# Reactor physics

Projective representation of the thermal neutron flux in a fuel element of a pressurized water reactor with the control rods retracted . Result of a physical reactor transport calculation.

The reactor physics, the reactor theory and experimental reactor physics comprises deals with the nuclear physics processes in a nuclear reactor . Reactor physics is shaped by the interaction of free neutrons with atomic nuclei in a limited space . The most important physical quantities in reactor physics are the number densities of atoms or atomic nuclei and free neutrons, the nuclear reaction rates , the cross sections of the nuclear reactions and the neutron flux . The subject area of reactor physics mainly comprises the "neutron physics of the reactor", for which the term "reactor neutrons" is rarely used.

Reactor physics is based on nuclear physics, developed out of it and was counted among it until the mid-1950s. Nuclear data (core data) will continue to be exchanged between nuclear physicists and reactor physicists. Other physical disciplines - not dealt with below - such as thermodynamics and fluid mechanics are also important for nuclear reactors, especially for power reactors .

## Physical view of a nuclear reactor

The splitting of atomic nuclei creates free neutrons in a relatively high number density and with high kinetic energy . They spread very quickly in space filled with matter, comparable to a gas . They collide with the atomic nuclei that are in the same space, thereby reducing their kinetic energy, triggering different nuclear reactions and thus changing the number densities of the nuclides in this space . They are finally captured again in fractions of a second by atomic nuclei, mainly fissile atomic nuclei. Therefore the radioactive decay of the neutron ( lifetime 880 s) can be neglected in the neutron balance. With the absorption of the neutron in an atomic nucleus, the “life path” of this neutron is ended; if the capturing nucleus is a fissile nuclide and the fission actually occurs, it releases a new generation of neutrons.

## Basics

The basic equation of reactor physics is Boltzmann's neutron transport equation, a real partial integro-differential equation to which the neutron angular flux obeys. It can only be solved numerically approximately.

The neutron angular flux that solves the equation can be interpreted in a classical mechanical way and is a function of real quantities.

The approximation of Boltzmann's neutron transport equation, which is important for practice, is the neutron diffusion equation . In the stationary case, the neutron transport equation is mathematically approximated by an elliptical partial differential equation whose solution function is the neutron flux .

Specialist disciplines in which short changes in the reactor parameters over time, particularly accidents, are investigated are reactor kinetics and reactor dynamics. In them, neutron physics is coupled with fluid dynamics and thermodynamics.

## On the history of the separation of nuclear physics and reactor physics

Free neutrons in high number density have only been available for research and application since the Chicago Pile nuclear reactor was commissioned in 1942. All research work on this and on nuclear reactors in general in the years thereafter initially fell within the competence of nuclear physics. The number of physicists who dealt exclusively with neutron physics and nuclear reactors increased significantly, and the methodology increasingly moved away from that of low-energy nuclear physics. For this reason, the reactor physicists separated from the nuclear physicists in the mid-1950s, which was manifested in their own specialist journals and specialist organizations.

The First International Conference on the Peaceful Uses of Atomic Energy in Geneva in 1955 can be seen as a milestone in this separation . At this conference, the nuclear powers USA, USSR, Great Britain and France gave for the first time an insight into their activities and plans regarding the civil use of nuclear energy and into research in reactor physics. Then national nuclear research centers were founded in many countries, in Germany for example the nuclear research center Karlsruhe , the nuclear research facility Jülich and the central institute for nuclear physics Rossendorf . They already contained departments that had reactor physics or reactor theory in their names.

The first two journals, especially for the fields of reactor physics, reactor technology and nuclear technology , were the journals Nuclear Science and Engineering and Атомная энергия (Atomnaja energija) , both founded in 1956. Both journals are intended to be "sources of information on basic and applied research in all scientific fields related to the peaceful uses of nuclear energy and applications of nuclear particles and radiation." Nuclear Science and Engineering is published by the American Nuclear Society . One of the 19 working groups of this society is called Reactor Physics.

