BWR spent fuel storage cask performance test. Volume 1. Cask handling experience and decay heat, heat transfer, and shielding data

Abstract

This report documents a heat transfer and shielding performance test conducted on a Ridihalgh. Eggers & Associates REA 2023 boiling water reactor (BWR} spent fuel storage cask. The experimental work was conducted for the U.S. Department of Energy's (DOE) Commercial Spent Fuel Management Program by the Pacific Northwest Laboratory (PNL} and General Electric at the latter's Morris Operation (GE-MO). The testing effort consisted of three parts: pretest preparations, performance testing. and post-test activities. Pretest preparations included conducting cask handling dry runs and characterizing BWR spent fuel assemblies from Nebraska Public Power District's Cooper Nuclear Station. The performance test matrix included 14 runs consisting of two loadings, two cask orientations, and three backfill environments. Post-test activities included calorimetry and axial radiation scans of selected fuel assemblies, in-basin sipping of each assembly, crud collection, video and photographic scans, and decontamination of the cask interior and exterior.The REA 2023 spent fuel storage cask consists of a double containment design with silicone rubber 0-rings for sealing the primary lid of the inner cavity and a welded final closure on the secondary cover. The cask has a smooth, painted, stainless steel outer skin; a lead/stainless steel gamma shield; and a water/glycol neutron shield. The fuel basket is constructed of stainless steel clad Boral for criticality control, copper plates to conduct heat to the cask wall, and stainless steel for structural strength. The loaded cask is approximately 5 m tall and 2.25 m in diameter. and weighs approximately 100 tons. The basket is configured to hold 52 BWR spent fuel assemblies. The test fuel assemblies were of the General Electric 7x7 rod design. The REA 2023 BWR spent fuel storage cask design and manufacturing rights have been acquired by Mitsubishi of Japan, and the cask model designation has been changed to MSF IV.Dry runs of cask handling were performed prior to fuel being loaded in the cask and concurrent with fuel calorimetry. The objectives of the dry runs were to gain cask handling and loading experience and to finalize procedures. Each dry run was conducted successfully without significant problems. During the dry v dry runs, minor modifications were required to make the lifting yoke, yoke alignment guide, impact limiter, primary head bolts, neutron shield rupturo-: disk, and the cask pressurizing device more functionai.The Cooper spent fuel assemblies were cnaracterized using in-basin si~p ing, calorimetry, axial radiation scans, video scans, and 35-mm photograph,!.The results of these methods revealed no indication of any failed fuel befcre or after the performance test. Gas sampling during testing did indicate a leak in a fuel rod after the cask was fully loaded. However, the leak was calctlated to be extremely small, so small that its source was not identifiable by post-test sipping activities, video scans, or photography.Based on pretest calorimetry, fuel assembly decay heat rat...

Spent nuclear fuel integrity during dry storage - performance tests and demonstrations

“…A summary of the core test conditions and peak fuel temperatures is found in Table 3.1. Axial and radial temperature profiles corresponding to the location of the peak temperature are contained in the original reports (Creer et al 1986;McKinnon et al 1986Wiles et al 1986;Strope et al 1990;McKinnon and DeLoach 1993). (a) Consolidated fuel -2:l consolidation ratio.…”

LLNL Input to SNL Report on the Composition of Available Data for Used Nuclear Fuel Storage and Transportation Analysis

“…The average basket temperature was used to predict thermal expansion in McKinnon et al (1989), and the gap conductance between fuel pellet and cladding is assumed constant (Rector and Michener, 1989). (Creer et al, 1987;McKinnon et al, 1986McKinnon et al, , 1989McKinnon et al, and 1992Rector et al, 1986 (Creer et al, 1987;McKinnon et al, 1986;Rector et al, 1986a;Rector et al, 1986b (Rector et al, 1986a) Cask stainless steel inner liner 0.6 (Lombardo et al, 1986) Cask surface (stainless steel) 0.3 (Rector et al, 1986b) In addition to uncertainty in standard/reference values for thermal properties, there also exists uncertainty in the temperature dependence. Several of the thermal properties are also a function of temperature and therefore change over time as the cask (and contents) cools and is subject to changes in atmospheric temperature.…”

“…2. Composition of Available Data and Models .............................................................................. 11 2.1 (Cuta and Adkins, 2014) and Cask Array (Easton, 2012) (Creer et al, 1987;McKinnon et al, 1986McKinnon et al, , 1989McKinnon et al, and 1992Rector et al, 1986) Table 2-3 Density, thermal conductivity and specific heat capacity of gases at 200°C (Incropera and DeWitt, 1990)........................................................................................................ 16 Table A-1 General description of maturity levels in PCMM elements (Oberkampf et al 2007).............................................................................................................................................…”

Initial evaluation of dry storage issues for spent nuclear fuels in wet storage at the Idaho Chemical Processing Plant

“…Criteria for the waste package and its comwnents (b) Specific criteria for HLW package design - (1) The waste package shall not contain explosive or pyrophoric materials or chemically reactive materials in an amount that could compromise the ability of the underground facility to contribute to waste isolation ... ( 2) The waste package shall not contain free liquid in an amount that could compromise the ability of the waste packages to contain the HLW. (4Xc) All radioactive wastes shall be in solid form.…”