ML14097A296
| ML14097A296 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/07/1979 |
| From: | Thompson D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| TASK-AS, TASK-BN-79-17 BN--79-17, PNO-79-067M, PNO-79-67M, NUDOCS 7904120087 | |
| Download: ML14097A296 (3) | |
Text
IMMEDIATE PRELIMINARY NOTIFICATION April 7. 1979 PRELIMINARY NOTIFICATION OF FVENT OR UNUSUAL OCCURRENCE--PNO-79-67M This preliminary notification 1c.ons.titutes summary information of an event of safety or public interest significance.The nformation presented is a su paryof information as'of7:00 a.
- m. on 4/7/79 Facility; Three Mile Island Unit 2 Middletown, Pennsylvania (DN 50-320)
Subject:
NUCLEAR INCIDENT AT THREE MILE ISLAND Plant Status:
The reactor pressure i s about 1075 psi with bulk core coolant inlet and outlet temperatures at about.8L5 F. At approximately 1:25 p.m. on April 6, reactor coolant pump 1A tripped and reactor coolant pump 2A was started within about two minutes. After the chanqe in operating pumps, there was a shift in the core thermocouple readings.
The three thermo couples that had.readings above 400' F are presently reading between 285' F and 315' F. The central thermocouple (position 8H) reading changed from approximately 3750 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 3Q4' F, The venting of Waste Gas Decay Tanks (WGDT)
"A" and "6" 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 "8V 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 cuncentrition in the conLainment was slightly greater than 2%.
The discharge to the river from the industrial waste storage tanks 1NST) was resumed at 6:15 a.m. on April 6. 1979 at an average rate of 10 qpm.
The INST level is now about 52%.
Environmental Status:
Off-site radiation levels as identified by NRC survey teams continue to range between 0.01 and 0.1 mr/hr.
These routine survey results were obtained on the east and west sides of the Susquehanna River at distances of four miles north and south of TMI.
Prevailind winds during April 6were from 270" to 300' (55E).
d*
CONTINUED 7904180 0
Continued April 7, 1979 Page 2 PNO-79-67M ARMS surveys were performed at 0700 and 1810 on April 6, 1979-The surveys identified a plume in the 1200-1400 sector during both flights, The maximum radiation level identified duringc the 0700 survey was 0.3 mr/hr one mile from the site at 900 feet elevation.
The 1810 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 minimum detectable activity (MDA) for this type of measurement is 10 pCi/1, The State of Maryland reported iodine 131 levels less than MDA (10 pCi/1) for one sample collected on April 4, 1979 and a.second collected on April 5, 1979.
Airborne concentrations for 34 EPA sample5 collected betweeiApril 4, 1979 and April 5 were reported as at or less than MDA (1.8 X 10" microcuries per milliliter).
No new data regarding vegetation and water samples have been reported.
Dose rates in populated areas as measured by NRC thermoluminescent dosimeters (TLDs) showed only minor changes from the previous day.
Minor fluctuations are expected at these low dose rates. Ten additional TLD stations at area schools were established on April 5 (making a total of 47 stations).
Following are the radiation dose rates for previously reported locations:
Dose Rate (Milliroentgens per Hour) 4/11/79 4/2/79 4/3/79 4/4/79 4/5/79 416/79 Falmouth 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 0.06 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 0.02 Emigsville 0.05 0.02 0.07 0.02 0.02 0.02
Contact:
DThompson, IE x28487 NCMoseley, IE x28160 CONTINUED
Contimued April 7* 1979 Page 3 PNO-79-67M Distributton Transmitted H St _
Chairman HriIe Commissioner Bradford S. J. Chilk, SECY Comissioner Kennedy Commissioner Ahearne C.- C. Kamerer, CA Com issioner Gilinsky (For Distribution)
Transmitted: MN88 P-. Bldg
-J y
L. V. Gossick, EDO H. R. Dentni FRR Region I H. L. Ornstein, EDO R. C. DeYoung, NRR Region 1I1 J.J Fuchard, PA R. J. Mattson, NRR Region1 III N, M.
M-Hller, MPA V. Stello, NRR Region IV R. G, Ryan OSP R. S. BoydNRR Region V H. K. Shapar, ELD SS Bldg (MAIL)
W. J. Dir. SNMSs J. J. Cummings.01A Saul Levine, RES R. Mino ue. SD Distribution:
(Provide copy to STATE)
White House Sit on EPA FDA/BRH DOE/EOC FDDA/FEMA BRP (State of PA)
DCPA HEW Handcarry (FAA)
IMMEDIATE PRELIMINARY NOTIFICATION L