The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 26, 2005
Filed:
Mar. 28, 2003
Patrick J Stephens, Hellingham, WA (US);
Patrick J Stephens, Hellingham, WA (US);
Other;
Abstract
A method for grouting a decommissioned nuclear reactor containing residual water. A first, water-absorbent grout is used to grout the bottom portion of the reactor vessel. The water-absorbent grout is formed of cement and a water-absorbent particulate material, such as expanded perlite, exfoliated vermiculite or granulated bentonite. Excess water is absorbed by the particulate material, so that the residual water is incorporated in the fill material when it sets. A set retarder may be included to extend the time for uptake of residual water by the particulate material. Foam may also be included to reduce density and increase pumpability. The remaining, upper portion of the reactor vessel is grouted using lightweight cellular cement grout, lacking the water-absorbent particulate material, so that total weight of the fill remains low enough that the grouted vessel can be removed using the facility's installed crane system. Because the residual water is incorporated in the first, water-absorbent grout, the problem of residual water causing dissipation and collapse of the bubble structure in the lightweight cellular cement grout is obviated.