In 1957, the semi-autonomous Nuclear Energy Agency (NEA) was founded within the Organization for Economic Cooperation and Development (OECD) to promote the safe, environmentally friendly and economic use of nuclear energy, with its headquarters in Paris. The organization operates various nuclear databases in its Nuclear Data Services and a computer program service for computer programs used for the peaceful uses of nuclear energy. A not inconsiderable part of the programs administered and distributed by the NEA's computer program service was developed by reactor physicists or is used by reactor physicists and reactor technicians. Both reactor physicists and nuclear physicists contribute to the nuclear databases.

In the same year 1957 the first textbook on reactor physics and technology appeared in German. As a result, the author could not fall back on a uniform and generally recognized German terminology. He was faced with the choice of either adopting the English technical terms or creating his own German terminology and decided on the latter. Reactor physics is already mentioned in this book as an equal branch of physics alongside nuclear physics .

## Important physical reactor parameters

The physical quantities of the reactor theory worked out up to 1948 were compiled by an employee of the Oak Ridge National Laboratory . Around the end of 1950 this first phase of “finding the size” was completed. The reactor physicists gave names to a few quantities that are inconsistent with the usual rules for naming quantities within physics. One of these is the quantity called neutron flux . After the nuclear reaction rate density, it is considered to be the most important variable in reactor physics. This quantity is neither a “ flux ” nor a “ flux density ” in the physical sense. Misunderstandings associated with the name of this quantity run through the entire history of the development of reactor physics and in some cases have not yet been resolved. This is similar for another physical reactor variable, called the macroscopic cross section , albeit with less obvious consequences than for the neutron flux.

In the following table, representative of hundreds of physical reactor variables, those variables are listed that have been among the most important in reactor physics from the time the "size determination" was completed until today. After the size symbol, the independent variables that are relevant for the corresponding size are listed in brackets . It stands for the place, for the neutron energy, for the solid angle and for the time. The unit symbol stands for “number of neutrons”, the unit symbol for “number of nuclear reactions” and the unit symbol for “number of atoms”. Note that the same letters are used with the size symbol for the neutron density and the one for the nuclear reaction rate density as for units, but those size symbols differ in the font style from these unit symbols . ${\ displaystyle {\ vec {x}}}$${\ displaystyle E}$${\ displaystyle \ Omega}$${\ displaystyle t}$${\ displaystyle \ mathrm {n}}$${\ displaystyle \ mathrm {r}}$${\ displaystyle \ mathrm {a}}$${\ displaystyle n}$ ${\ displaystyle r}$

symbol unit Surname Type
${\ displaystyle r ({\ vec {x}}, t)}$ ${\ displaystyle \ mathrm {\ frac {r} {cm ^ {3} \ s}}}$ Nuclear reaction rate density Scalar
${\ displaystyle \ Phi ({\ vec {x}}, E, t)}$ ${\ displaystyle \ mathrm {\ frac {n} {cm ^ {2} \ s}}}$ Neutron flux Scalar
${\ displaystyle \ varphi ({\ vec {x}}, E, t)}$ ${\ displaystyle \ mathrm {\ frac {n} {cm ^ {2} \ s \ eV}}}$ Neutron flux spectrum Scalar
${\ displaystyle \ psi ({\ vec {x}}, E, \ Omega, t)}$ ${\ displaystyle \ mathrm {\ frac {n} {cm ^ {2} \ s \ eV \ sr}}}$ Neutron angular flux Scalar
${\ displaystyle {\ vec {J}} ({\ vec {x}}, E, t)}$ ${\ displaystyle \ mathrm {\ frac {n} {cm ^ {2} \ s}}}$ Neutron flux density vector
${\ displaystyle n ({\ vec {x}}, t)}$ ${\ displaystyle \ mathrm {\ frac {n} {cm ^ {3}}}}$ Neutron number density ("neutron density") Scalar
${\ displaystyle N ({\ vec {x}}, t)}$ ${\ displaystyle \ mathrm {\ frac {a} {cm ^ {3}}}}$ Atomic number density ("atomic density") Scalar
${\ displaystyle \ sigma (E)}$ ${\ displaystyle \ mathrm {cm ^ {2}}}$ Cross section Scalar
${\ displaystyle \ Sigma ({\ vec {x}}, t)}$ ${\ displaystyle \ mathrm {\ frac {1} {cm}}}$ Macroscopic cross section Scalar
${\ displaystyle B ({\ vec {x}}, t)}$ ${\ displaystyle \ mathrm {\ frac {kW \ d} {g}}}$ Specific burn-up Scalar
${\ displaystyle \ Phi _ {t} ({\ vec {x}}, E)}$ ${\ displaystyle \ mathrm {\ frac {n} {cm ^ {2}}}}$ Neutron fluence Scalar
${\ displaystyle k _ {\ mathrm {eff}}}$ ${\ displaystyle 1}$ Effective neutron multiplication factor Scalar
${\ displaystyle \ rho}$ ${\ displaystyle 1}$ Reactivity Scalar

