ML20147B456

Proposed Tech Specs Adding Third Special Interest Group of Steam Generator Tubes

ML20147B456
Person / Time
Site:	Davis Besse
Issue date:	01/11/1988
From:	TOLEDO EDISON CO.
To:
Shared Package
ML20147B433	List: ML20147B427 ML20147B444 ML20147B456
References
TAC-66736, NUDOCS 8801150240
Download: ML20147B456 (10)

Text

'

, l* / ef to

= '.

REACTOR COOLANT SYSTEM STEAM GENERATORS  :

LIMITING CONDITION FOR OP'ERATION 3.4.5 Each steam generator shall be OPERABLE with a water level between 18 and 348 inches.

APPLICABILIT'Y : MODES 1, 2, 3 and 4.

ACTION:

a. With one or more steam generators inoperable due to steam generator tube imperfections, restore the inoperable generator (s) to OPERABLE status prior to increasing T,yg above 200'F.

b. With one or more steam generators inoperable due to the water level being outside the limits, be in at least HOT STANDBY witnin 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

SURVEILLANCE REQUIREMENTS f 4.4.5.0 Each steam g nerator shall be demonstrated OPERABLE by perfortnance of the following augmented inservice inspection program and the requirements of Specification 4.0.5.

4.4.5.1. Steam Generator Samole Selection and Inspection - Each steam generator shall be determined OPERABLE during shutdown by selecting and inspecting at least the minimum number of steam generators specified in Table 4.4-1, 4.4.5.2 Steam Generator Tube Samole Selection and Inspection - The steam generator tube mi6imum cample size, inspection result classification, and the corresponding action required shall be as specified in Table 4.4-2.

The inservice inspection of steam generator tubes shall be perforced at the frequencies specified in Specification 4.4.5.3 and the inspected tubes shall n$g be verified acceptable per the acceptance criteria of Specification 4.4.5.4.

The tubes selected for each inservice inspection shall include at least 3%

i l

8 of the total number of tubes in all steam generators; the tubes selected l 20 for these inspections shall be selected on a random basis except:

Sd gg a. The first sample inspection during each inservict inspection n< (subsequent to the baseline inspection) of each sieam generator )

O shall include: l 88 maa l

1. All nonplugged tubes that previously had detectable wall  !

penetrations (>20".). ,

, 2. At least 50". of the tubes inspected shall be in those  !

areas where experience has indicated potential problems.

DAVIS-BESSE, UNIT 1 3/4 4-6 Amendment No.;1 1 I

~

SERik. No 58 pqe.cf to REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) *

3. A tube inspection (pursuant to Speci , a tion 4.4.5.4.a.8) ,

shall be performed on each selected woe. If any selected tube does not permit the passage of tne eddy current probe for a tube inspection, this shall be recorded and an adjacent tube shall be selected and subjected to a-

r. tube inspection,

b. Tubes in the following groups may be excluded from the first random sample if all tubes in a group in both steam generators are inspected. No credit will be taken for these tubes in meeting minimum sample size requirements.

1. Group A-1: Tubes within one, two or three rows of the open inspection lane.

2. Group A-2: Tubes having a drilled opening in the 15th support plate. +

3. ' hserL A *

c. The tubes selected as the second and third samples (if required by Table 474-2) during each inservice inspection may be subjected to less than a full tube inspection provided:

1. The tubes selected for these samples include the tubes from those areas.of the tube sheet array where tubes with imperfections were previously found.

2. The inspections include those portions of the tubes where imperfections were previously found.

The results of each sample inspection shall be classified into one of the following three categories:

Category Inspection Results C-1 Less than 5% of the total tubes inspected are degraded tubes and none of the inspected tubes are defective.

C-2 One or more tubes, but not more than 1% of '

the total tubes inspected are defective, or between 5% and 10% of the total tubes inspected are degraded tubes. ~

C-3 More than 10% of the total tubes inspected are degraded tubes or more than 1% of the inspected tubes are defective.

