ML20094A741
| ML20094A741 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 11/01/1984 |
| From: | Zebroski E ELECTRIC POWER RESEARCH INSTITUTE, GENERAL PUBLIC UTILITIES CORP. |
| To: | |
| Shared Package | |
| ML20094A683 | List: |
| References | |
| SP, NUDOCS 8411060519 | |
| Download: ML20094A741 (15) | |
Text
r-of 28 ps'ig at 1350 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.13675e-4 months <br /> on 28 March,- the previous day.
I con-cluded_instantly without further discussion that the spike was i
caused by hydrogen ignition in the containment, that'therefore s
the mushiness in the primary system had to be due to the pres-ence of hydrogen gas loose in the primary-system, that the hy-drogen was from a zircalloy-water reaction and that we had to get the hydrogen out.
The spike looked like those we used to calculate for hypothetical hydrogen ignition in containment ex-
. cept it came down faster.
Containment-pressure was subatmospheric which could be due to having used up oxygen by burning hydrogen.
I asked the young engineer for another pres-sure reading and he pointed to the wide range trace at the bot-tom of the same chart.
I asked for building temperature traces.
They were confirmatory.
I asked for xerox copies and stepped back into the shift supervisor's office where Tom Crimmins was with several others and told him that there had been hydrogen ignition in contain-ment, that there was a hydrogen bubble in the primary system, ti at we had to measure it and that we had a fighting chance to get it out because hydrogen " diffuses like a shot."
The great sense of urgency to measure the size of the bubble derived not only from wanting to confirm or refute its presence but also to find out whether it was growing, to find out whether it was then large enough to interfere with reactor coolant pump opera-tion on which core cooling then depended, and to estimate whether the core could be uncovered by bubble growth if 8 1060519 e y
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depressurization; occurred by failure of pressurizer heaters or a critical seal or valve.
While the term bubble was used then, as it is now, we knew it could be several or many bubbles in a number of places.
One aspect of the events just described may need explana-tion at this point before resuming the account of what happened
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next.
Sardonic doubt was once exhibited in my presence as to how the meaning of the' spike could be rapidly apparent among the many things going on.
I think the question of why I recog-nized it whereas others apparently hadn't deserves considera-tion, and the answer, I believe, is at least three-fold.
First, on the 29th, puzzles had been accumulating all evening.
The primary system acted as though steam was in it cutside the pressurizer but temperatures were too low.
The waste gas tanks were full but we did not know why.
Lots of ra-diation was loose in containment, but we did not know what the fuel damage was like.
And we felt a great urgency to get an-swers.
The visual image of the recorder trace resembled graphs of calculated hydrogen pressure spikes I had seen before and that image was the trigger which made all the then-known pieces of the puzzle fall in place.
This kind of thinking is intu-itive, not analytical in the pedestrian sense.
But, I believe it is a well recognized psychological process.
The second factor is background.
Although I am a licensed nuclear engineer, my degree is in chemical engineering and I worked in that field and chemistry for five years during which m..
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e I had personalfexperience with both the potential for and the actuality.of. fires and explosions.
During the early years of nuclear reactor design we were especially sensitive to the pos-
- sibility that metals such as aluminum, stainless steel and zircalloy used as fuel cladding could react with water at high temperatures to produce hydrogen and destroy the cladding.
Later on, accident analyses such as those for TMI, included consideration of these reactions as well as hydrogen production in containment by radiolysis and by reaction of spray water with aluminum and zinc.
Those familiar with these analyses knew the aluminum source was over-estimated and radiolysis was slow.
Most operators and many engineers did not have this kind of background then and so probably were not as sensitive to the possible meaning of a pressure spike.
The third factor is stress.
Although I am not an expert in this area, I know from experience that except for those who freeze, acute stress makes one especially alert to start with but dulls analytical and physical capabilities fast.
Stress is especially high if one can't figure out what is going on.
The operators and most others present upon my arrival in the con-trol room had been under high stress for long periods.
