Book Review: Radiation Protection for Particle Accelerator Facilities
Radiation Protection for Particle Accelerator Facilities, NCRP Report No. 144, 2003, 499 pp. (hardcover), $105.00, National Council on Radiation Protection and Measurements, 7910 Woodmont Avenue, Suite 400, Bethesda, MD 20814-3095; ISBN 0-929600-77-0
National Council on Radiation Protection and Measurements (NCRP) Report 144 replaces the previous Report 51, which was published in 1977. The scope of this volume of about 500 pages covers all particle energies larger than 5 MeV (in the old report the range was between 0.1 and 100 MeV). A major difference with respect to Report 51, which was concerned only with accelerator shielding design, is represented by the presence of extensive information about radiation measurement techniques and environmental radiological aspects. There is also a chapter on operational radiation safety, but unlike the other chapters it seems rather superficial and does not contain much useful information; an opportunity regrettably missed, because this is a subject on which it is difficult to find good guidance and opinions often diverge, for instance on the use of programmable logic controllers.
The other chapters are much more exhaustive and useful, although it is easy to recognize a lack of uniformity, which probably reflects the contributions of different authors. These are all well-known and respected experts in the field, and for somebody familiar with the matters treated it is easy to recognize the signature of most of the individual authors. The fact that not all authors are still active professionally can perhaps explain why some parts are not fully up-to-date with the most recent advances in the field. This is not the case with the chapter on radiation measurements--the best part of the report in my opinion--where all recent important developments are described. Only the cross sections reported are far too old, and much better data can be easily found on the International Atomic Energy Agency (IAEA) or National Nuclear Data Center (NNDC) websites.
The remaining chapters, on shielding design and environmental radiation protection, could be considered as a compendium of the state of the art in accelerator radiation protection before the last decade of the 20th century. But the last 15 years have seen a revolution, mostly due to progress in computer technology, which has completely changed everybody's daily life in general and shielding design in particular.
It is indeed a real pity to give up elegant mathematical techniques such as the Spherical-Harmonics method, or to ignore the knowledge that has been embodied for so many years in famous models (Moyer integrals) or books (W.P. Swanson). But nowadays one gets much better and more complete results using Monte Carlo codes, and big shielding projects at the European Organization for Nuclear Research (CERN), Stanford Linear Accelerator Center (SLAC), or Fermi National Accelerator Laboratory (Fermilab) are handled entirely by means of computers.
Simple formulae and basic data are still useful for quick order-of-magnitude estimates, but when their use requires large and complex tables (e.g., the neutron and photon importance tables in an annex of the report), a direct computer simulation seems much more straight-forward and accurate.
This is not to say that computer codes have been ignored in the report. A good survey of most of the codes currently used in shielding design is present and up-to-date as far as it is possible in this field, which is developing very fast. But too many tables and figures report data that are more than 30 years old and that could be easily updated using a good modern Monte Carlo code and recent experimental data.
A side comment concerns the perpetual re-use from review to review of old figures (many taken from Swanson's book), which according to present knowledge are incorrect, even in a qualitative way. There are many such figures in NCRP 144: I will mention as an example Fig. 4.19, on page 200, where the plotted photoneutron cross section has only a very remote resemblance to reality.
Despite the weaknesses stressed above, there are many useful pieces of information in the report, and I am sure that every accelerator health physicist will mark some of the pages to find quickly some favorite formula or curve.