ML20234E772
Text
...
r ;:; y, ;., w..,
_., n
.. ~
h F
[
\\.
o Comments on Safety Aspects of Nuclear Reactors l
1.
k j
-i f
L. H. McEwen j
l Manager, Nuclear Safety Engineering Atomic Power Equipment Department
)
General Electric Company 175 Curtner Avenue San Jose, Oclifornia 1
s l
~
- 4 1
F J
l
(
C:! /
/
v l%/
/
'/
Q
'Q de h D
~
m e.:
6-6 4- -3 1
ty 4....
May 19, 1964 4 4 ;.a
- v.
2.?
'1 C
c) 8709220513 851217 PDR FOIA 4
FIRE. STOBS,-665 PDR
,_m a
.- :g_j
,, z
... = + c.:.,,m,
t p.
I 1
k p
.e I am Larry McEwen, Manager of Nuclear Safety Engineering in the Atomic Power Equipment Department of the General Electric Company; my Department of the General Electric Company is to design i
and provide the nuclear reactor portion of the power plant proposed by the Pacific Gas and Electric Company for location at Bodega Bay i
i My Company has been engaged in the atomic energy program l
~
for about 18 years.
Our participation includes operation of the Hanford plant, a platonium production center in Washington State;'
t the Knolls Atomic Power Laboratory, a naval reactor center near f
f Schenectady, New York; and gas-cooled reactor facilities in Ohio f
and Idaho.
t.
1 This broad experience has involved the design of many reactors: Research reactors, test reactore, plutonium production f
reactors, aircraf t and naval reactors, and civilian power reactors.
j i
The reactor types includq graphite reactors, fast reactors, j
gas-cooled reactors, pool reactors, pressurized water reactors, I
i j
heavy water reactors, superheat reactors and boilidg water reactors.
t t
This 18 years of experience includes the long term operation and maintenance of reactor plant facilities.
By my count, the General Electric Company has either designed or operated, or both, a total of 61 nuclear chain reaction facilities, and if plants now under design or construction are included, it turns out that the Bodega Bay l
i i-
, - n.m ON,1.~ ' ~ ~ ~,., z..,.. ----.-.
....,. --.-.- :.,.:. $ 7;_--
. a..;..j.
.._.,....,........n..;....
,. =
g..
. =...
.u.
.)
(
(-
~
p reactor is the 75th unit with which we have been associated.
Of these, more than'40 are what may be called large reactors.
The-plant most recently started-up, the NPE in the State of Washington,'
which is now proceeding through the usual sequence'of careful tests as it is brought to full. capacity, is scheduled for.an electrical output'of 860,000 kilowatts, more than two and one half times that of the Bodega Bay reactor.
General Electric employees-today operate 15 reactors, and through the past 18 years.have i
i y
logged about 200 reactor years of experience.
j
?
k
{
Safety has always been important to us, and we are proud' l
l that despite the tens of thousands of employees engaged in this work, throughout this entire 18 year period, not a one has sustained
~i observable harm from radiation accidents,. and that persons not_ on the plant premises have never received radiation exposures in excess i
I of applicable limits established by the Atomic. Energy Commission or j
other bodies, j
I
{
Ten years ago, when there were about 27 reactors-in this q
country, it was fair to say that'they were a novelty.
They are i
certainly no longer a novelty to the General Eleetric Company.
)
Reactors of our design exist in nine states and seven foreign countries.
On a national basis _there are now 205 operable reactors, and a total of.about 1100 reactor years of' experience have been
~
logged.
This does not include what are termed critical facilities, a special sort of small reactor; if thece are included, the totals grow to more than 300 operable units for which about 1500 reactor 4 6
_ ~;r t: - ~~ - : =.~h
___--.a, - -,=.-__.- Q m ? -. _ _ - - _ - - _ - _ - - - - - - - _ -
- . = vs sm---L==-.:v-w i; m:.,;;. w : - m =.n
.a
.1.
. 4
. -.; =.=.S =..-...... -.g
- .,,.~..:..,w._._
.=
1 1
-g 4
/
s years of experience apply.
The fact that so many reactors operate so uneventfully-may come as a surprise to people who have been alarmed by exaggerations about atomic energy.-
Identical basic physical principles govern the operation of all reactors and these principles are by now qv.te reasonably understood. 'There are important differ-ences between. individual. units, of course, and the variety of first-of-a-kind reactors at the National Reactor Testing Station in 1
I Idaho is dramatic.