Some of them had not slept much, if at all, in about two days.
We, on the other hand, while under high stress, were relatively fresh, better able to interpret the more obscure clues such as the spike.
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I Given these three factors, I do'not find it surprising at h
all that the situation developed the way it did.
I don't find it surprising in such a complex, confusing, unprecedented and on-going situation that it took a combination of circumstances al.d a fresh look to recognize the significance of what may at first have appeared to be a spurious instrument reading among hundreds of other readings and alarms.and plant control prob--
lems.
I say this because I have a recollection, imprecise as to time, that mention was made among many other things in my presence at some point on March 29 of a containment pressure recorder spike said to be a spurious indication:
e.g.,
caused by a voltage anomaly in instrumentation.
I recall being skep-tical of that explanation.
In all the discussions, however, no one had exhibited or implied in my presence any recognition of the significance of the containment pressure spike.
Nor did I pause to reflect on my skepticism at the time and, indeed, until the graph of the spike was shown to me which prompted the reaction described above.
And this leads back to the story.
I knew from personal experience that under high stress one tends to lock-on to a perception of reality which, even if the best available, may be wrong.
I had been trained to recognize and handle such situa-tions.
So even though we felt great pressure to act, Tom Crimmins and I forced ourselves to take the time to review the facts and test the logic of the hypothesis about the spike and related matters.
When the hypothesis held up, I called someone,.
and asked for the best man available to help us.
Shortly af-terward at about 2330 Mr. Jim Moore, an experienced GPU engi-neer arrived.
The three of us sat in the shift supervisor's office trying to figure out how to measure bubble size.
- Finally, after what seemed a long time but probably was not, Jim Moore' i
said, "Boyle's law ought to work" and I recall. thinking, per-haps saying almost before he had' finished, "And the pressurizer is the piston."
Boyle's Law states that, other things being equal, the volume of a perfect gas is inversely proportional to absolute pressure.
Although other things were not equal and a
hydrogen is not quite a perfect gas, it was obvious that the volume of a bubble, if there was one in the primary system, could be measured approximately by measuring the difference in system pressure caused by a given difference in pressurizer level.
I asked Joe Logan, the TMI-2 Superintendent, to change level to get about a 100 psi pressure differential.
Operations said they had some data like that from the previous day.
I asked that it be "QA'd," that is, verified before we used it and then commandeered the open telephone line to Lynchburg from a B&W engineer and made two urgent, highest priority requests of Don Nitti and Jim Taylor whom I found at the other end:
First:
What is the free volume under the head of the reactor pressure vessel down to the top of the nozzles?
N. -.
Second:
Make refined calculations of bubble size, using pressure, temperature and pressurizer liquid volume change information we would give them, taking account of gas solubility and anything else pertinent assuming the gas is hydrogen.
Jim Moore and I then made calculations of bubble size indepen-dently and_got approximately the same answer.
When we cor-rected each other we had a bubble size of 1568 cubic feet at 875 psia from data.taken at 1245 on 29 March.
My calculations are time marked 0235 on 30 March.
Subsequent estimates from data taken about 0330 on 30 March gave a bubble volume of about 1100 cubic feet at 875 psia.
We had not yet gotten proof of the interpretation of the pressure spike but the hypothesis had been greatly strengthened.
At about 0325 hours0.00376 days <br />0.0903 hours <br />5.373677e-4 weeks <br />1.236625e-4 months <br /> B&W called back to report the free volume in the reactor vessel down to the outlet nozzles was 1129 cubic feet.
Even though the first bubble volume calculat-ed of 1568 cubic feet was larger than this, and the second about equal, it was clear the core wasn't uncovered.
Questions to Operations indicated amperage and vibration were normal for the one primary pump which was running.
So there wasn't enough hydrogen to interfere with main pump operation at then current system pressure.
But there was enough so that depressurization could uncover the core and defeat core cooling by methods then being used...
