ML060330052
| ML060330052 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/25/1979 |
| From: | NRC/IE |
| To: | |
| Shared Package | |
| ML060230218 | List: |
| References | |
| PNO-79-67AF | |
| Download: ML060330052 (7) | |
Text
IMMEDIATE PRELIMINARY NOTIFICATIOJ Ap'ril 25, 197 PRELInNJARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -PNO-79-67AF This preliminary notification constitutes sumary information of an event of safety or public interest significance.
The information preseuted is a0 a.m. on April 25, 1979.
Facility:
Three Mile Island Unit 2 Middletown, Pennsylvania (ON 50-320)
Sgubject:
NUCLEAR INCIDENT AT TREE MtILE ISLAND Plant Status In the course of transferring feedwater flow to the auxiliary nozzles, a carryover of water into the steam line was experienced, resulting in water impingement in the main turbine.
An operator-initiated turbine trip at about 3:00 p.m. stopped the impingement.
The feedwater was being diverted to the auxiliary feedwater sparger in preparation for secondary system modification for adding a closed cooling system.
Steam is currently being admitted to the main condenser through the turbine bypass valves.
This chaon;e in cooling mode will not affect
< preparations for natural circulation operations.
The average primary coolant temperature has increased to 224 degrees F.
The highests incore thermocouple reading. is 312 degrees F.
As a result of changing the charcoal filters in the A Trains of the Auxiliary and Fuel Randling Building Ventilation Systems, the iodine discharges have been reduced by approximately 80 percent.
The charcoal filters of Auxiliary Building Ventilation System Train B have been replaced.
This system was placed in service at 5;30 a.m.
April 25.
Following a briefing of the Governor's Office, a press briefing was held to outline the anticipated schedule for achieving long term cooling status.
A copy of the press release is attached.
Enviroxnental Status Three Aerial Measuring System (ARMS)
Surveys were made on April 24, 1979.
No radioactivity above natural background was detected.
E CONTINUD
.>IMMDATE PRELIMINARY NOTIFICATION 7 9 0 5 ozcoZS 30
? 5
I Continued P*ge 2 April 25, 1979 PNO-79-67AE Iodine concentration ac Unit 2 obkile Laboratory).
Daoe/Time ventilation stack (Analyzed by NRC Activity (uCl/cc) 4/24 4/24 4121 4/24 4/24 4/24 (0408)
(:062)
(0815)
(1217)
(1602)
(1958)
- 4/24
- 4/24
- 4/24
- 4/24
- 4/24
- 4/25 (0637)
(0813)
(1215)
(1600)
(1955)
(0001) 3.0 x 4.2 x 3.1 x 1.6 x 2.4 x 2.6 x
-s 10 1o8 10 Offsjte Measurements Radiation Levels Offsite radiation levels identified by NRC survey teams continue to be consistent with natural background levels (0.02 mR/hr maximum).
These results were obtained from routine daily surveys performed downwind on the east side of the Susquehanna River at distzances up to five miles north and south of the site.
Doze rates (47 locations) as measured by NRC thermoluminescent dosimeters (TLD&) for the past 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period continue to be consis-test vith natural background levels.
NKRC Enviromental Samples (Samples takeua offsite within 3 miles of site analyzed in mobile laboratory)
,i I
I SaPle Type air milk daily air Date of Sample 4/24-25
£4/23 4/23-24 Number of Sampales 3
1 Results Less than HDA*
Less than lDA Less than NDA EPA Eaviromental Samples (Ansl zed at Remote Labt Number of Sample Type Date of Sample Samples air 4123 28 air 4/23 3
5ratory)
Results Less than KDA Range from 2.3 to 7.1 x 101 microcuires per cubic centi-meter (0.23 to 0.71 picocuries per cubic meter)
One sample was less thin tDA.
One sample indicated 168 picocuries per cubic meter of Xe-133.*k Both samples indicated approximate background levels of Kr-85.
Ar-ai r 4/20 2
CONE U IMMEDIATE PRELIMINARY NOTIFICATION
I Continued Psac 3 April 25, 1979 PNO-79-67A All EPA s les vere taken at distances greater than 2 miles from this site.
- HIDA - mixiam detectable activity.
- Maiim= Permissible Concentration for Xe-133 is 300,000 picocuriei per eUic-meter.
