The present invention relates to a nuclear fuel arrangement in fuel pools for nuclear power plant, and more particularly, to a fuel arrangement for a fuel pool capable of arranging nuclear fuel bundles in a rugged formation of different heights for reducing flux and effective multiplication factor of neutrons and thus causing the nuclear critical safety of the fuel pool to be enhanced
The production of greenhouse gases and potential climate change is a problem of global proportion. Man's use of energy, especially in industrial activity with fossil fuel burning that emits gases containing carbon dioxide, is thought by most experts to be the major contributor to greenhouse effect responsible for climate change. Thus, people all over the world are searching for alternative energies as they are aiming to live in a greener and more energy efficient lives. Among those available alternative energies, as nuclear power can provide energy in a manner which contributes very little to the greenhouse effect, it will necessarily play a greater role in our lives in the future. However, there are still many details and operations in the nuclear power generation required to be improved for safety.
Normally, in most nuclear power plants, the fuel bundles as well as the spent fuel bundles are stored in fuel pools whereas the arrangement of the fuel bundles in the fuel pools is regulated for preventing those fuel bundle from being placed too close to each other and thus causing critical safety problem. However, for increasing the amount of fuel bundles capable of being stored in a fuel pool while preventing the critical safety problem from happening as the distance between any two neighboring fuel bundles may be too close, boron pieces or other neutron-absorbing materials are used in the fuel pool for reducing the flux of neutrons. Alternatively, the flux of neutrons can be reduced by arranging the fuel bundles in the fuel pools at positions according to their extents of burn-up. However, the use of boron piece will increase cost and the position arrangement/adjustment may be erroneous by human error, that both methods for increasing the amount of fuel bundles capable of being stored in a fuel pool still have shortcomings require to be improved.
For improving nuclear safety, the design of the aforesaid nuclear fuel arrangement must take the critical safety problem relating to neutrons in nuclear fuel as well as heat dissipating problem into consideration. That is, the nuclear fuel arrangement should be designed for arranging the fuel bundles in a formation conforming to international regulations. Please refer to
In view of the disadvantages of prior art, the object of the present invention is to provide a nuclear fuel arrangement in fuel pools for nuclear power plant capable of arranging the nuclear fuel bundles in the fuel pools in an improved formation for narrowing the distances between any two nuclear fuel bundles in the formation while meeting the optical safety requirement. In an embodiment, the present invention provides a nuclear fuel arrangement capable of arranging the nuclear fuel bundles in a rugged formation of different heights for reducing flux and effective multiplication factor of neutrons and thus causing the nuclear critical safety of the dry storage canister to be enhanced.
To achieve the above object, the present invention provides a nuclear fuel arrangement in fuel pools for nuclear power plant, which comprises: a plurality of nuclear fuel bundles, being arranged in a tight formation; a pool partition framework, formed with a plurality of grids for storing the plural nuclear fuel bundles; wherein the pool partition frame has a plurality of blocks of different heights disposed at the bottoms of their corresponding grids to be used for enabling any neighboring nuclear fuel bundles in the tight formation to be ruggedly arranged with different heights.
Preferably, the blocks in the odd-numbered rows or columns of the pool partition framework are formed of a same specific height for aligning the nuclear fuel bundles in the odd-numbered rows or columns to each other at the same height while the blocks in the even-numbered rows or columns of the pool partition framework are formed of another same specific height for aligning the nuclear fuel bundles in the even-numbered rows or columns to each other at the same height.
Preferably, the plural blocks are substantially a grouping of high blocks and low blocks arranged in a chessboard-like array in a manner that any one high block is surrounded by low blocks and any one low block is surrounded by high blocks.
Preferably, the height difference between neighboring nuclear fuel bundles is ranged between 3 inches to 12 inches.
Further scope of applicability of the present application will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein:
For your esteemed members of reviewing committee to further understand and recognize the fulfilled functions and structural characteristics of the invention, several exemplary embodiments cooperating with detailed description are presented as the follows.
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The following description is related to critical condition in neutron behavior for illustrating the aforesaid rugged formation 3 with height difference Δh can achieve higher nuclear critical safety. The effective multiplication factor (keff), which is defined as the ratio of the neutrons produced by fission in one generation to the number of neutrons in the preceding generation. So, the value of keff for a self-sustaining chain reaction of fissions, where the neutron population is neither increasing nor decreasing, is one. The condition where the neutron chain reaction is self-sustaining and the neutron population is neither increasing nor decreasing is referred to as the critical condition and can be expressed by the simple equation keff=1. On the other hand, when keff<1, it is referred as subcritical condition whereas flux decreases each generation; and when keff>1, it is referred as supercritical condition whereas the neutron flux increases each generation indicating that the nuclear reaction might not be able to stop. Therefore, for achieving nuclear safety, the value of keff should be restricted. Moreover, as keff is closely related to the density of neutrons being produced in the fission, the arranging of the fuel bundle in the rugged formation of height difference is able to cause the density of neutrons distributed on the top and bottom of the storage canister to drop and thus cause the value of keff to reduce so as to enhance the nuclear safety.
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With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Number | Date | Country | Kind |
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098117678 | May 2009 | TW | national |