ML19220C733
| ML19220C733 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/09/1979 |
| From: | Gossick L NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | NRC COMMISSION (OCM) |
| References | |
| NUDOCS 7905140110 | |
| Download: ML19220C733 (52) | |
Text
'
NUCLEAF. F.EGULt. TORY CCPEISSION 0FFICE OF INSPECTICN AND ENFCFCEMENT WASHINGTON, D.C.
INCIDENT MESSAGE FORM TO:
Cer=i s sione rs F :.0M:
Lee V. Gassick, EtiT Attached is a prelirainary chronology of NRC actions in connection with TMI that has been prepared in connection with the April 10 hearing.
Copies have been provided OCA, OPE and EDO offices involved.
\\
\\
cc:
Co:=issioners (10) - 2 each CPE (1)
GCA (1)
L. V. Gossick (1)
E. C. Case (2)
-J. G. Davis (2)
SP (1) t'PA (2) 790514011o cATE:
/09n9 Tnig:
1015 C:ntact:
Steve Conver,.?A Y
105 W of ESCLOStiPI 2
iCF.
9 L;0 NRC REACTICN TO THREE MILE ISLAND ACCIDENT CHRCNOLCGY OF EVENTS (FRELIMINARY)
Attached is a chronology of the ccmmunications and actions regarding the notification to NRC of the TMI accident, notifications made by NRC, actions taken and various related cccrunications.
The source for the entries are as shewn, and, except for the entries whose source is shown as OC Tape (telephone conversatiens recorded in the NRC Operations Center in Bethesda), cust be treated as preliminary in nature and subject to later confirmation or clarification.
It must also be noted that not all calls to and from the NRC OC were recorded due to saturation of the cc.- unications system requiring use of telephone lines not reccrded by the twenty channel recorder in the Operations Center.
030
. Cate/ Time Source Activity
'lednesday. " arch 23
_AM 4:00 tiene Incident sequence begins.
6:50 Cperations Center Licensee declares site emergency (OC) tape 7:02 SP Folicwup w/PA Licensee notifies PEMA (Pennsylvania Emergency Management Agency) of site emergency.
7:10 - 7: 45 Region I Licensee attempts to contact Region I.
Duty officer and Dep. Director en route to office when beeper sounds.
7:24 OC tape Licensee declares general emergency.
7: 45 Reg. I Upen cpening switchbcard, Region'I receives message from licensee 7:50 Reg. I Region I contacts TMI control recm; maintains cpen line.
7:55 Reg. I Region I cla-sifies event as a Level 1 severity inc.ident in accordance with Region I incident response plan.
8:00 Reg. I Region I Incident Response Center activated; John Davis, 4Qs., notified by Seyce Grier and also by Public Affairs (Fouchard notified by Region I Public Affairs).
8:05 Varicus John Davis crders Hcs Operatiens Center activated.
Region I State Liaison attempts to centact FA Eureau of Rad.
Health.
8:20 Peg. I Region I centacts incependent measurement van (at Milistone site) and orders it dispatched to TMI site.
105 00M
, ~~
Cate/ Time Source Activity 8:23 OC tape Phcne call frca Weiss and Moseley to Grier; John Davis calls Gossick, who was in conversation with Fouchard.
S:25 Incoming Tel. Log Gossick calls Davis 8:30 Reg. I PA State Police informed that NRC emergency vehicle would be en route.
8:31 OC Tape Moseley notifies Stello &
Eisenhut; Stello says he will send radiological experts to GC 8:32 OC Tape John Davis calls L.V. Gossick, decision made to convene EMT 8:34 OC Tape John Davis calls Centon's office; speaks to Case.
8:36 OC Tape Davis calls Hendrie's office; speaks to Bill.Dorie.
8:40 (approx)
Gossick & Case arrive at Cperations Center 8: 40 OC Tape Mike Wilbur calls Boyce Grier, cbtains technicai information.
8:45 Reg. I Five inspectors (including health physicists) with radiatier, monitoring equipment leave for site.
8:46 OC Tape Davis calls Dorie, asks for Cc m. Gilinsky in Chairman's absence; Gilinsky not in yet.
8:48 OC Tape Dudley Thcmpson notifies Tom Carter, NMSS.
No imSS action required.
8:49 OC Tape Ward notifies J. Davidson, NMSS, to make IAT nctification.
8:50 Reg. I log Licensee calls Reg. I with current status report.
\\os W 03A
f
-4 Date/ Time Source Activity 8:50 Reg. I State Liaison contacts PA Bureau of Rad Health 8:52 OC Tape Davis notifies Comm. Kennedy (First Commissioner contacted)
Davis reports that he, Gessick, Case & Fouchard are manning EMT at 0.C.
Kennedy says he will notify Cc:missioner Gilinsky.
8:56 OC Tape Gossick attempts to reach Gilinsky through Bill Dorie and through Gilinsky's office.
Gossick talks to John Austen and requests that Dorie reach the Chairman.
8:57 OC Tape Davis notifies Commission Ahearne 8:59 OC Tape Bernie Weiss calls DCE Emergency Operations Center 9:00 OC Tape Bill Ward informs Randy Pine (CA).
Randy Pine indicates that she will inform local Cr ;'essmen (Hein: & Schweiker) an. Rep. _.
9:00 Reg. I Second vehicle leaves Region for site (investigator plus inspector); Region I contacts rtAP who has already been notified; two teams organized and standing by.
9:00 Bob Ryan Ryan notified by SP Region I personnel.
Arrives Hqs. OC 9:35am 9:02 GC Tape Weiss rotifies EPA (Floyd Calpin) 9:03 SP notes Joe Fouchard cai>3 Carl Abraham, Reg I Public Aff airs 105 M 09
Date/ Time Scurce Activity 9:10 OC Tape Gossick calls Congressicnal Affairs Office.
Randy Pine infctms Gossick thtt CA had received several inquiries from local Congresimen.
9:10 to 9:30 OCA OCA places call to majority and minority staffs of Heuse of Subccmaittee on Energy and Environment, House subccamittee on Energy and Pcwer and Senate Subccmaittee en Nuclear Regulation as well as Senators Heinz and Schweiker and Representatives Walker and Ertel to adivse of declaration of site emergency at Three Mile Island 9:06 OC Tape Bill Ward informs Ccamunications Branch 9:10 OC Tape Grier calls Moseley to explain technical aspects of incident.
9:11 Incoming Log Gilinsky calls Gossick and Davis 9:16 0C Tape Fouchard notifies CCE Public Affairs Office (Scb Dulin).
AFTER 9:15 AM Other NRC personnel began arriving at Headquarters Operations Center (OC Tapes not yet scanned for times after 9:15 am) 9:15 0C Notifications White House Situatien Room Log contacted 9:27 Incoming Log Defense Civil Preparedness Agency (DCPA) Calls Jce Hecner 10:05 PN79-57 Reg. I response team arrives et site 10:05 Reg. I Reg I contacts EPA Hcs. (also attempts to contact E?A: IIIi 105 M6 03t
f.
Cate/Tice Source Activity 10:05 to 10:10 Reg. I Discussion w/ RAP re ARMS aircraft survey.
ARMS people put on standby 10:15 Reg. I Onsite team informs PA Rad.
Health that they are available for questioning.
i 10:16 Inccming Log Conference call:
All Ccma ;sioners and Cavis 10:20 "P Log Telephone to PA State Rad Health Dept. (Gerust.y not available).
Call returned at 10: 45 (1st liaison established by Hqs) subsequent calls every hour or two, starting about 5:25 pm to discuss status of sampling and monitoring.
10:30 to 11:30 GCA OCA calls principal oversight cormittees (i.'cluding appro-priations subcommittees) and Pennsylvania representatives from vicinity of site to advise of release of radicactive mate rial s.
10:30 Reg. I Reg. I contacts Delaware 10: 40 Reg. I Reg I contacts PA Governcr's action canter 10: 45 Reg. I Reg I contacts NY State Energy Office 10:30 P R#79-54 First Press Release based on Preliminary Notification 10:40 SP Log Press Ccnference (frcm where?)
patched through to PA Rad Health Cept.
