ML20082D790

Proposed Emergency Tech Spec Change Re Reactor Feedwater Inboard Check Valve Type C Test

ML20082D790
Person / Time
Site:	LaSalle
Issue date:	11/21/1983
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML20082D788	List: ML20082D785 ML20082D790
References
NUDOCS 8311230053
Download: ML20082D790 (6)

Text

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ATTACHMENT A' I

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-LASALLE COUNTY STATION UNIT-l

. TECHNICAL SPECIFICATION CHANGE REQUEST i

SUBJECT:

Reactor Feedwater Inboard Check Valves Type C Test REFERENCES-(a): FSAR' Figure 6.2-32 (b): Technical Specificction Page 3/4 6-32 BACKGROUND' LaSalle County Station has a reactor feedwater system primary containment

.shown oniFSAR valve Figure arrangement 6.2-32 Detail with (b) three (3) valves per feedwater line as '

(2) check valves and a motor operated gate valve.(see attached). Each line has two

.the intent of General Design Criterion 55 -on "the other defined basisThis arra criteria".

J' design able'preserves to maintain reactor coolant. makeup from allThis the reliable coolant makeup to the react .

source or vessel from theLnormal feedwater lines. source when required and prevents inadvertent isolation of the When the plant was originally designed, Commonwec1th Edison. believed that.only two isolation valves were required on these lines per priordominating requirements NRC. interpretations of GOC 55 regarding feedwater make-u the isolation requirement.

the motor operated 1821-F065A and B lfeedwater-injection val specic 2 o p e r a t e d a c t u'a't o r s . .. positive-closing check' valves 1821-F032A and B which have.

supplied' vith oower, from a separ~ ate ESS power bus, and can b from the control room following a loss of offsite electrical power

-Each of the outboard, positive-closing check valves has testability .

-features" to conform Jto 10 CFR 50, Appendix J criteria. The feedwater line between the inboard >and-outboard feedwater check valves as the~ valves themselves were specially designed and constructed in accord-

.cnce preclude with'the. Standard Review Plan 3.6.2-10, and ASME Section 3, so as to check valves (the

-  : possibility "superpipe" of a credible feedwater line break between the criteria).

The inboard feedwater check criteria andLwere procured with a dif ferent . leakage

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They were toleranc Dinstalled only to' prevent a significant loss of inv entory in the event of a-feedwater line break. Subsequently, prior to the issuance of the Unit 1 to be; tested to 10 CFR 50, Appendix J criteria, as containm valves, in. addition to-the.other two valves in these lines. A low

prossure seal feature was therefore added to these inboard feedwater ichsckuvalves'to meet the. Type C test requirement as designated in the Tech Spocs. 8311230053 831121 PDR p ADOCK 05000373 3 PDR

DISCUSSION

- On November 3, 1983 LaSalle County Station Unit l'was shutdown for a-brief cold shutdown outage to perform various maintenance and

surveillance items. While testing the reactor feedwater lines per Technical Specification surveillance requirements 4.6.1.2.d, it was

' determined that the reactor ~feedwater inboard check valves 1821-F010A and B did not meet Technical Specification 3.6.1.2.b.for primary containment combined leakage rate limit :for Type B 'and C tests (0.6 La).

Commonwealth Edison currently anticipates replacing the seal material for the inboard feedwater check valves in accordance with the design.and material specified by the valve manufacturer.

Following the -first failure of the valves to pass a local leak rate' test which1was performed after approximately eighteen months of operation, we observed.some damage to the original seal material, which we concluded-was_the result.of machining the material rather than grinding it to tolerance. We also. concluded that the sharp edges around the pressure equalizing ports in the disk had cut the seal material in multiple locations. These' sharp edges have since been removed.

- Because of_ the difficulty of obtaining molded seal material as cas used for the originaliseals, the_ manufacturer supplied new seals which were extruded and the: ends of the material were vulcanized together to form:the seal. On. November 3, 1983,.following approximately another

' month of operction,"the inboard feedwater check valves again failed to pass local leak rate tests. . The inspection of the seals revealed a gap

.in'each seal on the circumference, one about one-half inch long and the other about one and one-half inches in length, at the vulcanized points of the seals. The seal material in the "B" valve also appeared to be brittle with multiple. minute cracks. We are also investigating a possible alignment problem that may have prevented the disk from closing squarely against the seat which could also contribute to type "C" test failure.

.The valve manufacturer.is now supplying Commonwealth Edison with

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new molded seals as in the original design. We believe this will resolve the new and different failure modes which were experienced with the Gxtruded/ vulcanized seals. A representative of the manufacturer is

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also

, Lon-site to evaluate the ef fects of- the alignment' tolerances.

- _ . With these repairs,.we believe that the seal design and material

, in the; inboard feedwater check valves will be essentially identical to the seals which have been successfully used and tested at other sites for

_ periods of several years. We also anticipate that a successful local leak rate ' test will be passed following the repairs currently in progress on the inboard'feedwater-check valves.

