ML20056F050
| ML20056F050 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 08/19/1993 |
| From: | Simpkin T COMMONWEALTH EDISON CO. |
| To: | Murley T Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9308250477 | |
| Download: ML20056F050 (12) | |
Text
. -
Ccmm:nwscith Edis:n
~r*
1400 Opus Place Downers Grove, Illinois 60515 August 19,1993 Dr. Thomas E. Murley, Director Ofc. of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
Zion Nuclear Station Units 1 and 2 Second Interval Inservice Inspection Program Relief Requests NRC Docket Nos. 50-295 and 50-304
Dear Dr. Murley:
The purpose of this letter is to forward the following ISI Program Relief Requests:
1.
Hydro Relief Requests #11,12,13,14, and 15 2..
Technical Approach and Position #11 Hydro relief requests #11 and 12 propose alternate examinations for buried lines.
Hydro relief #13 addressed the examination requirements for the Auxi%ry Feedwater l
Pump Turbine Oil Coolers, while Relief #14 seeks alternate testing in neu of the Code-l required system hydrostatic test for the Auxiliary Feedwater piping associated with the i
turbine-driven pump. Hydro Relief #15 requests relief from the hydrostatic test of the l
1/2 " Isolation Valve Seal Water Piping.
i j
Technical approach and Position #11 relates to the hydrostatic test boundaries l
with respect to tubing downstream ofinstrument root causes.
Due to potential impact these relief requests will have on the upcoming Dual Unit Outage, approval is requested by December 31,1993.
c l
l l
.J500aS 9308250477 930s19 m
- y/
l PDR ADOCK 05000295 f$
. )-
g h;
G PDR 1
k \\nla\\1tr-nrcz.wpf/15
1 l
Dr. Murley August 19,1993 j
If there stre any questions or comments regarding this matter, please direct them j
to this office.
1 Sincerely, i
-wW.
/
T.W. Simpkin Nuclear Licensing Administrator Attachments cc:
C. Shiraki - NRR B. Clayton - RIII J.D. Smith - Senior Resident Inspector - Zion f
I kt\\nla\\ltr-ntcz.wpf/16 I
f ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL Hydro Relief Request #11 (Page 1 of 2)
COMPONENT IDENTIFICATION Code Class:
3
References:
IWA-5244 Examination Category:
D-B ltem Number:
D2.10
==
Description:==
Pressure Testing of 48" Service Water Pump Discharge Buried Lines DETAILED DESCRIPTION P_&lH: M-32, Sheets 1 & 4 Service Water l
The buried piping includes two sections of 48" piping located between the crib house and auxiliary building: Line OSWO13-48"X1-N (@E-5); buried portion is approximately between branch lines OSWO43-14"X1-N and OSW141-4"X1-N.
Line OSWO14-48"X1-N (@E-3); buried portion is approximately between branch lines OSWO49-14"X1-N and OSW140-4"X1-N.
Both sections of buried piping include a 100' horizontal run, connecting to a 40' vertica! run, which then connects to a 120' horizontal run. (Piping run lengths are approximate).
These piping sections are considered nonredundant. These piping sections are also considered isolatable as valving is available on either side of the buried sections.
CODE REQUIREMENT IWA-5244(a), Buried Components, states: "In nonredundant systems where the buried components are isolatable by means of valves, the visual examination.VT-2 shall consist of a leakage test that determines the rate of pressure loss. Alternatively, the test may determine the change in flow between the ends of the buried components.
The acceptable rate of pressure loss or flow shall be established by the Owner."
BASIS FOR REllEE Relief is requested on the basis that the proposed alternatives would provide an acceptable level of quality and safety.
The testing options available per ASME Section XI, pressure loss and change in flow are not practical to perform.
COE-275 052 ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL Hydro Relief Request #11 (Page 2 of 2)
BASIS FOR RELIEF (cont'd)
Previously, a pressure loss test was attempted. Due to extensive boundary valve leakage, the test failed. The majority of these boundary valves are butterfly type which may not exhibit the necessary isolation characteristics to successfully complete a pressure loss test. In summary, the pressure loss testing methods available for the subject piping will not provide conclusive evidence of the pressure retaining capability of this buried piping.
