IMPORTANT NUCLEAR INSTALLATION AND EQUIPMENT 1
Annual Report of HWRR in 2006
ZHANG Xing-wang
1 Operating time and released energy
In 2006, the Heavy Water Research Reactor(HWRR) has been safely operated for 3082h and the energy released was 884.6MW·d, with operating power level 6500-7300kW. The operation statistics of HWRR in 2006 is shown in Table1.
Table1 The operation data of HWRR in 2006
Month / Operating time/h / Energy released/(MW·d)4 / 173 / 50.4
5 / 434 / 126
6 / 476 / 138
7 / 452 / 131
8 / 418 / 111
9 / 256 / 74
10 / 465 / 136
11 / 11 / 3.2
12 / 397 / 115
2 Safety re-examination
From January to April, 2006, experts employed by National Nuclear Safety Administration(NNSA) have conducted safety re-examination on HWRR several times with detailed improving requirements of software and hardware. Then, HWRR section has accomplished all the items required by NNSA, including reinforcement of storage batteries, protection of power supply units, function extension of two spare safety rods and house keeping. At the same time, it also has completed the revision of HWRR Operation Quality Assurance Programme (Edition B)andHWRR Procedure Series (Edition B).
All improving projects of software and hardware on HWRR have passed examination of expert mission and been approved by NNSA, which granted all operational safety requirements had been met, and issued Operation Certificate of HWRR in April, 2006.
3 Scientific research, production and repair
1) Isotopes irradiated: 373 cans; NTD silicon irradiated: 4000 kg.
2) Nuclear Physics experiments such as neutron scattering and neutron diffraction have been conducted.
3) Irradiation of the second rig of special material has been successfully conducted.
4) 22 fuel assemblies have been refueled.
5) Driving devices of automatic regulating rod A and B have been repaired.
6) Both 47# and 48# emergency power generators have been repaired.
7) Heavy water pump C has been overhauled, the retaining valves at its outlet repaired.
8) Secondary coolant channels of main heat exchanger A and B and heat exchanger C have been cleaned out.
9) Connection tube of shield cooling system has been maintained.
10) Total 93kg heavy water has been supplemented to the core.
11) Personnel training on radiation protection, operation procedures and expertise has been fulfilled according to HWRR annual training plan.
4 Disposal of radioactive wastes
Gas wastes exhausted from stack:41Ar, 4.584×1014Bq; 3H, 10.23×1011Bq; Totalβ, 3.92×106 Bq; Solid wastes, 4.4m3; Liquid wastes,10m3.
5 Fuel assemblies
There are 69 fuel assemblies loaded in the core, 319 spent fuel assemblies stored in the spent fuel storage, 26 new fuel assemblies stored in the fresh fuel storage.
6 Operators working in HWRR
There are total 27 operators, including 12 shift leaders, 12 operators, 3 practice operators.
7 Visitors
More than 1000 visitors including foreigners visited HWRR in 2006.
8 Nuclear power services
Total 55 operators have been trained on HWRR in 2006, of which 27 are CARR operators, who have completed training, the other 28 are operators from Daya Bay Nuclear Power Plant, who have completed operation practice on HWRR .
9 Abnormal events
There are total 7 abnormal events occurred in 2006.
1) Loss of power of control cabinet for the second irradiation rig of special material，HWRR scrammed
May 4, 2006, the scram signal “Rig abnormal” was triggered by the control of the irradiation rig cabinet losing power supply, since insulation ageing of electricity wire used in control cabinet caused short circuit, all control rods inserted to the core, the reactor was shut down.
After the reactor was shutdown, corrective and preventive measures were established and implemented. The measures are: (1)To inspect all equipment and change aged components;(2)To normalize equipment placement and clear up unnecessary equipment.
2) Loss of external power, HWRR scrammed
In 2006, loss of external power occurred 5 times, all of which have been treated correctly, after external power recovered, the reactor was started again and operated at full power.
The main reasons for loss of external power are malfunction of converting station equipment, pole rupture of external power grid and voltage fluctuation caused by thunder and lighting.
