ML20062D710
| ML20062D710 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 07/29/1982 |
| From: | GEORGIA POWER CO. |
| To: | |
| Shared Package | |
| ML20062D699 | List: |
| References | |
| TAC-55865, TAC-56522, TAC-56523, NUDOCS 8208060195 | |
| Download: ML20062D710 (13) | |
Text
._
ATTACHMENT 1 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 f-EDWIN I. HATCH NUCLEAR PLANT UNIT 2 PROPOSED CHANGES T0-TECHNICAL SPECIFICATIONS The proposed change to Technical Specifications (Appendix A to Operating License NPF-5) would be incorporated as follows:
Remove Page Inset Page 3/4 8-1 3/4 8-1 3/4 8-2 3/4 8-2 9
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3/4.8 ELECTRICAL POWER SYSTEMS 3/4.8.1 A.C. SOURCES A.C. SOURCES - OPERATING LIMITING CONDITION FOR OPERATION 3.8.1.1 As a minimum,.the following A.C. electrical ~ power sources shall be OPERABLE:
a.
Two physically independent circuits between the offsite transmission network and the onsite Class lE distribution system, and b.
Three separate and independent diesel generators, each with:
1.
A separate day tank containing a minimum of 900 gallons of
- fuel, 2.
A separate fuel storage tank containing a minimum of 32,000 gallons of fuel, and q
3.
A separate fuel transfer pump.
I APPLICABILITY:
CONDITIONS 1, 2, and 3.
ACTION:
a.
With either one offsite. circuit or one diesel generator of the above required A.C.
electrical power sources inoperable, demonstrate the OPERABILITY of the remaining A.C.
sources by performing Surveillance Requirements 4.8.1.1.1.a and 4.8.1.1.2.a.4 within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter;* restore at least two offsite circuits and three diesel generators ** to OPERABLE status within 72' hours or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
I b.
With one offsite circuit and one diesel generator of the-above required A.C. electrical power sources inoperable, demonstrate the OPERABILITY of the remaining A.C. sources by performing
- For the loss of the 2C diesel generator from 2:00 p.m. EST 07/27/82 thru l 2:00 p.m.
08/13/82, perform Surveillance Requirement 4.8.1.1.',.a at - least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, and perform Surveillance Requirement 4.8.1.1.2.a.4 at three day staggered intervals for diese! generators 2A and 18.
The provisions of Specification 3.0.4 do not apply for this change.
- For the loss of the 2C diesel generator from 07/27/82 thru 08/13/82, l
restore diesel generators 2A and 18 to Operable status.
The provisions of Specification 3.0.4 do not apply for this change.
HATCH - UNIT 2 3/4 8-1
ATTACHMENT 2 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNIT 2 PROPOSED CHANGES TO TECHNICAL SPECIFICATIONS Pursuant to 10 CFR 170.12 (c), Georgia Power Company has evaluated the attached proposed amendments to Operating License NPF-5 and has detennined that:
a)
The proposed amendment does not require the evaluation of a new Safety Analysis Report or rewrite of the facility license; b)
The proposed amendment does not contain several complex issues, does not involve ACRS review, and does not require an environmental impact statement; c)
The proposed amendment does not involve a complex issue, an environmental issue or more than one safety issue; d)
The proposed amendment does involve a single safety issue, namely, extension of the LC0 for one inoperable diesel generator.
e)
The proposed change is therefore a Class III amendment.
o
ELECTICAL POWER SYSTEMS LIMITING CONDITION FOR OPERATION (Continued)
ACTION (Continued)
Surveillance Requirements 4.8.1.1.1.a and 4.8.1.1.2.a.4 within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least one of the inoperable sources to OPERABLE status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or be in at least H0T SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and - in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Restore at least two offsite circuits and three diesel generators ** to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from the time of initial loss or be in at least HOT SHUTDOWN within the next 12 ' hours and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
c.
