Thorium

We developed a new method of brachytherapy, termed diffusing alpha-emitters radiation therapy (DaRT), based on the use of intratumoral (224)Ra-loaded wires, which release short-lived alpha-emitting atoms by recoil. Here, we examined their ability to destroy and control the development of several human-derived tumors implanted in athymic mice. The experiments were performed on athymic mice bearing malignant human-derived tumors including prostate (PC-3), glioblastoma (GBM, U87-MG), colon (HCT15), squamous cell carcinoma (FaDu) and melanoma (C32). One or more (224)Ra-loaded wires were inserted into the tumors, and mice were assessed for tumor growth rate and survival. In vivo studies showed that DaRT can effectively destroy the tumors, and in vitro tests confirmed the sensitivity of the studied cells to alpha particles. While the C32 cells were relatively resistant, other tumor types (e.g. HCT15) exhibited sensitivity in both measured aspects. DaRT could potentially be combined with c...

Radionuclide concentrations of beach and dune sand from various sites in Al-Arish city and surrounding area, North Sinai, Egypt, were measured. The sampling sites included locations in the local harbor, Al-Arish valley and Zaranik protected area. The results indicate that the activities of the products of 232Th and 226Ra series in samples from the harbor and along the beach were higher than those from non-coastal sites. The activity concentrations of 232Th for beach sand ranged from 2.3 to 506.5 Bq/kg with an average of 83.4 Bq/kg, while that for dune sand ranged from 2.2 to 15.1 Bq/kg with an average of 6.4 Bq/kg. The average activity concentration of 226Ra for beach sand was 56.0 Bq/kg (2.9–261.5 Bq/kg), while that for dune sand was 6.5 Bq/kg (3.0–14.7 Bq/kg). The average activity concentrations of 40K for beach and dune sand were 88.1 Bq/kg and 178.4 Bq/kg, respectively. Six depth profiles in the harbor area were measured up to a depth of 1 m within more than two years. These sets of measurements allowed the determination of the migration rate of black sand to be 0.094 cm/day. Samples with the smallest grain size (<0.2 mm) were found to have the highest level of activities, which were attributed to their high content of black sand.No risk exists for public health based on the calculated effective dose equivalent and the recommended limit of 5 mSv/y. On the other hand, local children and adults may receive doses higher than this recommended limit in two locations in the Zaranik protected area according to a model developed in this study.

The article concerns the possible destination of the complex commonly known as RIESE, located in Lower Silesia, Poland. It presents some facts as well as evidence of the validity of the thesis put forward by the author that the RIESE complex was a secret center of nuclear research of the Third Reich. This is evidenced, inter alia, by the analogies between the RIESE facilities and similar facilities existing in later periods related to nuclear projects of the USA and Russia.

Mr. Campbell and Dr. Conca provided one of the 10 summaries for energy resource commodities on uranium, thorium, and rare earths (pp. 450-458). Other experts provided sections on geothermal, coal and unconventional energy resources, and on an analysis of energy economics and technology, all prepared by
committees of the Energy Minerals Division of the American Association of Petroleum Geologists. Unconventional energy resources, as used in this report, are those energy resources
that do not occur in discrete oil or gas reservoirs held in structural or stratigraphic traps in sedimentary basins. Such resources include coal-bed methane, oil shale, uranium and thorium
deposits and associated rare-earth elements of industrial interest, geothermal, gas shale and liquids, tight gas sands, gas hydrates, and bitumen and heavy oil. Current U.S. and global
research and development activities are summarized for each unconventional energy resource commodity in the topical sections of this report, followed by analysis of unconventional
energy economics and technology.

The purpose of this paper is to assess fatal cancer risk after external and internal (inhalation and ingestion) exposure from natural radionuclides in soil like (238)U, (232)Th, (40)K, and (226)Ra on the territory of Bela Crkva, Serbia. Although receiving doses are low from sources like natural radionuclides in soil, because of stochastic effects of ionizing radiation, risk for developing cancer exists and can be quantified. Concentrations of radionuclides from 80 soil samples are measured using HPGe detector. Fatal cancer risk is assessed from calculated ambient dose rate in the target organs of body due to external and internal exposure. Monte Carlo simulations are used to obtain conversion factors which are required to calculate absorbed dose rate in target organs. Assessed cancer risk for (238)U in the case of both inhalation and ingestion exposure is from 1.11 × 10(-6) to 24 × 10(-6) for minimal and maximal activity in soil samples, from 1.02 × 10(-6) to 23.3 × 10(-6) for exposure to (226)Ra, from 1.89 × 10(-6) to 50.3 × 10(-6) for exposure to (232)Th, and from 0.265 × 10(-6) to 9.83 × 10(-6) for exposure to (40)K. Overall risk from (40)K as external and internal source is from 0.8 × 10(-6) to 31.9 × 10(-6). Calculated cancer risks from both inhalation and ingestion exposure could be related to all tissues that are on the way of distribution of particles within the body but especially to deposition sites in the body. Assessed risks for fatal cancer development from inhaled and ingested natural radionuclides originating in soil are not increased.

