ML19220A836
| ML19220A836 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/09/1979 |
| From: | Jordan E, Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-79-067P, PNO-79-67P, NUDOCS 7904250018 | |
| Download: ML19220A836 (3) | |
Text
(CORRECTED COPY)
TA e
w IMMEDIATE PRELIMINARY NOTIFICATION April 9, 1979 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURREHCE--PHO-79-67P*
This preliminary notification constitutes summary information of an event of safety or public interest sionificance.
The_information presented is a summary or information as of 6:00 a.m. on 4/9779.
Facility:
Three Mile Island Unit 2 Middletown, Pennsylvania (DN 50-320)
Subject:
NUCLEAR INCIDENT AT THREE MILE ISLAND Plant Status Bulk coolant inlet and outlet temperatures are about 280 degrees F.
The average core thermocouple temperature is about 300 degrees F, and the highest thermocouple reading (8H) is about 425 degrees F.
At approximately 0430 hours0.00498 days <br />0.119 hours <br />7.109788e-4 weeks <br />1.63615e-4 months <br />. April 9, the reactor coolant system pressure reached the 400 psig endpoint established for the second degassing evolu-tion.
At lower pressures in the 400 to I,000 psig range, noise monitoring indicated possible presence of some gas in Loop B of the reactor cooling system.
Noise monitoring verified re-solution of gas with time.
The operating reactor coolant pump vibration increased to 8.5-9 mils but the level of vibration was still significantly below the limit (30 mils).
Pressure variation for degassing is continuing.
Following reduction to 400 psig, the licensee plans to increase pressure to the 900-1,000 psig range and a phased cooldown is under consideration as the next step.
The licensee requested and received permission to temporarily change the minimum pressurizer level to 150" from 200" to prevent high pressurizer levels on pressure decreases.
At approximately 1320 hours0.0153 days <br />0.367 hours <br />0.00218 weeks <br />5.0226e-4 months <br />, April 8, the reactor coolant system began to heat up.
This was due to a decrease in steam generator level.
Steam Generator A level was increased to decrease the primary temperature.
Hydrogen concentration in containment is about 1.85%.
At approximately 1942 hours0.0225 days <br />0.539 hours <br />0.00321 weeks <br />7.38931e-4 months <br /> EST, the last airplane involved in the filter airlift left Pasco, WA, for Harrisburg, PA.
CONTINU5D(CORRECTEbCOPY) x (The letter "0" was not used, previous issuance was PNO-79-67N) 70'130 7.9 0 4 2 5 0 ol%
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t Continued April 9,1979 Pace 2 CORRECTED COPY PNn-70-670 ENVIRORMENTAL STATUS Offsite radiation levels identified by NRC survey teams continue to range between 0.01-0.1 mR/hr.
The results were obtained from routine surveys performed on the east and West side of the Susquehanna River at distances of up to 4 miles north and south of the site.
The following ARMS surveys were conducted during April 8, 1979:
MAXIMUM TIME RADIATION LEVELS LOCATION DISTANCE FROM SITE 00:00-00:30 1 mR/hr i
sector 180
- 1 mile (south) 06:00-06:20 0.3 mR/hr i
sector 200*
?. mile (west-southwest) 09:00-09:50 0.03 mR/hr sector 170 1 mile (south-southeast) 18:05-18:30 0.05 mR/hr sector 275 3 miles (west-northwest)
Eight offsite air samples collected near the NRC trailer during April 1-8 indicated iodine-131 concentrations between 0.9 - 3.3 picocuries per 3
cubic meter (pci/m ).
The maximum permissible concentration per 10 CFR 20 -
is 100 pCi/m.
3 No new data were reported for milk, water, and vegetation samples.
Offsite dose rates as determined by NRC thermoluminescent dosimeters (TLDs) indicate that present radiation levels are in close agreement with expected natural background levels.
Minor fluctuations among individual TLDs are expected due to the limitations of the TLD system.
Forty seven TLDs are presently positioned at various locations arcund the site.
Dose rates (47 locations) as measured by NRC thermoluscent dosimeters have ranged from 0.01 to 0.02 milliroentgens per hour for the past 24-hour periods of April 7 and 8.
CONTINUED (CORRECTED COPY)
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Continued April 9, 1979 Page 3
___ _ CORRECTED COPY PNO-79-57P
Contact:
EJordan, IE x28180 NCMoseley, IE x28160 Transmitted H St M,b f 9
Distribution:
Chairman Hendrie Commissioner Bradford S. J. Chilk, SECY commissioner Kennedy Commissioner Ahearne C. C. Kammerer, CA Commissioner Gilinsky (For Distribution)
Transmitted:
MNBB /d/dd P. B1 'g /0!o"A 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, NRR Region IV R. G. Ryan, OSP R. 5. Boyd NR3 Region V 3
H. K. Shapar, ELD SS Bldg /0,'O y (MAIL) e W. J. Di rcks, NM55 J. J. Cummings, DIA S. Levine, RES R. Minogue, SD
' i.
IE (TMI) Site ad([22)7 (Provide copy to STATE)
White House Situation Room EPA FDA/8RH _
DOE /EOC FDDA/ FEMA BRP (State or PA)
DCPA HEW Han1 carry (FAA)
IMMEDIATE PRELIMINARY NOTIFICATION CORRECTED COPY 7C 13?