DAVIS-BESSE, UNIT 1 3/4 4-7 Amendment No. '21 ,

_ . _ . . _ _ _ _ _ . ._ . . _ . _ _ _ . _ ._. _ . ..._._ _ _ _ _ - -=_

5emm 1458 q 3 sf to l

s. .

o Tnseri .A. .. _ . ___ _ .. . . . . . _ . . _ . ._ __ _. ,

Lvoop . A.- 3 :...... Sobes -..inct ud ed in. th e . . < ec.t ang l .e _.. ._ -__ l

_ bouncLed _ by. rows._W and._90. a nd .. _by - to b e s _. ..~ _ .._, _ ._. i

. _ .5 8 and .7 fo . etciacung tobes . included _ in . ._ .... ._

Aroop A-1. . . _ . _ . .. __ _. _ _

M.

e i

I I

1

_o+. ..-

8 l

l l

'J l

9 t ,mrm e- 4 -'F-'ev v r' --*Y*= * '- - -- - * - - ' ,-+ - -+4*-*r'+wer=* ******-'r-r

• 4b HIS PAGE PROV DED REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued)

. Notes: (1) In'hil inspections, previously de must exhibit significant (> 10%) graded further tubes wall penetrations to be included in the above per-centage calculations.

(2) Where special inspections are performed pursuant-to 4.4.5.2.b, defective or degraded tubes fourd as a result of the inspection shall be included in .

determining the Inspection Results Category for that special inspection but need not be included in determining the Inspection _ Results Category for the general steam generator inspection. .

4.4.5.3 Inspection Frequencies - The above required inservice inspections of steam generator tubes shall be performed at the following frequencies:

a. The baseline inspection shall be performed to coincide with the first scheduled refueling outage but no later than April 30, 1980.

Subsequent inservice inspections shall be performed at intervals of 'not less than 12 nor more than 24 calendar months after the previous inspection. If the results of two consecutive inspect for a given"group

• of tubes following service under all volatil.

treatment (AVT) conditions fall into the C-1 category or if two consecutive inspections demonstrate that previously observed degradation has not continued and no additional degradation has occurred, the inspection interval for that group may be extended to a maximum of 40 months,

b. .If the results of the inservice inspection of a steam generator performed in accordance with Table 4.4-2 at 40 month intervals for a given group

• of tubes fall in Category C-3, subseque'nt inservice inspect _Jons shall be performed at intervals of not less than 10 nor more than 20 calendar months after the previous inspection.

The increase in inspection frequency shall apply until a subsequent inspection mee'ts the conditions specified in 4.4.5.3a and the interval can be extended to 40 months.

c. i.3ditional, unscheduled inservice inspections shall be performed on each steam generator in accordance with the first sample i inspection specified in Table 4.4-2 during the shutdown subsequent  :

to any of the following conditions:  !

1. Primary-to-sacondary tube leaks (not including leaks originating from tube-to tube sheet welds) in excess of the limits of Specification 3.4.6.2.

• A group of tubes means: .

(a) All tubes inspected pursuant to 4.4.5.2.b, or (b) All tubes in a steam generator less those inspected pursuant to 4.4.5.2.b. -

DAVIS-BESSE UNIT 1 3/4 4-8 Amendsent flo. 21

- , "*"^%L THIS PAGE PRDVIDED

., REACTOR COOLANT SYSTEM

~

- SURVEILLANCE REQUIREMENTS (Continued)

'?

' 2. A seismic occurrence greater than the Operat'ing Basis Earthquake.

3. A loss-of-coolant accident requiring actuation of .the

' engineered safeguards.

4. A main steam line or feedwater line break,

d. The provisions of Specificati.on 4.0.2 are not applicable.

4.4.5.4 Acceptance Criteria ,

a As used in this Specification:

1. Imperfection means an exception to the dimensioris, finish or contour of a tube from that required by fabrication drawings or specifications. Eddy-current testing.indicat. ions below 20% of the nominal tube wall thickness, if detectable, may be considered as imperfections.

2. Degradation means a service-induced cracking, wastage, wear or general corrosion occurring on either inside or outside of a tube. .

3. Degraded Tube means a tube containing imperfections > 20%

~

'of the nominal wall thickness caused by degradation.

4.  % Degradation means the percentage of the tube wall thickness- affected or removed by degradation.

5. Defect means an imperfection of such severity that it exceeds the plugging limit. A tube containing a defect is defective.

6. Plugging Limit means the imperfection depth at or beyond which the tube shall be removed from service because it may become unserviceable prior to the next inspection and is equal to 40% of the nominal tube wall thickness.

7. Unserviceable describes the condition of a tube if it leaks or contains a defect large enough to affect its structural integrity in the event of an Operating Basis Earthquake, a loss-of-coolant accident, or a steam line or feedwater line break as specified in 4.4.5.3.c, above.

8. Tube insoection means an inspection of the steam generator tube from the point of entry completely to the point of exit; DAVIS-BESSE, UNIT 1 3/4 4-9 _

Amendment No. 21

=-

r-WTH 87AEPROVIIEF

_ _ . . . .. ou y

. . r'3idI"jsdiidiUE

-,....a..

