ML20093N898

Proposed Tech Spec SR 5.3.12, Steam Generator Tube Leaks Surveillance

ML20093N898
Person / Time
Site:	Fort Saint Vrain
Issue date:	10/12/1984
From:	PUBLIC SERVICE CO. OF COLORADO
To:
Shared Package
ML20093N887	List: ML20093N884 ML20093N892 ML20093N898
References
NUDOCS 8411060036
Download: ML20093N898 (4)

Text

{{#Wiki_filter:7e 7 . Fort St. Vrain #1

4. . Technical Specifications

                  .                                                                Amendment N3.

Page 5.3-22

2

                      .l7         Specification SR- 5.3.12' - Steam Generator Tube Leaks p;                     :l         -Surveillance-ll       ;Following:each steam generator tube leak, specimens from l~        the accessible subheader tubes connected to the leaking
                      -l'         inaccessible tube (s) shall be metallographically examined.

l_ -The results of this examination shall be compared to the

                                                    ~
'E
                      -l.         results from the specimens of_all previous tube leaks.

l

                                 -A  study -shall be performed to evaluate the size and l          elevation of all tube leaks to determine if a cause or

[ trend in the degradation of the tubes can be identified. l -Following each steam generator tube leak study, the

                      .]          Nuclear Regulatory Commission shall be notified as to the
                      -l          estimated size and elevation'of the leaks as well as the

, l results of the metallographic and engineering analyses t l performed .that may_ identify the mechanism that caused the l leak to occur.

j. Basis for' Specification SR 5.3.12 l During the life time of the plant a certain number of

                     'l.          steam generator tube leaks are expected to occur, and the l          steam generators have been designed to have these leaking
                     .- l         tube subheaders plugged without affecting the plant's
                     ~j        ' performance     as    shown        .in        FSAR         Table 4.2-5.                  The l          consequences of steam generator tube leaks have been l          analyzed in FSAR Section 14.5.
        ~'

9411060036 841012 PDR-ADOCK 05000267 P PDR

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be.S[ fg > Fort St..Vrain #1 . 4 Technical-Sptcifications 4-  ; Amendment No. y Page 5.3-23 9

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                                                                  ~It~Lis':important~. to. identify the size ~and elevation of Ll. '                     ' steam -generator : tube leaks and to metallographically
      t                               ~l:                      . examine _     the   subheader' tube           material because this
&p" '

l:. information'can be used to identify any trend or generic yl.

                                       .:                       :cause ~     of tube- leaks.       Conclusive identification of the l)                        cause of:Ja. steam generator. tube 11eak                will   enable
             ~                      '
                                        -l'.                       modifications _ and/or changes in operation to increase-the .

il reliability s and life of 'the ~ steam generators and to lp'revent': tube sfailures31n' excess of those analyzed in:the

ll

[ll FSAR.

    .                                                                                                                  7
                                                                           ~
                                       . l .l                  'Because of the subheader designs leading to the steam
                                        -{.                       generator's tube bundles,          in-situ internal -or external
    .                                  ;l                       -inspection and- evaluation of a tube leak to establish a

l. . conclusive cause is not practical. 'Metallographic-

                                       .l'                        examination of the. accessible conn ~e cting subheader tube
                                       -l                         will show the condition of the internal subheader wall,
                                       ~l.                        giving an indication of the conditions of the leaking tube
                                       -ll                        internal.' wall, thereby demonstrating the effectiveness of             "
                                       ,[-                       water chemistry controls. Determining the exact size-and
                        ,             -l                      _ elevation of the tube leak wil1~ enable evaluation of other jl:                     ;possible leak causes such as tube / tube support plate
      ;6'
                                       ~l                         interface effects.

7 m

      ??                  . . . .

W l- ., The. surveillance' ' plan outlined above is considered (l' ' adequate to evaluate steam generator tube integrity and [ L l .C assure that~ the . consequences of postulated tube leaks remain within the limits analyzed in the FSAR.. l, y'

                       ~                                                                       ,

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3e i A ATTACHMENT E f SIGNIFICANT HAZARDS CONSIDERATIONS t , .

                         .t f'

s N. .4

3 4 1._ l SIGNIFICANT HAZARDS CONSIDERATIONS I; EVALUATION SR 5.3.12

                 .The addition :of this surveillance requirement will assure that the appropriate examination, analysis, and Nuclear Regulatory Commission -notification requirements, as committed in P-84028, will be performed following any future tube leaks. The described

program is considered adequate to evaluate steam generator tube

                  ' integrity _and maintain the consequences of postulated tube leaks within the limits analyzed in the FSAR.

II. CONCLUSION ~ Based on the above evaluation, it is concluded that operation of

                 -Fort St. Vrain in 'accordance with the proposed changes will not(1) involve a significant increase in the' probability or consequences'of an accident previously evaluated, (2) create the possibility of a new or different kind of accident from any accident. previously evaluated, or (3) involve _a      significant L                   reduction in any margin of safety.
                 'Therefore, these changes will not increase the risk to the health and safety of the public-nor do they involve any significant hazards considerations.}}