The unit symbol stands for the solid angle unit steradian , the power unit watt and the time unit day . In the last column of the table the type of variable (scalar or vector) of the respective size is indicated. With the exception of the neutron flux density , all the quantities listed here are of the scalar type , such as a mass density, for example. ${\ displaystyle \ mathrm {sr}}$ ${\ displaystyle \ mathrm {W}}$${\ displaystyle \ mathrm {d}}$

## PHYSOR

Physics of Reactors (PHYSOR) conferences , organized by the American Nuclear Society together with other international forums, take place every two years. They bring reactor physicists together to share global expertise in reactor physics, nuclear reactor research and analysis, and related fields. The conference topics of PHYSOR 2018 were similar to those listed in the following section as sub-areas of reactor physics .

## Sub-areas of reactor physics

There is no generally binding subdivision of reactor physics, as becomes clear when comparing the tables of contents of the standard textbooks listed below . The differences can be understood if one compares the subdivision made in the PHYSOR conferences , for example, with the chapter headings of the Stacey monograph, which can be done with the excerpt from Google Books .

Following the PHYSOR conferences , reactor physics can be subdivided into the following sub-areas:

### Reactor analysis

The reactor analysis is dedicated to basic tasks of reactor physics. This sub-area defines the physical quantities that are relevant for the entire reactor physics. Based on this, reactor theorists developed and developed the physical and numerical-mathematical apparatus with which the distribution of neutrons within a spatial area can be described and calculated. The spatial area can be a partial area of ​​the nuclear reactor (“cell calculation”) or it can include the reactor as a whole and its immediate surroundings (“global reactor calculation”).

The central task is to determine the distribution of neutrons in this area of ​​space according to location, energy and direction of neutron flight, as well as depending on the selected point in time. In particular, reactor analysis includes the development of numerical solution methods for the basic equations of reactor physics. The approximation methods used differ significantly from reactor type to reactor type and are constantly being further developed.

It is "easier to derive the neutron transport equation (requires the concept of neutron conservation plus a little vector calculation) than to understand the neutron diffusion equation, which is used in most developments in reactor analysis." In practical implementation (program scope, computing times) it is exactly the opposite .

### Experimental reactor physics

Since the beginning of nuclear energy, numerous experiments on nuclear energy and nuclear technology have been carried out worldwide in various research laboratories, mainly on research reactors . A meeting report by the Leibniz Society gives an overview of experiments at the research reactors Rossendorf Research Reactor and Rossendorf Ring Zone Reactor . Even zero-power reactors ( "critical facilities"), such as SNEAK were and are critical of certain of the neutron-physical development of reactor types; they enable the measurement of the spatial neutron flux and power distribution in a planned reactor core, as well as of control rod - reactivity values , conversion rates , neutron spectra and different reactivity , especially coolant loss coefficient .

