ML19220B698
| ML19220B698 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/17/1979 |
| From: | Bender M, Carbon M, Etherington H Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-1630, NUDOCS 7904270232 | |
| Download: ML19220B698 (15) | |
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M2iiUTES OF THE THREE MILE ISLAriD SUSCGt'MITEE MEETItiG - 1717 H Street -
R30M 1167 - WASHI:4GT0!i, DC 20555 - APRIL 4, 1979 77 The ACRS Three Mile I' land (TMI) Subcommittee met in Washington, DC to begin its review of the recent incident in TMI Unit 2.
The notice of the meeting appeared in the Federal F,egister Vol. 44 tio. 64, Monday, April 2,1979. fio public statements were received, tb requests to make oral stetcrents were received.
Attachments as noted below are included:
A: Agenda B:
Detailed Schedule C: List of Attendees Executive Session (OPEil)
Present: ACRS_
H. Etherington, Chairman C. Michelson, Consultant M. W. Carbon W. R. Stratton, Consultant M. Bender Z. Zudans, Consul tant W. Ke rr J. C. McKinl ey, DFE S. Lawroski R. Muller. ACRS Staff D. W. Moeller M. S. Plesset D. Okrent C. P. Siess The Chairman called themeeting to order at 3:30 p.m., and made an opening statement citing the fact that the meeting would be conducted in accordance with the Federal Adivsory Committees Act and the Government in the Sunshine Act.
He introduced the above ACRS members and consultants, and noted that John McKinley was the Designated Federal Employee.
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The Chairman asked if in view of the just-completed Commission meeting on the same subject, which all had attended, the Subcomittee desired a pre <,entation or would be interested in starting out with questions.
Dr. Okrent felt that a presentation on Item 2, Current Plant Status, would be worthwhile since this had not been covered very completely.
fir. Bender asked that the Staff review alternate scenarios.
Dr. Carbon pointed out that the full Comittee would meet with the Com-missioners the following afternoon and would continue its discussion at 9:00 a.m. the following day (April 5).
Meeting with NRC Staff Key NRC Staff memoers prt:;ent were Edson G. Case and Darrel Eisenht..,
with E. Jordan, N. Moseley, and J. G. Davis in a supporting role.
Mr. Eisenhut pointed out that the existing sequence of events was put together from strip chart recordings in the plant and talking with operators, but not much on conjecture on what actually happened.
As yet there was no Staff position. He indicated the transcript of the Com:nission meeting will be the only record. There are no copies of presentations. The sequence of events will be contained in a bulletin to be issued April 5.
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EJ LJ L U L. L_.D In response to a question from Dr. Siess about the chronology of the event, Mr. Eisenhut observed that several inconsistencies had crept into the list.
It was known that at 7-1/2 minutes into the event the sump pump in the containment was on.
He was not sure when it was off or if this was the only time it came on.
Dr. Okrent asked when water first entered the sump. Mr. Eisenhut indicated water went into the tank until the rupture disc ruptur9d at 15 minutes and he noted this does not correlate with the fact that the sump pump went on at 7-1/2 minutes.
Mr. Bender asked about hydrogen evolution in the pressure vessel and if it occurred in several stages.
Mr. Eisenhut stated he couldn't say but the heat-up transient occurred at 13/4-2 hours into the event, but how much hydrogen was generated or where it went he was not prepared to discuss.
In response to Dr. Carbon's question he assumed the hydrogen came from a metal water reaction but some possibly had also come from radiologic decomposition of water. One hydrogen recombiner was running - the gas was,5out 2%.
Early calculations varied considerably.
The hydrogen bubble is about gone. The system is at 1000 psi pressure and hydrogen solubility at that pressure is high. The hydrogen concentration stayed essentially constant while the bubble was disappearing.81-251
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3 J Dr. Plesset asked if the only path out for the hydrogen was through the pressurizer relief valva.
Mr. Case indicated that was the main route although some could have come out around the centrol rod drives.
Mr. Eisenhut indicated there was no bulk sample available to check on the composition of the gas.
Dr. Okrent felt that that information might be useful enough to warrant an expected exposure of 1 or 2 rems to obtain.
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Mr. Eisenhut pointed out that the sample would have to not contain any liquid to be of value.
He reminded the Subcommittee of the high radiation levels in the auxiliary building.
