JP2003149391A - Filler for burying radioactive waste - Google Patents
Filler for burying radioactive wasteInfo
- Publication number
- JP2003149391A JP2003149391A JP2001345353A JP2001345353A JP2003149391A JP 2003149391 A JP2003149391 A JP 2003149391A JP 2001345353 A JP2001345353 A JP 2001345353A JP 2001345353 A JP2001345353 A JP 2001345353A JP 2003149391 A JP2003149391 A JP 2003149391A
- Authority
- JP
- Japan
- Prior art keywords
- radioactive waste
- volcanic glass
- burying
- bentonite
- filling material
- 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
Landscapes
- Processing Of Solid Wastes (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、使用済核燃料の再
処理工程において生じる放射性廃棄物などを地下深部に
埋設するいわゆる地層処分に関連し、特にこの地層処分
に際して使用される埋め戻し材および緩衝材に関するも
のである。なお、本発明の説明において、便宜上、埋め
戻し材と緩衝材を含めて充填材と云う。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to so-called geological disposal for burying radioactive wastes, etc. generated in the reprocessing step of spent nuclear fuel in a deep underground area, and particularly to backfill material and buffer used for this geological disposal. It concerns materials. In the description of the present invention, the backfill material and the cushioning material are collectively referred to as a filler for convenience.
【０００２】[0002]
【従来の技術】使用済核燃料の再処理工程から発生する
高レベル放射性廃棄物の処分方法として、廃棄物をガラ
スに溶融してガラス固化体とし、これを地下深部に埋設
して処分する計画が進められている。現在考えられてい
る高レベル放射性廃棄物処分場は地上施設と地下施設に
よって構成されている。地上施設と地下施設は立坑や斜
坑などによって接続され、地下施設には処分坑道が掘削
されており、この坑道に放射性廃棄物が埋設される。廃
棄物の定置方式としては坑道横置き方式と処分孔縦置き
方式があり、処分後は坑道を埋め戻して地下施設を閉鎖
する。2. Description of the Related Art As a method of disposing of high-level radioactive waste generated from the reprocessing process of spent nuclear fuel, there is a plan to dispose of the waste by melting it into glass to form a vitrified solid, which is buried deep underground. It is being advanced. The high-level radioactive waste disposal site currently considered is composed of aboveground facilities and underground facilities. Ground facilities and underground facilities are connected by vertical shafts and inclined shafts, and underground tunnels have excavated disposal tunnels, and radioactive wastes are buried in these tunnels. There are two types of waste emplacement method: horizontal tunnel method and vertical disposal hole method. After disposal, the underground tunnel is refilled and underground facility is closed.
【０００３】上記廃棄物を安全に隔離するための埋設方
法として、放射性廃棄物のガラス固化体をキャニスター
で囲んで金属製収納容器(オーバパック)に封入し、さら
にこの収納容器を緩衝材で包んで人工バリアを形成し、
坑道は埋め戻し材によって充填し、これを地下深部の地
層が囲む天然バリアからなる多重バリアシステムを構築
している。As a burial method for safely isolating the above-mentioned waste, a vitrified solid body of radioactive waste is enclosed in a canister and enclosed in a metal storage container (overpack), and this storage container is further wrapped with a cushioning material. To form an artificial barrier,
The tunnel is filled with backfill material, and a multi-barrier system consisting of a natural barrier surrounded by deep underground formation is constructed.
【０００４】これらの緩衝材および埋め戻し材は、地下
水の侵入を抑止する止水機能と、将来、放射性核種が地
下水中に漏洩したときに核種を吸着してその移行を阻止
する吸着機能を有することが要求され、現在、緩衝材と
しては珪砂を混合したベントナイトが提唱されており、
また埋め戻し材としてはベントナイトと掘削土の混合材
が有力視され、それらの改良も進められている（例え
ば、特開平7−270597号公報など）。These cushioning materials and backfilling materials have a water-stopping function for suppressing the intrusion of groundwater and an adsorbing function for adsorbing radionuclides to prevent their migration when they leak into groundwater in the future. However, bentonite mixed with silica sand has been proposed as a cushioning material.
Further, as a backfill material, a mixed material of bentonite and excavated soil is considered to be promising, and improvements thereof are being made (for example, JP-A-7-270597).