In 1999 the International Reactor Physics Experiment Evaluation (IRPhE) project was initiated as a pilot project of the NEA. Experimental data on reactor physics have been preserved since 2003, including measurement methods and data for applications in nuclear energy, as well as the knowledge and skills contained therein. The most important printed publication is the annual International Handbook of Evaluated Reactor Physics Benchmark Experiments.

### Deterministic transport theory

The deterministic transport theory , which includes the neutron diffusion theory, divides the independent variables of the transport equation , the space area, the energy and, if necessary, the neutron flight direction into discrete parts ( discretization ) and solves the resulting systems of difference equations numerically. The focus is primarily on the critical, i.e. stationary, reactor . However, changes over time over longer periods of time also belong in this sub-area, whereby the quantity burn-up is used instead of the independent variable time . This includes calculations of the energy spectrum of neutrons and generation of multi-group cross-sections as well as lattice and cell problems.

### Monte Carlo methods

What is now called the Monte Carlo method or Monte Carlo simulation was invented by a mathematician in the context of neutron transport. With a Monte Carlo method, now widely used in other areas, life paths of particles are simulated. The particle is followed from its appearance in a given space ( birth in or entry into the space) through all core processes within the space up to its disappearance from this space ( death or exit from the space). The geometry and material distribution of the spatial area and the nuclear data belong to the input data. Using the probability distribution of each event, each phase of the particle's life can be statistically tracked and recorded using a pseudo-random number . A well-known computer program based on the Monte Carlo method is MCNP .

### Fuel cycle

In reactor physics (theoretical aspects) and nuclear technology (practice), the fuel cycle denotes all work steps and processes that serve to supply and dispose of radioactive substances. The respective neutron physical investigations, such as criticality calculations for the safe interim storage of spent fuel elements, belong to the field of work of reactor physics and reactor technology.

### Transient and safety analysis

In addition to the investigation of stationary and quasi-stationary states of the nuclear reactor, reactor physics and technology also include the investigation of states in which the effective neutron multiplication factor is not equal to 1. Neutron flux and reactor power are time-dependent. A changed reactor power changes the effective neutron multiplication factor via the temperature coefficient. Time-dependent states of the reactor, known as transients , play a major role in reactor accidents. They are divided into several categories: for example, the design basis accident of a nuclear power plant, for the safety systems designed are and will be dominated by these needs, loss of coolant accidents , caused by the leakage of coolant from the cooling circuit, or Reaktivitätsstörfälle , triggered by accidental "supply" of Reactivity leading to a performance excursion. For the safety of nuclear power plants , especially with new reactor concepts, the physical examinations of the reactor are decisive.

### Nuclear data (core data)

The reactor physicist needs, as input data for his computer programs, nuclear data for all nuclides that are used in a nuclear reactor when it is commissioned or that are formed in the course of operation through nuclear reactions. These nuclear data are mainly obtained from measurements. In almost no case, theoretical nuclear physics can calculate these quantities with an accuracy that is required today for calculations in reactor physics.

Cross- sections for 6 nuclear reactions of neutron and atomic nucleus 235 U and their sum as a function of the kinetic energy of the neutrons. In the legend, z is sometimes used instead of the usual symbol n for neutron (data source: JEFF, graphic representation: core data viewer JANIS 4)

Nuclear data is therefore of fundamental importance, especially for reactor physicists and technicians, but it can also be of fundamental importance for biologists and doctors, for example. Nuclear data include the physical quantities of the radioactive decay properties, fission yields and interaction data ( cross sections , resonance parameters , energy and angular distributions ...) for different projectiles (neutrons, protons, etc.), and this over a wide energy range of these projectiles.