However, with the possible exception of
(
f 4
-h j{
f special devices. involved in weapons development, all_of these
[
facilities share the property that they cannot explode like an It is difficult to 4
atomic bomb.
The reason is straight-forward.
3 make an atomic bomb.
What is required is not' only highly concen-I trated fissionable material of great purity, but also some way.
to compact this in a very special way.
Irs each cubid mile of the F
ocean there is enough fissionable material to make a' nuclear chain reaction.
Why do the oceans not explode?
The fissionable l
materials there are simply too dilute.
So it is in reactors.
In s
the Bodega Bay reactor, for example, the readily fissionable r
material, Uranium-235 will be diluted about 40 parts to one, with Uranium-238, the other variety of uranium.
California plays an important role in today's nuclear world.
You may be surprised to learn that there are 35 nuclear facilities in the State; 13 in the San Francisco Bay area itself, - :-
,. -,sa:- :
_._; w..;
.h
'- =,,,,.
ma
~ og:
l
- g c
not including the eight nuclear submarines already built at Mare Island, where five more are indicated to be-now under or scheduled for construction.
My Department of the General Electric Company has its headquarters in San Jose.
At our Vallecitos laboratory, near Pleasanton, about 600 employees are engaged in research, or in the operation of five nuclear facilities.
Two of-these, the General Electric Test Reactor and the brand-new-Vallecitos 1
Experimental Superheat Reactor, are the largest reactor plants j
closest to the City of San Francisco, except perhaps for the nuclear submarines operating in the bay.-
Incidentally, until quite recently, we also operated the Vallacitos Boiling Water j;
I Reactor, which was retired from service last year simply. because-its job in developing boiling water reactor technology wat. completed.
5 In San Jose, about 1,200 General Electric employees are I
};
engaged in the design of reactors, or in the manufacture of reactor
- , l c
components and fuel.
It is our intention-to. manufacture there the fuel for the Bodega Bay reactor, and for other reactors as well.
The fissionable material for the reactor will be shipped to our factory and there made into fuel elements.
The safety of these operations is of course under AEC scrutiny, under terms of the license they have granted us.
You may recall that others have told you that the fissionable materials content et the Bodega. Bay reactor will be 1500 times more than that of the Hiroshima weapon, and that this is T
-4
..y m :,2 :, m..;.
,:4 = m p., m.m m. # g # w..,.: m g p ;;;;; r ; :.-
, mq,,
,q
i i
I g
evidently shrugged-off by the " experts"~on the basis of a concept known as " overkill".
How does our fuel plant and its safety features fit into such a picture?
It is quite likely that more than one reactor load of fuel will be in our San Jose factory at any given time, and from what otheru have told you evidently this will be even more than 1500. times the fissionable material in the Hiroshima weapon.
We would be very happy for you to visit our fuel i
factory; you might be surprised to find no thick walls of concrete e
h and steel; the place.looks much like many other manufacturing: plants.
d It is assuredly subject to shaking in an earthquake, and is about i
as close to your city as Bodega Bay.
May I ask you to reflect _a.
i i
little on this?
Is it possible that government agencies charged with the regulation of safety are totally irresponsible in the matter of our fuel plant, because of some sort of evil influence
{
exerted over them, or because of zeal to promote atomic enterprise?
N tj Is it possible that the General Electric Company would carry out an i
L
(
enterprise with so obvious a disregard for the health and safety of the citizens of San Jose or of its own' employees?
If this is so,
~
a man such as I must be out of his mind to work in such a place.
I suggest there to be an alternate possibility;.that-a 1
basic principle exists, widely known throughout the nuclear community, which states that the sheer quantity of fissionable l
material in any place, despite'its usefulness as a scare statement, is simply not the proper measure of its potential hazard.
a ~
~ -: r...., m...,-.
,, 3 y. m. e ; n., 7 g g.;u 4,g.s.,;.
n,..,, g
s T.
More importantly, I suggest that you ask yourself this question:-
" Exactly what is the nature of the information received when a-man stands in front of you and says, ' Personally, I do not know anything about reactors, but... ?"
When mention is made of tigers, this.is'all very cute, but is not the real question whether somebody who knows about tigers and about cages has made a judgment' as to adequacy?
What is the substitute--a popular vote by those who know neither tigers nor cages?
I think common sense indicates i
the proper answer.
