Experiments Carried-out, in Progress and Planned at the HTR-10 Reactor Yuliang SUN Institute of Nuclear and New Energy Technology, Tsinghua University Beijing 100084, PR China 1 st Workshop on PBMR Coupled Neutronics/Thermal Hydrolics Transient Benchmark The PBMR-400 Core Design, 16-17 June 2005, NEA/OECD, Paris
Contents Introduction of HTR-10 Experiments carried-out during commissioning and operation Safety demonstration experiments Experiments in progress and planned for the future
The HTR-10 Test Reactor I I
The HTR-10 Test Reactor 700/3.0 435/3.43 ST G 2.5MW SG 250/0.5 HTR-10 250/3.04 Heating grid 104/6.1 Condenser LP Heater Cooling Tower He Blower Deoxidiser HTR-10 Process Flow
HTR-10 Key Design Parameters Reactor thermal power MW 10 Reactor core diameter cm 180 Average core height cm 197 Graphite reflector thickness cm 100 Primary helium pressure MPa 3.0 Helium mass flow rate at full power kg/s 4.3 Average helium temperature at reactor outlet C 700 Average helium temperature at reactor inlet C 250 Main steam flow rate t/h 12.5 Main steam pressure at turbine inlet MPa 3.43 Main steam temperature at turbine inlet C 435 Feed water temperature C 104 Number of control rods in side reflector 10 Number of absorber ball units in side reflector 7 Nuclear fuel UO2 Heavy metal loading per fuel element g 5 Enrichment of fresh fuel element % 17 Number of fuel elements in equilibrium core 27,000 Fuel loading mode Multipass 5
HTR-10 Key Milestones Mar. 1992: HTR-10 project formally approved by government Jun. 1995: First concrete of reactor building Apr. 2000: Reactor internals and RPV upper head installed May 2000: Turbine-generator systems installed Dec. 2000: Initial criticality reached Jan. 2003: Full power operation Since Jan. 2003: operation, experiments, safety demonstration
HTR-10 In-core and Vessel Thermocouples
Experiments carried-out during commissioning Commissioning phases Phase A: Pre-operational tests 36 items Phase B: Fuel loading and low power physics test 44 items Phase C: Power operation test 20 items
Commissioning Phases Phase A A1: Subsystem or component function test A2: process system function test A3: preparation before fuel loading Phase B B1: fuel loading and first criticality B2: zero power physics experiment B3: low power experiment Phase C C1: 0~30% rated power experiments C2: 30~100% rated power experiments
1.5 Test Items Planed on Phase C Number Title of test item Phase 1 Verifying the function of cavity ventilation C1 2 Verifying the function of secondary circuit isolation valve C1 3 Impurity and radiation measurement C1 4 Measurement of neutron and gamma fields 5 Steam safety valve performance test C1 6 Hot functional test of secondary circuit C1 7 Startup/shutdown circuit and steam generator circuit switch test C1 8 Verifying the capacity of primary circuit cavity cooling C1, C2 9 Measurement of power coefficient C1, C2 10 Verifying the main design parameters C1, C2 11 Verifying the direction of natural circuit after shutdown C1, C2 12 Transient behavior of main helium circulator trip C1 13 Transient behavior of loss of off-site power C1 14 Grid synchronization C1 15 Thermal power calibration C1, C2 16 Power regulation test C2 17 Behavior test of loss of generator load C1, C2 18 Rated power level test C2 19 Verify HTR-10 shutdown means C2 20 Shut down margin measurement C2
Commissioning Milestones DATE April, 2000 November 20 th, 2000 December 26 th, 2000 July, 2002 August 15 th, 2002 December 31 st, 2002 January 1 st, 2003 January 26 th, 2003 Pre-operation test First fuel loading EVENT Reach first criticality in air atmosphere Criticality in helium atmosphere and zero power physics tests Low power and hot function tests Power escalation to 3MW Connecting to electric grid Reaching rated power of 10MW
