Volume 9, Issue 5 (May 2012)

    Neutron Flux Reduction Programs for Reactor Pressure Vessel of Korea Nuclear Unit 1

    (Received 28 June 2011; accepted 8 February 2012)

    Published Online: 2012

    CODEN: JAIOAD

      Format Pages Price  
    PDF Version 10 $25   ADD TO CART


    Abstract

    The objective of this work is to implement various fast neutron flux reduction programs on the beltline region of the reactor pressure vessel to reduce the increasing rate of reference temperature for pressurized thermal shock (RTPTS) for Korea Nuclear Unit 1. A pressurized thermal shock (PTS) event is an event or transient in pressurized water reactors (PWRs) causing severe overcooling (thermal shock) concurrent with or followed by significant pressure in the reactor vessel. A PTS concern arises if one of these transients acts in the beltline region of a reactor vessel where a reduced fracture resistance exists because of neutron irradiation. Generally, the RTPTS value is continuously increasing according to the fast neutron irradiation during the reactor operation, and it can reach the screening criterion prior to the expiration of the operating license. To reduce the increasing rate of RTPTS, various neutron flux reduction programs can be implemented, which are focused on license renewal. In this paper, neutron flux reduction programs, such as low leakage loading pattern strategy, loading of neutron absorber rods, and dummy fuel assembly loading are considered for Korea Nuclear Unit 1, of which the RTPTS value of the leading material (circumferential weld) is going to reach the screening criterion in the near future. To evaluate the effects of the neutron flux reduction programs, plant and cycle specific forward neutron transport calculations for the various neutron flux reduction programs were carried out. For the analysis, all transport calculations were carried out by using the DORT 3.1 discrete ordinate code and BUGLE-96 cross-section library.


    Author Information:

    Yoo, Choon Sung
    Principal Researcher, Korea Atomic Energy Research Institute (KAERI), Yuseong-gu, Daejeon

    Kim, Byoung Chul
    President, Korea Reactor Integrity Surveillance Technology (KRIST), Yuseong-gu, Daejeon


    Stock #: JAI104176

    ISSN: 1546-962X

    DOI: 10.1520/JAI104176

    ASTM International is a member of CrossRef.

    Author
    Title Neutron Flux Reduction Programs for Reactor Pressure Vessel of Korea Nuclear Unit 1
    Symposium , 0000-00-00
    Committee E10