3) Heavy water found between inner and external vessel
September 6, 2006, heavy water was found in the Room 26 between inner and external vessel. Examination and water sample analyses have been carried out several times, testing operation two times, the result shows that inner vessel leak can be excluded. Further analyses show that there are two possible points which might have caused heavy water appearing in the space between inner vessel and outer vessel, i.e. dispersion and accumulation of heavy water vapor and reversed flow of heavy water in the auxiliary systems caused by wrong operation.
All of 7 abnormal events were timely and correctly treated, thus no actual safety consequence on the reactor happened. They were also reported to the regulatory body within the requirement of Abnormal Event Reporting Programmer.
After each event, different corrective and preventive measures have been established and implemented. Furthermore, through the process of judgment, analysis, treatment and discussion of the events, operational experience, lessons, capabilities and awareness are accumulated so as to ensure the operational safety.
MNSR Annual Operation Report
ZHU Guo-sheng
Guided by the nuclear Safety roles，code and Standards of China，MNSR performed safe operation in 2006.The annual operation report of MNSR in 2006 is as follows.
1) Licensees are 4 persons.
2) Operation times of 2006: 19; Full power operation among them: 4.
3) Total operation hours: 132.48h; Equivalent hours for full power: 102.41 h.
4) Energy released is 2765.07kW·h.
5) Water guilty: Specific resistance is more than 3×105Ω·cm for reactor water;Specific resistanceis more than 2×105Ω·cm for pool water.
6) Electricity consumption is 17340 kW·h.
7) NAA Samples are 353 pcs.
8) Test:5 pcs of nuclear detectors.
9) Dosage:Within the dose limits.
(1) Persons are 16.
(2) Individual annual doserage is 0-0.11mSv.
(3) Total annual collective dosage is 7.8×10－1man·mSv.
(4) Average annual individual dose is 4.9×10－2man·mSv.
(5) Maximum annual individual dose is 1.1×10－1man·mSv.
HI-13 Tandem Accelerationin 2006
KAN Chao-xin, HU Yue-ming, BAO Yi-wen, FANHong-sheng
HI-13 tandem accelerator was running well in 2006.Because of the facilities installation and modulation for the injector upgrading from May to September ,this year the machine operated only 2 870 h, and provided beam time 2 300 h for more than 16 experiment users, the terminal voltage range was from 3 MV to 13MV.
1 The operation
In 2006, HI-13 tandem accelerator provided 15 kinds of ions and 2 300 h beam time.The distribution of beam time versus ion was shown in Fig. 1.
Fig.1 Distribution of beam time versus ion of HI-13
2 Maintenance and development
1)The tank was opened 7 times in 2006, besides replacing the stripper and normal maintenance the main work was dealing with some problems for the laddertron.
2) Finished the project for injector upgrading, after preparing for more than one year, we installed and modulated devices from May to September, all the specifications are very good.
3) R70° beam line developing work was carried through, the machine design, machining and others were finished, next year all the devices will be installed and adjusted.
4) SEE (Single Event Effects) branch beam line will be built based on R20° in two years, the mode selected, physical and mechanical design werefinished.
5)The installation and modulation of the speed selector for R50° beam line were finished.
6) The project for the accelerator radiation protection and safety technology development was started, all the work are carried on.
7)300 nuclear targets and 400 pieces of strip films wereprovidedto users, development of facilities for targets making began.
8) It was decided that the main accelerator vacuum system should be replace with no-oil vacuum pump system.
Operation and Status of 5SDH-2 Pelletron Accelerator
WANG Zhi-qiang, LUO Hai-long
The 5SDH-2 accelerator has been in use for ten years since it was introduced in 1996. Up to now all technical parameters retain the level when the machine was introduced. In the past years, we have been engaged in establishing mono-energetic neutron reference field. In the reference field the neutron dose meters and neutron detector were calibrated. The calibration services have been provided for Northwest Institute of Nuclear Technology and China Academy of Engineering Physics for a few years.
At present the pulsed upgrading and computer automation are in process for the accelerator, and this project will be finished in October, 2007. After the modification, the beam current will be adjusted by the computer and the information of the various parameters is restored in the computer. The main technical parameters are in the following:
1) Pulse repetition rate: 4, 2, 1, 0.5, 0.25, 0.125, and 0.062 5 MHz；
2) Pulsed width: ≤2 ns, adjustable；
3) Averaged beam current: 5-50μA, DC; 3-6 μA, pulsed .