1 i
You were told, and in awesome terms, about an absolute i
physical impossibility--all the fissionable material from the Bodega Bay reactor scattered on the City of San Francisco--and with allusions to some sort of a vaguely defined expert source for the information.
My own office is 100 yards from our fuel i
j factory, where there is, I assure you, quite a store of fissionable.
tj material.
I am not an expecially healthy man, and you may observe L
that I have a bad cold today.
But as I stand in front of'you, I ask:
'"Am I dead?".
Remember,I am the man who works each day just 100 yards from a treunencous aggregation of fissionable material, j
the same stuff you were told could make you fair city uninhabitable I
for 100 years.
I simply ask you--have you been informed or have you been misinformed?
Perhaps it indicates good reason to refer resolution of these matters.to those who can sort out atomic fact 4
from atomic fancy, based on personal ability to distinguish ths two.
3
-l a
.,j
- * * * ~
- E,,,.w-.-.. -..c....-_...__.,.,.., m.y,,,,.y.., y.,..~.. ' ',y.1.,
,.y,
.y
,.).g.. _. ;,
yy
.._-.---u-.
E O
It. turns out, for example, that'I cannot confirm the assertion that the Bodega Bay reactor would contain 1500 times as t
much fissionable material as the Hiroshima-weapon.. The reactor will centain about 4000 pounds of Uranium-235. < So far. as I' have been able to determine from the Atomic ; Energy Commission, the amount I
.j of fissionable. material used in the Hiroshima weapon is still a classified military secret.
Thus I cannot calculate the ratio.-
7 g
O The potential hazards.of reactors arise almost entirely
{
~
l from the fission products in them, not the fissionable materials
~
themselves, and I happen to know that the curies of fission products
{
f j
released when the Hiroshima weapon exploded are more.than two hundred times as much as would be the total fission product' l
inventory of the Bodega Bay reactor.
Perhaps this is a more i
meaningful comparison, but I do not think so.
'1he facts are that j
reactors and weapons are so dissimilar that side-by-side comparison
'I is not meaningful, especially when it involves a. sort of numbers game played in front of a lay audience.
l Reactor engineering has been my business for the past 13 years.
I have worked on and around reactors and have.come to know quite a bit about them.
You may consider me an atomic expert if you wish,.although I dislike use of the term because'it seems so widely' applied these days--to..anyone with a college degree of any
. kind, providing he somes from another county--the further from home, the' greater the expert principle-and whether or not he l
' i o
2
,,,,,,...-,.,,., _ _ _,., g.
..,n.,,,.
v
,y
(.' '
()_
1 t
1 knows much or even anything about reactors.
.My own experience includes ten years of work. literally in the shadow of large reactors.
I lived with my wife and four children, and fifty thousand other people,about 40 miles from eight big reactors, reactors which lacked contair.cnt features, one_of the important safety attributes of the reactor planned for Bodega Bay.
Except for the inconvenience and hazards of commuting, I' would be:quite happy to live-next door to the Bodega Bay reactor-1 plant.
And, I make no joke about the hazards of commuting; while-
,j F
i f
you have perhaps never looked at the figures in-this way, if present'
'{
}
experience continues, about 150,000 people will be injured.in auto accidents in San Francisco before I would expect the Bodega Bay
[p reactor to be retired because of obsolescence.
I t
l You may wonder about the health of the residents of-
- l Richland,- my fomer home, the so-called atomic city in the State of i
i Washington, which involves'about 8,000 breadwinners working daily 1
11 in atomic facilities.- I think~it is enough to say that death rates l l iI are about forty percent below the average for the state and nation,
{j ii and that the town even became famous for its high birth rate.
Only an irresponsible nitwit would say that this' indicates a beneficial h
effect of atomic radiation.
For example, it might make more' sense e
to attribute the high birth rate to a' youthful population, or to
!j i:
a relatively high proportion of Mormons in the' community; I believe they tend toward large families.- What I believe this record does
. (
'Y
!s
-,- +.,,,,, n a.:n 4,,,,,,,,,,. 7.n -..n,. :,.r
- n.,... -.,-,.,
Q - :3:
.y
.. :. o.
s z.
...a a.
.b
~
i 4
i show, however,'is that relative to all the other factors which affect health in any community, the effect of low level radiation, if any offect does exist, is so minute it cannot be distinguished.
One might even wonder if the superior. health in Richland could be attributed to some simple factor such as clean air, which we in the San Francisco Bay area do not always have, and which I expect causes you concern.
i Within General Electric the main stream of our central i
{
station power reactor activities involves what is termed the boiling h
water reactor concept.
