JPS6367598A - Method of washing spent fuel aggregate - Google Patents
Method of washing spent fuel aggregateInfo
- Publication number
- JPS6367598A JPS6367598A JP21303486A JP21303486A JPS6367598A JP S6367598 A JPS6367598 A JP S6367598A JP 21303486 A JP21303486 A JP 21303486A JP 21303486 A JP21303486 A JP 21303486A JP S6367598 A JPS6367598 A JP S6367598A
- Authority
- JP
- Japan
- Prior art keywords
- cleaning
- spent fuel
- fuel assembly
- tank
- liquid metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002915 spent fuel radioactive waste Substances 0.000 title claims description 55
- 238000000034 method Methods 0.000 title claims description 35
- 238000005406 washing Methods 0.000 title description 3
- 238000004140 cleaning Methods 0.000 claims description 91
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 29
- 229910052708 sodium Inorganic materials 0.000 claims description 29
- 239000011734 sodium Substances 0.000 claims description 29
- 239000007789 gas Substances 0.000 claims description 25
- 238000000429 assembly Methods 0.000 claims description 20
- 230000000712 assembly Effects 0.000 claims description 20
- 229910001338 liquidmetal Inorganic materials 0.000 claims description 16
- 239000000446 fuel Substances 0.000 claims description 11
- 239000010795 gaseous waste Substances 0.000 claims description 7
- 238000011084 recovery Methods 0.000 claims description 6
- 230000006837 decompression Effects 0.000 claims description 5
- 238000001704 evaporation Methods 0.000 claims description 5
- 239000011261 inert gas Substances 0.000 claims description 5
- 239000002826 coolant Substances 0.000 claims description 3
- 230000008018 melting Effects 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims description 2
- 229920006395 saturated elastomer Polymers 0.000 claims description 2
- 239000007788 liquid Substances 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 230000002285 radioactive effect Effects 0.000 description 5
- 239000003595 mist Substances 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 3
- 239000002901 radioactive waste Substances 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- 238000011109 contamination Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- 239000002912 waste gas Substances 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000002927 high level radioactive waste Substances 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Landscapes
- Processing Of Solid Wastes (AREA)
- Solid Fuels And Fuel-Associated Substances (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
この発明は、１次冷却材としてナトリウム等の液体金属
を使用する高速増殖炉の使用済燃料集合体を対象とした
使用済燃料集合体の洗浄方法に関する。The present invention relates to a method for cleaning spent fuel assemblies of fast breeder reactors that use liquid metal such as sodium as a primary coolant.
周知のように頭記した原子炉から取出した使用済燃料集
合体は、燃料貯蔵プール内に保管する前段階の工程で燃
料集合体に付着しているナトリウム等の液体金属を洗浄
することが一触に行われている。
この場合の使用済燃料集合体の洗浄法として、従来より
使用済燃料集合体を洗浄槽内に収容した状態で使用済燃
料集合体に蒸気を含む湿潤ガスを吹付け、さらに水で洗
浄した後に、燃料集合体を温風等で乾燥させる蒸気−水
洗浄法が知られている。しかしてかかる蒸気−水洗浄法
は１本の使用済燃料集合体の洗浄に１．５時間にも及ぶ
長時間を要する他、さらに洗浄に伴って使用済燃料集合
体１本当たりで約１．５トンにも及ぶ放射性クランド。
放射性腐食生成物等を含む多量の放射性洗浄廃液が発生
するために、廃液処理系設備の大形化、および放射能汚
染の増加などの廃棄物処理上での厄介な問題がある。As is well known, the spent fuel assemblies taken out from the above-mentioned nuclear reactor must be cleaned of liquid metals such as sodium adhering to them in the process before being stored in the fuel storage pool. It is done to the touch. In this case, the conventional method for cleaning spent fuel assemblies is to blow wet gas containing steam onto the spent fuel assemblies while they are housed in a cleaning tank, and then wash the spent fuel assemblies with water. A steam-water cleaning method is known in which fuel assemblies are dried with hot air or the like. However, such a steam-water cleaning method requires a long time of up to 1.5 hours to clean one spent fuel assembly. A radioactive clan weighing up to 5 tons. Since a large amount of radioactive cleaning waste liquid containing radioactive corrosion products is generated, there are troublesome problems in waste treatment, such as an increase in the size of waste liquid treatment equipment and an increase in radioactive contamination.