Initial Criticality: Calculation Approaches Diffusion Approach with VSOP code system GAM: calculation of fast and epithermal spectrums THERMOS: calculation of thermal spectrum CITATION: finite mesh diffusion code solving the eigenvalue problem in 4 energy groups ZUT-DGL: generation of cross-sections of the resolved and unresolved resonances Nuclear data: ENDF/B-V and JEF-I Monte Carlo Approach with MCNP4A Modeling: three dimensional reactor model, hexahedron lattice of particles Nuclear data: ENDF/B-V Number of cycles: 140 number of source neutrons per cycle: 10,000 number of cycles skipped for collecting K eff : 5
Initial Criticality To be calculated and measured: Amount of core loading for the first criticality K eff =1.0 in terms of core loading height or number of loaded balls. Calculation Results: VSOP: 122.558 cm MCNP: 122.874 cm
Initial Criticality: Comparison between calculation and Experiment The first criticality experiment of HTR-10 was made in December 2000 with the extrapolation approach. In the experiment, first criticality is reached when a total number of 16,890 balls are loaded into the reactor core, of which 9,627 are fuel balls and 7,263 are dummy graphite balls, namely to the ratio of 57:43. This loading corresponds to a loading height of 123.06cm. (The core atmosphere is 15ºC air when first criticality is achieved.) Calculation with VSOP and MCNP predicts first criticality at a loading of mixed balls of 16,821 and 16,864 at 27ºC, respectively. The real air temperature is 15ºC while the initial criticality is achieved. After temperature coefficient correction, VSOP predicts a critical loading of 16,759 mixed balls which corresponds to a loading height of 122.11cm. The experimental critical loading is 16,890 mixed balls or 123.06cm in terms of loading height. The calculation error is very small and satisfying.
Full Power Operation Performance Parameter Design Test value value Thermal power (MW) 10 10.3 Pressure of primary circuit (MPa) 3.0 2.94 Outlet/inlet helium temperature of SG ( C) 250/700 237/700 Mass flow rate of water through SG (kg/s) 3.49 3.56 Pressure of steam (MPa) 4.0 3.45 Temperature of main steam ( C) 440 430 Temperature of feed water ( C) 104 99 Temperature of PRV ( C) <=250 220-240 Temperature in the helium blower cavity ( C) <=100 60 Temperature in the control rod drives cavity ( C) <=100 40 Temperature of RPV supports ( C) <=70 50
Measurements of Doses At power of 1MW,3MW,5MW,7.5MW and 10MW,measurements of the radiation levels within the plant are performed to verify the adequacy of the shielding design Measured are neutron, gamma dose rates in process rooms and working places, the gamma dose rates around the plant site and beta concentration of discharged gas from stack Results: all dose rates are far below the operation limits
Lose of Off-site Power Test The purpose of this test is to confirm The protection system can respond correctly, Required safety functions can be performed, The emergency power can provide electricity within one hour, The reactor and other main equipment such as helium blower are safe and to examine the adequacy of accident management procedures Initial test condition Power of 3MW the three entrance switches of central power supply were turned off
Lose of Off-site Power Test Result The protect system was triggered. Safety functions performed The outlet temperature of helium decreased rapidly. The temperature of Hein, PRV and SGPV decreased slowly. The temperatures of shielding, surface cooler outlet and air cooler outlet basically remained unchanged within the experiment time frame. The temperature of PV support increased by about 1 C. power (kw) temperature( C) 700 600 500 400 300 200 100 3000 2500 2000 1500 1000 0 500 0 14:52 15:21 15:50 16:19 16:48 17:16 tim e 14:52 15:21 15:50 16:19 16:48 17:16 time Heout Hein RPV SGPV PVSuport Sh ield in g Surface out Air cooler out