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Shortly before-0400 after talking to B&W, I started to calculate-the amount of zirconium-cladding in the core which' must h' ave burned to produce enough hydrogen for global ignition in containment and for.a hydrogen bubble of the size measured.
I. stopped before completion _because of the' press of urgent mat-ters.and since rough numbers and mental corrections indicated a large part or all the zirconium had burned.
I didn't necessar-ily believe all of it had,4 but it was clear now that the core was-very seriously damaged..That was what we needed to know at-that time.
At about 0400 after discussions with Crimmins and Moore, I recommended to Joe Logan that he start venting the pressurizer to containment while holding the pressure at the then current level of about 970 psig with pressurizer sprays and heaters on as much as possible.
I also asked that analyses of the hydro-gen and oxygen content of the containment atmosphere be obtained as soon as possible.
The venting was aimed at remov-ing hydrogen from the primary system by steam stripping dis-solved hydrogen from the hydrogen rich water brought to the pressurizer by the sprays on the' assumption that the hydrogen in the bubble would " diffuse like a shot" and replace that stripped and so the bubble would gradually disappear.
Venting from the pressurizer was started later on 30 March.
Containment atmosphere sampling done between 0518 and 0638 of 31 March showed residual hydrogen of 1.7% and oxygen of 16.3% by volume clearly supporting the hypothesis of a hydrogen.. _ _.
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ignition..The normal concentration of oxygen in air is about 21% and hydrogen is essentially absent.
At 2338 of 1 April B&W i
reported by telephone that at 1550 that day the bubble in the primary system had disappeared according to volume calculations and noise measurements.
This was confirmed by a graph sent to me and received at 0044-of 2 April.
The disappearance of the bubble was consistent with the initial interpretation of the spike.
As more information was accumulated over the next days and weeks, the initial interpretation was demonstrated without doubt to be correct.
I find it inconceivable that if anyone had known hydrogen was present in containment and had ignited, they would have concealed that knowledge from peers or managers and that the on-site technical support team would not have been told of it.
No motive for concealment by those involved existed since too much was at stake including, perhaps, their lives.
Also, I find it inconceivable on other grounds that the real significance of the pressure spike was deliberately con-cealed by an exercise of duplicity or dishonesty.
I know many of the people involved and have for years.
They simply would not have done such a thing.
And when I say that I include Mr.
Kuhns, Mr. Dieckamp, Mr. Arnold and all of those managers and engineers with whom I worked during the accident.
In the course of working with Mr. Dieckamp during the accident, my high regard for his honesty, managerial ability and patience, which has certainly been tested under very.
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4 difficult circumstances during the past five years, was recon-
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firmed.
'I might add that Mr. Dieckamp gave a great deal of personal' attention'to what was going on during the TMI-2 acci-
' dent.
He, for example', called me directly several times near midnight of Friday, 30 March when he was concerned, as we all-
-were, about.th'e potential ~for another buildup of hydrogen con-
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centration in'the containment 2due to' venting the; primary system
-and duefto.the slow radiolyticLdecomposition of water in the bottom of the containment building.
To recapitulate, no recognition of or even speculation about the s'ignificance of the pressure spike was exprecccd or implied in all of the extensive'and intensive communications I heard or.was party-to from early morning of.28 March until the spike's significance was recognized at-about 2300 on 29 March as I have described.
These communications were with both se-nior and. junior engineers, operators and' managers, probably more than 50 in all.
Nor did I hear about any such prior rec-ognition from the hundreds of people I dealt with subsequently while on duty at TMI for nearly a month.
Furthermore, the peo-ple I know and dealt with would not have deliberately concealed such knowledge.
And I state that judgement with emphasis and-without qualification.
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<.,vl UNITED STATES OF AMERICA C0:;rO '.u. ' S W '"
NUCLEAR REGULATORY COMMISSION "3M BEFO'RE THE' ATOMIC SAFETY AND LICENSING BOARD
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In the: Matter of
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METROPOLITAN EDISON COMPANY
)
Docket No. 50-289 SP-
)
(Restart-Management Remand)
(Three Mile Island Nuclear
)
Station, Unit No. 1)
)
TESTIMONY OF E.
