ML19308B886
| ML19308B886 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/31/1979 |
| From: | Creitz W, Herbein J METROPOLITAN EDISON CO. |
| To: | |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001170495 | |
| Download: ML19308B886 (15) | |
Text
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O METROPOLITAN EDISON NEWS BRIEFING Harch 31, 1979 American Legion Hall, Middletown Val ter Creitz, president Met-Ed John G. Herbein, vice president for generation Met-Ed CO 8001170 1
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Walter Creit::
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e Ladies S gentlemen, I'm Walter Creitz, President of Stetropolitan Edison Company.
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We sre here today for several reasons, one of which is to bring you up to date on hat has happened at Three Mile Island since our briefing yesterday.
We -elcome the NRC participation by bringing in senior staff people to work with our engineers in order to get on with the Three Mile Island #2 problem.
We particularly welcome Harold Denton whose press conference suggestion for a cc:rdinated source of information.
I think that this makes a lot of sense and
'm sure you will appreciate it too.
The NRC is the regulatory body.
They are the licensed source.
They are the ones that grant us our license and it see:s to make a lot of sense for them to be providing you with updated information regirding Three Mile Isand #2.
We are in close contact with them on a continuous b2 sis and we'll be providing our information to them.
Because of this, we have no further scheduled press conferences at this time.
We understand that the NRC has 1 press conference scheduled for 12:30 at the Borough Council Chambers.
At the end of this press conference, we will distribute a statement covering what we are talking about today and in the future we w enta available i. -he Capitol News Service and as previously, our office at the Hershey News Center will continue to be open.
You have their phone number.
I'll repeat it, 533
'35.
Periodic statements will be issued by us at that time. At this time, we w:uld like to give you the update on Three Mile Island #2.
Jack lierbein, Vice President of Generation is with us again, Jack lierbein.
Jack Herbein:
Thani ycu.
Through the evening, we've continued to vent the pressurizer of the primtry coolant system to the reactor building in order to reduce the size of the ;1s bubble that is contained over top of the uranium fuel in the reactor pressure vessel.
Initial indications are that that has been successful.
It l
l appetrs that the gas bubble has been reduced in size. One of the concerns that
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we hai during the venting is the build up of hydrogen in the reactor building.
Because of this concern, we discontinued venting for approximately two and a half I
-a-4 hours during the evening while we analyzed a sample of the react:r building f.
atmosphere in order to determine what the hydrogen concentration as.
The results of that measurement indicate that the percentage of hydr:;es concentration
- was at 1.7 percent.
Relative to an explosive mixture, that cc:pa es to between 4 and 6 percent when you get into the explosive region.
So, we, f:r the initial venting, don't appear to have a problem with achieving explosive nixture in the reactor building. Additionally, we've taken a reactor coolant simple and had it analyzed for eFF uct activity which,we did find,indi:: ting that there had been fuel failure.
lie did, however, find there was no tranium in the sample that was analy:ed. No uranium or fuel was found in the sa.cle of the r.c c. n ' - t water that circulates through the reactor fuel.
Ife are for alizi g our organi:ation and procedures and, of course, are interfaced with.'.e various assistance that are coming frca all parts of the country to lend us a hand with
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the tough job.we have ahead.
Presently, we are making-up to the ~:o ated water storage tank which is a supply of injection water that we used to ficod the core following the trip early on h'ednesday morning.
rtin is pre.-iding boric acid to replenish that tank.
I understand that approximately 30,:.'3 gallons have been added since yesterday to that tank.
So, it stands ready in an emergency, if the stable condition we have now should dete e,.t: be injected into the reactor core to provide the core cooling necessary. With regard to the releases that are taking place from the auxiliary building, they da continue at about the same level we had yesterday.
They are being very carefully monitored by our on-site and off-site teams, which have now been supplemented with additional monitors and technicians.
Again, we find those levels the same as they were yesterday.
lie expect that those releases will continue for -he r.ex: several days.
We are making the effort to find and contain the source cf radioactive gas icakage to the auxiliary building which in turn is being pickei by the ventilation system andexhaustedthroughtl[e'plantstack.
To da e, we have
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found that there may be a difficulty with the waste gas compressor or with f
a leak in piping system.
We believe this may be a part of the reason that the gas continues to escape into the auxiliary building. This is a pretty significant effort.
