ML20212M059
| ML20212M059 | |
| Person / Time | |
|---|---|
| Issue date: | 06/23/1986 |
| From: | Stello V NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | |
| Shared Package | |
| ML20212M028 | List: |
| References | |
| FOIA-86-602, TASK-PII, TASK-SE SECY-86-185, NUDOCS 8608250361 | |
| Download: ML20212M059 (46) | |
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i l POLICY ISSUE June 23,1986 SECY-86-185 For: The Comissioners -
From: Victor Stello, Jr.
Executive Director for Operations
Subject:
PROGRAM PLAN FOR CHERN0BYL ACCIDENT FOLLOWUP
Purpose:
To inform the Comission of the staff's plans for a task force and program to follow up on the facts and implications of the Chernobyl accident.
Sumary: The program consists of two phases. The first phase, to be done in collaboration with other agencies, is to ascertain the facts surrounding the Chernobyl accident, including plant characteristics, accident causes and consequences, and emergency measures. The second phase is to evaluate the implications of the facts found for U. S. nuclear regulatory policies and practices. Reports on the two phases are expected to be submitted in December 1986 and February 1987. Interim reports to the Comission are planned.
Dr. Themis P. Spets, Director of the Division of Safety Review and Oversight in NRR, will head the task force.
Background:
The plans described are responsive to Chairman Palladino's memorarMum, " Task Force Group to Monitor and Study the Chernobyl Accjdent," dated May 5, 1986.
The U. S. interagency task force established in the accident's imediate aftermath to monitor the potential environmental impact on the U. S. completed its efforts on May 14, 1986.
To support the interagency task force, the NRC established the Chernobyl Incident Tracking Team. This team is now winding down its efforts.
An initial coordination meeting with DOE, FEMA, and other agencies was held on June 13, 1986, to discuss comon and
Contact:
T. Speis, NRR 49-27517 8608230361 860022 PDR FOIA YAFFE86-602 PDR
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closely related Chernobyl work items. General agreement l was reached along the lines indicated in the enclosed program plan; discussions are in progress concerning <
detailed subdivision of work assignments, based on the '
appendix to the enclosed plan as a starting point. It was agreed that NRC will provide overall administrative coordination.
A mid-to-late August 1986 IAEA meeting is being arranged for the purpose of receiving a report by the Soviet Union on the causes and event sequence of the Chernobyl accident.
Discussion: Program Description A program plan is enclosed. Our ability to successfully execute this program will be sensitive to the extent and nature of the information that becomes available, and may i have to be adjusted in light of information developments as necessary.
The following are summary descriptions of the fact-finding and implications programs. More detailed descriptions are provided in the enclosure.
Fact-Finding Program The facts of interest are divided into three. general areas:
- 1) Plant Characteristics and Accident Causes, 2) Radiological Releases and Consequences, and 3) Emergency Preparedness and Response. The principal responsibility for evaluating the first area has been assigned to NRR. RES has been assigned responsibility to develop the facts concerning the radiological releases, and NRR has responsibility for developing the facts concerning the radiological consequences.
IE is assigned responsibility for evaluating the emergency preparedness and response area.
The Plant Characteristics and Accident Causes area includes fact finding concerning site characteristics, design of structures, primary system enclosure, nuclear and control systems, thermal-hydraulic features, refueling, safety systems, auxiliary systems, plant shielding, operations, quality assurance, operator training, loss of safe shutdown capability and the accident itself--its causes, scenario, and consequences. With respect to plant design and operations, the scope of information sought is intended to allow development of a sufficient understanding of the
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3 plant design and related aspects to ascertain the root causes of the accident and to evaluate it in terms of U. S.
reactor designs. A comprehensive understanding of the Chernobyl design (beyond the indicated scope) does not appear necessary.
The radiological release efforts will include consideration of plant features and conditions affecting accident and post-accident phenomenology and source terms. The radiological consequences aspects will seek information concerning meteorology, hydrology, air and liquid pathways, and individual and population doses. Dose-correlated medical treatment data on severely injured individuals and an epidemiological study of populations affected by lower levels of radiation are further needs in this area. However, they are not included in the current NRC program plan.
The emergency preparedness and response task will seek to ascertain facts concerning as to emergency plans and experience with actions actually taken, including evacuation, relocation, decontamination, and reentry.
Implications Evaluation The factual data from the fact-finding program will be evaluated for possible implications for the regulation of U. S. plants. The staff's initial judgment that no immediate ections on operating U. S. plants were warranted will be reviewed in the light of the more extensive factual information.
