ML17252A849

Letter Regarding an Occurrence Where Both Doors of the 80 Foot Elevation Personnel Air Lock to the Containment Building Were Inadvertently Opened at the Same Time for About Thirty Seconds - Indian Point Unit 2

ML17252A849
Person / Time
Site:	Indian Point
Issue date:	02/06/1974
From:	Cobean W Con Edison, Consolidated Edison Co of New York
To:	O'Reilly J US Atomic Energy Commission (AEC)
References
Download: ML17252A849 (2)

Text

... ,_,on Company of New York, Inc.

i. Irving Place. New York, NY 1000,3 6 February 1*9 7 4 Re: Indian Point Unit No. 2 Facility Operating License DPR-26 A.0.-4-2-7 Mr. James P. O'Reilly, Director Regulatory Operations, Region I

u. S. Atomic Energy Commission "631 Park Avenue 50-247 Kirig of Prtissia, Pennsylvania 19406

Dear Mr. O'Reilly,

On F~bruary 1, 1974 at approxim~tely 3:50 PM both doors of the 80 foot elevation personnel air lock to the containment build-ing were inadvertently opened at the same time for a period of about thirty seconds. At the time of this occurrence, the reactor was shutdown with all full length control rods fully inserted in the core. The reactor coolant system pressure and temperature were 2235 psig and 5400F respectively, and the reactor coolant bor-ic acid concentration was approximately 1190 ppm. boron. With this concentration of boron and all control rods fully inserted*, the reactor was subcr i tic al by more than 7 percent <l k/ k.

Investigation into the cause of the occurrence revealed the following pertinent information:

Whenever the plant is n6t in the cold shutdown condition and contai*nment entry is to be made by other than operating per-sonnel~ a man who has b.een properly instructed on the opera-tion of the air lock doors and the requirements for contain-ment integrity is stationed in the airlock to operate its controls. In addition, signs are posted at the outside of each door to info~m plant personnel when system conditions are such that containment integrity is required' At about 3:50 PM on February 1, 1974,*an offsite Company em-

. ployee in at~empting to ente~ containment fr6m outside the air lock mistakenly operated the wrong hand wheel opening

• the inner air lock door. Both the operator stationed inside the air lock and the person_outside realized what happened

• ,::;\

(

. **.J. 6 February .1974 and both started to close th~ inner door. Upon closing, the inner door bOun*ced off its seati,ng frame and the door latch rotated into position with the inner door ~till open. When the individual outside the iirlock noted the

~rroneous inditation that the inner door was closed, he immediately started opening the outer door. Before the operator inside the airlock could stop its movement, and reclose the door, containment integrity had been breeched for about thirty seconds.

We are continuing our investigation into this matter and will advise you of our findings and corrective action taken to prevent recurrence. Mr. Anthony Fasano of your office was no-tified of this occ~rrence on Februaiy 2, 1974 by Mr. John Make-peace ..

Very truly yours, I *~ \ . *

\_}-) w\hQ..\t\

'U i .

r_, ~JDl;lliJ--"v\..

f) \ ~j Warren R. Cobean, Jr.

Manager, Nuclear Power Generation

• cc: Mr. John F. O'Leary-