【０００５】[0005]
【発明が解決しようとする課題】従来のベントナイトを
用いた緩衝材や埋め戻しは、ベントナイトの主成分であ
るスメクタイトが熱によってイライトに変質し、その性
能が劣化する可能性がある。また、大量のベントナイト
を必要とするので、これに代わる材料を確保できれば材
料の選択範囲を広げることができる。本発明はベントナ
イトを主体とした緩衝材、およびこれを用いた埋め戻し
材について、従来の上記問題を解決したものであり、ベ
ントナイトの代替材料として火山ガラスに注目し、これ
をベントナイトに混合して用いることによって優れた放
射性廃棄物埋設用充填材を達成したものである。In the conventional cushioning material and backfilling using bentonite, smectite, which is the main component of bentonite, may be transformed into illite by heat and its performance may be deteriorated. In addition, since a large amount of bentonite is required, if a substitute material can be secured, the selection range of the material can be expanded. The present invention is a cushioning material mainly composed of bentonite, and a backfill material using the same, which solves the above-mentioned conventional problems, paying attention to volcanic glass as a substitute material for bentonite, and mixing it with bentonite. It has achieved an excellent filling material for radioactive waste by using it.
【０００６】[0006]
【課題を解決する手段】本発明によれば以下の構成から
なる放射性廃棄物埋設用充填材が提供される。
（１）放射性廃薬物を地下に埋設する際に用いる緩衝材
または埋め戻し材であって、陽イオン交換性の膨張型粘
土鉱物と微細なクラックを有する火山ガラスとを混合し
てなることを特徴とする放射性廃棄物埋設用充填材。
（２）掘削残土と、陽イオン交換性膨張型粘土鉱物およ
び微細なクラックを有する火山ガラスとを混合してなる
ことを特徴とする放射性廃棄物埋設用充填材。
（３）火山ガラスと共に鉱物質微粉末を含有する上記
(1)または(2)の放射性廃棄物埋設用充填材。
（４）陽イオン交換性膨張型粘土鉱物がベントナイト、
火山ガラスが溶結凝灰岩粉、鉱物質微粉末がフライアッ
シュである上記(1)、(2)または(3)の放射性廃棄物埋設用
充填材。
（５）ベントナイトに対する火山ガラスの重量比が５０
〜６００％である上記(1)〜(4)の何れかに記載する放射
性廃棄物埋設用充填材。
（６）掘削残土に対するベントナイトと火山ガラスの混
合材の重量比が２５〜４６％である上記(1)〜(5)の何れ
かに記載する放射性廃棄物埋設用充填材。According to the present invention, there is provided a radioactive waste burying filler having the following constitution. (1) A buffer material or backfill material used when burying radioactive waste chemicals underground, characterized by mixing cation-exchangeable expansive clay minerals and volcanic glass having fine cracks Filling material for burying radioactive waste. (2) A filling material for burying radioactive waste, which is obtained by mixing excavated soil with cation-exchange expansive clay mineral and volcanic glass having fine cracks. (3) Above containing fine powder of minerals together with volcanic glass
The filling material for burying radioactive waste according to (1) or (2). (4) The cation exchange expandable clay mineral is bentonite,
The filler for burying radioactive waste according to (1), (2) or (3) above, wherein the volcanic glass is welded tuff powder and the fine mineral powder is fly ash. (5) The weight ratio of volcanic glass to bentonite is 50.
The filling material for burying radioactive waste according to any one of (1) to (4) above, which is ˜600%. (6) The filling material for burying radioactive waste according to any one of (1) to (5) above, wherein the weight ratio of the mixed material of bentonite and volcanic glass to the excavated soil is 25 to 46%.
【０００７】[0007]
【発明の実施の形態】以下、本発明を実施形態に基づい
て具体的に説明する。本発明の放射性廃棄物埋設用充填
材は、陽イオン交換性の膨張型粘土鉱物と微細なクラッ
クを有する火山ガラスとを混合してなることを特徴とす
るものであり、また、この混合材料を掘削残土に混合し
てなることを特徴とするものである。陽イオン交換性の
膨張型粘土鉱物と火山ガラスを混合した混合材料は緩衝
材として好適であり、この混合材料を掘削残土に混合し
たものは埋め戻し材として好適である。BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below based on embodiments. The radioactive waste burial filler of the present invention is characterized by comprising a mixture of a cation-exchangeable expansive clay mineral and a volcanic glass having fine cracks. It is characterized by being mixed with excavated soil. A mixed material obtained by mixing cation exchangeable expansive clay mineral and volcanic glass is suitable as a buffer material, and a mixed material obtained by mixing this mixed material with excavated soil is suitable as a backfill material.
