ML20059M549
| ML20059M549 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 08/17/1993 |
| From: | AFFILIATION NOT ASSIGNED |
| To: | |
| References | |
| CON-#493-14436 OLA-2-I-MFP-006, OLA-2-I-MFP-6, NUDOCS 9311190158 | |
| Download: ML20059M549 (28) | |
Text
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NCRDC0-93-TPhN0fBRev.00 l
DRAFT: July 29, 1993
'93 0D 28 P 6 :15 DCO-93-TP-N028 CHECK VALVE TEST NOT INCLUDED IN IST PLAN MANAGEMENT
SUMMARY
b l
On March 3, 1984, for Unit 1 and on July 25, 1985, for Unit 2, Technical Specification (TS) 3.0.4 was not met when initial entry into Mode 3 (Hot Standby) was made without edequate reverse flow testing of safety injection (SI) pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B.
On June 25, 1993, a Technical Review Group (TRG) determined that l
the SI pump discharge check valves should be included in the IST l
program plan and that STP P-1B was inadequate to verify their l
safety function for reverse flow seating in accordance with ASME Section XI inservice testing (IST) requirements.
Since SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B are l
required to be operable to meet the requirements of TS 3.5.2 entry into an operating mode is not permitted per TS 3.0.4.
ireliminary: The root causes of this event include deficiencies in the scope of the IST Program Plan review, miscommunication and personnel error (cognitive).
The SI pump discharge check valves were not identified as required to be periodically reverse flow tested during the development of the IST Program Plan or subsequent reviews of the IST Program Plan.
Iests performed on Unit 1 and Unit 2 SI discharge check valves verified reverse flow seating in accordance with ASME dection XI IST requirements.
SI pump discharge check valves will be added to the DCPP IST Program Plan.
All other check valves will be reviewed against the requirements for inclusion in the IST Program Plan.
On May 12, 1993 NCR DCO-93-TP-N028 was initiated in accordance with QAP 15.B, paragraph 2.1.8 per Manager Technical Services.
This draft dated July 29, 1993 contains the minutes of the TRG held on July 13, 1993 and July 16, 1993.
The TRG reviewed the draft LER i
and agreed that the LER would take the direction of a programmatic deficiency, personnel error, and a misunderstanding of design basis information.
A shortened version of the draft LER J-84-047-00 was submitted to the NRC on 7/26/93.
The TRG is scheduled to reconvene during the week of August 16, 1993.
l 1
9311190158 930817" PDR ADOCK 05000275 0
PDQ 93NCRWP\\93TPN028.SDL Page 1
of 28,
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NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 surveillance verifies the operability of SI pumps in accordance with ASME,Section XI.
In addition, this surveillance fully strokes SI pumps to RWST check valves SI-8919A and SI-8919B and partially strokes RWST to SI pumps suction check valve SI-8977.
STP P-1B is relied upon to satisfy the requirements of TS 3.5.2 and to verify that the non-operating SI pump does'not rotate in reverse.
STP V-15, "ECCS Flow Balance Test," is performed on a nominal 18-month refueling frequency.
The surveillance verifies the proper setting of the ECCS cold leg runout valves to assure proper flow using a single SI pump.
STP V-15 also verifies the full open stroke of SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B in ac ordance with ASME Section XI.
The IST Program Plan does not specify testing requirements for SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B reverse flow closure.
C.
Event
Description:
On March 3, 1984, for Unit 1 and on July 25, 1985, for Unit 2, initial entry to Mode 3 was made without reverse flow testing of safety-related SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B.
These discharge check valves were forward flow tested during STP V-15 testing.
On August 29, 1988, NRC Information Notice (IN) 88-70,
~'
" Check Valve Inservice Testing Program DefYciencien.," was issued to provide notification of potentia. problems identified during NRC inspections of check valve IST programs at several plants.
PG&E initiated a review of safety-related check valves at DCPP.
On April 3, 1989, NRC Generic Letter (GL) 89-04, l
" Guidance on Developing Acceptable Inservice Testing Programs," was issued noting similar generic concerns as IN 88-70 and requiring that implementing test procedures be reviewed and revised as necessary within 6 months of i
receipt of the Generic Letter.
