JP2002202393A - Passive reactor shutdown mechanism - Google Patents
Passive reactor shutdown mechanismInfo
- Publication number
- JP2002202393A JP2002202393A JP2000398810A JP2000398810A JP2002202393A JP 2002202393 A JP2002202393 A JP 2002202393A JP 2000398810 A JP2000398810 A JP 2000398810A JP 2000398810 A JP2000398810 A JP 2000398810A JP 2002202393 A JP2002202393 A JP 2002202393A
- Authority
- JP
- Japan
- Prior art keywords
- control rod
- thermal expansion
- passive
- reactor
- drive shaft
- 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.)
- Granted
Links
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
- Y02E30/30—Nuclear fission reactors
Landscapes
- Monitoring And Testing Of Nuclear Reactors (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ヘリウムガスを冷
却材とするガス冷却高速増殖炉の炉停止機構に関し、特
に異常時には受動的に吸収材が炉心に供給されるような
受動的炉停止機構に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor shut-off mechanism for a gas-cooled fast breeder reactor using helium gas as a coolant, and more particularly to a passive reactor shut-off mechanism in which an absorbent is passively supplied to a reactor core in an abnormal situation. About.
【０００２】[0002]
【従来の技術】高速増殖炉ではボロンやカドミウム等の
吸収材を成分とする制御棒によって出力を制御してい
る。原子炉を停止させる際は制御棒を炉心に挿入し、連
鎖反応に必要な中性子を吸収材に吸収させることで反応
を停止する。2. Description of the Related Art In a fast breeder reactor, the output is controlled by a control rod containing an absorbent such as boron or cadmium as a component. When shutting down the reactor, a control rod is inserted into the reactor core and the reaction is stopped by absorbing neutrons necessary for the chain reaction into the absorber.
【０００３】冷却材の循環に障害が生じるなど、炉心冷
却性能が低下する事故が発生した場合、制御棒駆動系に
よって制御棒を炉心に挿入し原子炉スクラムをかける
が、万一制御棒駆動系が正常に働かず制御棒が挿入され
ない場合に備えて受動的炉停止機構が設けられている。
受動的炉停止機構は、炉心冷却性能低下による炉心状態
及びこの雰囲気の変化に基づき受動的に制御棒が炉心に
挿入される方式を採用している。[0003] In the event of an accident that reduces the core cooling performance, such as a failure in the circulation of the coolant, a control rod is inserted into the core by a control rod drive system to apply a reactor scram. A passive furnace shutdown mechanism is provided in case that does not work properly and the control rod is not inserted.
The passive reactor shutdown mechanism employs a system in which a control rod is passively inserted into the reactor core based on a change in the core state due to a decrease in core cooling performance and the atmosphere.
【０００４】ナトリウム冷却高速増殖炉では、図５に示
すような磁石による受動的炉停止機構が利用される。制
御棒駆動機構の末端部に磁石を配し、磁力によって制御
棒を吊り上げて保持している。事故時は炉心から上部へ
流れ出る冷却材が高温になるため、磁石が冷却材に暖め
られて高温化し磁力が低下する。磁力による制御棒の保
持力が低下すると、制御棒が落下して炉心に挿入され、
炉の燃焼が停止する。In a sodium-cooled fast breeder reactor, a passive reactor shutdown mechanism using magnets as shown in FIG. 5 is used. A magnet is arranged at the end of the control rod drive mechanism, and the control rod is lifted and held by magnetic force. At the time of the accident, the coolant flowing upward from the reactor core becomes hot, so the magnet is warmed by the coolant and the temperature rises, reducing the magnetic force. When the holding force of the control rod by magnetic force decreases, the control rod falls and is inserted into the core,
The furnace stops burning.
【０００５】[0005]
【発明が解決しようとする課題】ナトリウム冷却高速増
殖炉では、正常運転時の冷却材温度よりやや高いキュリ
ー点を持つ合金を用いて磁石を形成し、異常時に冷却材
温度が上昇すると合金のキュリー点を超えるようにして
受動的炉停止機構を実現している。しかしヘリウムガス
冷却高速増殖炉では、正常運転時の冷却材の温度が例え
ば鉄のキュリー点約７７０℃を超えた約８５０℃と著し
く高温であるため、磁力を利用するのが困難である。In a sodium-cooled fast breeder reactor, a magnet is formed by using an alloy having a Curie point slightly higher than the coolant temperature during normal operation. A passive reactor shutdown mechanism has been implemented beyond this point. However, in a helium gas-cooled fast breeder reactor, the temperature of the coolant during normal operation is extremely high, for example, about 850 ° C. exceeding the Curie point of iron of about 770 ° C., and it is difficult to utilize magnetic force.
