June 14, 1996
Mr. Morris Rosen
Deputy Director General
Head of the Department of Nuclear Safety
International Atomic Energy Agency
Dear Mr. Rosen:
Thank you for your letter of March 25 in response to the letter of February 26 we sent to Director General Blix regarding concerns about the adequacy of the special requirements being established for air transport of radioactive materials. The assurances your technical staff has provided you that "significantly more rigorous requirements will be imposed for (air) transport of such materials" in the pending revision of IAEA Safety Series 6 (SS6) do not address the specific concerns we raised with Dr. Blix and do not allay the deep sense of amazement and outrage we expressed to him.
A principal objective of the current revision of SS6---to deal realistically with the unique hazards and potential consequences of air- transport accidents (as distinguished from road, rail or sea-transport accidents) involving radioactive materials---are defeated in two ways: by the inadequate standards proposed for the strengthened ("Type C") packaging for air transport and by the obvious attempt to exempt fresh plutonium-uranium, mixed- oxide (MOX) fuel from this special package. The exemption of "low dispersible material" (LDM) from the requirement for Type C packaging is unproven and untested and all the more egregious because it is tailor-made to fit MOX fuel.
If indeed, as you express it, "strengthening international transport standards requires developing consensus on the need for improvements and the degree to which they are justified," you must not allow such consensus-building to be dominated by industry interests with a direct stake in the outcome---in this case, a plutonium industry that wants to move MOX fuel by air. For the reasons we elaborate below, it appears that precisely this perversion of the IAEA's regulatory process has taken place. It must be reversed before the revised SS6 is presented to the Board of Governors for final approval.
What follows is our response to the technical points you make in your letter, as well as our proposal for correcting the flagrant errors that are now built into the draft air-transport requirements:
Assertion: "The more stringent requirements include rigorous technical specifications to ensure that the transported materials are either of very low dispersibility and limited radiation hazard (LDM) or, that they be packaged in more accident resistant (Type C) packagings if the materials are dispersible."
Response: We address below the claim of rigorous technical specifications to ensure very low dispersibility and limited radiation hazard. Regarding the claim of accident resistance of Type C packagings, we refer you to the analysis commissioned by the International Civil Aviation Organization's (ICAO) Dangerous Goods Panel.
This safety review compared the tests for impact and fire for the proposed Type C packaging for radioactive materials with the international test specifications for flight recorders (the so-called "black boxes") such as those set by EUROCAE (European Organization for Civil Aviation Equipment). The ICAO analysis found that the input energy per unit mass associated with the IAEA Type C impact test (90 meters/second on an unyielding surface) was only 38% of the input energy associated with the flight recorder specification (corresponding to an impact speed of 130 meters/second on an unyielding surface). The Type C fire test (800C fire for 60 minutes) is also considerably less severe than the test required for flight recorders (1100C for 60 minutes)---the latter having been developed from the actual thermal conditions which have been experienced in accidents. In view of the fact that there have been accidents in which flight recorders have been breached, the demonstrated inferiority of Type C casks relative to flight recorders casts considerable doubt on the claim that Type C casks will be able to survive a realistic range of aircraft accidents.
Also, the IAEA Type C package requirements fall far short of the air transport packaging requirements of the U.S. Government. The U.S. impact test for a cask used in domestic flights is 129 meters/second (almost identical to the flight recorder specification), compared with the proposed IAEA test of 90 meters/second. For overflights of U.S. territory, an even more stringent impact speed of 282 meters/second is required. The U.S. also requires the same cask to undergo sequential impact and fire tests; the IAEA does not. The IAEA is prepared to allow separate casks to be used for the impact and fire tests on the assumption "high speed impact and long duration fires are not expected to be encountered simultaneously." In fact, high impact and extended fires have occurred simultaneously in severe air transport accidents, as was the case when an El Al cargo plane crashed into an apartment complex in Amsterdam at a speed of 335 mph (equivalent to 150 meters/second), causing an intense fire that burned for hours.
Assertion: "The technical specifications for demonstrating low dispersible material ensure that the material transported, when subjected to the same mechanical and thermal tests as a Type C package, produce only inconsequential dispersion. That is, the material itself, with no credit for its packaging, must meet these performance criteria."
Response: The maximum allowable airborne release of radioactivity from LDM, 100 A2 (consisting of particles with an aerodynamic diameter smaller than 100 microns) is not "inconsequential," as you claim, but far exceeds the maximum release of A2 (independent of particle size) in one week permitted by SS6 from a Type B package following a regulatory accident. The release of 100 A2 from a crash site therefore would result in a substantially higher number of radiation-induced injuries than is permitted by SS6 for accidents involving land-based transport modes. If consistency with the rest of SS6 is to be achieved, the LDM definition must implicitly assume that following an air crash, Type B casks will retain an integrity sufficient to reduce the release of radioactivity from its contents by a factor of at least one hundred. This is an extraordinary assumption for which there is no technical support.
