JPS6329240B2 - - Google Patents

Info

Publication number
JPS6329240B2
JPS6329240B2 JP55087898A JP8789880A JPS6329240B2 JP S6329240 B2 JPS6329240 B2 JP S6329240B2 JP 55087898 A JP55087898 A JP 55087898A JP 8789880 A JP8789880 A JP 8789880A JP S6329240 B2 JPS6329240 B2 JP S6329240B2
Authority
JP
Japan
Prior art keywords
accident
reactor
pressure vessel
containment vessel
reactor pressure
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
Application number
JP55087898A
Other languages
Japanese (ja)
Other versions
JPS5713391A (en
Inventor
Masaki Matsumoto
Ryozo Tsuruoka
Tadakazu Nakayama
Tetsuo Horiuchi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP8789880A priority Critical patent/JPS5713391A/en
Publication of JPS5713391A publication Critical patent/JPS5713391A/en
Publication of JPS6329240B2 publication Critical patent/JPS6329240B2/ja
Granted legal-status Critical Current

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

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  • Monitoring And Testing Of Nuclear Reactors (AREA)

Description

【発明の詳細な説明】 本発明は原子炉圧力容器内における事故時の炉
心状況予測装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a system for predicting the state of a reactor core at the time of an accident within a reactor pressure vessel.

一般に冷却材喪失事故時の原子炉格納容器内雰
囲気の線量率は、格納容器内雰囲気放射線モニタ
（以下CAMSと略する）で測定されているが、制
御棒落下事故等の小事故時には、逃し安全弁を通
してわずかの放射線しか放出されないので、
CAMSを用いて事故時の炉心の状況を予測する
ことは困難である。したがつて、これにかわる事
故時の炉心状況予測装置の開発が望まれている。 Generally, the dose rate of the atmosphere inside the reactor containment vessel during a loss of coolant accident is measured using a containment vessel atmosphere radiation monitor (hereinafter abbreviated as CAMS). Only a small amount of radiation is emitted through the
It is difficult to predict the state of the reactor core at the time of an accident using CAMS. Therefore, it is desired to develop an alternative device for predicting the state of the reactor core in the event of an accident.

本発明は上記に鑑みてなされたもので、その目
的とするところは、事故時の炉心状況を適確に予
測することができる事故時の炉心状況予測装置を
提供することにある。 The present invention has been made in view of the above, and an object of the present invention is to provide an apparatus for predicting the state of a reactor core at the time of an accident, which can accurately predict the state of the reactor core at the time of an accident.

本発明の特徴は、原子炉圧力容器上部の外側に
放射線モニタを設置し、この放射線モニタと格納
容器内雰囲気放射線モニタとからの情報を入力と
して事故時炉心状況演算処理装置で必要な演算処
理を行い事故時の炉心状況を予測して表示させる
構成とした点にある。 A feature of the present invention is that a radiation monitor is installed outside the upper part of the reactor pressure vessel, and information from this radiation monitor and the containment vessel atmosphere radiation monitor is input to perform necessary calculation processing in the accident core status calculation processing unit. The key point is that the system is configured to predict and display the core status at the time of an accident.

以下本発明を第１図、第２図に示した実施例お
よび第３図、第４図を用いて詳細に説明する。 The present invention will be explained in detail below with reference to the embodiment shown in FIGS. 1 and 2, and FIGS. 3 and 4.

第１図は本発明の装置の一実施例を示すブロツ
ク図である。第１図において、１は原子炉格納容
器で、原子炉格納容器１の内側で、かつ、原子炉
圧力容器２の上部外側に新しく放射線モニタ３を
設置し、放射線モニタ３からの情報を従来から原
子炉格納容器１の側壁部に設置してあるCAMS
４からの情報とともに、炉心内の状況を予測する
事故時炉心状況予測演算処理装置５に与え、演算
処理装置５で得られた予測結果を表示装置６に表
示させ、操作員に知らせるように構成してある。
なお、第２図は第１図のＡ部拡大図である。 FIG. 1 is a block diagram showing one embodiment of the apparatus of the present invention. In Fig. 1, 1 is the reactor containment vessel, and a new radiation monitor 3 is installed inside the reactor containment vessel 1 and outside the upper part of the reactor pressure vessel 2, and the information from the radiation monitor 3 is transferred from the conventional one. CAMS installed on the side wall of reactor containment vessel 1
4 to a calculation processing unit 5 for predicting the state of the core at the time of an accident, which predicts the situation inside the reactor core, and the prediction result obtained by the calculation processing unit 5 is displayed on a display device 6 to notify the operator. It has been done.
Note that FIG. 2 is an enlarged view of section A in FIG. 1.