With two of the above required offsite A.C. circuits inoperable, demonstrate the OPERABILITY of three diesel generators by performing Surveillance Requirement 4.8.1.1.2.a.4 within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter, unless the diesel generators are already operating; restore at least one of the inoperable offsite sources to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
With only one offsite source restored, restore at least two offsite circuits to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from the time of initial loss or be in at least HOT SHUTD0WN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
d.
With two of the above required diesel generators -inoperable, demonstrate the OPERABILITY of the remaining A.C.
sources by performing Surveillance Requirements 4.8.1.1.1.a and 4.8.1.1.2.a.4 within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least one of the inoperable diesel generators to OPERABLE status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN with the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Restore three diesel generators ** to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from time of initial loss or be in at least HOT SHUTDOWN within the next 12'nours and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
SURVEILLANCE REQUIREMENTS 4.8.1.1.1 Each of the above required independent circuits between the offsite transmission network and the onsite Class lE distribution system shall be:
a.
Determined OPERABLE at least once per 7 days by verifying correct breaker alignments and indicated power availability, and b.
Demonstrated OPERABLE at least once per 18 months during shutdown by transferring, manually and automatically, unit power supply from the normal circuit to the alternate circuit.
- For the loss of the 2C diesel generator from 07/27/82 thru 08/13/82, l
restore diesel generators 2A and 18 to Operable status.
The provisions of Specification 3.0.4 do.not apply for this change.
HATCH - UNIT 2
'3/4 8-2
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ATTACHMENT #3 Page 1 cf g i
I SAFE 1Y EVALUATION FOR AC S0lRCES - OPERATING TECHNICAL SPECIFICATION CHANGE I.
BACKGROUND i
On July 27,1982, at 1:20 P.M EDT while perfoming nomal surveillance testing on diesel generator 2C it was determined that the Ntanber 8 cylinder upper connecting piston rod bearing had failed. At that.
time, diesel generator 20 was declared inoperable and the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> ACTION statement was invoked. Af ter exceeding the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> ACTION statement <. Uriit 2 must be placed in HOT SHUTDOW. Preliminary c
investigations revealed that an excess of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> will be required I
to return diesel generator 2C to OPERABLE status. Justification i
for an extension beyond the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> interval is provided in the bases below.
,4-II. REFERENCES Technical Specification 3.8.1.1 for Unit 2.
f
^
III. BASES _
g Presented below is an evaluation of the safety significance of extend-1 ing diesel RC LCO from 3 to 18 days. The systems analysis describes the impact of diesel 2C out on both units'and identifies the l
limiting event se~quence. The PRA e.valua. tion discusset the' probabilfty of occurrence of the limiting event sequence and analyzes the. impact.
of an 18 versus 3 day LCO. Finally, the reliability evaluation discusses the Hatch diesel performnce data as used in the PRA analysis l
and conpares it to some industry data.
A.
Systems Analysis The onsite standby AC power supply for Units 1 and 2 consists of l
five diesel generator units and supplies standby power to 4160-volt essential buses lE IF. IG. 2E. 2F. and 26. Diesel generators lA and IC supply Unit 1 essential buses 1E and 16. respectively.
l Diesel generators 2A and 2C supply Unit 2 essential buses 2E end I
2G, respectively. Diesel generator 1B is a shared facility and I
can supply either Unit 1 essential bus IF or Unit 2 essential I
bus 2F.
i An examination of Units 1 and 2 systems configuration with i
diesel 2C out is presented in Tables 1 and 2.
(Table 3 provides a list of the loads on each emergexy bus). Table 1 analyzes seven plant conditions assuming diesel 2C out with no single I
failure. Table 2 analyzes the same plant conditions with diesel 2C out and a single failure assumed. The results of these analyses show that for every plant condition except two, adequate core cooling capability exists; in all cases adequate core cooling exists for Unit 1.
The excepted cases involve LOSP combined with a specific recirculation line break which prevents R E injection in Unit 2.
