ML19263D853
| ML19263D853 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 04/07/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 7904130333 | |
| Download: ML19263D853 (1) | |
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'I UNITED STATES
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WALNUT CRE E K. C ALIFORNI A 94596 April 7,1979 Docket flo. 50-312 Sacramento Municipal Utility District P. O. Box 15830 Sacramento, California 95813 Attention: Mr. John J. Mattimoe Assistant General Manager Gentlemen:
In accordance with our letter dated April 1,1979 transmitting Bulletin 79-05, we are enclosing Preliminary flotification 79-67M.
Sincerely, d/> d7/dda;.A-R. H. Engelken Director Enclosure Pfl0-79-67M cc w/ enclosure:
R. J. Rodriguez, SMUD L. G. Schwieger, SMUD i,
7904130333 l
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If4ffEDIATE PRELIMIriARY fl0TIFICATION April 7, 1979 PRELIMINARY NOTIFICATION OF FVErlT OR UNUSUAL OCCURRENCE--Pfl0-79-67M This preliminary notification constitutes summary infomation of an event of safety,.0,r public tn't'e'rc's't s'1lgnfficance~-~ The information presented is a
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s.upiqary..of.,i_n.f.o,rma,t1on, as _o,Y 7:00 a.m. on 4/7/7<),
if.G' Facility:
Three liile Island Unit 2 j.,
Middletown, Pennsylvania (D?l 50-320) 2,
Subject:
NUCLEAR IflCIDEtiT AT THREE MILE ISLAtlD Plant Status:
The reactor pressure is ; bout 1075 psi with bulk core coolant inlet and outlet temperatures at akut 406" F.
At approximately 1:25 p.m. on April 6, reactor coolant pumn lA tripped and reactor coolant pump 2A was started within about two minutes. After the channe in operating pumps, there was a shift in the core thermocouple readings. The three themo-couples that had readings above 400" F are presently reading tetween 285" F and 315" F.
The central thermocouple (position 8H) reading changed from approximately 375' F to 455" F and is now reading 453" F, the only reading above 400 F.
The average temperature of the 30 thermocouples being monitored is 304* F, ENi-I f.73 The venting of Waste Gas Decay Tanks (WGDT) "A" and "B" to the containment building was resumed at 9:15 a.m. on April 6,1979 and stopped at about 3:00 a.m. on April 7 when the pressures of WGDT "A" and "B" were 32 and 30 psig, respectively.
At the time the venting was secured, a small release occurred resulting in radiation readings somewhat lower than previously experienced during such operations.
Following venting of the WGDT to containment, the hydrogen contentration in the containment was slightly
.jg greater than 2%.
a The disci,
'e to the river from the industrial waste storage tanks (IHST) 1,.
was resumeo at 6:15 a.m. on April 5,1979 at an average rate of 100 gpm.
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The INST level is now about 52%.
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_E_nvironmental status:
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Off-site radiation levels as identified by NRC survey teams continue to ran0e between 0.01 and 0.1 mr/hr. These routine survey results were obtained on the cast and west sides of the Susquehanna River at distances of four miles north and south of TMI.
Prevailinn winds during April 6 were from 270" to 300* (55E).
CONTINUED I)6 7904120087 D
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Continued April 7,1979 Page 2 Pfl0-79-67ti APJtS surveys were performed at 0700 and 1810 on April G,1979. The surveys identified a plume in the 120"-140' sector during both flights.
The maximum radiation level identified during the 0700 survey was 0.3 mr/hr one mile from the site at 900 feet elevation.
The 1310 flight identified 0.05 mr/hr three miles from the site at 500 feet elevation.
The State of Pennsylvania reported an iodine 131 level of 12 picocuries per liter (pCi/1) for one milk sample collected on April 5,1979.
Pennsylvania's ninimun detectable activity (MDA) for this type of r.casurement ~
is 10 pCi/1.
The State of tiaryland reported iodine 131 levels less than HDA (10 pC1/1) for one sample collected on April 4,1979 and a.second 4
collected on April 5,1979.
Airborna concentrations for 34 EPA samples collected betweeT3 April 4, 1979 and April 5 were reported as at or less than f1DA (1.8 X 10-microcuries per milliliter).
fio new data regarding vegetation and water samples have been reported.
Dose rates in populated areas as measured by f1RC thermoluminescent dosimeters (TLDs) showed only minor changes from the previous day. Hinor fluctuations
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are expected at these low dose rates.
Ten additional TLD stations at area schr-1s were established on April 5 (making a total of 47 stations).
Feifomg are the radiation dose rates for previously reported locations:
Dose Rate (Milliroentgens per Hour) 4/1/79 4/2/79 4/3/79 4/4R9 s/5/79 4/6/79 Falmous.
0.15 0.01 0.20 0.04 0.02 0.02 Middletown 0.04 0.01 0.02 0.01 0.01 0.01 Goldsboro 0.13 0.05 0.07 0.07 0.05 0.03 Goldsboro - South 0.04 0.02 0.05 0.02 0.03 0.02 Lewisberry 0.05 0.02 0.04 0.03 0.02 0.02 Pleasant Grove 0.04 0.02 0.05 0.01 0.01 0.02 York Haven 0.07 0.02 0.10 0.05 0.01 0.02 Conewago Heights 0.04 0.02 0.07 0.02 0.01 0.
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Emigsville 0.05 0.02 0.07 0.02 0.02
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contact: DThompson, IE x28487 hCMoseley, IE x28160 s
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+t Continued April 7, 1979 Distribution: Transmitted H St f/ N Cnairt.1an Hendric Corrmissioner Bradford S. J. Chilk, SECY '
comissioner Kennedy Co,missioner Ahearne C. C. ramerer, CA
(
Comissioner Gilinsky (For Distribution)'
Transmitted: MNBB fM P. Bldg f[I[
J. G. Davi L. V. Gossick, EDO
- 11. R. Denton, flRR Region I H. L. Ornstein, EDO R. C. DeYoung, t<RR Region II pRegion.III' J. J. Fouchard, PA R. J. Mattson NRR
~ Region IV fl. M. Haller, MPA V. Stello. NRR R. G. Ryan, OSP R. S. Boyd NPR Region'V-
- 11. K. Shapar, ELD SS Bldg 9.'
(MAIL).
W.. J. Dircks. NM55 i J. J. Cumings. OIA Saul Levine, RES R. Minogue. SD Distribution:
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TE (IMI) Site: White liouse SitEtEn Yoora(Provide copy to STATE)
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IMMEDIATE PRELIMINARY NOTIFICATION N'
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