Dr. Zudans asked about the technology used to get the bubble volume.
Mr. Eisenhut replied that it involved a complicated equation.
Dr. Zudans observed that it migt.i be a good idea to test such an equation at an operational level.
Dr.Zudans asked about the thermocouples.
Mr. Eisenhut explained that there were not thermocouples in each fuel bundle. At 4:30 a.m. April 4 0
0 t'e hottest was 461 F, two more around 413 F and the res. at~mt 328 F even though the bulk coolant temperature was 280 F.
The thermocouples are 0
actually 4 inches above the fuel bundles. The one reading 461 was 0
previously higher but had recently hovered around 460.81-252
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A primary coolant sample had been sent to Bettis for analysis.
(The Staff was impressed with Bettis willingness to take on any task at any hour of the day tc help out). It would be analyzed for fission gases and products from the control rods.
Dr. Lawroski asked about the rate of change of the bubble and asked 4
for speculation on where it went.
Mr. Eisenhut said it was swept out the vent valve in the pressuri::er, via the hot leg.
He felt it probable that no more hydrogen was evolving.
He indicated that slow ramps up and down had been applied to ceasure pressuri. er levels.
He noped additional hydrogen can be discharged this way.
He said the solubility curve was around 1200-1500 cc/kg at 1000 psi.
Temperature had less effect than pressure in reducing hydrogen solubility.
If another bubble is created at lower pressure it is hoped to get rid of it the same way. Mr. Etherington stated that his calculations showed it would take about 5 days for 1500 cubic feet of hydrogen to disappear.
Mr. Eisenhut indicated B&W's calculations indicated the bubble would hit zero earlier.
In response to Dr. Moeller's question on the impact of any NRC interaction, Mr. Case replied that NRC told the licensee to stop pumping water from the industrial waste tanks into the river.
Contact was continuous from fairly early in the event.
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L L-I Dr. Siess asked when senior Metropolitan Edison personnel were first on site. Mr. Davis didn't kr.ow but in response to another question he said an on-site NRC inspector probably would not have been there at 4:00 a.~.
Dr. Stratton asked about radiation. Mr. Eisenhut stated that readings were available from early in the first day.
It was 10 rem /hr at the operating deck and the containment dome climbed from 600 R/hr to 3,-4,000 R/hr early in the day.
The highest was 20,-40,000 R/hr.
Dr. Okrent observed that the containment should isolate on high radiation level.
He asked if during the spike in pressure the containment was isolated.
Mr. Eisenhut replied the spike was at about 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />, containment isolation at 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />. He indicated to Dr. Okrent he would check why the containment did not isolate on high radiation level.
Dr. Okrent observed that the setting may need to be reevaluated.
Outside the dome the radiation levels were 3-4 mr/hr.
(Attenuation 107_
9 10, due to thick, aircraft-crash-proof concrete, and a thick layer of steel. )
In response to Dr. Zudans question re the time o f determination that this was no casual transient, Mr. Eisenhut noted that a general emergency was declared about 7:30 a.m.
A site emergency was declared earlier and earlier yet high activity was noted in the let down line.
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~7-Mr. Case explained to Dr. Okrent that there were 5 full time phone lines between the site and Betnesda as well as a facsimile transmitter.
The chronology was sent oack and forth several times to get concurrence at both ends. Mr. Case noted that NRC has listeners at iridustry working gro ups.
Dr. Okrent suggested pulling additional Staff members and indicated that ACRS might want to send some of its staff.
Mr. Case explained there would be many levels of NRC review.
I&E would determine "who did what", NER would look at B&W plants generically and certainly a group such a:; the one that investigated Brown's Ferry would look to see if NRR and I&E were doing their jobs.
Mr. Eisenhut said he thought r.ot all the damage was done prior to notiff-cation of NRC.
In response to Dr. Plesset's concern about the requirement that a reactor coolant pump always be left on Mr. Eisenhut inoicated they had considered things like minor vibration.
Even B&" recommended keeping at least one reactor coolant pump running.
Dr. Carbon asked if total loss of feed water, including auxiliary feed water was a Design Basis Accident.
Mr. Eisenhut stated it depends on what emergency feedwater is available.
'ut, he observed, it didn't include losing reactor cooling and ECCS at the same time.