9 -m m,i-ep.-.--y-y +-+w- *g *-m,-w.g- si - - ygvsr mys-ww-qw-- -

1 pass the. local leak rate test criteria following valvesoperatio to further relief from the Appendix J criteria should be s . ns, we feel that valves until solutions to the existing problems can ought be for these res l further repairs

' refueling outage. and/or modifications can be performed o d ved and uring the first CONCLUSION in each line which meet the requirements aof onAppendix because the outboard motor' operated isolation valv CFR 50, valves power from an ESS bus, and because the feedwater line betwe e is supplied with check valves is designed and constructed so as entothepreclude two ac line break, it is believed that no unreviewed safety ha that compliance with GDC 55 is not compromised e

therefore, Commonwealth Edison pre .

zard exists and Technical Specifications to Lices ,ses to change the Appendix AFor LaSalle Un This amendment will exempt the Feedwater ueling outage. Line Inbo Appendix outage. 3 Type C testing until startup following th eck Valves from currently valves in cachvalid Type feedwater line: C tests performed withir, e n

y s on two the past Outboard Remote Manual Isolation6-27)

Tcch Spec Page 3/4 6-32),

Valve (Item #2(Ite and Feedwater 1821-F065A and B on

1. 2,.1G33-F040, on Tech Spec Page 3/4 6-32)and Reactor' Water Clea,nup Retu stratively controlled as stated in the LaSalle "The valvc(s) is remote manually closed from the FSAR Se will be admini-on 6.2.4.2.1:.

provide long term leakage protection upon operator deter imain' control continued (a f ter LOCA) makeup

." from the feedwater system ismunavailable nation that necessary or un 7215N t

AMENDMENT 47

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OCTOBER 1979

() RPV Containment

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A0 A0 L=J L=3 . .- ?

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, C)<] O [><J l M0 TC M0 -

_ MO O I G 33 - s:o yo

[> <3 1 TC TC A0 M0 D

% " 1821-Fo104[3 f

i vp i

[)< }

I 821-FoilA I 821-5:03;W I B2.1-A066A -

TC V EED u 4)TEw L., esa A a s s ua.a n, ; t.1n>a s ,s sim>>.ne Reec.rve W4MCurwnwe W .vu IG 3 3.F040 s s c.nm mmj T'o 8 oru A no B uduu e-s J

$0 or or i M0 TC M0 B C l DETAll. pq []

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[>d }

l (c)

NOTE: TC DESIGNATES TEST CONNECTION. LA SALLE COUNTY STATION

- FIN AL S AFETY AN ALYSIS REPORT FIGURE 6.2-32

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CONTAINMENT VALVE ARRANGEMENTS (SHEET 1 of 10) 1 -

t I- m . .R d' ',i

- - a TABLE 3.6.3-1 (Continued) 5 s. '. i .c ,

y, PRIMARY CONTAINMENT ISOLATION VALVES y 9' . . ' .i .

g VALVE FUNCTION AND NUMBER

h d. Other Is'olation Valves

. i' . e H 1. MSIV Leakage Control System

- t i. .

g) 1E32-F001A, E, J, N ,

2.  ; Reactor Feedwater'and RWCU System Return 1821-F010A, B N 1821-F065A, B > ;.. p. ' " ,

~1G33-F040

~1 n i1.sti. n' i 1,

. R 3. Residual' Heat Removal / Low Pressure Coolant Infection System .

I 1E12-F042A,' B, C g' 4 '1E12-F016A, B N 11E12-F017A, B-

,IE12-F004A,. Bgg )

U 5

c. 1E12-F027A,' B U) i1E12-F024g))B IE12-F021 1

'1E12-F302U)~

j  ;1E12-F064A,.B U) i 1E12-F011A,

'1E12-F088A,[ Bgg 8,' C IE12-F025pj)B,C IE12-F030 '

1E12-F005U ) ',

y

.1E12-F073A,:8 d F .IE12-F074A;.B , y, , unw) -

' IE12-F055A, cB g) ;.,., , ,c, +

j i., /MAi IE12-F036A, .BU) 3 i

.~ E 1E12-F311A, B U)-

?J 1E12-F041A,B(kh - - - - -

'. dint

- - /c CthtiVInau

,; 1E12-F050A, B '

.4 , n M A/or $8JECr. ,oTvs dE)9ME Tasi' 0M7: L Shs o FoN'%

l P ruc e,4s, so-u owacc  ; l i

ATTACHMENT B Significant Hazards Consideration Commonwealth Edison has evaluated the proposed Technical Specification Amendment and determined that it does not represent a significant hazards consideration. Based on the criteria for defining a significant hazards consideration established in 10 CFR 50.92, operation of LaSalle County Station Unit 1 in accordance with the proposed amendment will not:

' 1)- Involve a significant increase in the probability or consequences of an accident previously evaluated because of two (2) other valves in the line will be type C tested per the Technical Specifications, FSAR and Appendix J to 10 CFR 50 criteria and Commonwealth Edison believes this change is an acceptable alternative to General Design Criteria 55.

2)- Create the possibility ~of a new or different kind of accident from any accident previously evaluated because:

a) The containment leakage criteria will still be met even with single failure since two valves in the line will meet Appendix J criteria.

b) The feedwater line break accident will not be affected by this change because the inboard check valve will still be able to prevent gross inventory loss if a feedwater line break were to occur.

3) Involve a significant reduction in the margin of safety because the leakage criteria for the primary containment as a whole will still moet the leakage margins as required by Appendix 3 to 10 CFR 50.

Commonwealth Edison believes that two valves in each line which meet Appendix J criteria is an acceptable alternative to General Design Criteria 55 on the "other defined basis criteria."

Based on the preceding discussion, it is concluded that the proposed change clearly falls within all acceptable criteria with respect to the system or component, the consequences of previously evaluated accidents will.not be increased and the margin of safety will not be decreased. Therefore, based 'on the guidance provided in the Federal Register and the criteria established in 10 CFR 50.92(c), the proposed change'does not constitute a significant hazards consideration.

.7215N

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