L.
ZEBROSKI My name is Edwin L.
Zebroski.
My= current position is Chief Nuclear Scientist at the Energy Study Center, a part of the Electric Power Research Institute (EPRI) in Palo Alto, California. EPRI is the research arm of the electric utility industry. Prior to joining EPRI, I held various design and de-velopment positions in Stanford Research. Institute, (Physics
. Department), and in the General Electric Company, Research Lab-oratory, and in the Nuclear Energy Division.
My training in-cludes degrees in Science from the University of Chicago and the University of California.
I am a registered Professional Engineer, and a member of the National Academy of Engineering.
I have authored or co-authored over 120 technical publications and patents relating to the basic and applied science of nucle-ar= energy.
A major area of my specialization during the period 1965-1976 was the behavior of nuclear fuel under various operating conditions, including transients and accidents.
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4 The purpose of'my testimony is to. cover three. main points, based on my personal observations and involvement as a member of the Industry. Advisory Group, convened at Three Mile Island in the1early days following'the accident:
l.
~The; extent to which there was a rapid learning curve-evident in the days immediately after the acci-dent, in respect to organizing, and interpreting, the
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large volume of. plant data, and in sorting out dif-ferent views and speculation as to thefextent and na-ture of the damage to the reactor, by focusing on generation of hydrogen as illustrative of this learn-ing curve.
2.
The extent to which related uncertainties re-
.mained for months after the accident, reflecting the limited general state of knowledge of severe core accidents at that time.
3.
The extent and nature of the involvement of Mr.
Herman Dieckamp in the activities and technical dis-cussions of the Industry Advisory Group during the period of my observation.
At the time of the TMI-2 accident, I was Director of the Nuclear Systems and Materials Department at EPRI, which con-ducts research and development programs aimed at improved life-time, reliability, and cost-effectiveness of components, fuels, i
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~(Mr. Dieckamp was gener-
- and systemsEof" Nuclear Power, Plants.
I ally aware ~of these programs through his participation in prior
_ years in-two-of the advisory committees which serve EPRI.)' At a Research Advisory Committee meeting in Sco'ttsdale, Arizona, Dr.,S.
Bartnoff of GPU reported to the Committee on March-29 and again on-the morning of March 30, that an incident had oc-curred:at-TMI-2.
Later-in the morning of March 30, Mr.
Culler, the Presidentfof EPRI, reported to the same meeting on a phone call'from.Mr. Dieckamp which indicated that the situa-tion had deteriorated ~ relative to the perceptions on the previ-ous day.and that technical support help :from EPRI was needed.
Mr. Culler agreed to send technical assistance to TMI, ini-tially consisting of Mr. Milton Levenson, then Director of the Nuclear Division at EPRI, and myself.
Mr. Dieckamp outlined' four basic tasks which needed technical support; I was asked to undertake the first task which was Core Damage Assessment.
After a conference call on March 30 with Mr. Robert Keaten of GPU, I traveled to TMI, arriving on the morning of March 31.
Office and conference space was made available at the National Guard Armory adjacent to the Harrisburg airport.
An initial meeting to review the situation was organized and the technical
- review discussion was led by Mr. Dieckamp on the afternoon of March-31.
Sometime~during March 31, I became aware of the pressure spike which' occurred shortly before 2:00 p.m. on March 28, 1979.
I' remained at TMI intermittencly for the next four weeks, serving as co-leader of the Industry Advisory Group
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which was assembled to provide calculations, and evaluation of options for-maintaining control and safety of the' reactor sys-
- tem.
My investigative. efforts on core damage at TMI during the
- initial days following the accident centered on several ques-tions: namely,-(1) the postulated hazard from the gas bubble in the reactor, (2) the possible extent of' core damage, and (3) possible means for' removing the gas bubble.