The work is intended to identify any needs for near-term Commission action as well as any areas requiring more detailed study as a basis for possible action. The implications to be considered will include those of similarities and differences in specific plant features.
Task Force An interoffice NRC task force has been formed to carry out the Chernobyl accident followup program. The Director of the task force, assigned on a full-time basis, is Dr. Themis P. Speis, Director of the Division of Safety Review and Oversight in NRR. Other senior staff members assigned to the task force and their principal areas of responsibility are as follows:
I L T. Speis/B. Sheron, NRR - Plant Characteristics and Accident Causes W. Morris, RES - Radioactive Material Releases.
F. Congel, NRR - Radiological Consequences E. Jordan, IE - Emergency Preparedness and Response Designees of other offices will be called upon for contributions as required. These will include IP AE00, Region I, ELD, and DEDR0GR.
The task force will carry out both phases of the program (fact finding and implications evaluation) and will coordinate the work of other contributing agencies in the fact-finding phase. IP will provide international coordination assistance.
A senior management oversight group has been formed to guide and oversee the task force's implications evaluation work. Its composition is as follows:
Harold R. Denton, Director, NRR Thomas Murley, Regional Administrator, Region I Clemens Heltemes, Director, AEOD James Taylor, Director, IE Denwood Ross, Deputy Director, RES Guy Cunningham, Executive Legal Director James Sniezek, Deputy Executive Director for Regional Operations & Generic Requirements James Shea, Director, IP The task force will keep the senior management oversight group advised of findings in the fact-finding phase, assist the oversight group in planning its work and help in possible identification of any urgent NRC action requirements.
Schedule Any interim findings that may indicate a need for urgent Commission action or are otherwise of unusual significance will be promptly brought to the Comission's attention.
Otherwise, the anticipated schedule is as follows:
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Mid-to-late August 1986: IAEA meeting to receive Soviet report Sept. 1986: IAEA report on August meeting Dec. 1986: Report on fact-finding phase Feb. 1987: NRC implications evaluation report To be scheduled (perhaps Sept. 1986 and Jan. 1987):
Interim Commission briefings To be scheduled: ACRS reviews Both the factual and implications reports may identify some areas requiring further work. (For example, followup of longer-term radiation consequences information as it develops may well be in order, as an extension of the work described under Task 3.2.3 in the enclosed program plan.)
Resources Approximately six staff-years of NRC effort is estimated to be required, a little over half of it in NRR and most of the rest in IE and RES. An additional professional effort of approximately four person-years will be required as contract support at a cost of about $600,000, coming mostly or entirely from national laboratories. About one-half of this contract effort will support NRR; the rest, RES and IE.
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, r ExecutiveDirect6f for Operation's
Enclosure:
NFf Program Plan for Determining (se Implications of the Chernobyl Accident on U. S. Nuclear Regulatory Policies and Practices l
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NRC PROGRAM PLAN FOR DETERMINING THE IMPLICATIONS OF THE CHERNOBYL ACCIDENT ON U. S. NUCLEAR REGULATORY POLICIES AND PRACTICES JUNE, 1986 3
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I Contents
- 1. Program Objective
- 2. Background
-3. Fact-Finding Program 3.1 Plant Characteristics and Accident Causes
,' 3.1.1 Site Characteristics .
3.1.2 Design of Structures 3.1.3 Nuclear and Control System Design 3.1.4 Thermal-Hydraulic Design 3.1.5 Reactor Enclosure Design
, 3.1.6 Safety Systems Design 3.1.7 Refueling
! 3.1.8 Auxiliary Systems 3.1.9 Design Basis and Beyond Design Basis Accidents
- 3.1.10 Loss of Capability to Achieve Safe Shutdown 3.1.11 Quality Assurance and Operator Training 3.1.12 Operations 3.1.13 Plant Shielding 3.1.14 The Chernobyl Accident 3.1.14.1 Causes 3.1.14.2 Scenarios 3.1.14.3 Consequences 3.2 Radiological Releases and Consequences l
l 3.2.1 Radioactive Materials Released
! 3.2.2 Dispersion of Radioactivity
( 3.2.7 1 Meteorological Conditions 3.2.2.2 Hydrology 3.2.3 Radiation Consequences 3.2.3.1 Individual Doses 3.2.3.2 Population Doses 3.3 Emergency Preparedness and Response 3.3.1 Emergency Plans 1
3.3.2 Experience with Protective Actions Taken 3.3.3 Decontamination, Relocation, and Reentry
Contents (Continued)
- 4. Coordination 4.1 Industry and Other U. S. Government Agency Efforts 4.2 International Efforts 4.2.1 IALA 4.2.2 CSNI 4.2.3 Other International Efforts
- 5. Implications Assessment Program Appendix: A Possible Inter-Agency Work Distribution for the Fact-Finding Program.