【０００６】また、ナトリウム冷却炉では制御棒駆動機
構が原子炉容器の上面に設置されており、原子炉容器の
蓋に当たる遮蔽プラグを貫通して上方から制御棒を吊り
下げて駆動している。しかし、ガス冷却炉では、燃料変
換時に炉心上部の制御棒駆動機構の退避が必要なため回
転駆動式の遮蔽プラグ構造が必要となるが、冷却性能の
確保のため炉内を約６０ｋｇ／ｃｍ2程度の高圧にして
運転するので、原子炉圧力容器の堅牢性を確保する必要
があり、遮蔽プラグを貫通するタイプの制御棒駆動機構
は望ましくない。そのため、ガス冷却炉では制御棒駆動
機構を炉心の下方に設置し、制御棒を下方から駆動する
方式が採られている。したがって、制御棒を上方から吊
り下げることが前提となっている従来の後備炉停止棒を
直接ガス冷却炉に使用することは困難である。In the sodium-cooled reactor, a control rod drive mechanism is provided on the upper surface of the reactor vessel, and the control rod is suspended from above through a shielding plug that is in contact with a lid of the reactor vessel and driven. However, the gas cooling furnace, although retraction of the core upper part of the control rod drive mechanism shielding plug structure of a rotary drive type is required for required for the fuel conversion, about 60 kg / cm 2 in the furnace in order to ensure the cooling performance Since the reactor is operated at a high pressure, the robustness of the reactor pressure vessel needs to be ensured, and a control rod drive mechanism that penetrates through the shielding plug is not desirable. For this reason, in a gas-cooled furnace, a method is adopted in which a control rod driving mechanism is installed below the core and the control rod is driven from below. Therefore, it is difficult to directly use a conventional post-furnace stop rod on the assumption that the control rod is suspended from above in a gas-cooled furnace.
【０００７】そこで本発明が解決しようとする課題は、
ガス冷却炉でも利用できる受動的炉停止機構を提供する
ことにある。Therefore, the problem to be solved by the present invention is as follows:
An object of the present invention is to provide a passive furnace shut-down mechanism that can be used in a gas-cooled furnace.
【０００８】[0008]
【課題を解決するための手段】上記課題を解決するた
め、本発明の受動的炉停止機構は、制御棒駆動軸と制御
棒と熱膨張具と連結具を備え、制御棒が中性子吸収体か
らなる塊状のものであってほぼ中心に上下に貫通する孔
が開いており、制御棒駆動軸が棒体であり制御棒の孔を
貫通していて上部に制御棒を連結具により連結して支持
しており、冷却材が所定の温度より高温になると熱膨張
具が連結具に作用して連結を解放し制御棒を炉心に落下
させることを特徴とする。In order to solve the above-mentioned problems, a passive furnace shutdown mechanism according to the present invention includes a control rod drive shaft, a control rod, a thermal expansion device, and a connection tool, and the control rod is connected to a neutron absorber. The control rod drive shaft is a rod body and penetrates the hole of the control rod, and the control rod is connected to the upper part by a connecting tool and supported When the temperature of the coolant becomes higher than a predetermined temperature, the thermal expansion tool acts on the connecting tool to release the connection and drop the control rod into the core.
【０００９】本発明の受動的炉停止機構は、下部に制御
棒駆動機構を持つ原子炉で上方に制御棒を引き抜き、制
御棒駆動軸の上端を制御棒に接続して用いる。制御棒駆
動軸と制御棒が連結されて一体となっており、制御棒駆
動機構が制御棒駆動軸を介して制御棒を駆動して炉出力
の調整等を行う。The passive reactor shutdown mechanism of the present invention is used by pulling out a control rod upward in a reactor having a control rod drive mechanism at a lower portion, and connecting an upper end of a control rod drive shaft to the control rod. The control rod drive shaft and the control rod are connected and integrated, and the control rod drive mechanism drives the control rod via the control rod drive shaft to adjust the furnace output and the like.
