ML20211P685
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| Issue date: | 06/30/1986 |
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IMPLICATIONS OF THE CHERNOBYL-4 ACCIDENT FOR NUCLEAR EMERGENCY PLANNING FOR THE STATE OF NEW YORK .
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Prepared For The STATE OF NEW YORK CONSUMER PROTECTION BOARD
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! June 1986 I .
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MHB TECHNICAL ASSOCIATES ,
j 1723 Hamilton Avenue, Suite K San Jose, California 95125 j
(408) 266-2716 e
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'. 8607230330 860616 4
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4 IMPLICATIONS OF THE CHERNOBYL-4 ACCIDENT FOR NUCLEAR EMERGENCY PLANNING -
FOR THE STATE OF NEW YORK 4
Prepared For The STATE OF NEW YORK CONSUMER PROTECTION BOARD MHB Technical Associates 1723 Hamilton Avenue, Suite K San Jose, California 95125 l'
(408) 266-2716 I. OVERVIEW On April 26, 1986, the most severe nuclear power plant accident to date occurred at the Chernobyl-4 nuclear power station, located in the Soviet Union aiong the Oneiper River approximately 60 miles from the city of Kiev. The reported death toll from the accident is currently twenty-three, with more
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deaths due to radiation exposure likely to occur in the next i several months. Approximately 92,000 people have been evacuated from the area within an 18-mile radius of the reactor site.
Radioactivity from the damage core has spread through the Soviet Union, Eastern and Western Europe, and beyond.
The societal impac,ts of the accident can be expected to be significant. The long-term health ef fects (e.g., latent cancers, genetic ef fects, thyroid nodules, are etc.) likely to be .
, substantial, but the magnitude of the impact cannot be accurately 1
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determined at this time. Contaminated foodstuf fs have been taken of f the market in Eastern and Western Europe. The* economic cost of the accident cannot be accurately quantified at this time, but appears likely to be in the range of tillions of dollars. In general, for a very large release of radioac tiv'ity (such as occurred at Chernobyl), it can be expected that long-term relocation of the population will be necessary for hundreds of square miles, and decontamination will be necessary to varying degrees for perhaps thousands of square miles. .
This paper is intended to review the lessons of the Chernobyl accident for the citizens of New York. The lessons of Chernobyl are particularly relevant because New York is "home" to a number of nuclear power plants t Indian ' Point Units 2~and 3, Nine Mile Point Units 1 and 2 (Unit 2 is under cons truc tion) ,
Fitzpatrick, Ginna, and Shoreham (now in low-power testing) . In addition, New York could be affected by accidents at a number of nuclear plants in other states.
This paper is based on what must be recognized to be limited and preliminary technical information, and sometimes -
contradictory reports, on the nature and course of the Chernobyl accident. As more becomes known about the accident, additional a
lessons beyond those discussed here may well be identified.
The paper is organized in eight sections. This " Overview" describes the purpose of the paper. Next, the nature of the Chernobyl accident is described. The third section of the paper briefly describes the salient design features of the Chernobyl-4 nuclear power plant.Section IV sets forth the various scenarios
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that have been proposed as possible causes of the Chernobyl accident. T$e next section of the paper presents the consequences of the accident. Section VI discusses emergency planning and reactor siting issues raised by the Chernobyl accident, while Section VII discusses U.S. nuclear accident.
Liability policies. Finally, the lessons of the Chernobyl accident are summarized. Briefly, these lessons are:
Lesson one: General design similarities in terms of containment and safety systems exist between Chernobyl-4 and many U.S. nuclear power plants, particularly boiling water reactors. These simila rities should be considered in reassessing the vulnerablility of U.S.
nuclear power plants to serious accidents. The need for such a reassessment is particularly great for pressure suppression containments. This conclusion places a premium on the prompt and thorough-going examination of the Fitzpatrick, Nine Mile Point Units 1 and 2, and Shoreham nuclear plants. _
Lesson Two: Catastrophic reactor accidents --
. resulting in very large releases of radioactivity --
are possible in U.S. reactors. Such accidents might be caused by inherent design deficiencies, lack of construction quality, human error, external events, sabotage, or multiple causes. New York State emergency h
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planning efforts should explicitly consider such serious accidents.
l Lesson Three: The long-term impac ts of radiation releases on agriculture, health, water, and the economy are likely to be more disruptive to society than the shor't-term impac ts . Unfortunately, current emergency plans place insufficient emphasis on long-term radiation safety measures. Both the early and long-term consequences of a serious reactor accident can be partially mitigated with an effective regional I
emergency plan which provides .for a variety of protective measures, including an extension of the current ten- and fifty-mile emergency planning zones.
New York state should also consider the need for emergency response for accidents at nuclear power plants in other states and at plants in Canada, since
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such accidents could require emergency response in 1
counties which do not now have radiological emergency -
plans to deal with the accident.
1 Lesson Fourt Emergency plans should be in place at all times for an operable reactor, regardless of whether the plant is undergoing testing, tempora rily out of service, or operating at full power. 1/
1/ Although Chernobyl-4 was at low power at the beginning of ,
the accident, the plant achieved initial criticality on
- December 14, 1983 (Walter Mitchell, III, Design Features of
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Lesson Five: State governments and regional Nuclear Regulatory Commission (NRC) offices should have an i:
automatic data link connecting them with nuclear power plant control room instruments to ensure prompt assessment of the severity of any potential nuclear 4
power plant accident. Such a data link would help reduce the potential for miscommunication of essential plant status and radiation release information in time i
of crisis. -
, . Lesson Six: The State of New York should ensure that adequate regional and/or federal capabilities are in place for tracking radioactive plumes, and for coordinating actions needed to interdic t potentially contaminated food and water supplies, and decontaminate potentially large af fected land areas.