The gas bubble evident in the reactor was postulated to be-potentially subject to ignition and explosion creating a sense of immedia :e potential for catastrophe.
This potential appar-ently was first postulated about March 30th, and was reported in the national media with banner headlines.
Various people from national laboratories discussed the explosive potential.
The President's Science Advisor was reported to have commented that New York City and Philadelphia might be exposed to severe radiation if the bubble were to explode.
A helicopter re-portedly was dispatched to bring sacks of oxygen-absorbing chemicals-(like sodium hyposulfite, a chemical used in photog-raphy).
In the telephone call with Mr. Robert Keaten of GPU on March 30 (mentioned earlier) he noted that he had become aware of a gas bubble in the reactor vessel but did not know its source or its full composition.
He hypothesized that it might contain some-air, from air dissolved in the borated water used to assure safe nuclear shutdown of the reactor.
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I stated to Mr. Keaten my belief rhat oxygen'could not be present in the reactor vessel and that no explosion was possi-ble. :I repeated this-position later in meetings with NRC peo-ple on. site (Stello, Vollmer, and Mattson).during the period March 31 to Aprill2, quoting the extensive literature on this
' subject dating to the 1950's and 1960's.
The basic scientific information was that the presence of even small amounts of hy-
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drogen suppressed the effect of radiation on water.
(In the absence of excess hydrogen, radiation acting on water can pro-duce h'ydrogen and oxygen in a volume ratio of 2 to 1, which is an explosive mixture.)
Apparently none of the staffs or the officials of the var-ious government agencies involved were aware that since the mid-1950's, hydrogen was routinely used in all pressurized water reactors -- both Navy and civilian power -- to prevent the formation of oxygen-hydrogen mixtures by radiolysis.
I urged the NRC representatives to make telephone calls to the national laboratories (Brookhaven, Argonne, and Oak Ridge) where the scientific and test work had been done to check out this information.
This work was widely published in technical papers, and covered in textbooks on nuclear engineering.
By about April 2nd or 3rd, the NRC decided that the evi-dence against the possibility of a hydrogen-oxygen explosion was indeed unquestionable, and the bubble was disappearing.
3-This was announced publicly, with the comment that previous >
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'concernsJof possible explosion were due to overly conservative Jealculations. -(It was later evident that the earlier ~ inquiries-
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'toLthe national laboratories did not' indicate that hydrogen was present.in-the reactor vessel.)
During the same days-I was also continuing my efforts to estimate the extent of core damage.
The prevailing state of knowledge on possible reactor core damage as of 1979 was.the analysis in the report. Wash-1400.
This' report, and the related NRC calculations'used in. licensing, postulated-that if cooling water was lost, the fuel would' fail (distort and leak) due to high temperature, and that'the~ reactor core would then procee'd to. melt down with extensive spread of the bulk of the-radioac-tive elements in the fuel-(up to 70% of the total).
The infor-mation available to me March 30 through April 4 did not corre-spond to such a degree of severity.
The observations available March 30 and 31, (including the pressure spike and the indica-tions of high levels of gaseous radioactive elements, but only small-amounts of iodine and cesium) was that a significant' fraction of the fuel was certainly perforated, releasing most of the rare gases.
The apparent evidence that only a small fraction of the iodine and cesium were released was consistent with perforation of fuel cladding, but not necessarily gross-disruption or melting of fuel.
If major core damage were present, a large fraction (up to 70%) of the iodine and cesium would be expected to be volatilized -- according to the pre-vailing calculations accepted by the NRC.,
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The pressure' spike was evidence of the probable presenc'e 1
1 of enough. hydrogen to burn, but of itself'was not evidence of i
how much had been produced..Small amounts of hydro' gen -"as low as 4% in air,'are known to be capable of ignition ---which would result in a pressure pulse, even if there was simply
-burning rather than explosion.
