General Electric Company

Eric Russel Willis

Sampath Ranganath

Paul Van Diemen

Henry Peter Offer

In a method for sealing a hollow, elongate member within a reactor pressure vessel of a nuclear reactor, a section of the elongate member may be removed to separate the elongate member into an upper portion and a lower portion with an opening there between. The lower portion may be attached to a surface of the reactor pressure vessel in-situ, so as to seal off a potential leakage path through the elongate member.

Methods of repairing leaking elongate hollow members in boiling water reactors

The method facilitates sealing a control rod drive (CRD) housing to a stub tube in a reactor pressure vessel of a nuclear reactor, if any cracks develop proximate a heat affected zone of the stub tube at a CRD housing re-attachment weld. The method includes cutting the CRD housing to separate an upper portion of the CRD housing from a lower portion of the CRD housing. The lower portion remains in place and in substantial alignment with the upper portion of the CRD housing. A lower portion member, which may be the lower portion that was cut, is re-attached to the reactor vessel by a re-attachment weld at a location below potential differential leakage paths along the CRD housing. The heat affected zone (e.g., at the re-attachment weld) is covered with a corrosion resistant material to prevent future leaking, and to protect the weld from inter-granular stress corrosion cracking (IGSCC).

Method of repairing leaking elongate hollow members in boiling water reactors

Electrical resistance welding with low heat input in conjunction with applied forces effecting compressive forces in the weld are utilized to weld materials sensitive to hot cracking. An electrode coupled with a force applicator performs a low heat input resistance-type weld with triaxial compressive forces introduced in the weld to prevent or inhibit the formation of tensile induced cracks in the weld. This enables subsequent fusion welding overlying the initial weld without risk of hot cracking in the final weld.

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San Jose, CA, United States of America

Eric Russel Willis