JPH0640155B2 - Method for treating metallic sodium remaining on the equipment surface - Google Patents
Method for treating metallic sodium remaining on the equipment surfaceInfo
- Publication number
- JPH0640155B2 JPH0640155B2 JP60216739A JP21673985A JPH0640155B2 JP H0640155 B2 JPH0640155 B2 JP H0640155B2 JP 60216739 A JP60216739 A JP 60216739A JP 21673985 A JP21673985 A JP 21673985A JP H0640155 B2 JPH0640155 B2 JP H0640155B2
- Authority
- JP
- Japan
- Prior art keywords
- sodium
- metallic sodium
- clevis
- layer
- sodium hydroxide
- 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.)
- Expired - Lifetime
Links
- 239000011734 sodium Substances 0.000 title claims description 18
- 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 title claims description 17
- 229910052708 sodium Inorganic materials 0.000 title claims description 17
- 238000000034 method Methods 0.000 title claims description 16
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 26
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 16
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 13
- 239000001569 carbon dioxide Substances 0.000 claims description 8
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 8
- 239000007789 gas Substances 0.000 claims description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 5
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 5
- 230000000087 stabilizing effect Effects 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 230000006837 decompression Effects 0.000 claims 1
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 48
- 239000010410 layer Substances 0.000 description 15
- 238000011282 treatment Methods 0.000 description 14
- 238000005260 corrosion Methods 0.000 description 6
- 230000007797 corrosion Effects 0.000 description 6
- 239000003513 alkali Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- KEAYESYHFKHZAL-UHFFFAOYSA-N Sodium Chemical compound [Na] KEAYESYHFKHZAL-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000011221 initial treatment Methods 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000008439 repair process Effects 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910001338 liquidmetal Inorganic materials 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 150000003388 sodium compounds Chemical class 0.000 description 1
- 238000013020 steam cleaning Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000005292 vacuum distillation Methods 0.000 description 1
Landscapes
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は機器表面に付着残留した金属ナトリウムの安定
化を目的とした処理方法の改良に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an improvement in a treatment method for stabilizing metallic sodium remaining on the surface of equipment.
液体金属ナトリウム中で使用される機器、例えば原子力
プラントにおける蒸気発生器等の機器を点検したり補修
したりするためには、この機器を大気中に取出して１０
日〜１００日程度放置すると共に、機器表面に付着残存
している金属ナトリウムを洗浄、除去することが必要と
される。そのための手段としては、真空蒸留、アルコー
ル洗浄、蒸気洗浄、水洗浄等が従来一般に行なわれてい
た。In order to inspect and repair equipment used in liquid metal sodium, such as equipment such as steam generators in nuclear power plants, this equipment should be removed into the atmosphere and
It is necessary to stand for about 1 to 100 days and to wash and remove metallic sodium remaining on the surface of the device. As means for that purpose, vacuum distillation, alcohol cleaning, steam cleaning, water cleaning and the like have been generally performed conventionally.
しかし、機器表面のクレビス（微細な隙間）に充填され
た金属ナトリウムはこれらの方法をもってしても除去は
困難で、殆どの場合は幾らか残存するのを避けることが
できない。この状態で機器を大気中に曝しておくと、ク
レビス内では残存金属ナトリウムが徐々に大気中の水分
と反応して水酸化ナトリウム溶液を生成する。これは点
検や補修等の作業に支障をもたらすばかりでなく、機器
を再び金属ナトリウム中に浸漬して再使用するときは、
機器構成材にアルカリ応力腐食、腐食割れ等の悪影響を
及ぼす。However, it is difficult to remove the metallic sodium filled in the clevis (fine gap) on the surface of the device even by these methods, and in most cases, some remains cannot be avoided. When the device is exposed to the atmosphere in this state, the residual metallic sodium gradually reacts with the moisture in the atmosphere in the clevis to form a sodium hydroxide solution. This not only hinders work such as inspection and repair, but when re-immersing the device in metallic sodium again,
It adversely affects equipment components such as alkali stress corrosion and corrosion cracking.