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- 1. Program Objective Upon learning about the Chernobyl accident in the Ukraine region of the U.S.S.R., the NRC established an incident tracking team. Using the available design information on the Chernobyl plant, and the reported information about the accident, the tracking team could not identify any aspects of the Chernobyl accident with a nexus to operating U. S. plants that warranted the NRC to require immediate corrective actions to these plants.
In order to either confirm this judgment or to determine what changes may need to be made to our regulatory programs and practices, including any changes to operating U. S. plants, it is necessary to ascertain the facts concerning not only the Chernobyl accident, but also the Chernobyl plant design. Once the facts are established to the best of our ability, only then can the implications of the Chernobyl accident be determined.
The objective of this plan is twofold. The first part sets forth the program which the NRC will follow to systematically determine the facts surrounding the Chernobyl accident and plant design--facts bearing on the cause, sequence and consequences of the accident. The second part sets forth the major elements of the program the NRC will follow to determine the implications of the Chernobyl accident on U. S. nuclear regulatory policies and practices. The fact-finding part of this program will involve substantial coordination with other U. S.
organizations and agencies and will be documented as a separate report. The implications portion of this program will address only those implications in l
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NRC's jurisdiction; in the preparation of this report participation by other agencies will be sought as related responsibilities warrant.
- 2. Background At approxtmately 1:23 a.m. on April 26, 1986, a serious accident occurred at Unit Number 4 of the Chernobyl Nuclear Station near the city of Kiev in the U.S.S.R.
The accident involved severe damage to the reactor and the structure that housed it. Significant radiological releases occurred as a consequence of the accident which were ultimately detected around the world. In the immediate aftermath of the accident, the U. S. Government established an interagency task force to assess and monitor the accident in order to determine its potential environmental impact on the United States. This interagency task force effort was completed on May 14, 1986.
l To support the interagency task force, the NRC established the Chernobyl Incident Tracking Team. This team is now winding down its efforts and completing preparation of a draft report of its efforts.
We still do not have much information regarding the design of the plant, nor do we have any hard information on the cause(s) of the accident. Because of this, implications of this accident on U. S. regulatory practices (e.g., source term implications) and policies cannot yet be determined.
3 In order to evaluate the implications of the Chernobyl accident on U. S.
regulatory policies and practices, it is first necessary to ascertain the facts associated with the accident. The first part of this plan describes the details of the fact-finding effort. The second part of the plan describes how the implications for U. S. plants will be developed.
- 3. Fact-Finding Program The major regulatory concerns that arise from Chernobyl can be divided into three general areas. These are 1) Plant Characteristics and Accident Causes,
- 2) Radiological Releases and Consequences, and 3) Emergency Preparedness and Response. Therefore, it is in these three areas that the NRC's fact-finding efforts will concentrate. Each of these areas is discussed in more detail in the following sections. Because these areas are distinct, they also lend themselves to be evaluated by specific offices in the NRC. I have assigned the evaluation of the plant characteristics and accident causes and consequences to the Division of Safety Review and Oversight in NRR. The Division of Reactor System Safety in RES is assigned to evaluate the Chernobyl source term. The Division of Emergency Preparedness and Engineering Response in IE has been assigned to determine the facts associated with evacuation and emergency planning at Chernobyl. Finally, the Division of Safety Review and Oversight has been designated as the lead organization to coordinate and integrate this
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3.1 Plant Characteristics and Accident Causes i
The following sections identify those aspects of the Chernobyl design that could have contributed to or influenced the course of the accident. The scope
- of information sought here is intended to develop a sufficient understanding of the plant design and related aspects to understand the accident event and to evaluate it in terms of U.S. reactor designs.
3.1.1 Site Characteristics To the extent possible, an understanding of the Chernobyl site characteristics will be determined. This will include site geography, hydrology, meteorology, geology, seismology and demographics. This information will allow the staff to understand how the consequences of the Chernobyl accident were influenced by the site characteristics. It will also allow a comparison of similarities to 3 and differences from U. S. sites to be made.
1 i 3.1.2 Design of Structures i
j The purpose of this effort is to develop an understanding of the approach used for Chernobyl in the design of structures, components, equipment and systems to accommodate dynamic accident, seismic, wind, tornado and flood loads. Of particular interest here is the containment / confinement / suppression pool structures and building foundations. This information will allow the staff to assess the response of the plant to the loads generated by the accident.