Lesson Seven Remote siting should be required for new _
l nuclear power plants. Urban siting severely limits or renders impossible the prompt evacuation of the near-
. site population, which increases the potential for large early casualty tolls in the event of a serious the Sovter RBMK- L O O O/Che rn oby l-4 Reactor, report prepared for the U.S. Nuclear Regulatory Commission's Advisory 4
Committee on Reactor Safeguards, May 4, 1983), and had operated for some time at higher power levels. Thus, the i plant had doveloped a large amount of fission products and, as a result, a considerable decay heat inventory at the time i of the accident on April 26, 1986.
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accident. Further, urban siting increases the
) potential for societal disruption resulting from a serious nuclear accident since a la rger number of e
people would have to be relocated, and a greater level of economic activity would be disrupted. Existing urban-sited plants, such as Indian Point, merit special review of containment adequacy. Improvements can be made to strengthen the ability of existing containments to withstand accidents and minimize releases. Plans should be developed for the orderly phase out of plants which cannot be adequately improved in this regard. In the interim, strengthened inspection and enforcement measures should be taken to attempt to reduce the Likelihood of an accident and to ensure that omergency response plans and procedures are fully implemented while these plants operate.
Lesson Eight: The State of New York should press Congress to raise or entirely remove federal limits on ,
the financial liability of nuclear power plant owners / operators and designers / suppliers who may be at fault in a nuclear accident.
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/ ,1 II. The Chernobyl-4 Accident The Chernobyl Unit'4 nuclear power plant accident began at 1:23 a.m. on April 26, 1986, with a chemical explosion at the plant. 2j The cause of this explosion is currently unknown. 3f ,
An International Atomic Energy Agency' (IAEA) repert, which was
'1 based on interviews with Soviet ofNicthis, indica' ties that the reactor was being shut down'for planned maintenance at the time of the accident, with its core generating about; 6-7 percent of full power. 4/
r The explosion (or its aftermath) evId9 ntly resul ed in a reduction or loss of coolant flow to the reactor core. 'Despite the low power level' the inventory of fission products produced sufficient decay heat, that the coolant loss, coup, led with insufficient, unavaltiole, or untimely emergen::y cooling, led to severe core damage and ignition of the egraph'ite moderator. Sj 2f Themis Speis and Brian Sheron (NRC), " Status, Briefing on the Chernobyl Nuclear Accident: Presentation to. the ' Commission,"
May 13, 1986. '
3f There are a number of possible causes for such an explosion, .
but the precise cause is unknown. I6 is also currently unknown whether there was a single explosions, or multiple explosions, and, if the latter, their relative timing. It has been suggested, for example, that the accident was started by an explosion and subsequent fire in the turbine / auxiliary complex, resulting .in the production of hyd rogen which ' then escaped to the reactor building above
- the refueling deck and caused the explosion which destroyed the upper partrof the reactor build ing . This hypo thes is ,
however, cannot be confirmed or negated on the basis of the information currently available. ,
4j New York Times, May 10, 1986, text of statement on the Chernobyl accident released on May 9 by the IAEA
,5/ New York Times, " Consensus of Experts: The Accident Isn't over," May 10, 1986. -
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The Chernobyl-4 containment boundary failed in an as-yet unspecified manner, leading to the release of fission and other radioactive products to the environment.
European nations have reported elevated levels of many dif fe rent radioisotopes in air, water, and soil samples. 6_/ As of this writing, it is not clear to what extent fuel melted , 7/
although the quantitiles and types of radionuclides reported in Europe suggest very significant core damage and fuel melting. 8/
The first releases of radioactivity began the morning of April 26, 1986. Soviet officials stated that they began evauations in the af ternoon of April 27, approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> 6_/ U.S. Nuclear Regulatory Commission, " Request for Collection of Licensee Radioactivity Measurements ' Attributed to the Chernobyl Nuclear Plant Accident," IE Information Notice No. 86-32, May 2, 1986. Reported isotopes collected in Europe include Iodine-131, Cesium-134 and -137, Tellurium-132, Ruthenium-103, Molybdenum-99, Neptunium-239, and Niobium-95.
Some of these fission products had previously been predicted to remain la rgely in the damaged reactor core, even after fuel melting and containment failure.
-7/ The NRC has concluded that decay heat plus the heat f rom the graphite fire produced temperatures sufficient to melt the fuel. In addition, the NRC has concluded that "some or all of molten core material is probably on the reactor cavity -
floor" --
i.e., some of~ the core material may have melted out of the core region entirely. See, Themis Speis and Brian Sheron (NRC), " Status Briefing on the Chernobyl Nuclear Accident: Presentation to the Commission," May 13, 1986.
~8/ Preliminary dose estimates prepared by Lawrence Livermore National Laboratory assumed the release of half of the core inventory of Iodine-131 and Cesium-137, with most of this release occuring in the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (Lawrence Livermore National Laboratory, " ARAC Preliminary Dose Estimates for Chernobyl Reactor Accident," May 7, 1986, p. 2) . Such a magnitude of release, combined with detection of many different radioactive species in Europe, are consistent with WASH-1400 (U.S. Nuclear Regulatory Commission, Reactor .
Safety Study, October 197 5) radiation release estimates for core melt accidents.
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~g later. 9_/ On April 28, Swedish technicians at the Forsmark nuclear power plant discovered unusually high radiation levels on workers' clothing, and, finding nothing wrong with their own plant, demanded an explanation from the Soviet Union. 10/ For hours, none was forthcoming. Finally, late in the evening of April 27, the Soviets admitted that an accident had taken place at the Chernobyl plant, some 800 miles southeast of the Forsmark site. ll/
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9f Los Angeles Times, " Soviets Cite Local Officials' Mis]udgment," May 7, 1986.
