ML20236V145

PN-75-114:measurements of Radiation Levels Inside Containment During Low Power Physics Test Program Confirmed That Radiation Streaming Problem Similar to That Identified at Calvert Cliffs,Unit 1,exist at Plant,Unit 2

ML20236V145
Person / Time
Site:	Millstone
Issue date:	10/29/1975
From:	Jennifer Davis, Dreher F, Thornburg H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PN-75-114, NUDOCS 9807310328
Download: ML20236V145 (1)

Text

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-PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE October 29, 1975 I .C.:.

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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE --PN-75-114 p

i This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information presented is as initially received without verification or evaluation and is basically all that is knotrn by OIE staff as of 8:00 a.m. on the date of this notification. IT SHOULD BE SPECIFICALLY NOTED THAT THIS i

NOTIFICATION MAY CONTAIN INFORMATION THAT LATER MAY BE DETERMINED TO BE INACCURATE OR INCONSISTENT. AN OFFICE OF INSPECTION AND ENFORCEMENT NOTIFICATION OF AN INCIDENT OR OCCURRENCE (BLUE SHEET) SUBSEQUENTLY l

VILL BE ISSUED IF WARRANTED. I

. .. _, Facility: Millstone Point Unit 2 (DN 50-336)

Northeast Nuclear Energy Company l

i

Subject:

INSUFFICIENT REACTOR SHIELDING >

L l

Measurements of radiation levels inside containment during the low power '

I physics test program have confirmed that a radiation streaming problem l similar to that identified at Calvert Cliffs 1 exists at Millstone Point 2. l Measurements made inside containment at 10-2% power revealed levels of 2

.175 MREM /hr above the reactor vessel and in the reactop coolant pump '

cubicles with levels of 25 MREM /hr in the general area. Measurements ll=3 )

made-outside containment at the same power level revealed background ,

3 levels. [

i - ,

This problem was anticipated by the licensee and NRR. A radiation i

measurement progr.t.m is being implemented in accordance with the NRR f Safety Evaluation Report, Supplement 2. The results of this progrem i will be reported to NRR.

Media interest is expected because of the press attention given to this problem when it occurred at Calvert Cliffs 1. The State of Cotmeeticut has been and is being kept informed. A press release i

is not planned.

r j OIE received notification of this occurrence by telephone from Mr.

f Counefl, Plant Superintendent, at 12 10 p.m., October 24, 1975.

I

Contact:

FADreher, IE x7261 HDThornburg, IE x 7353 JGDavis, IE x7541 Distribution:

Chaignen Anders -

Commissioner Mason S. J. Chilk, SECY Commissioner Gilinsky Commissioner Rowden G. F. Murphy, 3CAE Commissioner Kennedy C. C. Kammerer, CA f I

L. V. Gossick, EDO D. F. Knuth, IE J. A. Harris' PA ,

B. C. Rusche, NRR J. La Fleur, ISP T. J. McTiernan, AIA K. R. Chapman, NMSS H. K. Shapar, ELD ty \;, Transmitted: P Bldg 9 W-; H St fd0w ; MNBB 8 M ; Lugep id 1

PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE l 9807310328 751029 1 i PDR ItsE $ 4 PN-75-114 PDR {