I think our people have done a fine job.
We are getting.
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a lot of help now.
I know there has been concernp'about conflicting information that we may have appeared to put out in the initial phases of the incident.
I'd like to clarify that.
We intended to tell the press and, of course, the country, to the best of our ability, what we thought existed at the time we were reporting to you.
I know that I had said previously that we thought we at this time would be on decay heat system cooling.
Of course, we are not.
Continuing in a stable condition while we get a bett'er understanding of this bubble over the core. This is the first time, I guess, that anything of this magnitude has occurred.
We think that it is prudent to go step by step.
While k
certainly the picture is different today than it was two days when I reported to you.
(Explanation and plea to the press crowd concerning orderly conductiveness of the press conference.)
Question:
Mr. lierbein, could you please explain to us in simple terms, step-by-step, how you will be able to bring this plant to a cold shut-down and when you now anticipate that will occur?
{terbein-The time duration is strictly an estimate.
It could be several days or it could be longer than that. The step-by-step procedure involves a continued venting from the pressurizer out into the reactor building and of course, a continual monitoring for the hydrogen huild-up in the reactor building.
Then subsequent calculations to determine on a daily basis the size of the gas bunble.
Once that gas bubble has been reduced in size to where it's no longer a danger of vapor binding the reactor coolant pumps when we lower pressure, or i
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when it is no longer in danger of possiily going down and preventing f1:w up f
threugh :le fuel assemblies, we will then be in a position to lower system pressure :: the point that we can shift over to our decay heat cooling system.
A that p: int, we will further cool. the : ore to the some hundred degrees and 50 cr c 0 ~ :s. that we consider to be the cold shut-down conditions.
Ques-ic n :
In lip:-en's terms, Mr. Herbein, is the :risis over and is there a potential of a hydr:sen explosion?
Herbeir :
I perse:1.'y think that the crisis is over, if you want to refer to it ts that.
Is there i potential of a hydrogen explcsion? I think that that potential exis s, b:- I think it is exceptionally ninimal.
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Ques-icr :
Hss there ':een any type of explosien in -he plant since the first accident took place:
Herbein_:
I received word that,. I believe, on inursday at approximately 1400, there was
- tsa-a pressure.ipike to 30 lbs.
It was accenpanied with an explosive sound and the spray stem did initiate.
I have n:t personally looked into to all the ranificati:.s of that particular inciden.
It did, however, alert us :c the 1
fact -ha: -he possibility of hydrogen generation in the containment was present and as a re sult of that, we initiated s eps to check out the recombiner system hich xc.:1f in fact eliminate the explosive hydrogen concentration in the event that it we:3 to get close to the 4 o 6 percent number that I mentioned. That syste: his been in the initial stages of check-out since yesterday.
Question:
Yesterday, :tr. Denton said that he expec:ed or hoped that the emmissions of gas s
-S-would be stopped today, in the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
No you say that you expect
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those emmissions to continue for the next several days. h'hy?
lierbein:
h' ell, I certainly, I certainly don,'t disagree _ with Mr. lenton's statements.
Certainly yesterday, I had hoped that by today the gas release would be terminated.
It is exceptionally difficult to lock at all the possible sources of gas release to that vent to gain an understanding :f the exposure involved in verifying the possible source and then once that is done, going in and and =anage taking steps to isolate it.
h'e've got to monitor 3our,:ersonnel exposure-key consideration.
Question:
48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> ago, you stood over at flershey and told us that everything was okay and that not to worry folks.......
Question is that were you, your corporation, the nuclear industry il)-repaired to handle something of this
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nature when 'the regulations don't prepare to handle sorething of this nature and if not, how do.......................
Creit::
I think that we're into something that is a differen: isIIgame than we had expected.
I don't think that I've seen anything that indicates that we are not prepared to handle what we've found ourselves in.o!ved in.
I think the l
Nuclear Regulatory Commission has responded.
I think
~.at the industry has responded. Our engineers and manufacturers stand resdy to assist us.
And to date we have not given excessive exposure to any tenber of the public.
Ouestion; The fact that you have been able to flush out seme of the bubble already does that mean to say that the bubble is down to a level of the pipes that take I
the coolant in and out?
k' lierbein_:
hhen we initially started the flushing process to rc=ove the bubble, it did l
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ap; ear that :he bubble extended from the head region to the ares just above
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the coolant pipes.