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3.1.3 Nuclear and Control System Design The nuclear and cor: trol system design appears to have played an important role in the Chernobyl accident. Therefore, this effort should be given considerable emphasis. A good understanding of the mechanical design of the reactor (including the materials of construction) and the neutronics and thermal-hydraulic characteristics of the Chernobyl plant needs to be developed.
Similarly, there is a need to understand the physics of the design (i.e., the various reactivity coefficients and effects) and its dynaraic behavior under operational and abnormal transients. An understanding of the trip design and philosophy will be developed.
The xenon transient characteristics of Chernobyl and the interplay between the various control mechanisms employed in the plant will be investigated.
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The study will attempt to provide an understanding of the control of power and temperature distributions and will, therefore, interface closely with efforts to understand the thermal-hydraulics characteristics of the plant. The study will also attempt to provide an understanding of plant control during refueling conditions.
3.1.4 Thermal-Hydraulic Design The purpose of this effort is to develop a good understanding of the fluid flow, heat transfer and heat removal characteristics of this pressure tube
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reactor design. This will include the basis for flow regulation, steam l l
production, pressure control and relief. An understanding of the components and systems involved in this process, as well as their operation and control, is needed. The design basis for thermal-hydraulic systems will also be investigated.
3.1.5 Reactor Enclosure Design One of the major questions that has been raised about Chernobyl is whether or not the structures surrounding the reactor and primary system could be considered the equivalent of a containment structure that surrounds plants in the U. S. This task will involve gathering all of the information available on the enclosure design and evaluating the degree of containment or confinement it provides. This is a critical element in the comparison of accident consequences at Chernobyl to those that can be postulated for U.'S. plants.
3.1.6 Safety Systems (ECCS, Suppression Pools, Sprays, Etc.) Design An understanding of the design and operation of the major safety related systems must be developed. This will include design (and design bases) and operation of the suppression pool, ECC and spray systems. In particular, the nature and spectrum of accidents these systems are designed to handle will be investigated.
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i 3.1.7 Refueling i 4
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There is currently some speculation that the accident at the Chernobyl plant
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may have been caused by an error involving a refueling operation. Moreover, t
because the Chernobyl plant was capable of on-line refueling (refueling with :
the reactor at power), the concept of primary system and containment integrity i during power operation needs to be examined. This task will investigate the
! procedures and methods used in conducting refueling of the Chernobyl unit.
I 3.1.8 Auxiliary Systems (Water Cleanup. Offgas. Spent Fuel, Radwaste) l 4
This program will investigate the design and design bases for the various auxiliary water, gas and radwaste systems. This will also include the design
, of the spent fuel storage and processing systems. Refueling itself is a i separate task.
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! 3.1.9 Design Basis And Beyond The Design Basis Accidents 4
This effort will attempt to develop an understanding of the types of transient conditions (both operational and abnomal) for which the plant is designed.
The study will review the extent to which accidents beyond the design basis
- (e.g., severe or core melt accidents) are accomodated in U.S.S.R. RBMK-1000 l designs. It would be of interest to detemine what accidents were and were not considered in the plant's safety analysis.
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8 3.1.10 Loss of Capability to Achieve Safety Shutdown The possibility that electric power to vital safety and control systems was lost due to fire or explosion early in the accident will be evaluated. The task will try to obtain information on the initiating events and their location; the degree of separation of redundant safety systems, routing of control and power cables and associated circuits, alternate shutdown arrangements and alternative power supply sources. (This topic relates to the implementation of numerous features of safety and control system design).
3.1.11 Quality Assurance and Operator Training One conclusion of the TMI-2 accident was the inappropriate operator reaction to a simple mechanical failure. This was ultimately attributed to management failures and lack of appropriate training of the operators. Human error has been mentioned by the USSR as a part of the initiating event (as it was also at Windscale). This task will seek to obtain information on the training and operating procedures in use at Chernobyl, especially those related to emergencies and unusual events. Information as to the availability of simulators will be sought.
3.1.12 Operations To the extent possible, the general philosophy of operations including operating staff levels and types, on-shift maintenance activities, shift
9 supervisor, administrative controls on out-of-service equipment, etc., will be investigated.
3.1.13 Plant Shielding The plant shielding design and practices will be investigated to determine protection offered to plant staff and sensitive equipment during operations and its impact on accessibility to plant areas during and after an incident.
3.1.14 The Chernobyl Accident 3.1.14.1 Causes This effort will describe the cause or causes of the accident, drawing on the above-described tasks, and will attempt to develop further insights into these
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Causes.
3.1.14.2 Scenarios This work is intended to describe the evolution of the accident, including any compounding failures which contributed to its subsequent evolution and/or severity, including any human errors involved.