,. l_0/ Time, " Deadly Meltdown," May 12, 1986. .
__11/ Newsweek, "The Chernobyl Syndrome," May 12, 1986.
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I III. Reactor Design Issues Chernobyl Unit 4 is a graphite-moderated, boiling-water-cooled, vertical pressure-tube nuclear power plant with an electrical output of 1,000 megawatts. 12/ The reactor is designated as an RBMK-1000 design. As of early 1986, there were fourteen RBMK-1000 plants in operation in the Soviet Union (including Chernobyl-4). The RBMK-1000 design, based on early Soviet plutonium production reactors, was completed in 1969, and the first unit went critical in 1973 (Leningrad Unit 1).
The low-enriched, uranium oxide fuel (approximately 192 metric tons) is contained in a large number (more than 1,000) of zirconium-niobium alloy pressure tubes embedded in a matrix of graphite blocks. Each pressure tube contains eighteen fuel rods and a central support member. The fuel rods are clad in a zirconium-niobium alloy. There are two stacked fuel assemblies in each fuel channel. On-line refueling is accomplished via a 12/ In forma tion in this section has been extracted and summa rized from the following references: N. A. Dollezhal, I. Y. Emelyanov, et al., "Some Features of Nuclear Power -
Plants With RBMK-1000 Reactors and Experience in Their Operation," IAEA-CN-42/385, September 1982; E. V. Kulikov,
" State-of-the-Art and Development Prospects for Nuclear Power Stations Containing RBMK Reactors," translated from Atomnaya Energiya, Vol. 56, No. 6, June 1984; Walter Mitchell, III, Design Features of the Soviet RBMK-1000/Chernobyl-4 Reactor, report prepared for the U.S.
Nuclear Regulatory Commission's Advisory Committee on Reactor Safeguards, May 4, 1986; B. A. Semenov, " Nuclear power in the Soviet Union," IAEA Bulle ti n , Vol. 25, No. 2; Themis Speis and Brian Sheron (NRC), " Status Briefing on the Chernobyl Nuclear Accident Presented to the Advisory Committee on Reactor Safeguards," May 8, 1986, and " Status Br.efing on the Chernobyl Nuclear Accident: Presentation to the Commission," May 13, 1986; and N. A. Dollezhal, -
" Graphite-water steam-generating reac tor in the USSR,"
Nuclear Energy, Vol. 20, No. 5, Oc tober 19 81.
special refueling machine located on the refueling deck above the reactor.
The reactor core region is a cylinder about forty feet in diameter and twenty-six feet high, and is contained in a reactor vault. The reactor vault is a steel-lined, prestressed concrete region below the refueling deck. The atmosphere in the reactor vault is inerted. The vault is designed for a pressure of 27 psi (0.18 MPa).
In contrast to numerous early press reports, the safety systems available at the Chernobyl-4 plant to respond to accidents are broadly comparable to those used in U.S. nuclear power plants. M/ Safety systems provided in the Chernobyl-4 design include passive coolant injection tanks (referred to in U.S. plants as accumulators or core flood tanks), as well as high- and low-pressure injections systems, which can be supplied with emergency power from three diesel generators (these diesels serve a two-unit station) . M/
The Chernobyl-4 design incorporates elements of both containment and confinement., There are two "drywell" regions -
which consist of the reactor vault and the prima ry enclosure which encompasses the primary coolant piping and main coolant pumps (the pump enclosure area is designed to a pressure of 56
'--13/ Compare, for example, descriptions in Themis Speis and Brian Sheron, op. cit., and Walter Mitchell, III, op. cit., with Final Safety Analysis Report (FSAR) listings of safety equipment for U.S. boiling water reactors, including i
Shoreham, Fitzpatrick, and Nine Mile Point Units 1 and 2.
See, also, New York Times, "Chernobyl Design Found to Include New Safety Plans," May 19, 1986. -
14/ Themis Speis and Brian Sheron, op. cit.
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psi) . Below these drywell areas is a two-layer suppression pool.
15/ The suppression pool is intended to condense steam and thereby reduce pressure in the drywell region. In addition, the suppression pool water is circulated through a heat exchanger, and then pumped through spray nozzles back to the suppression pool. lj The drywell areas are connected to the suppression pool via a system of valves and "downcomer" pipes. The remainder of the reactor building is a confinement structure. See Figure 1.
In principle, this arrangement is not dramatically dif ferent from U.S. boiling water reactors, particularly those of the so-called " Mark II" design (such as Shoreham or Nine Mile Point Unit
- 2) . The degree to which the comparison is accurate depends on design details of the Chernobyl-4 plant which are not yet publicly available. M/
---15/ Drawings contained in NRC documents appear to indicate the presence of a spray (" sprinkler") system in the air space above the two suppression pools. Such a system would assist in the suppression of steam and help hold containment pressure down. The source of the spray water and the system -
which supplies the spray water are not indicated in the NRC documents. See, Themis Speis and Brian Sheron (NRC),
" Status Briefing on the Chernobyl Nuclear Accident:
Presentation to the Commission," May 13, 1986.
l.6/ L. I. Turetskii, et al., "A System for Localising Failures of Generating Units with the RBMK-1000 Reactor," Thermal Engineering, Vol. 31, No. 2, 1984, pp. 117-118.
M/ The information most important to such comparisons includes the volumes enclosed by the drywell areas and the suppression pool, the amount of water in the suppression pool, the size of the downcomers, the design pressure of the d rywe ll and suppression pool areas, and a host of other details. Such information should become available over the -
next few months as the Soviet investigation into the Chernobyl accident proceeds.
