1) Neutron radiation consists of free neutrons released during nuclear fission or fusion and can induce radioactivity in materials through neutron capture. 2) Neutron radiation poses health risks both from its ionizing effects and its ability to induce radioactivity, making materials and tissues radioactive. 3) An anti-radiation vaccine containing inactivated radiation toxins was found to increase survival time in rabbits exposed to lethal doses of neutron radiation from 2 hours in untreated rabbits to up to 11 days in vaccinated rabbits.

1. Neutron Radiation: Radiation
Protection.
Dmitri Popov. PhD, Radiobiology.
MD (Russia)
Advanced Medical Technology and Systems Inc. Canada.
Slava Maliev, PhD, Radiobiology,
Academy of Science, Russia.

2. Neutron radiation: Radiation Protection.
• Neutron radiation is a kind of ionizing radiation which consists of free
neutrons. A result of nuclear fission or nuclear fusion, it consists of
the release of free neutrons from atoms, and these free
neutrons react with nuclei of other atoms to form new isotopes,
which, in turn, may produce secondary, induced radiation.
• https://en.wikipedia.org/wiki/Neutron_radiation
• http://www.slideshare.net/dlpopov/induced-radioactivity
• http://www.intechopen.com/books/current-topics-in-ionizing-
radiation-research/radiation-toxins-molecular-mechanisms-of-
toxicity-and-radiomimetic-properties-

3. Neutron radiation: Radiation Protection.
• Cosmogenic neutrons, neutrons produced from cosmic radiation in
the Earth's atmosphere or surface, and those produced in particle
accelerators can be significantly higher energy than those
encountered in reactors.
• Most of them activate a nucleus before reaching the ground; a few
react with nuclei in the air.
• The reactions with nitrogen-14 lead to the formation of carbon-14,
widely used in radiocarbon dating.
• https://en.wikipedia.org/wiki/Neutron_radiation

4. Neutron radiation: Radiation Protection.
• In health physics neutron radiation is a type of radiation hazard. Another,
sometimes more severe hazard of neutron radiation, is neutron activation, the
ability of neutron radiation to induce radioactivity in most substances it
encounters, including the body tissues. This occurs through the capture of
neutrons by atomic nuclei, which are transformed to another nuclide, frequently
a radionuclide. This process accounts for much of the radioactive material
released by the detonation of a nuclear weapon. It is also a problem
in nuclear fission and nuclear fusion installations as it gradually renders the
equipment radioactive such that eventually it must be replaced and disposed of
as low-level radioactive waste. https://en.wikipedia.org/wiki/Neutron_radiation
• http://www.slideshare.net/dlpopov/induced-radioactivity
• http://www.intechopen.com/books/current-topics-in-ionizing-radiation-
research/radiation-toxins-molecular-mechanisms-of-toxicity-and-radiomimetic-
properties-

5. Neutron radiation: Radiation Protection.
• Due to the high kinetic energy of neutrons, this radiation is considered to
be the most severe and dangerous radiation to the whole body when it is
exposed to external radiation sources.
In comparison to conventional ionizing radiation based on photons or
charged particles, neutrons are repeatedly bounced and slowed (absorbed)
by light nuclei so hydrogen-rich material is more effective at shielding
than iron nuclei. The light atoms serve to slow down the neutrons
by elastic scattering so they can then be absorbed by nuclear reactions.
However, gamma radiation is often produced in such reactions, so
additional shielding has to be provided to absorb it. Care must be taken to
avoid using nuclei which undergo fission or neutron capture that results
in radioactive decay of nuclei that produce gamma rays.
• https://en.wikipedia.org/wiki/Neutron_radiation
• http://www.slideshare.net/dlpopov/induced-radioactivity

6. Neutron radiation: Radiation Protection.
• Neutrons irradiation produce a unique biological effectiveness
compare to different types of radiation because their ability to create
a denser trail of ionized atoms in biological living tissues
• Straume 1982;
• Latif et al.2010;
• Katz 1978;
• Bogatyrev 1982.
• http://www.intechopen.com/books/current-topics-in-ionizing-
radiation-research/radiation-toxins-molecular-mechanisms-of-
toxicity-and-radiomimetic-properties-

7. Neutron radiation: Radiation Protection.
The efficacy of an Anti-Radiation Vaccine for the prophylaxis,
prevention and therapy of acute radiation pathology was studied in a
neutron exposure facility.
The biological effects of fast neutrons include damage of Central
Nervous system and Cardiovascular system with development of Acute
Cerebrovascular and Cardiovascular forms with acute radiation
pathology.
http://www.intechopen.com/books/current-topics-in-ionizing-
radiation-research/radiation-toxins-molecular-mechanisms-of-toxicity-
and-radiomimetic-properties-

8. Neutron radiation: Radiation Protection.
• After irradiation by high doses of fast neutron in irradiated tissues
started formation of toxins: neurotoxins, hematotoxins, cytotoxins,
which are forming from cell's or tissue structures.
• High doses of Neutron Irradiation generate general and specific
toxicity, inflammation reactions.