【０００８】本発明の充填材において、陽イオン交換性
膨張型粘土鉱物とはベントナイトに代表される粘土鉱物
である。この粘土鉱物は地下水等を吸収して膨張し、埋
設環境の隙間を塞いで止水機能を発揮する。さらに、そ
の陽イオン交換性によって放射性核種を吸着し、その拡
散を防止する。この粘土鉱物はベントナイトを単独に用
いてもよく、他の同種の粘土鉱物や焼成したバーミキュ
ウライトなどを混合して使用してもよい。In the filler of the present invention, the cation-exchangeable expansive clay mineral is a clay mineral represented by bentonite. This clay mineral absorbs groundwater and expands, filling the gaps in the buried environment and exerting a water blocking function. Furthermore, its cation exchange property adsorbs radionuclides and prevents their diffusion. Bentonite may be used alone as the clay mineral, or other clay minerals of the same kind or burned vermiculite may be mixed and used.
【０００９】本発明の充填材は上記粘土鉱物と共に火山
ガラスを含有する。ここで云う火山ガラスとは地熱を受
けてスメクタイトを主成分とする変質鉱物を生成する鉱
物である。従って、通常の火山ガラスのほかに上記粘土
鉱物を生成する鉱物を含む。この火山ガラスを多く含む
岩石として火砕流堆積物、火砕岩、泥岩、溶結凝灰岩な
どが挙げられる。火山ガラスは平均粒径０.１mm以下、
好ましくは２００メッシュ以下の微粉が適当であり、さら
に、本発明の火山ガラスは微細なクラックを有するもの
である。微細なクラックを有することにより、地熱を受
けて変質鉱物を生じやすく、充填材としての効果が向上
する。微細なクラックを有するように火山ガラスを水冷
破砕等の方法によってクラッシュして用いると良い。The filler of the present invention contains volcanic glass together with the above clay minerals. The volcanic glass referred to here is a mineral that undergoes geothermal heat to produce altered minerals whose main component is smectite. Therefore, in addition to ordinary volcanic glass, it includes minerals that produce the above clay minerals. Pyroclastic flow deposits, pyroclastic rocks, mudstone, welded tuff, etc. are mentioned as rocks containing a large amount of this volcanic glass. Volcanic glass has an average particle size of 0.1 mm or less,
A fine powder of 200 mesh or less is suitable, and the volcanic glass of the present invention has fine cracks. Due to the presence of fine cracks, alteration minerals are easily generated by receiving geothermal heat, and the effect as a filler is improved. It is recommended that the volcanic glass be crashed by a method such as water-cooled crushing so as to have fine cracks and used.
【００１０】火山ガラスのベントナイト等の粘土鉱物に
対する量比は５０〜６００％が適当である。火山ガラス
の混合量がこの範囲より少ないと火山ガラスを用いた効
果が不十分であり、一方、火山ガラスをこの範囲より多
く混合すると相対的にベントナイト等の量が少なくなる
ので、埋設初期に火山ガラスが粘土鉱物に変質するまで
の間、充填材の透水係数がやや大きくなる。A suitable amount ratio of volcanic glass to clay minerals such as bentonite is 50 to 600%. If the amount of volcanic glass mixed is less than this range, the effect of using volcanic glass is insufficient.On the other hand, if the amount of volcanic glass mixed with more than this range is relatively small, the amount of bentonite, etc. decreases relatively. The permeability coefficient of the filler is slightly increased until the glass is transformed into a clay mineral.