The containment concept employed at Chernobyl-4 is referred to as a " pressure suppression" containment. Chernobyl-4 utilizes two water-filled pools (called suppression pools) to condense steam released into the containment during an accident. Pressure suppression containments are used in most boiling water reactors in the U.S. 18/ In addition, some pressurized water reactors ,
employ a pressure suppression concept re f e rred to as an " ice condenser" containment, which employs large volumes of ice to condense steam, rather than the pools of water used in most boiling water reactors in the U.S.
In comparison with large dry con tainmen ts used in most pressurized water reactors (such as Indian Point and Ginna), the pressure suppression containments are relatively small in volume.
Concerns have been raised for many years about the ability of pressure suppression containments to withstand the forces exerted by a core melt accident. Even the most recent studies suggest that such containments are predicted to fail very early in a range of severe accident scenarios. M/ At Chernobyl, 18/
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It is obvious from drawings and photographs of the Chernobyl plant tha t the plant does not have the " containment dome" that is characteristic of some boiling water and most pressurized water reactors in the U.S. It should be pointed
' out, however, that BWR Mark I and Mark II plants also do not have a " containment dome." One should not, therefore, necessarily as socia te the concent of containment with the
, presence or absence of a " dome."
M/ This is particularly true for Mark I boiling water containments and ice condenser pressurized water reactor containments, but is also true of Mark II containments as well. See, for example, NUREG-1079, Estimates of Early Containment Loads from Core Melt Accidents, draft report for comment, U.S. Nuclear Regulatory Commission, December 1985; -
and Steven C. Sholly and Gordon Thompson, Union of Concerned Scientists, The Source Term Debate, January 1986.
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preliminary reports suggest tha t the analogous containment system
, failed very early in the accident, although the precise mode of containment failure at Chernobyl is not currently clear. M/
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-20/ It has been suggested that the Chernobyl-4 containment could have failed from a number of causes, including an excess-reactivity explosion in the reactor core (see, Victor Gilinsky, "How Can We Learn More?", The Washington Post National Weekly Edition, June 2, 1986, "an uncontrolled chain reaction") a hydrogen explosion in the reactor vault
- (although the inerted atmosphere in the reactor vault should have prevented this), leakage past seals damaged by high temperature, radiation exposure, and/or high pressure, and by puncturing by the overhead crane when the crane lost structural supports in an explosion above the refueling deck. Any or none of these possible causes could have been involved. A final determination of the cause of containment failure awaits the release of additional information during -
the course of the Soviet investigation into the Chernobyl accident.
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IV. Sequence of Events (Accident Scenario)
The exact cause of the Chernobyl-4 accident is not known at
, this time. Several hypotheses have been advanced, however, which deserve mention. Former NRC Chairman Joseph Hendrie, 2_1_/ Harold .
Denton (Director of the Office of Nuclear Reactor Regulation at the NRC), and Canadian and Swedish nuclear officials have speculated that Chernobyl may have experienced a " station blackout" -- loss of all normal and emergency AC power. M/
One possible cause of station blackout is a fire, and it has been suggested that Chernobyl may have experienced a fire that burned through electric power cables to safety systems. M/
Regardless of plant design, electric power and cables are vital to reactor shutdown, provision of emergency coolant, and instrumentation to monitor an accident or determine its potential severity. The sufficiency of fire protection requirements for U.S. reactors has long been debated. Fires represent a so-called
" common mode" or " domino" failure that can simultaneously disable what would normally be considered to be redundant safety systems.
Other possible causes fo'r the accident have been suggested.
One potential cause that has been advanced is a " reactivity
- ~~21/ New York Timesy " Experts See Soviet Nuclear Accident As Being Long-Feared ' Worst Case'," May 9, 1986.
22/ Inside N.R.C., " Opinions Vary on Impact of Chernobyl Accident on U.S. Plants," Vol. 8, No. 10, May 12, 1986.
_2_3f New York Times, " Experts See Soviet Nuclear Accident As Being Long-Feared ' Worst Case'," May 9, 1986. See, also, -
Inside N.R.C., " Opinions Vary on Impact of Chernobyl Accident on U.S. Plants," Vol. 8, No. 10, May 12, 1986.
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transient" -- a sudden surge in reac to r power. 24/ Other possible causes for the accident that have been discussed are a fuel handling accident, a loss of coolant accident, M/ or a flow blockage to part of the core. M/
Soviet nuclear officials have repeatedly stated that " human error" was involved in the accident, and that there is no evidence of any basic design deficiency in the reactor. E/
While this is a somewhat predictable response, given the number of similar plants in operation and under construction in the Soviet Union, it may also be true. Human errors can increase the likelihood of accidents in any reactor (human error was at least partially to blame for the 1979 accident at Three Mile Island and the 1957 accident at the Windscale reactor in England), or amplify the, consequences of an accident. For. example, on several
- occasions, containments in U.S. commercial nuclear plants have been inadvertently left open for extended periods of time, offering a direct release pathway to the environment in the event 24/ Victoc Gilinsky, "How Can We Learn More?", The Washington Post National Weekly Edition, June 2, 1986; article mentions -
"an uncontrolled chain reaction."
25/ One of the designers of the Chernobyl plant (Ivan Emelyanov) suggested in an interview tha t one of the hundreds of cooling pipes burst, which may have triggered the accident.
He also suggested that a power surge from 6% to 50% of full I
power occurred in less than ten seconds after the coolant pipe failure. See, San Jose Mercury News, "Chernobyl Designer Blames Disaster on Human Error," May 20, 1986.
M/ Themis Speis and Brian Sheron (NRC), " Status Briefing on the Chernobyl Nuclear Accident Presented to the Advisory Committee on Reactor Safeguards," May 8, 1986.
27/ Los Angeles Times, " Human Error Blamed for Soviet Disaster," .