3.1.14.3 Consequences This task will draw together information developed through other tasks concerning the consequences of the accident.
10 3.2 Radiological Releases and Consequences
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The following subsections identify information that should be obtained in order to understand source terms, release pathways, and accident consequences that resulted from the Chernobyl accident. It may be possible using severe accident analytical methods to bridge some of the gaps in available information and infer some of the basic conditions of the accident to supplement this information.
3.2.1 Radioactive Materials Releaseo There are two bases for making estimates of the radioactive materials released (source term). One uses an estimate of the inventory of radionuclides available in the reactor, a guess at to the scenario, and an understanding of the potential release from the core and confinement structure. The other uses qualified data of amounts and timing of radionuclide detection downwind and an estimate of the meteorological conditions between the reactor and the detection site for the critical time period. The first of these source terms can be considered a forward estimate and the second, a backward estimate. Comparison of the two estimates at the end of the fact-finding period can shed light on the quality of either estimate.
For the forward estimate, information that will be sought includes: (1) power level, flux spectrum and distribution, and operating history to calculate the l
11 inventory (this calculation is in progress at Los Alamos); (2) a scoping thermal analysis based on information from the scenario, including the effect of a reactivity insertion transient, hydrogen burn, or graphite burn to provide release information from the fuel; (3) estimates of the chemical environment and changes in it including the burns to provide in-reactor transport information; and (4) building condition information, including the effects of the fires, to provide release information, particle size information, and chemical form information for the environmental release.
For the backward estimate, information that will be sought includes:
(1) qualified data on nuclides observed, including chemical form, concentrations, and timing; and (2) hour-by-hour information on wind speed of direction and precipitation for the time period of transport for the area between the reactor and the site where radionuclides were observed. Data feedback from the consequences work described below will be utilized here.
3.2.2 Dispersion of Radioactivity The dispersion of radioactivity in the environment can be either in the air or in surface or groundwaters.
3.2.2.1 Meteorological Conditions Radioactive material released to the air will be carried by the wind, and, depending upon the material's characteristics, may be deposited on the ground
12 or washed out of the air by precipitation. For an understanding of long-range transport by the winds, the meteorological conditions should be determined at all pertinent altitude regimes. The interaction of the dynamics of the radioactivity release with the meteorological conditions at various heights determines the direction and speed in which transport occurs and the degree of dilution as a function o.f distance traveled. It also determines the opportunities for depletion of the material by deposition on the ground or by washout by precipitation. It appears that in the Chernobyl accident some material was initially released near ground level, and some, as a result of the explosion, was released at higher elevations where it could be transported downwind at greater speeds. Because there was little precipitation during the early days of the accident, there was little chance that the mix of radioisotopes was altered much by washout.
3.2.2.2 Hydrology Radionuclides may enter surface and ground waters by washout of the plume by precipitation, by runoff transport of material deposited on the ground and on vegetation, or by release to the groundwater from core material which has melted its way through the plant structure. The geohydrology of the site can be estimated from the proximity to the river, and from the news reports of the site characteristics.
13 3.2.3 Radiation Consequences 3.2.3.1 Individual Doses This task is to determine time-dependent radiation dose rates to individuals in the vicinity (out to perhaps tens of miles) of the Chernobyl site. In particular, the doses and dose rates to individuals from the passing plume via submersion and inhalation should be calculated and/or measured. The effect of buildings on reducing these doses should also be established. In addition, the dose and dose rate from radionuclides deposited on the ground should be calculated and/or measured.
Where possible, physical data from individuals in the plume pathway should be examined to establish more fully the actual doses received by the population.
For example, results from examination of blood samples would be useful.
The purpose of this information is to characterize the effects that such accidents have on the local population and to learn procedures that may reduce the individual doses.
3.2.3.2 Population Doses The integrated dose to populations exposed to the released radionuclides via the pathways described above should be evaluated. Populations with integrated exposures down to about 100 mrem should be included. Consequently, populations at great distances from the site (on the order of 1000 miles or more) may be covered by this evaluation. In addition, measures of radionuclide content of
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foods should be established, so that the doses due to food consumption can be calculated. .
3.3 Emergency Preparedness and Response 3.3.1 Emergency Plans Attempts will be made to ascertain the extent and nature of emergency plans that were in place for the Chernobyl facility. Sone questions in this subject area have already been forwarded to the IAEA through the State Department. Of interest here is information as to what onsite and offsite aspects are included, any established emergency planning zones, any plans establishing decision responsibilities in the plant and offsite, any predetermined criteria for initiating protective actions, and details of any alerting and communication arrangements.