制御棒落下事故等の小事故で燃料破損が生じる
と、主蒸気隔離弁（図示せず）が閉鎖した後、原
子炉圧力容器２内の気相部に燃料より放出された
核分裂生成物が滞留する。この核分裂生成物から
の放射線は、上記した放射線モニタ３で連続的に
計測される。 When fuel damage occurs due to a small accident such as a control rod fall, the fission products released by the fuel remain in the gas phase inside the reactor pressure vessel 2 after the main steam isolation valve (not shown) closes. do. Radiation from this fission product is continuously measured by the radiation monitor 3 described above.

また、原子炉圧力容器２内の圧力が高くなる
と、逃し安全弁（図示せず）より圧力容器２内の
放射線を出す雰囲気が原子炉格納容器１へ放出さ
れる。このとき、格納容器１内の雰囲気からの放
射線はCAMS４で連続的に計測される。 Furthermore, when the pressure inside the reactor pressure vessel 2 increases, the radiation-emitting atmosphere inside the pressure vessel 2 is released into the reactor containment vessel 1 from a relief safety valve (not shown). At this time, radiation from the atmosphere inside the containment vessel 1 is continuously measured by the CAMS 4.

次に以上の計測結果にもとづいた事故時炉心状
況予測演算処理装置５での予測演算の原理につい
て説明する。周知のように、計測器の線量率Ｄ
（ｍＲ／hr）は次式によつて与えられる。 Next, the principle of predictive calculation in the accident core state prediction calculation processing device 5 based on the above measurement results will be explained. As is well known, the dose rate D of the measuring instrument
(mR/hr) is given by the following formula.

Ｄ＝D1＋D2＋D3 ………(1) ここに、D1；原子炉圧力容器２内の炉心内か
ら放出される放射線による寄与分（ｍＲ／hr） D2；原子炉圧力容器２内の気相部の核分裂生成
物からの寄与分（ｍＲ／hr） D3；原子炉格納容器１内に放出された核分裂生
成物からの寄与分（ｍＲ／hr） なお、D1は通常時の線量率とほぼ等しいと考
えてよいから、事故時における原子炉圧力容器２
内の放射能濃度は、次の仮定のもとに計算でき
る。 D=D 1 +D 2 +D 3 ......(1) Here, D 1 ; Contribution of radiation emitted from inside the reactor core in the reactor pressure vessel 2 (mR/hr) D 2 ; Reactor pressure vessel 2 Contribution from fission products in the gas phase within reactor containment vessel 1 (mR/hr) D 3 ; Contribution from fission products released into reactor containment vessel 1 (mR/hr) Note that D 1 is normal. It can be considered that the dose rate is almost equal to the dose rate of reactor pressure vessel 2 at the time of the accident.
The radioactivity concentration within can be calculated based on the following assumptions.

(イ) D2≫D3とする。(a) Let D 2 ≫ D 3 .

この関係は事故時初期においては十分成立す
る。 This relationship holds true in the early stages of an accident.

(ロ) 気相部の体積はVR、放射能濃度は一様に
QμCi／cm3であるとする。(b) The volume of the gas phase is V R and the radioactivity concentration is uniform.
Assume that QμCi/ cm3 .

(ハ) 気相部を円柱の体積線源とし、原子炉圧力容
器２の鉄板の厚さをt0cmとする。(c) The gas phase section is assumed to be a cylindrical volume source, and the thickness of the iron plate of the reactor pressure vessel 2 is t 0 cm.

上記の仮定により、原子炉圧力容器２外におけ
る計測地点での放射能濃度Ｑ（μCi／cm3）は次式
により計算できる。 Based on the above assumptions, the radioactivity concentration Q (μCi/cm 3 ) at the measurement point outside the reactor pressure vessel 2 can be calculated using the following formula.

Ｑ＝Ｋ・D2 ………(2) ここに、Ｋ；換算係数（μCi／cm3／ｍＲ／hr） 第３図は放射線モニタ３による一測定例を、第
４図はCAMS４による一測定例を示した線図で
ある。第３図において、Ｄ，D1，D2，D3は、そ
れぞれ(1)式のD1D1、D2、D3に対応している。ま
た、第４図においてCAMS４によつて計測され
る線量率D′は、次式より求まる。 Q=K・D 2 ......(2) Here, K: Conversion coefficient (μCi/cm 3 /mR/hr) Figure 3 shows an example of measurement using Radiation Monitor 3, and Figure 4 shows an example of measurement using CAMS 4. It is a diagram showing an example. In FIG. 3, D, D 1 , D 2 , and D 3 correspond to D 1 D 1 , D 2 , and D 3 in equation (1), respectively. Further, the dose rate D' measured by the CAMS 4 in FIG. 4 is determined from the following equation.