105 DM 036 Date/T'me Source Activity 10:53 Inccming Log White House Cuty Officer to Weiss 11:00 Reg I Second Team arrives at site and in centrol room 11:35 Reg I FPA Region III contacted 11:45 Reg I NJ Cept of Energy contacted 11 55 Reg I State of MD, Pcwer Plant Siting council contacted E_d 12:04 Reg. I EPA Region III contacted 12:10 Reg I DOE (Valley Forge Office) contacted 12:30 OCA OCA calls principal oversight team-ttees and PA representa-ti,es regarding latest infor-mation (in response to recuest from Henry Myers for technical information arranged for briefing by Mr. Stello) 1:00 Reg I Third vehicle departs for site 1:00 Reg I Reg I centacts MD Health Dept.
1:01 Inccming Log,
Stello calls Henry Myers 1:12 SP Log SP calls VA Civil Defense 1:30 DOE Logs 00E advance party establishes cc.Trand post at Capitol City Airport 2:15 DOE Logs ARMS heliccpter arrives at site and begins tracking.
2:30 DCE Logs ENL RAP arrives Capitol City Airport; sampling be; ins 2: 45 Reg I State liaisen centacts Governcr's office Ccer.ecticut 105 403 03(o
f
. Cate/ Time Source Activity 3::0 SP Log Freposec NRC Press Release cleared with PA Rad Health Cept 3: 45 PN 79-67 First formal preliminary
. notification report distributed by NRC 4:00 OCA Telephone briefing for Senate Subcommittee on Nuclear Regulation and Senator Heinz 5:00 PR 79-55 Second press release issued 5:15 Reg I NRC mobile lab arrives at site 6:00 Reg I Fourth Reg I vehicle leaves for site 7:55 SP Log Call to PA Rad Health Dept (ARMS data shows count is up, status of 5NL monitoring activities).
6:15 SP Log PA Rad dealth Dept acknowledges receipt of A9MS data and says they are keeping Governor informed.
3: 17 Reg. I Log Reg I notified of decision to send NRR team to site; arrival expected next AM.
8:30 Reg I Fourth vehicle arrives on site 3:30-Reg I NRC, State, RAP Team brief 9: 45 Lt. Governor Scranton 9:00 Region I Log Reg I nocified that Salem providing equipment 9:00 SP Log SP verifies (hcw?) that FAA has not been notified.
10:03 -
11:00 Reg. I Reg I tarticipates in Lt.
Governor's press conference 105 $0 037
f.
Thursdav, "a.+h 29 Ed ll::
(?M) to 12:'O (AM) gI Team briefs Governor Thornburgh 12:15 PR #79-66 Press Release 1:03 SP Leg SP notifies Defense Civil Preparedness Agency and reads press release.
2:00 SP Log SP telephones PA Emergency Management Agency, reads press release 2:10 SP Log SP tries to telephone Health Center for Disease Centrol (Atlanta) (PA radiological Health says they will try again in morning).'
8:30 SP Log SP calls H. Calley, EPA, to read press release and suggests he call Gerusky and offer assistance 9:00 Reg I Two additional vehicles (6 people) dispatched to site 9:30 SP Log Food and Drug Administration calls anc offers to have Saltimore Field Office provide assistance in lcoking at food pathways s
9:30 Commission briefed by Gossick, Eisenhut and Jordan at "H" Street 10:25 PN-79-67A Issued 11:00 SP Log SP tries to contact NY Sureau of Radioicgical Health (cali cc pleted at 12:17 pm) 11:05 SP Leg SP calls NJ Cept. of Health.
11:30 CCA L,dirman Hendrie and NRC staff brief certers of Succommittee on Energy and Environment,
, other ?.em:ers of Congress, and Congressional staff on status of incident.
105 % 9 03B
f Date/ Time Source Activity 11: 45 SP Log SP calls Delaware Rad-Health Dept.
12:00 (Apprcx)
NRR tean (Vollmer +7) arrive cri site; Strasma (Region III Public Affairs) on site Pti 12:05 SP Log SP returns call to Gov. Ray's (Washington) assistant.
12:10 SP Log SP. calls W.VA Rad Health contact 12:15 SP Leg SP calls Va. Radiological Health (call finally completed at 1:15).
12:00 -
1:00 Reg I Vehicles 6 and 7 on site (total IE personnel:
17) 2:15 Reg I Congressional group (Hart, L'dall, 'Heinz, et al) arrive observation center; receive briefing.
2:40 SP Log
$? telephones. Fish and Wildlife Service.
3:00 PN-79-67E Licensee pulls thermolumi-nescent desimeters from 17 fixed positions located within a 15 mile radius of site.
Dosimeters had been in place for three months and had been exposed for about 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> after incident.
Only two dosimeters showed exposures above normal levels.
3:01 SP Log SP briefs (by phone) !'d.
Radiological Health cn status of samples.
3:20 Reg I State liaison contact with Verront 10 5 ifl 4
3"
f.
Cate/ Time Source Activity 3:15 -
6:30 Reg I NRC representatives are called to State Capital to brief Governor and Lt. Governor prior to Governor's 5:C0 p.m.
press Conference.
3:35 SP Log In response to inquiry from Minnesota Rad. Health, SP gives status briefing.
5:55 Reg I Log The Executive Management Team directs the licensee to stop dumping all water.
RI notifies HQ that stopping the dumping will cause backing of water into the Turbine Building.
(Late entry - the licensee has been dumping water to the river -- the water is within TS limits WRT contamination.)
6:00 Log???
PA Rad Health says NRC can make decision on rad water dump without checking further with them.
6:10 Reg I Log Licensee notifies NRC.that he is stopping the discharge 5:30 Reg I Log Griefings provided by Met.
Edison to Senator Schweiker, Congressmen Gooding (York),
Mike McCcrmack; Waller (Lancaster),
Weidler (L.I.,NY) 6:00 PN-678 NRC requests Met. Edison to terminate release ;f slightly contaminated industrial'saste.
Permission to resume release granted at 12:15 am and coordinated with State.
State press release issued.
4: 50 -
7:00 Reg. I "ultiple attempts to reach EPA: III concerning industrial
' caste ct ps; finally centacted at 7:C0 p.m.
105 F42 40
i.
Cate/ Time, Source Activity 6:35 SP Log PA' Rad Health calls back and asks NRC to hold river dump because of Governor's concern.
SP provides update on ARMS data.
7:05 SP Log Offer from DOE Emergency Assistance.
8:30 Reg I Call to Governor's Aide to inform of core damage 8:00 -8:30 SP Log Updated status reports to MD, WVA and US Sureau of Rad.
Health 10:05 SP Log PA Rad Health says "go" if NRC wants to have water dumped.
10:12 Reg I Log Industrial Waste Discharge verified to be off.
Frida-ich 30 y
AM T2:05 Reg I Log EMT asks IE/ site to relay to "et.
Ed that NRC says OK to release industrial waste.
Notify NRC when release cor ences.
2:06 Reg I Log Industrial Waste Tank over-flowing onto ground s
5:35 Reg I Log Fire in Unit One Aux. Building Basement - (picked up frca interccm).
Fire in ventilation system.
8:00 SP Log Status report to EPA 8:20 SP Log Status report to FDA, Bur-of Radiological Health S:30 SP Log Status report to Md. Rad Health S:50 SP Log Call frca FPA requesting status 105 @t3 t;-[
f.
Cate/ Time Scorce Activity 9:00 Reg I Controi reem cersonnel (Unit
- 1) hear announcement tha'.
evacuation in a 10 mile radius around plant has been recommended by NRC.
9:05 Reg. 'I Onsite inspector calls Regien to verify that above was true.
Were told recommendation was not official.
9:25 Reg I Log State notified of release; evacuation rumored; site does not plan to call for evacuation.
