JPH0631815B2 - Nuclear power plant water supply system - Google Patents
Nuclear power plant water supply systemInfo
- Publication number
- JPH0631815B2 JPH0631815B2 JP60087212A JP8721285A JPH0631815B2 JP H0631815 B2 JPH0631815 B2 JP H0631815B2 JP 60087212 A JP60087212 A JP 60087212A JP 8721285 A JP8721285 A JP 8721285A JP H0631815 B2 JPH0631815 B2 JP H0631815B2
- Authority
- JP
- Japan
- Prior art keywords
- condensate
- concentration
- iron
- water supply
- water
- 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
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims description 81
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 93
- 229910052742 iron Inorganic materials 0.000 claims description 51
- -1 iron ion Chemical class 0.000 claims description 23
- 238000000746 purification Methods 0.000 claims description 20
- 230000007797 corrosion Effects 0.000 claims description 16
- 238000005260 corrosion Methods 0.000 claims description 16
- 229910000975 Carbon steel Inorganic materials 0.000 claims description 13
- 239000010962 carbon steel Substances 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 10
- 238000005468 ion implantation Methods 0.000 claims 1
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 21
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 14
- 229910052760 oxygen Inorganic materials 0.000 description 14
- 239000001301 oxygen Substances 0.000 description 14
- 239000000446 fuel Substances 0.000 description 12
- 238000002347 injection Methods 0.000 description 11
- 239000007924 injection Substances 0.000 description 11
- 150000002500 ions Chemical class 0.000 description 11
- 238000005070 sampling Methods 0.000 description 10
- 229910052759 nickel Inorganic materials 0.000 description 9
- 239000002184 metal Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 150000001875 compounds Chemical class 0.000 description 5
- 238000010828 elution Methods 0.000 description 4
- 206010003445 Ascites Diseases 0.000 description 3
- 238000009835 boiling Methods 0.000 description 3
- 239000002826 coolant Substances 0.000 description 3
- 239000000498 cooling water Substances 0.000 description 3
- 238000011033 desalting Methods 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000012857 radioactive material Substances 0.000 description 3
- 239000000941 radioactive substance Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005868 electrolysis reaction Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910001453 nickel ion Inorganic materials 0.000 description 2
- 238000011045 prefiltration Methods 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- VEQPNABPJHWNSG-UHFFFAOYSA-N Nickel(2+) Chemical compound [Ni+2] VEQPNABPJHWNSG-UHFFFAOYSA-N 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000010612 desalination reaction Methods 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 239000012510 hollow fiber Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- UGKDIUIOSMUOAW-UHFFFAOYSA-N iron nickel Chemical compound [Fe].[Ni] UGKDIUIOSMUOAW-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- SPIFDSWFDKNERT-UHFFFAOYSA-N nickel;hydrate Chemical compound O.[Ni] SPIFDSWFDKNERT-UHFFFAOYSA-N 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Control Of Steam Boilers And Waste-Gas Boilers (AREA)
- Monitoring And Testing Of Nuclear Reactors (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Description
【発明の詳細な説明】 〔発明の利用分野〕 本発明は原子力発電プラントにおいて一次系配管の表面
線量率を低減するようにした原子力発電プラントの給水
系統に関する。Description: FIELD OF THE INVENTION The present invention relates to a water supply system of a nuclear power plant for reducing the surface dose rate of primary system piping in the nuclear power plant.
沸騰水型原子力発電プラントの炉水中の放射能濃度及び
配管表面線量の上昇は、プラント構成機器、配管等より
発生した腐食生成物が給水系等から原子炉に持込まれ、
燃料棒表面で中性子照射により放射化された後、再び一
次系機器、配管に付着することによるとされる。腐食生
成物としては、Ｆｅ，Ｃｏ，Ｎｉなどあり、中性子照射
により、ＣｏがＣｏ−６０，ＮｉがＣｏ−５８核種にな
る。この際Ｆｅは不溶解性生成物（クラッド）として存
在し、燃料棒表面上で付着はく離を繰り返すが、Ｎｉや
Ｃｏは、そのＦｅクラッドに吸着脱着しながら放射化さ
れる。したがって、給水系から持込まれるＦｅクラッド
は、約１ｐｐｂ以下の濃度に抑制する方が、ＣｏやＮｉ
の放射化、および原子炉一次系配管への付着を抑制で
き、しいてはプラントの放射能レベルを低減できること
が高島らにより日立評論ＶＯＬ、６２No.９（１９８０
年）で知られている。The increase in the radioactivity concentration in the reactor water of boiling water nuclear power plants and the increase in the surface dose of piping are caused by the corrosion products generated from plant components, piping, etc. being brought into the reactor from the water supply system, etc.