GL 89-04 required no response from DCPP because the NRC had already completed their review of the DCPP IST Program Plan (in 1985).
The design basis of all check valves was reviewed against surveillance testing procedures for consistency with GL 89-04.
93NCRWP\\93TPN028.SDL Page 4
of 28 i
i-NCR DCO-93-TP-N02; nev.0C DRAFT: July 29, 1993 On July 11, 1989, the review of safety-related check valves initiated in response to IN 88-70 was completed.
As a result of the review in accordance with IN 88-70, several check valves in the containment spray system and the SI system were found to have a safety function in the closed position and were not reverse flow tested in accordance with ASME Section XI.
This condition was reported to the NRC in LER 1-84-044 on July 16, 1990.
The review of safety-reiated valves in accordance with IN 88-70 did not identify that SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B also have a safety function in the closed position, although they were included as a part of the review.
The check valve design basis review identified auxiliary feedwater (AFW) steam supply check valves MS-5166 and MS-5167 as not being included in th,e IST Lrogram Plan to verify their safety function in the closet position. On April 2, 1991, these additional check valve deficiencies were reported to the NRC via LER 1-84-044-01.
The review of safety-related valves in accordance with IN 88-70 and GL 89-04 did not identify that SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B as requiring reverse flow testing in accordance with ASME Section XI.
In 1991, as part of the GL 89-04 review program, the design bases safety function for SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B were identified in an informal communication from Nuclear Engineering and Construction Services (NECS) to System Engineering.
NECS defined SI pump discharge check valves 8922A and 8922B as preventing pump-to-pump interaction when discharge cross-tie valves SI-8821A and SI-8821B are open, thus ensuring stable miniflow operation for each pump.
1 The SI system engineer misunderstood the description of the design basis safety function in the NECS communication.
The system engineer believed that the i
design function was related to testing requirements and l
not a safety-related function.
In addition, the system l
engineer did not identify SI pump discharge check valves l
1-8922A, 1-8922B, 2-8922A, and 2-8922B as being required to be reverse flow tested in accordance with ASME Section XI.
Although the system engineer thought that testing of the SI pump discharge check valves was not required, as l
part of the GL 89-04 review program, the SI system I
engineer on November 5, 1991, recommended that modifications be made to STP P-1B to verify that SI pump 93NCRWP\\93TPN028.SDL Page 5
of 28
NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B perform their design function.
These recommendations were not followed up with formal recommendations or initiation of a plant action request.
Also, this recommendation was not tracked by the GL 89-04 action plan supervisor /IST coordinator due to an assumption that this recommendation was being tracked by initiation of a plant action request; and, it was not required to be administratively tracked by the GL 89-04 action plan.
On January, 8,
1992, as result of GL 89-04 the-design bases safety functions for SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B was formally-identified in a PG&E memorandum from NECS to Plant Engineering.
On April 17, 1993, a review of STP P-1B identified a potential SI leak path that could affect the minimum ECCS cold leg injection flows.
Also,-during this revi' it was identified that the reverse flow testing of the SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B were not included in the IST Program Plan.
On April 19, 1993 PG&E performed an operability assessment on the Unit 1 SI pump discharge check valves.
SI pump 1-1 was started, pressurizing the discharge piping to approximately 1600 psig.
The pump _was then shut down, and the discharge piping pressure was monitored for a decrease in pressure.
The pressura held at approximately 1600 psig for 20 minutec.
Since the suction pressure of the pump is 30,sig, bots SI discharge check valves'1-8922A and 1-8922B held a differential pressure of approximately 1570 PSID.
This test demonstrated that the valves do not leak.
If the valves had leaked even a small amount, the pressure would have decayed rapidly.
Therefore, SI discharge check vi.lves 1-8922A and 1-8922B will reverse flow seat.
In addition, prior to entering Mode 3 following the Unit 2 fifth refueling outage (2RS) similar tests were performed on SI discharge check valves 2-8922A and 2-8922B and the test results were consistent with the Unit 1 test results.