It now does cppear that that bubble are.2 has been reduced in 3i:e.
I don't have an exact dimension, but it is perha 3 two-thirds the si:n that it was yesterday and now we've got more water ab:te the core up in the region of the (interrupted)
O.:e s t ion _:
And the fuel is all underneath?
- ierbein:
T..it is true.
^.:e st ion :
p Wo:1d you recaVitulate for me how many redundancy cooling syste s are built into this reactor and how many have failed or how many are stil holding up?
He:tein:
We'*., we'll go through the number first of all and none of the=, let me say, f
oA fai'.ed.
There's the normal reactW coolant system with the circulating pumps
-hi:h we are using now to remove the decay heat from the c:re.
In addition to th:, there are three high-uressure injection pumps.
None f those have failed.
~ hey stand ready to inject water from the borated water st:: age tanks as I ne.-ioned.
In addition, there are two low-pressure injection pumps. They also s:s-d ready should we depressurize the systen.. They are icwgressure high volume p_.:s.
Finally, there is a static systo, the core-flood tank system, which water s:t-ds ready to inject 4should the pressu.T go below 700 lbs.
Now in addition, al; those pu ps are backed up by diesel ' generators to prote-:t us from any power loss to the reactor site.
C ;e s tion -
'#nst is this continued gas venting mean to the people who are livint directly
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in, the area?
Hef:ein:
s The gas venting that is taking place in the reactor building is not being released in:o the environment. The kinds of gas that we a. ' seein; 2: the
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plant ven: come fr:: the auxiliary building complex and, we believe c.):he
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gas vent header system which actually collects radioactive gas i.. the support s.
- ems a-i :orpresses (interrupted)
C... s t i on:
Iaw much radica::ivity is getting out?
ferbein:
The degree cf radicactivity that is being released is the same tha:.e've seen for the :15: two days.
The IcVels that we are obtaining at the site boundary L-sn.avertre off continue :o oe 3 :c 4 to 5 millirem per hour. Now we have seen cc:.isional
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c.e spikes thi: are the result of the wind gusts that do go up to la er ;5 millire=5 per hour i dose.
Those are intermittent and they only 1;_!: a matter of minutes.
Question:
t Could you give ur the range of options we~ have to get rid of that b:Ycle rind final;y assess the possibility of danger.....?
Herbein:
I'm not real;y prepared to go through a technical dissertation.
I :ar. say that the most effective 2nd the best way to vent it, we believe 'as..........believe, is the me-hcd e are using, deg ion by the pressuri:er vent s,< stem into the reac::: building.
h'e believe that that is the best of the op i:ns a.ailable.
5 Question:
h' hen you.ere building this system's plant, designing them and ever;-:.ing, did you e.er have an? kind of sec$rios or any kind of rehears Is c: say thin ~g in your m:nd th:: what is actually taking place might happen? Or is this a l
whole new ballgame?
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Herbein:
Cer:ainly the precedures to initiate the core cooling systems hid I have just I
-S-described, have been in existence for sc:e time and have teen thora:ghly rehearsei and cur understood by all the eperators.
Perhs s the sirgie ding tht: we :ay ne: have anticipated is the buildup of -he gas bd:ble
- ser the uranium fue'.
- r
- es t ion -
It the dIys right before the first accident on Wednesday, were you aware of a:y' type of problems in Unit 27 Herbein:
V:en you ta k about roblems, I'm not sure what you mean. We were aware
-i the need for se:e corrective naintenance on plant cc:ponents h:t, that always e:ists. Tne Nuclear Regulatory Co=issi:n had iddntified some improve:ents 2.it were required f:: our protection system, but they also had do:e thit on a nu ber af other rei: tors in the U.S. : day. There were not unusual pro'olems c-Unit ; that we had identified?
l Cr.es tion:
Er. cany pe ple are inside the building? Are they all ycur people! and X"nat are dey doing?
Just wa :hing dials or what?
F -be:n:
7:e peop;e f.n the bui; ding are not all Me:ropolitan Edise: people. We 've g: seni:$ consultan 3.
We've got Nuclear Regulatory Co=ission people that a e present.