It is said that the surface of the fuel rod is activated by neutron irradiation and then attached again to the primary system equipment and piping. Corrosion products include Fe, Co, and Ni, and upon neutron irradiation, Co becomes Co-60 and Ni becomes Co-58 nuclide. At this time, Fe exists as an insoluble product (clad) and is repeatedly adhered and separated on the surface of the fuel rod, but Ni and Co are activated by adsorption and desorption on the Fe cladding. Therefore, it is better to suppress the Fe clad brought in from the water supply system to a concentration of about 1 ppb or less.
Takata et al., Vol. 62 No. 9 (1980) by Takashima et al. That it can suppress the activation of water and the adhesion to the primary piping of the reactor, and thus reduce the level of radioactivity of the plant.
Years).
したがって、最近の沸騰水型原子力発電プラントでは、
クラッドの低減対策として、復水系のクラッドを除去す
るため、復水浄化系を復水脱塩器と復水前置フィルター
の二重化によりクラッドの除去効率アップを図り、ま
た、抽気系や復水器に耐食性の良い材料を採用して、ク
ラッドの発生量を低減し、さらに給水系への酸素注入に
より、給水配管・機器の材料表面に安定な酸化皮膜を形
成させ、防食を図ることが一般化している。これにより
給水系の鉄クラッド濃度を容易に１ｐｐｂ以下にするこ
とが可能なシステムになっている。Therefore, in recent boiling water nuclear power plants,
As a measure to reduce the clad in the condensate system, the condensate purification system is doubled in the condensate demineralizer and the condensate pre-filter to improve the clad removal efficiency. It is common practice to use a material with good corrosion resistance to reduce the amount of clad generation, and to inject oxygen into the water supply system to form a stable oxide film on the material surface of water supply pipes and equipment to prevent corrosion. ing. This makes it possible to easily reduce the iron clad concentration in the water supply system to 1 ppb or less.
ここで前述したようなクラッド低減対策を適用した沸騰
水型原子力発電プラントのシステム構成を第８図で以下
説明する。Here, the system configuration of the boiling water nuclear power plant to which the above-described clad reduction measure is applied will be described below with reference to FIG.
原子炉１で発生した蒸気はタービン復水器１０で復水と
して回収された後、復水フィルター１２と復水脱塩器１
３で水処理され、給水加熱器１４で加熱された後、原子
炉１に回収される。原子炉１の保有水は、原子炉浄化系
４の過脱塩器６で浄化される。The steam generated in the reactor 1 is recovered as condensate by the turbine condenser 10, and then the condensate filter 12 and the condensate demineralizer 1 are collected.
Water is treated in 3 and heated in the feed water heater 14 and then recovered in the reactor 1. The water held in the nuclear reactor 1 is purified by the over-desalination unit 6 of the nuclear reactor purification system 4.
給水系には酸素ボンベ２２と酸素注入ライン２１から構
成される酸素注入系により２０〜２００ｐｐｂの酸素が
注入され、給水系配管機器の表面に酸化皮膜を形成さ
せ、防食を図り、給水系では鉄クラッドの発生が抑制さ
れる。また、給復水系のＦｅクラッドやＮｉイオン等の
濃度は、サンプリングライン１５，１６，１７，１８よ
り、一次冷却水をサンプリングし、濃度を分析測定し監
視できる。20 to 200 ppb of oxygen is injected into the water supply system by the oxygen injection system composed of the oxygen cylinder 22 and the oxygen injection line 21, and an oxide film is formed on the surface of the water supply system piping equipment to prevent corrosion, and the iron is used in the water supply system. Generation of clad is suppressed. Further, the concentrations of the Fe clad and Ni ions in the water supply / condensation system can be monitored by sampling the primary cooling water from the sampling lines 15, 16, 17, 18 and analyzing and measuring the concentration.
第９図には復水フィルター１２を前置フィルタとした復
水浄化系の従来のシステム構成例を示す。FIG. 9 shows a conventional system configuration example of a condensate purification system using the condensate filter 12 as a prefilter.
タービン復水器にて回収された復水は、接液材料の腐食
により発生した鉄クラッドを除去するため、並列に１２
基（その内１期は待機）設けられた復水フィルター１２
により浄化させる。腹水フィルター１２は、各塔流量を
均一に制御するために、流量計３０により流量を検知
し、各塔の流量制御弁３２により、流量が調節制御され
る。また、差圧の異常上昇やプラント停止時の給復水再
循環運転時のバイパス運転に対処するため、バイパスラ
イン４２が設けられ、バイパス弁４１の開閉によりプラ
ント運転時、定格流量の約３分の１を通水することがで
きる。Condensed water collected by the turbine condenser is parallel to 12 times in order to remove the iron clad generated by the corrosion of the wetted material.