On June 25, 1993, following discussions with the SI pump discharge check valve vendor a Technical Review Group (TRG) determined that the SI purap discharge check valves should have been included in the IST Program Plan and' that testing which relied upon reverse pump rotation to identify reverse flow may not have been adequate to meet 93NCRWP\\93TPN028.SDL Page 6
of 23 1
i.
NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 the reverse flow seating requirements.
Although the SI pump discharge check valves were not reverse flow tested in accordance with ASME section XI, the information provided in section IV of this LER demonstrates that the SI pump discharge check valves have always been capable of performing their intended safety functions since initial Mode 3 entry.
SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B are required to be operable to meet the requirements of TS 3.5.2, we have conservatively taken the position that we previously have entered into an operating Mode not permitted per TS 3.0.4.
D.
Inoperable Structures, Components, or Systems that Contributed to the Event:
None.
E.
Dates and Approximate Times for Major Occurrences:
1.
March 3, 1984:
Event date.
Initial entry of Unit 1 into Mode 3.
TS 3.0.4 not met.
2.
July 25, 1985:
Event date:
Initial entry of Unit 2'into Mode 3.
TS 3.0.4 not met.
3.
July 11, 1989:
Review of safety-related valves initiated in response to IN 88-70 complete.
4.
November 14, 1991:
Review of testing methods for safety-related valves in response to GL 89-04 completed.
5.
January 8, 1992:
PG&E memorandum formally defines the safety function of SI discharge check valves 1-8922A&B and 2-8922A&B.
5.
April 17, 1993:
Reverse flow testing requirements for SI discharge check valves 1-8922A&B and 2-8922A&B were determined not to be included in the IST Program Plan.
93NCRWP\\93TPN028.SDL Page-7 of 28
+
NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 4.
June 25, 1993:
Discovery date. "TRG determined that STP P-1B is inadequate to meet the ASME section XI reverse flow IST test requirements.
F.
Other Systems or Secondary Functions Affected:
None.
G.
Method of Discovery.
l On April 17, 1993, during a review of STP P-1B, plant engineering identified a potential SI leak path that could affect the minimum ECCS cold leg injection flows.
On June 25, 1993, the TRG' determined that since SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B are required to be operable to meet the requirements of TS 3.5.2, entry into operating Mode 3 is not permitted per TS 3 0.4 without verification of i
operability.
H.
Operator Actions:
None.
I.
Safety System Responses:
I None.
III.
Cause of the Event A.
Immediate Cause:
ASME Section XI required inservice testing of reverse flow seating was not performed on SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B to verify that they would reverse flow seat.
B.
Determination of Cause:
1.
Human Factors:
a.
Communications:
A miscommunication occurred when the system engineer recommended including the check valve reverse flow testing in STP P-1B, and the IST coordinator did not follow through to ensure that the applicable procedures were modified.
93NCRWP\\93TPN028.SDL Page 8
of 28 4
4
i-NCR DCO-93-TP-N02; Rev.00 DRAFT: July 29, 1993 Misunderstanding of the design bases information.
The plant system engineer thought the safety function described was only required during the actual pump testing configuration and was not required for accident mitigation conditions.
b.
Procedures:
c.
Training:
d.
Human Engineering:
e.
Management System:
Following receipt of generic NRC guidance in IN 88-70 and GL 89-04, initial reviews did not identify the need to reverse flow test the SI pump discharge check valves due to deficiencies in the scope of the IST Program Plan review.
The initial reviews of the IST Program Plan was not systematically documented.
2.
Equipment / Material:
a.
Material Degradation: N/A.
b.
Design: N/A.
c.
Installation: N/A.
d.
Manufacturing: N/A.
e.
Preventive Maintenance: N/A.
f.
Testing: N/A.
i l
g.
End-of-life failure: N/A.
C.
Root Cause:
ASME Section XI, subsection IWV-3522, states that check i
valves shall be exercised to the position required to j
fulfill'their function.