3.3.2 Experience with Protection Actions Taken We would benefit greatly from the Russians sharing the valuable, actual experienes they gained from the Chernobyl event regarding the protective actions they took. Some questions in this area have been sent to the IAEA through the State Department. The U. S. medical team, other U. S. agencies, and other sources may provide additional information.
Information on the evacuation experience will be sought. This includes the time needed to assemble information needed for decision, the further time taken to reach a decision to evacuate, and the time needed to notify the public of
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I the decision; the number of people involved, the timeframes, transportation modes, and other key details; any problems encountered; and any spontaneous (unordered) evacuations and any problems encountered in connection with them, if they occurred.
Any special protective actions for workers or public, other than evacuation, would be of interest. Radiological monitoring, victim identification, and medical treatment referral approaches are additional areas on which information will be sought.
Information will be sought on Soviet guidance as to acceptable levels of radiation exposure, as well as on control room habitability during and after the accident and how the facility was manned and how and from where the emergency was managed, with respect to plant actions and offsite actions.
3.3.3 Decontamination, Relocation, and Reentry Information will be sought on decontamination techniques used to achieve dose savings and to recover access to property, including any " simple" decontamination techniques reconnended to the general public for use in dealing with low level contamination.
It would be of interest to examine what criteria are being used to determine the areas that people can reenter, the arcas from which people must be relocated on a long-term basis, and the areas which people may be allowed to l reenter once decontamination efforts are conducted; how the contaminated
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t 16 materials are being handled and disposed of; and what kind of radiological monitoring program is being implemented for the contaminated, decontaminated, and disposal areas.
- 4. Coordination The accident at Chernobyl has gained the attention of virtually all organizations worldwide that are involved with the generation of power from nuclear energy. This includes government regulation and energy development agencies, nuclear vendors, utilities which own and generate power from nuclear plants, scientific organizations involved in nuclear research, as well as organizations that promote and criticize nuclear power.
Many of these organizations have scientists and engineers who are highly knowledgeable in nuclear plant systems and components, and have or could provide valuable insights and knowledge regarding the fact-finding tasks. The following two sections will describe the coordination efforts to be undertaken both within the U. S., and internationally.
l i 4.1 Industry and Other U. S. Government Agency Efforts Many U. S. industry organizations have Chernobyl design information available, studied available literature about the Chernobyl design and have reported on design comparisons to U. S. reactors, as well as speculated on the more likely accident initiators and accident scenarios. In order to effectively tap this l
l 17 valuable source of information, the NRC will encourage the involvement of these
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organizations in the fact-finding program. l The DOE and FEMA in particolar will have a formal program to develop the facts surrounding Chernobyl. Some information concerning the aftermath of Chernobyl is expected to come through the State Department. Close coordination with the NRC program is expected.
Some organizations, in particular national laboratories and universities, will be retained unde. .v:ni.ical assistance contracts to assist the NRC staff in certain areas of fact finding for which they have recognized expertise. Other organizations. such as nuclear supply vendors and utility and industry groups will be asked to participate voluntarily, primarily in providing insights, comments, and suggestions. In the Appendix, we have made a preliminary identification of the expected involvement of each group for each aspect of the fact-finding program.
4.2 Internaticra,1Effgrts In addition to domestic organizations, there are international efforts underway to ascertain the facts regarding Chernobyl. Some of these efforts are currently planned to go beyond fact finding, and the NRC will be participating in them. This participation will provide an excellent opportunity to obtain detailed factual information.
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18 4.2.1 International Atomic Energy Agency TheInternationalAtomicEnergyAgency(IAEA)isanorganizationubderthe auspices of the United Nations. Following the Chernobyl accident, the IAEA convened a meeting to plan a series of future meetings to be held that will address specific follow-on activities related'to Chernobyl.
l Specifically, NRC will participate in several upcoming IAEA meetings over the next several months. The first will be a meeting, expected in July,~during which the Soviet Union will report on the causes of the Chern6byl accident.
There will also be meetings in which binding international early warning and coordination agreements will be drafted. There will be a meeting of worldwide experts that will develop and propose ways to improve safety. The final meeting will be a conference of governments convened to. consider the reconnendations of the experts meeting. In addition to these meetings, there is also underway a general movement to strengthen the role of the IAEA in responding to accidents such as Chernobyl. For example, the role of the Operational Safety Assessment Review Teams will be strengthened through mechanisms such as increasing the inspection frequency. Full participation in the Incident Reporting System, including detailed reports on all reportable events, will receive renewed attention by participating countries.