....... -=.2..

~

2 e n.e ...,..<.. e. ..,e...

,, . ,r....

. . .. . . e. ...,.ge.

. . .s . . 8. 8 .". -

• S *. - a *. .-

3.. . *. *. #. .- -. . c- .

,, , . .v a. . .-. .- .- . *. . - '. .- . a s .- . '. .' r .. s e ..v .i c .a . . e e . > .<. '. s . .

a :ase.. u--a.....:ne conci-icn c. .ne tubing. .

inis insoec ton shai' be ce #erme :-icr :: initial DOWER 00 ERAT:0N using i

ne e:uipmen; anc teen.icues exoected :: be usec trine.

su:secuen- inservica :nsce::icns.

.I

b. The steam generator snail be determined OPERA 5LE after com:le-ine the :Orrescending ac-# ens ::iv; all tubes ex:ee:ie; : e :1;:: .:

.i  :. . .

2.

....,, ....,<.e..

..... . . . . .. . .........,.,...:....e

... , r...,.,;-

{i Oy .:acie .- .. -

.I t,

j,,.

i

.:.: .ecerts li

a. Following eacn inservice ins:e:-icn of s: sam genera :r u:es, i

i the number cf tubes ciuggec in each s ea genera:or scali ce reacr:ed to the Com ission within 15 cays.

. The :: :lete re.sults cf the s eam genera Or ube inservice

.I ins:e:t..on sna . e su:m;; e,. en an annua. bas:. s in a re cr e

'or:neceriodinwhich-hisins:ec-ionwas'::m:leied. This i re:or: shall inciuce:

.l

. . . . . .x.... ..... . ..... .. ....,s 4

..s e.c... s..

.i

.i.

. 2. ' ::a-'.:n anc :er:en: ef wai

-hicxr.ess :ene ra-i:n #:r

..w. e. . C,. C ...c. . . n... : ,

....e.:,,.c.00.

.. = . . . . : : : .,., .. .i .. .7.

. .  : .=. ..e .. . .? ...

. .e.... ,. ..e,..,...

. . . . . . . . .. .... . . e.  :.e. . ,..:..e. ...... 4 a.....

a:eg:ry C-2 and receirt ;r::: nc-ifica-icn :f : .e  :., issie-f snali be re:Orted Oursuan to Spe:ifica:icn .i.; :rier ::

1 esum::icn of cian 0: era-ion. The sri- en #:: 1cwur of this recor scali Or0vice a des:r'::'en of inves-';a-i:ns ::nduc ec i

i. o determine cause Of -he tube ce;raca-icn an ::rre::ive 1

measures taker. :: :reven: re:urrence.

4.4.5.5 The steam generator shall be dem:ns ra ed GPER*2LE by verifying i

stea ;enerator levei :: :e witnin '.imits at leas: ence ;er 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, i 1

.. i

.. . l 4.4.5.7 Whan steam generator tube inspection is perforr.r.1 as per 1

Section a.4.5.2., an additional but totally separate insoection shall be performed on special interest peripheral tubes in the vicinity of the secured internal aexiliary feedwater header. This testing shall only be required on tne steam generator selected for inspection, and the test sha'l require inspection only between ,

g

"' " " ' " ' THIS PAGE PR0ilDE?

REACTOR' COOLANT SYSTEM SURVEILCANCE REQUIREMENTS"(Continued) the upper tube sheet and the 15th tube support plate. The tubes ,

selected for inspection shall represent the entire circumference '

of the steam generator and shall total at least 150 peripheral tubes. I 4.4.5.8 Visual inspections of the secured internal auxiliary feedwater header, header to shroud attachment welds, and the external header thermal sleeves shall be performed on each steam generator through the auxiliary feedwater injection penetrations. .

These inspections shall be performed during the third and fourth refueling outages and at the ten-year ISI.

I 1

DAVIS-BESSE, UNIT 1 3/4 4-10a knendment No. 62

--. w - - - .- , - _.

o m

e co m

m m

m TABLE 4.4-1 C

H MINIMUM NUMBER OF STEAM GENERATORS TO BE r M -

INSPECTED DURING INSERVICE INSPECTION r

No Yes -C.

