ML19220C456
| ML19220C456 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon, Humboldt Bay, Crane |
| Issue date: | 04/28/1979 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| Shared Package | |
| ML19220C455 | List: |
| References | |
| PNO-79-067AI, PNO-79-67AI, NUDOCS 7905040360 | |
| Download: ML19220C456 (2) | |
Text
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IMMEDIATE PRELIMINARY NOTIFICATION
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April 28, 1979 FRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-79-67AI This preliminary notification constitutes summary information of an event of safety or public interest signi Heance The information presented is a sumary of information as of 7:00 a.a. on April 23, 1979.
Facility: Three Mile Island Unit 2 Middletown, Pennsylvania (DN-50-320)
Subject:
NUCLEAR INCIDENT AT THREE MILE ISLAND Plant Status The average coolant temperature is 179 degrees F.
Steam is bei.ng admitted to the main condenser through the turbine bypass valves from the A Steam Generator. The highest incore temperature reading is 319 degrees F.
Pressurizer level Lt-3 failed at 9: 15 a.m.
on April 27.
Pressurizet level is now being monitored by the back-up Heise Gauge and a mass balance calculation. Because of the degradation of the level instrumentation natural circulation was initiated ahead of schedule.
Reactor Coolant Pump 2A was shut down at 2:08 p.m. on April 27 and natural circulation was established on both Steam Generators.
Increasing levels of radioactivity were noted shortly af ter the start of steacing the B Steam Generator.
Offsite monitoring was conducted and the levels returned to natural background levels within three to four hours.
Steaming of the B Steam Generator was stopped at 1:10 a.m., April 28 due to an indicated increase in the level of ventilation stack activity. This indication was later found to be in error. Natural circulation is continu-ing on the A Steam Generator.
Environmental Status Aerial Measuring System (AMS) surveys were conducted from late mornir.3 until 6:00 p.m.
on April 27.
Xe-133 activity was detected up to 10 miles downwind (SSE).
Maximum readings were 0.2 nC/hr.
No iodine was detected during aerial surveys.
Offsite Measurementr.
Radiation Levels Offsite radiation levels indentified by NRC survey teams were consistent with the AMS Survey.
Readings from background to 0.35 vR/hr were present, in SSE direction from the site.
Dose rates (47 locations as measured by NRC thermoluminescent dosimeters (TLDs) 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 consistent with natural background levels.
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CONrisutD IMMEDIATE PRELIMINARY NOTIFICATION
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Continued April 28, 1979 l
t Page 2 PNO-79-67AI i
N2C Environmental Ssmoles (Samules taken offsite within 3 miles of site analyzed in mobile laboratory)
Number of Samole Type Date of sample Samples jlesults air 4/27 11 Less than MDA*
daily air 4/26-27 1
Less than MDA EPA Environmental Samples (Analyzed at Remote Laboratory)
Number of Sample Type Date of Sample Samples Results air 4/25-26 5
Less than}DA y
air 4/25-26 1
3.4 x 10 microcuries per cubic centimeter (0.34 picocuries per cubic meter) I-131 discharge 4/21-26 7
Less than MDA ater All EPA samples were taken at distances greater than 2 miles from the site
- MDA - minimum detectable activity.
EPA provided spike milk samples on 4/27/79 for taterlab comparison of analytical methods by each agency performing milk analysis.
The Commonwealth of Pennslyvania has been informed of these results. *'
Contact:
Dintribution:
Transmitted H St. b 3 Chairman Ifendrie Commissioner Bradford S.
J.
Chilk, SECY Commissioner Kennedy Commissioner Ahearne C.
C. Ka mme re r, CA Commissioner Gilinsk T
(For Distribution)
MNBB [$[,J.'.
P. Illdg /b.
b Transmitted:
J. G. Davis, IE L. V. Gossick, EDO H. R. Denton, NRR Region I H. L. Ornstein, EDO R. C. DeYoung, NRR Region II J. J. Fouchard, PA R. J. Mattson, NRR Region III N. M. Haller, MPA V. Stello, URR Region IV //.0?L) _
R. C. Ryan, OSP R. S. Boy #,NR Region V H. K. Shapar, ELD SS Bldg
('; _ NMSS J.
J. Cummings, OIA (MAIL)
W. J. Dircks, S.
Levine, RES R. Minogue, SD IE (TMI) Site _
(Provide copy to STATE)
C. Abraham, PA __
(Middletown - TMI-Information Center)
White House Situation Room FDAA
(
__ Provide copics to the Administrator and the Operations Center)
EPA DOE /EOC PDfA BRP (State of PA)
DCPA HEW qf j73 L0 8 " -
Handcarry (FAA)
IMMEDIATE PRELIMINARY NOTIFICATION s
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IDELIATE PRELIMIN.ARY ;OTTFtCATION g
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ITEl.TMT? ARY NOTIFICATION OF LVEh r Od UN!iSUAI. OCCURFENCE -- PNO-79-67AJ Tni-: pre)iminary nptificati>u con.Litute?, summary information of an event.
of safety or public lateresL
- i gn i f i can re_.
The infoggtloa presented is a suanary of informativu as of 7:00 a.n.
on April 29, 19/9.
F'a c ility,:, Three Mile is Iarnt Uni t 2 Middletown, l'ennsyl v.ini.a (DN 50-320)
Subject:
NUCLhAM INCIDENT AT TUREE MILE ISLAND i
Plant Status The average coolaut temperature is 175 degreca F.
Stesa is being admiLted to the main condenser through t.h c turbine bypass valves ironr the A Steam Generator.
The highest inenic temperature reading is :120 degrees F.
Natural circulation is ren'inuing on the A Steam Generator.
Envicoamental Status Two Aerial Nearuring System (AMS) Surveys were cade on Apr:I 28, 1979 No radioactivity above natural backaround was detected.
Iodine concentration at Unit 2 ventilation stack (Analy..ed by NHC Mohite Laboratory).
Date/ Time A,rtivity (uCi/cc) 10'8 4/27 (0011) - 4/28 (0033) 1.11 x 4/28 (0042) 4/28 (0830) 3.35 x 10 "
4/28 (0832) - 4/28 (1625) 9.51 x 10' Of f e.i te Measurements Radi a t.j nn Levels Offsite radiation level:s identified by NRC survey teams continue to b -
con 9i3 tent With natural backgroima Irvels (0.02 r3/hr ruasimum).
These resillts were obtained from rontinc daily surveys periormed downwinni on the Oaat and west s i der; of the Susqnchanna KlVer at diblantes up Lo five mile.
north and euuth of the nitc.
Duse ra tes (47 locations) as measured by NitC thermoltainescent dosimeters (TI.Ds) for the past 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period tuntinue Lo be consint.ent. with natural harkground levels.
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