D′＝D4′＋D3′ ………(3) ここに、D4′；原子炉圧力容器２内の核分裂生
成物からの寄与分（ｍＲ／hr） D3′；原子炉格納容器１内に放出された核分裂生
成物からの寄与分（ｍＲ／hr） 原子炉圧力容器２内からの寄与分D4′は、通常
時の線量率にほぼ等しいと考えてよいから、(3)式
からD3′が求まる。このとき、原子炉格納容器１
内は一様な放射能濃度Q′であると仮定すれば、
次式を用いてそれを計算できる。 D′=D 4 ′+D 3 ′ ………(3) Here, D 4 ′; Contribution from fission products in reactor pressure vessel 2 (mR/hr) D 3 ′; Containment vessel 1 Contribution from fission products released into the reactor pressure vessel 2 (mR/hr) Since the contribution from the inside of the reactor pressure vessel 2 D 4 ' can be considered to be approximately equal to the normal dose rate, equation (3) D 3 ′ can be found from At this time, reactor containment vessel 1
Assuming that the radioactivity concentration Q′ is uniform within
It can be calculated using the following formula:

Q′＝K′・D3′ ………(4) ここに、K′；換算係数（μCi／cm3／ｍＲ／hr） 上記の原理を用いて、事故時炉心状況予測演算
処理装置５で、第３図、第４図に示してあるよう
に、各線量率寄与を分離し、原子炉圧力容器２内
の気相部の核分裂生成物による線量率寄与D2よ
りＱを(2)式より求め、また、原子炉格納容器１内
に放出された核分裂生成物による線量率寄与
D3′より格納容器１内における放射能濃度Q′を(4)
式より求める。次に下記により事故時の炉心状況
を予測する。 Q′=K′・D 3 ′ ………(4) Here, K′: Conversion coefficient (μCi/cm 3 /mR/hr) Using the above principle, the calculation processing unit 5 , as shown in Figs. 3 and 4, each dose rate contribution is separated and the dose rate contribution D 2 due to the fission products in the gas phase inside the reactor pressure vessel 2 is expressed as Q by equation (2). Also, the dose rate contribution due to fission products released into the reactor containment vessel 1.
From D 3 ′, the radioactivity concentration Q′ in containment vessel 1 is (4)
Obtained from the formula. Next, predict the core situation at the time of the accident using the following.

(1) 放射線モニタ３により得られた線量率Ｄか
ら、第３図に示すように通常時の放射線レベル
より高くなることより事故を検出し、また、上
記で求めた線量率D3の時間変化より事故の拡
大もしくは事故の縮小を予測する。(1) An accident is detected from the dose rate D obtained by the radiation monitor 3, which is higher than the normal radiation level as shown in Figure 3, and the time change of the dose rate D 3 obtained above. Predict the expansion of accidents or the reduction of accidents.

(2) 線量率D2（ｍＲ／hr）より求まる原子炉圧力
容器１内放射能濃度Q2（μCi／cm3）から事故の
規模、すなわち、燃料破損状況を予測する。一
般に通常時の原子炉圧力容器２上部外側の放射
線レベルは約105ｍＲ／hrであり、制御棒落下
事故時の破損燃料730本の場合は、D2107ｍ
Ｒ／hrとなり、70本程度以上の破損があれば、
燃料破損状況を予測することが可能である。(2) Predict the scale of the accident, that is, the state of fuel damage, from the radioactivity concentration Q 2 (μCi/cm 3 ) in the reactor pressure vessel 1 determined from the dose rate D 2 (mR/hr). Generally, the radiation level outside the upper part of the reactor pressure vessel 2 under normal conditions is about 10 5 mR/hr, and in the case of 730 damaged fuel pieces in a control rod fall accident, the radiation level is D 2 10 7 mR/hr.
R/hr, and if there is damage of about 70 or more,
It is possible to predict fuel failure situations.

