ML19224A760
| ML19224A760 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/02/1979 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| References | |
| PR-790402, NUDOCS 7905300220 | |
| Download: ML19224A760 (1) | |
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TECHNI CAL UPDATE ON CURRENT S I TUATION AT THREE MILE ISLAND April 2, 1979 Plant Statu3 Reactor pressure is being held at about 1000 psi, incore thermo-couples centinue to show a decrease in fuel channel temperatures, with all neasurements belos about 475 degrees F as of 4: 00 p.m.
Bulk core inlet and outlet temperatures are about 280 degrees F.
At 10: 30 a.m.,
April 2, a containment air sample indicated about 2% hydrogen. At about J:45 p.m. April 2 the first hydrogen re-combiner was placed in service and had reached operating tempera-tures by about 4:15.
Recombiner instrumentation indicates about 2% hydrogen concentration in the containment air.
Further analyses and consultations with experts has led to the development of a strong consensus that the net oxygen generation rate inside the noncendensible bubble in the reactor is much less than original conservative estimates.
Also, meas urements at th-plant appear to indicate that the volume of gases within the bubble is being signi ficantly reduced.
Plant instrumentation is being closely followed to confirm these favorable indications and to better understand the characteristics of the processes associated with decr, easing bubble size.
Environmental Status Thi rty-seven the rmoluminescent dos ime t ry (TLD) stations were established by the N3C.at distances from about one mile to about 12 miles from the plant. Hultiple dosimeters are placed at' each location - one will be left in piace for a cumulative dose measure-ment; another is pulled and replaced each day.
The highest dosimeter reading was recorded at a location 1/2 mile ENE of the plant.
The dose rate of this location was 1.1 milli-roenitger per hour.
The next highest was 0.4 mr. pe r hour 0.4 miles east of the site. All the remaining samples were 0.1 mr per hour or lower.
Aerial radiation surveys cont.inued at three-hour intervals on April 1, and 2, 1979.
The plume readings were essentially the same for all the flights.
Direction of the plume varied f rom SW to WNW.
The maximum level at one mile from the plant was about 3 mR/hr at an altitude of 500 feet. At three miles, the levels were from 0.1 to 0.5 mR/hr.
Offsite ground level surveys taken between 11:00 a.m. April 1, and 4:30 a.m.
April 2, on both sides of the river in a southerly direc-tion generally showed levels of 0.01 to 0.04 mR/hr.
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