Assertion: "Only then can such materials be packaged in the currently required Type B category of package, which has consistently demonstrated an ability to survive severe accidents."
Response: There is no evidence that a Type B package has any ability whatsoever to survive the extremely severe conditions characteristic of an air crash, since such packages are only tested to conditions typical of land- based accidents. Moreover, there is no provision in the current revision of SS6 requiring that a Type B cask, to be used for transporting LDM by air, demonstrate that it will be able to maintain a large part of its integrity following an air crash. In the absence of such information, one must assume that a release of 100 A2 from LDM will result in a release of the same magnitude to the environment.
Assertion: "The requirements for low-dispersible radioactive material which have been developed and included in the draft regulations are the performance and acceptance criteria that are believed to provide the necessary degree of non-dispersibility. It still remains to be determined whether mixed oxide fuels...can meet these stringent requirements."
Response: This statement ignores the evidence, referred to in the technical note attached to our letter to Dr. Blix, that the so-called "stringent requirements" are unjustifiable from a safety perspective and appear to have been cooked up expressly so that MOX fuel would satisfy them. Our conclusion is based on data cited in German safety reports that indicate that the amount of plutonium (contained in particles under 100 microns) expected to be released from MOX fuel following an air crash would be on the order of 100 A2.
Further, you ignore the fact that the nuclear industry does not share your agnosticism on whether MOX fuel will prove to be non-dispersible. It already treats MOX and LDM as if they are interchangeable terms. It is clear from the German proposal on LDM that MOX is the main, if not the only, candidate. Also, note the statement made by BNFL spokesman Gavin Carter in a recent Journal of Commerce article: "MOX is safer for air transport...it's low-dispersible." The IAEA should admonish BNFL for making misleading and unsubstantiated statements prior to issuance of an IAEA standard that presumably requires such an assertion to be put to the test before it can be stated as fact.
Assertion: "To the best of our knowledge, no test regimes and protocols have been completely developed by potential package designers to demonstrate how material can be tested to the very stringent performance and acceptance requirements. It is not possible to know which materials, if any, will qualify as LDM until the materials have been tested and the results accepted by the competent authorities of all countries involved in their shipment."
Response: The idea of applying Type C impact and fire tests directly to plutonium-containing materials is highly problematic from an environmental safety and health perspective. Such tests will require highly specialized and costly facilities and substantial development time; for these reasons, such testing will probably never be carried out. Instead, LDM demonstrations will likely be confined to computer models and/or tests on simulant materials. Neither of these approaches can convincingly reproduce phenomena specific to plutonium, since it exhibits complicated oxidation and migration behavior in heated MOX fuel. Also, such tests are unlikely to accurately simulate the vaporization behavior of americium, which may exist in substantial concentrations in fresh MOX fuel.
Conclusions and recommendations: It is disheartening that a decade- long process to establish discrete and realistic air-transport safety requirements for radioactive materials has produced such disappointing and counter-productive results. In our view, the entire exercise raises serious questions about the relationship between the IAEA and the nuclear industry and about whether regulation in the interest of public health and safety can emerge from the present relationship.
The solution in our view---for the good of the Agency as well as for the public at large---is for the draft SS6 to be submitted for review by a special panel of the IAEA Advisory Commission on Safety Standards (ACSS) whose membership would exclude representatives of industry and government bureaucracies with a special interest in the promotion and use of MOX fuel, and include representatives of the International Civil Aviation Organization (ICAO), the International Air Transport Association (IATA) and the International Federation of Air Line Pilots' Associations (IFALPA).
This panel should establish impact and crash-resistance criteria based on the most severe aviation accidents (examples: the El Al crash in Amsterdam in 1992 and the crash of Pacific Southwest Airlines flight 1771 in California in 1987).
In addition, because of the difficulties noted above in testing MOX to demonstrate non-dispersibility, the LDM exemption from Type C packaging should be eliminated altogether.
We believe it is in the highest public interest that plutonium not be allowed to be flown internationally on the basis of the presently proposed IAEA standard for a cask that could not survive a high-velocity crash and for an exception that would allow MOX fuel to be flown in even weaker casks. Since the proposed SS6 revision is now before the ACSS, prior to being submitted to the IAEA Board of Governors for final approval, we will be circulating this exchange of correspondence on this urgent matter to members of the IAEA's Advisory Commmission on Safety Standards and Board of Governors, and to the international aviation organizations named above.
Paul L. Leventhal
Edwin S. Lyman
cc: Chair and members, IAEA Advisory Commission on Safety Standards
Chair and members, IAEA Board of Governors
Dr. Assad Kotaite, President of the Council, International Civil Aviation Organization
Pierre J. Jeanniot, O.C., Director General, International Air Transport Association
Captain L.H.D. Bakker, President, International Federation of AirLine Pilots Associations
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