Condensate filter 12 equipped with a base (one of which is on standby)
Purify by. The ascites filter 12 detects the flow rate by the flow meter 30 and controls the flow rate by the flow rate control valve 32 of each tower in order to uniformly control the flow rate of each tower. Further, a bypass line 42 is provided in order to cope with an abnormal increase in the differential pressure and a bypass operation at the time of supply / condensate recirculation operation when the plant is stopped, and by opening / closing the bypass valve 41, at the time of plant operation, about 3 minutes of the rated flow rate. 1 can be passed through.
一方、腹水フィルター１２の下流には復水脱塩器１３が
設けられ、これは特に復水器チューブ破損時の海水リー
クの処理、すなわち原子炉内への塩素イオン流量防止を
目的とする。On the other hand, a condensate demineralizer 13 is provided downstream of the ascites filter 12 for the purpose of treating seawater leaks especially when the condenser tube is broken, that is, for preventing chlorine ion flow rate into the reactor.
本発明の目的は、プラントの定常運転時に、燃料棒表面
からの放射性物質の溶出又は剥離を抑制し、原子力発電
プラントの放射能レベルを低下させるのに好適な給水系
統を提供することにある。An object of the present invention is to provide a water supply system that is suitable for suppressing elution or separation of radioactive substances from the surface of fuel rods during steady operation of the plant and reducing the radioactivity level of the nuclear power plant.
上記目的を達成するために、本発明は、タービン復水器
で回収した復水を浄化する復水浄化装置を備えた原子力
発電プラントの給水系統において、前記復水浄化装置の
下流側に鉄イオン注入装置を設け、前記プラントの定常
運転時に、給水中の鉄濃度を０．１〜１．２ｐｐｂの範
囲に制御するようにしたものである。In order to achieve the above object, the present invention is a water supply system of a nuclear power plant equipped with a condensate purification device that purifies the condensate collected by a turbine condenser, and iron ions are provided downstream of the condensate purification device. An injection device is provided to control the iron concentration in the feed water within the range of 0.1 to 1.2 ppb during the steady operation of the plant.
鉄イオン注入装置としては、腐食により鉄を発生して復
水中に注入する装置や、復水系から一部バイパスさせた
溶存酸素濃度の低い復水中又は脱気水中に炭素鋼材から
なる金属片を浸漬して腐食させ、これにより発生した鉄
を再度復水中に注入する装置などを用いることができ
る。As an iron ion injection device, a device that generates iron by corrosion and injects it into condensate, or a metal piece made of carbon steel is immersed in condensate or degassed water with a low dissolved oxygen concentration partially bypassed from the condensate system. It is possible to use, for example, a device for injecting the resulting iron into the condensate again.
また、鉄粉を注入する装置、鉄粉を自然腐食させて注入
する装置、電気分解により強制的に鉄イオンを発生させ
て鉄イオンを注入する装置なども用いることができる。Further, a device for injecting iron powder, a device for injecting iron powder by spontaneous corrosion, a device for forcibly generating iron ions by electrolysis and injecting iron ions, and the like can also be used.
しかし、最も簡単に実現する方法として、溶存酸素濃度
の低い復水中に炭素鋼材を浸漬させ、自然腐食で発生す
る鉄を復水中に注入することにより、安価で且つＮｉイ
オンと結合性の良い鉄イオンを注入することができる。However, the easiest way to achieve this is to immerse the carbon steel material in condensate with a low dissolved oxygen concentration, and inject the iron generated by natural corrosion into the condensate to make the iron inexpensive and having good binding properties with Ni ions. Ions can be implanted.
上記構成を備えた本発明によれば、Ｆｅクラッド濃度
を、給水中の金属不純物（特にＮｉイオン）濃度に応じ
て十分に結合安定可能な濃度に制御できるので、炉水中
の放射能濃度の増加を抑制し、ひいては原子力発電プラ
ントの放射能レベルを低下させることができる。According to the present invention having the above-described configuration, the Fe clad concentration can be controlled to a concentration capable of sufficiently binding and stabilizing according to the concentration of metal impurities (particularly Ni ions) in the feed water, so that the radioactivity concentration in the reactor water can be increased. Can be suppressed, and the radioactivity level of the nuclear power plant can be lowered.