I investigations into change in flow testing for the subject piping indicate that this methodology will also be impractical. Permanent service water flow instrumentation is not available to accomplish a change in flow test.
No downstream flow instrumentation on the 48" lines is currently in place. Similarly, temporary flow instrumentation wili not be feasible for this test due to system configuration constraints. (Branch piping ties in immediately after the 48" lines become exposed in the auxiliary building.) This configuration will not allow an accurate downstream flow measurement to be taken.
PROPOSED ALTERNATE EXAMINATIONS As an alternative examination, Zion Station will perform a visual examination of the internal surfaces of the subject piping, to the extent practical.
The upcoming dual unit outage modifications to the Service Water System will allow individual and/or remote " crawler" entry into the 48" buried piping for visual inspections of the pipe internal surfaces.
At a minimum, Zion Station will perform the visual examination on a portion of the piping internal wall surfaces in each physical section (four horizontal sections and two vertical sections) that can be performed safely. Zion Station will attempt to obtain a visual sampling of the pipe wall in each of these sections in order to verify its' pressure retaining capability.
Documentation will be developed detailing the visual examination, including a specific set of acceptance criteria. In general, the acceptance criteria would not allow defects which indicate through wall leakage. Allowances will be made in the examination acceptance criteria to take into account service related wear and internal fixed debris normally expected in Service Water Systems.
Successful completion of this alternative examination willverify the pressure retaining capability of this piping, and is therefore deemed an acceptable alternative.
COE-275 052 2-
i
~
ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL i
Hydro Relief Request #12 i
(Page 1 of 2) i COMPONENT IDENTIFICATION 1
l Code Class:
3 j
References:
IWA-5244 Examination Category:
D-B l
Item Number:
D2.10 j
==
Description:==
Pressure Testing of 1" Supply and Discharge Buried Lines to Reactor Vessel Support Pads l
DETAILED DESCRIPTION P&lD: M-93 (Unit 1) - Penetration and Support Cooling l
The buried piping is shown entering and exiting four reactor vessel support pads on l
the P&lD. Each pad is serviced by two inlet lines and two outlet lines. The line numbers of the buried piping are as follows:
i
)
Unit 1 1CC125-1"X1-N f
1CC186-1"X1-N 4
1CC126-1"X1-N I
1CC187-1"X1-N 1CC180-1"X1-N 1CC181-1"X1-N
.f 1CC123-1"X1-N 1CC188-1"X1-N I
I 1CC177-1"X1-N 1
1CC183-1"X1-N These buried piping runs are considered nonredundan1. These piping runs are also considered isolatable as valving exists on either side of the buried portions.
i COE-275-052 I
ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL i
Hydro Relief Request #12 (Page 2 of 2)
CODE REQUIREMENT IWA-5244(a), Buried Components, states: "In nonredundant systems where the buried components are isolatable by means of valves, the visual examination VT-2 shall consist of a leakage test that determines the rate of pressure loss. Alternatively, the test may determine the change in flow between the ends of the buried components.
The acceptable rate of pressure loss or flow shall be established by the Owner."
\\
BASIS FOR REllEE Relief is requested on the basis that the proposed alternatives would provide an acceptable level of quality and safety.
Investigations into performance of the testing options available per ASME Section XI indicate that pressure loss testing is not practical due to the location, size, and configuration of the subject piping.
PROPOSED ALTERNATE EXAMINATIONS l
A test which determines the change in flow between the ends of the buried piping will be attempted using ultrasonic flow meters. Due to the low flow rates expected and the inherent limitations of the flow measurements on small diameter piping, it is not known whether this test method will provide conclusive results.
As an alternative examination, in the event that flow change testing does not provide conclusive results, Zion Station will perform a visual VT-2 examination on the areas where this piping enters and exits the Reactor Vessel support pads. This examination will be performed when the subject piping is pressurized to the hydrostatic pressure l
required per IWD-5223.
l CoE-275-052
+
i l
ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL Hydro Relief Request #13 (Page 1 of 1) i COMPONENT IDENTIFICATION Code Class:
3 j
References:
IWD-5223(a)
Examination Category:
D-B ltem Number:
D2.10 l
==
Description:==
Pressure Testing of Turbine Driven Auxiliary Feedwater Pump Oil Cooler and Attached 1/2" Lines 1
l DETAILED DESCRIPTION Unit 1:
Auxiliary Feed Pump 1 A Turbine Oil Coolers and attached piping j
(M37, sheet 1).