【００１０】制御棒駆動軸と制御棒は制御棒を支えるの
に必要な強度で連結されており、外力が加わると比較的
容易に連結が破断するように形成されている。熱膨張具
は、熱膨張率が大きい材または大きい材と小さい材との
組み合わせで形成されており、本発明の受動的炉停止機
構を炉内に設置した際に炉心の上方に位置して炉心から
流出した冷却材の温度に応じて膨張収縮するか、または
熱膨張差によって変形する。熱膨張具は、膨張が制御棒
駆動軸と制御棒を分離させる方向に働くように配されて
いる。The control rod drive shaft and the control rod are connected with a strength necessary to support the control rod, and the connection is relatively easily broken when an external force is applied. The thermal expansion device is formed of a material having a high coefficient of thermal expansion or a combination of a material having a large thermal expansion and a material having a small thermal expansion coefficient. Expands or contracts in accordance with the temperature of the coolant flowing out of the chamber, or deforms due to a difference in thermal expansion. The thermal expander is arranged such that expansion acts in a direction to separate the control rod drive shaft and the control rod.
【００１１】熱膨張具周囲の冷却材温度が比較的低い場
合は、熱膨張具が制御棒駆動軸と制御棒を分離させる力
が弱いため制御棒駆動軸が制御棒を支持している。しか
し、例えば冷却材流量低下や反応度挿入等の異常が生じ
るとともに原子炉スクラムに失敗し、冷却材温度が所定
の温度より高温になると熱膨張具の膨張が制御棒駆動軸
と制御棒の連結力を凌駕し、連結を破断する。連結が破
断すると、制御棒が支えを失い、炉心へ落下して炉に負
の反応度を添加する。When the temperature of the coolant around the thermal expander is relatively low, the control rod drive shaft supports the control rod because the thermal expander has a small force to separate the control rod drive shaft from the control rod. However, for example, an abnormality such as a decrease in coolant flow rate or reactivity insertion occurs, and the reactor scram fails.When the coolant temperature becomes higher than a predetermined temperature, the expansion of the thermal expansion device causes the connection between the control rod drive shaft and the control rod. Overpower and break the connection. If the connection breaks, the control rods lose support and fall into the core, adding negative reactivity to the furnace.
【００１２】以上の様に本発明の受動的炉停止機構は、
炉心から流出する冷却材温度の上昇から異常を感知し、
自律的に炉心に負の反応度を添加して炉を停止する。本
発明の受動的炉停止機構は、外部からの制御を必要とせ
ず、物理現象を用いて作動するため、非常に信頼性が高
い。[0012] As described above, the passive furnace shutdown mechanism of the present invention comprises:
Abnormality is detected from the rise in coolant temperature flowing out of the core,
The furnace is shut down by adding a negative reactivity to the core autonomously. The passive furnace shutdown mechanism of the present invention does not require external control and operates using physical phenomena, so that it is very reliable.
【００１３】なお、本発明の受動的炉停止機構は、制御
棒駆動軸の上端に天板を固設し、天板に連結具により制
御棒を釣支し、天板と制御棒の間に熱膨張具を挿入して
温度上昇に従って熱膨張具が制御棒を押圧するように
し、冷却材が所定の温度より高温になると熱膨張具の押
圧力により連結具が損壊して制御棒が炉心に落下するよ
うにするのが設計上好ましい。In the passive furnace stop mechanism of the present invention, a top plate is fixed to the upper end of the control rod drive shaft, the control rod is supported on the top plate by a connecting tool, and the top plate and the control rod are interposed. The thermal expansion device is inserted so that the thermal expansion device presses the control rod in accordance with the temperature rise.When the temperature of the coolant becomes higher than a predetermined temperature, the coupling device is damaged by the pressing force of the thermal expansion device and the control rod is inserted into the core. It is preferable in terms of design to make it fall.