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-a-Mr. Michelson asked if any containment or purge valves were open at the start of the incident, "r. Eisenhut said he believed not.
The one inch line off the pressurizer has a controllable valve.
Re the feed and bleed performed during the incident, it was felt that the filters on the let down may have been plugged earlier and some relief crobably came through the relief valve in the let down system.
CURRENT STATUS (4: 30 a.m., 4 April) 1.
Heat removal through reactor coolant pump 1 A through A steam generator, through bypass valve in A steam generator to the condensor.
2.
Degassing flow through pressurizer vent line secured at about 4 a.m.,
4 April.
3.
One recomb. er operating (25 Hydrogen), one on standby.
4.
The let down line comes from one of cold legs before the main pump.
5.
Main RCP operating, bypass on main feedwater pump. All RCPs operable.
6.
No machinery problems (no list of operating equipna't available at the meeting).
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Data:
Pressurizer pressure
- 1066 psi 235 feet Level 550 Temp 2830 Inlet A 2910 Inlet B Calculated let down flow 15 gp.a.
Level nress Secondary Side Steam Generator A 91 ", 30 psi B
83% 24-27 psi 1.97%
Containment Hydrogen Pressurizer Heaters all operable 80-850F Containment Temp HPI pumps all operable Mr. Etherington asked if all offsite power were lost, are things in good Mr. Eisenhut shape, recognizing that the diesels won't operate the RCPs?
Dr. Siess asked if the plant could be put into a natural felt they were.
circulation mode.
Mr. Eisenhur believed it could.
He agreed to have that discussed more the next day.
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ur. ta., ro s r 1 asrea about instrument loss.
One pressurizer level indicator (cut of 3) was out.
One flow indicator in 3 loop was out.
Mr. Michelson a:ked what would be done if pressurizer heaters were lost.
Mr. Eisenhut agreed to cover that on 5 April, The meeting was adjourned at 5 p.m., because the Staff had to leave.
The discussion would be continued at the full Committee meeting on 9 a.m.
Thursday, 5 April.
A transcript was kept and is available through Ace Federal Reporters, 415 Second Street, N. E., Washington, D. C. 20002 (202-347-3700).
81 258
A l l AL, rvien s n Federal Resister / Vol. 44. No. 64 / Monday. Apnl 2.19"'9 / Notices 115'2 --
The agenda for subject meeting shall Advisory panel to the National Council Da'ed March :s.19m 1
be as follows:
s adim on the Arts ar nounced in the Federal 5""? *f
- Ca'=
g.eidy* AN (1s s Register Vol. 44. No. 50-Tuesday. March P A 75-12:8 Fad N "" **l M P m. unG1 the conclusion of business 13,1979 has been amended to include an a@3 C%E 1m" open sessicn for the public.The The Subcommittee may meet in Executf n meetings will be held as announced on Sessien. with any of its censdtants who may March 31,1979. from 8:30 a.m. to 7:00 Advisory Com.nittee on Reactor
. be present. to emplore and excnange their
. mary opens regadg canus M pn. Apnl1.1979, from 8.30 as to 7.30 Safegua es.Swbcommittee on pr Consideration of Class 9 Accidents; shodd be censidered dunng the taeting and pm. Apnl 2.1979, fro:n 8.30 a m. to 6.00 Meet!n; Postponed to formdate a report and reccc=endationa P m, and Aan! 3.1979. from 800 as to to the fdl Comnuttu.
P 6.00 ps, in room 1422. 2401 E St N.W.,
The ACRS Subcommittee on At the conclaion onhe Eucudu Senico, Washingten. D.C. A portion of this Consideratica of Class-9 Accidents has the Mcomn d hear prnwanons by meeting milbe open to tie public en postponed indefinitely the meeting stheduled to be held ou April 4.1979 in
[efCS eIpc e
a son April 3.1979, from 3.00 pm to 4.00 p.m.
The topic of discussion will be Dance Washington. D.C. Notice of this meeting 'Compa::y, et al. and their consultants.
Touring Program Guidelmes, was published on March :0.1979 (44 FR pertment to this review.The Subcomittee may thes caucus to determine whether the The remaining sessions of this 16955).
matters identmed h t'.e irJtial session have meeting on March 31,19N. from 8.30 Dated: Ma-ch :3.19 9.
been adequately covered.