Unit 2:
Auxiliary Feed Pump 2A Cooler and attached piping (M37.2).
a CODE REQUIREMENT I
IWD-5223(a), System Hydrostatic Test, states: "The system hydrostatic test pressure shall be at least 1.10 times the system pressure P,, for systems with Design Temperature of 200'F (93 C) or less, and at least 1.25 times the system pressure P, for systems with Design Temperature above 200 F (93 C). The system pressure P,, shall be the lowest pressure setting among the number of safety or relief valves provided for overpressure protection within the boundary of the system to be tested.
For systems (or portions of systems) not provided with safety or relief valves, the system design pressure P, shall be substituted for P,,."
BASIS FOR REllEF Relief is requested on the basis that compliance with the Code requirement would result in hardship or unusual difficulty without a compensating increase in the level of safety and quality.
The design of this portion of the Service Water System includes a relief valve set at 125 psig and a pressure control valve set at 75 psig, which was included to protect the subject cooler from overpressurization. Testing of the cooler, attached piping and the relief valve to IWD-5223 rules would require a test pressure of 132.5 psig, which would exceed the cooler design pressure of 120 psig.
PROPOSED ALTERNATE EXAMINATIONS As an alternative examination, Zion Station will perform a visual, VT-2 examination of the oil coolers and attached piping, up to and including the first available isolation valves. This examination will be performed when the subject piping is pressurized to normal system operating pressure.
COE-275-052 ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL i
Hydro Relief Request #14 (Page 1 of 2)
COMPONENT IDENTIFICATION Code Class:
3
References:
IWA-5244 Examination Category:
D-B ltem Number:
D2.10
==
Description:==
Pressure Testing of 6" Piping to Auxiliary Feedwater Pump 1 A and 2A Turbines DETAILED DESCRIPTION P&lD:
M-20 (Unit 1) and M-500 (Unit 2) - Main Steam Unit 1 - Piping between 1MOV-MS0011 and downstream check valve 1MS-0007; piping between 1MOV-MS0005 and downstream check valve 1MS0006. Unit 2 -
piping between 2MOV-MSOO11 and downstream check valve 2MS-0007; piping between 2MOV-MS0005 and downstream check valve 2MS0006.
CODE REQUIREMENT IWD-5223(a), System Hydrostatic Test, states: "The system hydrostatic test pressure shall be at least 1.10 times the system pressure P,, for systems with Design Temperature of 200*F (93 C) or less, and at least 1.25 times the system pressure P,, for systems with Design Temperature above 200 F (93*C). The system pressure P,, shall be the lowest pressure setting among the number of safety or relief valves provided for overpressure protection within the boundary of the system to be tested.
For systems (or portions of systems) not provided with safety or relief valves, the system design pressure P, shall be substituted for P,,."
1 BASIS FOR REllEF Relief is requested on the basis that the proposed alternatives would provide an j
acceptable level of quality and safety.
In order to test this piping per ASME Section XI, the check valves in these piping runs would require disassembly. These check valves are of split body design and plant maintenance experience is that significant risk of valve damage is possible during disassembly / reassembly activities.
In addition, no system connections are available to pressurize around the check valves in order to accomplish this test.
CoE-275-052 I
i ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL i
Hydro Relief Request #14 j
(Page 2 of 2) l
}
PROPOSED ALTERNATE EXAMINATIONS i
l 2
As an alternative test, this piping will be visually, VT-2 examined at nominal operating pressure during operational testing of the Auxiliary Feedwater Pump Turbine.
