ML20153B740
| ML20153B740 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 05/31/1988 |
| From: | CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | |
| Shared Package | |
| ML20153B723 | List: |
| References | |
| B12902, NUDOCS 8805060070 | |
| Download: ML20153B740 (11) | |
Text
_ - _ _ _ .
{ Docket No. 50-213 812902 Attachment 1 Haddam Neck Plant Assessment of Reverse Direction Testing of Containment Isolation Valves May 1988 8805060070 880502 PDR P
ADOCK 05000213 DCD
Attachment 1 B12902/Page 1 Assessment of Reverse Direction Testina of Containment Isolation Valves at the tijddam Neck Plant A two-cycle Appendix 10CFR50, schedular Jexemption from compliance at the Haddam Neck LJ iswith certain in currently provisions effect. g CYAPC0 is continuing to review the remaining Appendix J issues within the bounds of this schedular exemption, and will provide the results of this review to the NRC Staff in a future submittal. This letter does not resolve ,
any Appendix 50-245/87-18.gissues other than Exemptions those discussed to permit in Inspection reverse direction testingReport No.
are not being requested at this time. CYAPCO is continuing to review reverse direction testing of the valves discussed below, and will provide the results of these reviews in a future submittal, unless a permanent exemption allowing reverse direction testing of the particular valve has already been issued.
In response to the NRC Region I inspection discussed in Reference (2),
CYAPC0 reviewed all Haddam Neck Plant local leak rate tests (LLRTs) to identify valves that are reverse direction tested. Reverse direction tested valves were divided into two groups: 1) valves inside containment, and 2) valves outside containment. It was concluded that omission of packings and seals on containment isolation valves (CIVs) inside containment due to reverse direction testing is not an omission of testing of a containment boundary. This is because packing or seal leakage would only permit leakage fro;a one region of containment to another. This left the following reverse direction tested CIVs outside containment requiring further evaluation to address the concerns stated in Reference (2):
Test Procedure Penetration Valve lyn SUR 5.7-23 P-4 WG TV-1845 Globe-control SUR 5.7-44 P-62 SA V-413 Wedge-gate SUR 5.7-53 P 80 RH MOV-31 Wedge gate SUR 5.7-55 P-63 CC-V-884 Diaphragm SUR 5.7-59 P-78 DH A0V 554 Globe control SUR 5.7-59 P-14 DH-TV 1843 Globe-control SUR 5.7-104 P 33 PU V-242 Wedge-gate Discu;sion Brief discussions of these valves with respect to Reference (2)'s concerns are presented below. Details of the review of these valves are provided in Attachment IA.
(1) D. M. Crutchfield letter to E. J. Mroczka, "Exemption from certain Requirements of 10CFR Part 50, Appendix J," dated September 29, 1987.
(2) W. V. Johnston letter to E. J. Mroczka, "Inspection No. 50-245/87-18,"
dated September 23, 1987.
Attachment 1 B129,02/Page 2
- 1. CC-V-884 The LLRT for this valve checks the leak tightness of all potential containment isolation boundaries. This is achieved by a reverse
! direction water leakage test with a separate step which opens the valve and expcses all body joints to 70 psig water pressure.
- 2. DH-TV-1843 The direction of installation of this valve permits stem packing and all body joints to be included in its reverse direction LLRT.
Therefore, none of the potential containment isolation boundaries in this valve are omitted by presently utilized reverse direction test procedures.
- 3. DH-A0V-554 (also called DH-TV-554)
The direction of installation of this valve results in the inclusion of all body joints and stem packing in this valve's reverse direction LLRT. The containment side of this valve is also exposed to integrated leak rate test (ILRT) pressurization. Therefore, this valve is not subject to Reference (2)'s concern.