Valves that are normally open during plant operation and function to prevent reverse flow shall be tested in a manner that proves that the disk travels to the seat promptly on cessation or reversal of flow.
Valves that are normally closed during l
plant operation and function to open on reversal of l
pressure differential shall be tested by proving that the disk moves promptly away from the seat when the closing l
93NCRWP\\93TPN028.SDL Page 9
of 28
NCR L20-93-TP-N028 Rev.00 DRAFT: July 29, 1993-pressure differential is removed and flow through the valve is initiated.
The SI pump discharge' check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B perform a safety function in both the open and closed positions.
Because the SI pump discharge check valves are normally closed-during plant operation and the SI pumps are idle, the check valves normally do not have a reverse pressure differential.
Plant Engineering did not interpret the above requirements as requiring that both open and closed positions of the SI discharge check valves be verified by testing.
Consequently, because the SI pump discharge check valves are normally closed during plant operation, the valves were classified as normally closed Category C valves and tested for full-stroke open capabilities.
During the development of the IST Program Plan a personnel error occurred because responsible personnel did not recognize the need to reverse flow test the check valves.
Reverse flow testing of these valves was not identified as an IST requirement by plant engineers during the detailed design review of the DCPP IST Program Plan in a working session with the NRC in 1983.
At that time, the NRC reviewed the adequacy of testing procedures for all components in the IST Program Plan.
Where testing deficiencies were identified, plant engineers revised appropriate STPs and the IST Program Plan.
The NRC followed up with several safety evaluation reports (SERs ), ultimately providing approval of_the current IST Program Plan in December 1988.
Following receipt of generic NRC guidance in,IN 88-70 and GL 89-04, initial reviews did not i_2ntify the need to reverse flow test the SI pump discharge check valves due to deficiencies in the scope of the IST Program Plan review.
The initial reviews of the IST Program Plan was not systematically documented.
In 1992, as part of the GL 89-04 review program, the design bases safety function for SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B were documented in a PG&E memorandum from NECS to Plant Engineering.
Following receipt of generic NRC guidance in IN 88-70 and GL 89-04, the later reviews did not identify the need to reverse flow test these valves due to the following:
1.
Misunderstanding of the design bases information.
The plant system engineer thought the safety function described was only required during the actual pump testing configuration and was not required for accident mitigation conditions.
93NCRWP\\93TPN028.SDL Page 10 of 28 l
l i*
i NCR DCO-93-TP-N028 Rev.00 j
DRAFT: July 29, 1993 l
2.
A miscommunication occurred when the system engineer recommended including the check valve reverse flow testing in STP P-1B, and the IST coordinator did not follow through to ensure that the applicable procedures were modified.
In summary, The root causes of this event include deficiencies in the scope of.he IST Program Plan review, j
miscommunication and personnel error (cognitive).
D.
Contributory Cause:
I To be determined.
t IV.
Analysis of the Event
(
A.
Safety Analysis:
During single pump operation, SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B serve to prevent leakage from the operating SI pump discharge back through the nonoperating SI pump during the injection phase.
The following operating and maintenance history summary l
indicates that SI pump discharge check valves 1-8922A, l
1-8922B, 2-8922A, and 2-8922B (on both Units 1 and 2 l
respectfully) are operable and capable of performing their intended safety function to close upon reversal of flow since initial Mode 3 entry.
l 1.
SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B have been observed to be leak tight on an incidental basis.
Following performance of STP P-1B, the discharge pressure was often observed to remain at SI i
pump discharge pressure.
This indicates that the SI pump j
discharge check valves 1-8922A, 1-8922B, 2-8922A, and j
2-8922B were leak tight, i
2.
The Unit 1 SI pump discharge check valves 1-8922A and 1-8922B were disassembled and inspected during the Unit 1 l
fifth refueling outage.
The inspection determined that i
there was no internal valve damage and a 360' seating l
surface blue check was satisfactory.
i 3.
The Unit 2 SI pump discharge check valve 2-8922A was inspected during the Unit 2 second refueling outage.
The l
inspection determined that there was no internal valve l
damage and a visual inspection of the valve seat was satisfactory.
