, Radiolgc Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• spent nuclear fuel
• radioisotope inventory

Abstract

While nuclear reactors in the United States have produced economy-driving power for several decades, they have also left behind a significant amount of spent nuclear fuel. The federal government, ultimately responsible for this spent fuel, has a history just as long in attempting to effectively bury, dispose, reprocess, or otherwise deal with this waste. As no attempts to date have been entirely successful, work continues to find an effective waste management solution. To aid planners, policymakers, and scientists in this endeavor, tools are currently needed to model the radioisotope inventory of all spent nuclear requiring disposal or other forms of remediation to accurately frame the scope of the issue. This project describes a simple method of calculating radioisotope concentrations in spent fuel by utilizing a unique approach to solving the diffusion equation eigenvalue problem. Herein, the dissolved boron concentration, essentially a chemical shim, is adjusted over an operational time period to maintain criticality in the reactor, compensating for fuel burnup, burnable poison burnout, and actinide and fission product buildup. It is shown, as an example, that the fractional reduction in boron concentration after a month of reactor operation is 2.3%. The normalized neutron flux in the example scenario is calculated and confirmed to be relatively flat radially and vertically. Similarly, the normalized thermal energy production rate is also shown to be relatively flat, as expected. Radionuclides of interest are tracked and isotopic concentrations are shown at various vertical heights within the core. Upon further refining, these concentrations can be taken to represent the radioisotope inventory of spent nuclear fuel under various burnup scenarios. Ultimately, characterizing the spent fuel requiring disposal will aid in developing an efficient waste management strategy. Even while several shortfalls are noted and described, tools such as this computer code can play a useful role in addressing the nation's nuclear waste disposal dilemma.

Graduation Semester

2012-05

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http://hdl.handle.net/2142/31990

Copyright and License Information

Copyright 2012 David Lartonoix

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