Operation of the High-Temperature Engineering Test Reactor Nozomu Fujimoto, Naoki Nojiri, Yukio Tachibana and Toshihiko Mizushima Department of HTTR Japan Atomic Energy Agency (JAEA) -1-
Contents 1. 1. Outline of of the HTTR (HTTR :: High Temperature Engineering Test Reactor) 2. 2. Power-up test and achievement of of 950 C 3. 3. Maintenance experience 4. 4. Future plan 5. 5. Summary -2-
1. Outline of the HTTR HTTR Graphite-moderated/helium gas-cooled HTGR Control room Major specification Thermal power 30 MW Fuel Coated fuel particle / Prismatic block type Core material Graphite Coolant Helium Inlet temperature 395 C Outlet temperature 950 C (Max.) Pressure 4 MPa Intermediate heat exchanger (IHX) Spent fuel storage pool Containment vessel Reactor pressure vessel History First criticality : 1998 Full power operation : 2001 Safety demonstration test : 2002 High temperature operation (950 C) : 2004-3-
Block Type Fuel of the HTTR Fuel block -4-
Cooling System of the HTTR Single loaded operation : PPWC Parallel loaded operation : PPWC + IHX -5-
2. Power-up test and achievement of 950 C 2000 2001 2002 2003 4 5 6 7 8 9 10 1112 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 1112 1 2 3 4 5 6 7 8 910 11 12 1 2 3 2004 4 5 6 7 8 9 10 11 12 1 2 3 Rated operation mode 10MW 340 C* 1 16.5MW 500 C* 1 Reactor scram Rated operation mode High temperature test operation mode 20MW 600 C* 1 20MW 670 C* 1 Reactor scrammed due to loss of off-site electric power Rated operation mode 30MW 850 C* 1 Rated power operation 30MW 850 C* 1 Safety demonstration test 15MW Exchange for new HGC flirter. Rated power operation 30MW 850 C* 1 Reactor scram Rated power operation 30MW 850 C* 1 Safety demonstration test 10MW 18MW High temperature test operation mode 30MW 950 C* 1 Exchange for new N.S. Reactor scram Annual inspection *2*3 *2 *2*3 Annual *2 *3 inspection *2 *3 *3 *2 Annual inspection *3 *2 Annual Annual inspection inspection *2 *2 *3 *2 *1: Reactor outlet temperature, *2: Single loaded operation, *3: Parallel loaded operation -6-
Achievement of 950 C 50 45 40 Reactor Outlet Coolant Temperature 1000 900 800 Reactor Power (MW) 35 30 25 20 15 10 5 0 Reactor Power 31-May 5-Jun 10-Jun 15-Jun 20-Jun 25-Jun 30-Jun Date (2004) 700 600 500 400 300 200 100 0 Temperature ( C) Power-up tests at 950 o C were completed, and JAEA received an operation permit for the high-temperature test operation (950 o C operation) from the government. (June 24, 2004) -7-
Fuel performance Fractionalrelease of 88 Kr [-] 1.5E-08 1.0E-08 5.0E-09 Rated/Single loaded Rated/Parallelloaded High-tem p./single loaded H igh-tem p/p arallelloaded 0.0E+00 0 20 40 60 80 100 R eactor pow er [%] -8-
Change in excess reactivity with burn up 6.0 Excess reactivity [% Δk/k] 5.0 4.0 3.0 2.0 1.0 : Design : Measured 0.0 0 2000 4000 6000 8000 10000 Burnup [MWd/t] -9-
Chemical impurities in primary coolant 10.00 Reactor power 100 90 Impurity concentration [ppm ] 1.00 0.10 H 2 O CO CO 2 80 70 60 50 40 30 20 R eactor pow er [%] 10 0.01 0 2004/3/31 2004/4/5 2004/4/10 2004/4/15 2004/4/20 2004/4/25 2004/4/30 2004/5/5 Date -10-
3. Maintenance experience The HTTR has been operated about eight years since the first criticality achieved. Many maintenance works have been carried out. Typical maintenance works for the improvement of the HTTR plant performance Filter exchange of primary gas circulator Maintenance for reserved shutdown system Neutron detector replacement -11-
4. Future plan 2007 2020 High temperature gas reactor technology development(httr) The achievement of nuclear reactor exit temperature 950 o C(The first in the world) Safety demonstration tests Long high-temp. operation to grasp reactor characteristic Accumulation of operation, management maintenance technology Hydrogen Production with HTTR-IS System (1000m 3 /h) Commercial HTGR System Hydrogen production for commercial use in 2020s IS method hydrogen production technology development A design study of cogeneration system Design of GTHTR300-Cogeneration Research and development of compressor and magnetic bearing -12-
Future operation plan 2007 30 days operation (850 C, Parallel loaded operation) 2008 Safety demonstration tests (All G/C stop, 9MW) 50 days operation (950 C, Parallel loaded operation) 2009 Safety demonstration tests (All G/C & VCS stop, 9MW) -13-
Purpose of Long High-temp.(50days/950 o C) Operation Operation Operation and and Tests Tests of of HTTR HTTR Core Core Physics Physics He He Chemistry Chemistry Fuel Fuel & & Materials Materials Integrity Integrity Operation Operation & & Maintenance Maintenance Technique Technique Inherent Inherent Safety Safety Obtain Obtain Data Data for for HTGR HTGR Development Development Core Core Physics Physics :: Excess Excess reactivity reactivity and and other other core core physics physics parameters parameters change change by by fuel fuel burn-up burn-up He He Chemistry Chemistry :: Impurities Impurities behavior behavior at at high high temperature temperature under under radiation radiation environment environment Performance Performance of of primary primary He He purification purification system system Fuel Fuel and and Materials Materials Integrity Integrity :: FP FP release, release, High High temp. temp. component component (IHX), (IHX), In-core In-core components components (Graphite (Graphitecore core support support and and reflectors) reflectors) Operation Operation and and Maintenance Maintenance Technique Technique :: Control Control of of primary primary coolant coolant (Leak, (Leak, Purification, Purification, ) ) -14-
5. Summary JAEA is promoting R&Ds on HTGR which has salient inherent safety features and can be used for various nuclear heat utilization. The HTTR, the first HTGR in Japan, achieved the reactor outlet coolant temperature of 950 C in April 2004. Many kinds of operation and maintenance data of the HTTR are now being accumulated. Demonstration of hydrogen production with HTTR will be performed in near future. -15-
Thank you for your attention. -16-