The Unit 2 SI pump discharge check valve 2-8922B was disassembled and inspected during the Unit 2 i
93NCRWP\\d3 128.SDL Page 11 of 28
NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 second refueling outage.
The inspection determined that there was no internal valve damage and a 360' seating surface blue check was satisfactory.
The Unit 2 SI pump discharge check valve 2-8922B was disassembled and inspected during both the Unit 2 fourth refueling outage and 2RS, with similar results.
4.
A review of maintenance histories determined that no corrective maintenance has been required for-SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B.
5.
STP V-15, currently performed on an 18-month basis to meet the requirements of TS 4.5.2 action h.,
ensures that the stringent ECCS flow criteria for (including single SI pump operat!on) are met.
In accordance with the single failure criterion defined by the NRC in SECY 77-439, total valve disk failure or failure in the fully open position is not considered to be a credible failure mode based on the maintenance history of the valve, inspection results, and the service environment.
Therefore, any potential valve impairment is considered to be in the form of backleakage.
STP V-15 is currently performed on a nominal 18-month frequency and verifies adequate cold leg injection flows for single pump operation.
Verification of these. flows in V-15 demonstrates the nonoperating, SI pump's discharge check valve has seated, is not exhibiting excessive backleakage, and is not degrading the ability of the system to perform its safety function.
During a LOCA the SI pumps deliver water from the RWST to the RCS after the RCS pressure is reduced.
During single pump operation, SI pump discharge check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B serve to prevent leakage from the operating SI pump discharge back through the nonoperating SI pump.
If the discharge check valve of the opposite SI pump leaks, the fluid will flow through the idle SI pump, thereby potentially reducing the overall ECCS flow to the cold legs below the minimum acceptable amount.
In the event that both SI pumps are operating, reverse flow in either SI pump discharge check valve is not possible.
Surveillances performed on an 18-month basis to meet the surveillance requirements of TS 4.5.2 h.
(STP V-15) ensure that ECCS injection flow for single pump operation is within the TS minimum and maximum flow rates.
Thus, the failure to perform periodic reverse flow inservice testing on SI pump discharge check valves 1-8922A, 1-8922B, 93NCRWP\\93TPN028.SDL Page 12 of 28 l
1
NCR DCO-93-TP-NC:: Rev.00 DRAFT: July 29, 1993 l
l 2-8922A, and 2-8922B did not adversely affect the health and l
safety of the public.
1 B.
Reportability:
1.
Reviewed under QAP-15.B and determined to be non-conforming in accordance with Section 2.1.8.,
per manager of Technical Services.
2.
Reviewed under 10 CFR 50.72 and 10 CFR 50.73 per NUREG 1022 and determined to be reportable in accordance with 10 CFR 50.73 (a) (2) (i) (B).
The report associated with this NCR is LER 1-84-047-00.
3.
Reviewed under 10 CFR Part 21 and determined that this event or condition will not require a 10 CFR 21 report, since (a) it is being evaluated under 10 CFR l
50.72/73, and (b) it does not involve defects in vendor-supplied services / spare parts in stock.
4.
This event or condition (will, will not) be reported via an INPO Nuclear Network entry.
i To be determined.
5.
Reviewed under 10 CFR 50.9 and determined the event i
was not reportable under 10 CFR 50.9 since event was being reported under 10 CFR 50.73.
6.
Reviewed under the criteria of AP C-29 requiring the issue and approval of an OE and determined that an OE is not required.
V.
Corrective Actions A.
Immediate Corrective Actions:
l 1.
On April 19, 1993, testing was performed, demonstrating that SI pump check valves 1-8922A, 1-8922B are leak tight.
In addition, between 4/19/93 and 4/23/93 SI pump check valves 2-8922A and 2-8922B l
were tested and demonstrated satisfactory results.
j B.
Investigative Actions:
1.
Investigate the original Generic Letter 89-04 review and determine what the plan was, what type of training was conducted and how this was documented.
RESPONSIBILITY:
J.