May 20, 1986; San Jose Mercury News, "Chernobyl Designer Blames Disaster on Human Error," May 20, 1986.
ot an accident. 28/ Such a containment "
bypass" failure would
, defeat even the strongest of U.S. containments, and result, in the event of a core melt accident, in a large release of e
radioactivity to the environment.
r 2_8/ Pacific Northwest Laboratory, Reliability Analysis of .
Containment Isola tion Systems, NUREG/CR-4220, prepared for the U.S. Nuclear Regulatory Commission, June 1985.
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V. Accident Consecuences Whatever the cause of the Chernobyl-4 accident, there is
, little question that a severe accident involving major fuel.
melting and early loss of containment is possible at U.S. _
reactors. The scientific community has mainly differed over the likelihood of such an accident and the size the resulting radioactivity release. The Chernobyl accident appears to negate the claims of both Soviet and American nuclear industry representatives that the likelihood of a large radioactive release was as low as one chance in a million per reactor year.
The Chernobyl accident demons tra tes both that such an accident is possible, and that its results can be devastating.
The magnitude of radioactivity released as,a result of a reactor accident, and the consequences of such an accident, have been the subject of numerous safety studies since the start of commercial nuclear power: the WASH-740 report in 1957, the abortive Brookhaven National Laboratory update of WASH-740 in 1965, the WASH-1400 report ("Rasmussen Report") in 1975, and more recent studies by Sandia National Ldboratories for the NRC. Generally, these studies indicate tha t , for U.S. re ac to rs , fuel melting d
, coupled with early containment failure could leave hundreds of square miles uninhabitable, necessitate decontamination or abandonment of thousands of square miles of land, and result in tens of billions of dollars in property losses and cleanup. costs.
The re is no questioning the need for the most stringent nuclear safety laws, as well as the need for rigid enforcement of -
those laws. But however well-designed, built, and operated, the 9
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chance of a serious nuclear accident at existing plants cannot be
, reduced to zero. All current nuclear plants can experience catastrophic failures. The consequences of such an event can i
involve huge land areas and the health and li f elihood of many
.. thousands of private citizens.
Twenty-three deaths have been attributed to the Chernobyl accident, 29/ although the number could rise substantially in the next few months. In addition, up to three hundred radia tion-related injuries have been reported, with eighty of those patients reported to be "in extreme danger." 0,/ A wide variation in the number of early deaths are possible for a radiolgical release of the magnitude which occurred at Che .Tobyl-
- 4. The ma'gnitude of the effects would deperid on the timing of the relsase, the elevation of the release point, the population distribution around the reactor site, the protective measures taken offsite and their timing relative to the time of the release, and the weather at the time of and subsequent to the release, among other factors. Thus, the size of the death toll in the Chernobyl-4 accident to da te cannot be taken to represent -
an upper limit on the possible casualties. Under less favorable weather conditions, early fatalities and injuries could have been much greater. 31_/
29/ New York Times, "Chernobyl Disaster's Toll Rises to 23," May 30, 1986.
3_0/ Ibid.
31/ Reactor accident scenario studies to date indicate tha t larget numbers of early deaths and injuries (numbers greater -
than a few hundred) would result from weather involving rain .
downwind from the accident site and/or a slowdown in wind
_ . - . _ _ _ . . , . - . . _ _ _ , , . . _ , , . , - . .-. . _ . -,_m , _
l Early radiation-caused deaths and injuries occur only at the
, very highest levels of exposure. Early fatalities would not be expected to occur at doses less than 150-200 Rems, and early a
injuries would not be expected to occur at doses less than 25-50 Rems. Such dose levels would generally be obtained only very near the plant or in areas heavily contaminated due to weather following the release (e.g., in the event of rain, which would tend to " washout" the radioactivity from the plume).
In contrast, results of accident studies indicate clearly that the long-term health effects and environmental impacts dominate the societal impact of a serious reactor accident.
32/
For example, the number of cancer deaths resulting from an accident with a large release of radioactivity to the environmental is predicted to reach into the thousands to several tens of thousands. 3_3/ Such cancers arise from the exposure of velocity, both of which would allow a large amount of radioactivity to deposit out of the plume onto the ground, thus exposing even sheltered persons to very high radiation doses. Such weather scenarios and resulting impacts are not limited to areas within ten miles of nuclear power plants, but could occur at distances of approximately fifteen to fifty miles. In comparison, the current planning basis -
distance under NRC regulations is a ten-mile diameter zone around the reactor site. See, Sandia National Laboratories, Technical Guidance for Siting Criteria Development, NUREG/CR-2239, prepared for the U.S. Nuclear Regula tory
, Commission, December 1982, p. 2-52.
32/ See, for example, Richard B. Hubbard and Gregory C. Minor,
, eds., The Risks of Nuclear Power Reactors: A Review of the NRC Reactor Safety Study WASH-1400 (NUREG-75/014), Union of Concerned Scientists (Cambridge, Mas sachuse tts) , August
. 1977.
3_3/ Similar numbers of non-fatal cancers would also be expected to occur; accident consequence models such as the NRC's "CRAC-2" code calculate only cancer fatalities, ignoring the -
fact that not a ll cancer victims die as a result of the disease.
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a large population to doses smaller than those which would pose
, an immediate health risk.
In addition to health effects, contamination arising from a serious accident poses significant societal problems. Land
- interdiction and agricultural restrictions in the event of a e .
large release of radioactivity could be necessary to distances ranging from twenty to more than fifty miles downwind, thereby involving areas in the hundreds to thousands of square miles.
M/ In the case of Chernobyl, potentially contaminated foods t
were removed from market and destroyed as far away as Italy. The European Economic Community nations barred Eastern European and Soviet foodstuffs produced within 625 miles of Chernobyl. M/
Livestock within twelve miles of the plant were siaughtered.