I was aware that hydrogen gas
~
from-gas" cylinders is routinely used to provide a small-amount
- of hydrogen dissolved in the reactor coolant.
As noted earli-er, the dissolved hydrogen is used to prevent the decomposition of water by radiation (radiolysis)', which would otherwise form.
There was an evident need-to determine whether some hydrogen cylinders or piping might have leaked hy-drogen-into the containment, which then could be ignited when a y
relay or motor was actuated or started.
Another possible source of hydrogen was-recognized to be from the reaction.of zirconium with. steam at high temperatures.
This was.also plausible but did not of itself necessarily imply more extensive f I damage than just perforation from. localized overheating.
Los
_1 zed overheating alone could cause clad bal-looning and rupture, with or without the added effect of oxida-tion of zirconium.
One of the major technical surprises of the subsequent in-vestigations of the TMI accident has been the low extent of mo-7
-bility of iodine and cesium, despite what we now know to be major core damage, with oxidation of a large part of the.
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cladding.
On the' basis'of the licending analyses prevalent at the time of'TMI, major core damage shohld have been accompanied
~
by the release of large fractions of iodine and cesium-(up to
.70% of: total; inventory) to the primary.systemi and from there U
to the containment building air, and to any leakage paths to-the auxiliary building.
It is now known scientifically (althoughnot'[etfullyacceptedforregulatory. purposes'),-but was not-known or accepted then, that iodine and cesium, under
.c conditions prevailing in a PWR losi-of-coolant accident, have a very strong affinity for water.
The relatively large amounts
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(over 5%) which are now believed to have escaped from the fuel-at TMI-2, have remained almost entirely in the water.
o The small amount of iodine that did escape to the air (a small fraction'of 1%) was readily= detectible in the containment building and'the auxiliary building.
Had the postulated amounts of iodine been released, much larger emissions of io-dine to the containment, and via leakage paths to the auxiliary building, would have been expected.
In the absence of such ob-
.servations, the expectation that core damage was limited to leakage or perforation of some fuel was plausible.
If the fuel were only perforated, then it would still be possible to remove it and replace it using conventional underwater mechanical han-dling equipment.
A small degree of, fuel perforation s
(" leakers") is often present 1E the normal periodic refueling operations.
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f The-question of how much hydrogen was evolved was the. key to determining whether the core damage was limited to perfora-
.tlon or wh' ether there'had been more extensive or even severe disruption of.the core structure.
The-first solid evidence'of
- the amount of. hydrogen: produced cameffrom the analysis of gas-
-samples-taken.from the containment building on March 31 at 0600.
These'showed significant' oxygen 1 depletion (4.4%-to 5.2%
-below the normal'value in air, respectively).
This corresponds to extensive reaction of zirconium (later calculated-to be.45 to'52% of.the' core inventory).
However, at the time, these re-sults'were questioned.
Eight more gas samples were taken on
, April 1 and April 2.
'These showed~substantially smaller oxygen depletion (average value of 2.3%, but with a wide scatter, some samples showing normal oxygen levels or~ higher).
Later samples have confirmed that the initial values from the samples of March 31 are most likely to be valid.
(There is an apparent possibility that in-leakage of air to the gas samples caused the error and scatter.in the April 1-2 samples.)
Even with 50% cladding oxidation, the preservation of much of the core structure was judged tocbe possible.
This assumed
.that the; oxidation of the zirconium cladding produced a layer of oxide, but leaving a metal tube intact under the oxide.
(Somewhat analogous to rusted iron pipe with an average of half of the iron still intact.)
The near-normal readings on thermocouples in the core region also seemed to indicate that the core structure was mostly intact.
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AfterLthe situat' ion.at TMI:had been; stabilized, late in p
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- April,w1979ffthejEPRI Board ~of. Directors.autho'rized EPRI to set' 2,
j 7 ;f up an investigatiion team to assess the' facts, causes, and les-
- sons learnedifrom^the accident.
