Information Notice 1979-26, 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
BREACH OF CONTAIMNENT INTEGRITY
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
November 5, 1979
LISTING OF IE INFORMATION NOTICES
ISSUED IN LAST SIX MnNTHS Information
Notice No.
79-14 Subject
Date
Issued
Issued To
NRC Position of Electrical
Cable Support Systems
6/11/79
All Power Reactor
Facilities with a
79-15
Deficient Procedures
Nuclear Incident at Three
Mile Island
6/7/79
All Holders of Reactor
79-16
6/22/79
All Research Reactors
and Test Reactors
with OLs
79-17 Source Holder Assembly Damage 6/20/79
Damage From Misfit Between
Assembly and Reactor Upper
Grid Plate
All Holders
of Reactor
79-18
Skylab Reentry
7/5/79 All
Holders of Reactor
79-19
Pipe Cracks In Stagnant
Borated Water Systems At
PUR Plants
7/17/79 All Holders
of Reactor
79-20
79-21 NRC Enforcement Policy
8/10/7'
NRC Licensed Individuals
Transoortation and Commercial 9/7/79
Burial of Radioactive Material
Oualification of Control
9/14/7'
Systems
9/25/79 Lube (Oil Coolers
9
All Holders of Reactor
Licensees with Licensed
Operators
All oowier and research
reactors with OL's
9
All oower reactor
facilities with
noeratina licenses
and construction permits.
All Dower reactor
facilities holding OLs
and CPs
79-22
79-23
I.
- IE
November 5, 1979 LISTING OF IE INFORMATION NOTICES
ISSUED IN 1979 Information
Notice Mo.
Subject
Date
Issued
Issued To
79-24
79-25
Overoressurization Of
Containment Of A PWR Plant
After A Main Stream Line
Break
Reactor Trips At Turkey
Point Unit 3 And 4
9/28/79
All ow er reactor facilities
with a CP
10/1/79
All cower facilities with