ML17306A581
| ML17306A581 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 03/16/1992 |
| From: | Zimmerman R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| References | |
| NUDOCS 9203230167 | |
| Download: ML17306A581 (8) | |
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~O ky*y4 Docket No. 50-529 UNITED STATES NUCLEAR REGULATORYCOMMISSION REGION V 1450 MARIALANE WALNUTCREEK. CAUFORNIA94596-5368 March 16, 1992 Arizona Public Service Company P. 0.
Box 53999, Sta.
9012
- Phoenix, Arizona 85072-3999 Attention:
Hr. William F.
Conway Executive Vice President, Nuclear Gentlemen:
SUBJECT:
REGION V TEHPORARY WAIVER OF COMPLIANCE TO PALO VERDE UNIT 2 TECHNICAL SPECIFICATION (TS) LIHITING CONDITIONS FOR OPERATION (LCO) 3.5.2 - Emergency Core Cooling System (ECCS),
TS 3.6.2. 1-Containment Spray System (CSS),
TS 3.7. 1.2 Auxiliary Feedwater System (AFS),
TS 3.7.3 Essential Cooling Water System (ECWS),
and TS 3.7. 11 - Shutdown Cooling System (SDCS)
I This letter documents a temporary waiver of compliance to the subject technical specifications for Facility Operating License No. NPF-51 that was verbally granted on Harch 15, 1992.
Region V reviewed your requests for a temporary waiver of compliance, dated Harch 13, 14, and 15, 1992.
Technical Specification (TS) 3.5.2 Limiting Condition for Operation (LCO) action statement
- requires, while the plant is in Modes 1, 2, and 3 with one ECCS subsystem inoperable, restoration of the inoperable subsystem to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 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 hot shutdown within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The TS LCO action statements for the remainder of the technical specifications noted in the requests require similar time restrictions for inoperable trains.
Your submittals concluded that the extension, of the TS LCO action statements from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 93 hours0.00108 days <br />0.0258 hours <br />1.537698e-4 weeks <br />3.53865e-5 months <br />, in order to facilitate diagnostic testing and corrective maintenance on train A of the ECWS heat exchanger, would not significantly affect plant safety.
Region V, with the concurrence of the Office of Nuclear Reactor Regulation, concluded that a temporary waiver of compliance of the TS 3.5.2, TS 3.6.2. 1, TS 3.7. 1.2, TS 3.7.3, and TS 3.7. 11 LCO action statements to extend the maximum inoperable time limit to 93 hours0.00108 days <br />0.0258 hours <br />1.537698e-4 weeks <br />3.53865e-5 months <br />, would.not negatively impact public health and safety for the following reasons:
Interim measures were established to ensure that no interruption of offsite power to Unit 2 occurs while in these TS LCO action statements.
All activity in the switchyard which could affect Unit 2 was suspended and no other work was performed or vehicular access allowed without the specific review and approval of the Vice President, Nuclear Production.
05000529' 9P03ib PDR ADDCK P
/ED~
L I
Hr. William F.
Conway March 16, 1992
~
-;Based upon -current seasonal conditions and compensatory measures which
-could be taken to restore normal heating, ventilation and air conditi'oning,(HVAC) for the train A.and B systems and components, the unavailability of essential cooling water and essential chilled water was not expected to result 'in the failure of train A components necessary for safely shutting down the plant.
Additional cooling paths were available to support the operation of the shutdown cooling system (SDCS).
The train A SDCS pumps (i.e.,
LPSI and
. CS pumps) could be cross-connected 'to the train 8
SDCS to use the
. -operable train B SDCS-heat -exchanger.
If neither train of the essential cooling water system
{ECWS) was available for performing the shutdown cooling functions, the -nuclear cooling water system (NCWS) could also be
'ross-connected to ihe desired ECWS train to provide a heat sink for shutdown cooling.
Based on the licensee's probability risk analysis, the increase in core
---damage probability associated with 'shutting" down the plant (i.e.,
2.9 E-6) was more than the increased risk associated with continuing the TS LCO action statement another 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br /> (i.e., 0.73 E-6).
This waiver was granted to be in effect from 1525 HST on March 15, 1992 to 1225 HST on March 16, 1992.
The licensee completed the work on train A of the
" 'ECWS=and: exit&'44e"TS XCO action statement at-1754 HST on March 15, 1992.