即ち、上記構成を備えることにより、炉水中のＮｉ，Ｃ
ｏは燃料棒表面に付着しているＦｅクラッドと反応して
鉄ニッケル複合化合物ＮｉＯＦｅ2Ｏ3などを形成する。
この化合物は燃料棒表面に安定に付着するので、化合物
中のＮｉ，Ｃｏが中性子照射で放射化されても、燃料棒
表面から炉水中への放射性物質の溶出を抑制することが
できる。従って、一次冷却水が接する一次系配管・機器
への放射性物質の付着量を低減し、原子力発電プラント
の放射能レベルを低下させることができる。That is, by having the above configuration, Ni, C in the reactor water
o reacts with the Fe clad adhering to the surface of the fuel rod to form an iron-nickel composite compound NiOFe 2 O 3 or the like.
Since this compound is stably attached to the surface of the fuel rod, elution of radioactive substances from the surface of the fuel rod into the reactor water can be suppressed even if Ni and Co in the compound are activated by neutron irradiation. Therefore, it is possible to reduce the amount of radioactive material attached to the primary system pipes / equipment with which the primary cooling water comes into contact, and to reduce the radioactivity level of the nuclear power plant.
尚、復水浄化装置としては、復水フィルターと復水脱塩
器を組合せた装置や、復水フィルターのみの装置を用い
ることができる。As the condensate purification device, a device combining a condensate filter and a condensate demineralizer or a device having only a condensate filter can be used.
次に、上述した効果について第７図の測定例を用いてよ
り詳細に説明する。第７図はプラントの運転時間に対す
る給水鉄（クラッド）濃度と炉水中放射能濃度の変化
を、典型的な２種類のプラント（プラントＡとプラント
Ｂ）について測定した結果である。同図から、初期運転
時、定常運転時共に、給水中の鉄濃度が適度に高い方が
炉水中の放射能濃度を低く抑えられ、鉄濃度が極端に低
いとむしろ炉水中の放射能濃度は高くなることがわか
る。Next, the effect described above will be described in more detail with reference to the measurement example of FIG. FIG. 7 shows the results of measuring changes in the feed water iron (clad) concentration and the reactor water radioactivity concentration with respect to the operating time of the plant for two typical types of plants (plant A and plant B). From the figure, both during initial operation and during steady operation, an appropriately high iron concentration in the feedwater can suppress the radioactivity concentration in the reactor water to a low level, and if the iron concentration is extremely low, the radioactivity concentration in the reactor water is rather high. You can see that it will be higher.
これは、給水中の鉄濃度が極端に低いと、燃料棒表面に
Ｎｉ，Ｃｏが安定に付着できないので、Ｎｉ，Ｃｏが中
性子照射により放射化され炉水中に溶出し、炉水中の放
射性核種Ｃｏ−５８などの濃度が増加することによるも
のと考えられる。This is because when the iron concentration in the feed water is extremely low, Ni and Co cannot be stably attached to the surface of the fuel rod, so Ni and Co are activated by neutron irradiation and are eluted into the reactor water, and the radioactive nuclide Co in the reactor water is dissolved. It is considered that this is because the concentration of −58 and the like increased.
また、給水中の鉄濃度が極端に高いと、燃料棒表面に付
着したＦｅクラッドが剥離し易くなるので、これと共に
ＦｅクラッドとＮｉ，Ｃｏが反応して生成した前記化合
物も剥離し易くなる。このため、化合物中のＮｉ，Ｃｏ
が中性子照射により放射化されて炉水中に剥離し、炉水
中の放射能濃度を増加させることになる。Further, when the iron concentration in the feed water is extremely high, the Fe clad adhering to the surface of the fuel rod is likely to be peeled off, so that the compound produced by the reaction between the Fe clad and Ni, Co is also easily peeled off. Therefore, Ni, Co in the compound
Will be activated by neutron irradiation and will be separated into the reactor water, increasing the radioactivity concentration in the reactor water.
第６図に典型的な給水中のＦｅ，Ｎｉ金属濃度の経時変
化を示す。同図に示すように給水の水質制御を実施しな
い場合、給水加熱器チューブ等で主として発生するＮｉ
イオン濃度がＦｅ濃度に比べて高くなり、前述したよう
なメカニズムで炉水中の放射能濃度が増加することにな
る。従って、給水中のＦｅ濃度を制御して、第６図の曲
線IIIの例のようにＮｉイオンと結合するのに十分なＦ
ｅ濃度を確保する必要がある。FIG. 6 shows typical changes over time in the Fe and Ni metal concentrations in the feed water. As shown in the figure, when the water quality control of the feed water is not performed, Ni mainly generated in the feed water heater tube or the like is used.
