Ongkharak Nuclear Research Center Project

Transcription

1 Ongkharak Nuclear Research Center Project Asst. Prof. Dr. Sunchai Nilsuwankosit 8 th Nuclear Energy Symposium Tokai University, Tokyo, Japan March 15-16, 2004 Short Summary As the research reactor employed at the main office of Thailand s Office of Atomics for Peace (OAP) is approaching its expected lifetime, the new research reactor is planned to be constructed as part of the Ongkharak Nuclear Research Center Project (ONRC) at the District of Ongkharak in Nakhonnayok Province, some 50 km from Bangkok on its northeastern part. The new research reactor is of General Atomic s TRIGA type. It has the maximum steady state power of 10 MW th. With this new reactor at its new location, the production of many radioisotopes to be used for the madical, the agricultural the industrial purposes is expected to be much larger in volume and with much higher efficiency. In addition, various researchs on nuclear technology and other analytical processes that requires the usage of the reactor are possible and also planned. The involvement of other government agencies and outside parties in these activities is also expected and welcome.

2 Ongkharak Nuclear Research Center Project Asst. Prof. Dr. Sunchai Nilsuwankosit 8 th Nuclear Energy Symposium Tokai University, Tokyo, Japan March 15-16, 2004 Thailand Profile on Nuclear Power In 1976 the Electricity Generating Authority of Thailand (EGAT) submitted a request for bidding on a nuclear power project to the government. The request was overruled due to political uncertainty, the public opposition and the prospect of using the indigenous petroleum resources. Still, the nuclear power had gained the positive perception from the public until the time of the Chernobyl accident. The impact from the accident undoubtedly caused a setback on the future of the energy in the country. Beside the safety concern, the substantial amount of the investment is also the additional issue that must be addressed. To introduce nuclear power into the national energy scene, energy and nuclear power planning was launched in Four government agencies, namely, the Office of Atomics for Peace, the National Economic and Social Development Board, the National Energy Administration and EGAT partook the job under the technical assistance of IAEA. Its objective was to quantify the future energy requirements consistent with both the national economic development plans and the expected share of electricity in the overall energy needs. The study then outlined an economically optimal electrical system expansion scheme including an assessment of the needs and role of nuclear power. Conclusion on the study was made in mid The study formulated a comprehensive power development plan up to year 2011 based upon the average GNP growth of 4-5 percent per annum. On this basis and with the assumptions that the cost of the nuclear plant was in the level of 1,200 $/kw and the coal price was 55 $/ton, one or two 900 MW nuclear units would be expected between 2000 and This was designed according to the demand level that was in the order of 10,000 20,000 MW per annum. Nonetheless, should its cost reach 1,400 $/kw, the nuclear power would be considered non-competitive and would be dropped off. Currently, the activities involving nuclear technology in Thailand are mainly governed by the Office of Atomics for Peace (OAP). The office was originally founded as the Office of Atomic Energy for Peace (OAEP) in 1961 under the Atomic Energy for Peace Act B.E

3 In 2002, as the Minitry Act B.E came into effect, its current title was adopted and became an agency under the Ministry of Science, Technology and Environment. The organization of OAP is as illustrated Figure 1. OAP 1. Office of the Secretary 2. Bureau of Atomic Energy Administration 3. Bureau of Radiation Safety Regulation 4. Bureau of Nuclear Safety Regulation 5. Bureau of Technical Support for Safety Regulation Figure 1. Organizing Chart for OAP Thai Research Reactor-1/Modification 1 (TRR-1/M1) Currently, OAP employs one research reactor. Its site is at the location of its office in Bangkok. The construction of the reactor was begun in The reactor was finished and had reached its first criticality at 06:32 PM on 27 th October In 1973, the reactor had undergone an extensive modification. Due to this modification, the reactor was titled Thai Research Reactor-1/Modification 1 (TRR-1/M1). The reactor is as roughly shown in Figure 1. Figure 2. Thailand Research Reactor-1/Modification 1 (TRR-1/M1) TRR-1/M1 was designed and constructed by General Atomics (GA) and is known as the TRIGA Mark III type. It has the steady state power output of 2 MW th and is capable of generating upto 2,000 MW th for the period of 10.5 ms in pulsing mode.

4 Figure 3. Reactor Building of TRR-1/M1 The building where the reactor TRR-1/M1 is contained is a five-storied building. It also houses a number of laboratries that make use of the neutron fluxes provided by the reactor. Figure 3 illustrates this building and the control room for TRR-1/M1. In general, TRR-1/M1 is used to produce various radioisotopes for the medical and argicultural purposes. It is also used for the analysis of a sample by the Neutron Activation Analysis (ANA) and for Non-Destructive Testing (NDT). TRR-1/M1 is also the platform that provides the training for the personnel in nuclear engineering. In addition, OAP also cooperates with various other government agencies and companies that require the usage of TRR-1/M1 in their researchs. Ongkharak Nuclear Research Center Project As TRR-1/M1 has been in use since 1965, it is quickly approaching its expected lifetime and, otherwise, will soon have to be de-commissioned. Upon considering that the city of Bangkok has expanded during the past 30 years such that the office of OAP and its facilities, TRR-1/M1 included, are now located in the populated area of the city and is relatively close to the international airport, the government of Thailand decided in 1989 that OAP and its facilities should be re-located. Due to this decision, the Ongkharak Nuclear Research Center Project (ONRC) was originated. With the co-operation with the International Atomic Energy Agency (IAEA), a piece of land in the district of Ongkharak in the province of Nakhonnayok, about 50 km north-east of Bangkok, was chosen as the location for ONRC (hence its name). For ONRC, the new and larger research reactor is also to be constructed. Currently, the on-site progress of ONRC is mostly complete, except for the construction of the new research reactor. As Thailand s Nuclear Regulartory Committee recently issued the construction permit for the new research reactor, it is expected that its construction will very soon begin.