9:15 -
10:10 SP Log SP calls PA Civil Defense re potential evacuation 9:50 PN 79-67B Issued 10:00 Reg I Log Scme confusion exists because State evidently has reccmmended evacuation of Middletcwn (Doc.
Collins).
Plant /NRC has not recommended evacuation.
10:25 Reg I Log Ccmmunicaticn Lost with Unit 2 Control recm 10:30 -
10:45 Reg I Log State has advised residents within 10 miles to go inside and shut windows.
NRC position remains:
no evacuation /
unnecessary to take any special precautions.
10:47 Cmsr. Tel. Leg Conference call between Gossick and Commissioners:
decision to send Denton to site.
11:00 Reg. I Unit 1 Centrol Recm beccmes aware that an evacuation was suggested by Governor-ll:"O Cmsr. Tel. Lc; Hendrie and Governor discuss evacuation.
105 MM YA
f :ste/ Time Source Activity 11: 45 Reg I Log Release at 11:09 for about 15 secs.
12:03 Reg I Leg Chairman of NRC reccamends that Governor of PA evacuate 5 mi. radius.
12:07 Reg I Log EPA, Region III advised of evacuation recccmendation.
12:30 Reg I Lag The NRC evacuation recommends-tion is changed or is clarified as follcws:
pregnant women and preschool children in the 5 mi. radius shculd be evacuated.
This recommendation to Gov.
PA - not public.
Dr-Langford of EPA is notified of this change.
1:00 SP Log Another conversation with FDAA re Governor's recommendation for President to call National Security Council meeting at 1:30.
1:15 -
1:30 SP Log Calls to MD, Delaware, NY, NJ VA, W.VA Rad Health regarding Governor's reccmmendation.
1:25 Casr. Tel. Log Hendrie conference at White House folicwed by 1:30 p.m.
NSC meeting.
1:30 Reg I Another vehicle (2 HPs) departs for site.
2:C0
!ics s burg Denton +12 arrive by Gossick Notes helicopter at site; 2:20 fics sburg NRR Cperations Center Gossick Notes established at nearby residence; notifications to President Carter and Go,ernce Thcrnourch.
2:30 Reg I Director and Branch Chief plus 2 H?s dispatchec by heliccpter-e 105 @Hr
. Cate/ Time Scurce Activity (Abcut 3:30 Unverified k'ayne Kerr (OSP) +5 arrive at site to assist IE Health Physics.
By this time, 83 NRC personnel are en site and in vicinity (51 IE, 4 SP, 3 PA, 25 NRR).
6:30 Press Release Press release "no imminent No. 79-67 danger of core melt; technical experts (Denton et al) on site" 8:45 Reg ' Log (Madden) acting as Administrative Officer reports the follcwing:
Trailer, manned by NRR (Denton) and the White House Communications Group is now behind the Observation Center and wired for use.
Additional Trailer by 2145 will be wired with 6 telephones.
Scyce Grier is downtewn in Harrisburg at a Press Conference w/Stello, Centon, Governor Thornburgh.
Air Naticnal Guard Unit at Harrisburg Int. Airport avail-able for assistance.
Saturday. March 31 Date/ Time Source Activity AM TT25 SP Log Coordinating meeting held at Capital City Airport (EPA, DOE, PA Dept. of Environmental Resources, FDA, NRC).
2:50 SP Leg Telephone call frca Eettis, Radiological Assistance Team at Cc mand Post at Capitai City Airport; analytical ecuipment in airport hangar.
6:C0 Reg I Leg Oak Ridge man believes he can use the Lecse Parts Monitoring to tell the size of the bubble in the vessel.
\\o5 W W
16 -
Cate/ Tire Scu ce Activity 5:25 SP Leg Call frca PA Civil Defense; status update.
About 9:00 Public Affairs Center activated at site; limited operation until April 1.
About 8:20 SP Log Trailer moves just cutside plant gate; NRR cperations center in full force.
9:17 SP Log Call frca HEW asking what their role would be if evacua-tion necessary; NRC says PA Civil Defense has lead status update.
9:25 SP Log Call frem CEQ; status report 9:20 SP Log Call from NY Rad Health Bureau; status report.
10:00 SP Log Call frca Defense Civil Preparedness Agency; status report.
E 12:00 SD Log Conversations with FDA-Sureau of 12:30 Radiological Health re supplies of potassium iodine.
2:00 SP Leg PA Rad Health Dept. agrees to refer all calls relating to health matters to NRC.
3:25 Casr. Tel. Log Commission meets in Bethesda at Operations Center.
4:25 Cesr. Tel. Leg Hendrie and Governor confer via telephone en status.
5:00 SP Log NRC infcrmed that Gcvernor, W.
Va. had activated State Radic1cgical Assistance Team.
105 OW 95
. Cate/ Time Source Activity
$_mdav Acril 1 10: 45 PN-67G NRC representative (Stello?)
at facility informed that sabotage attempt would be made during the night.
FBI, PA State Pclice and licensee notified.
1:30 SP Log SP calls DOE Command Center (they do not know where EPA people are); also calls PA Rad. Health; EPA lab is next door but no one is there.
8:13 SP Log SP calls PA Rad Health (00E will collect all data and transmit results to NRC).
Meeting scheduled at 8:30 to set up coordination.
9:36 SP Log Contact established by Lubenau/Vaden at PA Rad. Health offices.
11:00 Reg I Log NRC Personnel on site (65 I&E; 27 NRR; 5 others).
PN-67H NRC establishes 37 TLD stations at distances from 1 to 12 miles from plant.
PN-67H All utilities with an operating B&W reactor are sent an NRC Bulletin to:
(1) provide information on TMI-2 incident (2) require a prompt review of their plant conditions, (3) take action to prevent such an incident.
NRC inspectors are being sent to each licensed E&W reactor to provide increased inspection coverage.
2:15 -
2:27 Reg I Log President Carter is en site in Unit 2 Control Foom.
E: 40 Gossick Notes NRC calls DCE/EOC to request cleanup of AUX Euilding.
General Public Utilities requested help.
105 0$8 4
, I'_mday Acril 2 23 Cate/ Time Source Activity 3:25 Reg I Log Hg requests licensee to send sample of containment air (2330 sarple) to Eettis.
5:50 Reg I Log Phone link drcps out/HQ will try to re-establish conference call.
6:25 Reg I Log Phone link re-established FM RIdnight Gossick notes Denton briefs Governor of PA.
ms W?
47
i 7
-0 3
'N PRELIMINARY DESCRIPTION OF EVENTS AT THE THREE MILE ISLAND 2 FACILITY ACCIDENT The following is a summary of the significant events that occurred at the Three Mile Island No. 2 nuclear facility on March 28, 1979, and thereafter. Attached is a detailed chronology of these events listed with the times they each occurred.
At about 4:00 am on March 28, 1979, tne secondary (nonnuclear) cooling system of the Three Mile Island facility suffered a malfunction. This system normally pumps water through the plant's steam generators where the water turns to steam which then flows to tui.* a turbine generator.
The water is then condensed back to water, is pumped by a condensate pump through a clean up system, throunh a feedwater pump, and finally back to the steam generators, and continually flows around this loop.
A malfunction in the main feedwater system caused the feedwater pumps to turn off (trip), which in turn caused the turbine-generator to turn off and stop generating electricity.
Since the steam generators were not remcVing heat due to the stoppage of feedwater flow, the reactor coolant system pressure increased and the pressurizer relief valve opened to reduce reactor pressure.
Imediately, the reactor turned off by the rapid insertion of the plant's control rods (scramed) as designed and the nuclear chain reaction stopped leaving behind only residual, or decay, heat. These events all occurred within the first 30 seconds following the evert.
105 C#J 98 ENCLOSURE 3
.g
. Up to this point, this sequence is nomal and the auxiliary feedwater system should startup and deliver secondary coolant to the plant's two steam generators to remove heat.
In addition, the pressurizer relief valve shculd close as reactor pressure decreases.