-t This-led to the organizing of the Nuclear. Safety Analysis
' Center-(NSAC)iat EPRILin.May,.1979, for which I was named the~
Director.
In.the next few months, a total of 80 technical peo--
pie were enlisted-in.the investigation for aLtotal of 12-
~
man-years o@ effort.
Th'is' effort. produced a1 report (NSAC-1)'
issued Julp, 1975 on the-sequence of events,-with1 supplements
' in succeeding months.
A. final report incl,uding :the supplements Man 4.othed' investigations were was distributed in-March 1980.
r proceeding which involve'd exhaustive. interviews with plant per-a t
sonnel.
.These interviews apparently,were finding a consider-l able range of conflicting recollections'and perceptions.
It was decided that the NSAC study should rely on the detailed analysis of/ instrument records and to avoid reliance on recol-1 lections or# interpretations by plant personnel.
Accordingly, we did not interview any of the plant person-nel.
(We did have full support and help from GPU and plant I"
personnel in finding and copying any instrument records and logs.
This eventually amounted to over 50.000 pages of
! records ) ~.
Some months later, in Palo Alto, analysis of the instru-ment records brought out awareness (in USAC) of an apparent
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thermallshockito the reactor core,: possibly from a rise of water' level in the core atLaboutJ7:47 a.m'.'on March 28.
The-nuclear.. instruments also showed a change in readings.which could be interpreted as' relocation ~of fuel by slumping or col-
~1 apse.of fuel' rods:previously'embrittled by oxidation of the
- cladding.
(I was. aware of the results'of two' incidents in which experimental fuel was' operated without adequate cooling and which resul'ted in fragmentation of the fuel rods.)
The NSAC. analysis reported in NSAC-1 suggested that 1
roughly the upper.two-thirds of the. core had been uncovered and subsequently overheated.
Given that about 50*A of the total' zirconium was converted to oxide, the local oxidation in the upper part of the core would ha"e to be,near 100%.
The fuel-cladding in this region would be almost-completely converted to e
a ceramic oxide.
The sudden cooling of a hot brittle ceramic can result in fragmentation.
The likelihood that core struc-ture was preserved in this region was then recognized to be small.
From this emerged the hypothesis published in NSAC-1 report, that a region of the core shaped like an inverted bell, reaching to within about 3 to 5 feet of the bottom of the core, was most likely fragmented into a rubble bed.
(This analysis was confirmed conclusively only in July-August 1982, when a TV camera was lowered into the reactor core region.)
During the period that I was at TMI, Mr. Dieckamp contin-ued to keep in touch with me and Mr. Levenson and to s---,
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. participate in the technical discussiens.after..the initial'
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meet 1ngs:of the3 Industry Advisory Group'(IAG)', to'which I.re
.ferred earlier. There was also an operating support' group'at-TMI;1ed.by Mr.' William S': Lee (of Duke Power) ~ for a: time and then'later by Mr. Byron Lee (of Commonwealth Edison Co.).
Mr.
1Levenson and I. met with this group dailyfto review our findings and recommendations.
Mr. Dieckamp participated' actively'in
.these. discussions.- There were also daily meetings with the principal NRC representatives-(led by.Mr.=. Victor Stello)'to discuss our findings'and-recommendations, also with active par--
ticipation by Mr. Dieckamp.
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Y=1 RELAIED CC '7PCMCENCE DCUE.5C UNITED STATES OF AMERICA
'hw NUCLEAR REGULATORY COMMISSION.
84 gl -5 P2:24 BEFORE THE ATOMIC SAFETY AND LICENSING BOARD hf$CJS f?y aa In the Matter of
)-
)
Docket No. 50-289 METROPOLITAN EDISON COMPANY
)
(Restart-Management Phase)
(Three Mile Island Nuclear
)
Station, Unit No. 1)
)
CERTIFICATE OF SERVICE I hereby certify that copies of Testimony of Herman M.
Dieckamp, Testimony of William W.
