Science & Industry: Nuclear Safety:


The Neglected Th-NPPs

Insight into Thorium (Th) Chemistry    


by Dr.rer.nat., Randolph Riemschneider

Prof. UFSM Brazil,  em.Prof. FU Berlin

Exec.Vice Dir. of The BWW Society

and The Inst. for Positive Global Solutions



Thorium liquid salt NPPs are immune against MCA - as opposed to uranium/plutonium NPPs. In case of emergency, for example a blackout, they can be switched off manually at any time. Unfortunately the West gave preference to the U/Pu-based NPPs over the safer Th-NPPs.


In cooperation with HOECHST a) reconversion of used nuclear fuel of 232Th, U: thorex process; study of the Th(NO3)4-chemistry (1), b) water-soluble Th-compds from HThCl3 + unsaturated compds. like CH2=CH-CN, (CH2=CH-COOH) for toxicological expts., analogue to chemistry of Ge, but other catalysts (2)[i].



The author's interest in the chemistry of thorium and germanium was aroused in 1943 when the head engineer Keller of RUHRÖL, Bottrop, asked him for literature on the analysis of these elements (3). The author's friend, the Swiss engineer O. Matter, was the expert for experiments with explosives like Th(NO3)4. In 1949, the author worked with Drs. H.J. Hein and D. Kirstein on the cultivation of baker's yeast in a solution containing Th acetate (2). Dr. H. Pehlmann was in charge of the examination of materials containing Th by means of ICI analysis (4).


Let us now turn to the Th liquid salt NPPs: When the nuclear bombs were dropped on Hiroshima (U bomb) and Nagasaki (Pu bomb) in August 1945, we entered the nuclear age, aiming for "peaceful nuclear energy" at the same time. In 1947, the author (5) warned against a so-called peaceful exploitation of the MCA-susceptible U nuclear energy in essays such as "Earth itself is the greatest power plant on earth" (advocating geothermal energy instead) - unfortunately without any success as has been shown by the accidents in Chernobyl (1986) and Fukushima (2011) and will hopefully never be shown again, let alone EMP, both naturally or in the form of a bomb (6)[ii]. See the author's book "75 Years of Chemistry – Re-Reading", Part V-A, pp. 881/2). This is where you will also find details on the topic of "Thorium liquid salt reactors" namely in Part V-B, pp. 1049 et seqq. which are repeated here:


The team around Alvin Weinberg (Manhattan Project)  first developed a nuclear project in the United States which did not use uranium (U), but thorium (Th) as a fissionable material when bombarded with neutrons, Th232 yielded fissionable U233 . By neutron irradiation, U233 is bred from Th232, this disintegrates via protactinium Pa233 to obtain U233.

thorium gleichung



cf. Part I, p 668


As Weinberg's further development of Th-based nuclear energy showed, it is possible to build reactors which, opposed to uranium-based ones, work in a liquid medium without pressure: Th is dissolved in salts such as metal halides and irradiated with neutrons. The resulting heat is commonly used to generate electricity: temperatures up to 800°C. Overheating by expansion of the salt solution containing Th results in automatic shut-down (the effect of the neutrons being inhibited by greater spacing). It is possible to stop the Th fission process at any time by opening the lower valve of the reactor by hand and allowing the contents to drain (the mass will solidify), whereas starting and shutting down uranium (and plutonium) reactors is a problem, since an immediate shutdown is not possible.


These facts show that a thorium liquid salt reactor [iii] is very safe: There can be no MCA (as in Chernobyl), there is no water nearby which could be cleaved and result in an explosion of the hydrogen formed (Fukushima). Such reactors would be operated without pressure, there is less waste than with uranium-based nuclear technology, namely 80% less, and the time of radiation emission of the waste is much shorter.”


American and European politicians [but Germany 2011: see below] had decided against Th technology at the future. Not so PR China: Thorium minerals can be found in many countries so that Th technology could become a possibility for everyone. Under Tchu En-Lai in the 1970s, PR China started to develop and to use Th liquid salt reactors when coal became scarce in Shanghai [see ADDENDUM in Part A, p 1035].