- 4. WG-TV-1845 This valve has a flanged mounting joint, stem packing, and body-to-bonnet joint on its containment side. Since this valve is reverse direction tested, these joints are not Appendix J. Type C leakage checked. However, these potential containment isolation boundaries are subjected to ILRT pressurization. These boundaries also demonstrate their leak tightness on a continuous basis during power generating operations by retaining pressurizer relief tank nitrogen bla.aket pressure.
- 5. RH MOV-31 This reverse direction tested valve has a stem packing and body-to-bonnet joint that are not checked by LLRT pressurization.
However, packings and seals on the containment side of RH MOV-31 can be exposed to ILRT pressure by opening a capped line. This ILRT direct pressurization combined with reverse direction LLRTs assures that all potential containment boundaries in RH H0V-31 are periodically leakage checked.
Since this valve is a wedge gate valve with disc / seat interfaces on both of its sides, it is possible that its packing and body joint may never be pressurized by a design basis accident (DBA). A permanent exemption permitting reverse direction testing of this valve was issued in Reference (1).
- 6. PU-V-242 If the inboard seat of this valve's split wedge disc does not seat, it is possible that a body to-bonnet joint and a stem packing may be exposed to DBA pressurization. These boundaries are not necessarily l
Attachment 1 B12902/Page 3 checked by the presently utilized reverse direction LLRT. CYAPC0 proposes to include this valve's containment side in the ILRT pressurization boundary by opening valve PU-V-240.
- 7. SA-V-413 This valve is opened and pressurized to 100 psig with air during refueling outages. The leak tightness of all body joints and packing are functionally demonstrated at this time. CYAPC0 proposes to soap bubble check all joints and the packing each refueling outage. These checks plus reverse direction testing would address Reference (1)'s concerns. The NRC Staff acknowledged and accepted procedural revisions made by CYAPCO to justify reverse direction testing of this valve in Reference (1).
Conclusions o Valves CC-V-884, DH-TV-1843, and DH-A0V-554 are clearly not subject to Reference (1)'s concern, since the leak tightness of all potential containment isolation boundaries is checked during their LLRTs.
o Valves WG-TV-1845, RH MOV-31, PU-V-242, and SA-V-413 have pressure boundaries that are omitted by reverse direction LLRTs. However, the leak tightness of these boundaries is or can be demonstrated on other bases (e.g.,ILRT).
)
~
l Docket No. 50 213 i 812902 -
\
l Attachment IA Haddam Neck Plant Detailed Assessment of Reverse Direction Testing of Containment Isolation Valves i
i 1
i l
l May 1988
1 Attachment IA
' B12902/Page 1 I
l
- 1. CC-V-884 '
This valve is a manual diaphragm valve socket welded into position I (both ends). Pertinent drawings are listed below.
16103-26005, Sheet 1 Rev. 28 (P&lD l 16103-26008, Sheet 3, Rev. 8 P&lD 16103/26008, Sheet 4, Rev 5 P&lD 16103 26008, Sheet 5 Rev. 6 P&ID 16103-29110, Sheet 1, Rev. 1 ValveAssembly) 16102-20310, Sheet 61, Rev. 1 (Test Diagram) o Normal position is closed (per NOP 2.8-1 and NOP 2.13-5; also shown as "locked closed" on P&lD).
o Outboard side of valve (i.e., the side away from containment) is normally at 70 psig (component cooling system pressure).
o Inboard side of valve (i.e., the side facing containment) is normally water covered. It is isolated from containment pressure by valves CC CV 886 and CC-Y-885. This line feeds the neutron shield tank which is vented to containment through the neutron shield surge tank.
o The two cycle schedular exemption implies that modifications will be made to permit Appendix J compliance concerning this valve or an exemption will be granted, o The valve is presently reverse direction tested with water at 70 psig, o The reverse LLRT does not include a portion of this valve's body-to-bonnet joint. This gasketed joint can act as a containment boundary during a DBA.
o The LLRT procedure does check the leak tightness of the entire body-to-bonnet joint. This is accomplished by a separate step within the procedure which opens the valve and exposes its pressure retaining body joints to 70 psig component cooling water.
o An ILRT does not expose this valve to DBA pressure because of valve CC-CV-886 inside containment.