-Sincerely,
"- --R. P.,Zimmerman, Dire tor Division of Reactor Safety
'"and 'Pro'jects
,CC:,.J.. Taylor, EDO T. Hurley, NRR
--J. Mart'in, RV
..J...Lieberman,.
OE J. Partlow, NRR B. Boger, NRR
--M. Virgilio, NRR T. quay,- NRR C.- Trammell,. NRR K. Thompson, NRR H. Boyle, NRR
I
Hr. William F.
Conway March 16, 1992 Based upon current seasonal conditions and compensatory measures which could be taken to restore normal heating, ventilation and air conditioning (HVAC) for the train A and B systems and components, the unavailability of essential cooling water and essential chilled water was not expected to result in the failure of train A components necessary for safely shutting down the plant.
Additional cooling paths were available to s'upport the operation of the shutdown cooling system (SDCS).
The train A SDCS pumps (i.e.,
LPSI and CS pumps) could be cross-connected to the train B SDCS to use the operable train B SDCS heat exchanger.
If neither train of the essential cooling water system (ECWS) was available for performing the shutdown cooling functions, the nuclear cooling water system (NCWS) could also be cross-connected to the desired ECWS train to provide a heat sink for shutdown cooling.
Based on the licensee's probability risk analysis, the increase in core damage probability associated with shutting down the plant (i.e.,
2.9 E-6) was more than the increased risk associated with continuing the TS LCO action statement another 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br /> (i.e., 0.73 E-6).
This waiver was granted to be in effect from 1525 HST on March 15, 1992 'to 1225 HST on March 16, 1992.
The licensee completed the work on train A of the ECWS and exited the TS LCO action statement at 1754 HST on March 15, 1992.
Sincerely, cc:
J. Taylor, EDO T. Hurley, NRR J. Hartin, RV J.
Lieberman, OE J. Partlow, NRR H. Boyle, NRR R.
P.
Zimmerman, Director Division -of Reactor Safety and Projects B. Boger, NRR H. Virgilio, NRR T. Quay, NRR C. Trammell, NRR K. Thompson, NRR CVanDenburgh SRichards 03/16/92*
03/16/92*
HVirgilio KPe ns 03/i4/92 03$$ /92 RZimme ma 03((, /92 S
NO
[SEND TO DCS
]
SEND TO PDR ]
YES NO YES NO
- See previous concurrences
r I
(
I
Hr. William F.
Conway
~
Based upon current seasonal conditions and compensatory measures ich could be taken to restore heating, ventilation and air conditi ing (HVAC) for the train A and B systems and components, the una ilability of, essential cooling water and essential chilled water was ot expected to result in the failure of train A components necessary or safely shutting down the plant.
~
Additional cooling paths were available to support he operation of the shutdown cooling system (SDCS).
The train A SDC pumps (i.e.,
LPSI and CS pumps) could be cross-connected to the train SDCS to use the operable train B SDCS heat exchanger.
If nei er train of the essential cooling water system.(ECWS) was available f performing the shutdown cooling functions, the nuclear cooling wat r system (NCWS) could also be cross-connected to the desired ECWS trai to provide a heat sink for shutdown cooling.
Based on the licensee's probability isk analysis, the increase in core damage probability associated with shutting down the plant (i.e.,
2.9 E-6) was more than the incre ed risk associated with continuing the TS LCO action statement another 1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (i.e., 0.73 E-6).
This waiver was granted to be in e feet from 1525 HST on Harch 15, 1992 to 1225 HST on March 16, 1992.
The icensee completed the work on train A of the ECWS and exited the TS LCO acti n statement at 1754 MST on March 15; 1992.
Sincerely, cc:
J.
T.
J.
J.
J.
H.
Tayl or, DO Murle,
- Partlow, NRR
- Boyle, NRR R.
P.
Zimmerman, Director Division of Reactor Safety and Projects B. Boger, NRR H. Virgilio, NRR T. Quay, NRR C. Trammell, NRR K. Thompson, NRR CVa en 03/
h SRichards 03/yQ/92 HVirgili o 03/
/92 KPerkins 03/
/92 RZimmerman 03/
/92 YE NO YES NO YES NO YES NO YES NO
[SEND TO DCS
] SEND TO PDR ]
YES NO YES NO