The ion concentration becomes higher than the Fe concentration, and the radioactivity concentration in the reactor water increases due to the mechanism as described above. Therefore, it is necessary to control the Fe concentration in the feed water so that the F concentration is sufficient to combine with Ni ions as in the example of curve III in FIG.
It is necessary to secure the e concentration.
実際には、第６図の曲線Ｉで示すように給水中のＮｉイ
オン濃度は初期運転時に激しく変化し、濃度そのものも
プラントによって様々な値をとるので、これに応じてＦ
ｅ濃度を制御することはかなり難しい。一方、定常運転
時のＮｉイオン濃度は第６図の曲線Ｉからも分かるよう
にほぼ安定しており、プラント間の差も比較的小さいの
で、これに応じてＦｅ濃度を制御することは初期運転時
に比べて容易となる。従って、前述したように、本発明
では定常運転時の給水中Ｆｅ濃度を、第５図の炭素鋼接
液面積にして５０〜２００m2に当る、０．１〜１．２ｐ
ｐｂの範囲に制御することにより、燃料棒表面からの放
射性物質の溶出又は剥離を抑制しようとするものであ
る。Actually, as shown by the curve I in FIG. 6, the Ni ion concentration in the feed water changes drastically during the initial operation, and the concentration itself takes various values depending on the plant.
It is quite difficult to control the e concentration. On the other hand, the Ni ion concentration during steady operation is almost stable, as can be seen from the curve I in FIG. 6, and the difference between plants is relatively small. Sometimes it's easier. Therefore, as described above, in the present invention, the Fe concentration in the feed water during steady operation corresponds to 50 to 200 m 2 in terms of the wetted area of carbon steel in FIG.
By controlling in the range of pb, it is intended to suppress elution or separation of radioactive material from the surface of the fuel rod.
本発明の実施例を第１図により以下説明する。復水フィ
ルター１２と復水脱塩器１３から構成される復水浄化系
において、復水は復水母管３８より復水フィルター１２
に流入し処理される。本発明では復水脱塩器の下流側
に、鉄イオン発生装置６０と鉄イオン注入配管弁から成
る鉄イオン注入系を設けることを特徴とする。本実施例
によれば、注入鉄イオンの濃度、または、注入流量の制
御により給水の鉄濃度を制御できる。また、第２案の実
施例を第２図に示す。本実施例では給水系配管・機器内
面に安定した酸化保護皮膜を形成させ、腐食を抑制する
ために、給水系溶存酸素濃度を２０〜２００ｐｐｂに制
御できるよう、酸素注入系２１を有する。本発明によれ
ば、この酸素注入点よりも上流側より一部バイパスした
復水を用いて、鉄イオン発生装置６０を介して、復水脱
塩器出口に復水を戻し、給水中の金属濃度を制御するこ
とを特徴とした復水浄化システムを示す。An embodiment of the present invention will be described below with reference to FIG. In the condensate purification system including the condensate filter 12 and the condensate demineralizer 13, the condensate is collected from the condensate mother pipe 38.
And is processed. The present invention is characterized in that an iron ion injection system including an iron ion generator 60 and an iron ion injection pipe valve is provided on the downstream side of the condensate demineralizer. According to the present embodiment, the iron concentration of the feed water can be controlled by controlling the concentration of the injected iron ions or the injection flow rate. An embodiment of the second plan is shown in FIG. In this embodiment, an oxygen injection system 21 is provided so that the dissolved oxygen concentration in the water supply system can be controlled to 20 to 200 ppb in order to form a stable oxidation protection film on the inner surface of the water supply system pipe / device and suppress corrosion. According to the present invention, the condensate partially bypassed from the upstream side of the oxygen injection point is used to return the condensate to the outlet of the condensate demineralizer via the iron ion generator 60, and the metal in the feed water is supplied. 1 shows a condensate purification system characterized by controlling concentration.
