MICHIGAN MEMORIAL PHOENIX PROJECT THE UNIVERSITY OF MICHIGAN MODIFICATION OF THE FORD NUCLEAR REACTOR FOR 10 MEGAWATT OPERATION Volume I Robert D. Martin ANN ARBOR MICHIGAN December, 1973 MODIFICATION OF THE FORD NUCLEAR REACTOR FOR 10 MEGAWATT OPERATION Robert D. Martin Submitted in partial fulfillment of the degree Nuclear Engineer at The University of Michigan December, 1973 Project Advisor: Dr. William Kerr ABSTRACT The modifications to the Ford Nuclear Reactor (FNR) Facility necessary to operate that reactor at a steady state power level of 10 Megawatts are described. The changes needed are outlined in detail, where possible, and the areas where further engineering or developmental work is required are identified and discussed. Based on the design changes proposed, a Design Basis Accident (DBA) is described and the consequences of the DBA analyzed. The report concludes that the location of the FNR on the North Campus of The University of Michigan will, with the recommended design changes, satisfy the site criteria outlined in 1OCFR100. It is recommended that a prompt determination be made of the extent to which this facility will have to conform to the standards for tornado and earthquake resistance and to perform any necessary structural analyses indicated. The results of these determinations will then dictate whether or not additional final design efforts are warranted. " 1 TABLE OF CONTENTS SECTI ON FPAGE Abstract................................................................ rable of Contents.................................................... x Figure List. .. .. .. .. .. ... .. .. .. .0. .. .. .. ......... .... 0... ... xv Table List. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .". .". .. .". ............... 0 1. INTRODUCTION 1.1 General Background....."........".............."........s 1 1.2 Other Designs Considered. .. .. ............ e..............." 2 1 .2.1 MvTR.. .... .. .. .. .. .. .. .. .. .. .. .. .. .... .. .. .. 3 1.2.2, TRIGA.".......".........."............"......... 4 1.2.3 PULS TAR .... .. .. .. .. .. .. .... .. .. .. .. .. ....... 5 1.3 Comparison .... .... .. .. .. .. ...... .. .... .. .. .... ..... 6 2. REACTOR SITE 10 2.1 Location. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. .... 10 2.2 Population Density - General Area ....................0*00 ... 2.3 Population Density -Reactor-Site Area ...................... 11 2.4 Site Topography...................."..........."..."..... 12 2.5. Site Climatology -General Area. .. .. .. .. .e. .. .. .. .. .. .... 13 22 2.6 Site Geology ."....."........................... 2.7 Site Meteorology........"....".......................... 25 3. BUILDINGS 3.1 General Comments .a......"as..........e... Go........ 27 3.2 Reactor Building Structural Design.............. ... .". .. ... 28 3.3 Auxiliary Building....................................e 32 o" TABLE OF CONTENTS (cont.) SECTION PAGE 4. REACTOR FACILITY CONTAINMENT 4.1 General Features of Containment System ................... 35 4.2 Containment Line Penetrations ............................... 36 4.2.1 General.......................................... 36 4.2.3 Experimental Facilities .............................. 38 4.2.4 Ventilation Ductwork ............................... 39 4.2.5 Personnel and Equipment Access...................... 41 4.3 Containment Ventilation Systems .............................. 44 4.3.1 Normal Ventilation System ............................ 44 4.3.2 Emergency Ventilation System......................... 46 4.3.3 Hot Off-Gas System ................................ 49 5. REACTOR CORE AND CORE EXPERIMENTAL FACILITIES 5.1 General Arrangement.......................................51 5.2 Core Support Structure .................................... 52 5.4 Core Irradiation Facilities................................... 54 6. EXPERIMENTAL FACILITIES EXTERNAL TO CORE 6.1 Pneumatic Tube System ....................................... 56 6.2 Radial Beam Ports ......................................... 57 6.3 Access Ports .............................................. 59 6.4 Heavy Water Reflector Tank .................................. 60 6.5 Support Structure Irradiation Facilities ......................... 60 6.6 Reactor-Pools........... .........................-----------. 61 iii TABLE OF CONTENTS (cont.) SECTION PAGE 7. NUCLEAR DESIGN AND THERMAL ANALYSIS 7.1 Nuclear Design........................................... 62 7.1.1 Core Type ......................................... 62 7.1.2 Fuel Element Design ................................ 62 7.1.3 Core Mass and Reactivity Coefficients.................. 65 7.1.4 Core Reactivity Accountability....................... 68 7.1.5 Core Arrangements................................. 68 7.2 Thermal Analysis ........................................... 