ML20207B253

Proposed Tech Specs,Revising Table 3.6-1 to Add Potential Leakage Paths W/Unit 1 Hydrogen Analyzer

ML20207B253
Person / Time
Site:	Sequoyah
Issue date:	07/25/1988
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20207B230	List: ML20207B224 ML20207B253
References
NUDOCS 8808020283
Download: ML20207B253 (12)

Text

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ -

. s . .

ENCLOSURE 1 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PLANT UNIT 1 DOCKET NO. 50-327 -

(TVA-SQN-TS-88-09)

L2ST OF AFFECTED PAGES Unit 1 3/4 6-6 i

l' l

8808020283 GG0725 PDR ADOCK 0S000327 P PDC

. -_..-. ......t

.+

' TABLE 3.6-1 (Continued)

M BYPASS LEAKAGE PATHS TO THE AUX 1LIARY BUILDING E -

SECO*;DARY CONTAlhMENT BYPASS LEAKAGE PATHS '

O 5

. PfMETRATION DESCRIPTION RELEASE LOCATION c

3 X-64 A/C Chilled Water (ERCW) A ufliary Area X-65 A/C Chilled Water (ERCW) Auxiliary Area X-66 A/C Chilled Water (ERCW) Auxiliary Area X-67 A/C Chilled Water (ERCW) Auxiliary Area X-68 ERCW Auxiliary Area X-69 ERCW Auxiliary Area X-70 ERCW Auxiliary Area X-71 ERCW Auxiliary Area X-72 ERCW Auxiliary Area X'73 ERCW Auxiliary Area X-74 ERCW Auxiliary Area w X-75 ERCW Auxiliary Area ,i 75]

, 1 X-76 Service Air Auxiliary Area l m X-77 Demineralized Water Auxiliary Area 1- J, X-78 Fire Protection Auxiliary Area li X-81 RC Orain Tank Auxiliary Area ,

Fuel Pool '

X-82 Auxiliary Area X-83 Fuel Fool Auxiliary Area

.' X-84A Pressurizer Relief Tank Gas Sample Auxiliary Area X-8SA Excess Letdown Heat Exchanger Auxiliary Area

^

c X-90 Control Air Auxiliary Area mX-91 Postaccident Sampling, Hot Leg 1 Auxiliary Area M 'X-93 Accumulator Sample Ai.xiliary Area

.l ; , X-94ABC Radiation Sample Auxiliary Area X-95ABC Radiation Sample Auxiliary Area

)4 1F X-%C Hnt Leg Sample Auxiliary Area g-98 ILRT Auxiliary Area j . X-101 Postaccident Sampling, Containment Auxiliary Area i Uy ! X-103 Postaccident Sampling, Liquid Discharge Auxiliary Area

.y A to Containment 1  ?..! X-106 Postaccident Sampling, Air Discharge Auxiliary Area A to Containment L

X-108 UHI Auxiliary Area 0

Q lX-% H y jpu,;Iar. Ara

.( T

_x- oo og/c3a,A,,ayzer a,, Aal r er- p:1.k Rre- ,

j~x -92. A,8 H_, dim ,,s%=lyzer Aa,x.%q , Area.

ENCLOSURE 2 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PLANT UNIT 1 DOCKET No. 50-327 _

(TVA-SQN-TS-88-09)

DESCRIPTION AND JUSTIFICATION FOR TdE REVISION OF TABLE 3.6-1, "3YPASS LEAKAGE PATHS 10 THE AUXILIARY BUILDING"

)

e

ENCLOSURE 2

.:_ l Description of Change Tennessee Valley Authority (TVA) proposes to modify the Sequoyah Nuclear Plant (SQN) unit 1 technical specifications to revise Table 3.6-1, "Bypass Lentage Paths to the Auxiliary Building," to add four potential bypass imkege paths associated with the hydrogen analyser system. --

