ML20087A260
| ML20087A260 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 07/28/1995 |
| From: | SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| Shared Package | |
| ML20087A247 | List: |
| References | |
| NUDOCS 9508040250 | |
| Download: ML20087A260 (7) | |
Text
_ _ _ _
2 l
1ABlE 4.3-2 (Continued) l; m
ENGINEERLD SAf[lY FEATURE ACTUAll0N SYSTEM INSTRUNENTATION E
SURVEILLANCE REQUTATMENTS i
B
.E IRIP
[
ANALOG ACTUATING i
M00ES FOR CHANNEL DEVICE MASTER SLAVE idHICH CHANNEL CilANNEL OPERATIONAL OPERATIONAL ACTUATION RELAY RELAY. SURVEILLANCE FUNCTIONAL UNIT CHECK CALIBRATION TEST TEST LOGIC TEST TEST TEST IS REQUIRED 3.
CONTAlletENT ISOLATION
'a. Phase "A" Isolation
- 1) Manual N.A.
N.A.
N.A.
R N.A.
N.A.
N.A.
1, 2, 3, 4
- 2) Safety Injection See 1 above for all Safety Injection Surveillance Requirements
- 3) Automatic Actuation N.A.
N.A.
N.A.
N.A.
M(1)
M(1)
Q 1, 2, 3, 4 g
Logic and Actuation Relays
- =
3 b.
Phase "B" Isolation
- 1) Automatic Actuation N.A.
N.A.
N.A.
N.A.
M(1)
M(1)
Q 1, 2, 3, 4 Logic and Actuation Relays
- 2) Reactor Building 5
R Q
N.A.
N.A.
N.A.
N.A.
1, 2, 3 Pressure-High-3 c.
Purge and Exhaust Isolation
- 1) Automatic Actuation N.A.
N.A.
N.A.
N.A.
M(1)
M(1)
(L) 1, 2, 3, 4 logic and Actuation M,y Relays
- 2) Containment Radio-S R
H N.A.
N.A.
N.A.
N.A.
1, 2, 3, 4 activity-High g
- 3) Safety injection See 1 above for all Safety Injection Survelliance Requirements.
.E F
9508040250 950728 PDR ADOCK 05000395 P
TABLE 4.3-2 (Centinued)
ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION -
SURVEILLANCE REQUIREMENTS TRIP ANALOG ACTUATING MODES FOR.
CHANNEL DEVICE MASTER SLAVE WHICH CHANNEL CHANNEL OPERATIONAL OPERATIONAL ACTUATION ' RELAY RELAY SURVEILLANCE FUNCTIONAL UNIT CHECK CAllBRATION TEST TEST LOGIC TEST TEST TEST. 15 REOUIRED 3.
CONTAINMENTISOLATION
- a. Phase "A" Isolation
- 1) Manual N.A.
N.A.
.N.A.
R N.A.
N.A.
N.A.
1,2,3,4
- 2) Safetyinjection See 1 above for all Safety injection Surveillance Require mr.nts.
- 3) Automatic Actuation N.A.
N.A.
N.A.
N.A.
M(1) -
M(1)
Q 1,2,3,4 Logicand Actuation Relays
- b. Phase "B" Isolation
- 1) Autorr.atic Actuation N.A.
N.A.
N.A.
N.A.
M(1)
M(1)
Q
'1,2,3,4 Logic arid Actuation Relays
- 2) Reactor Building 5
R Q
N.A.
N.A.
N.A.
N.A.
1,2,3 c Purge and Exhaust isolation
- 1) Automatic Actuation N.A.
N.A.
4.A.
N.A.
M(1)
M(1)
Q(2) -
1,2,3,4 Logicand Actuation a
Relays
- 2) ContainmentRadio-S R
M N.A.
N.A.
N.A.
N.A. -
1,2,3 activity-High
- 3) Safetyinjection See 1 above for all Safety injection Surveillance Requirements.
d e'
i
' INSTRUMENTATION TABLE 4.3-2 (Continued)
TABLE NOTATION (1) Each train shall be tested at least every 62 days on a STAGGERED TEST BASIS.
1 (2)
The 36 inch containment purge supply and exhaust isolation valves are scaled closed during Modes 1 through 4, as required by TS 3.6.1.7.
With these valves sealed closed, their ability to open is defeated; therefore, they are excluded from the quarterly slave relay test.
A 1
l i
1 SUMMER - UNIT 1 3/4 3-40 l
-..i..
l X
INSTRUMENTATION TABLE 4.3-2 (Continued)
TABLE NOTATION l
l l-(1)
Each train shall be tested atleast every 62 days on a STAGGERED TEST BASIS.
(2)
The 36 inch containment purge supply and exhaust isolation valves are sealed closed during Modes 1 through 4, as required by TS 3.6.1.7. With l
these valves sealed closed, their ability to open is defeated; therefore, they.
i are excluded from the quarterly slave relay test.
l l
SUMMER - UNIT I 3/4 3-40 Amendment No.
. DocumentContrilDesk
" *L
. Attachm:nt.II TSP 950009.
~
RC-95-0183 Page 1 of1~
SAFETY EVALUATION FOR REVISING THE SPECIFICATION FOR t
SLAVE RELAY TEST OF THE 36" PURGE SUPPLY ANDEXHAUSTISOLATIONVALVES i
VIRGIL C. SUMMER NUCLEAR STATION TECHNICAL SPECIFICATIONS Description of Amendment Reauest l
The Virgil C. Summer Nuclear Station (VCSNS) Technical Specifications (TS) 3/4.3.2, Engineered Safety Feature Actuation System Instrumentation, Surveillance i
Requirement 4.3.2.1, is being revised to exclude the requirement to perform the slave relay test of the 36" containment purge supply and exhaust valves on a quarterly basis while the plant is in Modes 1,2,3, or 4.
l l
Safety Evaluation The Design Basis of these valves is to open to purge containment during periods of i
shutdown. The intent is to remove most of the ambient heat and airborne radiation prior.
to opening containment for personnel access. The air from the Reactor Building passes i
through both high efficiency particulate absolute (HEPA) filters as well as charcoal adsorber filter banks before being released to the atme:@cre.