【００１４】本態様の受動的炉停止機構では、熱膨張具
が制御棒駆動軸の天板と制御棒の間に挟み込まれてお
り、炉内が低温の時は天板と制御棒に強い力を及ぼさな
いように干渉しないように形成されている。しかし、炉
に異常が生じて炉から流出する冷却材の温度が高温にな
ると、熱膨張具が膨張して天板と制御棒を圧迫し、天板
と制御棒を乖離させる力を加える。熱膨張が大きくな
り、連結具が制御棒を支えきれなくなると、連結具が破
断し、制御棒が炉心へ落下する。In the passive furnace stopping mechanism of this embodiment, the thermal expansion device is sandwiched between the control rod drive shaft top plate and the control rods, and when the inside of the furnace is at a low temperature, a strong force is applied to the top plate and the control rods. Is formed so as not to cause interference. However, when an abnormality occurs in the furnace and the temperature of the coolant flowing out of the furnace becomes high, the thermal expander expands to compress the top plate and the control rod, and applies a force to separate the top plate and the control rod. When the thermal expansion increases and the connecting tool cannot support the control rod, the connecting tool breaks and the control rod falls into the core.
【００１５】なお、ヘリウムガス冷却高速増殖炉では原
子炉正常運転時の炉内温度が約８５０℃以下であるの
で、本発明の受動的炉停止機構は例えば炉内温度が約１
２００℃程度になると制御棒を炉心へ落下させるように
すると良い。また、本発明の受動的炉停止機構を収容す
る案内管には、制御棒の落下を炉心位置で止めるため、
炉心下端に当たる位置にストッパを設けても良い。In the helium gas-cooled fast breeder reactor, the reactor internal temperature during normal operation of the reactor is about 850 ° C. or less.
When the temperature reaches about 200 ° C., the control rod is preferably dropped into the core. Further, in order to stop the fall of the control rod at the core position, the guide tube accommodating the passive furnace stop mechanism of the present invention,
A stopper may be provided at a position corresponding to the lower end of the core.
【００１６】本形態の受動的炉停止機構では熱膨張具を
天板と制御棒の間に挿入したが、例えば連結具に直接設
けるなど、他の部位に設置することもできる。また熱膨
張具はバイメタルを利用して形成されたものでも良い。
例えば皿バネ状のバイメタルを多数連結して使用する
と、バイメタル単体の変形を総計したものを熱膨張具全
体の膨張として利用できるため非常に便利である。In the passive furnace stop mechanism of this embodiment, the thermal expansion device is inserted between the top plate and the control rod, but it can be installed at another location, for example, directly at the connection device. The thermal expansion device may be formed using a bimetal.
For example, when a large number of bimetals in the form of disc springs are connected and used, the total deformation of the bimetal alone can be used as expansion of the entire thermal expansion device, which is very convenient.
【００１７】また、本形態の受動的炉停止機構では連結
具を物理的に破断することで連結を解放したが、例えば
連結具が突起を受けに係合する形式のものとして連結具
の傍らにバイメタルを配し、周囲が高温になるとバイメ
タルが突起に作用して連結を解放するようにしても良
い。In the passive furnace stop mechanism of the present embodiment, the connection is released by physically breaking the connection. However, for example, the connection is configured to be engaged with the projection to receive the protrusion beside the connection. A bimetal may be provided so that when the surroundings become hot, the bimetal acts on the projection to release the connection.
【００１８】本発明の受動的炉停止機構はヘリウムガス
冷却高速増殖炉に装荷したが、冷却材として炭酸ガス等
を用いる他のガス冷却炉に使用しても良い。高速増殖炉
に限らず、例えば熱中性子炉に使用しても良い。Although the passive reactor shutdown mechanism of the present invention is loaded in a helium gas-cooled fast breeder reactor, it may be used in other gas-cooled reactors using carbon dioxide or the like as a coolant. The present invention is not limited to the fast breeder reactor, and may be used, for example, in a thermal neutron reactor.
【００１９】[0019]
【発明の実施の形態】以下、本発明について実施例に基
づき図面を参照して詳細に説明する。図１は本発明の１
実施例における受動的炉停止機構の上部部分断面図であ
る。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments with reference to the drawings. FIG. 1 shows one embodiment of the present invention.
It is an upper part sectional view of a passive furnace stop mechanism in an example.
【００２０】制御棒駆動軸１の上端に天板２が備わって
おり、天板２に保持構造３が固着されている。制御棒４
の中央に貫通孔が開いており、貫通孔に制御棒駆動軸１
が通されている。制御棒４は上端が結合ピン５によって
保持構造３に連結されて吊り下げられていて、制御棒４
と天板２の間に熱膨張具６が挟み込まれている。制御棒
４はボロンやカドミウム等の吸収材からなっている。制
御棒駆動軸１の下端は図示しない制御棒駆動機構に接続
されている。A top plate 2 is provided at the upper end of the control rod drive shaft 1, and a holding structure 3 is fixed to the top plate 2. Control rod 4
Of the control rod drive shaft 1
Has been passed. The control rod 4 is suspended at its upper end by being connected to the holding structure 3 by a connecting pin 5.