All three of the auxiliary feedwater pumps started but were unable to deliver flow because their flow paths were blocked by closed valves.
In addition, the pressurizer relief valve failed to close and therefore allcwed the reactor coolant system pressure to continue to decrease.
As the reactor pressure reached a preset value (1600 psi), the plant's Emergency Core Cooling System (ECCS) started as cesigned and began to inject cold water into the reactor.
It is at this point that an indication of a rapidly rising pressurizer level apparently led the plant operators to teminate the ECCS flow. At this point the Three Mile Island incident had been underway for 11-12 minutes.
Between about 1 and 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> into the transient, the operators turned off the four large pumps which circulate the reactor coolant through the reactor.
It is folicwing this action that we believe the severe damage to the nuclear fuel began.
For the next several hours there was a very large temperature difference across the nuclear core indicating little flow of coolant through the core.
105 ~0FrW
. Curing this several hour period, when severe fuel damage is occurring, primary coolant from the reactor primary coolant system was being dumped onto the reactor containment floor from flow out of the pressurizer relief valve and through the drain tank. This coolant, which contained radioactivity, was partially pumped 'from the reactor containment building floor to tanks in the auxiliary building. The tanks overflowed permitting radioactivity to be vented from the auxiliary building.
This situation lasted until about 9:00 am when the reactor containment was sealed (isolated).
During this time, from about 6:00 am until 8:00 pm, the licensee tried to depressurize the reactor coolant system sufficiently to be able to turn on the residual heat removal system. Since his attempts failed, it was decided to repressurize the system.
After repressurization, one of the main reactor coolant pumps was restarted and ficw through the reactor core was re-established.
Since feedwater was being provided to the steam generator, heat was being removed and the reactor system was sicwly cooled.
Reactor cooling has essentially been in this mode since that time.
\\ DS GEE so
v PRELIMINARY CHRONOLOGY OF
-THE MARCH 28, 1979 ACCIDENT AT THREE MILE ISLAND Time (accroximate)
Discussion of Events Before 4:00.am TMI operator working on Feedwater System.
4:00 am The loss of all (main and auxil'iary) feedwater flow occurred while the reactor was operating at 98% power. The transient was initiated by a loss of condensate pumps. The turbine tripped.
3-6 sec later An electromatic relief valve opened to relieve pressure in the RCS* (2255 psi).
9-12 sec later The Reactor tripped on high RCS pressure (2355 psi) to. terminate the nuclear reactor and reduce power generation to decay heat alone.
12-15 sec later The RCS pressure decayed to the point (2205 psi) where the relief valve should have reclosed.
The RCS continued to depressurize for about the next two hours.
15 sec later The temperature in the RCS hot. leg peaks at about 6100F with a pressure of about 2150 psi.
30 sec later The auxiliary feedwater pumos in both safety trains (1 turbine driven pump and 2 electrically driven pumps) were started and were running at pressure ready to inject water into the steam generators and remove the residual heat produced in the reactor core. No water was injected since the discharge valves were closed.
- Throughout, RCS denotes " reactor coolant system."
105 BE Si
, Time (acoroximate)
Discussion of Events 4:01 am The pressurizer level indication began to rise rapidly.
The steam generators, A and 8, had low levels of water and were drying out.
4:02 am The ECCS was initiated as the RCS pressure decreased to 1600 psi.
4:04-4:11 am The pressurizer level indication went offscale high and the operator manually tripped the first HPI pumps at about 4:04:30 and the second at about 4:10:30.
4:06 am Water in the RCS flashed to steam as the pressure bottoms out at 1350 psi.
The hog leg temperature was about 5850F.
4:07-4:08 am The Reactor building sump pump came on.
4:08 am The operator opened the valves at the discharge of the auxiliary feedwater pump allowing water to be injected into the steam generators.
4:11-4:12 am The operator restarted the ECCS to inject water into the RCS to control pressurizer level.
4:11 am The pressurizer level indication ccmes back on scale.
4: 15 am The RC Drain (Quench) tank rupture disk blew at 190 psig due to continued discharge of the relief valve that had failed to open.
4:20-5:00 am The RCS carameters stabilized at a satur-ated condition of about 1015 psi and 5500F.
5:15 am The operator tripped both RC pumps in Loop 3.
5:40 am The operator tripped both RC pumps in Loop A.
105 MM 52 Time (acoroximate)
Discussion of Events 5:45-6 am The reactor core began a heatup transient.
The RCS hot leg temperature went offscale at 620 degrees F within 14 minutes and the cold leg temperature dropped to near the temperature of high pressure injec-tion water (150 degrees F).
6:20 am The failed open relief valve was isolatad by the operator by closing a block valvt.
The operator also isolated steam generato.-
B to prevent leakaga of radioactive secondary water from leaking S.B. tubes.
7:f,0 am The RCS pressure had increased to 2150 psi and the relief vahe was opened to relieve RCS pressure.
' 15 1m A pressure spike of 5 psig occurred in the RC drain tank due to steam from the relief valve.
7:45 am A pressure spike of 11 psig occurred in the RC drain tank and the pressure in the RCS was a t 1750 psi.
9:00 am The pressure in containment peaked at 4.5 psig.
9:00-11:0C am The RCS pressure increased frca 1250 psi to 2100 psi.
11:30 am The operator opened the pressurizer relief valve to depressurize the RCS in an attempt to initiate RHR cooling at 400 psi.
12:00 am - 1:00 pm The RCS pressure decreased to about 500 psi and the core flooding tanks partially discharged.
The relief capacity was not sufficient to vent enough to reach 400 psi.
2:00 pm The pressure in the containment spikes at 28 psig causing containment sprays to be initiated.
The operator stcaped the spray pumps after about 2 minutes cf operation.
105 W 53
_ Time (acproximate)
Discussion of Events 5:30 pm The pressurizer relief valve was closed in order to repressurize the reactor coolant system.
5:30 - 8 pm The RCS pressure increased from 650 psi to 2300 psi.
8 pm RC pump in Loop A was started at which time tho hot leg tem:erature decreased to about 560 degrees F and the cold leg temperature increased to 100 degrees F, indicating flow through the steam generator.
Thereafter, the reactor was being cooled by reestablishing ~ condenser vacuum and steaming to the condenser by steam generator A with the RCS cooled to about 280 degrees F and 1000 psi.
M ch 29 The RCS temperature and pressure was stablized at about 280 degrees F and 840 to 1020 psi. The maximum reading on the incore thermocouples was 6120F, but several were not with range for computer readouts (printing "?")
which was subsequently found to indicate greater than 700 degrees F.
March 30 The RCS temperature and pressure was stable at nearly 280 degrees F and between about 1000 to 1060 psi.
Several incore thermocouples were beyond the range for computer readout, the maximum indicated reading was 659 degrees F.
The NRR staff estimated the bubble size in RCS to be about 1200 ft3 and requested the licensee to refine their calculation of the bubble size.
March 31 The RCS temperature and pressure remained stable at about 280 F and 1000 psi.
Slight drop in pressurizer level 251-191". Temperatures in the core as measured from the incore thermocouples were gradually decreasing (maximum indicated about SC00F). The hydrogen recor'her was in an operable statur but additional shielding was needed and was being obtained. Two samples of containment atmosphere were analyzed which shcwed a hydrogen concentration of 1.7% and 1.0%.
Licensee calculated bubble size to be about 620 ft3 3 875 psig.
105 GM Sf
- Acril 1 No substantial change in RCS temperature and pressure Incore themoccuples continue to show decreased trend.
Licensee continued hookup of hydrogen recombiners and addition of shielding. Licensee calculated valves of bubble size varied.
Containment air samples indicate 2.3% hydrogen.
Acril ?
Reactor pressure stable at about 1000 psi.
Incore thermoccuoles continued to show a decrease with all measurements balcw 4750c.
Inlet and outlet temperatures were still about 2800F. One hydrogen recombiner was put in operation.