These valves permit sufficient air flow through the 36" piping to effect a rapid pur ge of the Containment Building prior to having extensive work activities commence. T2ese valves are opened primarily for personnel safety and comfort, and they are only used -
during a plant shutdown.
The 36" purge sup(ply and exhaust valves close automatically should the containment radiation monitor s)(RMG 17A' Reactor Building atmos 17B) alarm. Additionall, these airborne radiation alarm on the ere and ReactorBuilding purge exhaust moniter(s) (RMA 2, RMA 4). These functions h p prevent the release of radiation due to an accident in nLainment while these valves are open.
The only credible accident discussed in FSAR Chapter 15 that applies to these valves is a fuel handling accident inside containment (15.4.5.1). The analysis assumes the escaped gases are released instantaneously to the environment via the Reactor Building purge system. The analysis does not take credit for these valves nor for filtration or holdup time
'during release. The result of the analysis is acceptable and offsite doses are within the limits of10 CFR 100.
.i TS 3.6.1.7. requires that these valves be sealed shut during Modes 1,2,3, and 4. When sealed shut, these valves will not open via any signal.
TS 4.3.2.1. requires that this slave relay test be performed quarterly. This surveillance is i
accomplished for the 36" containment purge supply and exhaust valves by cycling the i
respective K615 relay. This will not provide assurance that the valve will perform its safety function since the valve is sealed closed. The proposed change will exclude the requirement to perform the K615 relay test (auto actuation logic and actuation relays -
slave relay test) on a quarterly basis while the plant is in Modes 1,2,3, or 4.
. Docum:nt Contril Desk-
~
Attachm ntJII-
- TSP 950009 i
RC-95 '0183 Page 1 of 2 NOSIGNIFICANT HAZARDS EVALUATION FOR REVISING TIIE SPECIFICATION FOR SLAVE RELAY TEST OF,THE 36" PURGE SUPPLY ANDEXHAUSTISOLATION VALVES VIRGIL C. SUMMER NUCLEAR STATION TECIINICAL SPECIFICATIONS Description of Amendment Reauest i
The Virgil C. Summer Nuclear Station (VCSNS) Technical Specifications (TS) 3/4.3.2, Engineered Safety Feature Actuation System Instrumentation, Surveillance.
Requirement 4.3.2.1, is being revised to exclude the requirement to perform the slave i
relay test of the 36" containment purge supply and exhaust valves on a quarterly basis while the plant is in Modes 1,2,3, or 4.
Basis for No Significant Hazards Consideration Determination South Carolina Electric & Gas Company (SCE&G) has evaluated the proposed changes to i
the VCSNS TS described above agamst the Significant Hazards Criteria of 10 CFR 50.92 and has determined that the changes do not involve any significant hazard for the following reasons:
1.
Does the change involve a significant increase in the probability of consequences of an accident previously evaluated?
No, the probability or consequences of an accident reviously evaluated would not be 3
increased since no credit is taken for the valves in b SAR Chapter 15.
The only credible accident discussed in FSAR Chapter 15 that applies to these valves is a fuel handling accident inside containment (15.4.5.1). The analysis assumes the escaped gases are released instantaneously to the environment via the Reactor Building purge system. The analysis does not take credit for these valves nor for filtration or holdup time during release. The result of the analysis is acceptable and offsite doses are within the limits of 10 CFR 100.
TS 3.6.1.7. requires that these valves be sealed shut during Modes 1,2,3, and 4.
When sealed shut, these valves will not open via any signal.
With these valves already in a shut position, neither the probability nor the consequences of an accident are increased.
2.
Does the change create the possibility of a new or different kind of accident from any j
previously evaluated?
.i
- No, the 36" containment purge exhaust and supply valves will not be placed in a i
condition different from that evaluated previously.
The only credible accident discussed in FSAR Chapter 15 that applies to these valves i
is a fuel handling accident inside containment (15.4.5.1). The ar.alysis assumes the escaped gases are released instantaneously to the environment via the Reactor Building purge system. The analysis does not take credit for these valves nor for
.. - ~.
I
./ Docum:nt Contral Desk
- Attachm:ntJII TSP 950009 RC-95-0183 Page 2 of 2 filtration or holdup time during release. The result of the analysis is acceptable and offsite doses are within the limits of10 CFR 100.
l Additionally, TS 3.6.1.7. requires that these valves be sealed shut during Modes 1,2, 3, and 4. When sealed shut, these valves will not open via any signal.
t 3.
Does the change involve a significant reduction in the margin of safety?
TS 4.3.2.1. requires that this slave relay test be performed quarterly. This surveillance is accomplished for the 36 containment purge exhaust and supply valves by cycling the respective K615 relay. This will not provide assurance that the valve will perform its safety function since the valve is sealed closed. The proposed change will exclude the requirement to perform the K615 relay test (auto actuation logic and actuation relays - slave relay test) on a quarterly basis while the plant is in Modes 1,2,3, or 4.
TS 3.6.1.7. reqitires that these valves be sealed shut during Modes 1 2,3, and 4.
When sealed shu t, these valves will not open via any signal. Since tilis relay would not be needed to supply a signal to place these valves in the closed position, the margin of safeby is not affected.
Based on the preceding analysis, SCE&G has determined that this change does not involve a significant hazards consideration.
1 i
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