70 7.2.1 General........................................... 70 7.2.2 Coolant Mass Flow.................................. 70 7.2.3 Coolant Characteristics .............................. 72 7.2.4 Heat Generation Rate ............................... 73 7.2.5 Hot Channel Considerations .......................... 74 7.2.6 Results of Calculations .............................. 75 7.2.7 Comparison With Measured Results ..................... 77 7.2.8 Thermal-Hydraulic Induced Problems.................. 77 8. PROCESS WATER SYSTEMS 8.1 General ................................................... 79 8.2 Reactor Coolant System ...................................... 80 8.2.1 Reactor Primary Water System'......................... 80 8.2.2 Reactor Shutdown Cooling System ...................... 84 8.2.3 Reactor Secondary Water System ....................... 85 8.3 HeavyWaterTankCoolingSystem............................87 8.4 Hot Water Layer and Pool Make-up Water Systems ................ 89 iv TABLE OF CONTENTS (cont.) SECTION .EPAGE r 8.5 Auxiliary Water Systems .................................... 91 8.5.1 Water Purification Systems ........................... 91 8.5.2 Pool Water Degasifier ............................... 93 8.5.3 Experimental Facility Cooling System................ 94 8.5.4 Thermal Shield Cooling .............................. 94 8.6 Emergency Water Systems .................................... 95 8.6.1 General........................................... 95 8.6.2 Auxiliary Building Storage Tank ...................... 95 8.6.3 City Water Line .................................... 96 8.6.4 Core Spray System .................................. 97 8.6.5 Anti-Siphon Valve............................... 97 9. INSTRUMENTATION and CONTROL 9.1 General ...................... ......................... 98 9.2 Nuclear Instrumentation ........ .......................... 98 9.2.1 Typesof Systems .. ................................ 98 9.2.2 Start-up System ..................................... 99 9.2.3 Wide Range System................................ 100 9.2.4 Safety System ................................... 101 9.3 Process System Instrumentation ................................ 104 9.3.1 General........................................ 104 9.3.2 Reactor Primary Water System ................ 105 9.3.3 Reactor Shutdown Cooling System................... 105 9.3.4 Reactor Secondary Water System ...................... 108 9.3.5 Reflector Tank Cooling and Pool Hot Layer Systems..... 108 .9.3.6 Auxiliary System ................................... 108 9.3.7 Emergency Systems............................. 112 V TABLE OF CONTENTS (cont.) SECTION PAGE 9.4 Radiation Detection Instrumentation . ...... ..... ..... ........ ... 112 9.5 Ventilation System Instrumentation............................ 112 9.6 Reactivity Control........................................116 9.6.1 General Mode of Operation .......................... 116 9.6.2 Reactivity Control Device ............................. 118 9.6.2.1 Shim-Safety Rod ........................... 118 9.6.2.2 Rod Drive Mechanism......................118 9.6.3 Rod Withdrawal Inhibit Functions.....................119 9.6.4 Reactor Setback Functions ........................... 120 9.6.5 Rod Run-in Functions ................................ 121 9.6.5.1 General .................................. 121 9.6.5.2 Slow Speed Run-in ......................... 121 9.6.5.3 High Speed Run-in ........................ 121 9.6.6 Rod Scram Functions .................................. 122 9.6.6.1 General.................................. 122 9.6.6.2 Slow Scrams .............................. 122 9.6.6.3 Fast Scrams ............................... 123 9.6.7 Rod Drive Mechanism Control Circuit .................. 123 10. SHIELDING REQUIREMENTS 10.1 General ................................................... 125 10.2 Reactor Biological Shield .................................... 125 10.3 Reactor Basement Shielding .................................. 127 10.4 ReactorThermalShields...................................128 10.5 Emergency Ventilation System Shield ......................... 129 vi TABLE OF CONTENTS (cont.) SECTION* PAGE 11. FACILITY UTILITY SYSTEMS 11.1 General .................................................. 130 11.2 Electrical Supply Power and Distribution ...................... 130 11.2.1 General Features .................................. 130 11.2.2 Emergency Electrical Power ......................... 131 11.3 Water Supply ............................................ 133 11.4 Compressed Air Supply.....................-............. 133 11.5 Steam Supply ............................................. 134 11.6 Communications and Alarm Systems ......................... 135 12. LIQUID RADIOACTIVE