この発明は上記の点にかんがみなされたものであり、前
記した従来の洗浄方法の難点を解消し、放射性廃液の発
生無しに乾式で使用済燃料集合体に付着している液体金
属を短時間で効率よく洗浄できるようにした従来に無い
新規な使用済燃料集合体の洗浄方法を提供することを目
的とする。This invention was developed in consideration of the above points, and it solves the difficulties of the conventional cleaning methods described above, and allows the liquid metal adhering to spent fuel assemblies to be removed dryly in a short period of time without generating radioactive waste liquid. It is an object of the present invention to provide a new and unprecedented method for cleaning spent fuel assemblies that enables efficient cleaning.
上記目的を達成するために、この発明は使用済燃料集合
体を収容する洗浄槽と、該洗浄槽内に収容する使用済燃
料集合体を昇温する予熱手段と、洗浄槽内を排気減圧す
る減圧手段とを備え、予熱手段により使用済燃料集合体
を所定温度まで昇温する予熱工程と、予熱された使用済
燃料集合体を洗浄槽内に収容した状態で減圧手段により
洗浄槽内を減圧する減圧工程とを経て、燃料集合体に付
着している液体金属を蒸発させて洗浄することにより、
燃料集合体に付着している液体金属を蒸発させて洗浄す
るようにしたものであり、この洗浄方式により水蒸気、
水等を使用しないので洗浄に伴う多量の放射性廃液の発
生無しに、僅かな量の排、ガスを処理するだけで使用済
燃料集合体を効率よく洗浄することが可能となる。In order to achieve the above object, the present invention includes a cleaning tank for accommodating spent fuel assemblies, a preheating means for increasing the temperature of the spent fuel assemblies accommodated in the cleaning tank, and a means for evacuation and depressurization of the inside of the cleaning tank. a preheating step in which the spent fuel assembly is heated to a predetermined temperature by the preheating means, and a pressure reduction step in the cleaning tank with the preheated spent fuel assembly accommodated in the cleaning tank. By evaporating and cleaning the liquid metal adhering to the fuel assembly,
This cleaning method evaporates and cleans the liquid metal adhering to the fuel assembly, and this cleaning method removes water vapor,
Since no water or the like is used, spent fuel assemblies can be efficiently cleaned by only treating a small amount of waste gas and waste gas without generating a large amount of radioactive waste liquid associated with cleaning.
図は１次冷却材としてナトリウムを使用した高速増殖炉
を対象としたこの発明の実施例による使用済燃料集合体
の洗浄設備の系統図を示すものであり、図において１は
頂部にドアバルブ２を装備した洗浄槽、３が洗浄槽内に
収容された使用済燃料集合体である。
ここで前記洗浄槽１に対しては、プロア４．ガス加熱器
５．ガス冷却器６．ベーパトラップ７等を具備して洗浄