Lowe, Testimony of Thomas Leroy Van Witbeck and Testimony of E. L.
Zebroski, dated November 1, 1984, were served on those persons on the attached Service List by deposit in the United States mail, postage pre-paid, this 1st day of November, 1984.
V. hah, Erne'st L.
Blake, Jr.,
P.C.
Counsel for Licensee DATED: November 1, 1984 1
m
-o-UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter
)
)
METROPOLITAN EDISON COMPANY
)
Docket No. 50-289 SP
)
(Restart Remand on Management)
(Three Mile Island Nuclear
)
Station,-Unit No. 1)
)
e SERVICE LIST Nunzio J. Palladino, Chairman Administrative Judge U.S. Nuclear Regulatory Commission John U. Luck Was',iington, D. C,. '20555 s
Atomic Safety & Licensing Appeal Board Thomas M. Roberts, Commissioner U.S. Nuclear Regulatory Commission U.S. Nuclear' Regulatory Commission Washington, D.C.
20555 Washington, D.C.
20555 Administrative Judge James K. Asselstine, Commissioner Christine N. Kohl U.S. Nuclear Regulatory Commission Atomic Safety & Licensing Appeal Washington, D.C.
20555 Board U.S. Nuclear Regulatory Commission Frederick Bernthal, Commissioner Washington, D.C.
20555 U.S. Nuclear Regulatory Commission Washington, D.C.
'20555 Administrative Judge Ivan W. Smith, Chairman Lando W.
Zeck, Jr., Commissioner Atomic Safety & Licensing Board U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Washington, D.C.
20555 Administrative Judge Administrative Judge Gary J. Edles, Cha'rman Sheldon J. Wolfe Atomic Safety & Licensing Appeal Atomic Safety & Licensing Board U.S. -Nuclear Regulatory Commission ]
Board U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Washington, D.C.
20555
.h.
t.
Administrative Judge Mr. Henry D. Hukill Gustave A. Linenberger, Jr.
Vice President Atomic Safety & Licensing Board GPU Nuclear Corporation U.S. Nuclear Regulatory Commission P.O. Box 480 Washington, D.C.
20555 Middletown, PA 17057
-Docketing and Service Section (3)
Mr. and Mrs. Norman Aamodt Office of the Secretary R.D.
5 i
U.S. Nuclear Regulatory Commission Coatesville, PA 19320 Washington, D.C.
20555 Ms. Louise Bradford Atomic Safety & Licensing Board TMI ALERT Panel 1011 Green Street U.S. Nuclear Regulatory Commission Haytisburg, PA 17102 Washington, D.C.
20555 Joanne Doroshow, Esquire Atomic Safety & Licensing Appeal The Cnristic Institute Board Panel 1324 North Capitol Street U.S. Nuclear Regulatory Commission Washington, D.C.
20002 Washington, D.C.
20555 Lynne Bernabei, Esq.
Gover me t Accountability Jack R.
Goldberg, Esq. (4)
Office of the Executive Legal
.555 Connecticut Avenue t'uh ear Pagblatory Commission as
.g n,
069'
, rt,9 Washington, D.C.
20555 Ellyn R.
Weiss, Esq.
Harmon, Weiss & Jordan Thomas Y.
Au, Esq.
2001 S Street, N.W.,
Suite 430 Office of Chief Counsel Washington, D.C.
20009 Department of Environmental Resources Michael F. McBride, Esq.
505 Executive House LeBoeuf, Lamb, Leiby & MacRae P.O. Box 2357 1333 New Hampshire Avenue, N.W.
Harrisburg, PA 17120 Suite 1100 Washington, D.C.
20036 William T. Russell Michael W.
Maupin, Esq.
Deputy Director, Division Hunton & Williams of Human Factors Safety 707 East Main Street Office Of NRR P.O. Box 1535 Mail Stop AR5200 Richmond, VA 23212 U.S. NRC Washington, D.C.
20555
_ - - -.