そこで、上記のように機器表面に付着残留した金属ナト
リウムを安定化せしめ、アルカリ応力腐食やアルカリ腐
食割れ等を未然に防止する方法として、出願人は先に次
のような処理方法を提案した（特公昭６０−８７６０
号）。Therefore, as a method of stabilizing the metallic sodium remaining on the equipment surface as described above and preventing alkali stress corrosion, alkali corrosion cracking, etc., the applicant previously proposed the following treatment method ( Japanese Patent Publication 60-8760
issue).
この方法は、水含有流体で洗浄する一次処理工程と、炭
酸ガス雰囲気下に減圧加熱して付着しているナトリウム
化合物溶液を沸騰させる二次工程と、大気雰囲気に曝す
三次工程と、機器の再使用前に前記二次処理工程と同様
の操作を行なう四次処理工程とからなる四段階の処理方
法である。This method consists of a primary treatment step of washing with a water-containing fluid, a secondary step of heating under reduced pressure in a carbon dioxide gas atmosphere to boil the adhering sodium compound solution, a tertiary step of exposing to an atmospheric atmosphere, and a re-installation of equipment. It is a four-step treatment method comprising a quaternary treatment step in which the same operation as the secondary treatment step is performed before use.
第２図は上記特公昭６０−８７６０号の処理方法による
変化を示す説明図で、同図(A)は機器表面のクレビス内
に金属ナトリウム１が詰って残存している状態を示して
いる。これに前記一次処理工程を施すと、同図(B)に示
すように金属ナトリウム１の表層が水と反応して水酸化
ナトリウム層２を形成する。次いで前記二次処理工程を
施すと、水酸化ナトリウムと炭酸ガスとが反応し、同図
(C)に示すように水酸化ナトリウム層２の表層が炭酸ナ
トリウム層３に転化される。この状態で前記三次処理工
程を施すと、緻密な炭酸ナトリウム層３が大気中水分の
クレビス内部への拡散を防止すると共に、水酸化ナトリ
ウム層２との界面ではNaOHとNaCO3との混合が進行し、
遂には同図(D)に示すように両者の混合層４が形成され
る。その後に前記四次処理工程を施すと、混合層４はそ
の中のNaOHがNa2CO3に転化されてるため全体が炭酸ナト
リウム層３となり、クレビス内には水酸化ナトリウムが
ほぼ無くなることになる（同図(E)図示）。FIG. 2 is an explanatory view showing a change due to the treatment method of Japanese Patent Publication No. 60-8760, and FIG. 2 (A) shows a state in which the metallic sodium 1 remains in the clevis on the surface of the device. When this is subjected to the primary treatment step, the surface layer of metallic sodium 1 reacts with water to form sodium hydroxide layer 2, as shown in FIG. Next, when the secondary treatment step is applied, sodium hydroxide reacts with carbon dioxide gas,
As shown in (C), the surface layer of the sodium hydroxide layer 2 is converted into the sodium carbonate layer 3. When the third treatment step is performed in this state, the dense sodium carbonate layer 3 prevents diffusion of moisture in the atmosphere into the clevis, and at the interface with the sodium hydroxide layer 2, mixing of NaOH and NaCO 3 proceeds. Then
Finally, a mixed layer 4 of both is formed as shown in FIG. After that, when the fourth treatment step is applied, the mixed layer 4 has the sodium carbonate layer 3 as a whole because the NaOH therein is converted into Na 2 CO 3, and the sodium hydroxide is substantially eliminated in the clevis. (Figure (E) shown).
こうして、上記特公昭６０−８７６０号の処理方法によ
り、機器表面に水酸化ナトリウムが残留することによる
アルカリ腐食等の問題を未然に回避できることとなっ
た。Thus, by the treatment method of Japanese Patent Publication No. 60-8760, problems such as alkali corrosion due to the residual sodium hydroxide on the equipment surface can be avoided.
特公昭６０−８７６０号に開示された処理方法は極めて
有用なものであるが、処理工程が多いため長時間を要す
る問題があった。The treatment method disclosed in Japanese Examined Patent Publication No. Sho 60-8760 is extremely useful, but it has a problem that it takes a long time because of many treatment steps.
