' 7,||;;?3.-IAMBoeht.l. ' UNIVERSITY OF CALIFORNIA, BERKELEY

BERKELEY * DAVIS * IRVINE * LOS ANC1LES * RIVERSIDE * SAN DIECO * SAN FRANCISCO SANTA BARBARA * A CRUZ

COLLEGE OF ENGINEERINC DEREELEY, CALIFORNIA 94720 DEPARTMENT OF NUCLEAR ENGINEERINC *8g {{Q jQ hI!47

:.F 6 00D 5 February 1986 !"

Secretary of the Commission U. S. Nuclear Regulatory Commission Nashington, DC 20555 Attn: Docketing and Service Branch

Re: Comment on Proposed Ruies for 10 CFR 19 et al.

Dear Sir or Madam: Please refer to the definition of the sievert, in Section 20.4 (4), on page 1127 of the proposed rules for 10 CFR 19 et al. Contrary to your statement, the sievert is NOT in general equal to a Joule / kilogram. The definition, if uncorrected, will cause confusion and could result in erroneous measurements. At the same time, I can understand how your definition was taken verbatim from some presumably reliable source. I am enclosing a recent letter-to-the-editor in Nuclear News which refers to the history of the defective definition. I am also enclosing a page from a 1985 NCRP Repor t which correc tly discusses the definition of the sievert.

| Insofar as revised wording is concerned, I suggest that ! since you have exhaustively defined the rem, it is only aecessary further to say,

( 4) " Sievert" (Sv) is G60211OOS4 G60206 a unit of dose equivalent. PDR PR One sievert is equal to 19 SOFR51992 I>UH 10 0 r ems .

Please understand that the opinions expressed in this comment are my own, and are not represented to be those of | the University of California.

g Sincerely

j j Uh ? /kO ctf K St G ||?)0) 0 / ' &jjj N/1)$10f QQC4f9Ml!~'i6 \ -+' ... Lawrence Rbby ,~ t t, 90 Professor , * . , ...... 'd ,, _

, ,- ~ fuel oil, typically saving about $300,- ' Action on th3 sievert ...d.,. ., t, p.g wi,1 r o,, t P., ,..r. e ~' .ers the controversy (see NUCLEAR News, EBR-II is a liquid-metal fast breeder May 1982, p. 74) over the definition ctor with a thermal rating of 62.5 of the sievert as specified by the 16th t and an electrical ratmg of 20 General Conference on Weights and M 'e. For expenmental convenience, Measures (CGPM). Discussion in this th electrical production is now about and other journals, plus the intercession 17 MWe, of which about 5 MWe is of many professionals, finally con- consumed un the Argonne-West site; vinced U.S. government authorities the remainder goes out on the elec- that a problem did, in reality, exist. trien! grid of the Idaho National Engi. Hence, in the latest edition of NBS neciing Laboratory (INEL), which is Special Publication 330, there appears servrd by Idaho Power Company. (At a clarifying paragraph following the times of low power usage on the INEL, wording adopted by the 16th CGPM. EBbil puts out a surplus of power Although the controversial defic tion that goes to non.INEL Idaho Power Outcries explained t is a scant nine words ("ne sievert is customers.) , With reference to the lett< r by equal to the joule per kilogram."), the I?uring the maximum winter-heating Meyer Steinberg on page 33 is the clarification requires about 100 words months, EBR II also furnishes up to 14 (00 lb/h of steam for space heat- May 1985 issue of NUCLEAR NEWS: If to set the meaning straight. Readers , Israel considers itself at war wit $ Iraq will enjoy hearing that a similar patch ing nd plant uses; this is equivalent and wishes to bomb Iraqi researth in- job has been proposed for the inter. to bout 1 MWt. In summer, the stitutes and industrial installationn, that national scene. Last June, the Consulta- requ ement for reactor steam drops is not unusual for a country at war- tive Committee on Units (CCU) pro- belo * 5000 lb/h. - I regret that any country is ever i t war posed to the International Committee ne reactor steam is taken upstream with another, but usually refrain from on Weights and Measures (CIPM) that of tile turbine at a pressure of 1250 comment on the way that war is con- because a "possible confusion" exists psig. and is reduced to 100 ps,gi for ducted, provided the Geneva ccnven- with respect to the difference between plani and space beating uses. The tion is followed- the gray and the sievert, in that they maximum reduction in electrical out. The outcry by many people, hclud- both have been defined as formally put electricity, this writha was not at this bombin g, but the resolutions adopted by the CGPM has been a very economical trade.off at two other features. First, representa- regarding the gray and the sievert. The for Argonne National Laboratory, the tives of the State of Israel-which, b) number of words in the French text of operator of EBR II, and also for the not signing NPT, has rejectei the the footnote is again about 100, and it taxpayers. mithod accepted by a majority af the makes use of the noble phrase, "Alin In 1980 EBR II was granted the nations of the world--cogeneration they were doing the world a s rvice In the view of this write a pr"5 in facih y by the Federal Energy Regula- by preventing the proliferation o nu- lieu of a corrected defin; ad rep. tory :ommission-the first, and so far clear weapons. That claim was rej cted resent progress of a sor and nor this, the only, such certification of a nuclear by most of the world, and the ter- we should be appreciar . .: of the efforts reactor in the United States. citional Atomic Energy Agene in of the U.S. represec' ave to the CCU, f Adrian E. Allen p rticular, and I believe the invers is David T. Gold" Senior Technical Editor true. Second, airplanes supplied by he L wrence Ruby Argonne National Laboratory United States for defensive purpo s Idaho Falls, Idaho only were used. Ahhough delivery Professor, Department of Nuclear further planes was initially halted, th Engineering U.S. Senate later condoned this use by College of Engineering University of California t.!!owing further delivery and thereby Correction redeSned defensive purposes. Berkeley, Calif. Iraq ts at war with Iran-with an words not very in a report o, the active, shooting war. That Iraq should recent Seminar on Probabilistic disk decide to bomb a power station should EBR Il as a cogenerator Assessment (PRA) on page 116 of the engender no surprise. Moreover, the Your article on " Combined beat and May issue completely changed the tirplanes used were not provided free power" by Eric Jeffs (NN, Apr.1985, meaning of the point that IAEA's or under loan by another country with p. 91) correctly listed no utility-owned Deputy Director, leonard Konstan- m n hs ago I rote to friends CHP plants ,in the United States. How- tinov, was attempting to make. Dis- . ever, there is one near-exception that cussing the results of 22 PRA studies m Iraq expressing my horror at the I would like to bring to your attention. to the end of 1983, he suggested that reported use of poison gas by Iraq. Experimental Breeder Reactor 11 comparing core. melt frequencies was I am told that ti.e letter was forwarded , (EBR II), although owned by the not very meaningful because factors to the responsible authorities. I am Department of Energy and not a utility, such as differences in plant design, writing again to express my concern at is commonly operated in intertie with operation, and site characteristics con- the stupidity of bombing the power the Idaho Power Company grid. Since tributed differences as great as three station at Bushehr. 1974, EBR II has also furnished re- orders of magnitude. PRA (or " Prob- Richard Wilson actor steam for space heating and abilistic Safety Assessment," as Kon- Mallinckrodt Professor of Physics plant steam at the Argonne National stantinov prefers it) was nevertheless Chairman, Department of Physics Laboratory-West site. This reactor significant in establishing the relative Harvard University steam has replaced steam that would importance of systems that might con- Cambridge, Mass. otherwise have been produced with tribute to core melt.

