ML17139C975
| ML17139C975 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 02/08/1985 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML17139C974 | List: |
| References | |
| NUDOCS 8503080009 | |
| Download: ML17139C975 (8) | |
Text
~
~
UNITED STATES
'UC LEAR R EG ULATOR Y COMMISS ION WASHINGTON. D. C. 20555 SAFETY EVALUATION AMENDMENT NO.
31 TO NPF-14 AND AMENDMENT NO.
7 TO NPF-22 SUS UEHANNA STEAM ELECTRIC STATION, UNITS 1 AND 2 DOCKET NOS. 50-387 AND 50-388 Introduction The licensee proposed amendments to the Susquehanna SES Unit I and Unit 2 Technical Specifications in order to avoid a forced shutdown of Unit 2 durinq the Unit I first refueling outage.
Certain common loads for Susquehanna Units 1 and 2 are powered from a Unit 1 125-volt DC supply; therefore, Unit 2 currently depends on a Unit I, 125-volt DC system tn support common loads and, therefore, Unit 1
DC system is listed in the Un'it 2 Limiting Condition for Operation (LCOs).
Since Unit I battery load profile testing must be performed during the first refueling outage, an ACTION statement must he entered in the Unit 2 Technical Specifications.
The battery load profile testing cannot be performed within the two hours allotted in the ACTION statement (LCO) and, therefore, the required testing will force a Unit 2 shutdown.
Evaluation The licensee has developed a system modification consisting of a common load transfer scheme which will allow common loads to be powered from a 125-volt DC source on either unit through the use of manual transfer switches.
The feeder breakers of the DC source supply are not only a common load, but also a Unit 1 load.
Therefore, once the common loads including the Unit I loads have been transferred to the Unit 2 DC source, the Unit 1 loads (hereafter called "tag along loads" ) will be energized from a Unit 2 DC source.
In order to maintain division/channel separation, all Class 1E loads will be transferred between the corresponding Unit I and Unit 2 DC divisions.
The proposed Unit 1 technical specification changes to support the design changes to accomplish the purpose of avoiding forced shutdown of Unit 2 are described as follows:
a.
Pages 3/4 8-10:
The Unit 2 batteries, from which common and "tag along loads". may now be powered, are added to the LCO.
A footnote is provided to remove them as LCO requir'ement under situations when they are not supporting Unit I operation.
ACTION a is revised to affect Unit I
,,equipment only.
ACTION,b, is additionally provided to cover the common 0009 8~ 00387 p08
'S008 Oem 050 PaR g9 p
/
t
(
o'(f C,"
b.
co d.
e.
and "tag along. load" transfer in the event that a Unit 2 DC system supporting Unit I operation is inoperable.
ACTION c is provided to cover the realignment of Unit I 1oads to their normal Unit 1 source once that source has been restored to OPERABLE status.
Also ACTION b has been relettered as ACTION d.
Page 3/4 8-11:
ACTION c has been relettered as ACTION e..
Page 3/4 8-12:
The load profile for the Unit 1 Channel "B" battery has been revised to provide margin for future load additions, should they occur.
Insert B provides the load profiles for the Unit 2 batteries that are not required by the revised LCO.
Page 3/4 8-15:
See discussion for above item a.
Page 3/4 8-16:
ACTIONS c and d have been relettered.
Page 3/4 8-. 17:
As in the above discussion for item a, required Unit 2 equipment has been added to the LCO with a footnote to govern when it is required to support Unit I operation.
g.
Page 3/4 8-18:
As discussed in item a. for sources, appropriate ACTION statements have been proposed on insert D for the affected DC loads group.
h.
Page 3/4 8-20:
See discussion on item f.
Page 3/4 8-21:
"And/or" has been revised to just "or" for consistency with the LCO requirement on page 3/4 8-20.
Insert E is pr vid d i
fol controls over common load transfer and restoration of normal alignment.
For the Unit 2 technical specifications, similar changes are proposed to each section.
The only significant differences are on ACTION statements in the Unit I technical specification which cover the restoration of the normal Unit 4 alignment with respect to Unit I loads (tag along loads).
Since no Unit 2 load
's being transferred due to this change, such an ACTION is not required in the Unit 2 specifications.
The proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated, for the following reasons:
Each unit has four independent '125-volt DC power sources.
The FSAR 1
shows that a uni s.
e ana ysis inoperable.
t can be safely shut down with any one 125-volt DC power source Based on the revised design, one 125-volt DC source would f il d t
f lt in a Uni't I tag along load sf both upstream protective devices failed a
ue:
o a au (postulated worst condition).
The more practical result of a fault on a "taq along load" would be loss of an individual circuit.
Therefore, the most probable failure is much less severe than the loss of an entire power source, which has been previously evaluated.
V 1
~
l Finally, the Unit 2 DC systems have been analyzed and do have. suff' nt capacity to operate all necessary loads for the design basis interval of four hours, after loss of AC power and assuming the loss of the battery chapger.
The probable failure as a result of the revised design is within the. bounds of the FSAR analysis, and battery capacity is sufficient to meet design loads.
Therefore, no new or different failure possibility exists.
j The staff has reviewed the design modification and its associated technical specification changes to avoid the forced shutdown of Unit 2 during='the Unit 1
refueling outage, and as a result of our evaluation we find that proposed changes to the technical specification, 3/4.8.2 DC Sources, and 3/$
- 8.3'nsite Power Distribution Systems, are acceptable.
~
~
Environmental Consideration 4~---
'his amendment involves a change in the installation or use of a'.facility component located within the restricted area as defined in 10 CFR~<Part 20.
The staff has determined that the amendment involves no significaqt increase in the amounts, and no significant change in the types, of any effluents.that may be released offsite, and that ther e is no significant increase in indivi-dual or cumulative occupational radiation exposure.
The Commissi5h has previously issued a proposed finding that this amendment involves no signi-ficant hazards consideration and there has been no public comnent on such finding.
Accordingly, this amendment meets the eligibility criterf8-.Nor categorical exclusion set forth in CFR 51.22(c)(9).
Pursuant to 10 CFR'51.22(b) no environmental impact statement or environmental assessment need be'repared in connection with the issuance of this amendment.
- r,-,,
Conclusion We have 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, and (2)'..such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the co+ron. defense and security or to the health and safety of. the public.
Dated: FEB 0 8 SS5
1 J
F A
w 'Pt I Ql
~'v 1i
-, '- '.,J "AK~R~~'"-'-'e b.
p@f'$."g~>~acti.t~>"'~
r'ati s<<~~~'>'
,>a>5qu ~(c
4 FEB 08 j985 AMENDMENT NO. 31 TO FACILITY OPERATING LICENSE NO. NPF-14 AND AMENDMENT NO. 7 TO'FACILITY OPERATING LICENSE NO. NPF SUSQUEHANNA STEAM ELECTRIC STATION, UNITS I AND 2 RESPECTIVELY DISTRIBUTION:
Docket Fi1e'i S D -gs'7
'RC PDR Local PDR PRC System NSIC LBP2 Reading EMylton MJCampagnone TNovak JSaltzman, SAB OELD, Attorney CMiles KDenton JRutberg AToalston MMiller, LFMB NGrace EJordan LHarmon DBrinkman, SSPB TBarnhart(4)
P f)f, a~ s l