ML19261F247

Nonroutine 30-Day Rept 74-01 Re 741006,08 & 10 Unplanned Releases of Radioactive Gas in Reactor Coolant & Miscellaneous Waste Evaporator Rooms.Caused by Variance from Performance Specs.Sealing & Checking Under Way

ML19261F247
Person / Time
Site:	Three Mile Island
Issue date:	11/08/1974
From:	METROPOLITAN EDISON CO.
To:
Shared Package
ML19261F240	List: ML19261F239 ML19261F247
References
74-01, 74-1, NUDOCS 7910250672
Download: ML19261F247 (2)

Text

.

ENCLOSURE

. Metropolitan Edison Company Three Mile Island Nuclear Station, Unit 1 (IMI-1)

Docket No. 50-289 Operating License DPR-50 Nonroutine 30-Day Report 74 -01 Notification of a Variance from Perfor=ance Specifications

1. Description of Variance:

On October 6, 8, and 10,1974, there occurred four unplanned releases of radioactive gases in the Reactor Coolant and Miscellaneous Waste Evaporator Rooms at TMI-l (see Nonroutine 10-Day Reports 74-02, 03, and 04 and the associated 30-day report dated October 24, 1974).

These gases were then dispersed to other areas of the Auxiliary Building by the Auxiliary and Fuel Handling Building Ventilation System. The fact that these gases were so dispersed is contrary to the design function of the ventilation system as described in Subsection 9.8.2.f of the TMI-l FSAR. Specifically, it is stated in the FSAR that supply and exhaust duct systems are designed to direct the air furnished by the supply units in the Auxiliary and Fuel Handling Building from areas of low to areas of higher activity.

In the case of the four unplanned releases referred to above, this flow direction was not always maintained.

The above referenced variance can be attributed to several factors which caused decreased and/or gave rise to unbalanced and reversed air ficws in the Auxiliary and Fuel Handling Buildings; and these factors are as follows:

a. dirty air filters and intake grills

b. unsealed penetrations in the walls of the Auxiliary Building

c. two damaged automatic control dampers

d. poor control being provided 'by the static pressurizer controllers for the two damaged automatic control dampers

e. an inoperative Fuel Handling Building Exhaust Control

2. Corrective Action:

The following actions either have been or will be taken to correct the situation described above:

a. All air :11ters in the affected ventilation system and all intake grills to the exhaust duct work have been cleaned.

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b. A program to seal the penetrations in the Auxiliary

, ' - Building will be implemented,

c. A complete check of the static pressurizer controllers which are providing poor control will be conducted.

d. A recently begun program to check all mechanical components will be completed.

e. All system setpoints will be checked and verified.

f. Once the penetrations have been sealed and the operations of the static pressure controllers has been improved, a ventilation contractor will be called in to balance the systems and to insure that the design intent of the FSAR is being met.

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