ML20151Y350

PNO-77-163:on 770918,waste Gas Tank Rupture Disc Failed While Tank Was Being Filled,Resulting in Monitored,Unplanned Release of Radioactive Material Environment.State of Connecticut Informed.Licensee Plans to Notify Media

ML20151Y350
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	09/19/1977
From:	Flack E, Higginbotham L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-77-163, NUDOCS 9809180209
Download: ML20151Y350 (1)

Text

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_Q {}(( C<)VMLU Q1 f ] /2 AV}" V PRELIMINARY NOTIFICATION i September 19, 1977 .

l i

PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-77-163 !

This )reliminary notification constitutes EARLY notice of an event of

' I" '

' POSSI3LE safety or public interest significance. The information presented is as initially received without verification or evaluation 1 i

and is basically all that is known by IE staff on this date.

! Facility: Connecticut Yankee Atomic Power Company HaddamNeckPlant(DN50-213) l Haddam Neck, Connecticut

Subject:

UNPLANNED RELEASE OF RADI0 ACTIVE MATERIAL At 5:10 a.m., on September 18, 1977, a waste gas tank rupture disc failed while the tank wes being filled, resulting in a monitored, unplanned release of radioactive material to the environment. The release was secured at 5:21 a.m., by isolating the tank.

1 The release consisted of isotopes of Xenon, Krypton, and Argon. The l

' maximum release rate of 11,300 microcuries per second exceeded the '

. Technical Specification allowable rate for this mixture of 9,960

microcuries per second. Only one isotope Xe-133, exceeded the 10 CFR..

gmj g 20concentrationlimitof3x10-7myrocu,riespercubiccentimeterwith an actual concentration of 3.22 x 10 microcuries per cubic centimeter -

Total activity released was 7.44 Curies Cp f

Media interest is expected because of close attention given to releases 2) of radioactive material to the environment. The State of Connecticut A: '

has been informed. The licensee plans to notify news media today. O

+

, NRC, Region I, (Philadelphia) received notification of this occurrence d by telephone from the Assistant Plant Superintendent at 3:30 p.m.,

%m September 18, 1977. This information is current as of 8:30 a.m._,

_g September 19, 1977.

-Contact: EDFlack, IE x25188 LBHigginbotham, IE x27347 I Contact

$ 6fstribution: Transmitted H St 12.lo0; p tiairman Hendrie Commissioner Bradford Comissioner Kennedy S. J. Chilk, SECY C. C. Kammerer, CA Q Commissioner Gilinsky -

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W. G. Mcdonald, MIPC C. V. Smith, NMSS R. G. Ryan, OSP R. J. McTiernan, 0IA H. K. Shroar_ n n R. Minogue, SD PRFlIMINaDV NATiritTrinu

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