Nuclear power to be sustainable requires the fulfilling of peculiar constraints, which include addressing the proliferation risk. One possible route for sustainability is that to adopt a fuel cycle based on thorium. However, comparison with uranium cycle indicates that thorium cycle utilization is premature. Instead, a promising short-term option is the use of inert matrix fuels, possibly containing thoria, in a once-through cycle. Irradiation tests performed in the Halden reactor show encouraging behaviour under irradiation. Furthermore, these fuels are very well suited for a direct disposal in a geological repository.

Nuclear power still plays an important role for reducing CO 2 emission. At the same time, small scale and small capacity reactors, such called " small modular reactor (SM R) " is the recent trend of developing as new generation. On the other hand, molten salt reactor (M SR) is remarked as safe, high economy way as nuclear power. There are numbers of new proposals of M SR both for large and small capacity reactor in these just a few years. The author's proposal named " UNOM I (Universally operable molten salt reactor integrated) " is also among such small capacity M SR. In this paper, these new designs of M SR are reviewed from a view of engineering feasibility.

EXECUTIVE SUMMARY:
The two primary objectives of this report are:
1. to alert the members of the Energy Minerals Division, of AAPG and the
general public on the supply side regarding current activities within the
uranium, thorium, and rare-earth industries in terms of prices, exploration, and environmental issues, and
2. to assess the impact of uranium production cuts in Canada and Kazakhstan and the role Russian-owned companies have in the U.S. uranium mining industry and now in supplying uranium to U.S. utilities.
 Some 99 Nuclear power plants in the U.S. remain in operation, a few are scheduled for retirement, two new reactors are being completed in Georgia.
 The U.S. is the world's largest producer of nuclear power, accounting for more than 30% of worldwide nuclear generation of electricity.
 The U.S. produced about 4,015 billion (kWh) of electricity at utility-scale facilities in the U.S.
 Currently, about 63% of the U.S. electricity generation is from fossil fuels (coal, natural gas, petroleum, and other gases). About 20% was from nuclear energy, and about 17% was from renewable energy sources, including hydroelectric power plants.
 Following a 30-year period in which few new reactors were built in the U.S., it is expected that two more new units will come online soon after 2020; others resulting from 16 license applications made since mid-2007 are proposing to build 24 new nuclear reactors, most of which are of the new SMR design.
 The first zero-emission credit programs have commenced, in New York and Illinois.
 The years 2015 and 2016 exhibited the highest annual growth in nuclear plant capacity in 25 years,
 Significant uranium production cuts were made in 2017 from world’s largest uranium producers,
 Uncovered utility demand reaches ~24% by 2021 and 62% by 2025,
 Sustained low-price of uranium indicate that few new sources of supply are on-line, but a number of mines are either on stand-by or are available for development,
 Uranium holdings could be of strategic interest in the event of uranium supply interruption,
 U.S. utilities looking for risk-free ways to acquire significant supplies for future (likely Canada),
 Implied current yellowcake value is lower than many mine’s cost of production,
 Most of the uranium purchased by utilities is contracted (based on the long-term price: currently $31.00/lb U3O8),
 Saudi Arabia plans to build 16 reactors by 2030 with first reactor to come online in 2022;
 South Korea currently operates 25 reactors providing 33% of South Korea’s power, and is building reactors on budget and on time for UAE.
 Japan is upgrading and re-starting most of its fleet of nuclear power plants after Fukushima.
 China plans to build 99 reactors by 2030, with government investment of over $100 billion. Current position: 38 reactors in operation, 20 under construction, 39 planned/proposed for 240 total reactors on the horizon.
 China is rapidly building some 25 new plants and hundreds more are planned along with financially underwriting the construction of more than 40 projects in joint ventures with other countries.
 Russia currently has seven reactors under construction at home; An average of one large reactor per year is due to come on line through 2028,
 Russia is testing a “fast breeder” design that consumes most waste.
 Russia also is building nuclear plants in other countries as well, and providing financing.
 Russia is considering banning uranium sales to U.S. utilities because of the sanctions and tariffs applied by the U.S.
 Russia also is building a floating nuclear power plant for use along the coast of Siberia and for Sudan.
 India has turned to nuclear power to ramp up electricity production to match population growth rates and is also working on “fast breeder” designs.
 India plans to be 25% nuclear-energy-powered by 2050.
 Many other countries are also building nuclear plants funded by a variety of sources.
 There have been numerous discoveries of high-grade uranium deposits in Canada and new low-grade deposits reported to be under development in Argentina and Peru.
 Senior U.S. uranium industry personnel indicate that mining in Texas might not be re-initiated for a number of years because of the low uranium prices.
 Many uranium companies drilling new and established properties to establish an in place resource base in preparation for development sometime in the future.
 With hundreds of new nuclear power plants under construction in the world, it is only a matter of time until additional uranium supplies will be required, which will have to put pressure on the uranium price to increase substantially after 2020 and beyond.
 New data from ISS indicate that based on studies of astronauts, genes in humans are “turned on” in space, and remain on after returning to Earth while others return to “normal”.

