ML20010B389

Interim Deficiency Rept Re Misapplication of Marotta Excess Flow Check Valves in Primary Containment Instrument Sensing Lines,Originally Reported on 810702.Caused by Inadequacies in Valve Specs.Also Reportable Per Part 21

ML20010B389
Person / Time
Site:	Susquehanna
Issue date:	08/07/1981
From:	Curtis N PENNSYLVANIA POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
REF-PT21-81 10CFR-050.55E, 10CFR-50.55E, PLA-901, NUDOCS 8108140430
Download: ML20010B389 (4)

Text

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Pennsylvania Power & Light Company -

Two North Ninth Street

• Allentown, PA 18101

• 215 1 770'5151 Norman W. Cuttis Vice President-Engineering & Construction-Nuclear 215 / 770-5381 August 7, 1981 I

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• r. Boyce H. Grier ,'* Od[ \

Lirector, Region I >

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U. S. Nuclear Regulatory Commission  ; ' #-

631 Park Avenue  ; O'/g[A 73 King of Prussia, PA 19406 Pe.

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SUSQUEHANNA STEAM ELECTRIC STATION G

INTERIM REPORT OF A POTENTIAL '2FICIENCY INVOLVING MISAPPLICATION OF MAROTTA EXCESS FLOW CHECK VALVES ERs 100450/100508 FILES 821-10/840-4 PLA-901

Dear Mr. Grier:

This letter serves to provide the commission with an interim report of a potentially reportable deficiency involving the misapplication of harotta excess flow check valves in primary containment instrument sensing lines.

The problem was originally reported by telephone to Mr. L. Narrow of NRC Region I by Mr. A. Sabol of PP&L on July 2, 1981. During that conversation, Mr. Narrow was advised that the condition was considered potentially reportable under the provisions of 10 CFR 50.55(e).

The attachment to this letter contains a description of the problem, its cause, safety implications and corrective action under consideration.

Since the details of this report provide information relevant to the reporting requirements of 10 CFR 21, this correspondence is considered to also discharge any formal responsibility PP&L may have in compliance thereto.

We expect ta issue a final report on the problem in October 1981. We trust the Commission will find this information acceptable.

Very truly yours,

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N. W. Curtis Vice President-Engineering & Construction-Nuclear FLW:sab Attachment I

8108140430 810807

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• I Mr. Boyce H. Grier August 7, 1981 cc: Mr. Victor Stello (15)

Director-Office of Inspection & Enforcement U. S. Nuclear Requiatory Commission Washington, D.C. 20555 Mr. G. Mcdonald, Director (1)

Office of Management Information & Program Control U. S. Nuclear Regulatory Commission

'4ashington, D.C. 20555 Mr. Gary Rhoads U. S. Nuclear Regulatory Commission P.O. Box 52 Shickshinny, PA 18655

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i Attachment to PLA-901 l

[ Subject

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- Misapplication of Marotta Excess Flow Check Valves -

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' ' Description of Potential Problem i'

i' Instrument sensing lines which penetrate the primary containment are equipped' with excess flow check valves. The purpose of these valves is to mitigate the L

consequences of a line break outside containment. Although some of the valves i are used in lines which sense containment atmosphere-(nitrogen) and possibly

- steam, the valves have been designed oecifically for water service. Because of the lower densities and viscosities ot nitrogen and steam, it is doubtful that

{ the subject. valves would close as intended when required to operate to prevent i the leakage of containment gases. These valves for Unit 1 are listed in Table ~I. .

Cause l

The causes of the deficiency were apparent inadequacies in the valve specifica-tion. The body of the specification had a general statement that fluids would

! be " water and steam." The valves were required to be tested with water only.

[' Some data sheets, which should have listed nitrogen / steam as.the fluid, incor-p 'rectly listed water. . Given these valve specification provision,s, Bechtel Engineering approved the vendor drawings, test procedure, and instruction manual for Marotta excess' flow check valves which may be suitable for water i' service only.

Analysis of Safety Implications L Under normal operating conditions the primary containment pressure will range

( from 0.1 to 1.5 psig. A line break would result in minimal leakage. However, during'a LOCA, the containment pressure could reach.43.8 psig. .The valves are-required to have a resistance to flow equivalent to a .375" diameter sharp edged orifice. As there are a total of sixteen valves in question on Unit 1, each-2 having an equivalent cross secticaal area of .11 in-, failure.of these valves to close could jeopardize contair aent integrity. The condition is potentially a significant deficiency in final design and therefore reportable under 10 CFR' 50.55(e).

l-b l- Corrective Action t

i Data is currently being obtained from the valve manufacturer to determine .the l pressures and flows' required-to close the valves using nitrogen / steam. On_the

! assumption that the valves may prove to be inadequate for the ' design requirements, I- Bechtel has initiated an investigation to determine the feasibility of upgrading I 'the sensing lines to ASME Section III' Class 2. This would'make the sensing. lines p

extensions of containment and permit the removal of the excess flow check valves.

Discussions with Bechtel will be held to assure that appropriate procedural changes.

g have been made to prevent recurrences of this type design problem.

I-Page 1 of 2

t Attachment to PLA-901

' Control of the subject Unit 1 valves is provided by PP&L NCR's #81-311, 312 and 313. Unit 2 valves will be controlled under the Bechtel program. Bechtel QA is currently working to identify all nonconforming valves within their jurisdiction and will provide Bechte] QC with information necessary to generate a Bechtel NCR on those valves.

TABLE I Excess Flow Check Valves Lo.Ated in Unit 1 Air Sensing Lines XV-15110A XV-15110B XV-15110C XV-15110D

! ,XV-15516 XV-15775A XV-15775B XV-15776 XV-15701A i

XV-15701B XV-15702A XV-15702B XV-15703A XV-15703B XV-15710A

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XV-15710B I

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