- 2. DH-TV-1843 This valve is a diaphragm-actuated, double seated globe valve with socket weld ends. It is designed and installed for air-to open, flow-to close use. Pertinent drawings and figures are listed below.
16103-26031, Sheet 2, Rev. 2 (PalD) 16103-26007, Sheet 1 Rev. 9 (P&lD) 16103 20310, Sheet 22, Rev. 1 (Test Diagram) 16103-29144, Sheet 62, Rev. I (Valve Data) 16103-29144, Sheet 121, Rev. 1 (Valve Data)
Masonellan Catalog Figure #37-10163 (Provided in Figure 3)
.. Attachment 1A B12902/Page 2 o Normal position is closed per P&lDs. Per NOP 2.13 5, DH V 320 must be closed if this valve is not functional.
o The outboard side of this valve is routed to the primary drains tank, but is isolated from this tank by valve DH-TV-1844 which is normallyclosed(perPalD).
o The inboard side of this valve is routed to the vapor seal head tank. The head tank and the va closed inside containment (i.e., por the seal headlines tankare essentially is not vented; water from this tank is isolated from reactor coolant and containment atmosphere at the #3 reactor coolant pump shaft seal).
o The valve is presently reverse direction tested with nitrogen. A 47 psig to 42 psig pressure drop test is used. This LLRT checks DH-TV-1844 DH-TV-1843, and DH-TV-554 (reversepres(direct pressurization),
surization) simultaneously, o Since this valve has a balanced port design (it is really a double plug flow control valve), the direction of LLRT pressurization should have no effect on disc / seat leak tightness, o The body of this valve has a flow arrow. When installed with the flow as shown in test diagram 16103 20310, Sheet 22, reverse direction test pressurization will include this valve's stem packing and body joints. Original procurement specifications are consistent with this direction of installation. Therefore, this valve is not subject to Reference (1)'s reverse direction test concerns with its present orientation.
- 3. DH A0V-554 This valve is a diaphragm actuated, single seated globe valve with socket weld ends. It is designed and installed for air-to o flow to open use. Pertinent drawings and figures are listed below. pen, 16103-26301, Sheet 2, Rev. 2 (P&lD) 16103-26007, Sheet 3, Rev. 2 (P&lD) 16103-20310. Sheet 78, Rev. 1 (Test Diagram) 16103-29144, Sheet 87, 7/15/65 Revision (Valve Data)
Masonellan Catalog Figure #38-20521 (Provided as Figure 4) o Normal position is closed (per P&lD).
o The outboard side of this valve is routed to the primary drains tank through normally closed valve DH-TV-1844 (per P&lD).
o The inboard side of this valve is exposed to pressurizer relief tank (PRT) nitrogen pressure of 3 psig.
o The two cycle schedular exemption requires the issuance of a permanent exemption from Appendix J or modifications to permit direct pressure testing must be completed.
Attachment IA B12902/Page 3 o This valve is presently reverse direction tested with nitrogen. A 47 psig to 42 psig pressure drop is used. The LLRT for this valve includes DH TV-1844 and DH TV-1843.
o The air to open, flow to open orientation indicates that a body-to-bonnet joint and a stem packing are on the outboard (away from containment) side of this valve. These pressure boundaries are included in the reverse direction LLRT. Therefore, this valve is not subject to the concerns raised by Reference (1).
o Reverse direction testing tends to force the subject valve's disc into its seat. DBA pressure would tend to push the valve's disc out of its seat.
o The containment side of this valve is continuously exposed to the PRT nitrogen pressure. Leakage on this side of the valve would depressurize the PRT which would trigger an alarm via pressure transmitter #406. Therefore, the leak tightness of this side of the valve is demonstrated on a continuous basis, o Since the PRT is vented to containment during an ILRT, the inboard side of this valve is also leakage checked daring the ILRT. This is a direct pressure Type A test.