槽１との間に接続配管したガス循環ライン８、および該
ガス循環ライン８に接続された例えばアルゴンガスの不
活性ガス源９を含めた使用済燃料集合体の予熱手段と、
洗浄槽１より真空タンク１０．真空ポンプ１１．ベーパ
トラップ１２等を経て気体廃棄物処理系１３に通じる減
圧排気ライン１４として成る減圧手段が装備されている
。さらに洗浄槽１および真空タンク１０にはその底部よ
り引出して、ナトリウムのドレンタンク１５．ナトリウ
ム送液ポンプ１６を経てナトリウム回収系１７に通じる
ナトリウムのドレンライン１８が接続配管されている。
なお１９〜２９は前記したガス循環ライン。
減圧排気ライン、ドレンラインの系内に介挿した開閉バ
ルブ、３０．３１は洗浄槽１．真空タンク１０にそれぞ
れ配備したナトリウム溶解用の加熱ヒータである。
次に上記構成の洗浄設備による使用済燃料集合体の洗浄
操作の手順に付いて説明する。まず原子炉より取り出し
た使用済燃料集合体３をドアバルブ２を通じて洗浄槽１
内に収容する。ここでバルブ１９〜２１を開放し、不活
性ガス源９より所定量のアルゴンガスを系内に導入し、
さらにプロア４゜ガス加熱器５を始動して加熱されたガ
スを洗浄槽！内に循環送流し、崩壊熱を発生する燃料ピ
ン。
および燃料ピン以外の非発熱部を含む使用済燃料集合体
３の全長域をナトリウムの溶融温度以上の所定の予熱温
度（約３３０℃以上で好ましくは４５０〜５５０℃程度
）まで加熱昇温させる。なおこの予熱工程の段階で使用
済燃料集合体３の表面、内部に固化して付着堆積してい
るナトリウムは融解するようになってその一部は洗浄槽
内に流下するとともに、蒸発して洗浄槽内に浮遊するナ
トリウム蒸気、ミストはアルゴンガスに同伴してガス循
環ライン中のベーパトラップ７に吸着除去される。
またこの予熱工程の過程で使用済燃料集合体３の温度、
特に崩壊熱を発生する燃料ピンの表面温度が許容温度で
ある６５０℃に達するようになった場合には、一時的に
ガス循環ライン８のガス冷却器６を始動して循環ガス温
度を下げ、使用済燃料集合体３を所定の予熱温度に維持
させるように温度調節を行う、一方、この予熱工程を行
っている期間にパルプ２２．２３を閉じたまま真空ポン
プ１１を始動して真空タンク１０を減圧して置り。
ここで前記した予熱工程により使用済燃料集合体３が所
定の予熱温度に到達した時点でブロア４゜ガス加熱器５
を停止し、かつパルプ１９．２０を閉じ、しかる後にま
ず真空タンク１０に通じるバルブ２２を開放して洗浄槽
１の内部を急激に減圧させる。続いてバルブ２２を閉じ
て真空タンク１０との間を切離した後に、バルブ２３を
開放して真空ポンプ１１により洗浄槽ｌ内をさらに真空
引きし、洗浄槽内の内圧がその温度に対するナトリウム
飽和蒸気圧以下。
例えば４〜１０Ｔｏｒｒ程度となるように減圧排気させ
る。この減圧工程により使用済燃料集合体３の表面、内
部に付着したいたナトリウムは蒸発促進され、ナトリウ
ム蒸気、ミストの形で使用済燃料集合体３より洗浄除去
されるようになる。なおこの過程で生じたナトリウム蒸
気、ミストは大半が洗浄ｉ１．および真空タンク１ｏの
内部に移行して付着し、残りの浮遊蒸気、ミストは排ガ
スに同伴して減圧排気ライン１４中のペーパートラップ
１２に吸着除去され、洗浄槽１の内容積に見合う量の排
ガスのみが気体廃棄物処理系１３に送出されて処理され
る。
さらに上記の洗浄操作を必要により数回繰り返して行い
、使用済燃料集合体３を充分に洗浄して一連の洗浄工程
が終了する。また前記の洗浄に伴って洗浄槽ｌ、真空タ
ンク１ｏに蒸着したナトリウムは、洗浄槽１真空タンク
に装備した加熱ヒータ３０、３１．および使用済燃料集
合体自身の崩壊発熱により約３００℃程度に加熱してナ
トリウムを溶融させた上で、パルプ２６．２７を開放し
てナトリウムをドレンタンク１５へ排出し、ここからナ
トリウム送液ポンプ１６によりナトリウム回収系１７に
送出して回収される。
なお前記洗浄方法に付いて発明者の行った基礎実験の結
果によれば、試料の表面に付着させたナトリウムは試料
表面温度約３３０ｔ、洗浄槽内圧力１０Ｔｏｒｒで白煙
の発生して蒸発するのが観察され、またこの場合に試料
の付着ナトリウムが蒸発除去されるに要する時間は、試
料温度が高い程、かっ洗浄槽内の圧力が低い程短くなる
傾向を示すことが確認された。また洗浄前と洗浄後とで
試料表面に付着したナトリウム量に付いて測定した処、
洗浄前に２．２５ｍｇ／−であったナトリウムは洗浄後
にナトリウム残留量が０．０３ ａ＋ｇ／ ａＪまで減
少することが確認された。
さらに実際の使用済燃料集合体を対象とした洗浄操作で
も、完配の洗浄方式における予熱工程。
減圧工程を含めた１サイクル分の洗浄操作時間は約２０
分程度、したがって１本の使用済燃料集合体に付いて３
回の洗浄サイクルを繰り返し行っても洗浄所要時間は約
１時間で済み、従来の蒸気−水洗浄方式の１．５時間に