【００１１】火山ガラスと共に鉱物質微粉末を混合して
も良い。鉱物質微粉末としてはフライアッシュ等を用い
ることができる。フライアッシュ等の混合量は火山ガラ
スに対し重量比で５０〜２００％が好ましい。フライア
ッシュ等の混合量がこれより多いと火山ガラスを用いた
効果が低下するので適当ではない。フライアッシュを混
合することによって充填材（緩衝材ないし埋め戻し材）
を増量することができ、しかも止水機能等は実施的に低
下しないので施工範囲を広げることができる。Fine mineral powder may be mixed with the volcanic glass. Fly ash or the like can be used as the fine mineral powder. The mixing amount of fly ash or the like is preferably 50 to 200% by weight with respect to the volcanic glass. If the amount of fly ash or the like mixed is larger than this, the effect of using volcanic glass is reduced, so this is not suitable. Filler (buffer or backfill) by mixing fly ash
Can be increased, and since the water-stopping function and the like do not actually decrease, the construction range can be expanded.
【００１２】ベントナイト等と火山ガラスを混合したも
の（火山ガラス混合材料）は緩衝材として好適であり、
さらに、この火山ガラス混合材料を掘削残土に混合した
ものは埋め戻し材として好適である。この埋め戻し材の
場合、掘削残土に対する火山ガラス混合材料の重量比は
２５〜４６％が適当である。火山ガラス混合材料の量が
これより多いと経済的でない。また、火山ガラス混合材
の量がこれより少ないと止水機構や吸着機能が不十分に
なる。A mixture of bentonite and the like and volcanic glass (volcanic glass mixed material) is suitable as a cushioning material,
Further, a mixture of this volcanic glass mixed material with excavated soil is suitable as a backfill material. In the case of this backfill material, the weight ratio of the volcanic glass mixed material to the excavated soil is appropriately 25 to 46%. Larger amounts of volcanic glass mixed material are not economical. Further, if the amount of the volcanic glass mixed material is less than this, the water blocking mechanism and the adsorption function become insufficient.
【００１３】[0013]
【実施例】〔実施例１〕火山ガラスの調製
二種類の火山ガラス（試料Ａ、試料Ｂ）を用意した。試
料Ａは流紋岩質溶結凝灰岩中の暗緑色の火山ガラス（Si
O2含有比71％）であり、試料Ｂはデイサイト質溶結凝灰
岩中の黒色の火山ガラス（SiO2含有比65％）である。こ
れらの溶結凝灰岩をハンマーで粉砕し、火山ガラスのみ
を選別した。選別した火山ガラスを２００メッシュ程度に粉
砕した。更に、これら試料の一部を水冷破砕処理した。
水冷破砕法は、まず試料を金属容器に封入し、オーブン
で９００℃に加熱し、３時間その温度を維持した。これ
を１５℃の水槽に入れて急冷した。次に、これらの試料
を２００メッシュの篩にかけて粒度調整を行った。水冷破砕
処理した火山ガラス（No.A-1、No.B-1）と水冷破砕処理
しないもの（No.A-0、No.B-0）を顕微鏡で観察したとこ
ろ、水冷破砕処理したものには微細な魚鱗状の多数のク
ラックが形成されていることが確認された。Examples [Example 1] Preparation of volcanic glass Two kinds of volcanic glass (Sample A and Sample B) were prepared. Sample A is a dark green volcanic glass (Si in rhyolite welded tuff).
The O 2 content ratio is 71%), and the sample B is black volcanic glass in the dacitic welded tuff (SiO 2 content ratio 65%). These welded tuffs were crushed with a hammer and only volcanic glass was selected. The selected volcanic glass was crushed to about 200 mesh. Further, a part of these samples was water-cooled and crushed.
In the water-cooled crushing method, the sample was first sealed in a metal container, heated to 900 ° C. in an oven, and maintained at that temperature for 3 hours. This was put in a water tank at 15 ° C. and rapidly cooled. Next, these samples were passed through a 200-mesh sieve to adjust the particle size. The water-cooled shattered volcanic glass (No.A-1, No.B-1) and the non-water-cooled shattered glass (No.A-0, No.B-0) were observed under a microscope. It was confirmed that a large number of fine fish scale-like cracks were formed in the.