Reason for Change During the review of a design change notion (DCN) issued to enhance the ,

hydrogen analyzer calibration process, it was discovered that the current system design contained a potential pathway for the relear.e of radionuclides to the environment following ; postulated loss of coolant .

accident (LOCA). Previously, the hydrogen aftalyser system was considered a closed system with respect to containment icolation. ,

This proposed technical specification chsnge is needed for unit 1 to identify the bypass leakage paths to the Auxiliary Building. Inclusion of  :

these potential leakage paths in table 3.6-1 of the unit 1 technical specifications ensures that these bypass leakage paths are tested in accordance with 10 CFR 50, Appendix J and specification 5.6.1.2. This change is similar to a previously approved technical specification change (87-46) for unit 2 that was suamitted to NRC on March 1, 1988.

Modifications to the unit I hydrogen analyzer system are being performed i I to eliminate the potential bypass leakage to the environment. In ordec to i comply with specification 3.6.4.1 for operable hydrogen analyzers, the unit 1 modifications will be completed before entering mode 2. These modifications are Ming performed under DCNs M00229, M00230, M00231, and M00232 as part of ;,e corrective action to Conditiont Adverse to Quality Report (CAQR) SQP871652 R1. This CAqR encompasses the design inadequacies that were documented for unit 2 under SQP871611 and SQP871650. These deficiencies were also reported to NRC in Licensee Event Report (LER) '

327/87077, t Justificatinn for ",*4ng

! FIAures 1 and 2 show the unit 1, train A and B, hydrogen analyzer system configurations that contained the potential bypass 1takage path to the environment. After the postulated LOCA, the in5oard containment isolation ,

valves (CIVs) would have been open because they vere fail-open, I air-operated valvesI and the control air would have been isolated during ,

the accident. If the hydrogen analyzer was in the "analyse" moda, the electrically operated solenoid valve on the reagent-gas line would have been open as designed. If the failure of one train of essential control air was also postulated, the pressure in the control air line (reagent gas) supp ving tne hydrogen analyzer would have fallen below containment pressure allowing the potential bypass leakage to the environment through the essential control air system.

se %e'm M 6 4 a b. _-M, y

Figure 3 shows the modified hydrogen analyzer system configuration for trains A and B. DCN M00229A (phase 1) will be completed before mode 4 to establish containment integrity while in modes 4 and 3. This DCN replaces the unit 1, train A and B, inboard CIVs with electrically operated fail-closed solenoid valves and adds new electrically operated fail-closed outboard CIVs inside the annulus. The new outboard valves will be electrically connected during implementation of DCN M00230A (phase 2).

These valves are TVA class B qualified to be operated in a harsh environment for 30 days and leak tested in accordance with existing procedures. DCN M00231A (phase 3) modifies the portion of the hydrogen analyzer system located in the Auxiliary Building to eliminate potential bypass leakage paths to the environment. The analyzer will be disconnected from the essential control e.ir system for bnth trains.

Bottled air will be used as the reagent-gas supply. DCN M00232A (phase 4) electrically connects the calibration panel snd associated instrwoentation.

The configuration proposed for the unit 1 hydrogen analyzer system will eliminate the need for the administrative concrois that are currently used for unit 2. Unlike the unit 2 design, the unit I hydrogen analyzer system will not be required to maintain a pressurized calibration / reagent-gas system. This is due to the fact that the unit 1 calibration panel and associated gas supply bottles are located entirely within the Auxiliary Building Secondary Containment Enclosure (ABSCE). In addition, the unit 1 outboard containment isolation valves are located on the hydroget. sample line inside the annulus rather than on the reagent / calibration lines inside the ABSCE. The administrative controls for maintaining a pressurized calibration / reagent-gas system are thereby eliminated.

The reagent-gas pressure switch will be configured for both trains to provide an automatic trip of the hydrogen analyzer sample pump and automatic closure of the inboard / outboard CIVs on a low-pressure signal.