The nuclear data are stored in databases and are disseminated from there. Special formats exist for experimental data (EXFOR), estimated data (ENDF, JEFF, ENSDF), or processed data (PENDF, GENDF). However, the nuclear data are so varied and their quantity so large that a user will usually seek the help of an expert who specializes in nuclear data, usually a specialized reactor physicist. With the Java-based Nuclear Information Software (JANIS) visualization program, for example, it is possible for anyone to access numerical values ​​from all of these databases and graphic representations without prior knowledge of the storage formats after a finite familiarization period.

The atomic masses fall into a second category of data, which strictly speaking does not belong to the core data . They are required to calculate the number densities of all nuclides present in a spatial area. They represent the core masses . Estimated atomic masses are published at longer intervals in an atomic mass evaluation .

### Reactor concepts

The research area of reactor concepts for power operation is by no means closed in terms of reactor physics. The classic reactor types and a number of special types have been relatively well researched . Six fourth generation reactor types have been on the test bench since 2000 :

• Fast gas-cooled reactor
• High temperature reactor
• Light water reactor with supercritical water as moderator, coolant and heat exchanger
• Fast sodium-cooled reactor
• Molten salt reactor

### Research reactors

Research reactors are used for physical, nuclear and material engineering investigations and / or produce radionuclides for medicine and technology. The neutron radiation from the reactor is used and not the thermal energy. A well-known German research reactor is accordingly called a research neutron source. Research reactors are also used for training purposes. The operation of a research reactor requires detailed accompanying calculations for the physics of the reactor, especially if it is used in a variety of ways.

### Environmental impact of nuclear activities

For this area, more than 170 computer programs, which were developed by reactor physicists, are listed in the Environmental and Earth Sciences category of the NEA-Computer Program Services in 2018.

## Reactor physics, reactor technology, nuclear technology

Reactor physics and reactor technology relate to one another like physics and technology in general. Planning, design , construction, operation and decommissioning of a nuclear reactor are largely the responsibility of reactor technology. The core technology includes the reactor technology, but also includes the technique of nuclear medicine and radiotherapy and various applications of radioactivity .

Also, some textbooks that neutron physics or neutron physics lead in the title, the reactor physics and less physics devote most of the neutron itself (neutron structure) or about the physics of neutron induced nuclear reactions in AGB stars .

## Computer programs for reactor physics

In addition to the already mentioned Monte Carlo program for the simulation of nuclear processes MCNP, there is the deterministic neutron diffusion program PDQ. It is a two-dimensional reactor design program, written in the Fortran programming language , which established itself as the standard programming language in reactor physics, and was published in 1957. PDQ calculates a discrete numerical approximation of the neutron flux from the time-independent neutron diffusion equations for a few energy groups for a heterogeneous reactor in a two-dimensional rectangular area. The independent position variables are either in Cartesian coordinates or in cylindrical coordinates . ${\ displaystyle (x, y)}$${\ displaystyle (r, z)}$

The PDQ program was the model for dozens of computer programs with the same objective worldwide. It was further developed over decades and (like all fine lattice neutron diffusion programs ) only lost its dominant position in reactor physics after the development of so-called nodal diffusion programs . The development work on this program is still considered a milestone in computer-aided numerical mathematics .

In the NEA's Computer Program Services library , predominantly, but not exclusively, reactor physics programs are collected, tested and passed on free of charge to institutes and universities of the member states of the OECD. In the reactor physics category Static Design Studies alone, 60 programs in the Fortran programming language are listed.

## Eminent reactor physicists

Eugene Wigner (left) and Alvin Weinberg at the Oak Ridge National Laboratory

Since 1990, the Eugene P. Wigner Reactor Physicist Award has been presented annually by the American Nuclear Society for outstanding achievements to reactor physicists . It is named in honor of Eugene Paul Wigner , who was also the first prize winner. The second laureate, reactor physicist Alvin M. Weinberg , became known among reactor physicists around the world for the textbook The physical theory of neutron chain reactors, which he wrote together with his teacher Wigner. From 1955 to 1973 he was director of the Oak Ridge National Laboratory (ORNL).