【００１４】〔実施例２〕火山ガラスの変質処理
実施例１で得た４種類の火山ガラス（No.A-1、No.A-1、
No.B-0、No.B-1）を１００℃に加熱して変質を確認し
た。試験方法は、まず火山ガラス１００ｇと脱イオン処
理した蒸留水１００mlとをテフロン（登録商標）製反応
容器に密封し、１００℃に加熱して所定日数（30日、60
日、90日、120日、150日、180日）保持し、水熱反応を
行わせた。各試料のＸ線回折試験によって生成鉱物を同
定し、ベントナイトの主要成分であるスメクタイトの生
成を確認した。この結果を反応期間と共に表１に示し
た。何れの試料も９０日後には粘土化してスメクタイト
が生成しており、水冷破砕処理によって微細なクラック
を形成したものはさらに早く６０日経過後からスメクタ
イトが生成していることが確認された。この粘土化は岩
質による明瞭な差は認められなかった。[ Example 2] Alteration treatment of volcanic glass Four types of volcanic glass (No.A-1, No.A-1,
No.B-0 and No.B-1) were heated to 100 ° C. to confirm alteration. The test method is as follows. First, 100 g of volcanic glass and 100 ml of deionized distilled water are sealed in a Teflon (registered trademark) reaction container, heated to 100 ° C., and kept for a predetermined number of days (30 days, 60 days).
Day, 90 days, 120 days, 150 days, 180 days), and hydrothermal reaction was performed. The produced mineral was identified by the X-ray diffraction test of each sample, and the production of smectite, which is the main component of bentonite, was confirmed. The results are shown in Table 1 together with the reaction period. It was confirmed that after 90 days, all the samples were clayed to form smectites, and that those having fine cracks formed by the water-cooling crushing treatment had smectites formed even after 60 days. This clay formation did not show a clear difference due to the lithology.
【００１５】[0015]
【表１】 [Table 1]
【００１６】〔実施例３〕埋め戻し材の調製
Ａ種火山ガラスについて、破砕処理せずに変質していな
いもの(No.A-0-0)、破砕処理して変質していないもの(N
o.A-1-0)、破砕処理して変質しているもの(No.A-1-1)の
３種類、Ｂ種火山ガラスについて、破砕処理せずに変質
していないもの(No.B-0-0)、破砕処理して変質していな
いもの(No.B-1-0)、破砕処理して変質しているもの(No.
B-1-1)の３種類を用い、これらの火山ガラスと、模擬掘
削残土、およびベントナイトをそれぞれ表２に示す割合
で混合して模擬埋め戻し材を調製した。掘削残土は礫(J
ISA 5005の砕石)と珪砂を等量混合したものを使用し
た。ベントナイトはクニゲルV1(商品名)を用いた。これ
らの試料をカラムに充填して透水試験に供した。透水試
験は、カラムの乾燥密度を１.６g/cm3とし、このカラム
に蒸留水が自然に浸透するまで加えてビニールで密封
し、１００℃の温度条件下で１２０日間放置した。次
に、調製した混合物(模擬埋め戻し材)をカラムに乾燥密
度１.６g/cm3で充填し、このカラムに大気圧中で蒸留水
を流し、規格(JIS A1218-1977)に規定される変水位透水
試験法により透水係数を測定した。その結果を表２に示
した。[ Example 3] Preparation of backfill material Regarding the type A volcanic glass, one that has not been altered without crushing treatment (No. A-0-0) and one that has not been altered by crushing treatment (N
oA-1-0), three types that have been altered by crushing treatment (No.A-1-1), and B type volcanic glass that has not been altered without crushing treatment (No.B- 0-0), those that have not been altered by crushing (No. B-1-0), those that have been altered by crushing (No. B-1-0)
Using three types of B-1-1), these volcanic glasses, simulated excavated soil and bentonite were mixed at the ratios shown in Table 2 to prepare simulated backfill materials. Remaining excavated soil is gravel (J
ISA 5005 crushed stone) and silica sand were mixed in equal amounts. As the bentonite, Kunigel V1 (trade name) was used. These samples were packed in a column and subjected to a water permeability test. In the water permeability test, the dry density of the column was set to 1.6 g / cm 3 , distilled water was added to the column until it naturally permeated, the column was sealed with vinyl, and the column was allowed to stand at 100 ° C. for 120 days. Next, the prepared mixture (simulated backfill material) was packed in a column at a dry density of 1.6 g / cm 3 , and distilled water was allowed to flow in this column at atmospheric pressure, as specified in the standard (JIS A1218-1977). The permeability coefficient was measured by the water level permeability test method. The results are shown in Table 2.