Nuclear power will be used continuously as low-carbon energy for a sustainable society. On the other hand, prime attention is inclined to thorium molten-salt reactor (MSR) in recent years due to necessity for radioactive waste disposal, nuclear non-proliferation ("world without nuclear weapon") and higher safety of nuclear power. Thorium MSR is a type of liquid-fueled reactor utilizing thorium as fertile with some fissile materials contained in molten-salt. Research and development (R&D) of MSR started in the 1950s at Oak-Ridge National Laboratory (ORNL) for aircraft reactors. R&D activities were later extended to develop civilian power reactors using thorium, a concept which was completed in the 1970s. Nonetheless, technical problems still remained, such as temperature reactivity coefficient, material corrosion, and tritium permeation at heat exchanger. Since the 1980s several R&D activities to circumvent these problems have been done inside and outside ORNL. The problems relating to thorium MSR and recent R&D activities will be introduced in this paper.

Turkish coal is generally poor quality and the levels of chemical and radiological toxic trace elements in it are higher with respect to mean values of activity concentrations given in United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) Report. The main pathways through which the population living around soal-fired power plant (CFPP) is exposed to natural radionuclides are external and internal (ingestion and inhalation) dose and fly ash particles are the major component of the risk. It is estimated that the people working or living near the CFPP in Turkey receive a dose in between 0.1 mSv to 1 mSv extra from CFPP because nearly all the region of Turkey uranium (U) and thorium (Th) content in the coal are higher than 5 ppm to 7 ppm and around 25 ppm to 40 ppm respectively. Continuous monitoring is essential to determine occupational exposure levels in all stages of the coal fuel-cycle and proper measures should be taken to prevent direct contact of the ash pile with the top soil and local drainage systems.

Preceramic human skeletal remains preserved in submerged caves near Tulum in the Mexican state of Quintana Roo, Mexico, reveal conflicting results regarding 14C dating. Here we use U-series techniques for dating a stalagmite overgrowing the pelvis of a human skeleton discovered in the submerged Chan Hol cave. The oldest closed system U/Th age comes from around 21 mm above the pelvis defining the terminus ante quem for the pelvis to 11311±370 y BP. However, the skeleton might be considerable older, probably as old as 13 ky BP as indicated by the speleothem stable isotope data. The Chan Hol individual confirms a late Pleistocene settling of Mesoamerica and represents one of the oldest human osteological remains in America.

9N 6E Sec. 11 SBM 34.88333999990 -116.31752 (Eastern Exposure)
9N 6E Sec. 16 SBM 34.86811000030 -116.36026 (Western exposure)

Location: SW1/4 of Sec. 16, T.9N., R.6E., SBBM, San Bernardino County (Southern Pacific, 1964, p. 155; Coonrad, 1958-a2).

The pegmatite is located near the top of the ridge in the SW¼ of Section 16, as shown on the geologic map (Coonrad, 1958-a2).
The Hoerner-Ross pegmatite, in central San Bernardino County, is on the east side of the crest of a nearly conical peak south of the main ridge of the Cady Mountains; the Cady Mountains are an isolated mountain unit approximately 5 miles wide in e. northerly direction and 9 miles long in an easterly direction The peak is 7 miles N. 56o E. of Hector station on the Santa Fe Railroad Hector station is 30 miles east of Barstow. The pegmatite is accessible by a desert road 3 miles east from Hector, north under a railroad bridge, then 6 miles northeast up a wash to the east side of the peak. It also may be reached by travelling another desert road north from Hector for about 2 miles, then east 4 miles to a wash, and then up the wash to its end, which is another 4 miles from the east-west road. From the end of the wash, a steep trail rising 700 feet vertically over a horizontal distance of about 2,500 feet, leads up the bare ridge to the deposit (Walker and others, 1956, p. 21).

GEOLOGY
The pegmatite mass is less than 100 feet long and has a maximum width of less than 25 feet. Feldspar and quartz are the major constituents. Minor lense-like bodies of mica and nodules of magnetite are present as accessory minerals. In the lower part of the pegmatite are some lenses of material that contain a small percentage of the radioactive minerals strueverite, cyrtolite and betafite (?) (Walker and others, 1956, p. 21)(Coonrad, 1958-a2).

The deposit was initially described by Hewett and Glass (1953, p. 1040-1050), wherein they also gave radioactive dating results (155 million years, Middle Jurassic). Walker and others (1956, #69, p. 21) give a complete and concise description of the deposit (copy attached, Appendix “A”) (Coonrad, 1958-a2).

The pegmatite is considered a noneconomic occurrence of geological and mineralogical interest only. (Coonrad, 1958-a2).

The main scope of this paper is to point out the importance of introducing radon and thoron exhalation measurements from building materials in the regulating frame. Currently (2009), such a regulation of this kind of exposure is not explicitly included in the Serbian regulating network. To this end, this work reports concentration measurements of 226Ra, 232Th and 40K and radon and thoron exhalation rates from building materials used in Serbia. Following detailed analysis, it was noticed that both internal exposures to radon and/or thoron exhaling from building materials may exceed external exposures to their precursors contained therein.