j l
I i
t
)
1 i
1
.g 1
1 6
b p
b 1
COE 275-052 7
ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL Hydro Relief Request #15 (Page 1 of 1)
COMPONENT IDENTIFICATION Code Class:
3
References:
IWD-5223(a)
Examination Category:
D-A, D-8, D-C item Number:
D1.ST
==
Description:==
Pressure Testing of 1/2" Isolation Valve Seal Water Piping DETAILED DESCRIPTION Piping between the following valves:
Unit 1: P&lD M-39 (zone 01);
Unit 2: P&lD M 512 (zone 01);
-11W0084 and 11WO153
-21 WOO 84 and 21WO153
-11WO198 and 11WO196
-21WO198 and 21WO196
-11 WOO 58 and 1tWO154
-21 WOO 58 and 21WO154
-11 WOO 59 and 11WO155
-21 WOO 59 and 21WO155
-1l WOO 60 and 11WO156
-21 WOO 60 and 21WO156
-1tWOO61 and 11WO157
-21 WOO 61 and 21WO157
-11WO186 and 1 AOV-DT91598 (M-87; D-5) -21WO186 and 2AOV-DT91598 (M-87; D-4)
CODE REQUIREMENT IWD-5223(a), System Hydrostatic Test, states: "The system hydrostatic test pressure shall be at least 1.10 tim the system pressure P, for systems with Design Temperature of 200 F (93'L) or less, and at least 1.25 times the system pressure P,, for systems with Design Temperature above 200 F (93 C). The system pressure P,, shall be the lowest pressure setting among the number of safety or relief valves provided for overpressure protection within the boundary of the system to be tested.
For systems (or portions of systems) not provided with safety or relief valves, the system design pressure P, shall be substituted for P,.."
BASIS FOR RELIEF Relief is requested on the basis that the proposed alternatives would provide an acceptable level of quality and safety.
Check valves isolate the affected piping from the remainder of the system piping of the same design. A Pipe Design Table change occurs (Table "B" or "E" [2485 psig]
or "C" [2500 psigl to Table "X-1" [150 psig]) at the manual isolation valves on the inlet side of the check valves. No test connections are provided between the check valves and the isolation valves making it impractical to test the affected piping to IWD-5223 requirements.
CoE-275-052 ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL PROPOSED ALTERNATE EXAMINATIONS As an alternative examination, Zion Station will perform a visual, VT-2 examination of the subject piping in conjunction with the isolation Valve Seal Water System Hydrostatic Test per IWD-5223(c). This test will be based on Pd = 150 psig, I
)
COE-275-052 9
l i
u ZION STATION UNITS 1 AND 2 SECOND TEN YEAR INTERVAL TECHNICAL APPROACH AND POSITION NUMBER #11 (Page 1 of 1)
COMPONENT IDENTIFICATION Code Class:
1, 2, and 3
References:
IWA-5210, IWA-5224 Examination Category:
Not Applicable item Number:
Not Applicable
==
Description:==
System Pressure Testing Beyond Instrument Root Valves CODE REQUIREMENTS IWA-5211, Test Description, states: "The pressure retaining components within each system boundary shall be subject to system pressure tests under which conditions visual examination VT-2 is performed in accordance with IWA-5240 to detect leakages. The required system pressure tests and examinations, as referenced in Table IWA-5210-1, may be conducted in conjunction with the following system test or operation: a system hydrostatic test conducted during a plant shutdown at a pressure above nominal operating pressure or system pressure' for which overpressure protection is provided."
lWA-5224(a), System Hydrostatic Test Boundary, states: "The boundary subject to test pressurization during a system hydrostatic test [lWA-5211(d)] shall be defined by the system boundary (or each portion of the boundary) within which the components have the same minimum required classification and are designed to the same primary pressure rating as governed by the system function and the internal fluid operating conditions, respectively."
POSITION Because system instrumentation is normally valved into the system process piping, the tubing between the root valves and respective instruments has been classified ISI Class 1, 2, or 3, as applicable, at Zion Station.
These lines and instruments are thus subject to System Pressure Testing per IWA-5000. In situations where a System Hydrostatic per IWA 5211(d)is applicable, the elevated pressures required may exceed the design rating of the included instrumentation.
It is Zion Station's position that in cases where the System Pressure Testing of IWA-5211 is determined to exceed the design rating of the system instruments, the affected instruments will be isolated during such pressure testing by closing the respective instrument root valves.
' Refer to NB-7410, NC-7410, and ND-7410 for determination of system pressure for which overpressure protection is provided.
COE 275-052