また、第３図に上記実施例における鉄イオン発生装置の
構造図例を示す。本図に示すように鉄イオン発生装置は
液体の出入りが可能な装置内に約５０〜２００m2の表面
積を有する炭素鋼材料を内部に設けたことを特徴とす
る。また、本発明の実施例によれば、第４図に示すよう
に炭素鋼の腐食速度は、浸漬液体中の溶存酸素濃度によ
り大きく変化し、特に２０ｐｐｂ以上になれば、腐食量
が低減し、鉄イオンの発生速度が抑制される。このよう
な腐食特性により、溶存酸素濃度が低い条件下では、鉄
イオン発生装置内の炭素鋼材料の接液面積が少さくて
も、給水系の鉄濃度を制御できる。第５図は、その炭素
鋼材の接液面積と給水鉄濃度の関係を示したものであ
る。本図に示すように例えば、給水系の鉄濃度の増加量
を最大０．３ｐｐｂとする場合、炭素鋼の材料表面積を
約５０〜１００m2とすることにより、対処できる。ま
た、鉄濃度の制御は、復水のバイパス系統の流量制御あ
るいは、脱気による溶存酸素濃度制御により行なうこと
ができる。Further, FIG. 3 shows an example of a structural diagram of the iron ion generator in the above embodiment. As shown in the figure, the iron ion generator is characterized in that a carbon steel material having a surface area of about 50 to 200 m 2 is provided inside a device that allows liquid to flow in and out. Further, according to the example of the present invention, as shown in FIG. 4, the corrosion rate of carbon steel greatly changes depending on the concentration of dissolved oxygen in the immersion liquid, and particularly when it is 20 ppb or more, the corrosion amount decreases, The generation rate of iron ions is suppressed. Due to such corrosion characteristics, under conditions where the dissolved oxygen concentration is low, the iron concentration in the water supply system can be controlled even if the contact area of the carbon steel material in the iron ion generator is small. FIG. 5 shows the relationship between the wetted area of the carbon steel material and the iron concentration in the feed water. As shown in the figure, for example, when the increase amount of iron concentration in the water supply system is set to 0.3 ppb at the maximum, it can be dealt with by setting the material surface area of carbon steel to about 50 to 100 m 2 . The iron concentration can be controlled by controlling the flow rate of the condensate bypass system or controlling the dissolved oxygen concentration by degassing.
次に本発明の実施例による給水水質の制御の例を第６図
に示す。第６図中の曲線IIは制御を特に行わない場合の
給水鉄クラッド濃度の経時変化を示す。一方、曲線III
は腹水浄化系による給水水質制御を行なった場合の給水
鉄クラッド濃度を経時変化を示すが、本発明によれば給
水ニッケルイオン濃度の推移に伴わせて、容易にクラッ
ド濃度を制御できる。Next, FIG. 6 shows an example of the control of the water quality of the water supply according to the embodiment of the present invention. Curve II in FIG. 6 shows the change over time in the iron clad concentration in the feed water when no control is performed. On the other hand, curve III
Shows the change over time in the feed iron clad concentration when the feed water quality is controlled by the ascites purification system. According to the present invention, the clad concentration can be easily controlled in accordance with the transition of the feed water nickel ion concentration.
このような給水系水質制御により、Ｎｉイオンと結合
し、燃料棒表面に安定付着するのに十分なＦｅクラッド
を制御可能である。これにより炉水放射能の上昇を制御
し、さらに第７図に示すプラントＡの例のように、プラ
ントの一次系配管表面線量率の上昇抑制を図ることがで
きる。By controlling the water quality of the water supply system as described above, it is possible to control the Fe clad sufficient to bond with Ni ions and stably adhere to the surface of the fuel rod. This makes it possible to control an increase in reactor water radioactivity and further suppress an increase in the surface dose rate of the primary piping of the plant as in the example of the plant A shown in FIG. 7.
また、特に、本実施例によれば、給水系の鉄の形態はイ
オン状態であるため、給水系で発生するニッケルイオン
とも、化学反応により容易に結合安定できるため、燃料
棒表面においても容易に付着し安定しうるものである。Further, in particular, according to the present embodiment, since the form of iron in the water supply system is in an ionic state, it is possible to easily bond and stabilize nickel ions generated in the water supply system by a chemical reaction. It can adhere and be stable.
Ｎｉ２＋＋２Ｆｅ３＋＋２０２→ＮｉＦｅ２Ｏ４ なお、以上の復水浄化系のバイパスによる鉄濃度制御は
復水脱塩器下流側に鉄イオンを注入するものであった
が、復水フィルターと復水脱塩器の間に注入するもので
あっても実施可能である。また、さらに復水フィルター
単独の復水浄化系においても同様に適用できるものであ
る。Ni 2+ + 2Fe 3+ +20 2 → NiFe 2 O 4 The iron concentration control by bypass of the condensate purification system described above was to inject iron ions into the downstream side of the condensate demineralizer. It can be carried out even if it is injected between water desalting devices. Further, it can be similarly applied to a condensate purification system having a condensate filter alone.
本発明は、復水浄化系精密過膜装置（中空糸膜フィル
ター）、粉末式過脱塩器や電磁フィルター等、の復水
フィルターについて容易に適用可能なものである。INDUSTRIAL APPLICABILITY The present invention can be easily applied to a condensate filter such as a condensate purifying system precision permeation apparatus (hollow fiber membrane filter), a powder type super desalting device, and an electromagnetic filter.