In 1973 Weinberg was dismissed from the Nixon administration as head of the ORNL because he had advocated a high level of nuclear safety and the molten salt reactor (MSR), and the development of which Weinberg had been promoting since 1955, was stopped. There was a brief revival of MSR research at the ORNL as part of the Carter Administration's nonproliferation program - a final publication that is still considered by many to be the reference design for commercial molten salt reactors .

Rudolf Schulten explains the fuel element of a pebble bed reactor

In Germany, Karl Wirtz and Rudolf Schulten should be mentioned. Wirtz had already worked for Heisenberg in the German uranium project , designed and managed the construction of the first successful German research reactor FR 2 , was a co-founder of the breeder reactor development in Europe and professor at the Technical University of Karlsruhe . Schulten also taught reactor physics at this university and wrote a textbook on reactor physics in 1960 together with Wernfried Güth . Schulten took up the idea of ​​the pebble bed reactor from Farrington Daniels .

## Institutes and universities dealing with reactor physics

In Germany, reactor physics and related areas are worked on and taught in Aachen, Dresden and Karlsruhe, among others.

In Switzerland there are courses of study that include the subject of reactor physics at the technical colleges in Zurich and Lausanne. In Austria, the Vienna University of Technology offers a corresponding degree program.

In France, reactor physics and engineering is taught in the Nuclear Reactor Physics and Engineering department at the University of Paris-Saclay . In France, the Nuclear Reactor Physics Group at the University of Grenoble Alpes should also be mentioned.

In the Netherlands, the Reactor Physics and Nuclear Materials department at Delft University of Technology is the only academic group that trains and conducts research in the field of reactor physics.

## literature

### Standard textbooks

There are well over a hundred textbooks on the subjects of reactor physics, reactor theory and reactor analysis . The standard textbooks listed here were selected after a survey of reactor physicists.

• Samuel Glasstone , Milton C. Edlund: The elements of nuclear reactor theory . MacMillan, London 1952 (VII, 416 pp., Online ). This monograph occupies a prominent position because like no other it shaped the then young generation of reactor physicists in West and East and the later textbook writers. It is fully online in the 6th print from February 1957. Full text search is possible. Translation: Samuel Glasstone, Milton C. Edlund: Nuclear Reactor Theory. An introduction. Springer, Vienna 1961, 340 pp.
• Alvin M. Weinberg , Eugene Paul Wigner : The physical theory of neutron chain reactors . Univ. of Chicago Press, Chicago 1958, ISBN 0-226-88517-8 (XII, 800 pages).
• John R. Lamarsh: Introduction to nuclear reactor theory . Addison-Wesley, Reading, Mass. 1966 (XI, 585 pp.).
• George I. Bell, Samuel Glasstone: Nuclear reactor theory . Van Nostrand Reinhold, New York 1970 (XVIII, 619 pp.).
• James J. Duderstadt, Louis J. Hamilton: Nuclear reactor analysis . Wiley, New York 1976, ISBN 978-0-471-22363-4 (xvii, 650 pages).
• Rudi JJ Stammler, Máximo J. Abbate: Methods of steady-state reactor physics in nuclear design . Acad. Press, London 1983, ISBN 0-12-663320-7 (XVI, 506 pages).
• Аполлон Николаевич Климов (Apollon Nikolajewitsch Klimow): Ядерная физика и ядерные реакторы . Атомиздат, Москва 1971 (384 p.).
• Paul Reuss: Neutron physics . EDP ​​Sciences, Les Ulis, France 2008, ISBN 978-2-7598-0041-4 (xxvi, 669 pages).
• Elmer E. Lewis: Fundamentals of nuclear reactor physics . Academic Press, Amsterdam, Heidelberg 2008, ISBN 978-0-12-370631-7 (XV, 293 pages).
• Weston M. Stacey: Nuclear Reactor Physics . Wiley, 2018, ISBN 978-3-527-81230-1 ( limited preview in Google Book Search).