We have been informed that the International Nuclear Safety Advisory Group, which advises the IAEA Inspector General, will also be strengthened. Finally,
19 other U. N.-sponsored organizations, such as the U. N. Scientific Comittee on Effects of Atomic Radiation, and the World Health Organization will become more actively involved in responding to nuclear accidents.
4.2.2 Comittee for the Safety of Nuclear Installations (CSNI)
In addition to participation in IAEA activities, the NRC also participates in the activities of the Comittee for the Safety of Nuclear Installations (CSNI).
This Comittee operates under the auspices of the Nuclear Energy Agency, which is an agency of the Organization for Economic Cooperation and Development (DECD). The OECD is primarily made up of Western industrialized nations, and does not include Soviet bloc countries, whereas the IAEA does.
While there are no specific plans formulated yet for CSNI activities related to Chernobyl, it is expected that some specific activities will be identified shortly. The NRC will monitor these activities and participate in them as appropriate. Information developed that is useful to the fact-finding mission will be included in the effort.
4.2.3 Other International Efforts The NRC maintains close liaisons with individuals in counterpart organizations in many of the industrialized, western countries. Through these liaisons, we will complement our fact-finding effort.
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- 5. Implications Assessment Program The objective of the fact-finding program is to develop a factual b$se concerning the causes and evaluation of the Chernoby1 accident, and the design of the Chernobyl reactor. The second phase of the NRC's program is the assessment and evaluation of the factual data in order to either confirm the staff's initial judgment that no actions on operating U. S. plants are warranted, or to identify certain areas which require either immediate Commission action or more detailed evaluation (e.g., cost-benefit analysis).
In order to ensure that the implications assessment program provides a thorough, unbiased evaluation, a steering group consisting of' senior NRC managers will oversee this effort. The proposed makeup of this oversight group is as follows:
21 Implications Assessment Program Senior Management Oversight Group Harold R. Denton, Director, NRR Thomas Murley, Regional Administrator, Region I Clemens Heltemes, Director, AEOD James Taylor, Director, IE Denwood Ross, Deputy Director, RES Guy Cunningham, Executive Legal Director Jares Sniezek, Deputy Executive Director for Regional Operations & Generic Requirements James Shea, Director, IP l
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22 0 RAFT AFPENDIX A Possible Inter-Agency Work Distribution for the Fact-Finding Program
LEAD CONTRACTOR OTHER ORG .
NUCLEAR DESIGN 1/ ,
- Detemine the magnitude of the various DOE reactivity coefficients and their .
variation with burnup, core configura-tion and power.
- Determine the variation of power and temperature distribution with burnup and core configuration.
- Determine the reactivity effects of j individual fuel and control rods under various operating conditions.
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- Detemine the dynamic behavior of the power and temperature distribution for various reactivity and coolant flow transients. 2/
- Identify any experimental data that can be used to benchmark computer codes used to analyze the nuclear design.
1/ Could require development of methodology and engineering data.
-2/ Interfaces with the T/H design activity.
LEAD CONTRACTOR OTHER ORG ,-
T/H DESIGN 1/
- Determine the bases and methods for primary DOE coolant flow regulation, steam production and I pressure relief.
- Determine the static temperature distribution in the reactor (including the graphite) and how it varies with burnup and operating conditions.
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- Determine the cooling requirements and characteristics for the control rod systems
- Determine the system response to overpressure and overpower events. 2/
- Determine the system response to various loss of flow and loss of cooling events. 2_/
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1/ Could require development of methodology and engineering data.
- ]/ Interfaces with the T/H design activity.
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- LEAD CONTRACTOR OTHER ORG CONTAINMENT /CONFINMENT DESIGN
- Determine the boundaries for the various - NRC containment volumes.
- Determine the design capabilities (pressure and temperature) and the design bases for the various containment volumes.
- Determine means and capacities for pressure relief to the suppression pools .
- Determine the characteristics of the graphite s j r
inerting systems including leak detection, make-up system, monitoring system, and pressure re' lief
LEAD CONTRACTOR OTHER ORG INSTRUMENTATION AND' CONTROL
- Identify the various nuclear and process' DOE instrumentation requirements relevant to safety in the Chernobyl plant.
- Identify the various trip functions and set points.
- Determine the operating characteristics (mechanisms and movement times including l
scram) of the control rod systems.
- Detemine if burnable poisons are used in conjunction with rod control
- Identify any alternate and/or diverse gf systems to back-up rod control l
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LEAD CONTRACTOR OTHER ORG REFUELING
- Identify the refueling requirements, DOE mechanisms and procedures.
- Determine the cooling requirements and related power and time constraints associated with refueling at Chernobyl.