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an to 7.00 p m.. Apnl 1.1979. frcm 8.30 s w 3. a.2, do om ci ed a.m. to 7:30 p.m.. April 2.1979, from 8:30 s,,wy er e, ca.-. -
sessions for the purpose of exploring matters p x mac s n;w w ess **I a.m. to 6.00 pn. and Apnl 3.1979, frcs - sea coca tsso as-as A4 tavolving prepnetary information. I have E:30 as to 3.00 ps and 4:00 pa to JV; deterr.ined. in :cordance with Subsection 6.00 p.m. are for the purpose of Panel to(d) of Pub. L 92-463. that, should such teview discussion, evaluation. and sessioes be required. it is necessary to close Advisory Commetee on Kea sr these sessicas to protect prepnetary recommendation on applications for safeguares, succommittee on the Three informnon (5 U.S.C. 55:b(c)(4)).
financial assistance under the NaticnalMile island Nuclear Station, Unit 2; Meeting Further information regarding topics Foundation on the Arts and the The ACRS Subcommittee on the Three to be discussed,whether the meeting Hu:nanities Act of 1955, as amended.
Mile Island Nuclear Station. Unit 2. will has been cancelled or rescheduled, the includmg discussion of infor=ation hold a meeting on Apn! 4.1979 in Room Chairman'a ruling on requests for the i
given in confidence to the agency by IC46.1717 H St. NW, Washington. DC opportunity to present oral statements grant applicants. In accordance mth the 20555 to discuss an incident which and the time allotted therefor can be determination'of the Chair =an occurred at this station on March :8.
obtained by a prepaid telephone call to published in the Federal Register March 1979 resulting in release of primary the Designated Federal Empicyee for 17.19 7. these sessions will be closed tocoolant into the containment and the this meeting. Mr. Ragnwald Muller.
the public pursuant to subsections (c)(4), declaration of a general emergency by (telephone 202/634-1413) between 8.15 (6) and 9(b) of section 55:b of Title 5. the operators at this station.
an and 5.00 pm. EST.
United States Code.
'Ib meeting notice is being published Background information concerning Further infor=ation with reference to on an emergency basis (less than 15 this nuclear station can be fouad in this meeting can be obtained from Mr.
days prior notice) since this unexpected documents on file and available far
}ohn H. C! ark. Advisory Co==ittee incident is a matter which warrants Manasement Officer. National c
de g
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Government Publications Section. Stete C. 0 6, or cad (20 )
7 meet ng prior to Apnl 5.1979 is required I.ibra.y of Pennsylvania.Educataon nonwealth and Walnut March 28.1979.
to review the plant status and the i
actions taken to Ilmit the risk to the er ceat amt 61 ognuer.i xarmal public.
Dated: March 3.19"9.
o e
to mor m sa=4 ca.
p w 3 ee-o rsw s-so.ra aas,,
In accordance with the procedures 3""7 'M C"***
e,ap.o coct ts t.es as outlined in the Federal Register on A Da* = n;d = **8*=1 October 4,1978. (43 FR 45928) cral or suo con tsm written statements may be presented by NUCLEAR REGut.ATORY members of the public, recordings will be permitted only during those portions COMMISNON of the meeting when a transcript is bein8 OFFICE OF MANAGEMENT AND Advisory Committee on Reactor kept. and questions may be asked only SUDGET Safeguards. Procedares Subcommittee:
by members of the Subcom=11 tee,its Agency Forms Und'er Review Meeting Pcstponed consultants. and Staff. Persons desiring The April 4.1979 meeting of the ACRS to make oral statements should notify
Background
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Procedures Subcommittee, scheduled to the Designated Federal E=ployee as far When executive departments and be held in Wa.shington. DC. has been in advance as practicable so that agenciet propose p ib!2c use forms, vpptcpriate arrange:nents can be made
'[,thetp 80 postponed indefinitely. Notice of this to allow the necessary time during the e
meeting was published on March :0, meeting for such statements.
and Budget (ONG) reviews and acts on 1979 (44 FR 16986),
those requirements under the Federal 81~259
ATTACHMENT B_
m ato C,
UNITED STATES
+
y s- / [,g NUCLEAR GEGULATORY CC,l.1 MISSION 3 p.QL I 8
ADVISORY COf.if.ilTTEE ON REACTOR SAFEGUARDS
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j WASHINGTON, D. C. 20555 April 2,1979 H. Etherington, Chairman Three Mile Island Nuclear Station Subcommittee SCHEDULE FOR TriREE MILE ISLAND SUBCOMMITTEE MEETING, APRIL 4,1979 The ACRS Subcommittee cognizant of the Three Mile Island Nuclear Station will meet on April 4,1979 in Room 1046, 1717 H Street, N.W., Washington, DC to review the recent incident at Unit 2.