【００１７】表２の結果から明らかなように、火山ガラ
スを混合した試料(No.1〜10)は何れも従来のベントナイ
トのみの火山ガラス未混合の比較試料(No.11)に比べて
透水係数が同程度であり、従来の埋め戻し材と同等の止
水性能を有することが確認された。また、水冷破砕処理
によって微細なクラックを形成した試料は、破砕処理せ
ずにクラックの無い試料に比べて何れも止水性能が向上
しており、さらに水熱反応によってベントナイトの主要
成分であるスメクタイトが生成しているものは止水性能
がいっそう向上していることが確認された。また、火山
ガラスの混合量は５〜３０重量％が好ましく、ベントナ
イトの混合量は５〜１０重量％が適当であることが判
る。As is clear from the results of Table 2, the samples mixed with volcanic glass (Nos. 1 to 10) are more permeable to water than the comparative sample (No. 11) not mixed with conventional bentonite only volcanic glass. It was confirmed that the coefficients are similar and that they have the same waterproof performance as the conventional backfill material. In addition, the samples with fine cracks formed by the water-cooled crushing treatment have improved water-stopping performance compared to the samples without cracking without the crushing treatment, and the smectite, which is the main component of bentonite due to hydrothermal reaction. It was confirmed that the water-blocking performance was further improved. Further, it is understood that the mixing amount of volcanic glass is preferably 5 to 30% by weight, and the mixing amount of bentonite is appropriately 5 to 10% by weight.
【００１８】[0018]
【表２】 [Table 2]
【００１９】〔実施例４〕埋め戻し材の調製
実施例３と同様の火山ガラス、模擬掘削残土、ベントナ
イト、およびフライアッシュを表３に示す量比に従って
混合し、埋め戻し材を調製した。この透水性を測定して
表３に示した。表３の結果から明らかなように、フライ
アッシュを混合したものはフライアッシュ未混合のもの
と同等の透水性を有しており、埋め戻し材として好適で
あることが確認された。[ Example 4] Preparation of backfill material Volcanic glass, simulated excavated soil, bentonite, and fly ash similar to those in Example 3 were mixed according to the quantitative ratio shown in Table 3 to prepare a backfill material. The water permeability was measured and is shown in Table 3. As is clear from the results in Table 3, it was confirmed that the one mixed with fly ash had the same water permeability as the one not mixed with fly ash, and was suitable as a backfill material.
【００２０】[0020]
【表３】 [Table 3]
【００２１】〔実施例５〕模擬埋め戻し材によるＣｓの
吸着比較試験
表４に示す３種の埋め戻し材について、放射性廃棄物中
に含まれている放射性核種の代表的核種である137Ｃｓ
の分配係数を次式(１)に従って測定した。
分配係数＝固相中のＣｓ濃度／液相中のＣｓ濃度・・・（１）
まず、137Ｃｓ濃度が５００Bq/mlおよび塩化カルシウム
濃度０.１モル/lの溶液を用意し、この溶液に塩酸と水酸
化カルシウムを適宜添加し、ｐＨ２・７・１２に調製し
た。これらのｐＨの異なる４種類の溶液１０mlに対して
表４に示す埋め戻し材試料１ｇを接触させ、２４時間経
過後に固液分離し、液中の137Ｃｓ濃度を測定し、次式
(２)に従って分配係数を算出した。式中、Ｋｄは埋め戻
し材試料の分配係数、Ｃｏは137Ｃｓの初期濃度(cpm/m
l)、Ｃtは２４時間経過後の液中の 137Ｃｓ濃度(cpm/m
l)、Ｖは液相の体積(ml)、Ｓは固相の重さ(g)である。
この結果を表４に示した。また、表１の比較試料(No.1
1)についても同様の測定を行った。表４から明らかなよ
うに、火山ガラスを含む試料はこれを含まない試料と同
等の137Ｃｓ吸着性能を有することが確認された。
Ｋｄ＝｛（Ｃ0−Ｃt）／Ｓ｝／（Ｃt／Ｖ）・・・・・（２）[0021][Example 5] of Cs by simulated backfilling material
Adsorption comparison test
Regarding the three types of backfill materials shown in Table 4, in radioactive waste
Is a representative radionuclide contained in137Cs
Partition coefficient was measured according to the following equation (1).
Partition coefficient = Cs concentration in solid phase / Cs concentration in liquid phase (1)
First,137Cs concentration is 500 Bq / ml and calcium chloride
Prepare a solution with a concentration of 0.1 mol / l and add hydrochloric acid and hydroxy acid to this solution.
