ML20206G426

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SER Supporting Employee Concern Element Rept Co 10603, Bolting Matl Compatibility
ML20206G426
Person / Time
Site: Sequoyah  Tennessee Valley Authority icon.png
Issue date: 11/04/1988
From:
NRC OFFICE OF SPECIAL PROJECTS
To:
Shared Package
ML20206G037 List: ... further results
References
NUDOCS 8811220275
Download: ML20206G426 (2)
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Text

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/ ps n < .y'e UNITED STATES i i .,. j( ,': NUCLE AR REGULATORY COMM!SSION wassiNoToN. o. c. nosss 3 . / ,

s m .~. . V,.-l SAFETY EVALUATION REPORT SY THE OFFICE OF SPECIAL PROJECTS ,

EPcLOYEE C0hCERN ELEMENT REPORT C0 10603, "BOLTING MATERIAL COMPATIBILITY l TEhNES$rt VALLEY AUTHORITY  :

SEQUOfAH NUCLEAR FChER PLANT UNITS 1 & 2 i

00CKET hCS. 50 327 AND 50-328  ;

1. Subject i l

Categcry: Construction (10000)  !

j Sutcategory: Ec1 ting (10600) [

4 ,

j Element: Bolting Material Compatibi'ity (10603) [

3 i Employee Concerns: IN 86-183-001, IN-80-021 x04, and IN-85-824-001 l  :

i The basis for Element Report C0 10603-SQN, Rev. 3, dated December 19,  !

1926 is Watts Bar Employee Concerns IN-86-183 001, IN 85-021-XO4 and  !

IN-r~-e44-001, whien state (respectively):

i 1 "WENP Unit a stainless steel valves (check, globe and gate valves; j

different si:es; 2"O and up) have stud bolts & nuts should be stain- i l 1ess steel. In 1983 and 1984, steamfitters started '.o change out these carbon steel studs and nuts, the chnee out was stopped in 1984

)l before all the valves were templeted. Valves with carbon steel studs l i

) & nuts are now .nsulated. Location: Reactor Building, (Accumulator  ;

4 Rooms) and Aux Building Unit 1. CI could not m all system or valve ,

I numbers."

l i

"Unit 1 "all over" - stniinlets steel valves installed with carbon l steel studs that have since bet.i covered o,er with insulation. No additional information available."

Carton steel bolts are installed in stainless steel flanged connec- l tions. An enample of this can be found in Unit 2 in the Aux Building i g elevation 713' near 13 & 14 and U. Ge about 10' to tne north do.n  !

hall to a room on the left. An example is atout 3' off the floor en f

so e 6" pipe. It exists all over the plant. CI has no additional information. Const Dept. concern."

l

t*rtt O' trese cc9:eens =ere e.alsated ty TVA as not being nuclear safety-related ano tein, potentially applicable t: Se:;uoyan (generic).

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3 . .

These concerns were previously evaluated by TVA's Nuclear Safety Review j i Staff (NSRS) as potentially nuclear safety related and re-evaluated by the i TVA Employee Concern Task Group (ECTG) subsequent to completion of their l

evaluations as not nuclear safety related. The basis for this re evalua-l tion is industry experience indicating that leakage of bolted connections i cue to boric acid wastage of carbon steel bolts will be detected prior to i a significant loss of the pressure boundary, i

I  !!. Sum ary of Issue:

The problem as defined by TVA is that carbon steel be'.ts which were installed in stainless steel flantid connectic,ns (including valves), in

{ borated water systems, are rutting and need to be replaced.

j 111. Evaluatie u TVA ECTG personnel reviewed Nuclear Safety Review Staff (N$RS)

Investigation Report I-SS-483 IN (for Employee Concern IN 86-183 001),

TVA cesign documents ane vendor drawirgs and interviewed other TVA person-nel; they concluded that the use of carbon steel bolting in stainless steel flanged connections was common at Sequoyah, as well as Watts Bar, i

except in ASME Class I (TVA Class A) systems. The evaluation concluded

}

that the carbon steel bolting in boric acid systems should, and is, being replaced. TVA is implementing corrective actions to enhance the identifi-cation of flanged connections in borated water servic u and to replace i carbon steel bolts with stainless steel bolts in those connections.

l I IV. Conclusien:

3 . NRC inspectors revie ed Element Report C0 10603-SQH. Rev. 3, the TVA Jployee Concern Task Grcup (ECTG) file, and discussed the issue with j Sequoyah personnel,

(

j the NRC inspectors discussed with the ECTG evaluator the reclassification of the Employee Concerns. Although t,he NRC inspectors do not agree that 1

these Employee Concarns are not nuclear safety-related, the re evaluation was performed by the ECTG in conformance with ECTG Procedure M.1 l

( Attachment H), and did ' tot affect their evaluation of the issue or the correctise action.

The NRC staff concludes that TVA's investigation and resolution of the concern described in Element Report CO 10603 SQN, Rev. 3 was adequate.

The impletentation of the corrective action, which is not a restart item, should be werified in a future NRC inspection, 1

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