A thermal expansion device 6 is sandwiched between the table and the top plate 2. The control rod 4 is made of an absorbing material such as boron or cadmium. The lower end of the control rod drive shaft 1 is connected to a control rod drive mechanism (not shown).
【００２１】結合ピン５は一端を保持構造３に他端を制
御棒４に固定され制御棒４を釣支している。結合ピン５
は制御棒４の重量を支えるのに必要な強度しか持たず、
制御棒４に自重以外に変位制御型の大きな加重が掛かる
と比較的容易に損壊するように形成されている。熱膨張
具６は熱膨張率の大きい材で形成された棒体であり、炉
内に設置した際は炉心から流出した冷却材に晒されてお
り、冷却材の温度に従って膨張収縮する。炉内が低温の
時は収縮していて天板２と制御棒４に干渉しないが、炉
内が高温になると膨張して天板２と制御棒４を圧迫し、
制御棒４に下方への負荷をかける。The connecting pin 5 has one end fixed to the holding structure 3 and the other end fixed to the control rod 4, and supports the control rod 4. Coupling pin 5
Has only enough strength to support the weight of the control rod 4,
The control rod 4 is formed so as to be relatively easily damaged when a large weight of a displacement control type is applied to the control rod 4 other than its own weight. The thermal expansion device 6 is a rod formed of a material having a high coefficient of thermal expansion. When the thermal expansion device 6 is installed in a furnace, it is exposed to the coolant flowing out of the core, and expands and contracts according to the temperature of the coolant. When the inside of the furnace is cold, it contracts and does not interfere with the top plate 2 and the control rod 4, but when the inside of the furnace becomes high temperature, it expands and presses the top plate 2 and the control rod 4,
A downward load is applied to the control rod 4.
【００２２】本実施例の受動的炉停止機構は、ガス冷却
高速増殖炉に挿入され、制御棒駆動機構に駆動されて原
子炉出力の調整や炉の停止を行う。炉停止時や正常運転
時は、本実施例の受動的炉停止機構は従来の調整棒と同
様に働く。The passive reactor shutdown mechanism of this embodiment is inserted into a gas-cooled fast breeder reactor and driven by a control rod drive mechanism to adjust the reactor power and shut down the reactor. At the time of furnace shutdown or normal operation, the passive furnace shutdown mechanism of the present embodiment works in the same manner as a conventional adjusting rod.
【００２３】冷却材流量低下や反応度挿入等の異常が生
じかつ原子炉スクラムに失敗して炉心が過熱し、炉から
流出する冷却材の温度が高温になると、本実施例の受動
的炉停止機構に備わった熱膨張具６が冷却材の熱を受け
て膨張し、制御棒４を下方へ圧迫する。熱膨張具６付近
を流れる冷却材の温度が著しく上昇し、例えば１２００
℃等設計により決定された所定の温度より高温になる
と、熱膨張具６が制御棒４を圧迫する力が結合ピン５の
耐荷重限度を超え、結合ピン５が損壊する。結合ピン５
が損壊すると制御棒４が制御棒駆動軸１との連結を失
い、制御棒駆動軸１に案内されて炉心へ落下し、炉心に
大きな負の反応度を与えて炉心を確実に停止する。In the case where abnormalities such as a decrease in coolant flow rate or reactivity insertion occur and the reactor scram fails, the core is overheated and the temperature of the coolant flowing out of the furnace becomes high, the passive reactor shutdown of this embodiment is performed. The thermal expansion device 6 provided in the mechanism expands by receiving the heat of the coolant, and presses the control rod 4 downward. The temperature of the coolant flowing near the thermal expansion device 6 rises remarkably, for example, 1200
When the temperature becomes higher than a predetermined temperature determined by design such as ° C., the force of the thermal expansion device 6 pressing on the control rod 4 exceeds the load-bearing limit of the connecting pin 5, and the connecting pin 5 is damaged. Coupling pin 5
When the control rod 4 is damaged, the control rod 4 loses the connection with the control rod drive shaft 1 and is guided by the control rod drive shaft 1 to fall into the core, giving a large negative reactivity to the core and reliably stopping the core.