- 4. WG-TV-1845 This valve is a diaphragm-actuated, single seated globe valve with bolted, gasketed ends. It is designed and installed for air-to open, flow-to-close use. Pertinent drawings and figures are listed below.
16103-26007, Sheet 2, Rev. 7 (P&lD) 16103-26007, Sheet 3, Rev. 2 (P&lD) 16103-20310, Sheet 6, Rev I (Test Diagram) 16103 29144, Sheet 85, Rev.1 (Valve Data)
Hasonellan Catalog Figure #38 20521 (Provided as Figure 5) o Normal position is open (closed if it is not operable, per NOP 2.13-5).
o The outboard side of this valve is normally isolated from the primary vent header and the sampling system by normally closed valves WG A0V 558 and WG V-984A (reference NOP 2.5-1 and test diagram 16103 20310, Sheet 6, respectively).
o The inboard side of this valve is normally exposed to PRT nitrogen blanket pressure (3 psig).
o This valve is presently reverse direction tested with nitrogen. A
- 47 psig to 42 psig pressure drop test is used.
o This air-to-open, flow to-close orientation indicates that a body-to bonnet joint and a stem packing are on the containment l side of this gasketed valvejoint flange (relative to its disc also exists / seat on this interface).
inboard side of A
l l
Attachment IA
.B12902/Page 4 WG-TV-1845. These potential containment isolation boundaries are not included in the reverse directinn LLRT.
o Reverse direction testing tends to push the valve disc out of its seat. DBA pressure tends to push the valve disc into its seat.
o Since the containment side of this valve is normally exposed to PRT pressure, the potential containment boundaries missed by LLRT continuously demonstrate their leak tightness by retaining this pressure. Loss of PRT pressure triggers an alarm via pressure transmitter #406.
o Since the PRT is vented to containment during an ILRT, the potential containment boundaries missed by the LLRT are also leakage checked by the ILRT. This type of leakage check is more appropriate for the gasketed mechanical piping joint on the inboard side of this valve.
- 5. RH MOV-31 This valve is a motor-operated, solid wedge gate valve with butt weld ends. Pertinent drawings are listed below.
16103-26056, Sheet 1 Rev. 10 (P&lD) 16103-26028, Sheet 1. Rev. 10 (P&ID) 16103-29072, Sheet 22, Rev. 0 (Valve Assembly) 16103 20310, Sheet 80, Rev. 1 (Test Diagram)
Stone & Webster Purchase Order #L.0. 123 6 o Normal position during power operation is closed. (Note: Opening of this valve results in containment spray.)
o The outboard side of this valve is normally exposed to 80 psig fire water pressure.
o The inboard side of this valve is protected from exposure to containment atmosphere by check valve RH CV-35. This side of the valve is normally depressurized, o A permanent exemption permitting reverse direction testing of this valve has been issued, o This valve is presently reverse direction tested with water at 80 psig, o The ILRT procedure requires the blanking and venting of the outboard side of this valve to establish proper differential pressure at penetration P 80. However, the inboard side of RH-MOV-31 will not be exposed to ILRT pressure if check valve RH CV-35 is leak tight. A capped branch line between the penetration and check valve RH-CV-35 can be opened to expose RH MOV-31 to direct pressurization during an ILRT.
o Since this valve is a wedge gate valve with inboard and outboard disc / seat interfaces, it is po:sible that the stem packing and
Attachment IA B12902/Page 5 gasketed body-to b9nnet joint may never be pressurized during an ILRT or a DBA. If the inboard seat is not leak tight, these other valve pressure boundaries may become potential containment isolation boundaries, o This valve is in the radioactive pipe gallery. This location makes soap bubble checks and modifications to permit direct pressure LLRTs impractical from a personnel exposure standpoint.