The Unit 2 identified event
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Page 2 of 9 sequence leading to core melt was examined further using Pl:A methodology.
B.
PRA Evaluation Assuming that diesel generator 2C is taken out for maintenance, the DBA can be characterized by the loss of offsite power
. coincident with a LOCA along with the loss of ECC,S..
Thqselecte'daccidentsequencEwasquantifiedtodeterminethe-probability of core melt utilizing simplified fault tree analysis 5
techniques and plant specific and generic failure data from WASH-1400. The f ailure probabilities of LOSP, LOCA and the core spray on demand were derived from WASH-1400 and the probability of loss of diesci 2A on demand was derived from the plant specific analysis of the Hatch diesel system. The probability of LOSP was assumed as 0.2/ year based on generic data. It should be noted that there have been no loss of offsite power eyents at Plant Hatch. Thus use of the 0.2 value has the effect of making the risk assessment slightly conservative.
Table 4 depicts the probabilities for the individual events of the selected sequence and the probability of core melt at Unit 2 for the 3 day and 18 day LCO intervals. The core melt.
probabilities for Unit 1 were also calculated and found to.
be lower than Unit 2.
Therefore this discussion is. restricte'd s
to ' Unit 2 only, The core melt probability for the 3 day and 18 day interval ~1s l
l estimated as 5.0 x 10-9 and 3.0 x 10-8, respectively. These values indicate that the risk of core melt if the unit is operated for 18 days with diesel generator 2C down for i
maintenance is a factor of 6 times higher. The factor of 6 l
represents less than one order of magnitude and is insignificant from any risk assessment point of view.
I It must also be realized that the probability of core melt I
of 3.0 x 10-8 during the 18 day period in itself represents a very low risk compared to other forms of man-made risk..
Lastly, the p obability of core melt of 5.0 x 10-9/3da3 interval and 3.0 x 10-8/18 day interval is consistent with the accident i
sequence identified in Tagle 3.4.6A of the Limerick PRAstudy which is 1.
i day interval.
In light of the above it can be unequivocally stated that the risk from Hatch Nuclear Plant-Unit 2 if operated with diesel generator 2C in maintenance for a duration of 18 days is not significantly different from that if operated for a duration of j
3 days.
C.
Reliability Evaluation The probabilities of diesel performance used in the PRA study were based on Hatch specific data. An analysis of the data demonstrated good overall performance of the Hatch diesels.
M Page 3 cf S In Febru'ary 1982 an internal reliability study of the Plant Hatch diesel generators was completed. The object'ives of this study were to define and quantify problems with the diesel i
generators and to determine the failure rate of the diesel l
generators and compare this to accepted standards of diesel generator perfonnance to~ determine whether the Plant Natch- --
3 diesel generators have been performing adequately. This study was perfonned using Hatch specific reliability information submitted by Georgia Power Compahy to the NRC on October 9, 1981, in response to unresolved safety Issue A-44, Station Blackout.
The conclusions of th'is study are that the Plant Match diesel generators are more reliable than the national average. Tne weighted average failure rate of the five diesel generators.
is 2.7 percent, which is slightly better than an industry average of about 3 percent. Although no ge.wrally accepted industry average exists at this time, an average was developed using WASH-1400. Science Applications data !see EPRI report NP-2433) and fail'ure data from Alabama Power Company's Plant Farley.
It should be noted that this industry average failure rate of 3.0 percent is slightly better than the WASH-1400 failure rate of 3.2 percent.
The results of this study also, indicated that the percentage of time that the diesel generators are unavailable due to.
, maintenance did not appear to be large. The average unavailability due to maintenance for the five diesel generators is 1.3 percent. The Plant Hatch diesel generator failure rates and unavailability due to maintenance are provided in Table 5.
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.This study also pointed out that there are several reasons why a diesel generator could fail an operability test as defined by Regulatory Guide 1.108 yet still have provided power during an actual emergency such as:
a 1.