【００２４】以上の様に本実施例の受動的炉停止機構
は、原子炉炉正常運転時は調整棒として炉出力の調整を
行うが、炉に異常が生じ炉内が高温になると、冷却材温
度の上昇を感知して自己作動的に炉心に制御棒を挿入し
炉を停止する。As described above, the passive reactor shutdown mechanism of this embodiment adjusts the reactor power as an adjusting rod during normal operation of the reactor. When the temperature rise is detected, the control rod is inserted into the core automatically to stop the furnace.
【００２５】なお、結合ピン５は強度を調節するために
切り欠きを設けてもよい。また、本実施例では連結具を
結合ピンとしたが、支持構造３と制御棒４を例えば鎖や
テープ等他の連結具で連結することもできる。The coupling pin 5 may be provided with a notch for adjusting the strength. In this embodiment, the connecting member is a connecting pin. However, the supporting structure 3 and the control rod 4 can be connected by another connecting member such as a chain or a tape.
【００２６】さらに、熱膨張具６は熱膨張率の異なる金
属を組み合わせて形成しても良い。例えば図２に示すよ
うな熱膨張具を用いることもできる。熱膨張率が大きい
金属を板状に形成した膨張板１０と熱膨張率が小さい金
属をかぎ型に形成した連絡板１１を交互に組み合わせて
あり、左端の膨張板１０の上部を天板２に固定してあ
り、右端の膨張板１０の下端が制御棒４に接している。
なお、前述した態様と同様、制御棒４が結合ピン５及び
支持構造３を介して天板２に連結されている。Further, the thermal expansion device 6 may be formed by combining metals having different coefficients of thermal expansion. For example, a thermal expansion device as shown in FIG. 2 can be used. An expansion plate 10 in which a metal having a large thermal expansion coefficient is formed in a plate shape and a connecting plate 11 in which a metal having a low thermal expansion coefficient is formed in a hook shape are alternately combined. The lower end of the rightmost expansion plate 10 is in contact with the control rod 4.
Note that, similarly to the above-described embodiment, the control rod 4 is connected to the top plate 2 via the connecting pin 5 and the support structure 3.
【００２７】周囲が高温になると膨張板１０は大きく膨
張するが、連絡板１１はほとんど膨張しない。本態様の
熱膨張具は膨張板１０の膨張量の和から連絡板１１の膨
張量の和を引いたものが膨張具全体の膨張量になる。し
たがって、膨張板１０の熱膨張率を連絡板１１の熱膨張
率より大幅に大きく形成すると、膨張具が１本の金属棒
である場合より遙かに大きな膨張量を得ることができ便
利である。図では膨張板１０を４枚用いたが、適宜枚数
を増やして膨張量を調整することができる。When the surrounding temperature becomes high, the expansion plate 10 expands greatly, but the communication plate 11 hardly expands. In the thermal expansion device of this embodiment, the expansion amount of the entire expansion device is obtained by subtracting the expansion amount of the connecting plate 11 from the expansion amount of the expansion plate 10. Therefore, if the coefficient of thermal expansion of the expansion plate 10 is formed to be much larger than the coefficient of thermal expansion of the connecting plate 11, a much larger amount of expansion can be obtained than when a single metal rod is used as the expander, which is convenient. . Although four expansion plates 10 are used in the drawing, the expansion amount can be adjusted by appropriately increasing the number of expansion plates.
【００２８】また、熱膨張具６はバイメタルを利用して
形成しても良い。例えば図３に示すような熱膨張具を用
いることもできる。熱膨張率が大きい金属と熱膨張率が
小さい金属を張り合わせた皿バネ状のバイメタル２０を
組み合わせたものであって、上端が天板２に接してお
り、下端は制御板４に接している。本態様の熱膨張具
は、周囲が高温になるとバイメタル２０が湾曲して上下
に大幅に拡幅する。バイメタルの変形率は金属の熱膨張
率より遙かに大きいため、熱膨張を直接用いる熱膨張具
より大きな熱応答を得ることができる。したがって、本
態様の熱膨張具によれば熱設計が非常に容易になる。The thermal expansion device 6 may be formed using a bimetal. For example, a thermal expansion device as shown in FIG. 3 can be used. It is a combination of a disc spring-shaped bimetal 20 in which a metal having a large coefficient of thermal expansion is bonded to a metal having a small coefficient of thermal expansion. The upper end is in contact with the top plate 2, and the lower end is in contact with the control plate 4. In the thermal expansion device of this aspect, when the surroundings become high in temperature, the bimetal 20 bends and widens significantly up and down. Since the deformation rate of the bimetal is much larger than the thermal expansion coefficient of the metal, a larger thermal response can be obtained than a thermal expansion device that directly uses thermal expansion. Therefore, according to the thermal expansion device of this aspect, thermal design becomes very easy.