This is one of the sirdplest and most i
direct methods of using nuclear energy for pown production, and i
was one of the first power reactor types conceived.
Accordingly, 5
i j.
therefore,.it is a reactor type which at thin time is very well
[
understood, is widely applied, and for which considerable success-
+
i ful operating experience has been logged.
This is the type of nuclear reactor proposed for Bodega Bay.
5 Operating boiling water power plants of our design now i
in service include those near Joliet, Illinois; Frankfurt, Gemany;
)
Naples, Italy; Tokai Mura, Japan; charlevoix, Michigan; and Eureka, California.
Plants under contract include those in Ihdia, Holland, and Germany, in New Jersey and in New York State.
While these plants -differ in size and in details of design, they all operate on the same basic principle--that of simply using nuclear heat to boil watar, and thus to take the place of the usual oil, gas or coal-fired boiler used in conven'tional power stations. 1 l
.;......__._,,,,.L..~,.~~~".'"~,..__.,.
- ~ ~ ~ ~ ~ ~~ 2 :~ ~ ~:
....__... ~. _ - _,
,.p....,.
.._...,_.g
1 f
U-i r
1 In one respect all these boiling water reactors are re-markably similar.
They are built on a modular principle.- Each module involves four fuel bundles and what we term a' control blade.
When.a customer wants a smaller or larger reactor,-we simply change l
the number of modules.
I am not embarrassed to admit that we some-times tell our customers that design to their specific requirements is more involved than this.
It usually is, because we must, in.
[
addition, carefully optimize, the design of non-nuclear portions of'
[
- f. -
the plant to suit these requirements.
I) l l
i e
i
[
The processes used to make electricity out'f steam from.
o l'
boiling water reactors are the same as those used for years in j
ordinary power stations.
Actually, the steam utilization equipment il in our nuclear plants might be termed "old-fashioned" because the i
steam pressures tend to be less than in ordinary power stations, jl 1i and the service conditions thus less; demanding.
The electricity
}:
I h
produced in these plants is, as you probably know, identically the ll i
same as that produced by conventional power plants.
I!
44 These nuclear power plants are nowhere near as different from ordinary power stations as lay persons might th1nk.
More h
c importantly, they possess intrinsic features <to make their control and operation simple and safe.
Arranging reactors.to have self-contro' ling properties does not represent a sort of near-magic l
achievement with roots in deep mystery which I cite now to show the extreme skill of nuclear designers.
On the contrary, the principles 5
'-4 r;* y y -y,-wr.+ y.s.y q s.y p, p rg-gr 7;g 7. g f,,.,.e*7.;7;;rg
- y..y.,. 7,,...,7,,,,
.m...
..y.y,,
7,,.,.__
0
?
t.-
r 0
s s
l-which create these properties have been known for a long time; it proves relatively easy to achieve them and this is simply done as
- a. matter of common sense design.
As one example, loss'of water from the-reactor itself stops the nuclear chain reaction regardless of actuation of mechanical controls.
As another example, use !s made of fuel material, an already-oxidized form of uranium, which tends ' to stop the neutron reaction if it heats up.
That fuel of-
~
this sort does indeed stop the neutron reaction when it heats up was again demonstrated'in a'recent test at the National' Reactor-Testing Station.
In this test a special control element was shot
}
out of an open-to-the-air reactor at high speed to charneterize i
what would happen.
In similar tests with other reactors the result was destruction of the reactor accompanied by expulsion of a geyser j
i i
of steam and water.
In the case of the reactor with its uranium
}
in the oxidized state, such as would be used in the Bodega Bay j
i i
reactor, the only consequences of this test were the bending of many 1
\\
fuel rods, the bursting of two, and'to water at all'was shot-out.
j f
The facility remained operable.
This same material, uranium j
u j
dioxide, pre-fired before use to become a ceramie, similar to firebrick, se wes to assure that the fission products it comes to 1
accumulate are not in a mobile or readily dispersed form.-
It is not at all certain that fuel with these preperties, i
the kind of fuel to be used in the Bodega Bay reactor, was.the fuel envisioned by those who in 1956 wrote the so'-called Brookhaven Report - WASH-740, from which some selected extracts have been read.
4.$
ir~~h e ere cm-n,h s&-% ; g-symp-- g ;~.y 7.~p v.v.c: pw~
p~ we-;e-- n t }~Thl-Q +-&.- 'Y..
