ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
August 2025
Fusion Science and Technology
Latest News
Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
K. V. Subbaiah, C. Sunil Sunny
Nuclear Technology | Volume 135 | Number 3 | September 2001 | Pages 265-272
Technical Paper | Radiation Protection | doi.org/10.13182/NT01-A3221
Articles are hosted by Taylor and Francis Online.
KAMINI is the Kalpakkam Mini Reactor, and its main purpose is to cater to experimental needs and for neutron radiography. It is a water-cooled reactor with 233U as the fissile material. Using the Monte Carlo n-particle transport code MCNP, shielding optimization calculations are carried out for the south beam port tube, which is meant for neutron radiography of spent-fuel subassemblies of the fast breeder test reactor. The neutron beam port is a graded cylindrical aluminium channel starting from the center of the reactor core; it pierces through the biological shield and is 2 m long. The diameter of the channel at the core center is 54 mm, at the other end it is 25 cm, and it is 0.5 m below the floor level. The latter end serves as the neutron surface source for these calculations. The calculations have been carried out in cylindrical geometry (r,z) of shield structures. From results of the analysis, a movable shield 50 cm thick (25 cm paraffin and 25 cm lead), 75 cm wide, and 172 cm long extending ~95 cm into the demineralizer room (cooling water purification room) is proposed to replace the existing temporary shield structure. In addition, fixed shields of the same thickness and width of 50 cm on either side of the beam is recommended to reduce the dose levels to a few tens of microsieverts per hour in the accessible areas. Further, the lead-shielded cylindrical tube meant for insertion of irradiated fuel subassemblies for neutron radiography needs to be covered with 20 cm of paraffin up to a height of 1 m from ground level to avoid streaming of neutrons through the air column.