NUCLEAR NEWS / JULY 1985 21 g . _ - - _ . - _

, . , 16 / 3. CONVENTIONAL AND SI IJNITS 3.3 DOSE EQt?iVALENT / 1 Calculation in InternationalSystem units confusion since it may obscure the differences among the quantitie Calculate the exposure rate at 3 meters from a 1 TBq source. * ' l'. = 2.53 x 10-'" C kg-' m' s-' Bq-' * # '# #9" "' # " '" 10,, Bq The fluence rate of neutrons at middle latitudes and sea leve X. = 2.53 x 10-'' C kg-' m2 s-' Bq-8 x produced by the insteraction of cosmic radiation with the earth' (3m)2 atmosphere may be taken as 7 x 10-8cm-8 s - '. Calculate the maximus = 2.81 x 10-7 C kg-' s-'. dose equivalent in a semi. infinite tissue. equivalent slab from a year exposure to cosmic ray neutrons. Calculation in conventional units For the casmic ray spectrum the fluence-to. dose equivale 3.3 Dose Equivalent conversion s taken as (Shaw et al 1969): The quantity dose equivalent is defined by the ICRU (1980) as H/+ = 1.27 x 104 rem cmt follows: The dose equivalent, H, is the product of D, Q, and N at the This is based on the annual maximum dose equivalent in the 30.cr point of interest in tissue where D is the absorbed dose, Q is the thick slab from cosmic ray neutrons. Remembering that the numbe quality factor and N is the product of all other modifying factors, of seconds in one year is about 3.16 x 10', this becomes: # = DQN. 11 = 7 x 10-' cm-2 s- * x 1.27 x 10-* rem em' The special name sievert, symbol Sv, has been adopted for the Si x 3.16 x 10' s unit of dose equivalent in the field of radiation protection. For a given irradiation, the numerical value in joules per kilogram for the two = 2.8 x 10-3 rem. quantities D and H may differ, depending on the values of Q and N. Calculation in SI units To avoid any risk of confusion, the special names for the respective units should be used; i.e., D should be expressed in grays and 11 should Recalling that there are 10* cm2 in one m*, the annual fluence o be expressed in sieverts, cosmic ray neutrons is: 1 sievert = 100 rem. + = 7 x 10-8 cm- - ' s ' x 10* cm8 m-8 x 3.16 x 107 s Further ICRU reports which are helpful in understanding the = 2.21 x 10' m-2 definition of the quantity " dose equivalent" are ICRU Report 33 entitled Radiation Quantatics and Units (ICRU,1980), and ICRU The fluence to dose equivalent conversion. H/+, for the spectrum o cosmic ray neutrons is: Report 25 entitled Conceptual Basis for the Determination of Dose Equivalent (ICRU,1976), and ICRU Report 39 entitled Determination H/ + = 1.27 x 10-'' Sv m2 , of Dose Equivalents Resulting from External Radiation Sources (ICRU' and the annual dose equnvalent is 1935). An absorbed dose of I rad from photons results approximately in a H = 2.21 x 10' m-r x 1.27 x 10-'' Sv m' dose eqmvalent of I rem. This leads to the numerical relationship that = 2.s x 10-5 Sv = 26 pSv. an exposure of 1 R to soft tissue produces approximately an absorbed dose of I rad and a dose equivalent of I rem. This convenient " rule of Comparing the two calculations and remembering that 1 Sv = li thumb' associated with conventional units. however, can lead to , rem we see that they are in agreement.

"SI Units Radiation3 Protection and Measurements", NCRP Report No. 82, ]985 in