(3) 放射線モニタ３とCAMS４とから得られた
情報から、原子炉圧力容器２内気相部の放射能
濃度Q2（μCi／cm3）と原子炉格納容器１内の放
射能濃度Q3′を求め、さらに、格納容器１内へ
の移行割合を次式より求め、 α＝Q3′・V3′／Q2・V2 ………(5) ここに、V3′；格納容器１内気相部体積（cm3） V2；圧力容器２内気相部体積（cm3） この移行割合αの変化からの放射能の拡がり、
ひいては発電所放出を予測する。(3) From the information obtained from the radiation monitor 3 and CAMS 4, determine the radioactivity concentration Q 2 (μCi/cm 3 ) in the gas phase inside the reactor pressure vessel 2 and the radioactivity concentration Q 3 ′ inside the reactor containment vessel 1. Then, calculate the migration rate into the containment vessel 1 using the following formula, α=Q 3 ′・V 3 ′/Q 2・V 2 ………(5) Here, V 3 ′; Containment vessel 1 Internal gas phase volume (cm 3 ) V 2 ; Volume of internal gas phase in pressure vessel 2 (cm 3 ) Spread of radioactivity from changes in this transfer ratio α,
In turn, predict power plant emissions.

なお、上記により明確になつた事故の発生、事
故の拡大もしくは事故の縮小予測結果、燃料破損
状況および放射能の拡がり予測結果を事故時炉心
状況予測演算処理装置５から表示装置６に出力
し、表示装置６に表示して運転員に知らせ、事故
後の適切な処置の示唆を与えるようにしてある。 In addition, the results of predicting the occurrence of an accident, the expansion of the accident, or the reduction of the accident, the fuel damage situation, and the spread of radioactivity that have become clear as described above are output from the calculation processing device 5 for predicting the core situation at the time of the accident to the display device 6. The information is displayed on the display device 6 to notify the operator and provide suggestions for appropriate measures to be taken after the accident.

以上説明したように、本発明によれば、事故時
の炉心状況を適確に予測して表示することができ
るという効果がある。 As explained above, according to the present invention, there is an effect that the reactor core status at the time of an accident can be accurately predicted and displayed.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の事故時の炉心状況予測装置の
一実施例を示すブロツク図、第２図は第１図のＡ
部拡大図、第３図、第４図は第１図の事故時炉心
状況予測演算処理装置により放射線モニタと
CAMSによる測定結果から各線量率寄与を分離
した結果の一例をそれぞれ示す線図である。 １……原子炉格納容器、２……原子炉圧力容
器、３……放射線モニタ、４……CAMS、５…
…事故時炉心状況予測演算処理装置、６……表示
装置。 FIG. 1 is a block diagram showing an embodiment of the system for predicting core status at the time of an accident according to the present invention, and FIG.
Enlarged views of the area, Figures 3 and 4 show radiation monitors and processors used to predict the core situation at the time of the accident shown in Figure 1.
FIG. 3 is a diagram showing an example of the results of separating each dose rate contribution from the measurement results by CAMS. 1... Reactor containment vessel, 2... Reactor pressure vessel, 3... Radiation monitor, 4... CAMS, 5...
...Arithmetic processing device for predicting core status at the time of accident, 6...Display device.

Claims (1)

【特許請求の範囲】[Claims] １ 原子炉圧力容器上部の外部に設置した放射線
モニタと、原子炉格納容器の側壁部に設置した格
納容器内雰囲気放射線モニタと、前記二つの放射
線モニタからの情報を入力として必要な演算処理
を行つて前記原子炉圧力容器内の炉心状況を予測
する事故時炉心状況演算処理装置と、該演算処理
装置での予測結果を表示する表示装置とからなる
ことを特徴とする事故時の炉心状況予測装置。1. A radiation monitor installed outside the upper part of the reactor pressure vessel, and an atmosphere radiation monitor inside the containment vessel installed on the side wall of the reactor containment vessel, and the necessary arithmetic processing is performed using information from the two radiation monitors as input. An accident core condition prediction device comprising: an accident core condition arithmetic processing device for predicting the core condition in the reactor pressure vessel; and a display device for displaying the prediction result of the arithmetic processing device. .
JP8789880A 1980-06-30 1980-06-30 Device for forecasting core state at accident Granted JPS5713391A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8789880A JPS5713391A (en) 1980-06-30 1980-06-30 Device for forecasting core state at accident

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8789880A JPS5713391A (en) 1980-06-30 1980-06-30 Device for forecasting core state at accident

Publications (2)

Publication Number Publication Date
JPS5713391A JPS5713391A (en) 1982-01-23
JPS6329240B2 true JPS6329240B2 (en) 1988-06-13

Family

ID=13927706

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8789880A Granted JPS5713391A (en) 1980-06-30 1980-06-30 Device for forecasting core state at accident

Country Status (1)

Country Link
JP (1) JPS5713391A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2858208B2 (en) * 1994-04-20 1999-02-17 本田技研工業株式会社 Cylinder block

Also Published As

Publication number Publication date
JPS5713391A (en) 1982-01-23

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