Analysis indicated that the oxygen generation rate in reactor less than originally estimated. Measurements indicated that the bubble was being significantly reduced.
Acril 3 0
Reactor cressure and temperature stable at 1000 psi and 280 F, res;:ectively.
Thermocouole readings analyzed-maximum 4770F, only 3 thermoccuples were 0
above 400 F.
Gas bubble size much reduced. Containment about 1.9%
hydrogen. One pressurizer level indicator failed.
Acril 4 Reactor pressure and temperature stable at 1000 psi and 2800F, respectively.
Themoccuple maximum temcerature was 4660F. Gas bubble size decreasing.
Vent valve on pressurizer intermittently opened and degassing continues through letdown system.
April 5 Reactor pressure and temperature stable at 1000 psi and 280 F, respectively.
0 Maximum thermoc..fole reading is 4620F.
Pressurizer level responding normally to pressure changes indicating a completely full system.
Containment atmosphere indicates 24 hydrogen. One recombiner operating, one in standby. Pressurizer vented to containment about 15 minutes every 6-8 hours.
105 '$ff SS
L
- April 6 Reactor pressure stabl0 at about 1000 psi and temperature about 2850F.
At approximately 1:25 pm, reactor coolant pump 1 A tripped and reactor coolant pump 2A was started within about 2 minutes.
Shi f t in thermo-couple readings. The three thermoccuples previously reading about 4000F are presently reading between 2850F and 3150F.
Central thermo-couole increascd from 3750F to 4250F and is the only one reading about 0
400 F, Containment measurements indicate about 2% hydrogen.
Pump-back system for pumping waste gas decay tank volume to containment began..
Aoril 7 0
Reactor pressure and temperature stable at about 1000 psi and 230 F, respectively.
At about 8 pm, the licensee began to slowly lower reactor system pressure.
The slow decrease will end when react pressure reaches 500 psi. This is a step toward cold shutdown and includes degasification to prevent bubble formation as pressure and temperature decreases.
Hydrogen concentration in the containment is abot.t 1.9%.
105 t@
56
y-GENERIC CONSIDEPATIONS OE TMI-2 INCICENT The follcwing are the significant secuence of events that occurred at TMI-2.
a.
The turbine tripped due to loss of main feedwater, I
b.
The reactor tripped',
i i
c.
The auxiliary feedwater pumps started but flow was not auxcmatically established, d.
The pressurizer relief valve appcrently stuck open, e.
The hicn pressure injection was turned off, and f.
The reactor coolant pumps were turned off.
Our preliminary evaluation indicates that the incident may have been compounded by misleading indication of primary system water level.
In addition, the consequences of the incicent were increased by the lack of prompt autcmatic containment isolation.
The initiating event, i.e.,
turbine trip and subsequent reactor trip, are anticipated events in that they are expected to occur during the
[
f clant lifetime and the system is designed to respond safely.
In fact, l
cther S&W designed operating plants have excerienced these kinds of l
transients and have resconded safely. As a result of cur preliminary evaluation of the TMI incident, however, we have preliminarily identi Tec t
several human, design, and mechanical failures.
They are all essentially j
related to the icss of feedwater (item c above), ths ning off of tne ri;h cressure inje:tien, (item e abcve), and the turning uff the reactor 105 f@)
I s
ENCLOSUR *
-~
g-
. cooiant pumps (item f above). To ensure that these potential human, cesign, and mechanical failures do not result in a similar incider.t at other operating facilities, we have directed (via IE Bulletins) owners of facilities with B&W reactors to take several steps to ensure that safety margins are maintained.
In addition, we have formed an NRC Task Force to review in detail the causes of the TMI-2 incident and upon completion of these efforts will_ take subsequent actions as appropriate.
The Task Force report will be completed about the end of this month.
These NRC actions are also being taken at this time because of the preliminary nature of our evaluation.
Certain additional information will be developed which will provide additional insights into the actual cause. and consequences of the various actions during the event. At this time, however, our preliminary understanding of the event is sufficient to enable us to define the immediate actions required of operating facilities with B&W reactors to prevent such an occurrence at these plants, and provide us with an adequate basis to allow continued operation of these facilities.
First, the incident at TMI-2 was initiated by a loss of auxiliary feedwater allowing a turbine trip (item c above). Since plants are not designed and evaluated for the complete loss of all feetwater, we have taken steps to ensure that the emergency feedwater system will be available to inject water under this situation. At TMI-2, the block valves in the discharge lines from the auxiliary feedwater pumos were closed. We have required that operating facilities with S&W i 05 W10 58
3 reactors ensure that these valves are always open by requesting their specific examination of these valve positions.
The position indication will be further verified by a full-time fiRC IE inspector at each of these plants.
~
Another generic aspect of this event and a significant contributor was the apparent sticking open of the electromatic valve on the pres suri::er.
Licensees are being requested to examine their procedures such that operators are aware all valve positions, including the backup block valve to the relief valve, and have infomation available to permit its use. The sticking open of the relief valve was a significant contributor to this event and would be considered an important event regardless of whether auxiliary feedwater is available or not.
The second significant concern, which also has generic considerations, concerns the turning off of the high pressure injection system.
In general, we have requested all operators of plants to exercise extreme caution before turning off any safety system.
Specifically, we have taken steps to require operators to maintain high pressure injecticn for a minimum of 20 minutes if it is automatically actuated.
This occurs on low reactor pressure (1600 psi) in the reactor. We further require that high pressure injection be maintained until stable conditions are obtained. We believe such actions may cause c;erational inconveniences, but that they are not significant when compared to the gain to be made should a severe transient occur.
We also recuire 105 WD2 59
_4 cnat the LPI be maintained for 20 minutes following any lcw pressure trar.sients, including the case where a relief valve inadvertencly opens and sticks coen, to ensure pump coolant inventory.
Finally, we are requiring that if the reactor coolant pumos are in operation when a severe feedwater transient might occur, they should i
l be kept in operation if at all possible.
Furthermore, if possible, one I
should be 'Kept running in each locp. This requirement provides an 3
i extra level of safety to cover a broad variety of transients.
In developing this requirement, it was recognized that operation of the RCPs under certain conditions may damage the pump due to cavitation, however, it is believed that such operation is appropriate to ensure adequate response to a wide variety of transients.
The above mentioned staff requirements, in addition to our requirement
[
that all licensees with S&W reactors review their designs, have been imposed to maintain and possibly increase margins regarding their i
response to feedwater, and other, transients.
Such actions will, we believe, compensate for any remaining generic concerns regarding B&W.
i reactors response to such transients.
s Secause the accident situation appears to have been further corolicated by the containment not beinc isolated upon ECCS actuation, (in this case HPI), we have also taken steps to ensure that the conuinment is isolated to the extent possible given any particular event.
105 W bO
-S-The above mentioned considerctions have been directed to.;ards S&W reactors because they appear to be the ones most directly affected.
The described actions are intended primarily to be short term actions and may well be modified as a result of the NRC Task Force review of S&W reactor transients. Certain of these interim actions may also later be shown to be applicable to other pressurized water reactors, i.e., those designed by Westinchouse and Combustion Encineering. These facilities have significant design differences.
Two significant differences between the S&W primary system design and those of Westinghouse and Combustion Engineering are, first, the primary system water level for Westinghouse and Combustion Engineering are more directly measured. The operators would, therefore, have had a more direct indication of primary system water level and would have been so influenced before stopping high pressure injecticn flow.
I Secondly, the steam generator volumes are larger for Westinghouse and Combustion Engineering plants, and therefore are less sensitive to feedwater transients allowing more time to detect and correct any i
deficiencies in auxiliary feedwater flow. Therefore, we have not reouired any actions of licensees with Westinghouse and Combustion Engineering designed plants at this time, although we have been sending them information copies of all actions required of owners of E&W reactors.