The new inboard / outboard containment isolation valves will provide a double containment isolation barrier for protection against potential leakage out of containment. Any leakage from containment would be required to follow a tortuous path through two containment isolation solenoid valves and into the hydrogen analyzer reagent-gas or calibration-gas lines before reaching the ABSCE. Because the entire calibration panel is located inside the ABSCE, any leakage would be processed by the Auxiliary Building Gas Treatment System (ABGTS).

The orfsite dose analysis of record (Final Safety Analysis Report, st.ction 15.5.3) is not affected by moving the potential release point of the hydrogen analyzer system from the annulus to the ABSCE. This is because the total primary containment leakage remains unchanged, as do the assumptions that 75 percent of the leakage is to the annulus and 25 percent of the leakage is to the Auxiliary Building within the ABSCE.

The change in potential release points only changes the allowable leakage for each individual penetration.

l l

i L -

l l

i

• r In sununation, the modifications described above will ensure that the system meets containment isolation requirements. These modifications will also eliminate potential bypass leakage paths to the environment, ensuring compliance with containment bypass leakage requirements. Potential leakage paths to the ABSCE will still exist and are included in the technical specifications. Inclusion of these potential leakage paths in --

the table ensures that they are adequately tested in accordance with i

10 CFR 50, Appendix J, and specification 3.6.1.2.

1 i

l l

l

-w,>,w_,- we,--- me w-w yy- --ywyeyy--wyy wwp,a

7-5 W-o9 ,

. FMcAE .L

~

l!YDROGEli ANALYZER 'SYSTEf/ SClEFINCC (EXISTillG CONFlGURATION FOR TRAlls A) t rei [.ow l11 essure siipinl CJY y '

lo rinntrnciqlui in flCft O g L FCV- 43-2 2 T *: h F V 'l

• 00ACl~rh) PS 'I - 00A (Tr A)

'S (15 vsis selvolust)

Ec4 gens g1s

[

1. ~'

M l- /

J' 4-E5 5thfiell ~ '

l pg.g3-llh I.; eontrolesi-t r

l* ~ ~

Calil; ofien ,ggs / I.'eplafor (Id IcutI Eilft CI)f v Sf' "

l 4 g/ filter s'irnpl e insiile ry;cql of 4 J,og. I,ox )

A _,\llYllROGEll e

-wy f  ! -

"~'

y. AllAl.YZT.It FCV-<!3-201 (Tr A) h'[*;'[S",',Ijog j

1 ABSCE+

INBOARD e < 4NNUIUS 4 +-AUX HLI)G. 5 3--'a,.,,, not ,

co L gas I.or sles -

l -,

typical of.4 t

f p .

L.. -

~

/ 5 SF-09 .

neons 2 -

HYDROGDI ANALYZER S'(STEM SCllEl4K~lC (EXISTillG C0i'IFlGURATION FOR TRAIN B)

~

e., '

~

[.tu il es5ure sigrial '

ClY y , Io 48 "f'88ciqlot . : ilCit O A .

i

- M "8 TSV- 13-2104 (.lt U) I'5- 13-2l0A (li- 13)

I CY--!3-2Uli(l*r U) is5 (IS lssl3 s e tgoo itst )

1. J rc 2 Rea3ent sas [/ g, ,,,;,, g ,

r ceierf rol eter-rc i 14--

Cnlararron ses 7'" >-l4 R

g/yvisor r.frer (fi ence 3.isli sningle nisi<le ClV y --- spical of 4 Iiot bor-)

A Ill'l>ROGEll

_q q -_ __

x-gu y

p)ilAI.v7.r.it o" s s'eix 0'",sj* "0 s

1 FCV 13-201Cli- U]

ABSCII- ~

i lilBOAP.D  : < AilllVLUS  ? t- AllX, llLilG $' i ~

Calil.intions I, l eJ ts IrelIIG5 -

tyical of 4 3

(r .

n. . , . O e * ,

g h 0

a I ,e

, .g."

-. ~ ~.

6

, e g 3 eV '

I ,

. .@ g g n -

.ll . . . . . . .

t i 1" g  ; y r r n7 k a s% i . .

