ML20084L916
| ML20084L916 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 04/25/1984 |
| From: | DUQUESNE LIGHT CO. |
| To: | |
| Shared Package | |
| ML20084L894 | List: |
| References | |
| NUDOCS 8405150122 | |
| Download: ML20084L916 (4) | |
Text
c;
(
I ATTACHMEllT A
(;
Remove page:
3/4 4-2 ll Insert page 3/4 4-2 t.
l-l.
~
L i
i I
.t k
e 9405150122 840425 PDR ADOCK 05000334 P
PDR t
REACTOR COOLANT SYSTEM ACTION (Continued) b)
Place the following reactor trip system ^ channels, associated with the loop not in operation, in their tripped conditions:
1.
Overpower 4 T channel 2.
Overtemperature6T channel c)
Change the P-8 interlock setpoint from the value specified in Table 3.3-1 to:
6 71% of RATED THERMAL POWER when the reactor coolant stop valves in the nonoperating loop are closed.
d)
Periodic surveillance testing of the instrumentation on the isolated loo'p is not required while the loop remains isolated.
2.
THERMAL POWER is restricted to:
f 66% of RATED THERMAL POWER when the reactor coolant stop valves in the nonoperating loop are closed, b.
With one reactor coolant loop and associated pump not in operation, subsequent STARTUP and POWER OPERATION at or below 31% of RATED THERMAL POWER may proceed provided the following reactor trip system channels, associated with the loop not in operation, have been placed in their tripped conditions with the reactor suberitical:#
1.
Overpower aT channel 2.
Overtemperature AT channel c
These channels may be placed in the bypass condition for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> during surveillance testing of the overpower and overtempera-ture AT channels of the active loops.
BEAVER VALLEY - UNIT 1 3/4 4-2 PROPOSED WORDING l
l l
~.
I i'
t r
i 4
ATTACHMENT B l
Safety Evaluation Proposed Change Request No. 35 Revision 1 amends our previous submittal dated October 27, 1978 concerning N-1 loop Technical Specifications.
~
Description and Purpose of Change i
During a technical specification review, it was determined that specification 3.4.1.1 does not address operation between the P-7 and P-8 power levels for N-1 loop operation.
Overpower delta T and over-tenperature delta T protection nust be provided at all times for 7
power levels above P-7.
An overpower or over-tenperature delta T signal t
in two out of three loops, during N-loop operation, will cause a reactor trip, thus, if detection fails in one loop, the other two -loops will provide 2/3 logic protection.
However, in N-1 loop conditions, the i
isolated loop will.not generate a signal and if detection in one of the l
active loops fails, the 2/3 logic would be defeated since only 1/3 i
+
signals would be available.
'Iherefore, to provide the - pro' ction
[
w L
necessary during N-1 loop operation, the isolated loop overpower and i
over-tenperature delta T channels must be tripped when operating between the P-7 and P-8 power levels, j
In response to the concerns addressed above, Action statement a.2.b i
has been irwated into specification 3.4.1.1-to provide the necessary l
)
reactor prei=ction system requirenents for N-1 loop operation.
i 4
Y Basis I
b 1.
Is the probability of an occurrence or the consequences of an f
accident or malfunction of equipment.inportant to safety as previ-j ously evaluated in the UFSAR increased? jio, l
The proposed change reflects the UFSAR requirements for N-1. loop l
operation. 'the Technical Specifications will require _ the operator-4 to place the isolated loop reactor trip bistables in the tripped i
condition.- 'Ihe change provides for N-1 loop operation reactor trip i
i ywiection and is consistent with UFSAR Section 7.2, Reactor Trip System and Figure 7.2-1, Sheet 5 Iogic Diagram.
1
[
2.
Is the probability for an accident or malfunction of a different i
~
type than previously evaluated in the UFSAR created? }30, Reason:-
i j.
The UFSAR Section 14 does not address N-1 loop operat: ion for all j
probable accidents, our previous sutznittals included the additional accident analysis applicable to N-1 loop operation. 'Ihe accident I
i l
t P
+
c-,
y
<+, - --y y,
,,,.r=
w-,-
v----,,ww.%e--
,~
--wa e n t-4 w
+ - + +,,
--,~~~-w-~
w++-tm.w.--rw,e e w-er *-
-,,-r-me r-5
-w=<w,--
7-analysis required to cmplete the Section 14 analysis for N-1 loop operation will be incorporated into the UFSAR following approval of the N-1 technical specification change.
The N-1 loop accident analyses conclude that in the event of an accident, the plant limiting parmeters are maintained within acceptable limits. This proposed technical specification change reflects the assuroption used in the accident analyses, that the isolated loop reactor trip system bistables are tripped prior to plant operation in an N-1 loop configuration.
3.
Is the margin of safety as defined in the basis for any Technical Specification 2. 4 M ? No.
Reason:
The technical specification bases adequately address N-1 loop operation.
Since this proposed change is being made to reflect assmptions used in. the N-1 analyses, the margin of safety as defined in the hchnical Specification bases will not be r W M.
4.
Based on the above, is an unreviewed safety question involved? No.
Conclusion The proposed change reflects the assurrptions used in the UFSAR system description and accident analysis for N-1 loop operation.
This change does not involve physical change to plant safety related systems, omponents or structures, will not increase the consequences of an accident previously analyzed nor create the possibility of a malfunction different than previously evaluated in the UFSAR.
Therefore, it is concluded that, since the change does not involve an unreviewed safety question in accordance with 10GR50.59,- the p1.psed change does not constitute a significant hazards consideration.
Based cm the consideration above, the proposed change has been determined to be safe and does not involve in unreviewed safety ques-l tion.
(
(
i I
l I
i i
i 5
E _