また、鉄イオン注入装置は、容器内に炭素鋼板を並べる
案の他に、鉄粉、鉄球または繊維状の鉄材を装荷したも
のでも可能である。また、電気分解により強制的に電解
鉄イオンを発生できる鉄イオン発生装置も適用可能であ
る。Further, the iron ion implanting device may be a device in which iron powder, iron balls or fibrous iron material is loaded, in addition to the plan of arranging carbon steel plates in the container. Further, an iron ion generator that can forcibly generate electrolytic iron ions by electrolysis is also applicable.
本発明によれば、プラントの定常運転時に、給水中のＦ
ｅ濃度を、給水中の金属不純物（特にＮｉイオン）濃度
に応じて十分に結合安定可能な濃度に制御できるので、
炉水中のＮｉイオンを燃料棒表面に安定付着させ、燃料
棒表面から炉水中への放射性物質の溶出又は剥離を抑制
することができる。従って、一次冷却水が接する一次系
配管・機器への放射性物質の付着量を低減し、原子力発
電プラントの放射能レベルを低下させることができる。
これにより、更に作業員の被爆を低減することもでき
る。According to the present invention, during steady operation of the plant, the F
Since the e concentration can be controlled to a concentration capable of sufficiently binding and stabilizing according to the concentration of metal impurities (particularly Ni ions) in the feed water,
Ni ions in the reactor water can be stably attached to the surface of the fuel rod, and elution or separation of radioactive substances from the surface of the fuel rod into the reactor water can be suppressed. Therefore, it is possible to reduce the amount of radioactive material attached to the primary system pipes / equipment with which the primary cooling water comes into contact, and to reduce the radioactivity level of the nuclear power plant.
Thereby, the exposure of the worker can be further reduced.
第１図は本発明の実施例、第２図は本発明の実施例、第
３図は鉄イオン発生装置の構造図、第４図は炭素鋼の腐
食速度、第５図は給水鉄濃度と炭素鋼接液面積、第６図
は給水系金属濃度制御の実施例、第７図は給水鉄濃度と
炉水放射能、第８図は試料採取点、第９図は従来の実施
例を示す。 １……原子炉圧力容器、２……原子炉再循環系、３……
原子炉再循環ポンプ、４……原子炉冷却材浄化系、５…
…原子炉冷却材浄化系熱交換器、６……原子炉冷却材浄
化系過脱塩器、７……主蒸気系、８……給水系、９…
…給復水再循環系、１０……タービン復水器、１１……
低圧復水ポンプ、１２……復水フィルター、１３……復
水脱塩器、１４……給水加熱器、１５……復水ポンプ出
口水試料採取系、１６……復水フィルター出口水試料採
取系、１７……復水脱塩器出口水試料採取系、１８……
給水系試料採取点、１９……金属不純物採取用ミリポア
サンプリングホルダー、２０……試料採取系ラック、２
１……酸素注入系、３０……復水フィルター各塔流量
計、３１……復水フィルター各塔入口弁、３２……復水
フィルター各塔流量制御弁、３３……給水系、３４……
復水脱塩器入口弁、３５……復水脱塩器出口弁、３６…
…復水脱塩器各塔流量計、３７……復水系流量計、３８
……復水系、４１……復水フィルターバイパス弁、４２
……復水フィルターバイパス系、４３……復水脱塩器バ
イパス弁、４４……復水脱塩器バイパス系、５６……復
水浄化系バイパス系流量計、５７……復水浄化系バイパ
ス系流量制御弁、５８……復水浄化系バイパス系、５９
……復水浄化系バイパス系流量制御装置、６０……鉄イ
オン発生装置、６１……鉄イオン注入系統、６２……鉄
イオン発生用炭素鋼板。FIG. 1 is an embodiment of the present invention, FIG. 2 is an embodiment of the present invention, FIG. 3 is a structural diagram of an iron ion generator, FIG. 4 is a corrosion rate of carbon steel, and FIG. Carbon steel wetted area, Fig. 6 shows an example of feed water metal concentration control, Fig. 7 shows feed water iron concentration and reactor water radioactivity, Fig. 8 shows sampling points, and Fig. 9 shows a conventional example. . 1 ... Reactor pressure vessel, 2 ... Reactor recirculation system, 3 ...
Reactor recirculation pump, 4 ... Reactor coolant purification system, 5 ...