9. Neutron radiation: Radiation Protection.
• Current Acute Medical Management and Methods of Radiation
Protection are not effective against moderate and high doses of
neutron irradiation.
• Our experiments demonstrate that immunological reactions playin
extraordinary role in development pathological processes and
Antiradiation Vaccine is the most effective radioprotectant against
high doses of neutron-radiation.

10. Neutron radiation: Radiation Protection.
• Radiation Toxins(biological substances – enzymes and secretory
prooteins with radio-mimetic properties) isolated from central lymph
of gamma-irradiated animals are working substances with specific
antigenic properties for vaccination against neutron irradiation.

11. Neutron radiation: Radiation Protection.
• Antiradiation Vaccine preparation standard - mixture of a toxoid form
of Radiation Toxins - include
• Cerebrovascular RT Neurotoxin,
• Cardiovascular RT Neurotoxin,
• Gastrointestinal RT Neurotoxin,
• Hematopoietic RT Hematotoxin.

12. Neutron radiation: Radiation Protection.
• Radiation Toxins were isolated from the central lymph of gamma-
irradiated animals with different forms of Acute Radiation Syndromes
– Cerebrovascular ARS,
• Cardiovascular ARS,
• Gastrointestinal ARS,
• Hematopoietic forms ARS.

13. Neutron radiation: Radiation Protection.
• Devices for Y-radiation were "Panorama", "Puma".
• Neutron exposure was accomplished at the Department of Research
Institute of Nuclear Physics, Dubna, Russia.
• The neutrons irradiation generated in a canal of Research Reactor
BBP-M and BBP-M.
• Mixed neutron beam contained 95% of fast neutron irradiation and
5% of gamma-irradiation. Neutron energy - 1.98 - 2.30 Me V energy.
Dose - 10.7 Gy., 0.22 Gy-min.

14. Neutron radiation: Radiation Protection.
• Scheme of experiments:
• Rabbits from all groups were irradiated in a canal of Research Reactor
together.
• Group A: control-5 rabbits;
• Group B:placebo-5 rabbits;
• Group C: Radio-protectant Cystamine (50 mg-kg)-5 rabbits, 15 minutes
before irradiation
• Group D: Radio-protectant Mexamine (10 mg-kg)-5 rabbits { 15 minutes
before irradiation;
• Group E: Antiradiation Vaccine: subcutaneus administration or I/M - 2 ml of
active substance , 20 days before irradiation.

15. Neutron radiation: Radiation Protection.
• Results:
• Control Group A - 100% mortality within the next two hours after neutron
irradiation with clinical symptoms of acute cerebrovascular syndrome.
• Group B - 100% mortality less than two hours following irradiation. Group
C - 100% mortality within 8-10 hours after irradiation.
• Group D - 100% mortality within 8-11 hours after irradiation.
In Groups A - D the development of extremely severe form of Acute
Radiation Cerebrovascular Syndrome with outcome - rapid death.
• Group E - 100% mortality within 240 hours ( 9 -10 days) following neutron
irradiation and animals exhibiting cardiovascular, cerebrovascular and
gastrointestinal clinical symptoms.

16. Neutron radiation: Radiation Protection.
• Discussion:
• A pre-irradiation vaccination with Antiradiation Vaccine is effective
against mild and even high doses of neutron radiation.
Vaccination with antiradiation Vaccine prolonged survival time of
rabbits, exposed to a high dose LD100, of neutron radiation: from two
hours (control) up to 11 days. We also postulate that radiation toxins,
isolated from lymph of gamma-irradiated animals are likely similar to
structure of radiation toxins circulated in blood and lymph of neutron
irradiated animals.

17. Neutron radiation: Radiation Protection.
• Toxic-kinetics and toxic-dynamics of radiation toxins of after neutron-
irradiation were under research investigation and distinguished from
different types of radiation.