3_6,/
It is unclear at this time how long food supplies may be impaired due to the Chernobyl accident. There are no clear international agreements that distinguish between safe and unsafe contamination levels in food or water, nor are there procedures in place for the level of sampling needed to reliably make such determinations. Moreover, ,it must be recognized that some -
34/ D. C. Ald rich , et al., Technical Guidance for Siting Criteria DevelooEent, Sandia National Laboratories,
- j. , NUREG/CR-2239, prepared for the U.S. Nuclear Regula to ry Commission, December 1982, p. 2-62 and CRAC-2 computer model printouts, available at the NRC Public Document Room,
, Washington, D.C.
-35/ New York Times, " Europeans Squabbling Over Food: Is Their
, Produce Free of Radiation?," May 10, 1986; " Europeans Bar Food From the Soviet Bloc Until the End of May," May 13, 1986.
36 Themis Speis and Brian Sheron (NRC), " Status Briefing on the -
Chernobyl Nuclear Accident Presented to the Advisory Committee on Reactor Safeguards," May 8, 1986.
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radioactive materials are biologically concentrated by both
. plants and animals, potentially over periods of decades in the case of long-lived radioactive materials.
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i VI. Emergency Planning Issues The principal reason for a nuclear emergency plan is to '
, reduce the health consequences of any radioactive release. A.
secondary objective of emergency plans is -to mitigate the .
- , environmental damage which might be caused by a reactor accident.
For the mo,st part, U.S. nuclear emergency plans have been based on the assumptions that accidents would require evacuation or other protective actions out to a maximum of ten miles and that nearly all impacts would be contained within fif ty miles.
H/ The Chernobyl accident shows that the potential dimension of a serious nuclear accident can be substantially greater.
For example, Lawrence Livermore National Laboratory calculations suggest that iodine doses to the thyroid which would have required protective action under U.S. Environmental
[ Protection Agency standards H/ may have occurred over an area of i
E/ Officially, these are the planning distances for emergency l response --
"The choice of the size of the Emergency l Planning Zones represents a judgment on the extent of -
detailed planning whicti must be performed to assure an adequate response." See, NUREG-0654, Criteria for Preparation and Evaluation of Radiological Emergency Response Plans and Preparedness in Support of Nuclear Power i '
Plants, U.S. Nuclear Regulatory Commission and Federal l Emergency Management Agency, Rev. 1, November 1980. The NRC, in adopting its emergency planning rules in 1980,
- effectively took the position that the ten- and fifty-mile planning zones provided an adequate basis for response at greater distances. -
38/ The U.S. Environmental Protection Agency specifies
" Protective Ac tion Guides" or PAGs of five to twenty-five Rem to the thyroid.. from inhalation of radioactive iodine.
U.S. Environmental Protection Agency, Manual of Protective -
Action Guides and Protective Actions for Nuclear Incidents, EPA-520/1-75-001, September 1975, Revised June 1980.
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thousands of square miles. H/ In addition, potassium iodide tablets were distributed throughout Eastern and Western Europe, and vegetables and dairy products were withheld from market because of actual or suspected contamination. It is highly unlikely that any European nation had an emergency plan to address such widespread radiologic hazards, or that the Soviets had any plan to notify adjoining nations. It seems unlikely that emergency plans in the U.S., being limited to a 50-mile radius around the reactor site for ingestion exposure planning, would be capable of dealing effectively with an accident of Chernobyl's magnitude. -
The long term health impact of the Chernobyl disaster cannot be predicted accurately at this time. Whatever the toll, some impac ts could have been reduced with prompt notification of affected governments. Che rnobyl clearly demonstrates the need for prompt and ef fective notification about nuclear accidents to provide ample time for state and local authorities to act to mitigate the consequences of the accident. It also demonstrates the need to expand the radiu.s of concern compared with current -
NRC planning standards.
In addition, the Ch e rnobyl accident raises a number of emergency planning issues which need to be addressed by the State 39/
- Lawrence Livermore National Laboratory, " ARAC Preliminary Dose Estimates for Chernobyl Reactor Accident," May 7, 1986.
A generic study by Sandia Na.tional Laboratories indicates that for an arbitrary large release, the EPA PAG doses for the thyroid pathway could be exceeded to distances of hundreds of miles. See, NUREG/CR-2239, Technical Guidance for Siting Criteria Development, Sandia National -
Laboratories, prepared for th e U.S. Nuclear Regulatory Commission, December 1982, p. 2-61.
Q , - .
of New York. First, nuclear power plant emergency plans should
, explicitly address the possibility of large accidents with impacts requiring protective measures beycod the current ten- and a
fifty-mile mile planning zones. In adopting the emergency planning rule specifying the ten-mile " plume exposure pathway" emergency planning zone, the NRC concluded that the planning within ten or fifty miles of a nuclear power plant site would provide an adequate base to expand response efforts beyond this area. While this may be true for some sites, it is probably not true for sites with higher than average population density, increasing population density (and numbers of special facilities such as schools, nursing homes, prisons, etc.)) just outside the ten-mile planning zone, or for sites with access / egress routes which are constrained by geographic features. Moreover, should emergency response be needed outside ten miles, it would likely be needed at distances considerably beyond ten or fifty miles, in which case the existing plans may have little relevance.
Thus, what seems to be needed is emergency planning on a regional basis. Both the early and long-term ef fects of a -
serious reactor accident could be mitigated (perhaps considerably so) by an ef fective regional emergency plan which provides for a range of protective measures, including the extension of the
. current planning zones. This conclusion implies, in the case of New York, the need to consider possible accidents at nuclear power plants in other states or at plants in Canada. This is particularly important because such accidents could necessitate emergency response in counties which may not now have
= l radiological emergency plans to deal with the accident and its
{
impacts.
As a practical matter, if a serious accident were to occur, people would inevitably evacuate beyond any radius selected by i s ta te or local officials or by the NRC, particularly after the i experiences with Three Mile Island and Chernobyl. Emergency plans should be designed to identify and, if possible, resolve such problems, but they cannot do so if they focus on too small an area.
