ML20205T431
| ML20205T431 | |
| Person / Time | |
|---|---|
| Issue date: | 11/03/1988 |
| From: | Zech L NRC COMMISSION (OCM) |
| To: | Protsenko A UNION OF SOVIET SOCIALIST REPUBLICS |
| References | |
| NUDOCS 8811140254 | |
| Download: ML20205T431 (3) | |
Text
_ _ _ _ _ _ - __.
l .
. .e a ne:
l* *
%, UNITED STATES
! .,., 7 e NUCLEAR REGULATORY COMMISSION 4 ,
{ q ,i waswiNotoN,0, C. 20046 fh
% , , , , ,.* November 3, 1988 CHAIRMAN ,
I f
Mr. Alexander N. Protsenko, Chairman !
State Committee for Utilization of l Atomic Energy ;
Staremonetnyyper, 26 >
- Moscow t 109180 U.S.S.R. l
Dear Mr. Protsenko:
During our discussions in Vienna, we talked about the U.S. I Emergency Classification System vis-a-vis the French Accident i Severity Scale. I said that I would provide you with more t i
detailed information regarding the U.S. system. I hope the j enclosed material will prove useful. [
I Sincerely, t
M W.
I lando W. I c , J (j {
i
Enclosures:
i i
- 1. U.S. Emergency Classification System - A Brief Overview (
- 2. huREG-0654. Revision 1. Criteria For Preparation anc !
Evaluation of Radiological Emergency Response Plans and !
Preparedness in Support of Nuclear Power Plants i i
l I
?
r l
l i !
{!g y jfd!((d x t
l
U.S. Emergency Classification System - A Brief Overview The U.S. Energency Classification System is an integrated part of radio-logical crergency response plans prepared by utilities and state and local governments, to meet the requirements of Title 10. Code of Federal Regulations, Section 50.47. The Emergency Classification System consists of feur Erergency Action Levels (EALs), as follows:
- Unusual Event: Unusual events are in process or have cccurred which indicate a potential degradation of the level of safety of the plant. No releases of radioactive material requiring effsite response or monitoring are expected unless further degradation of safety systems occurs.
- Alert: Events are in process or have occurred which involve an actual or potential substantial degradation of the level of safety of the plant. Any releases are expected to be limited to small fractions of the Environmental Protecticn ' ency (EPA) Protective Action Guideline exposure levels.
- Site Area Emergency: Events are in process or have occurred which
, involve actual or likely major failures of plant functions reeded for protection of the public. Any releases are not expected to exceed EPA Protective Action Guideline exposure levels except near site boundary.
- General Emergency: Events are in process or have cccurred which involve actual or icninent substantial core degradation or welting with potential for loss of contairrent integrity. Releases can be reaserably expected to ex(eed EPA Protective Action Guideline exposure levels offsite for more than the imediate site area.
The U.S. Emergency Classification System was established to assist utilities, states, and 1ccal governments, and the Nuclear Regulatory Coernissicn (f$C) to corrrunicate ef fectively as socn as an event occurs, and as it progresses, in order to assure that its significance, and its cotential significance, is irrrrediately conveyed to responsible state, local, and regulatory officials to aid in protective action decisien making. This classificatien system is incorporated into utility, state and local governments, and federal agency plans, precedures, and training as guidance fer decision making. The U.S. system involves notifications, using the four levels of classificatien defined above, from the utility to state, local, and federal officials, starting within 15 minutes of the event initiation, to enable these officials to follcw the course of the event and to rake an informed judgment on the need for imediate actions to protect public health and safety.
i .
1 1
Experience with the U.S. Emergency Classification System during the past ;
j 8 years, and particularly durino simulated emergency drills and actual 1 plant incidents, has proven its worth and practicality. Because the i
- system involves the early notification of events, ineleding those of relatively low safety significance, state and lecal officials have developed a high degree of confidence in its effectiveness.
Based on our understanding of the French Accident Severity Scale, the ;
event classification level is detentined af ter the event in order to -
provide "...a better understanding of nuclea- issues by the media ano the public." Specifically, the French system attempts to rake a clear ;
distincticn between nuclear incidents (Levels I to !!!) and nuclear accidents (Levels IV to VI). Events which turn cut not to be "significant" are not classified.
Based on NRC participation in a number of emergency drills and on !
discussions with a wide range of officials, increasing the number of ,
classificacion categories in the U.S. system would neither enhance '
- comrrunication ror improve safety, but could lead to unnecessary !
! discussion and analyses that could detract from important protective .-
1 action decision making ouring the early stages of erercency response. (
) Thus, the NRC is reluctant to censider changes to the four EALs currently i j in use in the U.S.
J l For a more complete discussion of the U.S. Emergency Classificatien i q System, please refer to Appendix 1 of the enclosed NUREG-0654. !
] I j i b
l '
j i
[
[
i 1
l I 8
l i :
_ . .