Failure to start but successful restart without modifications or maintenance.
2.
Start time too slow.
3.
Failure af ter successful start but restarted and completed test without modification or maintenance.
When unsuccessful tests in these categories are not considered the Plant Hatch diesel generators perforunnte improves significantly. For example, diesel generator failure is defined as the inability of the diesel generator system to start and run in one of the following situations:
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Page 4 ef 9 t
Type A - Unsuccessful congletion of a surveillance test, detennined by criteria of Regulatory Guide 1.108.
Type B - Unsuccessful surveillance test that would have been a failure to provide power had
- there been an actual emergency.
b The failure rates shown in Table 6 apply to situations
.t and B:
I This study covered approximately 5-1/2 years for Unit 1 and-approximately 3 years for Unit 2. ending June 1981. A survey of the diesel generators' performance since then shows that no significant degradation in failure rates has occurred.
Table 7 swanarizes diesel generator performance from June 1981 to June 1982.
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Page 5 cf 3 l
Plant Condition Case Uni t 1 Unit 2 IST EQU1PMENT BUSES AVAILABLE 1
LOSP LOSP Unit 1 - 4160V Buses 1E & 1G Q
Unit _2, __4Jf>0V Buses 2E & 2F 2
_.llniL1, - 4160V Buses 1E & 16 Unit 2 - 4160V Buses 2G, 2E. & 2F 3
No LOSP LOSP.
Unit 1 - 4160V Buses IF.1E, & 16 Unit ? - 4160V Buses 2E. 8 2F
~
4 LOSP LOSP Unit 1 - IB relpcate to LOCA Unit-4160V Buses 1E, LOCA No LOCA 1F, & 1G Unit 2 - Go to hot standby-4160V Bus 2E Sufficient time to reload diesel on Bus 2F li 5
LOSP LOSP Unit 1 - 4160V Buses 1E & 1G No LOCA LOCA Unit'AT60V Buses 2E & 2F 1B relocates to LOCA Unit 6
LOSP No LOSP Unit 1 - 4160V Buses 1E, IF 81G LOCA No LOCA
ifnTtT-T60V Buses 2E, 2F & 2G i
7 No LOSP LOSP Unit 1 - 4160V Buses 1E,16 & 1F No LOCA LOCA Unit 2 - 4J60V,)yuses 2E & 2F l
O 9
b TABLE 1 SLMMRY OF POSTULATE _D.PL ANT CONDITIONS WITH DIESEL GENERATOR 2C OUT FOR MAINTENANCE OR TEST WITH NO SINGLE FAJLURE ASSUMED I
4 I
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ei.
.s Assuree Plant Condition loss of Case Unit 1 Unit 2 Bus ESF Equipment Remaining 1
LOSP LOSP 2F Unit 1 - 4160V Buses lE and 1G Unit 2 - 4160V Bus 2E 2
LOSP No LOSP Any Bus Unit 1. 4160V Buses Any 2 of 3 (BothUnits)
Unit 2
'4160V Buses Any 2 of 3 9
3 No LOSP LOSP 2F Unit 1 - 4160V Buses IE, 1F, and 16 j
' Unit 2 - 4160V Bus 2E i
1E or Unit 1.18 relocate to LOCA Unit -
4 LOSP LOSP 1G Bus IF & 1E or 1G LOCA No LOCA 2E Unit 2 - Go to hot standby -
l Sufficient time to reload diesel on Bus 2F IE or S
LOSP LOSP 1G Unit 1 - 4160V Buses IF A 1E or 16 _ _
No LOCA LOCA 2F Unit 2 - 4160V Bus 2E lE,1F
/
6 LOSP Wo LOSP of 1G Unit 1 - 4160V Suses 1E. IF & )G (2_of 3)
,4160V Buses 2E, 2F 4 2G
{
or 2G 1E,1F 7
No LOSP LOSP or 1G Unit 1 - M1 Ovses Avellable (2 of 3)
No LOCA LCCA 2F Unit 2 - 4160V Bus 2E TABLE 2 -- SL8 MARY OF POSTULATED PLANT CONDITI(MS WITH
[
DIESEL GENERATOR 2C OUT FOR MAINTENANCE OR TEST
[
WITH SINGLE FAILURE ASSUMED o,
l I
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TABLE 3 LOADS _ON EMERGENCY BUSES I
Unit 1 Unit 2
~
I 4160 Vol' Bus 2t,
t 4160 Volt Bus 1E _
Core Spray Pump 1A
' Core Spray P m p 2A RHR Service Water Pmp 1A RHR Pump 2A RHR Pump 1A RHR Service Water P6mp 2A CRD Pep 1A CRD P ep 2A Fire Pump Plant Service Water Pap 2A 4160-600 V. Sta. Serv. Transf.1C Drywell Chiller Unit 2A Plant Service Water Pump 1A 4160-600 Volt Sta. Serv. Transf. FC 4160 Volt Bus 1F 4160 Volt Bus 2F 4
RR service Water P a p 1C..