They are reviewing the operating procedures before they a e c
sel r.: nally executed and in addition providing adviYe and ceuidfor each step tilt we n.tke.
Final'y, k'e are looking a the back-up pro:edures that we wouId i-.end t: fellew if -e lost the reactor coolant pump which is currently rC.oving :.eL; from tht core.
C_ stion:
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Ab:ut ha. cany people would that involve!
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9 Herbein:
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I ou;d say in the control room complex, approximately 3) to 35.
Cues-i: :
I jus: $1nt to ask you to clarify.something.. As.to where the hydrogen
-is thi exploded? Was it in the bubb1'e? Was it in the other building?
K15 it i: the container? And what are che probabilities of it happening again?
Herbein-The hydr: gen that exploded, we believe, was outside the :ontainer.
It was'in
-he rea: or building.
We are not certain it was an explosion. There is a p:ssi'ri.ity that there was one. That hydrogen, we feel, was emmitted from
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the radi:litic decomposition of water in the presence of gamma rays.
Cue s t i -- -
Is is it possible that the plant is so damaged that they'd never be able
- star: up again?
And where.................................. Unit I and 2 fuel pentrators?
He:Sein:
The p;ar.: is damaged.
The core is certainly sever 61y daniged.
I don ' t co the coing personal:7 believe that the plant is damagedA: hat it can't start up again.
C':vions*y, we have a big job ahead of us to decontiminate and restore the iith r'egard to the replacement energy, we do be'.ong to the Pennsylvania, Jersey, ;aryland Power Pool and naturally the power to cur customers will be provided by the member utilities.
Questi an -
List night, Mr. Den.un said that it would days before anything would be done tovernicht>
- the ;'.an: to affect the bubble.
This corning, you say that^the bubble has reduced in size. Would you explain those differences?
Herbein:
I guess :'should qualiff my statements.
Initial calculations appear to us to l
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a a
W hive reduced the size of the bubble. We have not conferred with the Nuclear f
Esplatory Commission to have a reverification of our cal:ulations.
C';e s tion :
l 5 :,.something deliberately was done overnight to physically reduce the size I
ci the bubble?
I Herbein:
i A-J we did that with the full knowledge and concurrence of the Nuclear f
Rep.:latory Commission.
C:estion:
a rid this happen last night after Mr. Denten held the news conference?
4 Ferbein:
I'm really not aware.
Cf;es t io_n :
F.1ve any workers been exposed to excessive lev 61s of radistion?
Ferb ein:
Yes, we've had to date 4 overexposures and I'd like to pu that into pers, ective.
The allowable limit in a cuarter is 3 regh We've actually given three of the workers between 3.0 and 3.5 re I think the fourth w:rker received in the neighborhood of a rer[
So, we had exceeded the cuarterly exposure limit for the employees.
However, the annual exposure lini of 5 rem has not been exceeded for anyone to date to the best of my k-W. ed ge.
Question:
lyou think.]
I sounds like you have initiatrd a procedure that^will get rid of the hydrogen bu':bl e.
Is that correct?
Herbein:
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Thit is correct.
- .,a,..-
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n Question:
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You have ruled ont then for the moment possibl6 other ways to do it.
Mr.
Denton was talking lbsi night ab6ut increasing the pressure that will collapse the bubble and he talked about blowdowns to get rid of the bubble, but you have decided (interrupted by Herbein)
Herbein:
I think you may be describing some of the back-up procedures that we've jointly discussed between NRC and Met-Ed that have to do with action that would be taken in the event that the primary circulating pump was taken out of service.
Question:
Physically, how are you getting the bubble out? Are you decreasing the pressure to let it p down the cooling pipes?
Herbein:
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Actually, we are degassing the bubble by spraying water into the pressurizer.
The gas then comes out a s61ution in the top of the pressurizer and from there through an open,Atke gas then travels into the reactor building.
ven
_uestion:
Q Could you just clarify simply whether you are sayi6g that the possibility of a meltdown is decreasing and is the possibility of an explosion increasing?
Herbein:
Well, I think as we continue bn here, that the possibility of a meltdown is decreasing.
We are getting a better understanding of the physical parameters that we've had, a better understanding of the equipment operability, and the procedures being required to take the plant to
- the cold shut down 2
conditions.
From that standpoint, I think the meltdown possibility is I
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certainly being minimized as we go along.