PR China (and South Africa) use also another kind of U-based NPP, namely of PBMR-type, Pebble Bed Modular Reactor, working with U fuel material encapsulated in silicon carbide spheres and these, in turn, embedded in graphite (but not used in Germany where this NPP type was first developed).


The above mentioned Manhattan Project devised by the Americans in WWII made the development of uranium-based nuclear bombs and NPPs possible: The instability and danger of U-NPPs was accepted, the focus was not on problems with safety. Later on, the public was deceived by military and politicians who spoke "of the peaceful use of nuclear energy", but actually focused on recovering fissionable material. The reason is that the U-based NPPs supplied not only nuclear energy but, at the same time, a new fissionable material (Plutonium) suitable for use as a weapon. The result was a powerful nuclear industry in many countries which was dominated by the military and politicians: In the United States, two Commissions controlled nuclear research, namely Commission a the military and Commission b the civil aspects. General H. Rikowa was head of a, but was a member of b at the same time - which made it possible that he was able to answer "a letter sent from a as a member of b and vice versa", i.e. there was no strict separation of a and b (source of this information: German TV N 24).


The German Chancellor Merkel turned around: Short time before 2011 she extended the lifespan of existing nuclear power plants, and after the Fukushima disaster 2011 some U-NPPs were switched off with immediate effect and complete withdrawal from nuclear energy announced without any consultation with the German Parliament, with the  industry concerned and with the other 27 European countries, i.e. without thinking of the consequences[iv] : legal dealings with the industry and follow-up cost. All other European  countries continue their U-nuclear reactors. In the Saar area, it is possible to watch a French nuclear power plant operating from some of the windows.


As far as the starting material is concerned, France could easily switch to thorium since the country has a stock of 50 tons of fissionable Th (2015) recovered in the course of separating Th and rare earth. However, the French nuclear industry wants to stay with the present technology as long as possible and prefers to extend the lifespan of existing reactors rather than starting from scratch with Th.


The demanded necessary change from the U- to Th-NPPs entails immense costs: The U.N. Security Council has to be called in.


In connection with the 40 year cooperation with HOECHST mentioned at the outset, meetings took place once a year at the factory in Frankfurt-Hoechst. The participants were Dr. F. Scherer, Dr. Frensch, Dr. Behr (patent attorney), the author and sometimes Director Winnacker. The latter was in charge of the topics of Th and D chemistry: recovery of Th by decomposition of ThJ4 on glow wires, breaking down monazite sand, treatment of nuclear fuel residues, perdeuterated hydrocarbons (7). - The author's obligation of confidentiality expired with the liquidation of HOECHST in 1990: refs (923a-g)  in (1).





(1)  R.Riemschneider, "75 Years Chemistry – Re-Reading" PROJ. XXXII: Thorex process; R.Riemschneider, H.-J.Hein, E.Hausmann, E.Schölzel, O.Matter (5) Preparation of Th-salts: ThCl4, ThF4, Th(OOC-COO)2, Th(NO3)4, Th-lactat, Th-acetat: (923a) 1947-1958; cf..also Part V-B, p 1048.      

(2)   R.Riemschneider, H.-J.Hein. D.Kirstein, Experiments to open an organic Th-chemistry –  in analogy to the Ge-chemistry; see Z.Naturforschg. 11b, 115/6 (1956) , Part V-B, p 1048:  (923d). Th expts remain unpublished. – Ge-chemistry in Part IV, p 479/80, 498, 500.  

(3)   R.Riemschneider, "Re-Reading", PROJ.XVI, Ing.Keller in Part IV, p 493/4

(4)   R.Riemschneider, "Re-Reading", PROJ.XVI, ICP, in Part IV, p 512ff. - Th-expts. H.Pehlmann    

(5)   R.Riemschneider, "Das größte Kraftwerk der Erde ist die Erde selbst", Publishing house  "Volk und Wissen" 1947/8, 30 pages + 14 sketches - auch "Thüringer Volk",Tagesztg.1947, Part V-A, p 878 (English translation: p 1032/3).

(6)   R.Riemschneider, "Re-Reading", EMP (natural or bomb), Part V-A, p 881/3: also in the author's letter to D.Trump of Jan.24, 2017 ; see also endnote ii of this essay

 (7) R.Riemschneider, P.Blümel, H.Beck, Z.Naturforschg. 18b, 452/4 (1963); cf.