比べて大幅に洗浄時間の短縮化が図れるようになる。し
がち洗浄の際に蒸気。
水等を一切使用しないので、従来方式のように洗浄に伴
う多量の高レベルな放射性廃液の発生がなく、僅かな量
の排ガスを気体廃棄物処理系で処理するのみで済み、こ
れにより洗浄設備の顛略、小形化と併せて放射能汚染も
良好に抑えることができるようになる。
なお図示実施例では、使用済燃料集合体の予熱手段とし
て、使用済燃料集合体を洗浄槽内に収容した状態で加熱
した不活性ガスを洗浄槽内に送り込むガス加熱式のもの
を示したが、これ以外の予熱方法として、例えば洗浄槽
へ収容する以前の段階で使用済燃料集合体を加熱昇温し
たナトリウム内に浸漬することにより使用済燃料集合体
全体を所定の予熱温度まで昇温させ、続いて予熱済みの
使用済燃料集合体を洗浄槽内に収容し、減圧工程を経て
洗浄するようにすることも可能である。The figure shows a system diagram of a spent fuel assembly cleaning facility according to an embodiment of the present invention for a fast breeder reactor that uses sodium as the primary coolant. The equipped cleaning tank 3 is a spent fuel assembly housed in the cleaning tank. Here, for the cleaning tank 1, Proa 4. Gas heater5. Gas cooler6. A spent fuel assembly including a gas circulation line 8 equipped with a vapor trap 7 and the like and connected to the cleaning tank 1, and an inert gas source 9, such as argon gas, connected to the gas circulation line 8. a preheating means,
From the cleaning tank 1 to the vacuum tank 10. Vacuum pump 11. A decompression means is provided in the form of a decompression exhaust line 14 leading to the gaseous waste treatment system 13 via a vapor trap 12 or the like. Furthermore, a sodium drain tank 15. is drawn out from the bottom of the cleaning tank 1 and the vacuum tank 10. A sodium drain line 18 communicating with a sodium recovery system 17 via a sodium liquid feeding pump 16 is connected thereto. Note that 19 to 29 are the gas circulation lines described above. The opening/closing valve 30.31 is inserted into the vacuum exhaust line and drain line system, and 30.31 is the cleaning tank 1. These are heaters for dissolving sodium installed in each vacuum tank 10. Next, the procedure for cleaning spent fuel assemblies using the cleaning equipment configured as described above will be explained. First, the spent fuel assembly 3 taken out from the reactor is passed through the door valve 2 into the cleaning tank 1.
to be contained within. Here, the valves 19 to 21 are opened, and a predetermined amount of argon gas is introduced into the system from the inert gas source 9.