ATWS Safety Demonstration Tests The purpose of conducting these tests is to demonstrate the inherent safety features as well as to obtain the core and primary cooling system transient data for validation of transient analysis codes. Test items: Two ATWS scenarios were simulated: Loss of primary cooling (helium blower trip) without scram Reactivity insertion by withdrawal of one control rod without scram Test condition: 30% rated power
Loss of primary cooling without scram 3500 1400 3000 1200 Power(kw) 2500 2000 1500 1000 power(kw) speed(rpm) 1000 800 600 400 200 Speed (rpm) 500 0 0-300 1700 3700 5700 7700 9700 Time(s) -200 Transient of power after helium circulator trip
Loss of primary cooling without sram Temperature ( ) 700 600 500 400 300 200 100 0-300 1700 3700 5700 7700 9700 11700 Time (s) Transients of helium inlet and outlet temperatures after circulator trip
Reactivity insertion without scram Power(kw) 8000 7000 6000 5000 4000 3000 2000 1000 0 power(1mk) power(5mk) position(5mk) position(1mk) 0 30 60 90 120 150 180 Time(s) 3000 2500 2000 1500 1000 500 0 Rod poaition (mm Short term power transient during reactivity insertion without scram
Reactivity insertion without scram Power (kw) 8000 7000 6000 5000 4000 3000 2000 1000 0 position(5mk) position(1mk) power(5mk) power(1mk) -100 590 1190 1790 2390 2990 3590 4190 4790 5390 Tme (s) 3000 2500 2000 1500 1000 500 0 Position (mm Long term power transient during reactivity insertion without scram
Reactivity insertion without scram 900 800 700 outlet mixing room Temperature( ) 600 500 400 300 200 side reflector underside bottom reflector side reflector upside 100 0 Top bottom reflector reflector metal support -100 500 1100 1700 2300 2900 3500 4100 4700 5300 Time(s) Core temperature transients during reactivity insertion ATWS simulation
Experiments in progress and under planning Safety demonstration tests under rated power of 10MW Correlation between fuel fission product retention modeling and radioactivity intensity in primary helium Installation of He turbine-generator unit to the HTR-10 reactor
HTR-10 GT Objective To gain experience of HTRs with gas turbine cycle Steps Joint design with OKBM Installation of gas turbine cycle system Operation of gas turbine cycle
HTR-10 GT t=752.1 C Q=4.55 kg/s Reactor N=10 MW t=461.4 C Gas cooler N=0.17 MW Water for cooling t=20 C Q=2.213 kg/s t=501.5 C P=0.6825 MPa t=750 C G=4.66 kg/s P=1.5029 MPa Recuperator N =8.63 MW t= 97.8 C P=1.58 MPa Frequency converter Ne=2.02 MW Generator Ne=2.1 MW Turbine n=250 r/s N =5.727 MW Bypass valve HPC N=1.765 MW P=1.5312 MPa t= 330 C Steam to turbine Steam generator N=3.12 MW t= 144.6 C P=0.6635 MPa Precooler N=2.98 MW t=26 C P=1.0 MPa Intercooler N =1.68 MW Water for cooling t=20 C Q=21.1 kg/s Feed water Water for cooling G=35.0 kg/s t=20 C t=23.9 C G=4.76 kg/s P=0.6517 MPa t= 94.3 C P=1.0296 MPa LPC N=1.743 MW Flow diagram of HTR-10 GT
HTR-10 GT Parameters for HTR-10 with the gas turbine cycle Value POWER CONVERSION UNIT Thermal power transferred to PCU, MW Thermal power transferred to the gas-turbine cycle, MW Thermodynamic efficiency, % Gross efficiency (el.) of the RP gas-turbine part, % Total relative pressure loss, % Total relative helium leaks, % PCU mass, t PCU height, mm Water temperature at the PCU inlet, C 10.00 6.755 32.247 29.314 11.8 5.3 64 9100 20.0 REACTOR Temperature at the core inlet/outlet, C Pressure at the inlet/outlet, MPa Helium flow rate, kg/s 330/752.1 1.5312/1.5159 4.55
HTR-10 GT HTR-10 with He gas turbine cycle
Ideas and Comments about Possible Experiments on HTR-10 are welcome and appreciated!