ML20106A984
| ML20106A984 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 09/18/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20106A982 | List: |
| References | |
| NUDOCS 9209300179 | |
| Download: ML20106A984 (3) | |
Text
a no
- /
m\\
O*
UNITED STATES c.
,{
i NUCLEAR REGULATORY COMMISSION f,
o 2
WAsHINoToN, D C. 20555 A
y
- /
g'...++
SAFETY EVAlVATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION Efi3TED TO AENDMENT N05,134 ANg 138 TO LA1]!ITQP_f RATING LICENSE NOS. DPR-24 AND DPR-27 f
RLSCLNSIN ELECTRIC POWER COMPANY POINT H[A(ti NUCLEAR PLANT. UNIT NOS. 1 AND 2 DOCKET NOS. 50-761 AND 50-301
1.0 INTRODUCTION
By letter dated September 22, 1989, Wisconsin Electric Power Company (WEPCo) proposed revising the Point Beach Nuclear Plant Technical Specifications by adding limiting conditions of operation to prescribe when the 680 volt afeguard buses may be tied together, when the 4160 volt safeguard buses may Le tied together, and when these safeguard buses must be powered from their normal supply.
The normal line-up of the safety-related buses is with all tie breakers open.
Prior to this amendment application the technical specifications did not address the use of the tie breakers.
By letter dated August 25, 1992, ti.e licensee submitted, information supplemental to the application.
This information further clarified the conditions under which the buses could be tied together, but did not change the scope of the amendment request or have any bearing on the proposed determination of no significant hazards consideration.
2.0 EVALUATION Each unit of Point Beach has two 480V AC safety buses [1(2) B03 and 1(2) 804) which are supplied through step down transformers, from two 4.16kV safety buses
[1(2) A05 and 1(2) A06].
The A05 and A06 safety buses are normally supplied from
[i(2) A03 and 1(2) A04), 4.16kV non-Class lE buses.
In the event of a loss of offsite power when Emergency Diesel Generators (EDGs) are required, the A05 safety bus will receive power from EDG G01 and the A06 safety bus will receive power from EDG G02.
The 480V (B03 and B04) and 4.16kV (A05 and A06) safety buses have a normally open tie breaker.
Ther are no LCOs in Point Beach TS Section 15.3.7 which limit the time when the bus tie breakers may be closed.
The closing of any one of the tie breakers compromises the electrical syr'em independence and redundancy.
WE's proposed TS changes are based on the guidance of Revision 4 of NUREG-0452, Standard Technical Specification for Westinahouse Pressurized Water Reactors (STS).
The STS requires an independent lineup of the safety buses with the tie breakers between redundant buses to be open. However, if a tie breaker is closed, LCOs are in effect, i.e., deviation from the normal lineup for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold Shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
v209300179 920918 PDR ADOCK 05000266 p
~
l l
t ker and ing the operation of the bus tie brea the plant j
i tive administrative constraint oninvolve any change The proposed addition of LCOs cancern hutdown as the safety buses will set restr cThe proposed TS changes date a unit hot standby or cold sb lity or conseque will not operation of the unit except to man There is no increase in the proba ir the possibility of creating operation.
t previously evaluated.
acident previously evaluated, o outlined above.
kind of accident from any accidenincrease the safety ma nits' operations.
king one or conditions to be met prior to maAll safety buse b
kers are h
Proposed TS 15.3,7. A.1 addresses t e and both units A05/A06 bus tie-reawith l conditions.
both reactors critical under normaenergized f rom their n d B03/604 bus tie-breakers are open l
dent and redundant trains.
t for the removed from their cubicles an Black Plant startup where one reac power removed to ensure indepen
[I t
Proposed TS_L5JE is essentia abnormal conditions including the LCOs and the operability oOne pair of buses, A05 f the safety critical.
fueling shutdown.
h gh their Proposed T1_L517_J11e addresses d wn unit may be tied together t rouThe L for buses during one unit in cold or re A06 or B03 and 804 for that shut o nce of the essential buses, hours.
con on tie breaker for up to 8 limited time to allow testing unit is fully defueled the condition when a d B04 may be transformers.