The Comonvealth of Pennsylvania has been informed of these results.
Attschment:
Press Release Dated 4/24/79 Contact z Distribiution:
Transmitted Hi St 2__tr Chairman Hendrie Comwmissioner Bradford Counissioner Kennedy Commissioner Ahearne CoMis2ioner Gilinsky Transaitted:
WiBB (P.
Bldg
- 1. V. Gossick, EDO H. R. Denton, NRn H. L. OrnsteiLn, EW R, C. DeYoung, M
J. J. Fouchard, PA R. J. Iattson, VR
- J. 1. Haller, MPA V. Stello, NRR R. G. Ryan, OSP R. S. Boyd, NRR H. K. ShApar, ELD SS Bldg V. J. Dircks, NMSS S. Levine, RES S. J. Chilk, SECT C. C. Kaumerer, CA (For Distribution)
J.
G. Davis, IE Regionl I ____
Region II Region IlI Region IV Region V J. J. Cumnings, OL R. Hinogue, SD a,
IE (THI) Site (Provide copy to STATE)
White House Situation Room YDAA (Provide copies to the Administrator EPA DOE/EOC PEIA ___
UHP (Statc of PA)
DCPA IEW (Picku p) flandcarry (FAA) and the Operations Center) i Mi L PRELIMfINARY NiOTIF-ICATION
- EEIUU.
uh:mIg Attachment to PNO-79-67A-1 l
-FOR X'HHEDIAT
}-LAS April 24, 1979 e Nl-ERC staff today announced a timeble for plcing t Three
-ile Isad :Unit: 2 reator on natural circulatin cooling.
A stated on previous Oe ca s
it is tow possible o cop,he reactor by na tural convection circulation if difficulties arise
- it~h presently operating equipment.
It is, of course, preferable to Plae the plant on. tural circulation in a planned fashion
-w shile presently available plant itrnts and eqi t
ctA ong; However, lf inrumentation in the plant loes not eta-n *ts reliability and the various
'taclop tbods preenly avilable do not fictiit maeybe neessary to lce the: plnt on; atural crculati at that. time.
The excessive noo-condeasable gases in the system have been removed and are now at an acceptable level.
The phased reduction in primary system temperature has now rea-ched a~p~proxi~mtely 17567.
This re~lct-io ina temp-erature is ate thaA originaly anticipated with sLeaming in the steam gSetrator Asaumiug current instrumentation continues to perform satisf-ctoroIyr, lthe follcsi.g timetable for a planned transition Lo natural circu-t loA as been established.
The sequences planned to reach this objective are:
- 1.
The '"B" steam generator will be placed in a water solid condition by April 29th.
- 2.
The "A'"
steam generator w:ltl be placed in a water solid condition by April 30th,
-3.
Action needed to upgrade the backup cooling capability of the existing decay heat removal system will be completed by
- nay 1.
- 4.
With these steps completed, the primary system recirculation pump will be shut off on flay 2nd and the system will then go into natural circulation.
There are01-number of other og;oing actions at the plant.
- 1.
Radioactive effluent filter systems within the plant have been upgraded.
An inrdependent redundant charcoal filter system, which will serve aes a second sLage of removal, has been under construction fcgr some time.
The new system is
- expected to be operational. by h1ay 2cd.
4.
-m 2
- 2.
Hodificativas are currently in progress that will permit the secondary side of the I'S steam generator to be operated in a closed system, i.e., without the need for the avaig-kility of the main condenser.
This activity is scheduled for comple-tion for May 7th.
Closed system cooling of steam generator B is not essential to establish stable natural circulation cooling.
- 3.
The A steam generator also will be modified to permit operation in a closed system.
This modification also is not required to establish natural circulation.
Its schedule for completion is currently estimated to be the middle of May.
- 4. The passive level and pressure control system that will augment existing plant systems is expected to be completed by mid-May.
This system is not needed to achieve natural circula-tion, but it is prudent to add this redundancy to the existing plant equipment for long term monitoring of natural c-ircula-tion cooling.
5.
Modifications on the onsite electrical system are currently being made.
Additional diesel jeneratars have been delivered to the site to provide a backup-power supply, and are currently being placed on their foundations.
Electrical instrumeatation and other necessary connections will be completed by Apr-I 27th.