【００２９】一方熱膨張具６は例えば図４に示したよう
な形式にすることもできる。保持ピン３０がバネ３１に
接続されて制御棒４の上端から横方向へ突出しており、
支持構造３に貫孔３２が開いており、保持ピン３０を貫
孔３２に系合させて制御棒を支持している。保持ピン３
０の先端にはエクステンション３３を介してバイメタル
３４が配されている。バイメタル３４は周囲が高温にな
ると制御棒４側へ湾曲し、エクステンション３３を介し
て保持ピン３０を押して貫孔３２から外し、制御棒４と
支持構造３の連結を解除して制御棒４を落下させる。On the other hand, the thermal expansion device 6 can be of a type as shown in FIG. 4, for example. The holding pin 30 is connected to the spring 31 and projects laterally from the upper end of the control rod 4.
A through hole 32 is formed in the support structure 3, and the control pin is supported by connecting the holding pin 30 to the through hole 32. Holding pin 3
A bimetal 34 is disposed at the leading end of the “0” via an extension 33. The bimetal 34 bends toward the control rod 4 when the surrounding temperature becomes high, pushes the holding pin 30 through the extension 33 to remove it from the through hole 32, releases the connection between the control rod 4 and the support structure 3, and drops the control rod 4. Let it.
【００３０】[0030]
【発明の効果】以上説明した通り本発明の受動的炉停止
機構によれば、冷却材温度の上昇を利用して炉の異常を
感知し受動的に作動して炉を緊急停止することができ
る。As described above, according to the passive furnace shutdown mechanism of the present invention, it is possible to sense the abnormality of the furnace by utilizing the rise in the coolant temperature and to operate the apparatus passively to perform an emergency shutdown of the furnace. .
【図１】本発明の１実施例における受動的炉停止機構の
上部断面図である。FIG. 1 is a top sectional view of a passive furnace shutdown mechanism according to an embodiment of the present invention.
【図２】本発明の１実施例の１態様における受動的炉停
止機構の制御棒駆動軸と制御棒の連結部を示す一部断面
図である。FIG. 2 is a partial cross-sectional view showing a connecting portion between a control rod drive shaft and a control rod of a passive furnace stopping mechanism according to one embodiment of the present invention.
【図３】本発明の１実施例の他の態様における受動的炉
停止機構の制御棒駆動軸と制御棒の連結部を示す一部断
面図である。FIG. 3 is a partial cross-sectional view showing a connecting portion between a control rod drive shaft and a control rod of a passive furnace stopping mechanism according to another embodiment of the present invention.
【図４】本発明の１実施例の他の態様における受動的炉
停止機構の制御棒駆動軸と制御棒の連結部を示す一部断
面図である。FIG. 4 is a partial cross-sectional view showing a connecting portion between a control rod drive shaft and a control rod of a passive furnace stop mechanism according to another embodiment of the present invention.
【図５】従来の受動的炉停止機構の例を示す概念断面図
である。FIG. 5 is a conceptual sectional view showing an example of a conventional passive furnace stopping mechanism.