… Reactor coolant purification system heat exchanger, 6 …… Reactor coolant purification system super desalting system, 7 …… Main steam system, 8 …… Water supply system, 9 ...
… Supply / condensate recirculation system, 10 …… Turbine condenser, 11 ……
Low-pressure condensate pump, 12 ... Condensate filter, 13 ... Condensate demineralizer, 14 ... Feed water heater, 15 ... Condensate pump outlet water sampling system, 16 ... Condensate filter outlet water sampling System, 17 …… Condensate demineralizer outlet water sampling system, 18 ……
Water sampling system sampling points, 19 ... Millipore sampling holder for collecting metallic impurities, 20 ... Sampling system rack, 2
1 ... Oxygen injection system, 30 ... Condenser filter tower flow meter, 31 ... Condenser filter tower inlet valve, 32 ... Condenser filter tower flow control valve, 33 ... Water supply system, 34 ...
Condensate demineralizer inlet valve, 35 ... Condensate demineralizer outlet valve, 36 ...
… Condensate demineralizer tower flowmeters, 37 …… Condensate flowmeters, 38
…… Condensate system, 41 …… Condensate filter bypass valve, 42
…… Condensate filter bypass system, 43 …… Condensate demineralizer bypass valve, 44 …… Condensate demineralizer bypass system, 56 …… Condensate purification system bypass flow meter, 57 …… Condensate purification system bypass System flow control valve, 58 ... Condensate purification system bypass system, 59
...... Condensate purification system bypass system flow controller, 60 …… Iron ion generator, 61 …… Iron ion injection system, 62 …… Carbon steel for iron ion generation.
フロントページの続き (72)発明者 伊藤 久雄 茨城県日立市幸町３丁目１番１号 株式会 社日立製作所日立工場内 (56)参考文献 特開 昭55−63798（ＪＰ，Ａ)Front page continuation (72) Inventor Hisao Ito 3-1-1 Sachimachi, Hitachi, Ibaraki Hitachi Ltd. Hitachi factory (56) References JP-A-55-63798 (JP, A)
Claims (3)
復水浄化装置を備えた原子力発電プラントの給水系統に
おいて、 前記復水浄化装置の下流側に鉄イオン注入装置を設け、
前記プラントの定常運転時に、給水中の鉄濃度を０．１
〜１．２ｐｐｂの範囲に制御することを特徴とする原子
力発電プラントの給水系統。1. In a water supply system of a nuclear power plant equipped with a condensate purification device for purifying condensate collected by a turbine condenser, an iron ion implantation device is provided downstream of the condensate purification device,
During steady operation of the plant, the iron concentration in the feed water was adjusted to 0.1
A water supply system for a nuclear power plant, which is controlled to a range of 1.2 ppb.
ら取り出した復水を炭素鋼材料に接触させて腐食させ、
該腐食により発生した鉄イオンを注入することを特徴と
する原子力発電プラントの給水系統。2. The iron ion implanter according to claim 1, wherein the condensate taken out from a pipe branched from the condensate mother pipe is brought into contact with a carbon steel material for corrosion.
A water supply system of a nuclear power plant, wherein iron ions generated by the corrosion are injected.
原子力発電プラントの給水系統。3. A water supply system for a nuclear power plant according to claim 2, wherein a deaerator is provided in the branched pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60087212A JPH0631815B2 (en) | 1985-04-23 | 1985-04-23 | Nuclear power plant water supply system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60087212A JPH0631815B2 (en) | 1985-04-23 | 1985-04-23 | Nuclear power plant water supply system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61245093A JPS61245093A (en) | 1986-10-31 |
| JPH0631815B2 true JPH0631815B2 (en) | 1994-04-27 |
Family
ID=13908623
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60087212A Expired - Lifetime JPH0631815B2 (en) | 1985-04-23 | 1985-04-23 | Nuclear power plant water supply system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0631815B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0769460B2 (en) * | 1987-04-16 | 1995-07-31 | 株式会社東芝 | Condensate purification equipment at a nuclear power plant |
| JPH079477B2 (en) * | 1987-09-09 | 1995-02-01 | 株式会社日立製作所 | Radioactivity reduction method for nuclear power plant and nuclear power plant |
| JP2808970B2 (en) * | 1992-03-19 | 1998-10-08 | 株式会社日立製作所 | Nuclear power plant, its water quality control method and its operation method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5563798A (en) * | 1978-11-08 | 1980-05-14 | Hitachi Ltd | Corrosion protection method of bwr type power atomic plant |
-
1985
- 1985-04-23 JP JP60087212A patent/JPH0631815B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61245093A (en) | 1986-10-31 |
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