Portney ECD:6/3/93 93NCRWP\\93TPN028.SDL Page 13 of 28
NCR DCO-93-TP-N028.Rev.00 DRAFT: July 29, 1993 l
STATUS: Return DEPARTMENT: System Engineering Tracking AR:
A0308538, AE #02 2.
Document the Information Notice 88-70 review.
RESPONSIBILITY:
J.
Portney ECD:6/3/93 l
STATUS: Return DEPARTMENT: System Engineering Tracking AR:
A0308538, AE #03 3.
Determine why the corrective actions for 91-TN-N026 were not effective.
RESPONSIBILITY:
D.
Spencer ECD:6/3/93 l
STATUS: Asignd DEPARTMENT: Plant Engineering Tracking AR:
A0308538, AE #04 4.
Reissue chron #182965 in a more systematic format (RHR, CVCs, SI).
RESPONSIBILITY:
L. Walter ECD:6/3/93 STATUS: Return DEPARTMENT: NECS Engineering Tracking AR:
A0308538, AE #05 5.
Reissue chron #182965 in a more systematic format for all other systems.
RESPONSIBILITY:
L. Walter ECD:8/13]93 l
STATUS: Asignd l
DEPARTMENT: NECS Engineering l
Tracking AR:
A0308538, AE #06
(
l 6.
Investigate reverse flow criteria used by other utilities, what is 0:K per ASME etc.
l RESPONSIBILITY:
D.
Spencer ECD:6/3/93 STATUS: Asignd DEPARTMENT: Plant Engineering Tracking AR:
A0308538, AE #07 7.
Check other SI pump check valves.and testing configurations for proper testing of pump interaction.
l RESPONSIBILITY:
E. Chaloupka ECD:6/3/93 l
STATUS: Return DEPARTMENT: Plant Engineering 93NCRWP\\93TPN028.SDL Page 14 of 28
W NCR DCO-93-TP-N028-Rev.00 DRAFT: July 29, 1993 Tracking AR:
A0308538, AE #09 9.
Review SI-b922A/B & SI-8919A/B tests during plant startup for potential missed surveillances.
RESPONSIBILITY:
E. Chaloupka ECD:6/3/93 STATUS: Return DEPARTMENT: Plant Engineering Tracking AR:
A0308538, AE #08 9.
Investigate reportability per T.S.
4.0.5 and make l
recommendations to TRG. Determine if modes can be changed without sufficient testing.
RESPONSIBILITY:
E. Chaloupka ECD:6/3/93 STATUS: Return DEPARTMENT: Plant Engineering Tracking AR:
A0308538, AE #10
- 10. Determine how much leakage is acceptable and what flow would cause the Safety Injection pump to rotate.
Determine if reverse rotation would be an adequate l
test of safety function.
I RESPONSIBILITY:
P.
Beckham ECD:6/8/93 Status: Return DEPARTMENT: NECS Engineering Tracking AR:
A0308538, AE #11 l
l
- 11. Determine root cause for not including valves in IST program.
RESPONSIBILITY:
J.
Portney ECD:6/8/92 l
STATUS: Asignd DEPARTMENT: System Engineering Tracking AR:
A0308538, AE #12
RESPONSIBILITY:
R. Kelmenson ECD:6/24/93 STATUS: Return DEPARTMENT: NRS/Regcom Tracking AR:
A0308538, AE #13
- 13. Evaluate reportability as if determination were made l
that testing was inadequate.
RESPONSIBILITY:
R.
Kelmenson ECD:6/8/93 l
STATUS: Asignd l
93NCRWP\\93TPN028.SDL Page 15 of 28
NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 DEPARTMENT: NRS/Regcom Tracking AR:
A0308538, AE #14
- 14. Investigate and establish the acceptance criteria for the charging pumps 100 lb. DP.
RESPONSIBILITY:
P. Beckham ECD: 7/9/93 l
STATUS: Return DEPARTMENT: NECSNE Tracking AR:
A0308538, AE #15
- 15. Review current IST plan and testing of.RHR pump discharge check valves to ensure that they are adequately tested for' reverse flow.