5 Figure 4. Locations of OAP and ONRC Thai Research Reacrtor-2 (TRR-2) The new research reactor is also the TRIGA type by GA. The reactor is named Thai Research Reactor-2 (TRR-2). It has the maximum steady state output power of 10 MW th with the sizes of the neutron fluxes in the order of neutrons/cm 2 s. The design of TRR-2 is roughly presented in Figure 5. For other information regarding TRR-2, the reader is asked to consult Table 1. Figure 5. TRR-2, Reactor Pool

6 Figure 6. TRR-2, Reactor Structure Figure 7. TRR-2, Reactor s Cross-Section

7 Table 1. Information regarding TRR-2 Type of Reactor Pool s dimension Fuel (29 bundles, 4 4 pencils/bundle) Reactivity Control System Safety Criteria Maximum steady state power Neutron Flux Irradiation Facilities Neutron Beams TRIGA Open cylindrical pool lined with stainless steel Depth 10 m, Diamter 4 m UErZrH 1.6 (20 w / o 235 U) Length mm, Diameter mm (fuel pencil) B 4 C 4 electromagnetic controlled annular control rods Limited neutron flux Limited power density Limited fuel temperature Limited primary flow rate Limited difference in flow rate for in and out flow on the primary side Limited lower water level 10 MW th More than neutrons/cm 2 s In-Core High Thermal Neutron Flux Tubes ( 192 Ir production) Fast Neutron Flux Tubes Out-Core (Reflector Zone) 21 tubes (Diameter 25 mm) 5 tubes (Diameter 38 mm) Pneumatic System 2 sets (PN1, PN2) with the delivery time < 5 s 1 set (PN3) with the delivery time < 0.5 s Silicon Irradiation tubes (Reflector Zone) 3 tubes (Diameter 203 mm) NB1 for research involving neutron diffraction NB2 for neutron radiography NB3 for prompt gamma neutron activation analysis NB4 for Boron neutron capture therapy NB5 and NB6 are available for possible future used

8 Possible Usage of TRR-2 TRR-2 was designed with the following plan for its usage. 1. Radioisotope production o TRR-2 is to be used in the production of 125 I, 131 I, 99 Tc, 32 P and 192 Ir. These isotopes are mainly used for the medical, argricultural and industrial purposes. 2. Treatment of Brain Tumor o By injecting boron into the brain tissue, the absorption of neutrons by boron will result in the alpha and the gamma decays, which will irradiate and kill the tumored cells. 3. Gems Irradiation o The process of neutron absorption can enhance some relatively low value gems. Currently, the neutron irradiation on topaz is being considered. 4. Silicon Irradition o By neutron irrdiation, some of the silicon nuclei that have absorbed neutrons will be transformed into phosphorus. In effect, the impurity is introduced into the irradiated sample. The result is the production of the semi-conductive materials that can be used in the electronics industry. 5. Neutron Radiography o In testing the finished products, it is quite often necessary that the sample must not be damaged. In such case, the image obtained with the neutron radiography can be very useful for this purpose. 6. Material Analysis by Neutron Scattering o The scattering of neutrons by the nuclei in the samples can give the valuable information regarding the arrangement of the nuclei in the samples. This information is then used to determine the properties of the materials. 7. Neutron Activation Analysis o To determine the composition of a sample, the process of neutron activation can be very useful for this purpose. Summary The construction of TRR-2 is the major task of ONRC. Not only it is the main facility of ONRC where the research and all other activities by OAP take place, it will likely be the

9 only nuclear reactor in Thailand still in operation when its construction is finished. As a result, TRR-2 will also be the center of the study in the field of nuclear technology in Thailand. With all the supporting systems provided by TRR-2, various research activities will be open for the parties outside OAP and that the co-operations between such parties and OAP should be possible. In addition, as OAP is changing its role as the regulator to an operator, TRR-2 will be its first responsibility as a sole operator of a nuclear research reactor. The operation of TRR-2 by OAP should provide a test case for the function of the newly created Nuclear Regulatory Committee. The operation of TRR-2 and the regulatory action by OAP and the Nuclear Regulatory Committee are the indicators that describe Thailand s readiness in fully adopting the nuclear industry in the near future. References 1. Office of Atomics for Peace, 2. Thawee Siri-udomrat, 2nd ASIAN SPECIALIST MEETING ON FUTURE SMALL- SIZED LWR DEVELOPMENT, November 26-27, 2003, Hanoi, Vietnam 3. General Atomics, Preliminary Safety Analysis Report for the 10-MW ONRC TRIGA Reactor, June 1998