ML19261F305

Nonroutine 30-Day Environ Rept 74-01:on 740824-31,radiation Level of Air Particulate Sample Reached More than Four Times Control Station Valve.Source Believed to Be Other than TMI, Possibly Chinese Nuclear Bomb Detonated 740617

ML19261F305
Person / Time
Site:	Three Mile Island
Issue date:	10/04/1974
From:	METROPOLITAN EDISON CO.
To:
Shared Package
ML19261F304	List: ML19261F303 ML19261F305
References
NUDOCS 7910250768
Download: ML19261F305 (1)

Text

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E?IClCSURE Metropolitan Ediscn Cc=pany Three Mile Island IIuclear Staticn, Unit 1 (TMI-1)

Decket Iio.50-28c Operating License IIc. OFR-50 IIcnroutine 3C-Eay Environmental Repcrt Th-01 Iatificaticn of an Anc=alcus Measured Level of Radiatica

1. Descriptica cf Occurrence:

An air particulate sample collected 2500 feet SSE of the Reactor Suilding for the period August 2h-31, ic7h, showed a beta cencentration of 5 2 x 10-13 uCi/=1, which was 9.6 times the beta concentration for the control statien. An i==ediate investigation was begun to determine the source of radienuclides that caused this increase.

2. Apparent Cause cf Occurrence:

c the following reasons it is believed that the anc=alcus measured level of radiation rader discussion resulted frc= a scurce other than TMI-1.

a. Analyses indicate that if the neasured radiaticn levels had resulted frc= ther=al neutron fissioning of U-235 atc=s, the fissions vould have had to cecur prior to the date cf initial TMI-l reacter criticality,

b. Analyses also indicate that the measured radiation levels de correspcnd with these that vculd have been expected frc=

the Chinese nuclear be=b detonatien cf June 17, 197L.

c. Most of the measured beta activity was restricted to one quadrant of the filter paper, which is =cre indicative cf a single stray het particle vice a release frc= TI!!-1.

d. The high gross beta activity was restricted to only cne sample station, which again is =cre indicative cf a single stray hot particle vice a release frc TMI-1.

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