### Textbooks in German

• Ferdinand Cap : Physics and technology of nuclear reactors . Springer, Vienna 1957 (XXIX, 487 pages, limited preview in the Google book search [accessed on August 21, 2018]). This book is the result of lectures that the author has given at the University of Innsbruck since the 1950/51 academic year.
• Karl Wirtz , Karl H. Beckurts : Elementary Neutron Physics . Springer, Berlin 1958 (VIII, 243 p., Limited preview in the Google book search [accessed on August 21, 2018]).
• Aleksey D. Galanin: Theory of thermal nuclear reactors . Teubner, Leipzig 1959 (XII, 382 pages). The original monograph was published in Russian in 1957 and in 1960 by Pergamon Press in English translation under the title Thermal reactor theory.
• Rudolf Schulten, Wernfried Güth: reactor physics . Bibliogr. Institute, Mannheim 1960 (171 pages).
• John J. Syrett: Reactor Theory . Vieweg, Braunschweig 1960 (VIII, 107 pp.).
• Josef Fassbender: Introduction to reactor physics . Thiemig, Munich 1967 (VIII, 146 pp.).
• Dieter Emendörfer, Karl-Heinz Höcker : Theory of nuclear reactors . Bibliographisches Institut, Mannheim, Vienna, Zurich 1970 (380 pages).

### Textbooks on reactor technology

• Werner Oldekop: Introduction to nuclear reactor and nuclear power plant technology. Part I: Fundamentals of nuclear physics, reactor physics, reactor dynamics . Thiemig, Munich 1975, ISBN 3-521-06093-4 (272 pages).
• Dieter Smidt: Reactor technology . 2nd Edition. Braun, Karlsruhe 1976, ISBN 3-7650-2019-2 (XVI, 325 pages).
• Albert Ziegler: Textbook of reactor technology . Springer, Berlin, Heidelberg 1983, ISBN 3-540-12198-6 (XI, 242 pages).
• Albert Ziegler, Hans-Josef Allelein (Hrsg.): Reactor technology: physical-technical basics . 2nd, revised edition 2013. Springer Vieweg, Berlin 2013, ISBN 978-3-642-33846-5 (634 pages, limited preview in the Google book search [accessed on August 21, 2018]).