\\o5 @vt
~, +-
f s
Three P.ile Island Incident Summary of Initial Response and Radiological Surveys At about 0700 hours0.0081 days <br />0.194 hours <br />0.00116 weeks <br />2.6635e-4 months <br />, the license identified high levels of radioactivity in the reactor coolant sample lines - there were "adiation readings of about 500 mr/hr at contact with the sample lines - and a " site emergency" was declared.
At 0730 hours0.00845 days <br />0.203 hours <br />0.00121 weeks <br />2.77765e-4 months <br /> the license declared a " general emergency" based. on high radiation levels in the reactor building, and began notification of certain Federal, State and local agencies according to emergency procedures.
At 0820 hours0.00949 days <br />0.228 hours <br />0.00136 weeks <br />3.1201e-4 months <br /> the radiation levels at the site boundary were repcrted to be less than 1 mr/hr.
NRC Regien I received notification of the general emergency conditicn at the plant at approximately 0745 hours0.00862 days <br />0.207 hours <br />0.00123 weeks <br />2.834725e-4 months <br />, March 28.
Af ter evaluation of the reported conditions, an NRC incident respense team was assembled and dispatched to the site and the situation was reported to NRC Headcuarters.
The NRC response team, consisting of reacter operations s;ecialists and health physicists, left the Region I Office at 08:5 hcurs and arrived onsite at 1005 hours0.0116 days <br />0.279 hours <br />0.00166 weeks <br />3.824025e-4 months <br />, March 28.
ENCLdShkh 5 @hd/
. Concurrent with the assembly and dispatch of the team, cperations centers were activated both at the Region I office and at NRC Heacquarters.
Natifi-caten procedures were initiated at both NRC Region I and NRC Headquarters to inform the Ccmmissioners, NRC staff and other State and Federal agencies.
At 0559 hours0.00647 days <br />0.155 hours <br />9.242725e-4 weeks <br />2.126995e-4 months <br /> the NRC notified the Department of Energy's Emergency Cperations Center at Germantown, Maryland and requested that an aerial survey (AMS, Aerial Measurement System) team be dispatcned promptly to the site.
The AMS helicopter arrived at the site and had located, tracked and mace measurements in the plume by 1515 hours0.0175 days <br />0.421 hours <br />0.0025 weeks <br />5.764575e-4 months <br />, March 28.
Returning to earlier events, the NRC incident team, arriving cnsite at 1005 hcurs, measured radiation levels of less than 1 mr/hr et the north gate, 3
~
mr/hr in the north parking lot and 7 mr/hr at the east side of the island.
The NRC team, after being briefed by the licensee regarding radiological and plant conditions, immediately set out to gather adcitional radiological data.
Radiation monitors in the plant showed abnormally high radiation levels in the containment and auxiliary building which prevented personnel access into certain areas.
Radiation surveys also identified elevated levels of radiation cutside plant buildings; hcwever, the condition cutside were not of such a level to prevent the gathering cf survey data.
Radiation surveys determined that a release of airborne radicactivity was cccurring.
105 D3$
03
3-At 1110 hours0.0128 days <br />0.308 hours <br />0.00184 weeks <br />4.22355e-4 months <br />, radiation levels of 3 mr/hr were measured at the plants' observation center on Route 441 immediately east of the plant, and at 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br />, levels of 0.3 mr/hr were measured on Route 283 near Harrisburg.
By the af ternoon of March 28, survey measurements shcwed radiation levels up to 15 mr/hr (Deta gamma) in the plume at ground level and levels generally less than 1 mr/hr (beta gamma) Outside the plume.
The highest measurement of about 70 mr/hr (beta gamma) was at 1620 hours0.0188 days <br />0.45 hours <br />0.00268 weeks <br />6.1641e-4 months <br /> at the north gate of the plant.
Aerial surveys the af ternoon of March 28 located the plume travelling in a N to NE direction in approximately a 30 sector, and radiation levels of 0.1 mr/hr were measured at about 16 miles frcm the site at an altitude of several hundred feet.
The aircraft survey identified, by gamma spectral analysis, the radioactivity as principally xenon-133.
By the evening of March 28, the agencies c0nducting radiation surveys and sampling operations included the licensee, NRC, DOE and the State of Pennsylvania.
In addition to the 00E AMS halicopter and aerial survey team and the NRC team and portable equipment, a mobile laboratory of the NRC Region I. office had arrived at the site to process and analyze samples.
Sampling and analysis of milk and air sampling for raciciedine had begun anc has continued to date.
Thus far, only Icw levels of radicicdine in
,i Get:
4 milk and air have been reported.
The levels are far belcw the level of action for control of dairy herds or milk.
The sampling will continue until seme time in the future and the results are continuing to be evaluated.
By March 29, the NRC team at the site had established a routine operation and procedures for obtaining both onsite and offsite radiological data.
This infermation was being relayed to the NRC Region I (Philadelphia) office and to the NRC operations center in Bethesda, Maryland.
Aerial surveys were being conducted at 3-6 hour intervals.
During March 29, radiation levels at the site boundary en the island ranged up to about 50 mr/hr (beta gamma).
The plume during the morning of " arch 29 extended in a N to NW direction, and aerial surveys measured 0.5 mr/hr at 1 mile arid 0.2 mr/hr at 10 miles from the site.
Offsite ground surveys measured levels generally less than 1 mr/hr during the day; maximum offsite radiation levels of 20 mr/hr (gamma) and 30 mr/hr (beta / gamma) were measured ene mile west of the plant in Goldsboro at 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />.
These levels persisted for.a short period of time, less than one hcur.
By the end'of March 30, the number of NRC staff at the site had grown to 83, including Regional Office and Heacquarters personnel.
Radiation surveys were more scheduled and routine.
Ground level surveys in offsite areas dcwr. wind frcm the site measured radiatien level rar.ging f rcm less 105
~
).
(pS
, than 0.1 up to 1.8 mr/hr.
Aerial surveys measured radiation levels of 8-10 mr/hr over the site, and levels of 6-8 mr/hr in the plume near tha site.
In the evening of March 30, the plume was tracked in a northwesternly westernly direction from the site and was not detectable beyond 5-6 miles away.
~
Sy the end of March 31, ground and aerial surveys were being ccordinated on a frecuent scneduled baris and the results being reported regularly to NRC Headquarters. Information on results of milk, water and air sampling as teing received and evaluated.
Results of licensee's TLD stations (18 stations within a 15-mile radius of the reactor) were received.
The TLDs had teen in place for three months and had been exposed for about 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> after the incicent.
Three dosimeters showed exposures above normal levels; the highest was from a station on Three Mile Island, 0.2 miles NNW of the reactor - 921 mr, approximately 905 mr above previous normal quarterly readings; the other high readings were 0.4 miles north of the reactor -81 mr, approximately 65 mr above previous normal quarterly readings and a station at north bridge, 0.7 miles NNE of the reactor - 37 mr, about 22 mr above normal quarterly readings.
On March 31, the NRC established 37 TLD stations within a radius of 12 miles of the site.
Two or more dosimeters were piaced at each station, one to be left indefinitely for integrated cose and the c.hers to be changed daily.
The first cay of this monitoring (March 31-April 1) shewed the 105 OM (ab
highest reading of 1.1 mr/hr at -mile ENE of the plant.
Other readings were much less and have decreased steadily since.
As of April 4, the folicwing information had been received on sampling and analysis for radiciodine:
Aporeximately.130 offsite water samples, analyzed by NRC, DOE and the Ccmmonwealth of Pennsylvania, showed no detectable radioicdine.
Apprcximately-150 offsite air samples had been taken and analyzea by NRC, COE, the licensee and the Ccmmonwealth.
Samples were collected at distances cut to 00 miles.
Only 8 of the samples indicated detect-
-13 able concentrations of icdine; these were in the range 2.7 x 10 gg 2.4 x 10'II microcuries/cc, the highest being about 1/4 of the MPC established for unrestrictec areas in 10 CFR Part 20.
Approximately 200 samp?es of milk had been analyzed by the State and FDA.
The results ranged frem minimum detectable activity to 41 picocuries per liter; there were two samples at or near the higher level.