その主な原因は、クレビス内の金属ナトリウムを例えば
湿り窒素ガス等の水含有流体で洗浄する一次処理工程に
おいて、生成した水酸化ナトリウムがバリヤとなって反
応の進行が低下するためである。The main reason for this is that in the primary treatment step in which metallic sodium in clevis is washed with a water-containing fluid such as wet nitrogen gas, the generated sodium hydroxide acts as a barrier and the progress of the reaction is reduced.
上記事情に鑑み、本発明は特公昭６０−８７６０号に開
示された方法と同等以上の効果を有し、且つ短時間で処
理することができる方法を提供すべくなされたものであ
る。In view of the above circumstances, the present invention has been made to provide a method which has the same or more effects as the method disclosed in Japanese Patent Publication No. 60-8760 and which can be treated in a short time.
〔問題点を解決するための手段〕 本発明による処理方法は、金属ナトリウムの付着した機
器表面を加圧、大気圧、減圧等の圧力変動下に炭酸ガス
を混入した湿り窒素ガスで、一段階で洗浄することによ
り、付着している金属ナトリウムを炭酸ナトリウムに転
化し、安定化することを特徴とするものである。[Means for Solving Problems] The treatment method according to the present invention comprises a step of wet nitrogen gas mixed with carbon dioxide gas under pressure fluctuation such as pressurization, atmospheric pressure, depressurization, etc. on the equipment surface to which metal sodium is adhered It is characterized in that the adhered metallic sodium is converted into sodium carbonate and stabilized by washing with.
本発明において、金属ナトリウム付着機器の表面を湿り
窒素ガスおよび炭酸ガスの混合ガスで洗浄すると、水と
の反応で金属ナトリウム表面に生成した水酸化ナトリウ
ムが直ちに炭酸ガスと反応して膨潤した炭酸ナトリウム
となる。このため緻密な水酸化ナトリウム層によるバリ
ヤが形成されて反応速度が低下することはなく、順調に
反応が進行する。In the present invention, when the surface of a device for adhering sodium metal is washed with a mixed gas of wet nitrogen gas and carbon dioxide, sodium hydroxide produced on the surface of sodium metal by reaction with water immediately reacts with carbon dioxide and swells sodium carbonate. Becomes Therefore, a barrier is not formed by the dense sodium hydroxide layer and the reaction rate does not decrease, and the reaction proceeds smoothly.
また、加圧供給、大気圧、更には減圧といった圧力変動
を繰り返すことで上記の反応は一段と促進され、クレビ
スの内部にまで速やかに炭酸ガスが供給される。By repeating pressure fluctuations such as pressure supply, atmospheric pressure, and further pressure reduction, the above reaction is further promoted, and carbon dioxide gas is rapidly supplied to the inside of the clevis.
供試体として隙間0.5〜２mm、深さ５０mmのクレビス構
造体（鋼製）を十数個使用した。A dozen or more clevis structures (made of steel) having a gap of 0.5 to 2 mm and a depth of 50 mm were used as test pieces.
このクレビス構造体を液体金属ナトリウム中に浸漬し、
第１図(A)に示すようにクレビス内に金属ナトリウム１
を付着充填させた。次に、このクレビス構造体表面を炭
酸ガスを混入した湿り窒素ガスで処理したところ、第１
図(B)に示すように反応生成物として炭酸ナトリウム層
３が形成され、該炭酸ナトリウム層は膨れ上って多孔質
となった。更に、加圧および減圧を繰り返して処理した
ところ、反応は何等阻害されることなく進行し、第１図
(C)に示すように炭酸ナトリウム層３は一段と膨張して
クレビスの外にまで突出した。Immersing this clevis structure in liquid sodium metal,
As shown in Fig. 1 (A), metallic sodium 1 in the clevis
Was adhered and filled. Then, the surface of the clevis structure was treated with wet nitrogen gas mixed with carbon dioxide gas.
