ML20083N376

Interim Deficiency Rept U-78 Re Failure of Chemetron Check Valve During Discharge Testing of Halon Fire Protection Sys. Initially Reported on 840319.Failure Under Evaluation. Defected Valves Being Replaced.Next Rept by 840514

ML20083N376
Person / Time
Site:	Callaway
Issue date:	04/10/1984
From:	Schnell D UNION ELECTRIC CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
U-78, ULNRC-793, NUDOCS 8404190170
Download: ML20083N376 (2)

Text

r, 4 -.

5 )/Y) b UNION ELECTRIC COM PANY 1901 GRATIOT STREET sT. Louis. MISSOURI oo~.co ,.sc~~ cc April 10, 1984 "^R'"*,'ff,"ff

• v.c. m....ea.o sr. i.ouis. unssoune es sea Mr.' James G. Keppler Regional Administrator U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 ULNRC- 7 93

Dear Mr. Keppler:

INTERIM 10CFR50. 55 (e) REPORT U-78 HALON F1RE PROTECTION SYSTEMS CHEMETRON CHECK VALVE FAILURE CALLAWAY PLANT On March 19, 1984 Union Electric reported a potential significant deficiency in accordance with 10CFR50.55(e) re-garding a Chemetron No. 1-061-0732 check valve which failed during discharge testing of a Halon Fire Protection System.

As was reported, the spring seat fractured and broken parts became lodged in a selector valve during system discharge.

The possibility exists that the broken parts could have lodged in.the selector valve and prevented full closure of the selector _ valve after discharge. Since the selector valves serve to direct the halon charge to the area experi-

.encing~a fire,. incomplete closure could result in insufficient halon concentrations on subsequent discharges. The spring seats of all 64 Chemetron check valves installed have been inspected and 14 have been found to have similar defects.

Union Electric has concluded that this failure is reportable as a significant deficiency in accordance with 10CFR50.55(e).

This failure is currently being' evaluate'd with the vendor,-and at this time it appears that valves of modified design will.be provided. In the interim, defective valves will be replaced and upon completion of each test the check-valve.will be inspected to verify its integrity. Failure of the checkovalve spring. seat will-not have any significant adversefeffect on first time discharge capability,~only on subsequent discharges if loose parts would become lodged in s

$$41Eclo's@olsa APR131984

.- PDR ,[/[

t ..8 -.

_ 2:ER7

(- , . .

5 a selector valve as described above. Until this matter is resolved, Halon Systems will be tagged with instructions to verify check valve integrity subsequent to any system dis-charge.

We will provide another report on this matter by

'May 18, 1984.

Very truly yours,

},

u .

9 gt Do ald F. Schnell PBD/jm ,

cc: B. L. Forney, Region III Richard DeYoung, Director I&E Bruce Little, NRC Resident Inspector John.Neisler, NRC Resident Inspector Missouri Public Service Commission i .- s t,

4 m

+

r G

._------.-.---..--____-__N--_-----_----_-----..__

'