Results to Date of the Dresden-1 Chemical Cleaning

  • David E. Harmer
  • Jerry L. White


After more than 18 years of commercial operation, Dresden-1 has now been shut down for an outage to reduce radiation levels and to perform various ISI activities and retrofitting tasks. One of the first tasks will be the complete chemical cleaning of the internal primary system to remove radioactive deposits from pipe and equipment.

The original objectives of the program included:
  1. 1.

    Reduce radiation levels to improve plant accessibility.

  2. 2.

    Ensure continued safe and efficient operation.

  3. 3.

    Develop and prove techniques applicable to other reactors.

  4. 4.

    Encourage vendor, manufacturer, and consultant participation.


Laboratory tests of the NS-1 solvent on samples of actual Dresden-1 internal surfaces have given radiation reduction in excess of 99%. A field result close to this efficiency is anticipated.

Plans for this chemical cleaning have been progressing since 1973. The cleaning solvent has been selected and tested. Process details and procedures are essentially complete. Construction activities went forward in two areas; new piping and equipment connections in the containment sphere, and an entirely new building to process the spent cleaning solvent and rinses. Photographs and drawings of these facilities are included.

The actual chemical cleaning of Dresden-1 is scheduled during early 1980. This date represents a moderate amount of slippage from the earlier target date. The new schedule, and results of the cleaning operations to date, are included in this report.


Steam Generator Decontamination Factor Chemical Cleaning Cleaning Operation Construction Schedule 
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  1. 1.
    W. S. Lange and T. L. Snyder, “Engineering Aspects of Dresden Unit 1 Chemical Cleaning Project” ANS Topical Meeting on Decontamination and Decommissioning of Nuclear Facilities, September 16–19, 1979Google Scholar

Copyright information

© Plenum Press, New York 1980

Authors and Affiliations

  • David E. Harmer
    • 1
  • Jerry L. White
    • 2
  1. 1.Dow Nuclear ServicesThe Dow Chemical CompanyMidlandUSA
  2. 2.Station Nuclear Engineering DivCommonwealth Edison CompanyChicagoUSA

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