ML20065S806

From kanterella
Revision as of 16:47, 31 May 2023 by StriderTol (talk | contribs) (StriderTol Bot change)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

Advises That Diverse Scram Sys Logic Circuit Simplified.New Design Reduces Number of Procedural Steps Required by Operator to Reset Protective Actuation
ML20065S806
Person / Time
Site: Three Mile Island Constellation icon.png
Issue date: 12/19/1990
From: Hukill H
GENERAL PUBLIC UTILITIES CORP.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
C311-90-2146, TAC-59151, NUDOCS 9012260075
Download: ML20065S806 (4)


Text

--_- . _ _ _ _

GPU Nuclear Corporation u Nuclear  :=s:r8o Middletown, Pennsylvania 17057 0191 717 944 76?1 TELEX 84 2380 Writer's Direct Dial Number:

December 19, 1990 C311-90-2146 (TAC 59151)

U.S. Nuclear Regulatory Cctstission Attn Document Control Desk Washi.rgton, D.C. 20555 Gentlemon:

Subject:

Throo Mile Islard Nuclear Plant, Unit 1 (IMI-1)

Orcrating Licenso DPR-50 Docket No. 50-289 A1WS Design Implementation Simplification of Protectivo Action In the GPU Nuclear (GPUN) Ictter (C311-89-2058) dated October 4, 1989 GPUN described the Diverra Scram System (DSS) design relativo to completion of Protective Action at pago 11 and depicted on Figure 1. (Figure 1 is enclosed for caso of referenoo)

GPUN has ncw simplified the DSS logic circuit as depicted on Figure 1A also enclosed with this letter. Inck-up/ Scal-in of the DSS trip function is ncu achieved by the action of circuit breakers 1G-2A ard 11r2A, which lock-in/soal-in inherently, by design. Roset is dono locally by the operator at the breakers.

This simplified design achieves a reduction in the numter of procedural steps rcquired by an operator to reset a protective actuation. In the original design of Figure 1 the three stop proceduro consisted of: (1) Roset tho actuation; (2) recloco the breaker to energize the control Rod Drive System (CRDS); ard, (3) withdraw control rcds usirq the CRDS. The revised design is more typical of GWN procedures to reset a protectivo action. The two step procedure is: (1) reclose the breaker; and, (2) withdraw control rods using the CRDS. The acklitional step built in to the original design is unremry and results in added circuit acruplexity.

9012260075 901219 ,? p PliR ADOCK 0500028 p PDR ig GPU Nuclear Corporabon as a subsidia y of General Public Utili ties Corporation g 4 .s p ,., ,/,,

A9;J0 .

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

. C381-90-2146 e 1

This revir.cd design inplementation for Cttpletion of Protectivo Action has bocn dico meM with the Staff. The puTose of this letter is to doctment the subject design ctwyo, sinocroly, c

!)! D. I bl1 Vloe President ard Director IMI-1 I

IDi/Gi3/ pip l

oct Administrator, Region I Director, Project Directorate I-4 imC 1MI-1 !!RC Project Marnger Senior imC Resident Inspector l

0 I

D k em$h s$h m

3

. : a a

7~ _O O "

C

? "

e -

E o -

~

g gu e

b .- d - Es3 g ca l

e v

d a:( w g u S;e w w .o ,

c (f)h '

) $

l, mc C "

v

z a

-e we b 2 (W 50 e e M2 4 d We

  • 0 8

,o 2 Ev.h. oh.

-o.

9 f sw 5"

gsg m a gh .. d sy w ,. . . ;.

t . . . .,.

@ e<k g

9Cll i

++S doa;.

mg Eo n Ee '

wiu 88g 5

Z D

14. D

I

. s.

t g

. - sw@

a s a '

g .. g 5 -

g 41 td.

G

-L $

m -

  • y ,& '

L_ v  ;

~

$ h a N - $ l 5 {.

ha M k -

e. ,.

Wh mc a S 2

i 3

s f

Q "

g v= f.

d Eff

$ l$

eft a= eu .: 1, xe 3 e2 s.

Iss kH E 3 . .

E

. H k. e sose m.. <d k -

< ,--J t . . . .; N g fime :

$$b!

us!l ggi  :

uw ..

I':

D

.n. 3

- _