Preservice inspection .

g @M: '

No. of Steam Generators per Unit Two Three Four Two Three Four 7 First inservice inspection All One Two Two S Second & Subsequent inservice inspections One l

One l One 2 One 3 Tabte Notation:

MW Qg

1. The inservice inspection may be limited to one steam generator on a rotating schedule encompassing 3 N % of the tubes (where N is the number of steam generat >rs in the plant) of the results of the first or previous inspections indicate that g-all steam generators are performing in a like manner. Note that under some circumstances. the oper. sting conditions so g one or more steam generators may be found to be more severe than those in other steam generators. Under such circum stances the sampts sequence shall be modified to inspect the most severe conditions. E T

2. The other steam generator not inspected during the first inservice inspection shall be inspected. The third and subsequent @%

inspections should follow the instructions described in I above. g

3. Each of the other two steam generators not inspected during the first inservice inspections shall be anspected durirw] the second and third inspections. The fourth and subsequent inspections shall fol:ow the instructions described in 1 above.

M g

3 CD C Clll3 2 O rvi kC w- ,- + e, - - - , e- + .r-- + , v- w - - , - , , - - , - -, - - ---

~ '

• 7;L THIS PAGE PROVIDED .

FORINFORMATION ONL i

i REACTOR COOLANT SYSTEM f

I BASES l

1 3/4.4.4 PRESSURIZER A steem bubble in the pressurizer ensures that the RCS is not a hydraulically solid system and is capable of accomodating pressure surges du-ing operation. The steam bubble also protects -the pressurizer i code safety valves and power operated relief valves against water relief. l The low level limit is based on providing enough water volume to prevent a reactor coolant system low pressure condition that would actuate the Reactor Protection System or the Safety Featura Actuation System. The high level limit is based'on providing enough steam volume to prevent a pressurizer hiah level as a result of any transient.

The power operated relief valves and steam bubble function to relieve RCS pressure during all design transients. Operation of the power operated relief valves minimizes the undesirable opening of the spring-loaded pressurizer code safety valves.

3/4.4.5 STEAM GENERATORS .

The Surveillance Requirements for inspection of the steam generator tubes ensure that the structural integrity of this portion of the RCS will be maintained. The program for inservice inspection of steam generator tubes is based on a modification of Regulatory Guide 1.83, Revision 1.

Inservice inspection of steam generator tubing is essential in order to maintain surveillance of the conditions of the tubes'in the event that there is evidence of mechanical damage or progressive degradation due to design, manufacturing errors, or inservice conditions that lead to corrosion. Inservice inspection of steam generator tubing also provides a means of characterizing the nature and cause of any tube degradation so that corrective measures can be taken.

The plant is expected to be operated in a manner such that the i secencary coolant will be maintained within those chemistry limits found i to result in negligible corrosion of the steam generator tubes. If the '

secondary coolant chemistry is not maintained within these chemistry limits, localized corrosion may likely result in r. tress corrosion cracking. i The extent of cracking during plant operation would be limited by the i limitation of steam generator tube leaka e between the primary coolant system and the secondary coolant system primary-to-secondaryleakage=1GPM). j Cracks having a primary-to-secondary leakage less than this limit during l operation will have an adequate margin of safety to withstand the loads DAVIS-BESSE, UNIT 1 B 3/4 4-2

_ _ __ _ _ _ _ _ _ . _-~_- _ _ ___.~ _. _ . _

6sent /WF a- IlilS PAGE PROVIDED REACTOR COOLANT SYSTEM _

BASES imposed during nonnal operation and by postulated accidents. Operating plants have demonstrated that primary-to-secondary leakage of 1 GPM can be detected by monitoring the secondary coolant. Leakage in excess of this limit will require plant shutdown and an unscheduled inspection, during which the leaking tubes will be located and plugged.

)

Wastage *-type defects are unlikely with proper chemistry treatment  ;

of the secondary coolant. However, even if a defect should develop in service, it will be found during scheduled inservice steam generator tube examinations. Plugging will be required for all tubes with imperfections exceeding the plugging limit of 40% of the tube nominal wall thickness.

Steam generator tube inspections of operating plants have demonstrated the capability to reliably detect degradation that has penetrated 20% of the original tube wall thickness.

Whenever the results of any steam generator tubirg inserv. ice inspec-tion fall into Category C-3, these results will be promptly reported to the Comission pursuant to Specification 6.9.1 prior to resumption of plant operation. Such cases will be considered by the Comission on a case-by-case basis and may result in a requirement for analysis, labora- f tory examinations, tasts, additional eddy-current inspection, and re- .

vision of the Technical Specifications, if necessary. I The steam generator water level limits are consistent with the initial assumptions in the FSAR.

DAVIS-BESSE, UNIT 1 B 3/4 4-3 l

l -