-+ ~ n my >
- j-
[
.(-_
'(
)
y
+
,o to you.
Perhaps you do not kno'w that this same report likens the
- risk of living near a reactor 'to one' part in'10,000 of the risk of being killed in an auto accident and that the authors consider -
even this to be a pessimistic estimate.
Perhaps you will wonder l
. why others.did not tell you this.
I doubt.very much that one could
(
rp find today any responsible nuclear specialist who, 'from personal knowledge, actually believes that the supreme accident. described t
I in the Brookhaven report is a physical possibility for a reactor j
t
[
such as the Bodega. Bay plant.
I believe the supporting documenta-i.
f tion (TID 14844) for the AEC Reactor Siting Criteria,10 CFR 100, would support my contention.
4 Incidentally, from a mechanical design standpoint, very i
l few components in the reactor plant are even subjected to neutron
'(
t 4
processes.
Thus, most of the design is along lines of long j
f established power plant practice, and is. dictated by the forces, temperatures, and ctresses arising from non-nuclear considerations.
(
Excellent examples of the degree to which reactor designs have i
l
[
been tailored to environments involving substantini forces and i
i vibrations are seen in the mobile reactors, such as those on ships and veessis, which must obviously witnatand the oscillations and.
L dynamic forces of storm wave action, underwater concussion, and dockin6 Designing reactors to witnatand shipboard service condi-tions. involves the same. principles as the design of land based reactors to withstand shaking, as by an earthquake.
Such forces
~
' : ?.
~~
~'
~
..-_.a.
s
.(
i i
(
are measured-in terms of the force of gravity, sometimes referred to as simply "g".
A force eqttal to the weight of an object, but-
' operating in any direction, is. termed a force' of one "g".
The 1906 San Andreas earthquake involved maximum forces in certain areas of about 0.3 g, but at Bodega only about 0.2 g.
The Nuclear I
Ship Savannah, which visited San Francisco some time ago, was
?
designed to withstand g forces of wave Oction of about 0.3 s.
U. S.
t Naval design criteria for heavy equipment require it to withstand' i
}
forces in excess of 6 3 from underwater explosions.. It is noted r
that planned application of nuclear reactors in the national space.
program will obviously involve designs certified for the high accelerations, several times g, and 'ribrations during rocket launch.
These requirements would naturally extend to all. portions of.the reactor plants, including instruments and controls.
In the Bodega i
Bay reactor, for example, normal service conditions for the j
i i
control elements involve mechanical forces twenty times that of gravity; as you might expect, they are correspondingly sturdy, and j
weigh over 200 pounds apiece.
In large measure, it is simply.
I sound mechanical and structural engineering practice rather than nuclear engineering which plays the key role here.
It is not the nature of reactors.that shaking per se, as -
by an earthquake, causes them to increase in power,- get out of control, or " sets them off" as if they were bombs in a flimsy harness.
The potential harm to reactors from earthquakes is related to structural matters--that a vital mechanical part may be broken,, nun,m w4wgwup,4,g gggw unu m.g.gp,s.m.gf
{;
j )
+
.?
6 h
leading to loss-of-coolant and subsequent slow heating of fuel to the extreme temperatures needed for release of fission products, i
Earthquakes are uncommon, and so I cannot relate to you an exten-i sive body of experience with earthquakes, but w* can and do design to resist earthquake forces, and experience-with such earthquakes as
-l we have had gives no reason to doubt that our designs are proper, f
1 he Hanford reactors have experienced a modest earthquake; I
l operation was not affected in any way, although some sensitive-1
' nstruments were noted to vibrate.
Our reactor in Japan is in an i
i j
j earthquake-prone area and is equipped with some special instruments f
4
[
to measure earthquake responses.
Two modest earthquakes-have been 1
experienced since plant construction.
Neither caused any damage, I
and instrument respo.nses were essentially as predicted.
I y
j Our reactors at Vallecitos are about 8 miles from the
[
Hayward fault, 1 3/4 miles from the Sunol fault, and.1 mile from J
j the Williams fault.
Some mild earthquakes have been experienced i
l at Vallecitos.
None caused damage of any kind.
With reactors, the earthquake problem is a structural one.
he practices we follow do not differ from those one would follow in providing a. conventional boiler of equivalent integrity.
All
(
reactors, even those not in California, are designed with earth-i quakes in mind.
