ML20097E966
| ML20097E966 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 06/05/1992 |
| From: | William Cahill, Woodlan D TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20097E968 | List: |
| References | |
| TXX-92260, NUDOCS 9206150118 | |
| Download: ML20097E966 (7) | |
Text
_ _ _ _ _ _ _ _ _-__ ___ _ ____
U"O Log # TXX-922f,0
""" =
rile # 10014 j
916 clo r
r TUELECTRIC June 5, 1992 wim.m J. c.hnt, Jr, Over M frnidret U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE FEAK STEAM ELECir<!C STATION (CPSES)
DOCKET N05. 50-445 AND 50-446 PROPOSED CHAf1GES TO THE NRC flRST DRAFT ON COMANCHE PEAL UNITS 1 A 2 COMBINED TECHNICAL SPECIFICATIONS FOR STATION SERVICE WATER SYSTEM 3/4.7.7 REF:
1)
NRC letter from Mel B. Fields to W. J. Cahill, 1r.
dated March 24, 1992.
Gentlemen:
Reference 1 provided CPSES with a copy of the flRC's first draft Technical Specifications.
TV Electric reviewed this document for proposed changes in the Station Service Water System (Technical Specification 3/4.7.4 and its BASES).
Subsequent meetings were held with the NRC to discuss this change, As part of the ongoing Technical Specification development efforts, and as discussed in an April 23 and 24, 1992, meeting with the flRC, the attached changes to the NRC's first draft Technical Specifications are hereby provided. The attached pages are iritended to supersede pages 3/4 7-14, 3/4 7-15 ane B 3/4 7-4 of the NRC first draft (Reference 1).
Sincerely, William J. Cahill, Jr.
By:
M D. R. Woodlan Docket Licensing Mananer MCP/ds c - Mr. R. D. Martin, Region IV Resident Inspectors, C0SES (2)
Mr. T.
A.
Bergman, NRR Hr. B, E. Holian, NRR
.. n n n m a 9206150118 920605 PDR ADOCK 05000445 P
PDR 400 N. Ouve street L.B. 81 Danas. Texas 75201 O
ip
i '
ATTACHMENT 1 JUSTIFICATION FOR PROPOSED STATION SERVICE WATER SYSTEM TECHNICAL SPECIFICATION
l
.1
- Q' Attachment _1.to.TXX 92260-Page L of 5-Descrintien of Technical SDecification Chanaes and_ Justification 1.
BACKGROUND The-existing CPSES Technical _ Specification 3/4.7.4 (Ref. 1), is
. consistent with_the Westinghouse Standard Technical Specifications
.r ovided by the NRC to TV Electric in 1987 (Ref, 2),
Technical Specification 6.8 covers the implementation of the Technical
- Rt suirements Manualg(Ref. 3), which includes Technical-Requirement 3.2, Station Service Water _ System Operability Criteria (Ref. 4).
The TRM 3.2 requires a: Unit 2 service water pump.to be available to support Unit 1 operation whenever Unit'I is in Modes 1, 2, 3 and 4, if this condition is:not satisfied,-a Unit 2 pump must be restored to available-status within 7 days or Unit 1 must be shut down, if only one Unit 1 service water: pump is.0PERABLE and neither Unit 2 pump is available, immediate-action to restore at least one additional pump is required,- Verification of Unit 2 pump availability includes an energized bus- (once per day), cross connect availability (once per day),
cross connect valve testing (quarterly) _and monthly pump' runs of at
.=
U least 15 minutes. This technical requirement was implemented to improve service water reliability based on generic probabilistic assessment of
. plants with two full capacity service water pumps and Information Notice 4
No. 86-11 (See Ref. 5 and 6),
Generic _ Letter 91-13.(Ref. 7) proposed technical specification changes 1.
to ennance the availability-of the essential service water system.
l TV Electric's response (Ref. 8) committed ti propose a revision-to the
-CPSES Technical-Specifications and.their bases to address _ the concerns s
of Generic Letter 91 13. The proposed changes are expected to be incorporated into the CPSES Unit 1-and 2 combined Technical l'
Specifications _(Ref. 9).