RESPON.oIBILITY:
J.
Grammer ECD: 7/9/93 STATUS: Return DEPARTMENT: SYSENG Tracking AR:
A0308538, AE #16
- 16. Prepare and submit an LER to the NRC for this nonconformance.
RESPONSIBILITY:
S.
LaForce ECD: 7/26/93 DEPARTMENT: PTRC STATUS: Return Tracking AR:
A0308538, AE #17-
- 17. Evaluate past operability of SI check valves.
RESPONSIBILITY:
J.
Portney ECD: 7/9/93 l
STATUS: Asignd DEPARTMENT: SYSENG Tracking AR:
A0308538, AE #18 g
- 18. Determine whether SI check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B are Category A or C.
RESPONSIBILITY:
E.
Chaloupka ECD: 7/31/93 STATUS: Asignd DEPARTMENT: PTEX Tracking AR:
A0308538, AE #TBD C.
Corrective Actions to Prevent Recurrence:
1.
Add a pressure drop test for SI check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B to the Unscheduled outage item list to be performed during a Mode 4 or Mode 5 forced outage for Unit 1 or Unit 2.
The pressure drop test will verify reverse flow seating 93NCRWP\\93TPN028.SDL Page 16 of 28 P
q
- - ~ _ - _.. -
I i
l i
)
l l
\\
6' NCR DCO-93-TP-N 23 Rev.00 DRAFT: July 2,,
1993
'I for SI check valves.1-8922A, 1-8922B or 2-8922A, and 2-8922B.
RESPONSIBILITY:
J. Galle ECD: 7/20/93 l
STATUS: Asignd DEPARTMENT: SYSENG Tracking AR:
'A0308538, AE #20 Outage Related? Yes-OUTAGE:(U1 FO.and U2 FO)
OE Related?
ics NRC Commitment? Yes CMD Commitment? Yes 2.
The IST Program Plan will state the function and the type of periodic testing required for SI pump discharge check valves'l-8922A, 1-8922B, 2-8922A, and
?
2-8922B, and the appropriate procedures will be-l revised prior to 1R6 and 2R5.
i RESPONSIBILITY:
D.
Spencer ECD:08/31/96 STATUS: Asignd DEPARTMENT: System Engineering i
l Tracking AR:
A0308538, AE #21 Outage.Related? Yes OUTAGE:(1R6 and 2R6)
OE Related?
Yes/No NRC Commitment? Yes/No CMD Commitment? Yes/No 3.
The DCPP IST Program Plan for the second ten-year period will be revised and submitted to the NRC.
t During the revision process, the following corrective actions will be performed:
a.
The IST Program Plan wi.1 comply with current guidance in GL 89-04.
b.
Safety-related testing procedures'will be reviewed for compliance with the current guidance in GL-89-04'and revised as needed.
c.
All safety-related' pumps and valves included in-the IST Program Plan will-be reviewed to determine if they should be added to the IST.
Program Plan per ASME Section XI' and.GL 89-04.
d.
All safety-related pumps and valves ~not included in'the IST Program' Plan will be~ reviewed for-compliance with the current guidance in ASME
)
Section XI and GL 89-04.
93NCRWP\\93TPN028.SDL Page 17 of'28;
NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 e.
The bases for why a safety related pump or valve is included or excluded in the IST Program-will be documented.
f.
The IST Program Plan will receive an independent review by an'outside contractor specializing in IST program reviews.
RESPONSIBILITY:
D.
Spencer ECD:08/31/96 STATUS: Asignd DEPARTMENT: System Engineering Tracking AR:
A0308538, AE #21 Outage Related? No-OE Related?
No NRC Commitment? Yes CMD Commitment? Yes NOTE:
The submittal of the second ten year IST.
Program Plan is a commitment to the NRC.
The individual actions (a-f) were not specifically committed to the NRC.
D.
Prudent Actions (not required for NCR closure)
To be determined.
RESPONSIBILITY:
Tracking AR:
A0~
ECD:
VI.
Additional Information A.
Failed Components:
None.