- Identify possible failure modes that
's could lead to reactivity insertion, '
voiding of the fuel channel or release of graphite inerting gas.
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LEAD CONTRACTOR OTHER ORG ELECTRIC POWER
- Identify the functional requirements for ~ NRC electric power (AC & DC) including cases for abnormal, upset and emergency cor,ditions.
- Determine the capsbilities of emergency power at Chernobyl (including DC and diesel power) including reifability.
- Identify any systems shared with other ,
7 reactors at the site i
LEAD CONTRACTOR OTHER ORG ACCIDENT ANALYSIS
- Identify the accidents analyzed for the
- NRC Chernobyl plant.
- Determine the design basis accidents used for various aspects of the design.
- Identify any considerations and analyses l provided for beyond the design basis accident (e.g., severe accidents including degraded or core melt accidents).
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- Determine if there is any independent review of the accident studies performed by the designers of the plant. If so identify the nature of the review.
- Determine cause(s), scenario's and consequences s, /
of Chernobyl accident.
PLANT OPERATION (PROCEDURES / TECH SPEC, ETC.) LEAD CONTRACTOR OTHER ORG
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- Determine the degree of training required EPRI/INPO and provided for the operating crew at Chernobyl.
- Identify plant procedures used for operation l
(including tech specs or the equivalent, as applicable).
- Determine if simulators are available for operator training and plant performance ss /
analysis 1
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LEAD CONTRACTOR OTHER ORG SAFETY SYSTEMS
- Detemine the functional requirements and design basis for the suppression pool system at Chernobyl.
- Identify and other safety system requirements at Chernobyl.
- Detemine the functional requirements and design basis for the other safety systems identified above.
- Identify the ultimate heat sink and I detemine its adequacy
MATERIALS LEAD CONTRACTOR OTHER ORG
- ?.ssemble various U.S. and foreign information DOE on reactor graphite including structural properties, corrosion susceptibilities, therwal transient response, including the Wigner Effect i irradiation behavior and chemical reactions over ranges of temperature and concentrations with
> steam and air.
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- Provide a similar assemblage of information on other materials used in Chernobyl such as for control rod, reactor supports, containment structures, primary and secondary systems, and i
fuel.
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- For all materials used in construction, determine if construction was intended to be performed in s/
conformance with codes and standards. Determine if such codes and standards have significant differences from the ASME Code,Section III, and other codes used in the U.S., and U.S. quality -
assurance provisions.
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LEAD CONTRACTOR OTHER ORG SITE CHARACTERISTICS
- Develop an understanding of the Chernobyl NRC site characteristics regarding site geography and hydrology.
- Develop an understanding of the Chernoby1 y site characteristics regarding geology and seismology.
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4 LEAD CONTRACTOR OTHER ORG STRUCTURAL DESIGN
- Develop an understanding of the approach used DOE for Chernoby1 in the design of structures, components, equipment and systems to accomodate dynamic accident, seismic, wind, tornado and flood loads. This includes the containment /
confinement / suppression pool structures and
, building foundations.
P I
r SOURCE TERM LEAD CONTRACTOR OTHER ORG
- Determine core inventory of radionuclides NRC at time of accident based upon power history of reactor and status.
- Establish time at which reactor began releasing radioactivity into the environment.
- Determine the release rate, chemical composition, and other physical .
parameters of the radionuclides. l t
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- Determine the physical and chemical sj/
behavior of the radionuclides immediately after release from the reactor core.
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ENVIRONMENTAL BEHAVIOR LEAD CONTRACTOR OTHER ORG l
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- Determine the radionuclide factors such NRC as plate-out and fall-out that occurred within 100 meters of the reactor.
- Develop a model that characterizes the DOE radionuclide transport within 50 mil.es of the site. Focus on factors that affect radionuclide plume behavior within 2 miles of site.
- Determine long-range radionuclide behavior 7 including plume submersion, rain-out, fall-out, and resulting ground contamination.
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e 00SIMETRY/ HEALTH EFFECTS LEAD CONTRACTOR OTHER ORG
- Establish radiological doses received by NRC members of the site workers via submersion, inhalation, & ground deposition pathways.
l For these same pathways, detemine doses j received by members of the public.
f Establish shielding factors afforded by l housing and other structures.
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- Using extent and pattern of ground contamination, estimate long-tem food chain effects. Determine uptakes and subsequent radionuclide concentrations 1 in food products.
- Establish a health registry to follow i
the long-term medical history of the Y ,
exposed population. Data can be compared HHS to Hiroshime/ Nagasaki base.
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O EMERGENCY PLANNING LEAD CONTRACTOR OTHER ORG
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Joint FEMA /NRC e
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