Furthermore, start the Proa 4° gas heater 5 and pour the heated gas into the cleaning tank! A fuel pin that circulates inside the fuel pin and generates decay heat. The entire length of the spent fuel assembly 3, including non-heat generating parts other than the fuel pins, is heated to a predetermined preheating temperature that is higher than the melting temperature of sodium (approximately 330° C. or higher, preferably about 450 to 550° C.). In addition, during this preheating process, the sodium that has solidified and deposited on the surface and inside of the spent fuel assembly 3 begins to melt, and a part of it flows down into the cleaning tank and evaporates to be cleaned. Sodium vapor and mist floating in the tank are adsorbed and removed by the vapor trap 7 in the gas circulation line along with the argon gas. Also, during this preheating process, the temperature of the spent fuel assembly 3,
In particular, when the surface temperature of the fuel pin that generates decay heat reaches the permissible temperature of 650°C, the gas cooler 6 of the gas circulation line 8 is temporarily started to lower the circulating gas temperature. The temperature is adjusted to maintain the spent fuel assembly 3 at a predetermined preheating temperature. Meanwhile, during the preheating process, the vacuum pump 11 is started with the pulp 22, 23 closed and the vacuum tank 10 is heated. Reduce the pressure and set it aside. Here, when the spent fuel assembly 3 reaches a predetermined preheating temperature through the preheating process described above, the blower 4° gas heater 5
is stopped, the pulps 19 and 20 are closed, and then the valve 22 communicating with the vacuum tank 10 is first opened to rapidly reduce the pressure inside the cleaning tank 1. Subsequently, after closing the valve 22 and disconnecting it from the vacuum tank 10, the valve 23 is opened and the inside of the cleaning tank 1 is further evacuated by the vacuum pump 11, so that the internal pressure in the cleaning tank becomes sodium saturated vapor at that temperature. Below pressure. For example, the pressure is evacuated to about 4 to 10 Torr. This depressurization step promotes evaporation of the sodium adhering to the surface and inside of the spent fuel assembly 3, and the spent fuel assembly 3 is cleaned and removed in the form of sodium vapor and mist. Note that most of the sodium vapor and mist generated in this process are from the cleaning i1. The remaining floating vapor and mist are adsorbed and removed by the paper trap 12 in the vacuum exhaust line 14 along with the exhaust gas, and the exhaust gas is removed in an amount corresponding to the internal volume of the cleaning tank 1. Only the gaseous waste is sent to the gaseous waste treatment system 13 for treatment. Further, the above cleaning operation is repeated several times as necessary, and the spent fuel assembly 3 is thoroughly cleaned, and the series of cleaning steps is completed. Also, the sodium deposited in the cleaning tank 1 and the vacuum tank 1o due to the above-mentioned cleaning is transferred to the heaters 30, 31. Then, the spent fuel assembly is heated to about 300°C by the heat generated by its own collapse to melt the sodium, and then the pulp 26, 27 is opened and the sodium is discharged to the drain tank 15, from which the sodium liquid feeding pump 16 to the sodium recovery system 17 for recovery. According to the results of basic experiments conducted by the inventor regarding the above-mentioned cleaning method, the sodium deposited on the surface of the sample evaporates with the generation of white smoke at a sample surface temperature of approximately 330 tons and a cleaning tank pressure of 10 Torr. was observed, and it was also confirmed that in this case, the time required for the adhering sodium on the sample to be removed by evaporation tends to be shorter as the sample temperature is higher and the pressure in the cleaning tank is lower. We also measured the amount of sodium attached to the sample surface before and after cleaning.
It was confirmed that the residual amount of sodium, which was 2.25 mg/- before washing, decreased to 0.03 a+g/aJ after washing. Furthermore, even in actual cleaning operations for spent fuel assemblies, the preheating process is used in a complete cleaning method. The cleaning operation time for one cycle including the pressure reduction step is approximately 20 minutes.
3 minutes per spent fuel assembly.
Even if multiple cleaning cycles are repeated, the cleaning time is only about 1 hour, which is much shorter than the 1.5 hours of the conventional steam-water cleaning method. Steam when cleaning. Since no water is used, there is no generation of large amounts of high-level radioactive waste fluids associated with cleaning, as is the case with conventional methods, and only a small amount of exhaust gas needs to be treated in the gaseous waste treatment system. In addition to this technology and miniaturization, radioactive contamination can also be effectively suppressed. In the illustrated embodiment, the spent fuel assembly preheating means is a gas heating type in which heated inert gas is sent into the cleaning tank while the spent fuel assembly is accommodated in the cleaning tank. As another preheating method, for example, the spent fuel assembly is heated to a predetermined preheating temperature by immersing the spent fuel assembly in heated sodium prior to storing it in a cleaning tank. It is also possible to subsequently accommodate the preheated spent fuel assembly in a cleaning tank and wash it through a decompression process.