１ 制御棒駆動軸 ２ 天板 ３ 支持構造 ４ 制御棒 ５ 結合ピン ６ 熱膨張具 １０ 膨張板 １１ 連絡板 ２０ バイメタル ３０ 保持ピン ３１ バネ ３２ 貫孔 ３３ エクステンション ３４ バイメタル REFERENCE SIGNS LIST 1 control rod drive shaft 2 top plate 3 support structure 4 control rod 5 connecting pin 6 thermal expansion device 10 expansion plate 11 communication plate 20 bimetal 30 holding pin 31 spring 32 through hole 33 extension 34 bimetal
Claims (4)
炉に使用する受動的炉停止機構であって、制御棒駆動軸
と制御棒と熱膨張具と連結具を備え、該制御棒が中性子
吸収体からなる塊状のものであってほぼ中心に上下に貫
通する孔が開いており、前記制御棒駆動軸が棒体であり
前記制御棒の孔を貫通していて上部に該制御棒を前記連
結具により連結して支持しており、該冷却材が所定の温
度より高温になると該熱膨張具が前記連結具に作用して
連結を解放し前記制御棒を炉心に落下させることを特徴
とする受動的炉停止機構。1. A passive reactor shutdown mechanism for use in a nuclear reactor having a control rod drive mechanism below a reactor core, comprising a control rod drive shaft, a control rod, a thermal expansion device, and a connector, wherein the control rod is a neutron. A block formed of an absorbent body and having a hole penetrating vertically at substantially the center is opened, and the control rod drive shaft is a rod body, penetrates the hole of the control rod, and the control rod When the temperature of the coolant becomes higher than a predetermined temperature, the thermal expansion tool acts on the connecting tool to release the connection and drop the control rod into the core. Passive furnace shutdown mechanism.
れており、該天板に連結具により前記制御棒が釣支され
ており、該天板と該制御棒の間に前記熱膨張具が挿入さ
れていて温度上昇に従って該熱膨張具が該制御棒を押圧
し、前記冷却材が所定の温度より高温になると該熱膨張
具の押圧力により前記連結具が損壊して前記制御棒を炉
心に落下させることを特徴とする請求項１記載の受動的
炉停止機構。2. A top plate is fixedly provided at an upper end of the control rod drive shaft, and the control rod is supported by a coupling to the top plate, and the control rod is provided between the top plate and the control rod. The thermal expander is inserted and the thermal expander presses the control rod according to a rise in temperature, and when the coolant becomes higher than a predetermined temperature, the pressing force of the thermal expander damages the connecting device and the connecting device is damaged. 2. The passive furnace shutdown mechanism according to claim 1, wherein the control rod is dropped into the core.
成されていることを特徴とする請求項１または２記載の
受動的炉停止機構。3. The passive furnace shutdown mechanism according to claim 1, wherein said thermal expansion device is formed using a bimetal.
するものであって、該連結具の傍らにバイメタルが配さ
れており、前記冷却材が所定の温度より高温になると前
記バイメタルが前記突起に作用し係合を外して連結を解
放することを特徴とする請求項１記載の受動的炉停止機
構。4. The connecting tool engages with and engages with the projection, and a bimetal is arranged beside the connecting tool, and when the temperature of the coolant becomes higher than a predetermined temperature, 2. The passive furnace shut-down mechanism according to claim 1, wherein a bimetal acts on said projection to disengage and release the connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000398810A JP3428963B2 (en) | 2000-12-27 | 2000-12-27 | Passive furnace shutdown mechanism |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000398810A JP3428963B2 (en) | 2000-12-27 | 2000-12-27 | Passive furnace shutdown mechanism |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2002202393A true JP2002202393A (en) | 2002-07-19 |
| JP3428963B2 JP3428963B2 (en) | 2003-07-22 |
Family
ID=18863699
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000398810A Expired - Fee Related JP3428963B2 (en) | 2000-12-27 | 2000-12-27 | Passive furnace shutdown mechanism |
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| Country | Link |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015500986A (en) * | 2011-12-02 | 2015-01-08 | コミッサリア ア レネルジー アトミーク エ オ ゼネルジ ザルタナテイヴ | Device for starting and inserting absorbers and / or moderators into the nuclear fission zone of a nuclear reactor and nuclear fuel assembly comprising such a device |
| JP2017501415A (en) * | 2013-12-31 | 2017-01-12 | ニュースケール パワー エルエルシー | Reactor control rod management |
-
2000
- 2000-12-27 JP JP2000398810A patent/JP3428963B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015500986A (en) * | 2011-12-02 | 2015-01-08 | コミッサリア ア レネルジー アトミーク エ オ ゼネルジ ザルタナテイヴ | Device for starting and inserting absorbers and / or moderators into the nuclear fission zone of a nuclear reactor and nuclear fuel assembly comprising such a device |
| JP2017501415A (en) * | 2013-12-31 | 2017-01-12 | ニュースケール パワー エルエルシー | Reactor control rod management |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3428963B2 (en) | 2003-07-22 |
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