< a O O b >

kdj) _ i{a:ekf I-  !

p 0-E 01 EH:D$h[l y e,-

g s.

b: 3 c 3.,, ,.

ce .,i -

-l .

A[

i>

w = E. ,

@ )

3 i

% 4 2 W Q E S X J

R '

+ *

)

.I 2 -fy-,

Mr 04 ttr Q ?e o++-- 4 f'

EME E$,

I _

El-XI$ >

H '35 a-H  ! '

EH,Q ef EH: Iy a[3'I

. t s ?E g' n

S

• - - _ en= %, w e O

ENCLOSURE 3 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCIEAR PIANT JNIT 1 DOCKET NO. 50-327 -

(TVA-SQN-TS-88-09)

DETERMINATION OF NO SIGNIF1 CANT HAZARDS CONSIDERATIONS 1

- .. d

~

ENCLOSURE 3 Significant Ha:ards Evaluation TVA has evaluated the proposed technical specification change and has determined that it does not represent a signifier.nt hazards consideration .-

based on criteria established in 10 CFR 50.92(c). Operation of SQN in accordance with the proposed amendment will nots (1) Involve a significant increase in the probability or concequences of an accident previously evaluated. The addition of the hydrogen analyzer system bypass penetrations to table 3.6-1 ensures that the penetrations are properly tested in accordance with surveillance requirement 4.6.1.2.e. This testing does not affect the probability or consequences of previously evaluated accidents. The hydrogen analyzer system is not required to mitigate design basis events but is used to provide post-LOCA information to the operator in compliance with NUREG-0737. The hydrogen analyzer system does not contribute to the probability of leakage paths from containment to the environment. The remaining potential bypass leakage paths are into the ABSCE and are included in table 3.6-1 as such. Eliminating the leakage paths to the environment will decrease the consequences of an accident. The offsite dose analysis of record (Final Safety Analysis Report, section 15.5.3) is not affected by moving the potential release point of the hydrogen analyzer system from the annulus to the ABSCE. This is because the total primary containment leakage remains unchanged, as de the assumptions that 75 percent of the leakage is to the annulus and 25 percent of the leakage is to the Auxiliary Building. The change in potential release points only changes the allowable leakage for each individual penetration. The change coes not impact systems or components used to mitigate postulated accidents. The probability or consequences of previously evaluated accidents has not been altered.

(2) Create the possibility ot . new or different kind of accident from any previously analyzed. *he inclusion of the hydrogen analyzer system bypass penetrations in table 3.6-1 identifies the penetrations as being within the scope of surveillance requirement 4.6.1.2.e. The leak rate testing required by this surveillance does not create the possibility of a new type of accident. The changes made to the hydrogen analyzer system do not affect the function or operation of the system. The changes are made to eliminate potential leakage paths from containment to the environment. The change does not adversely affect other systems; therefore, no new accident scenarios are created.

(3) Involve a significant reduction in a margin of safety. The proposed change ensures that the hydrogen analyzer system bypass penetrations are routinely tested under the requirements of surveillance requirement 4.6.1.2.e. This testing ensures that the plant is

_g, l l

4 bounded by the offsite dose analysis of record. As described above. '

the offsite dose analysis of record is,not affected by the proposed i changet and the margin of safety as defined by the technical '

specification bases is not changed. The modifications to the

,. hydrogen analyser system eliminate a potential bypass leakage path to the environment and bring the system into compliance with containment '

.; isolation requirements. Any leakage will be into the ABSCE where it  !

is processed by ABGTS. The technical specification change is made to

~

reflect the potential bypass leakage paths to the Auxiliary Building. Because the poter.tial for unprocessed bypass leakage is ,

eliminated, the actual margin of safety is increased. j i

r

i l h

! i l  :

L i

i

$ I t

)

t i

I f

l I

t I

,_ - = = . - _ . =r n= ~ 2E =--L'\