Adjust the pH to 2 ・ 7 ・ 12 by adding calcium chloride appropriately.
It was For 10 ml of these 4 different solutions
1 g of the backfill material sample shown in Table 4 was contacted, and after 24 hours
Solid-liquid separation after137Measure the Cs concentration and use the following formula
The distribution coefficient was calculated according to (2). In the formula, Kd is backfilled
Partition coefficient of sushi material sample, Co is137Initial concentration of Cs (cpm / m
l), CtIs in the liquid after 24 hours 137Cs concentration (cpm / m
l) and V are liquid phase volumes (ml), and S is solid phase weight (g).
The results are shown in Table 4. In addition, the comparative sample in Table 1 (No. 1
The same measurement was performed for 1). It ’s clear from Table 4.
As such, the sample containing volcanic glass is the same as the sample not containing it.
Etc.137It was confirmed to have Cs adsorption performance.
Kd = {(C0-Ct) / S} / (Ct/ V) (2)
【００２２】[0022]
【表４】 [Table 4]
【００２３】[0023]
【発明の効果】本発明の放射性廃棄物埋設用充填材は、
ベントナイトに代表される陽イオン交換性膨張型粘土鉱
物に火山ガラスを混合したものであり、またこの混合物
を掘削残土に混合したものである。放射性廃棄物を埋設
した処分場は人工地熱系環境下にあると考えられ、一例
として、埋設場所の地熱が数十年で１００℃程度に上昇
し、その後、次第に低下して一万年後には５０℃程度に
なると考えられている。この処分場が深部地下水によっ
て冠水すると廃棄物の放熱によって地下水が加熱されて
熱水になる。本発明の充填材は、埋設後にこの地熱によ
って充填材の火山ガラスがスメクタイトを主体とする変
質鉱物を生成して変質帯バリアを形成し、これが人工バ
リアと天然バリアの多重バリアを補強するので、放射性
廃棄物埋設用充填材として高い信頼性を有する。The filling material for burying radioactive waste of the present invention is
It is a mixture of cation-exchangeable expansive clay mineral represented by bentonite with volcanic glass, and this mixture is mixed with excavated soil. The disposal site where the radioactive waste is buried is considered to be in an artificial geothermal environment, and as an example, the geothermal heat at the disposal site rises to about 100 ° C in several decades, and then gradually declines after 10,000 years. It is considered to be about 50 ° C. When this disposal site is flooded with deep groundwater, the wastewater is radiated to heat the groundwater to become hot water. The filling material of the present invention, after burying, the volcanic glass of the filling material generates altered minerals mainly composed of smectite by this geothermal heat to form an altered zone barrier, which reinforces the multiple barriers of the artificial barrier and the natural barrier. It has high reliability as a filling material for burying radioactive waste.
Claims (6)
る緩衝材または埋め戻し材（これらを充填材と略称す
る）であって、陽イオン交換性の膨張型粘土鉱物と微細
なクラックを有する火山ガラスとを混合してなることを
特徴とする放射性廃棄物埋設用充填材。1. A cushioning material or backfilling material (which is abbreviated as a filling material) used when a radioactive waste drug is buried underground, which has a cation exchangeable expansive clay mineral and fine cracks. A filling material for burying radioactive waste characterized by being mixed with volcanic glass.
鉱物および微細なクラックを有する火山ガラスとを混合
してなることを特徴とする放射性廃棄物埋設用充填材。2. A filling material for burying radioactive waste, which is obtained by mixing excavated soil with cation-exchange expansive clay mineral and volcanic glass having fine cracks.
る請求項１または２の放射性廃棄物埋設用充填材。3. The filling material for burying radioactive waste according to claim 1 or 2, which contains fine powder of mineral substances together with volcanic glass.
ナイト、火山ガラスが溶結凝灰岩粉、鉱物質微粉末がフ
ライアッシュである請求項１、２または３の放射性廃棄
物埋設用充填材。4. The filling material for burying radioactive waste according to claim 1, 2 or 3, wherein the cation-exchange expandable clay mineral is bentonite, the volcanic glass is welded tuff powder, and the fine mineral powder is fly ash.
比が５０〜６００％である請求項１〜４の何れかに記載
する放射性廃棄物埋設用充填材。5. The filling material for burying radioactive waste according to claim 1, wherein the weight ratio of volcanic glass to bentonite is 50 to 600%.