      Part II, p 96/7: (176, 180b): Tab 1-7 in Part II (complete version)

 (8)  R.Riemschneider, Commentaries on the Refugee Crisis in Germany I and II, in Part V-B, p 1051,1053ff. See also,htm (2x 2016)


Appendix to bibliography:


First publications to the topic "Addukte aus HGeCl3 und ungesätigte Verbindungen in "Mitteilungen des Physiologisch-chemischen Instituts Berlin, Dez.1949", copied in Part IV, p 498: Plate 3a, publication in Part IV, p 500: Plate 4, also Z.Naturforschg.11b, 115- 116 (1956); Plate 5 in Part IV, p 501; cf. also refs (917a-c) in Part IV, p 483/4. Analoge Si-Chemie in Part IV, p 502/3: Plate 6: DRP 1 062 243.





NPP Accidents/Disasters  -  MCA-Immune NPPs

by Dr.rer.nat., Randolph Riemschneider

Prof. UFSM Brazil,  em.Prof. FU Berlin

Exec.Vice Dir. of The BWW Society and The Inst.for Positive Global Solutions


In Table 1 are listed the known accidents/disasters of U/Pu-based NPPs, in Table 2 are listed the MCA-immune NPPs, based on U/Th.


Table 1: Publicised U/Pu nuclear reactor accidents and disasters (1957 - 2011)


             1      1957                         USSR                          Majak, Tscherjabinsk Ural              

             2      1957, 1980               Great Britain               Windscale accidents

             3      1969                         Switzerland                 Lucenz accident

             4      1979                         USA                            Harrisburg accident    

             5      1986                         Great Britain               Sellafield accident  

             6      1986                         USSR                          Chernobyl

             7      1989                         Estonia                        Vandellos accident
             8      1992                         Russia                          St. Petersburg accident

             9      1991,'97, '99, 2004   Japan                           Japanese accidents

           10      2011                         Japan                          Fukushima



Table 2: MCA-immune  NPPs, based on U/Th


            1         Uran-NPPs of PBMR-type (pebble bed modular reactors)

            2         Thorium liquidsalt reactors

ad 1      

Quotation of H J Werhahn, expert of energy problems: "The pebble bed type technology is inherently far safer than any conventional reactor technology, even if  the latter is further improved by retrofitting. Right from the beginning, the pebble bed type technology was intended for areas of concentrated habitation. This was possible only because this technology is inherently safe. An U-based pebble bed type reactor cannot blow for natural reasons"


In the PMB technology, reinforced grains having the size of a grain of sand are used  instead of fuel rods. These are nuclear fuels of the size of a needle point  surrounded by a sheath of silicon carbide having the hardness of a diamond. Then they are encased  in a palm-sized graphite ball. All this warrants practically unlimited stability. The nuclear fuel is continuously fed into and withdrawn from the reactor in the form of balls without the reactor having to be switched on. This also solves the tiresome problem of ultimate disposal – not to mention that we would  be safe against terroristic attacks.


ad 2      

Switching from uranium to thorium avoids the evolvement of the dangerous and highly toxic plutonium. Thorium is found in monazite deposits which will last for many years: The author wrote in Part I, p 668: "In the thorium high-temperature  reactor such as the THTR-300, thorium is used to prepare the uranium isotope 233U by neutron irradiation: 233Th is bred from 232Th; this disintegrates via protactinium   233Pa to obtain uranium 233U; cf. equation"

thorium gleichung

In the meantime, a technology was being developed to carry out this reaction in the so-called Th-liquidsalt-NPPs. The obtained 233U is fissionable and is consumed by the reactors. More details regarding Th-liquidsalt.NPPs in the essay "Neglected Thorium-NPPs"  in                             

[i]    See last paragraph of  this text

[ii]   It is hoped that U.S. President Donald Trump will include the "safety of NPPs for the American people" in his propagated "change of politics" and his "America First", i.e. that he will have all of the U/Pu-NPPs which are at risk through EMP (both through natural causes or external impact) replaced by Th liquid salt NPPs while in office. 

[iii]    Further details in Project XXXI

[iv]    As was when she invited a million refugees into the country: "We'll get this done" etc;       cf the author's essays (8).




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