,RHR Pup 2D RHR Pump 1D RRR Service Water Pump 2C CRD Puun 1B CRD Pump 2B 4160-600 v. Sta. Serv. Transf.1CD Plant Service Water Pmp 2C' Plant Service Water Pung it Plant Service Water Pump 20 Plant Service Water Pump 1D 4160-600 Volt Sta. Serv. Trans. 2F1
('.i 4160-600 V. Transf. (Mcc-lB) 4160-600 Volt Sta. Ser,v. Tr'ans. 2F2 4160-600 Volt Sta. Serv..Trans'. 2CD 4160 Volt Bus 1G 4160 Volt Bus 2G R E Service Water Pune 1B BR Pump 2B RHR Service Water Pep 1D R R Service Water P g 25 RHR P op 1B RR Service Water Pump 2D 4160-600 V. Sta. Serv. Transf.1D Core Spray Pianp 2B Plant Service Water Pump 1B Plant Service Water Pap 28 Core Spray P op 1B Drywell Chiller Unit 28 4160-600 Volt Sta. Serv. Transf. 2D 0
9
Page B of 9
\\
TABLE 4 Probabilities E nt Probability of LOSP 0.2/ year
- I Probability of a Large LOCA 1 x 10'4/ year *'
~2***
l Probability of Loss of DG 2A on Demand 2.71 x 10
~3**
Probability of Loss of Core Spray Pump 2 x 10 on Demand
-9 Probability of a Core Melt at Unit 2 5.0 x 10 for 3 day Interval 3.0 x 10-8 Probability of a Core Melt at Unit 2 for 18 Day Interval
~
i a
- There have been no loss of offsite power events at Plant Hatch g
g The value of 0.2 failures / year represents a generic num6er derived from WASH-1400.
- This value was derived from WASH-1400.
f E
- This value was derived from a plant-specific analysis of the j
Hatch diesel generator system.
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Page 9 of 9 l}
TABLE 5 s
Test Failure Rate Unavailability Diesel Generat_or, (Percent)..
(Percent) 1A 2.19 1.01 f
1.C
- 3.45 1.39 B
3.13 2.87 2A 1.52 0.70 2C 2.49 0.44 Weighted Average 2.71 l.30 1
j t.
TABLE 6 t
1 Type A Type B Unsuccessful Test Failure if Deergency Of esel Generator _
(Percent)
(Percent) 1A 2.19 0.31' 1C 3.45 1.03 B
3.13 2.34 2A 1.52 0.76 2C 2.49 1.24 Weighted Average f.71 1.24 TABLI 7 Failure Rate Die _sel Generator Attempts Failures _
(Percent) 1A 41 0
0 1C 36 0
0 1
0.208 8
48~
0 0
2A 15 2C 141 4
2.84 1.78 Weighted Average
.