All areas of the USA are subject to earthquakes, the only distinction being frequency of occurrence and size of-earthquakes, As reactor designers, we focus on size of eartbouake, regardless of frequency, because the objective is that any es %-
quake shall not have an adverse safety effect on our equipment, i
i^
regardless of how frequent such earthquakes may be.
We require that q l
(
1 2,i:..
- h==a&
- =- ;.,,,.:
-..,5==w.=;, = =p. +,..,.-wp;:,._,.. ;, w w,?.,,.,.,
n,..
T
%.:...=
n-3, U
4 1
competent external authority. establish and characterize.the maximum expected earthquake, and from this we determine'our design requirement.
We commonly retain structural' design consultants to r
advise us on special features of earthquake-resistant design for the equipment we supply.
Our consultant for the' Bodega Bay plant, J
'J.
A. Blume anti Associates,. assisted in the design of our. reactor in Japan.
J. A. Blume and Associates have an. extraordinary reputa-il tion in this field,'and we feel our confidence in them is well.
'f 4
placed.
j i
]
thdern-day nuclear power plant design includes contain-
. j d,
{
ment safeguards, or provisions to render harmless the consequences of hypothetical accidents of extreme severity.
The containment concept to be applied at the Bodega Bay plant is termed Pressure Suppression Containment, a joint development with the Pacific Gas jq
~
li g
and Electric Company, which we in General Electric consider a j ;
t superior containment system.
One key feature is that it provides jj I
[
a means--quenching in a water pool--to reduce pressure so that I
af ter any presumed breach in the process system the driving force for out-leakage from the containment is reduced.
.A second feature i
is that the containment is encompassed by.a second structure, the reactor building, so that any out-leakage from the containment would be to this, instead of to the outside air.
On the improved safety.
aspects'of the pressure suppression containment concept,-in April, 1962, F. A. Gifford, 1962 Chairman of the Advisory Committee on :
3.:)
+...- y,+.,
,...., q'.Q:f,Q m-+.
ny.77m.y n 7.;* X::~ ;} ~,,..,~.Q 3.;~J.~
.Q
g
.~
(
U
[
Reactor Safeguards, said this to a Congressional Committee, the Joint Committee on Atomic Energy:
"We feel that it has been a-major advance as far.as' engineered features are concerned....".
Dr. Theos J. Thompson, also a member of the ACRS, in the same-
' hearing, said concerning pressure suppression, "It is one of two or three.large breakthroughs that have occurred in the last-two or-
.three years in the field of containment.-..".
" Fission products remain behind in the small inner containment at low pressure.
I believe these views reflect ctudy by the Advisory Committee of the ~
f results of the thorousti dynamic testing of. pressure-suppression-I
-(
[
apparatus performed at Pacific Gas and Electric's facility at Moss
{
Landing. -The Bodega Bay containment design will reflect the per-j f
formance of similar dynamic tests applicable to its> specific arrange-ment and geometry.
So far as I know, the pressure suppression-j arrangement is the only containment system ever to be subjected to t
j dynamic testing; all containments are subjected to static testing, i
i of course.
The pressure suppression containment concept is to be j
applied in three of our plants now entering.the design stage.
They are to be located in India, New Jersey, and New York.
We believe
-l 1
that in plants such as this the possibility of accidents with
?
serious effect on the public is rendered virtually zero, and thus.
-j the risks to people are very small when compared with the wide.
I variety of other risks involved in everyday living...
4 I
4
.,-...-...,~-,.4 n,~,---w ey-y,<~n me e.
3 spryy. geyqr,mym -73;p.9q,prmy m me,-myry,
wn, ~y3 7 _ g e-+
l i
Some may not realize-the extent to.which, in plants of a
this type, a multiplicity of barriers. exists between the external environment and the fission products within the fuel elements; all of'the barriers are specifically designed to be undamaged by the shaking effect of earthquakes, and without taking into account important strength reserves--energy absorbtion by. deformation--
4 which exist to a substantial degree in the materials of plant I
construction.
This multiple barrier system even provides margin
'i.
against movement of portions of the foundation.
For example, l
significant motion of part of the foundation could cause a I
l breach in the wall of the reactor building, but consequences of-i l
this would not be harmful because the air in the.. reactor building-y is itself quite suitable for breathing--people work there--and-thus its release to the environment would be-of no consequence.
-l Further motion of part of the foundation could cause distortion--
[o denting--of the containment, iout this would not impair it.
