Introduction

The Union of Concerned Scientists (UCS) is a Cambridge, Massachusetts-based coalition of scientists, engineers, and other professionals who are concerned with the impact of advanced technology on society. During the last 2-1/2 years we have been engaged in an intensive technical study of nuclear power plant safety. We, and now others, have found the safety assurances to be gravely defective. More recently, we have completed reviews of other aspects of the nuclear program. Since a large nuclear power plant construction program is underway in this country and throughout the world, public understanding of these critical issues is now an urgent priority.

This overview sets forth the principal conclusions of our investigations. It brings into focus some of the important public safety problems associated with nuclear power. For the convenience of those who wish to investigate the nuclear safety problem further, we have provided extensive references. Other groups of scientists have carried out independent reviews of our conclusions.

reviews are presented.

The Reactor Safety Problem

Summaries of these

We believe that nuclear power plants, as now designed, present a serious threat to the health and safety of the public.

The safety systems installed in presently operating

-2

nuclear power plants are crude and untested. A number of

design weaknesses in these safety systems have been confirmed. Moreover, there is extensive evidence that the workmanship going into nuclear power plant construction is far from adequate. The increasing number of quality assurance problems, maintenance ́deficiencies, management review oversights, and operator errors is disturbing. The Atomic Energy Commission (AEC) itself has acknowledged that there have been a number of "near misses" in the brief operating history of commercial reactors, accidents that could have resulted in major public health incidents. An official AEC assessment of some of the operating records of the nuclear reactor program is that the absence of direct injury to the general public to date is "largely the result of good luck.

The Consequences of a Major Nuclear Power Plant Accident A major accident in a nuclear power plant has the potential to create a catastrophe of very great proportions. In 1971 UCS carried out a technical assessment of the consequences of such an incident.

**

In this study we applied

knowledge acquired in previous studies on the effects of nuclear weapons explosions. The AEC has itself completed a secret study on the consequences of a major nuclear power plant accident; the results of the AEC investigation have recently been made public, although not voluntarily, and confirm our independent assessment.

AEC Division of Reactor Licensing, Reactor Operating Experiences, ROE-69-9.

*** Ian Forbes, Daniel F. Ford, Henry W. Kendall, James J. MacKenzie, Reactor Safety: An Evaluation of New Evidence, Union of Concerned Scientists, July 1971.

-3

The size and scale of a reactor accident is the

consequence of the prodigious quantities of radioactive material contained inside these complicated machines. A typical nuclear power plant routinely contains a quantity of radioactive material that is approximately equivalent to the radioactive fallout from thousands of Hiroshima-size nuclear weapons. An appreciable fraction of this radioactive material is gaseous in form and could be easily borne away by the wind if accidentally released by a nuclear power plant accident. A release of even a small fraction of a reactor's inventory of radioactive material could, depending on weather conditions, cause lethal injuries at distances up to several dozen miles from the reactor and damage to health at far greater dis-. tances. The AEC's secret study of the consequences of a major reactor accident estimated an "area of disaster... */ equal to that of the State of Pennsylvania.

Given the defects in nuclear power plant workmanship, operating procedures, and safety systems, discussed below, we believe that the possibility of a major accident involving

a catastrophic release of radioactivity into the environment is very real.

The "ECCS" Controversy

The "ECCS" emergency core cooling system

is a

very basic reactor safety system. Its function is to restore

AEC internal memorandum from Albert P. Kenneke, Minutes of Steering Committee on Revision of WASH-740, January 28,

-4

cooling water to the hot nuclear reactor core in the event that a a pipe rupture causes loss of normal cooling water. If this backup cooling system fails to work effectively, the reactor core would overheat and the stage is set for the kind of major radiation release into the environment described

It has become apparent from our technical studiesTM that very much less than the extremely high level of diligence required has been devoted by the nuclear industry to reactor safety system design and testing. An array of design defects in present ECCS is apparent. The ECCS testing program has been narrow in scope and of a calibre very much below the capabilities of engineering science. There is a large backlog of unanswered questions about the most basic aspects of ECCS performance. It is clear that adequate experiements

to confirm ECCS effectiveness have not been carried out. Moreover, our study of the limited experiemental data available suggests that there are a number of independent reasons why present ECCS might fail if called upon.

The assessment that ECCS effectiveness is inadequately supported in AEC claims is quite widely shared by the community of scientists familiar with reactor safety technology. The

*/ Daniel F. Ford and Henry W. Kendall, An Evaluation of Nuclear Reactor Safety, Volume I, Union of Concerned Scientists, March 1972;

Daniel F. Ford and Henry W. Kendall, An Evaluation of Nuclear Reactor Safety, Volume II, Union of Concerned Scientists, October 1972;

Daniel F. Ford and Henry W. Kendall, An Assessment of the Emergency Core Cooling Systems Rulemaking Hearing, Volume III, Union of Concerned Scientists, April 1973.