Information Notice 1979-26, Breach of Containment Integrity

Breach of Containment Integrity

ML031180182
Person / Time
Site:	05000000
Issue date:	11/05/1979
From:	NRC/IE
To:
References
IN-79-026, NUDOCS 7908220133
Download: ML031180182 (4)

SSINS: 6870

Accession No:

7908220133 UNITED STATES

NUCLEAR REGULATORY COM4ISSION

OFFICE OF INSPECTION AND ENFORCEIENT

WASHINGTON, 0. C. 20555 November 5, 1979 IE Information Notice No. 79-26

Description of Circumstances

On September 14, 1979, the Consumers Power Company (CPC) notified the NRC of

discovery at the Palisades Nuclear Generating Plant of a valve misalignment that

had resulted in containment integrity being breached for an indeterminate length

of time.

While preparing to perform a Type "C" leak test between two manual valves in a

3" bypass line around the main 48" containment ourge valve, plant personnel dis- covered that both of these manual isolation valves were locked in the open posi- tion. These valves should have been locked closed. Investigation by the licensee

indicated that the valves may have been improperly positioned since April, 1978, when an efficiency test of the bypass line filters was performed. The plant has

operated at power for the major portion of that time period.

The valve misalignment had no actual impact on the public health. However, in

the event of a desimn basis accident wherein fuel damage and release of primary

coolant inside the containment are postulated, the open valves would provide a

significant oath for a radioactive release from the containment.

The initial design purpose for the bypass system was to provide a long term

hydrogen control capability for the containment atmosphere following a design

basis accident.Y It was intended that after approximately 30 days following

an accident, when containment pressure and activity levels dropped sufficiently

to permit venting, this system would be manually valved to vent the containment

atmosphere, through high efficiency and charcoal filters, to the exhaust stack.

Thus the components in the bypass line beyond the two manual isolation valves

were not designed for the severe service they would be exposed to with the valves

ooen during the initial pressure surge of the desian basis accident, and signif- icant uncontrolled release would result. High radiation in the vicinity of the

bypass line would also make immediate closing of the manual isolation valves, even if identified as the source of leakaae, an extremely hazardous operation.

The principal cause for this event was inadequacy of the procedures addressing

proper use and oositioning of these valves. The master containment integrity

valve line-up checklist, which is performed prior to each startup from cold

1/ Current MRC requirements call for the use of hydrogen recombiners to control

Rydronen builduo. Palisades has recombiners installed.

IE Information Notice No. 79-26 November 5, 1979 Paqe 2 of 2 shutdown, did not include these valves. The filter efficiency test for the 3"

bypass line did not adequately specify the final oosition of these valves, and

this is the orobable cause for the valves being left incorrectly positioned.

The valve misalignment represents a case where human factors in the form of

inadequate procedures resulted in a loss of safety system function.

CPC has undated the above mentioned procedures to assure that orooer positioning

of these valves is addressed. Concurrently, CPC is reviewing other paths from

containment to assure that procedures and checklists are complete. CPC has also

hired a qualified consultant to perform an independent review for the same

purpose.

This Information Notice is provided as an early notification of a significant

occurrence. It is expected that recipients will review the information for

possible applicability to their facilities. No written response is required.

If you desire additional information regarding this matter, contact the Director

of the aoDropriate MRC Regional Office.

IE Information Motice No. 79-26 Enclosure

November 5, 1979 LISTING OF IE INFORMATION NOTICES

ISSUED IN LAST SIX MnNTHS

Information Subject Date Issued To

Notice No. Issued

79-14 NRC Position of Electrical 6/11/79 All Power Reactor

Cable Support Systems Facilities with a

CP

79-15 Deficient Procedures 6/7/79 All Holders of Reactor

OLs and CPs

79-16 Nuclear Incident at Three 6/22/79 All Research Reactors

Mile Island and Test Reactors

with OLs

79-17 Source Holder Assembly Damage 6/20/79 All Holders of Reactor

Damage From Misfit Between OLs and CPs

Assembly and Reactor Upper

Grid Plate

79-18 Skylab Reentry 7/5/79 All Holders of Reactor

OLs

79-19 Pipe Cracks In Stagnant 7/17/79 All Holders of Reactor

Borated Water Systems At OLs and CPs

PUR Plants

79-20 NRC Enforcement Policy 8/10/7'9 All Holders of Reactor

NRC Licensed Individuals OLs and CPs and Production

Licensees with Licensed

Operators

79-21 Transoortation and Commercial 9/7/79 All oowier and research

Burial of Radioactive Material reactors with OL's

79-22 Oualification of Control 9/14/7'9 All oower reactor

Systems facilities with

noeratina licenses

and construction permits.

79-23 Emergency Diesel Generator 9/25/79 All Dower reactor

Lube (Oil Coolers facilities holding OLs

and CPs

I.

• IEInformation Notice No. 79-26 Enclosure

November 5, 1979 LISTING OF IE INFORMATION NOTICES

ISSUED IN 1979 Information Subject Date Issued To

Notice Mo. Issued

79-24 Overoressurization Of 9/28/79 All ow er reactor facilities

Containment Of A PWR Plant with a CP

After A Main Stream Line

Break

79-25 Reactor Trips At Turkey 10/1/79 All cower facilities with

Point Unit 3 And 4 an OL or a CP