A second obvious lesson of Chernobyl is tha t we should not build new nuclear power plants in urban areas that are essentially impossible to evacuate quickly. Urban siting severely limits or renders impossible the prompt evacuation of the near-site population (as distinct from relocation; the former implies movement before plume passage, whereas the latter implies movement after plume passage) . This inc reases the potential for large early casualty tolls in the event of a large release of radioactivity.
Urban siting also increases the societal impact of a serious -
accident. This is due to the greater social disruption occasioned by the need to re loca te the popula tion from a large urban area should it become necessary. Estimated property losses
, from reactor accidents at urban-sited plants are also considerably larger than for remote-sited plants.
3 Existing urban-sited plants, such as Indian Point, merit a special attention to containment adequacy. Improvements can be made to strengthen the ability of existing reactor containments
o r
, to withstand accidents and minimize releases. Such potential
- improvements include, for example, " filtered, vented containment" I
concepts which would trade off a release of noble gases such as krypton and xenon (which do not cause long-term contamination problems) against the more certain ability to contain the more hazardous radioactive particulates such as cesium, iodine, strontium etc.
For existing urban-sited plants which cannot be adequately improved in this respect, plans should be made for an orderly phase out of operations. In the interim, strengthened inspection enforcement neasures should be undertaken to attempt to reduce the likelihood of an accident and to ensure that emergency plans I ~
and procedures are always in place should an accident nonetheless occur.
Third, nuclear emergency plans tend to overemphasize evacuation planning per se at the expense of other forms of emergency response. The wide dispersion of radioactive material from the Chernobyl accident illustrates the need for effective tracking of radioactive plumes in the atmosphere, prompt --
identification of contaminated areas to assure that the popula tion in such areas can be promptly relocated, provision of uncontaminated food and water, in terdic tion of agricultural supplies, decontamination of affected land and water, and standards for reentry into contaminated areas. Again, this i
suggests the need for regional planning (and, in the case of Canadian pla n ts , international cooperation between the State of New York and Canadian authorities) .
- ~
Another element of emergency planning concerns the possible
. reluctance of reactor operators to notify numerous government authorities early in an accident when it is not clear that a
control of a reactor has been irretrievably lost. In addition, there have been problems with reliable communication of plant s ta tus and radiation monitoring information during previous accidents. The Soviets now claim that the operators at Chernobyl failed to appreciate the potential impact of this accident, and therefore kept even Moscow in the dark . 4_0_/ There was also a lack of accurate public information during the Three Mile Island accident. The operators of Three Mile Island repeatedly told the press (and the state government) that their plant was completely under control in the early stages of the accident, when, in fact, top of ficials of the NRC were extremely worried and the plant was not under control. 4J/
Faced with these problems, some state agencies have acquired the capacity to monitor on-site and o f f-si te radiation levels from remote - f acilities. While any such monitoring instruments can malfunction, off-site instrumentation under public -
supervision gives responsible state officials prompt notification of a problem (under most circumstances), and provides a more reliable basis for making informed decisions on ordering
- protective measures up to and including evacuation. This M/ New York Times, " Delay Reported on Evacuation at Nuclear Site," May 7, 1986.
41/ Special Inquiry Group (Mitchell Rogovin, Directo r) , Three Mile Is la nd : A Reoort to the Commissioners and to the Pub- -
lic, prepared for the U.S. Nuclear Regula to ry Commission, NUREG/CR-125 , Vols. I and II, 1980.
~
monitoring equipment includes a plant stack monitor and sixteen
. radially positioned gamma radiation monitors two miles from the reactor site.
Over the last four years, the State of Illinois has put in place a highly sophisticated nuclear emergency program.
Illinois' Department of Nuclear Safety in Sprir g field has a direct computer link to each reactor control room in the state.
The Department has developed computer software that facilitates interpretation of the monitored parameters to identify an evolving accident. This provides the Department with an early warning system that permits state officials to assess independently the possibility of a large release, dispa tch radiation monitoring teams and emergency response personnel, and no ti fy local officials of a possible evacuation. The Department also has a direct telephone link to each reactor control room.
Q/
i g The NRC's Region I Office recently wrote to all nuclear power plant owners in the Region about its possible plans to set up an " Emergency . Response Data System" (ERDS). To fulfill its ro le , NRC has determined that it needs reliable -
information concerning core and coolant conditions (to assess the extent or likelihood of core damage), containment conditions (to assess the likelihood of containment failure), radioactivity release rates (to assess the
, immediacy and degree of public danger), and meteorological data (to assess the distribution of potential or actual impacts of a radiation release on the public). The NRC
, letter states that experience with " voice-only communica tions" links has demons tra ted that excessive amounts of time are needed for data transmission, that error rates are high, initiation of data links has been slow, and that voice-only data links creates an excessive drain on a limited number of technical experts available to assess the situation. See, for example, an April 25, 1986, letter from Richard W. Starostecki (NRC) to Lo ng Island Lighting ,
Company,
Subject:
" Emergency Communication System, Point-of-Contact."
_ _ _ _ _ _ . ~ , . _ _ . - _..__.._.__.m - . - _ _ . _ . _ _ . . , - - , - - _
Applied locally or regionally, this type of system could
. resolve many of the prompt notification problems and inaccurate / untimely data transmission problems facing any state with an operating reactor. It would permit off-site authorities know almost as quickly as reactor operators when a reactor has a problem. Such connections to the regional NRC office and appropriate state of fices would permit qualified authorities to monitor the course of an accident, assess its potential severity, and plan precautionary measures. -
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e-1 If VII. Nuclear Accident Liability Limitations The Chernobyl accident also focuses attention on the nuclear
, accident liability issue. Currently, federal law limits the lia-bility of reactor operators in the event of a catastrophic acci- _
dent. This legislation -- called the Price-Anderson Act --
is now being considered for renewal by Congress. The current limits under the Price-Anderson Act are less than $1 billion. There is little question tha t this limits could be quickly reached if a Chernobyl-like accident occurred in the United States. At that point, the responsibility for treating or compensating accident victims for health or property damage would fall on the state or federal government, and reactor owners / operators and plant designers / constructors would be held harmless from further liability.