以上述べたようにこの発明によれば、使用済燃料集合体
を収容する洗浄槽と、該洗浄槽内に収容する使用済燃料
集合体を昇温する予熱手段と、洗浄槽内を排気減圧する
減圧手段とを備え、予熱手段により使用済燃料集合体を
所定温度まで昇温する予熱工程と、予熱された使用済燃
料集合体を洗浄槽内に収容した状態で減圧手段により洗
浄槽内を減圧する減圧工程とを経て、燃料集合体に付着
している液体金属を蒸発させて洗浄するようにしたこと
により、従来の水蒸気−水洗浄方式と比べて洗浄に伴う
多量の放射性廃液の発生が無く、僅かな気体廃棄物を処
理するのみで済み、しがも節易な洗浄設備と短時間での
洗浄操作で使用済燃料集合体に付着しているナトリウム
等の液体金属を効率よく洗浄することができる。As described above, according to the present invention, there is provided a cleaning tank for accommodating spent fuel assemblies, a preheating means for increasing the temperature of the spent fuel assemblies accommodated in the cleaning tank, and a means for evacuation and depressurization of the inside of the cleaning tank. a preheating step in which the spent fuel assembly is heated to a predetermined temperature by the preheating means, and a pressure reduction step in the cleaning tank with the preheated spent fuel assembly accommodated in the cleaning tank. By evaporating and cleaning the liquid metal adhering to the fuel assembly through a depressurization process, there is no generation of a large amount of radioactive waste liquid during cleaning compared to the conventional steam-water cleaning method. , only a small amount of gaseous waste needs to be processed, and liquid metals such as sodium adhering to spent fuel assemblies can be efficiently cleaned using simple cleaning equipment and cleaning operations in a short time. Can be done.
図はこの発明の実施例による洗浄設備の系統図である０
図において、
１：洗浄槽、３：使用済燃料集合体、４ニブロア、５：
ガス加熱器、８：ガス循環ライン、９：不活性ガス源、
１０：真空タンク、１１：真空ポンプ、１３：気体廃棄
物処理系、１４；減圧排気ライン、１５；ドレンタンク
、１６：ナトリウム送液ポンプ、１７：ナトリウム回収
系、１８：ドレンライン。The figure is a system diagram of cleaning equipment according to an embodiment of the present invention.
In the figure, 1: cleaning tank, 3: spent fuel assembly, 4 nib blower, 5:
gas heater, 8: gas circulation line, 9: inert gas source,
10: Vacuum tank, 11: Vacuum pump, 13: Gaseous waste treatment system, 14: Decompression exhaust line, 15: Drain tank, 16: Sodium liquid feed pump, 17: Sodium recovery system, 18: Drain line.
Claims (1)
の使用済燃料集合体の洗浄方法であって、使用済燃料集
合体を収容する洗浄槽と、該洗浄槽内に収容する使用済
燃料集合体を昇温する予熱手段と、洗浄槽内を排気減圧
する減圧手段とを備え、予熱手段により使用済燃料集合
体を所定温度まで昇温する予熱工程と、予熱された使用
済燃料集合体を洗浄槽内に収容した状態で減圧手段によ
り洗浄槽内を減圧する減圧工程とを経て、燃料集合体に
付着している液体金属を蒸発させて洗浄することを特徴
とする使用済燃料集合体の洗浄方法。 ２）特許請求の範囲第１項記載の洗浄方法において、予
熱工程で使用済燃料集合体を液体金属の溶融温度以上に
昇温し、減圧工程では洗浄槽内圧力を前記予熱温度に対
する液体金属の飽和蒸気圧以下に減圧することを特徴と
する使用済燃料集合体の洗浄方法。 ３）特許請求の範囲第１項記載の洗浄方法において、予
熱手段がブロア、ガス加熱器等を具備して洗浄槽に接続
し、不活性ガス源から供給されたガスを加熱して洗浄槽
内との間で循環通流させるガス循環ラインであることを
特徴とする使用済燃料集合体の洗浄方法。 ４）特許請求の範囲第１項記載の洗浄方法において、減
圧手段が真空タンク、真空ポンプ等を具備して洗浄槽と
気体廃棄物処理系との間に接続した減圧排気ラインであ
ることを特徴とする使用済燃料集合体の洗浄方法。 ５）特許請求の範囲第１項記載の洗浄方法において、洗
浄槽に対し、使用済燃料集合体の洗浄に伴って使用済燃
料集合体より除去された洗浄槽内の液体金属を系外に排
除、回収する液体金属ドレンラインが接続されているこ
とを特徴とする使用済燃料集合体の洗浄方法。 ６）特許請求の範囲第５項記載の洗浄方法において、液
体金属ドレンラインが洗浄槽の底部よりドレンタンク、
液体金属の送液ポンプを経て液体金属回収系に接続され
ていることを特徴とする使用済燃料集合体の洗浄方法。[Scope of Claims] 1) A method for cleaning spent fuel assemblies in a nuclear reactor using liquid metal such as sodium as a primary coolant, comprising a cleaning tank for accommodating spent fuel assemblies, and the cleaning tank. a preheating step for raising the temperature of the spent fuel assembly to a predetermined temperature by the preheating means; The fuel assembly is cleaned by evaporating the liquid metal adhering to the fuel assembly through a depressurization step of reducing the pressure inside the cleaning tank using a decompression means while the spent fuel assembly is housed in the cleaning tank. A method for cleaning spent fuel assemblies. 