## Individual evidence

1. ^ Boris Davison, John B. Sykes: Neutron transport theory . Clarendon Pr, Oxford 1957, p. 15 ff . (XX, 450).
2. Kenneth M. Case, Frederic de Hoffman, Georg Placzek: Introduction to the theory of neutron diffusion. Volume I . Los Alamos Scientific Laboratory, Los Alamos, New Mexico 1953.
3. Eugene L. Wachspress: Iterative solution of elliptic systems and applications to the neutron diffusion equations of reactor physics . Prentice-Hall, Englewood Cliffs, NJ 1966 (XIV, 299 pp.).
4. ^ David L. Hetrick: Dynamics of nuclear reactors . Univ. of Chicago, Chicago 1971, ISBN 0-226-33166-0 (542 pages).
5. ^ Karl O. Ott, Robert J. Neuhold: Introductory nuclear reactor dynamics . American Nuclear Soc, La Grange Park, Ill. 1985, ISBN 0-89448-029-4 (XII, 362 pp.).
6. ^ Nuclear Science and Engineering
7. Атомная энергия
8. ^ Nuclear Data Services
9. Computer Program Service
10. ^ Ferdinand Cap: Physics and technology of atomic reactors . Springer, Vienna 1957 (XXIX, 487 pages, limited preview in the Google book search [accessed on August 21, 2018]).
11. ^ Nicholas M. Smith, JR .: Nuclear Engineering Glossary: ​​Reactor Theory . Oak Ridge, Tennessee - ORNL 84 1948 (64 pages, still reproduced in the Ormig process).
12. Physics of Reactors (PHYSOR)
13. PHYSOR 2018
14. ^ Weston M. Stacey: Nuclear Reactor Physics . Wiley, 2018, ISBN 978-3-527-81230-1 ( limited preview in Google Book Search [accessed August 25, 2018]).
15. James J. Duderstadt, Louis J. Hamilton: Nuclear reactor analysis . Wiley, New York 1976, ISBN 978-0-471-22363-4 , pp. 106 (xvii, 650 pp.).
16. ^ Allan F. Henry: Nuclear reactor analysis . MIT Press, Cambridge, Mass. 1975, ISBN 0-262-08081-8 (XII, 547 pp.).
17. James J. Duderstadt, Louis J. Hamilton: Ibid., P. 104.
18. Peter Liewers: Research on reactor physics in the GDR . In: Meeting reports of the Leibniz Society . tape 89 . trafo-Verlag, Berlin 2007, ISBN 978-3-89626-692-7 , p. 39–54 ( online [PDF; accessed August 27, 2018]).
19. W. Marth: The fast breeder SNR 300 in the ups and downs of its history. (PDF; 5.5 MB), report KFK 4666 of the Karlsruhe Nuclear Research Center, May 1992.
20. International Reactor Physics Experiment Evaluation (IRPhE)
21. International Handbook of Evaluated Reactor Physics Benchmark Experiments.
22. Edmond Darrell Cash Well, Cornelius Joseph Everett: A practical manual on the Monte Carlo method for random walk problems . University of California, Los Alamos (New Mexico) 1957 (228 pp., Online [PDF; accessed June 19, 2018]).
23. EXFOR
24. M. Herman, A. Trkov (Eds.): ENDF-6 Formats Manual. Data Formats and Procedures for the Evaluated Nuclear Data File / B-VI and ENDF / B-VII . Brookhaven National Laboratory; Distributed by the Office of Scientific and Technical Information, US Dept. of Energy, Upton, NY, Oak Ridge, Tenn. 2009 (XIII, 372 pp., Online [PDF; accessed on August 28, 2018]).
25. Java-based Nuclear Information Software (JANIS)
26. ^ Environmental and Earth Sciences
27. ^ Karl Wirtz, Karl H. Beckurts: Elementare Neutronenphysik . Springer, Berlin 1958 (VIII, 243 pages).
28. ^ Paul Reuss: Neutron physics . EDP ​​Sciences, Les Ulis, France 2008, ISBN 978-2-7598-0041-4 (xxvi, 669 pp, limited preview in Google Book Search [accessed August 25, 2018]).
29. Gerald G. Bilodeau, WR Cadwell, JP Dorsey, JG Fairey, Richard S. Varga: PDQ - An IBM-704 Code to Solve the Two-Dimensional Few-Group Neutron-Diffusion Equations, Bettis Atomic Power Laboratory Report WAPD-TM- 70 . Pittsburgh, Pennsylvania 1957 ( online [accessed August 21, 2018]).
30. ^ Computer Program Services
31. ^ Static Design Studies
32. JR Engel et al .: Conceptual design characteristics of a denatured molten-salt reactor with once-through fueling . Oak Ridge National Laboratory Report ORNL / TM-7207, Oak Ridge, Tenn. 1980 (156 pp., Online [PDF; accessed on August 21, 2018]).
33. Ulrich Kirchner: The high temperature reactor. Conflicts, interests, decisions . Campus-Verlag, Frankfurt / Main 1991, ISBN 3-593-34538-2 (240 pages).
34. ^ Farrington Daniels: Neutronic reactor system. Patent US2809931, filed in 1945, granted in 1957.
35. ^
36. ^
37. ^
38. ^
39. ^
40. ^
41. ^
42. ^