By comparison, the HEW reccmmends placing dairy herds en stered food when icdine-131 in milk reaches 12,000 picocuries per liter.
Approximately 170 vegetatien saroles had been collected and analyzed by DCE, NRC and the Cc m nwealth of Pennsylvania.
Tne samples were 105 Gr3*)
67
. collected frca various sites within 2 miles of the plant.
None showed any detectable radiciodine.
Approximately 150 samples of soil ^were collected and analyzed by NRC and 00E.
None showed any detectable radiciodine.
As stated previously, sampling and analysis of air and milk for radiciodine is continuing.
As a further measure in evaluating the significance and health i ;plications of any radiciodine released from the plant, actions nave been initiated to have a selected number of persons analyzed in a "w hol e -b o dy", radiation measuring system.
The people selected would include both licensee employees who were onsite, and loca.1 offsite residents.
Recent aerial and ground level surveys results ir.dicate radiation exposure rates to be consistently less than 0.1 mr/hr.
105 W GB
m%
3
SUMMARY
OF RADICACTIVE LIQUID RELEASE SITUATION (IWTS)
The Industrial Waste Treatment Sump (IWT3) and the Industrial Waste Filter Sc=p (IWFS) normally collect nenradioactive liquid industrial wastes at the TMI f acility.
The normal sources of water to these sumps are ficor drains and other sumps located in facilities which do not have radicactive systems.
The IWF5 and IWTS are periodically discharged to the Susquehanna River by being pumped (approximately 130 gpm) into the cooling tower bicwdown which flows into the river at a location just Scuth of the Unit 2 mechanical i
draft ecoling tower.
The 60,000 gallon per minute cooling tower bicwdown cilutes the IWre/IWTS discharge by a factor of approximately 500 befcre it enters the river.
During the TMI incident, the high ccncentration of racicac.ivity in primary systems cross-centaminated normally non-radicactive secondary systems and ccntaminated water eventually ended uo in the IWF5/I'nTS.
The precise i O F) l t
lu-
,n (O~j ENCLOSURE 6
=
8 timing of these events is not known.
Tc preclude overflow of the IWFS/IWTS the licensee initiated discharge at about 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> cr Thursdsy, March 29.
Leg records show that the licensee censidered a contrclied diluted release a better alternative than letting the sump overficw with a resulting undiluted release to the river.
NRC analysis of water in the IWr5/IWTS at this time indicated the presence of Xe-133 ar.d Xe-135, but results were not crecisely known because the radicactivity in the gase:Us plume being released interfered with radiation counting instruments usec to analyze the sam:les.
However, it was determined that no iodine was present and the Xe concentrations were not consicered significant for the release pathway.
Pricr to the initial release NRC consulted with the State of Pennsylvania, Eureau of Rad Health who was in agreement with NRC's position to allcw releases as long as Technical Specifrations were met.
De State later, however, expressed concerns and at acproximately 1800 hours0.0208 days <br />0.5 hours <br />0.00298 weeks <br />6.849e-4 months <br /> on Thursday, March 29, NRC requested the licensee to stop discharging pending further analysis of the situation.
After consultation with the State, NRC and Pennsylvania subsequently authorized the continuation of release at 0C15 hours en Friday, March 30.
The licensee began makirg releases again at 0430 hours0.00498 days <br />0.119 hours <br />7.109788e-4 weeks <br />1.63615e-4 months <br /> on Fricay, March 30.
Intermittant releases continued until Monday, April 2, when the State of Pennsylvania recuested they be discontinued.
Due te a backlog cf camples for analysis, NRC did not beccme aware of radioiccine in the waste water until the sample ccunted at 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br /> en Saturcay, March 31; this samcie hac ceen cc11ectec at CcC0 hcurs that m:-ming.
Alsc, because samcles were being split with t.ne licensee's 105 042 70
- contractor, the samples were not being analyzed in the same order in which they were collected.
During subsequent analysis it was determined that icdine was initially present in the discharge on early Friday, March 30, as identified by a -sample collected at 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> on Friday, March 30.
This particular sample was analyzed at 0133 hours0.00154 days <br />0.0369 hours <br />2.199074e-4 weeks <br />5.06065e-5 months <br /> on Sunday, April 1.
Releases were again terminated at lil'0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> en Monday, April 2.
Several reasons exist for the approximate two day time frame between identification of radioicaine in the water and cessation of releases.
First, the NRC lateratory was merely processing samples and was not in a position to interpret the results.
Second, the feedback of results of sample analyses to those who might interpret them was nampered by the overall urgency of the =cment.
Third, the majority of samples were below the release limit, thereby making this a low priority matter relative to the other events at the time.
Af ter farther review of the matter and additional consultation with both the States of Pennsylvania and Maryland, jcint agreement was reached anc the licensee was again authorized to make releases on Thursday morning 4/5.
The licensee began discharging again at abcut 0300 hours0.00347 days <br />0.0833 hours <br />4.960317e-4 weeks <br />1.1415e-4 months <br /> on Friday with no further problems noted.
It should be noted that three organizations have been performing sample analysis.
NRC and the licensee's centracter were performing analysis on the scene and the samples were then forwarded to the State of Maryland for analysis.
Analyses performed at the scene were consicered preliminary because of counting interference caused by the gasecus releases frca TMI
~
105 b
nl 4
. 4 Ur.it 2.
Obviously, there would be some time delay in receiving Maryland's results.
It should also be noted that a State of Pennsylvania representative (Bill Dornsife) was at the scene throughout these events and was frequently receiving the results of all sample results.
This person stated that he had received all information in a timely manner.
Review of sample analysis indicates that the maximum concentration of
-4 aciciodine released was 2.7 x 10
- microcuries per milliliter (pCi/ml) of icdine-131, after cilution; this is approximately nine times the instantaneous release rate limit specified in the plant's Technical Speci-fications; the limits are the concentrations for unrestricted areas listed in Table 2, Appendix B,10 CFR Part 20 and whereas Part 20 allows concen-trations to be averaged over a year to achieve compliance, the Technical Specifications limit discharges to Part 20 concentrations on an instantaneous basis.
The majority of samples averaged approximately 2.4 x 10' pCi/ml or about 80% of the Technical Specification limit.
At no time was any radiciodine icentified in any river water samples collected downstream of the release point.
105 7A
N PRELIMINARY EVALUATION OF HEALTH EFFECTS OF THE THREE MILE ISLAND INCIDENT Radiation monitoring indicates that the exposure of the general popula-tion in the immediate vicinity of the plant was well within the limits of NRC regulations (10 CFR Part 20) for annual doses to members of the general populations.
They did exceed the numerical design objectives for normal reactor nperation of 5 millirem per year (Aopendix I to 10 CFR Part 50).
The sources of exposure were radioactive gases (xenon, krypton and iodine) that leaked from the plant - primarily from the auxiliary building.
Radio-active iodine (I-131) would be of particular concern because of its concen-tration in food, particularly in milk.
However, as of April 3, 1979, it appears that no more than 3.0 curies of radiciodine were released.
Iodine levels observed in milk samples are less than one-tenth of those observed in milk following the Chinese nuclear tests in the fall of 1977.
Tha predomi-nant radioactivity released from Three Mile Island was the noble gas Xenon-133.
The NRC has estimated that as of April 5, 1979, approximately 10 million curies of Xe-133 were released.
An independent estimate of Xe-133 releases by Lawrence Livermore Laboratory is 14 to 34 million curies, thus both esti-mates are in agreement considering the extent of the uncertainty in the estimates.
An ad-hoc dose assessment group of representatives frcm NRC, EPA and HEW have made estimates of the radiation doses to the population around the Three Mile Island plant, based primarily on monitoring of offsite areas 105 W 7.5 ENCLOSURE 7
k 2
by thermoluminescent dosimeters.
The calculated, total cumulative, 50-mile radius population dose from March 28 to April 8,* was approximately 2400 man-rems, which is equivalent to an average dose to individuals of 1.1 millirems.