The widespread damage caused by the Chernobyl accident clearly indicates the need for a substantial increase in the level of nuclear accident insurance required of U.S. utilities.
A proposed revision of Price-Anderson would require automatic payments, in the event of an accident, from all U.S. utilities with operating nuclear plants. In addition to these insurance
, provisions, we see no reason tha t the public or a state government should be deprived of further recourse from guilty parties through litigation. That should be accomplished by raising significantly or removing entirely the current cap on nuclear liability.
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VIII. Conclusion Chernobyl demonstrates very clearly that nuclear power plant d
accidents are possible and that their consequences can be catas-trophic. Although the American nuclear industry initially ..
claimed that a Chernobyl-type accident could not happen here, recent reports indicate that Chernobyl-4 had safety systems tha t were analogous, at least in principle, to the safety features on some American commercial reactors, including Shoreham.
Even if the specific sequence of events at Chernobyl are eventually demonstrated to be very unlikely in U.S. reac to rs ,
there are a host of other types of accidents which can occur and result in potentially large radiological releases to the environment. Thus, any design differences that exist between Chernobyl Unit 4 and domestic reactors provide little basis fo r complacency.
As tragic as Chernobyl was, it would be even more tragic if we failed to learn the obvious lessons of this accident. We must <
redouble our efforts to . reduce the likelihood of nuclear accidents, and strengthen our emergency response procedures. To these ends, we must learn from the basic lessons of Chernobyl
, including:
. Lesson One: General design simila rities in terms of containment and safe ty systems exist between Chernobyl-4 and many U.S. nuclear power plants, particularly boiling water reactors. These simila rities should be considered in reassessing the vulnerablility of U.S.
nuclear power plants to serious accidents. The need
, for such a reassessment is particularly great for pressure suppression containments. This conclusion places a premium on the prompt and thorough-going examination of the Fitzpatrick, Nine Mile Point Units 1 and 2, and Shoreham nuclear plants.
Lesson Two: Catastrophic reactor accidents --
.resulting in very large releases of radioactivity --
are possible in U.S. reactors. Such accidents might be caused by inherent design deficiencies, lack of construction quality, human error, external events, sabotage, or multiple causes. New York State emergency planning efforts should explicitly consider such serious accidents.
Lesson Three: The long-term impacts of radiation releases on agriculture, health, water, and the economy are likely to be mo re disruptive to society than the _
short-term impacts. Unfortunately, current emergency plans place insufficient emphasis on long-term radiation safety measures. Both the early and long-
. term consequences of a serious reactor accident can be partially mitigated with an effective regional emergency plan which provides for a variety of protective measures, including an extension of the current ten- and fifty-mile emergency planning zones.
New York state should also consider the need for
, emergency response for accidents at nuclear power plants in other states and at plants in Canada, since 4
such accidents could require emergency response in counties which do not now have radiological emergency plans to deal with the accident.
Lesson Four: Emergency plans should be in place at all times for an operable reactor, regardless of . whether the plant is undergoing testing, temporarily out of service, or operating at full power. 41 /
~
Lesson Five: State governments and regional Nuclear Regulatory Commission (NRC) offices should have an automatic data link connecting them with nuclear power plant control room instruments to ensure prompt assessment of the severity of any potential nuclear power plant accident. Such a data link would help reduce the potential for miscommunication of essential _
plant status and radiation release inf o rma tion in time of crisis.
- 43/
-- Although Chernobyl-4 was at low power at the beginning of the accident, the plant achieved initial criticality on December 14, 1983 (Walter Mitchell, III, Design Features of the Soviet RBMK-1000/Chernobyl-4 Reactor, report prepared for the U.S. Nuclear Regulatory Commission's Advisory Committee on Reactor Safeguards, May 4, 1983), and had operated for some time at higher power levels. Thus, the plant had developed a large amount of fission products and, as a result, a considerable decay heat inventory at the time of the accident on April 26, 1986.
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Lesson Six: The State of New York should ensure tha t adequate regional and/or federal capabilities are in
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place for tracking radioactive plumes, and for coordinating actions "needed to interdict potentially contaminated food and water supplies, and decontaminate potentially large affected a'nd areas. I'
~-
Lesson Seven: Remote siting should be r'egilired for new nuclear power plants. Urban, siting severely limits or renders impossible ths prompt ' evacuation of the near-site population, which increases th e potential for large early casualty tolls ih the event of a serious accident. .Further, urban siting increases the potential for society disruption resulting from a serious nuclear accident since a larger number of people yould have to be relocat'ed, and a greater level of economic activity would be disrupted. Existing urban-sited plants, such as Indian Point, merit special _
review of containment adequacy. Improvements can be made to strengthen the ability of existing containments to withstand accidents and minimize releases. Plans should be developed for the orderly pliasc out of such plants which cannot be adequatel'/ Ilmproved in this regard. In the interim, strengthened . inspection and enforcement measures should be Taken to attempt to reduce the likelihood of an accident and to ensure that
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emergency response plans and procedures are fully
, implemented while these plants operate.
4 Lesson Eight: The State of New York should press Congress to raise or entirely remove federal limits on '
c the financial liability of nuclear power plant owners / operators and designers / suppliers who may be at fault in a nuclear accident.
8 3
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