Even I
4
(
Creater motion, which could perforate the containment, would not ll y
itself comprise a severe accident'because the containment itself
}
contains only air.
Accident possibilities only begin with foundatior movements which would cause an opening in the reactor vessel or the process piping system within the containment.
Release to the atmosphere of the water and steam in the reactor would occur in' such a case, but this would not be of truly serious concern from the standpoint of public safety because the amount of radioactive mater-ials in the water is limited,.and it is noted that release from the '
.)
1
,.e,7__. m e # 9.y.,,,,,my,g g.m m y y
.y.m g
mr g
i e
reactor of its water and steam would shut down the nuclear chain reaction, regardless of action of the control rods.
The serious accident potential relates in this case to overheating of the reactor fuel from heat generated within it by fission products, as distinguished from generation of. heat by interaction of neutrons
[
with fissionable materials.
Such fission product heating is only i
j-a few percent of the normal reactor power, and it diminishes with time; but fission product decay heat is nevertheless sufficient in 1
time (from 30 minutes to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) to melt the fuel unless some
{
t means of heat removal are applied.
Design of the plant inclidas l
standby cooling facilities to do just this, using pumps and piping independent from the normal process systems.
Only if one presumes i
this standby cooling equipment to become inoperative and in f
conjunction with failure of the containment and process' system, do
+
l the necessary conditions exist for substantial release of fission
(
products to the atmosphere.
If substantial reactor system and containments failure is presumed to have occurred, the rush of water and steam out of the system would be completed in a minute or I
less.
On the other hand, the decay heat available is only suffi-cient to start melting of some of the fuel more than ten minutes f
later.
Thus when the fission products begin to be in a mobile form, there is no great driving force available to push them out to a tmosphere.
The safety achieved in modern day nuclear power plants involves not only reactor designers and operators, but a govern-l 1
mental regulatory and licensing process of great rigor, including
,' l
', m,,,._ -.,, _
...-.._...~_.......f,ZX._.....,.{~} ]
s
,1
~
e e
L
+
review and approval by government agencies of plant sites and plant.
designs before major construction proceeds, continued inspection during construction, review again on completion of the plant, and I
continued inspection and surveillance during its operation' there-after.
Important' documents on licensing proceedings'are made publir as are all pertinent AEC regulations.
i
[
'l AEC regulations, supplemented.by those of state.or other
,f agencies where applicable, also. control the day to day emission'~of b
n
,t radioactive waste products to ' air and water to make sure these do j
L not exceed levels adverse to the public interest.. These regulations
]
are based on years of scientific study of the effects of these f
added increments of radiation to man's environment,. including 'the mechanisms by which these materials might be re-concentrated, such j
as by marine life.
Operation of boiling-water reactor plants continues to l
1 show that the waste outputs tend to be less than one percent of that from major AEC centers, such as the Hanford plant,.which are used by some as norms for comparison, and from which the releases have been j
L under continuing surveillance and study for many years, not'only
- 1 L
1
?
by representatives of the AEC but also by the state agencies involved, to make sure that these practices are.,not prejudicial to public health or commerce.
' As a measure of ' comparison,.we might mention studies within General Electric on the details of waste experience at the
?
l e.
+
e6
,= no-ausse. s *menee _
t I..)t P
1 dT ea9MF J' W
' the' y *,-,
- 69De ePQ
-Opfirx @
gpv $$ty 1
- pgm -M f
$M
- "ge* M KJ, e$f* Jg
L a.
...w...
1 j.
l-Dresden reactor plant.
When.we compare actual release rates with those permitted in the AEC licenses,. for example, the emissions of
?j gases are found to be sbout one-third of one percent (1/300) of license limits.- For liquid wastes, it may be enough to say that the daily discharge at Hanford is ten times the yearly discharge at;Dreaden.
l Not many seem to know that all common things are radio-s f
active to one degree or another, and that the.world has always been this way.
People are radioactive because of the naturally f
i
{
occurring potassium, hydrogen, carbon,.and radium in foods.
Salad
{
oil and sugar are radioactive because of the radioactive carbon l
and hydrogen in them.
he air is radioactive because of the radon.
l
)
gas in it.
Radioactive cosmic rays continually come from the sky.
l 2e earth beneath us and the materials' our homes -are built from l
,[
are radioactive.
As a consequence of this, each person absorbs a certain amount of' radiation each year, just in the process of 1
ordinary living.