The maximu1 dose to an individual offsite (hypothetical individual continuously present cut-of-doors at a location 0.7 miles NE of the plant) is still estimated to be less than 100 millirems (85 millirem).
This is within the dose limits recommended by the National Council on Radiation Protection and Measurements for annual doses to a member of the general public (170 millirem per year).
These estimates are whole body gamma doses resulting primarily from the relatively weak gamma radiation from Xenon-133 (80 kev).
The health impact of the estimate of maximum individual dose for a hypothetical individual exposed out-of-doors for entire duration at loca-tion of highest measured offsite dose can be considered in terms of the added risk of a fatal cancer.
The exicting lifetime risk of fatal cancer is approximately one-eighth (0.12).
The estimated risk from natural back-ground is approximately one to two percent of this value (0.0017).
The added risk delivered to the hypothetical individual would be 0.16% (0.000019) of the existing risk of a cancer death or about one percent of the estimated risk from natural radiation (1.1%).
The potential health impact of the estimated - population dose including fatal and non-fatal cancers and genetic effects to all future generations is 1.3 health effects; and the numoer of potential fatal cancers over the lifetime of the population is 0.45.
This ctn be compared to the existing cancer death rate of 4,300 per year and "From April 4th on, these values have been updated by members of the NRC Staff.
r 105 04
y 3
the estimated incidence from natural background radiation (125 millirem per year) of 54 per year. This supports the conclusion that the accident will not produce any detectable cancers within the lifetime of all of the residents in the area.
105 dad 7f
.,4 Resident Inspection Program In May 1977 the NRC decided to adopt a revised inspection program that, when fully implemented, will include assignment of resident inspectors to each cperating power reactor site, to selected fuel facilities and to power reactor sites in the later stages of construction.
This decision was based upon the results of a two year trial program of resident inspection which was completed in October 197c.
The trial program demonstrated that the concept of locating inspectors near reactor sites has the potential for increases in both effectiveness and efficiency when compared to the program of inspections conducted by inspectors based in a regional office which may be several hundred miles from a reactor site.
In May 1977, the Commission requested that OMB approve an amendment to IE's FY 1978 budget to provide resources needed to begin implementation of the revised inspection program. A FY 1978 supplemental request was sub-mitted to the OMB on September 15, 1977 and was signed by the President on Septenber 8, 1978.
The initial resident inspector under this program arrived onsite in July 1978.
Currently, there are resident inspectors assigned to 20 reactor sites.
As a result of the Three Mile Island accident, at each ce these sites with similar Sabcock and Wilcox designed reactors, a full-time inspec*cr was assigned to provide the equivalent of the resident inspection program.
A description of the Revised Inspection Program for Nuclear Power Plants was published as NUREG-0397 (March 1978).
The four elements of the revised inspection program provide a balanced examination of the activities of the licensee.
The revised program consists of:
Resident inspectors onsite at all reactors in cperation, at reactors in the late stages of construction, and at selected fuel facilities.
Region-based inspectors who will supplement the inspec-tions performed by the residents with nighly specialized inspections in such areas as environmental monitoring, physical security and health physics.
sa ENCLOSUREvS tQ tU
2 Performance appraisal inspectors to independently assess licensee performance, the effectiveness of the NRC inspec-tion program and to confirm.he objectivity of inspectors.
Increased independent verification of licensee activities.
The specific. requirements of resident, specialist, and performance-appraisal inspectors and of the entire program create a need for a com-prehensive approach to training, management of the inspection force and career development.
An expanded training program for all types of inspectors and an enhanced career management plan assure the performance of all elements of the inspection program by well trained and experienced inspectors.
In May 1977, the Commission requested that CMS approve a budget amendment for IE for 125 people and $5,000,000.
These resources were requested to allow IE to begin implementation of the resident inspection program in FY 1978 with full implementation in FY 1981.
In June 1977, the Office of Inspection and Enforcement developed its program plan for implementation of the resident inspection program.
This plan assumed timely approval of the budget amendment request and aimed toward having the first resident inspectors onsite in FY 1978 with full implementa-tion by the end of FY 1981.
The planned schedule was:
FY 78 FY 79 FY S0 FY 81 FY 82 Residents 35 46 111 133 152 In September 1977, the OMS approved a portion of the May 1977 request for additional resources.
This CMS approval provided for increasing the NRC full-time personnel ceiling by 75 to allow earlier implementation of the revised program.
Under this CMS-approved amendment (submitted to Congress in January 1978), the manning schedule was:
FY 78 FY 79 FY EO FY El FY 82 Resicents 22 49 76*
93 98 "All operating reactor sites manned.
At full imclementation, it was planned to have at least one inspector at sites with reactors in the later stages of construction, in pre-operational test, or in operation.
p'
\\
I
3 In September 1978, the FY 1978 supplemental recuest was signed by the President and the NRC was allocated 61 positions anc 52,650,000 for the revised inrrar+4cm pergram Tha Office of Inspection and Enforcement, in anticipation of approval of the FY 1978 suppicmantal had initiated recruit-ment efforts and was successful in promptly recruiting persm.t.el.
In the planning for the resident inspection program, an integral part of the revised program was a national. level performance appraisal effort.
This is intended to provide for (1) evaluation of NRC licensee performance from a national perspective, (2) evaluation of the effectiveness of the NRC inspection program, and (3) confirmation of the objectivity of NRC inspectors.
The modifications to the revised inspection program from the initial budget amendment request to CMS to the approved FY 1978 supplemental are:
Budcet amencment reouest for 125 additional oecole (May 1977)
Manning Schedule:
(Full Implementation)
FY 78 FY 79 FY 80 FY 8i FY 82 Resident 35 46 111 133 152 Inspectors Performance 42 78 119 157 157 Acpraisal Inspectors Full implementation in FY 1981 includes:
One inspector for each reactor phase (construction, preoperational testing, operations) at a site.
Additional inspectors so that no inspector would cover more than two reactors in any one phase.
105 5
'Itb
4 Accroved FY 1978 secolemental of 61 additional ceople Manning Schedule:
(Full Implementation)
FY 78 FY 79 FY 80 FY S1 FY 82 Resident 22 49 76 93 98 Inspectors Ferformance 10 15 17 28 33 Appraisal Inspectors Full implementation in FY 1981 includes:
One resident at each site with an operating reactor One resident at each site with a reactor in a later stage of construction One esident at each of six selected fuel plants Currently, there are resident inspectors assigned tu 20 reactor sites.
At these 20 sites a. e:
26 operating reactors 2 reactors in the preoperational test phase 6 reactors under construction As a result of the Three Mile Island accident, at each of three additional sites, an inspector was assigned to provide the equivalent of the resident inspection program.
On these three sites is a reactor of Babcock and Wilcox design similar to the Three hile Islar.d reactor.
The phased implementation of the resident inspection program resulted from the need to train newly hired inspectors, and the need to naintain a cualified base of inscectors in the regional offices. Currently, the imple-mentation of the program is on schedule.
\\0 W
POPULATION DOSE ESTIMATES During the week of April 1, joint NRC/ HEW / EPA ad-hoc study group agreed on the methodology to be used in estimating the radiation dose received by the populaticn within a fifty (50) mile radius of the site.
In addition, the-study group calculated the initial dose estimates up to April 4.
Using the agreed upon methodology, as of noon April 8, the MRC has estimated the total population dose within a fifty mile radius to be 2400 man-rem. There are approximately 2 million people living within the fifty mile radius of the site.
Thus, the radiation dose to an average member of the population is estimated to be in the range of 1-2 millirem.
It is estimated that the maximum radiation dose received offsite by a j
member of the public is less than 100 millirem (~85 millirem is the current best estimate).
This individual would have had to be continuously present cut-of-doors at the site boundary approximately 0.7 miles northeast of the reactor, which is the point at which the higher radiation dose rates were measured.
A
?
\\CS Y@O ENCLOSURE 9
- - _