Replacement of the University of Missouri Research Reactor (MURR) Cooling Towers Les Foyto, Associate Director John Fruits, Reactor Manager Carl Herbold, Assistant Reactor Manager
Overview MURR Facility Cooling Tower History Tower Design Project Background and Timeline The Big Snag The Big Lag Lessons Learned Q & A
History of MURR Located in Columbia, Missouri October 13, 1966 Facility established initial criticality and licensed to operate at 5 MWs July 18, 1974 Facility uprated to 10 MWs September 1, 1977 Facility starts a 10 MW, 150-hour-per-week operating schedule September 1, 2006 Facility submits 20-year license renewal application to the NRC
Key Reactor Parameters MURR is a pressurized, reflected, heterogeneous, open pool-type, which is light-water moderated and cooled Maximum thermal power 10 MW Peak flux in center test hole 6.0E14 n/cm 2 -s Core 8 fuel assemblies (775 grams of U-235/assembly) Control blades 5 total: 4 boral shim-safety, 1 SS regulating Reflectors beryllium and graphite Forced primary coolant flow rate 3,750 gpm (237 lps) Forced pool coolant flow rate 1,200 gpm (76 lps) Primary coolant temps 120 F (49 C) inlet, 136 F (58 C) outlet Primary coolant system pressure 85 psia (586 kpa) Pool coolant temps 100 F (38 C) inlet, 106 F (41 C) outlet Beamports three 4-inch (10 cm), three 6-inch (15 cm)
Reactor Core Assembly 3-D View 2-D View
Funding for the Project Amount ~$84K Source Global Threat Reduction Initiative (GTRI) Reactor Conversion Program through a Work Order from Argonne National Laboratory This funding is part of the HEU/LEU fuel conversion project: Funded temporary cooling tower tie-ins Funded thermal-hydraulic study for new cooling towers ~$1.29 mil Funded purchase of new cooling tower Funded demolition of old cooling tower and installation of the new cooling tower Funded installation, rent and removal of temporary cooling towers Funded installation of data acquisition system
Previous Cooling Tower History 1964/65 Original 2 Cell Cooling Tower Installed 1973/74 3rd Cell added for 10 MW Power Uprate 1985 1998 Cooling Tower Refurbished Cooling Tower Refurbished 2004/05 Cooling Tower Electrical Upgrades 7
Project Background Activity GTRI lays groundwork via thermal design study and replacement cost estimate NEUP provides catalyst, which GTRI prepared us for University Campus Facilities provides project management, contracts designer and general contractor GTRI provides temporary tower connections University Procurement purchases new cooling towers University Procurement leases temporary towers
Tower Design
Tower Design
Tower Design Three cells Original Wood frame, induced-draft, cross-flow, PVC fill Concrete basin/sump Two-speed 40 HP fans Cools 4688 gpm (296 lps) From 104 deg-f (40 C) To 87 deg-f (31 C) At 77 deg-f (25 C) wet-bulb temperature Three cells Current Stainless Steel frame, induceddraft, cross-flow, PVC fill Elevated Stainless Steel basin Two-speed 40 HP fans Cools 5400 gpm (341 lps) From 115 deg-f (46 C) To 86 deg-f (30 C) At 80 deg-f (27 C) wet-bulb temperature
Date Activity Project Timeline 09/26/11 Commenced installation of temporary cooling towers 10/10/11 Placed temporary cooling towers on service 10/19/11 Commenced demolition of old cooling tower 10/24/11 Commenced Installation of new cooling tower 12/30/11 New cooling tower essentially complete 01/02/12 Placed new cooling tower on service 01/17/12 Commenced removal of temporary cooling towers 01/18/12 Temporary cooling towers removed
The Big Snag Week of October 10 th, 2011 Monday Thursday Friday-Sunday Placed temporary cooling towers on service Noted excess and growing volume of water in basement sump Noted excess water makeup on temporary cooling towers Secured temporary booster pumps to minimize losses DIG, DIG, DIG
The Big Lag Noted decrease in performance of the two parallel primary heat exchangers Frequent backflushing did not resolve or improve thermal performance **Reactor power was reduced for a period of weeks**
9/2006 8/2006 7/2007 9/2007 8/2007 7/2007 6/2008 7/2008 6/2008 5/2008 4/2009 6/2009 5/2009 4/2009 3/2010 5/2010 4/2010 3/2010 2/2011 4/2011 3/2011 2/2011 1/2012 2/2012 1/2012 0/2012 9/2013 Log Mean Temperature Difference The Big Lag 100% 90% Mechanical Cleaning on 503A 80% 70% 60% 50% 40% 30% 20% 10% 0% Installation of Temporary Towers 503B 503A 503 Average Plate Replacement on 503B
The Big Lag Roughly 240 lb (110 kg) of calcium scale was removed HX was reassembled and retested in 36 hours
Lessons Learned Don t replace your cooling tower
Lessons Learned Don t replace your cooling tower The one part of your system you have the least access to will be the part that breaks
Lessons Learned Don t replace your cooling tower The one part of your system you have the least access to will be the part that breaks Significant operational impacts from proper chemistry control
Lessons Learned Don t replace your cooling tower The one part of your system you have the least access to will be the part that breaks Significant impact to proper chemistry control Clear and knowledgeable communication on leased equipment
Thank You For Your Attention, Any Questions???