ML19325D702

Forwards Relief Requests 44 & 49 for Plant Reactor Head Vent Valves.Util Requests That Valves Be Exercised for Operability Only During Cold Shutdown to Preclude Possibility of Overpressurization of Downstream Piping

ML19325D702
Person / Time
Site:	South Texas
Issue date:	10/19/1989
From:	Mcburnett M HOUSTON LIGHTING & POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
ST-HL-AE-3245, NUDOCS 8910250349
Download: ML19325D702 (4)

Text

- --

s' 4 '

p, x .a Hs The Light

! P.O. Box 1700 llouston, 'Icxas 77001 (713) 228 9211

[. Houston Lighting Ac Power,-

llL L'

[i October 19, 1989 C ST-HL-AE 3245 n File No.: C9.16 f 10CFR50.73 0

U, S. Nuclear Regulatory Commission l' Attention: Document Control Desk Washington, DC 20555 South Texas Project Electric Generating Station Units 1 and 2 Relief Requests I;R 44 and RR-49 for Reactor Head Vent Valves Attsched are relief requests RR 44 and RR-49 for the STP Unit 1 and Unit 2 reactor head vent valves, respectively. HL&P is requesting these valves be exercised for operability only during cold shutdown to preclude the possibility of overpressurization of downstream piping.

HL&P will revise the IST Program upon NRC approval of the relief requests.

If you should have any questions, please contact Mr. A. W. Harrison at (512) 972-7298.

I . , k-L .

/77e

. McBurnett mg l ,

Manager H Support Licensing l

i i

MAM/SDP/n1 Attachments: 1. RR-44 for Unit 1 Reactor Vessel  !

l Vent Valves FV 3657 A & B h FV-3658 A & B, HCV-0601, HCV-0602 1'

l

2. RR-49 for Unit 2. Reactor Vessel  ;

Vent Valves FV-3657 A & B, i FV-3658 A & B, HCV-0601, HCV-0602 8910250349 891019 PDR ADOCK 05000498 P PDC A1/035.NL8- A Subsidiary of I-louston Industries incorporated A0'f7

' \

1. . u

y. ,o 4.. . .

l \

3

s i.,

3 llouston Lighting & Power Cornpany

, ST HL AE-3245 File No.: C9.16

- Page 2 q cc:.

' Regional Adm'inistrator, Region IV Rufus S. Scott Nuclear Regulatory Commission Associate General Counsel f 611 Ryan Plaza Drive, Suite 1000 Houston Lighting & Power Company Arlington, TX 76011 P. O. Box 1700 Houston, TX 77001 George Dick, Project Manager U. S. Nuc1 car Regulatory Commission INPO

, Washington, DC 20555 Records Center 1100 circle 75 Parkway

~ Jack E. Bess .

Atlanta, CA 30339 3064

~

3 Senior Resident l Inspector - Unit 1 c/o U. S. Nuclear Regulatory Commission Dr. Joseph M. Hendrie P. O. Box 910 50 Be11 port Lane Bay City, TX 77414 Be11 port, NY 11713 J. I. Tapia D. R. Lacker Senior Resident Inspector - Unit 2 Bureau of Radiation Contrcl c/o U.'S. Nuclear' Regulatory Commission Texas Department of Health P. O. Box 910. 1100 West 89th Street  :

Bay City, TX 77414 Austin, TX 78756 3189 i J. R. Newman, Esquire Newman & Holt:inger, P. C.

1615 L Street, N. W. i Washington, DC 20036  !

R. L. Range /R. P. Verret Central Power & Light Company ,

P. O. Box.2121 l y Corpus Christi, TX. 78403  !

.R. John Miner (2 Copies) l Chief Operating Officer City of Austin Electric Utility j L4 721 Barton Springs Road ,l L Austin, TX 78704 l R. J . Costello/M. ' T. Hardt l la ' City Public Servico Board l P. 0. Box 1771'  :

L San Antonio, TX 78296 l

Revised 06/16/89 A1/NL.DISR4

e , ,-

V>; i * ;p Y' '

v ,.

lb 1-

[. , lhdistori 1.ightitig & power Comparty'  ;

RR-44 t

TEST REQUIREMENT l

[ >

Exercise valves for operability at least once every three (3) months. '

[

f.

,. BASIS'FOR RELIEF I. '

The head vent valves (hydraulic assisted, pilot operated) and head 1

- vent block valves are normally closed during plant operation. These valves, '

when exercised, exhibit a phenomenon called " burping". Burping is defined as a closed valve suddenly opening and reclosing without a signal or electric ,

power input. The burping occurs when the inboard valve is stroked open then l,

b the downstream valves give indications;in the control room of opening. This- .

burping'can occur for a period of up to 40 seconds thereby over pressurizing '

the downstream piping. The over pressurization would create unwanted pipe  !

!. stresses resulting in damaged piping.

. ALTERNATE TESTING

[ These' valves will be required to be exercised (full stroke) each cold

[c.

shutdown not to exceed once every three months.

1 5

I s

, ' A1/035.NL8 i

.g i '

m....

p , . .. .

f.

F  !

h. ..4

..?'

h - M*>uston Lighting & Power Company t-f 1

RR-49 TEST REOUIREMENT Exercise valves for operability at least once every three (3) months.

BASIS FOR RELIEF.

.l The head veut valves (hydraulic assisted, pilot-operated) and head vent l block valves are'normally closed during plant operation. These valves, when exercised, exhibit a phenomenon called " burping". Burping is defined as a closed valve suddenly opening and reclosing without a signal or electric power input. The burping occurs when the inboard valve is stroked open then the downstream valves give indications in the control room of opening. This burping can occur for a period of up to 40 seconds thereby over pressurizing the. downstream piping. The over pressurization would create unwanted pipe stresses resulting in damaged piping.

ALTERNATE TESTING

.These valves.will be required to be exercised (full stroke) each cold shutdown.

not~to exceed once every three months.

1 i

i i

i I

f f

i i

n ,

i 1 1 1

'A1/035.NL8

g. I