The tentative schedule for the meeting is:
2:00 p.m.
Chairman's opening remarks and Executive Session (OPEN) 2:15 p.m.
Meeting with the NRC Staff and Metropolitan Edison Company (OPEN) 1.
Chronology of the incident comencine with the feedwater system upset 2.
Current plant status 3.
Generic aspects 4.
Health aspects 5.
Recovery plans It is expected that the GC Staff or representatives of the licensee will present summary information on each of these topics and details will be developed by questions from Subcommittee members and consultants.
Topics 'may be added to or deleted from the above schedule as appropriate.
It is anticipated that the following ACRS members and consultants will attend this meeting:
H. Etherington M. plcsset C. Michelson, consulant M. Bender D. Okrent W. Stratton, cor,sul tant W. Kerr C. Siess
- 2. Zudans, consul tant S. Lawroski N. palladino, consultant D. Moeller A
i j ho ec cc:
See Attached List v
f nch tb.1 81~2GO
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H. Etherington April 2,1979 cc: ACRS Me.nbers R. F. Fraley M. W. Libarkin T. G. McCreless R. Muller L. Gossick S. Hanauer L. Crocker H. Silver H. Denton R. Boyd S. Levine D. Vassallo V. Stello B. Grimes D. Eisenhut R. Mattson H. Thornburg N. Moseley 1
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ATTACHMENT C Fi Attendees _
NRC H.
ACRS E. Case H. Etherington, Chairman D. Eisenhut M. Carbon E. Jordan M. Bender N. Moseley W. Kerr J. G. Davis S. Lawroski D. B. Vassallo D. Moeller L. P. Crocker M. Plesset J. Crooks D. Okrent J. Norberg C. Siess B. J. Snyder C. Michelson, Consultant R. Martin W. Stratton, Consultant Z. Zudans, Consultant PUBLIC J. C. McKinley, Staff R. Muller, Staff P. Sei f fert, Doub, Purcell T. G. McCreless J. Mattimoe, SMUD M. Libarkin B. Washburn, DOE, NPDD R. Savio T. L. Fiedler, KNR J. H. Bickel H. Hamada, TEPC0 A. Bates J. Col by, Fl a. Power Corp.
D. Johnson M. A. Carrso, NUS Corp.
P. Boehnert R. H. Lo gue, PEC0 F. Graham, AIF J Fialku, Wash. Star W. Bellanti, American Nuc. Ins.
- d. Blake, Shaw, Pittman C. Negin, Int. Energy Assoc.
L. D. Kenworthy, Int. Energy Assoc.
N. Gillen, House Small Business Subcommittee on Energy T. Timinns, Westinghouse Hoffmeister, FR of Germany T. Himmel, Min. of the Interior, FRG H. C. Huang, Westinghousa B. Kiplink, Toronto Star Stnd.
P: Parshley, House Interior Cmte.
I. Aoki, Mitsubishi T. Kitamusa, MHI P. M. Abraham, Duke Power Michael McGarpy, DeBevoise & Liberman Nichol as Reynolds, DeBevoise & Liberman R. E. Martin, Duquesne Light Co.
J. Carey, Duquesne Light Co.
R. Schmidt, IAEA J. Kraener, Fried, Frank 81-262
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PUBLIC - Cont'd R. Borsum, B&W N. Sili rl ey, GE M. D. Tower VEPC0 P. Morris, Scandpower, Inc.
J. H. Rubin, Burns & Roe, Inc.
K.0ta, The Kansai Electric Power Co.
D. B. Waters, Carolina 1ower & Light G. F. Stiennon, Minist.y Elon-Affairs Bel gium H. A. Dopchie, Vincotte-Belgium H. Dresse, Electrobel-Belgium M. Feinsilber, AP S. Sarisuhn, American Nuclear Energy Council
.