ラスの混合材の重量比が２５〜４６％である請求項１〜
５の何れかに記載する放射性廃棄物埋設用充填材。6. The weight ratio of the mixed material of bentonite and volcanic glass to excavated soil is 25 to 46%.
The filling material for burying radioactive waste according to any one of 5 above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001345353A JP4096328B2 (en) | 2001-11-09 | 2001-11-09 | Filler for radioactive waste burial |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001345353A JP4096328B2 (en) | 2001-11-09 | 2001-11-09 | Filler for radioactive waste burial |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003149391A true JP2003149391A (en) | 2003-05-21 |
| JP4096328B2 JP4096328B2 (en) | 2008-06-04 |
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ID=19158698
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001345353A Expired - Fee Related JP4096328B2 (en) | 2001-11-09 | 2001-11-09 | Filler for radioactive waste burial |
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| Country | Link |
|---|---|
| JP (1) | JP4096328B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9446380B2 (en) | 2011-04-18 | 2016-09-20 | Gunma University | Water-blocking filler and filler for engineered multi-barriers using said water-blocking filler |
| CN108461170A (en) * | 2018-04-24 | 2018-08-28 | 海南大学 | A kind of novel Deep Geological Disposal of High-level Radioactive Wastes padded coaming and its construction method |
| CN110570964A (en) * | 2017-12-27 | 2019-12-13 | 兰州大学 | Backfill material for high-level waste disposal warehouse and preparation method thereof |
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|---|---|---|---|---|
| JPS63214699A (en) * | 1987-03-03 | 1988-09-07 | 三菱マテリアル株式会社 | Filler for burying radioactive waste |
| JPH03150500A (en) * | 1989-11-08 | 1991-06-26 | Ishikawajima Harima Heavy Ind Co Ltd | Formation disposal for radioactive waste |
| JPH07270597A (en) * | 1994-03-30 | 1995-10-20 | Mitsubishi Materials Corp | Buffer material or back-filling material for geological disposal of radioactive waste |
| JP2000073333A (en) * | 1998-08-28 | 2000-03-07 | Jdc Corp | Granular bentonite, manufacture of granular bentonite, bentonite mixed soil material, and water impervious construction method |
| JP2000212935A (en) * | 1999-01-25 | 2000-08-02 | Kumagai Gumi Co Ltd | Water barrier stratum |
| JP2001302307A (en) * | 2000-04-27 | 2001-10-31 | Taiheiyo Cement Corp | Cement additive and concrete composition produced by using the same |
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2001
- 2001-11-09 JP JP2001345353A patent/JP4096328B2/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63214699A (en) * | 1987-03-03 | 1988-09-07 | 三菱マテリアル株式会社 | Filler for burying radioactive waste |
| JPH03150500A (en) * | 1989-11-08 | 1991-06-26 | Ishikawajima Harima Heavy Ind Co Ltd | Formation disposal for radioactive waste |
| JPH07270597A (en) * | 1994-03-30 | 1995-10-20 | Mitsubishi Materials Corp | Buffer material or back-filling material for geological disposal of radioactive waste |
| JP2000073333A (en) * | 1998-08-28 | 2000-03-07 | Jdc Corp | Granular bentonite, manufacture of granular bentonite, bentonite mixed soil material, and water impervious construction method |
| JP2000212935A (en) * | 1999-01-25 | 2000-08-02 | Kumagai Gumi Co Ltd | Water barrier stratum |
| JP2001302307A (en) * | 2000-04-27 | 2001-10-31 | Taiheiyo Cement Corp | Cement additive and concrete composition produced by using the same |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9446380B2 (en) | 2011-04-18 | 2016-09-20 | Gunma University | Water-blocking filler and filler for engineered multi-barriers using said water-blocking filler |
| CN110570964A (en) * | 2017-12-27 | 2019-12-13 | 兰州大学 | Backfill material for high-level waste disposal warehouse and preparation method thereof |
| CN108461170A (en) * | 2018-04-24 | 2018-08-28 | 海南大学 | A kind of novel Deep Geological Disposal of High-level Radioactive Wastes padded coaming and its construction method |
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| Publication number | Publication date |
|---|---|
| JP4096328B2 (en) | 2008-06-04 |
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