2) In the cleaning method according to claim 1, the temperature of the spent fuel assembly is raised to a temperature higher than the melting temperature of the liquid metal in the preheating step, and the pressure in the cleaning tank is adjusted to the level of the liquid metal relative to the preheating temperature in the depressurization step. A method for cleaning a spent fuel assembly, characterized by reducing the pressure to below the saturated vapor pressure. 3) In the cleaning method according to claim 1, the preheating means is equipped with a blower, a gas heater, etc. and is connected to the cleaning tank, and heats the gas supplied from the inert gas source to heat the inside of the cleaning tank. A method for cleaning a spent fuel assembly, characterized in that the gas circulation line circulates between the 4) The cleaning method according to claim 1, characterized in that the depressurizing means is a depressurizing exhaust line equipped with a vacuum tank, a vacuum pump, etc., and connected between the cleaning tank and the gaseous waste treatment system. A method for cleaning spent fuel assemblies. 5) In the cleaning method according to claim 1, the liquid metal in the cleaning tank removed from the spent fuel assembly during cleaning of the spent fuel assembly is removed from the system. A method for cleaning a spent fuel assembly, characterized in that a liquid metal drain line for recovery is connected. 6) In the cleaning method according to claim 5, the liquid metal drain line extends from the bottom of the cleaning tank to the drain tank,
A method for cleaning a spent fuel assembly, characterized in that the spent fuel assembly is connected to a liquid metal recovery system via a liquid metal sending pump.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21303486A JPS6367598A (en) | 1986-09-10 | 1986-09-10 | Method of washing spent fuel aggregate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21303486A JPS6367598A (en) | 1986-09-10 | 1986-09-10 | Method of washing spent fuel aggregate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6367598A true JPS6367598A (en) | 1988-03-26 |
Family
ID=16632414
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21303486A Pending JPS6367598A (en) | 1986-09-10 | 1986-09-10 | Method of washing spent fuel aggregate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6367598A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102671878A (en) * | 2011-03-10 | 2012-09-19 | 中国原子能科学研究院 | Fast reactor spent component cleaning device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5193560A (en) * | 1975-02-15 | 1976-08-17 | Shinkujohatsunyoru natoriumukikisenjoho | |
| JPS5786800A (en) * | 1980-11-20 | 1982-05-29 | Tokyo Shibaura Electric Co | Cleaning device for decontaminated sodium instruments |
-
1986
- 1986-09-10 JP JP21303486A patent/JPS6367598A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5193560A (en) * | 1975-02-15 | 1976-08-17 | Shinkujohatsunyoru natoriumukikisenjoho | |
| JPS5786800A (en) * | 1980-11-20 | 1982-05-29 | Tokyo Shibaura Electric Co | Cleaning device for decontaminated sodium instruments |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102671878A (en) * | 2011-03-10 | 2012-09-19 | 中国原子能科学研究院 | Fast reactor spent component cleaning device |
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