.The relevant system configuration is shown on the-attached sketch
=(Figure 1).
E CPSES_has.two 100 percent capacity Station-Service Water pumps per Unit.
l-These:four pumps have crosstie capability such that any pump may supply any other pump's cooling loads.
The_ unit crosstie pipino is ASME Class 3 and contains five manual gear operated _ butterfly valves (XSW-0006, XSW-0007, XSW-0008, XSW-0028 and XSW-0029),
Each train's
~
crosstie isulation valve is maintained ~in the normally closed position.
The Unit 1/ Unit 2-crosstie valve (XSW-0006) is locked closed and will normally be maintained in the locked closed _ position during two unit
- operation in' order to satisfy GDC-5 (Ref. 10, SSER-22; Section-9,2.1) except:'or flushing in accordance with GL 89-13 (Ref. 11).
To establish a crosstie between the Units, three of these valves (including
.XWS-0006) must be opened ~(See Figure 1).
The cross connect valves are manual, gear operated, butterfly valves with. rubber seats and are not prone to binding due to differential pressure, galvanic corrosion or hydraulic blocking above the disc.
to TXX-92260 Page 2.of 5 Although testing is not required by ASME Section XI, quarterly f ull stroke testing of these valves is censistent with Generic letter 91-13 and the ASME Section XI IWV-3400 requirement for Category A and B valves and thus provides reasonable assurance that the valves will be functional.
The basis for this Technical Specification change is the loss of service water event.
It is postulated to occur in a Unit operating in MODES 1,2,3 or 4.
If the unit is operating in an LCO Action, an additional f ailure (i.e.
single f ailure) is not assumed to occur.
An analysis of this event will be performed and documented as appropriate in Licensing Basis and Design Basis Documents.
.i
'PTION OF TECHNICAL SPECIFICATION CHAllGE AND JUSTIFICATION oposed Technical Specification (TXX 92120 commitment) is tent with the Generic Letter 91-13 draft specification except for:
The proposal splits the requirements into two speci fications so that a shutdown unit can satisfy the LCO without entering the action statement.
Proposed T/S 3/4.7.4 is to be divided into 3/4.7.4.1 for both Units in MODES 1,2,3, or 4 and 3/4.7.4.2 for only one Unit in MODES 1, 2, 3, or 4 and the other unit in MODES 5,6 or defueled.
The proposed draft Technical Specifications contain all the requirements of NRC first draft Technical Specifications 3/4.7.4 (Reference 9) in a split Limiting Condition of Operation (LCO) without requiring either unit to enter an ACTION Statement.
2)
The addition of the "defueled" Mode to cover standard refueling practices and the plant status prior to Unit 2 fuel load, tiRC first draft Technical Specifications 3/4.7.4 (Reference 9) and Generic Letter 91-13 (Reference 7) did not cover one Unit in MODES 1,2,3, or 4 and one Unit in MODE defueled, which is required upon receipt of the CPSES Unit 2 Operating License.
3)
The seven day A0T for the pump in the shutdown unit to allow for maintenance of pumps and cross-ties during refueling / maintenance outages.
TU Electric considers 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowable outage time t A0T) as provided by NRC first draft tReference 9) and Generic letter 91-13 (Reference 7) is unnecessarily restrictive and proposes a 7 day A0T.
_ to TXX-92260 Page 3 of 5 A PRA calculation was perf ormed to determine the change in total core damage f requency due t o the A01 variation f rom 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days.
The results show that the impact of change in A0T ftom 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days on the calculated core damage frequency is less than 0.1%.
The equipment unavailability due to increase in A0T is insignificant and, therefore, it has relatively no impact on the total core damage frequency.
The seven day A0T for the cross-connect valves and the supporting purrp f rom a shutdown unit is consistent with the CPSES TPM 1.3 and Byron Unit 1 and Unit 2 Technical Specifications (HilREG-1113.
AM-24, Section 3/4.7.4).
The requirement is also consistent with the River Bend Technical Specifications (NUREG-1172 Nov. 1985. Section 3/4.7.1).