As shown in Figure (B), a sodium carbonate layer 3 was formed as a reaction product, and the sodium carbonate layer swollen and became porous. Further, when pressure and pressure were repeatedly treated, the reaction proceeded without any inhibition, and
As shown in (C), the sodium carbonate layer 3 further expanded and protruded to the outside of the clevis.
上記の処理の後、供試体を観察したところ、クレビス内
の残存物は全て炭酸ナトリウムになっていた。When the specimen was observed after the above treatment, all of the residue in the clevis was sodium carbonate.
以上詳述したように、本発明によれば機器表面に付着し
た水酸化ナトリウムを速やかに安定な炭酸ナトリウムに
転化し、水酸化ナトリウムが残留することによるアルカ
リ腐食等の問題を未然に防止できる等、顕著な効果が得
られるものである。As described above in detail, according to the present invention, sodium hydroxide attached to the equipment surface can be quickly converted into stable sodium carbonate, and problems such as alkali corrosion due to residual sodium hydroxide can be prevented. , A remarkable effect can be obtained.
第１図は本発明の一実施例になる処理過程を示す説明
図、第２図は従来の処理方法における過程を示す説明図
である。 １……金属ナトリウム、２……水酸化ナトリウム層、３
……炭酸ナトリウム層、４……水酸化ナトリウムおよび
炭酸ナトリウムの混在層。FIG. 1 is an explanatory view showing a processing process according to an embodiment of the present invention, and FIG. 2 is an explanatory view showing a process in a conventional processing method. 1 ... Sodium metal, 2 ... Sodium hydroxide layer, 3
... Sodium carbonate layer, 4 ... Mixed layer of sodium hydroxide and sodium carbonate.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 惣万 芳人 兵庫県神戸市兵庫区和田崎町１丁目１番１ 号 三菱重工業株式会社神戸造船所内 (56)参考文献 特開 昭50−148798（ＪＰ，Ａ) 特開 昭57−146199（ＪＰ，Ａ) 特開 昭56−165000（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshito Soma, 1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (56) Reference Japanese Patent Laid-Open No. 50-148798 ( JP, A) JP 57-146199 (JP, A) JP 56-165000 (JP, A)
Claims (1)
圧、大気圧、減圧等の圧力変動下に炭酸ガスを混入した
湿り窒素ガスで、一段階で洗浄することにより、付着し
ている金属ナトリウムを炭酸ナトリウムに転化し、安定
化することを特徴とする機器表面に付着残存した金属ナ
トリウムの処理方法。1. A metal adhering to a device surface to which metallic sodium is adhered, which is washed in one step with moist nitrogen gas mixed with carbon dioxide gas under pressure fluctuations such as pressurization, atmospheric pressure and decompression. A method for treating metallic sodium remaining on the surface of a device, which comprises stabilizing sodium by converting it into sodium carbonate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60216739A JPH0640155B2 (en) | 1985-09-30 | 1985-09-30 | Method for treating metallic sodium remaining on the equipment surface |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60216739A JPH0640155B2 (en) | 1985-09-30 | 1985-09-30 | Method for treating metallic sodium remaining on the equipment surface |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6275396A JPS6275396A (en) | 1987-04-07 |
| JPH0640155B2 true JPH0640155B2 (en) | 1994-05-25 |
Family
ID=16693171
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60216739A Expired - Lifetime JPH0640155B2 (en) | 1985-09-30 | 1985-09-30 | Method for treating metallic sodium remaining on the equipment surface |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0640155B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0667649U (en) * | 1993-02-26 | 1994-09-22 | 株式会社サカタ製作所 | Tight frame structure |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7399803B2 (en) * | 2020-07-01 | 2023-12-18 | 株式会社東芝 | Alkali metal stabilization method and stabilization device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5316074B2 (en) * | 1974-05-23 | 1978-05-29 | ||
| JPS57146199A (en) * | 1981-03-05 | 1982-09-09 | Tokyo Shibaura Electric Co | Evaporating and cleaning device |
-
1985
- 1985-09-30 JP JP60216739A patent/JPH0640155B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0667649U (en) * | 1993-02-26 | 1994-09-22 | 株式会社サカタ製作所 | Tight frame structure |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6275396A (en) | 1987-04-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |