ML20070U606

Interim Deficiency Rept Re Configuration of Impulse Tubing Allowing for Potential Undrainable Condensate Accumulation. Caused by Downward Slope of Primary Containment Instrument Line.Tubing Containment & Sensing Lines Modified

ML20070U606
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	01/28/1983
From:	Milligan M LONG ISLAND LIGHTING CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, SNRC-829, NUDOCS 8302100427
Download: ML20070U606 (2)

Text

-

1 1

l a

y== _ =n.

I LONG ISLAND LIGHTING COMPANY l 1

] SHOREHAM NUCLEAR POWER STATION

.s <mmmww.semumM P.O. BOX 618, NORTH COUNTRY ROAD + WADING RIVER, N.Y.11792 Direct Dial Number January 28, 1983 SNRC-829 Mr. Ronald C. Haynes Office of Inspection and Enforcement, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 LONG ISLAND LIGHTING COMPANY SHOREHAM NUCLEAR POWER STATION - UNIT 1 DOCKET NO. 50-322

Dear Mr. Haynes:

On December 30, 1982, in accordance with 10CFR50.55 (e) , we reported verbally to Region I a reportable deficiency involving converse instrument line slopes for those instruments which sense the primary containment atmosphere pressure. Our engineering review of this condition has been conpleted and the appropriate corrective actions initiated. Therefore, this letter will serve as our 30 day written report pertaining to this deficiency.

Description of Deficiency During a routine inspection by LILCO's Independent Safety Evaluation Group (ISEG) a condition was discovered whereby a configuration of impulse tubing for certain primary containment atmospheric sensing lines allows for the potential of undrainable condensate accumulation. The problem with the subject lines evolves from the condition that every Primary Containment instrument line penetration plate has the lines sloping down in the outward direction. In the Secondary Containment, the outer end of the penetration pipe mates with the instrument line which, according to specification, must slope up towards the instrument. As a result, approximately seven feet of the instrument line slopes down (Penetration pipe) and the remaiping instrument line slopes up,. This condition provides a low p int (which is not drainable) of approximately eight inches in ight.

If this low point should fill with condensation, a pocket of water or " loop seal" would develop. Pressure pulses wou , still be transmitted to the transducer, however the resultant signal would be erroneous, variable, and delayed all in a non-conservative direction. This condition cannot be " calibrated 8302100427 830128 PDR ADOCK 05000322 7 s PDR g6

. o SNRC-829

, January 28, 1983 Page # 2 out" and is not tolerable because the lines are for the numerous pressure transmitters required for RPS and ECCS functions. The condition, had it remained uncorrected, would be expected to result in higher than allowable pre-LOCA pressure, delays in SCRAM initiaton, and erroneous containment pressure indication in the control room.

Corrective Action Our corrective action involves installation of self-draining tubing configurations, activation of four spare containment penetrations, and review of all other atmosphere sensing lines from the Primary Containment. The required modifications are currently being implemented according to CCF Ell /19 and E&DCR P-4305. The engineering documents referenced are reflective of only the four instrument lines cited by LILCO's ISEG team. The review of all other atmospheric sensing lines has been completed by Stone & Webster and the resultant conclusion is that there are no other lines with this problem. Specifically, all other lines are either heat traced, self-draining, equipped with moisture separators or configured such that moisture condensation possibilities are extremely remote and would result in a conservative error. Therefore, no other modifications are required. This work will be completed by April 30, 1983.

Very truly yours, e-c$'

M. H. Milligan Project Engineer Shoreham Nuclear Power Station BWC/spg cc: Mr. Victor Stello, Director NRC Office of Inspection and Enforcement Div. of Reactor Operations Inspection Washington, D.C.

Mr. J. C. Higgins USNRC Resident Inspector NRC Site Office (TSC)

All Parties