River E
Bend has four, 100% pumps suppling two redundant essential service water loops.
The A0T for one pump OPERABLE is 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> which is consistent with Standard Technical Specifications.
The A0T for two pumps OPEPABLE is seven (7) days.
The seven day A0T for the " third pump" is also more resttictive than that for plarits with three pumps with standard technical specifications which allow unlimited A0T for the third pump.
(e.g. Beaver Valley 2 St. Lucie Unit 2, Waterford 3) or plants with no third pump (e.g. Palo Verde).
4)
Miscelleneous Changet a)
Deleted 2nd sentence in LCO 3.7.4 'NRC first draft, Reference 9). 'In addition, the cross-connect valves XSW-0006, XSW-0007, XSW-0008, XSW-0028 and x5W-0029 shall be capable of being opened [from the main control room] to provide a flow path between the two Units" This portion of the LCO is not applicable to the CPSES design (See item 1 above for additional information),
b)
Cross-connect valve and pump OPERABLE (BASES 3/4 7.4 ):
The clarification below is provided in the BASES 3/4 7.4 for the cross-connect valve and SSW pump operability.
A cross-connect valve is OPERABLE if it can be cycled or is locked open however, at least one cross-connect valve between units is required to be maintained closed in accordance with GDC-5 unless required due to total loss of SSW pumps for cither unit.
The OPERABLE pump is manually realianed and flow belanced to provide tooling to essential heat loads
_ _ _ _ _ _ _ _. to TXX-92260 Page 4 of 5
- 11. REFERENCES 1.
NUREG-1399, Technical Specifications, Comanche Peak Steam Electric Station, Unit 1. Docket No. 50-445, April 1990, 2.
Technical Specifications for Comanche Peak Steam Electric Station (CPSES) Unit 1, Docket No. 50-445, dated August 14, 1987 from Christopher 1. Grimes (USNRC) to William G. Counsil (TU Electric).
3.
TXX-89038. Technical Requirements Manual (TRM), Comanche Peak Steam Electric Station, Docket No. 50-445, from William J. Cahill, Jr. (TV Electric) to USNRC, dated January 24, 1989.
4.
TXX-88848, Service Water System Reliatility. CPSES, Docket Nos.
50-445 and 50-446, from William G. Counsil to USNRC, dated December 16, 1988.
5.
Ci rcul ar 78-13. "Inoperability of Service Water Pumps,"
July 10, 1978.
6.
IE Information Notice No. 86-11. " Inadequate Service Water Protection Against Core Melt Frequency," February 25, 1986.
7, Generic Letter 91-13, " Request for Information Related to the Resolution of Generic Issue 130, Essential Service Water System Failures at Multi-Unit Sites, Pursuant to 10 CFR 50.54( f )," dated September 19, 1991, 8.
TXX-92120, Request for Information - Essential (Station) Service Water Systein, NRC Generic Letter 91-13. Docket Nos. 50-445 and
~
50-446, from William J, Cahill, Jr. to USNRC dated March 16, 1992, 9.
NRC Letter f rom Mel B. Fields to William J. Cahill, Jr. dated March 24, 1992 regarding, " Comanche Peak Steam Electric Station Units 1 and 2 Combined Technical Specifications (TAC No.
M81963)"
10.
NUREG-0797, Safety Evaluation Report Related to the Operation of Conanche Peak Steam Electric Station, Units 1 and 2, through Supplement No. 24, April, 1990.
11.
Generit Letter 89-13, " Service Water Problems Affecting Safety Related EqJiDment" dated July 18. 1989, and Supploment 1. dated April 4,
1990.
-e?
E C e o wW
~a o
n CPSES. SERVICE WATER SYSTEMS-G UNIT 1 UNIT 2 5
k; O
O O
O E
~
1 1
a a
5 5
(h (h
~~ k 5
5 b
x5w-oos h,
hf f
,/-
/--
/-
/
X5w-028 M5w-029 i ~'
~
15W-373 15 w-3 74
~ 25W-374 25w-373 r
A 18 A
1A A
2A
'^
2B
(.
(
(
(
i SERVICE WATER SUCTION BAY
'