- 6. PU-V-242 This valve is a manual, split wedge, gate valve with butt weld ends.
Pertinent drawings are listed below.
16103-26018, Sheet 1, Rev. 8 (P&lD) 16103-26018, Sheet 2, Rev. 10 (P&lD) 16103-29355, Sheet 12, Rev. 0 (Valve Assembly) 16103 20310, Sheet 47, Rev. 1 (Test Diagram) o This valve is normally closed during plant operation (per NOP 2.13-5).
o The inboard side is routed to the refueling cavity. Since the cavity is drained and isolated during plant power operations, this valve is not exposed to containment atmosphere or any inboard system pressure during such operations, o The outboard side of the valve is isolated from the volume control tank and purification section of the chemical and volume control system (CVCS) during power generating operations, o When the refueling cavity is filled and aligned to the CVCS, there is approximately 30 feet of water over PU Y-242. A hydraulic head of 92.4 feet would be required to duplicate DBA pressure (40psig).
o The two cycle schedular exemption requires the issuance of an exemption or modifications to permit full Appendix J compliance.
o The valve is presently reverse direction tested with nitrogen. A pressure drop test from 47 psig to 42 psig is performed.
o The split wedge design lends itsel f to better seating with increased closure torque.
o It is possible that the separate wedges will permit the valve to seat tightly on both of its seats. In this case, the body-to bonnet joint and stem packing will not be exposed to post accident pressure or reverse direction test pressure. This would make the direction of pressurization meaningless as far as packings and seals are concerned, o The stem packing and body to bonnet joint may be exposed to pressure if the inboard seat leaks and if valve PU V 240 is left I
. Attachment IA
,812902/Page 6 open during an ILRT. CYAPC0 proposes to open valv6 ' (-240 during ILRTs as a means of satisfying Reference (1)'s ' verse direction testing concerns.
- 7. SA-V-413 This valve is a manual, solid wedge gate valve with female threaded ends. Pertinent drawings are listed below.
16103 26051, Sheet 1. Rev. 16 (P&ID) 16103-29163, Sheet 5, Rev.1 (Valve Assembly) 16103-20310, Sheet 60, Rev. 1 (Test Otagram) o Normal position is closed (per NOP 2.13 5). This valve has a closure torque requirement of 15 ft-lbs, o The outboard side of this valve is routed to the service air system. However, this valve is isolated from the service air system by other normally closed valves between it and the service air receiver tank (TK-28-1A). If the service Air piping is leak tight, it is possible that a 100 psig gas charge may be trapped in the lines upstream of this valve. Such a seal could help to prevent leakage during a DBA.
o The inboard side of this valve is routed to m.iny air hose connection points and breathing air stations within containment.
It is isolated from containment atmosphere during power generating operations by two check valves and dead ended lines at the air stations and hose connection points.
o The NRC has accepted the reverse direction testing of this valve.
The LLRT for this valve is a pressure decay test (47 psig to 42 psig) using service air.
o This valve is not likely to be exposed to containment pressure during an ILRT, even though the service air system is vented to containment atmosphere by opening SA Y 430 during an ILRT. This is because check valves SA-CV 417 and SA-CV-415 will isolate SA-Y-413 if they are leak tight-o Since this valve is a wedge gate valve with inboard and outboard disc / seat interfaces, it is possible that the valve's threaded body to-bonnet joint and its stem packing may never be pressurized during an LLRT or a DBA. However, if the inboard seat is not leak tight, these other valve pressure retaining boundaries may become potential containment isolation boundaries.
o This valve is opened and pressurized to 100 psig during refueling outages. The leak tightness of the body-to bonnet joint and the stem packing is functionally demonstrated at this time. Since the -
valve is in an accessible section of the Primary Auxiliary Building, CYAPC0 proposes to roap bubble check all of its joints (including its threaded ends) during every outage.