- 6.
There are a number of additional modifications being made within the facility that are related to the long term recovery from the accident.
Such. modifications include:
adding an additional decay beat removal system with equipment to process and remove the radioactive materials from the primary coolant system; the installation of additional tanks to provide for storage of contaminated water that may result from decontamination activities; installation of additional contaminated water processing equipment, and general decon-tamination activities needed in the auxiliary building.
DDMMIATE PRELIMINARY NO-TIT'lCA'f loN
.April 28&,
1979 PRtX~h'fy~NOfTlCATIOjq OF EVENT OR tM)sUAL~ OCCURRENCE - PNO-79 67AI Thisprelminay ftifcatict constitutes; swimary information VE an event ofsaet o
~b~
nterest al~ntfeied
.The Informaionbi prtented is
- fUaryof ifora~io asof 700a.m. onA Aril 28 -1979 facility: 1hre Mile Islesd Uit -2 W1ddlli'oA,, Pennsylvania (D)J-SO-320)
EUt Et: 'NUCLEAR~
INCWIDM AT THREE NM'l IS AN
?lant StAtus The average tG tne mrai 5.Genertor.
cQQ1ant temperature is 179 degrees F.
Steam is being adait"e codeaser~ through the turine cbypas val-ve f rm h A Stvea The higrest icoze teperature rcadig is 319 -degrees F i
Pressurizer level Lt-3 failed at 9:15 a.am. on April,7.
-Presurizer level is now beig mon~itored by the back-up Heise Gauge and a Mass balAne calcu Itioz.
aecause of the degra4ation of the level instrumentation natura. -ciculaon ve initiated abead ef acbe4e. Rcactr Coolant Pum 2A was Veshut down at 2::08 p.m. on April 27 and natural eiremlation wa estabshsed on boh SteBam Oeerators.
Increasing levels of radioactivity were Noted shortly after te saxt4 of steaming the B Steam Generator.
Offuite monitoring wAs ndct and the levels returned Lo natural background levels within three to four hours.
Steaing of the B Steam Generator was stopped at 1:lQ a.m., April 28 due to en indicated increase in the level of ventilation stock activity.
This indication was later found to be in error.
Natural circulation is continu-in#g on the A Steom Generator.
Envi rouzental Status MriAl rleasuring systesn (CAS) surveys were conducted from late morning unt.1 6404 p.m. on April 27.
Xe-133: actIvity was 'deteeted up to 10 iles dowzid (oS:. maxul m readings were 0.2
-mhr.
No iodipe was detected dx
- eStal surveys.
Offs ltetKeaatreaents adiation ;Le~vels ding O
radiation A 1*U indentifted by NWC survn.ey tem were co 0tiet vI4ntA5 vy.
ea-i from back round to 0
-mR/hr were P:ese-t in E di~ction frm the site.
- ose-rates (47 locations as meeasured by liRC thermoluminescent dozimetet,'g (D)
(oqr-the pa t 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period contimae to be conuistent with tural beegrund levels.
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- 7.
.1 7MtS I1EW~AT9 FIMI-lIUJW j1WOIFICATIOW' ThS)'c~
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. P.-, i I id
Cc~n~wjed April 2S. 17
~IR £vionegta Swpes(SAMplCS 4ken W~si Jte thiibn 3.-miles Of site.
SAD3 ye Dte o*f Samole AS"Amoles eut EPAEnvronentl Smpls (alyed at:Rewute Laboratory) an m*
anX JAk 4:1 SchargeW Date of sposle 4125-26 iu/0$-26 Ruambr, of Samiples I
Results 3.4 z7-19 AV rcu per ctsbic cenrimte-r-meter)I'3 tons thin =lA 4/21-26 7
- e All.EPA samples were taken at distances greater thian 2 ;iles from tite DA mvinimum de tectable activity.
EPA pzovided spike milk saples on 4 27179 for inftermb comparisOn of analical ethoon hby each agency perfosring milk analyss.
The Cqmowealt of Pennulyvania bfs been informed of these rosaxts-
,Contact:
Ditsri-butioa:
Transmitted k9 St Charwal Eendrie Comoissioner Bradford S. J. Chilk, $KECT4 Co~usssiocr KnnedyCommsu~iner 2arne C.C aegr
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