With regard as to the possibility of hydrogen explosion, as I indicated, the threshold there is 4 percent
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concentration in the reactor building.
We are monitoring that.
Naturally, f
as hydrogen is released to the building and we get closer to the 4 percent the possibility of an explosion increases.
But to insure that we are prepared for that, we've been running our hydrogen recombiner which is a device that will be connected to the reactor buildi6g atmosphere and in turn would recombine the hydrogen and oxygen into the water form and in so Joing, reduces the percent of hydrogen in the reactor building.
Question:
Herbein:
There is not meltdown in progress.
Secundarily, the rods that 455 shut the fission process down, were inserted immediately Wednesday morning when we suffered the loss of the feed pump that led us ultimately into the condition we are in now.
Question:
But, they said a quarter of those were damaged.....
Herbein:
I think the percentage of damage that you are talking about has to do with the number of fuel assemblies in the reactor. This is where the heat is actually produced add that is different from the devices used to shut the heat process off.
There is a possiblity that we have got a very large percentage of the fuel assembly in a damaged condition.
I can't speak to the accuracy at this point of the 15 or 20 percent.
We won't know that for a number of days.
Question:
Herbein:_
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There is a valve on top of the container. The access to that valve presently would be a problem.
There is no remote control on that.
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-13 Q. er-ic: :
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.s. :en.an said ;ut night that the NRC has not decided *=hid is de best c
epn:n to -ne :: Io to the full shut.down and :..at they are pri:g :n ssit a :::ple of dayi : study that and Gill confer wi-h yeu, bn :. hey will make
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the fina1 decisio:.
Have you made a decisien as ::icenvern:n :: go I: this sh= -de. n. e- ?
C: are you concentrating solely :n this hyc:g en and will dec:le _ht-lat er*
r er: t:.n :.
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- . ie :e.zas:.n:2:lon in coping with the.a.ver: en i roc.. e: :.s tal:1a.
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rir step.hich a critical to getting us ready for the : feer :f cptions tit: na r enst :: ;c to the cold shut-down condi:icas.
- l':in.t we are ge:nng ru.... cea:=rence and at least we are c.re:>m. discuss".! sa:...
r o.nn:.5:
- cezs with the 2C and 46.'
I :cntinue to do that.
Ct:er-io: :
- .:: nere is no :na. decision on how it wu..l.:e :ene,.
Her':nn :
.N.e :. a. cens. n :n the method or proceu,ure t....a.
v21. t e uec. : cepressurl:e
.s
- t..e r; s en, snu
- n the reactor coolant pu p and -hen s...n.: : rer :c :.e decay
. cc c i n.g.
h,e have a standard procec,re Ins: er.. :>e Iva:.., t:1e.
nea oc:e c:
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- nt wi I : ave to be reviewed and peryaps ac.,2nec n r:.ev c:. 5::e or ::e cr.n:nict s.u: exist. The point being
- ,.,,.1: a oss :: ::.e rete::r coolant
. c=. :ould ':e a tr:olem in the event that the 10- Oressure ::cli.t s s e:i didn't
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'.e w.1; crobablY want to run the reacnr co lar: T.u=.= 1:id the decay he.a ;ums in pa-a;:e1 for some peiiod of tire 'ref:re we shi - de.: to -he z,-... e.._..... p.
Q:erOn
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Hzve ou ice::1 e: exact 1-what is in that. rues e c ar.rarine,s. o ocrti:as of 1
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'I i:~o:::es. f,.50, de vou know what other decav products ra.v hrie.enten into the J
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pri::ary er s er:ndary ?
ienein:
We have a. 'ur:d t:st anding, at this point, of t:;.e isotopes that are pesent.
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in:. :ha there are isotopes of iodine and cerium.
I can't quo:e de Oc :en:rs:icn in the reactor coolant. We did, a day ago, take so:e reactor co:.an: syste: sarples.
It was 100 r, od con act,'it was only 100 nilliliters, so y u inow se've got quite a bit of fission product activity in de water sys en.
We art not completely familiar with the contents of tha: ps bubble, bu: dron eve yning we see, we believe that the principle conten: :s : tenon 133...
- C ne
- tear --is section of the tape due to =stling of mike and
.c men ra'.iin; c'os er to nike than Mr. Herbein is.)
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