Proposed TS 15.3.7.B lJ addressesdefueled unit A05 and A ker provided either:
and one pair of buses fer thetied together by their tie-brea that the loads remain or can be f the t cause a potential overload oThe emoved An evaluation is performed to show energized by the buses will no 1
ating unit.
associated diesel generator.from service shall be e fuel A single train of spent fuel coo ker and loss of both buses in the 2.
fire of a single f ailure of a tie-breainventory can be mainta Pcol.
detue:ed unit, the fuel pool waterThe fire suppression system is supp In t u dition for suppression water.
more conservative limiting con pump.
The staff finds that the TS imposes afore, accept able.
plant operatic, and are, there of ficial was ST ATE CONSULT AT IONregulations, the Wisconsin StateThe State 3.0 In accordance with the Commission'sof the amendm notified of the prop ^ sed issuance comments.
I
The proposed addition of LCOs concerning the operation of the bus tie breaker and the safety buses will set restrictive administrative constraint on-the plant operation.
The proposed TS changes will not involve any changes in the physical operation of the unit except to mandate a unit hot standby or cold shutdown as outlined above.
There is no increase in the probability or consequences of an-l accident previously evaluated, or the possibility of creating a new or different kind of accident from any accident previously evaluated.
The proposed LC0' will increase the safety margin of the units' operations.
Proposed TS 15,3.7.A.] addresses the conditions to be met prior to making one both reactors critical under nc mal conditions. All safety buses will be energized from their normal supply and both units A05/A06 bus tie-breakers are removed from their cubicles and B03/B04 bus tie-breakers are open with control.
power removed to ensure independent and redundant trains.
Proposed TS 15.3.7. A.2 is essertially identical to TS 15.3.7. A.1 except for the abnormal conditions including Black Plant startup where one reactor may be made critical.
Proposed TS 15.3.7 B.I.e addresses the LCOs and the operability of the safety buses during one unit in cold or refueling shutdown.
One pair of buses, A05 and A05 or 803 and B04 for that shutdown unit may be tied together through their common tie breaker for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
The LCOs allow abnormal bus lineups for limited time to allow testing / maintenance of the essential buses, breakers, and transformers.
Proposed TS 15.3.7.B 1.f addresses the condition when a unit is fully defueled and one pair of buses for the defueled unit A05 and A06 or 803 and B04 may be tied together by their tie-breaker provided either:
1.
An evaluation is performed to show that the loads remain or can be energized by the buses will not cause a potential overload of the associated diesel generator.
The applicable LC0 of the equipment removed from service shall be entered for operating unit.
2.
A single train of spent fuel cooling is adequate to cool the spent fuel pool.
In case of a single failure of a tie-breaker and loss of both buses in the defueled unit, the fuel pool water inventory can be maintained with fi~ e r
suppression water. The fire suppression system is supplied by a diesel p.owered pump.
The staff finds that the TS imposes a more conservative limiting condition for plant operation and are, therefore, acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Wisc-,in State' official was-notified of the proposed issuance of the amendment.
The state official had no comments.
i i
a l i 4
4.0 ENVIRONMENTAL. CONSIDERAT10B j
j--
These amendments involve a change in the installation or use of a facility t
component located within the restricted area as defined in 10 CFR Part 20 or change an inspection or surveillance requirement.
The staff bas determined that 4
the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that i
there is no significant increase in individual or cumulative occupational radiation exposure.
The Commission has previously published a proposed finding l
that these amendments involve no tignificant hazards cons;deration and there has been no public comment on such finding (56 FR 31445). Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR s51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no envircnmental impact statement or environmental assessment need be prepared in connection with the l
issuance of these amendments.
5.0 C_0RC VS10N 0l l
The staff has concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the public will-not be endangered by operation in the proposed manner, (2) such activities will be L
conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
[
Principal Contributor.
S. Saba l
Date:
September 18, 1992 I
i --
l l
l l
l
-