Based on Dresden experience, the neighbor of the plant i
\\
with the highest amount of incremental radiation from its operation received not even one percent more than normal radiation.
i 4
This increment, incidentally, is too small to be measured in the i
environment, and must instead be' estimated on the basis of careful 4
J monitoring of releases.- The same sort of thing may be calculated.
for the extra radiation absorbed by'a person drinking water taken- 0 l
k fA. N em n-w-, **w ag g,y rasjg
,,ggq q.pg;
.p.4 4
,4
.g
I
.1.
.i g.
~~-.c..
... ~.. _.-.;_
m.
4 l.
I s
t from the river downstream of the plant.- This increment turns out to be.002 percent of natural radiation.
Another way to view these radiation exposure increments is to compare them with the variations in natural radiation which occur from place to place.
The radiation increment corresponding to living.near the Dresden plant is about the same as one would i
get by deciding to live at an elevation '100 feet higher than your I
1 l
neighbor, to taking a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> flight in a jet airplane, or to spending a week in the Sierras.
Perhaps more importantly, this I
.I !
radiation exposure increment corresponds to about 10.-percent of j;
}
[
the increment involved in moving your residence between Santa Cruz j
11 and San Jose, and perhaps 2 percent of that for a move between j
~
Richmond and Tomales Bay.
I have not' indicated the direction of 1
i the move in each' case, or indicated which of each of the two loca-1 tions has the higher natural radiation level; to me it would seem pointless for any individual to consider moving his residence on i
the basis of radiation exposure increments of this level, even
'k I
j though the increments so much overshadow those from living near a
?
nuclear power plant.
It would take far more time than is available here to l
provide you with a thorough and complete understanding of all the safety' aspects of modern day. boiling water reactor power plants.
But I' hope that from this brief discussion some important points,
T 1
. ~. e..-.a n.m w.m a ~Q~L-; ~.
H l
. =. m = ;. = :..._ ~ = --; -- = -;..:~.::..
,L}
m 3
r,
/
- i will stick in your mind.
1.
he' General Electric Company has had extensive experience in virtually all phases of the national atomic energy-program and has achieved an extraordinary safety record
+
i throughout:all these endeavors.
This safety achievement is an important part of the reputation we' place at stake
)
in the provision of commercial nuclear products; we l
value this reputation' highly.
2.
The type of reactor plant to be provided at Bodega Bay
_.i
(
l 1s one of great simplicity for which considerable highly successful operating experience is available.
3 The design safety features of the equipment we' provide i
are complemented by containment safety features, the. pres-j sure suppression system developed by Pacific Gas and 1
[
Electric, and by governmental review, licensing, and I
)
j inspection programs.
We consider the aggregate safety 4
s i
l achievement to be of a high level indeed, and that 4
i there is no supportable cause for public concern as to j
i the safety of atomic power stations of this type,.as licensed and inspected by the Atomic Energy. Commission..
4.
Actual experience from operating boiling-water reactor i
plants'shows conclusively that the controlled, day-to-day emi'asion of radioactive materials from these plants is-at levels which are minute compared to.the radiation which has always characterized man's environment, and which are small,when compared with the radiation exposure decisions all of us make every day without giving.these matters.a second thought.,
- ..,- s.
,- w,-w n.,r ~ r ermm r.- y +.-
-e yyy.- c.s y.. ens.e-m m ym4ferep.r,y. n sc..p.y.ru* g
=......;... -. -
t.
(
4 1
7 1
l 4
I t
.{
4 L. H. McEwen Manager, Nuclear Safety Engineering j
Atomic-Power Equipment Department General Electric Company 4
175 curtner Avenue, San Jose, California 1
4
.l l
B.S. in Chemical Engineering, University of Washington,~1944
(
MBA Harvard University, 1948 t
j Employed by General Electric since 1951 1951 - 1955 Reactor Engineer, Hanford 1956 - 1958 Supervisor, Heat Transfer Research, Hanford 1958 - 1959 Manager, Research Planning, Hanford d
i 1960 - 1961 Manager, Fuel Engineering, Hanford 1962 -
Manager, Nuclear Safety Engineering, San Jose Affiliations:
I 1
American Chemical Society i
,American Nuclear Society Atomic Industrial Forum - Reactor' Safety Committee j
1 l
l h
1 E
4 S
x,,,.
q.m,,,.,__...,.,,..,,,.,,,_,,,,.,,,..
.,q
- ~~.-,-,..,,-.