B.
Previous Similar Events:
NCR DCO-89-TN-N049/LER 1-84-044 " Check Valve Back Flow Inservice Testing Deficiencies" and NCR-DCO-91-TN-N026/LER 1-84-044-01, Check Valves Inservice Testing Deficiencies Due to Personnel Error, submitted to the NRC on July 16, 1990.
On February 20, 1984, for Unit 1 and on July 19, 1985, for Unit 2, initial entry to Mode.4 was made without complete inservice testing of certain check valves.
On March 3, 1984, for Unit 1 and on July-25, 1985, for Unit 2, initial entry to Mode 3 was made without closure testing of check valves MS-5166 and j
MS-5167.
The check valves were not being tested to 93NCRWP\\93TPN028.SDL Page 18 cf 28
i 1
NCR DC0-93-TP-N028 Rev.00 DRAFT: July 29, 1993 verify their safety function in the closed position in accordance with ASME Section XI IST requirements.
J l
The IST deficiencies were caused by a personnel error.
Plant system engineering did not correctly identify testing requirements for these check valves in the closed position.
Corrective actions to prevent recurrence include: the testing requirements of components in the IST Program were reviewed to ensure consistency with the guidance of NRC Generic Letter 89-04; the IST Program has been revised to accurately reflect the proper testing requirements for these check valves; and check valves in the IST Program were reviewed to confirm that the Generic Letter 89-04 review considered all appropriate design basis requirements.
The corrective actions described in LER 1-84-044-00 could not-have prevented the event described in this LER since the corrective actions were performed several years after the event date described in this LER.
However, these corrective actions should have identified the condition described in this LER.
NCR DC0-91-TN-N048, "IST Generic Letter 89-04 Requirements" On 5/24/91, during a review of STP V-18 it was discovered that valves SI-8900 A tnrough D, SI-8905 A through D and SI-8819 A through D were not individually measured for full flow, contrary to the requirements of GL 89-04.
However, through the performance of STP V-15/V-4A the subject valves were verified to stroke open to pass the post-accident flow rates, and therefore the IST requirements were met and this event was not reportable.
The root cause of this event was personnel error, in that the responsible personnel did not recognize the need to measure the flow through the subject valves individually in accordance with Position 1 of GL 89-04.
NCR DCO-90-TN-N069/LER #TBD During a review of STPs, it was discovered that several pump STPs were not in compliance with the requ,irements of ASME Section XI, "ASME Boiler and Pressure Vessel Code." Several STPs specified data to be taken before stabilization of bearing temperature in violation of ASME Section XI.
STP P-2B specified 93NCRWP\\93TPN028.SDL Page 19 of 28 t
h
,e
NCR DCO-93-TP-N028 Rev.00 1
DRAFT: July 29, 1993 a change in flow through the system before all necessary data was taken in violation of Section XI.
The root cause for the unstabilized bearing temperature requirement deficiency was determined to be personnel error in that the procedure writers misinterpreted the requirements of ASME Section XI step IWP-3500 (b).
The root cause of the flow requirement deficiency was determined to be personnel error in that the procedure writer overlooked t'._
requirement of Section XI due to a concern for protection of plant equipment.
b l
L 93NCRWP\\93TPN028.SDL Page 20 of 28
_ ~ _ _
^
NCR DCO-93-TP-r?28 Rev.00 DRAFT: July 29, 1993 NCR DCO-92-TN-N008/LER 1-92-001-00, Violation of Technical Specification 4.0.5 Due to a Previously Unidentified Check Valve Safety Function.
On April 1, 1992, it was determined that Units 1 and 2 were in violation of Technical Specification 4.0.5, since volume control tank outlet check valve CVCS-8440 was not being tested in accordance with ASME Section Xi.
The root cause for the exclusion of CVCS-8440 from the ASME Section XI. Inservice Testing Program was that its safety function _had not previously been identified.
Corrective actions.to prevent recurrence included a review of all valves in the post-LOCA recirculation flow path to determine if any other valves perform a i
previously unidentified safety function due to a l
similar configuration.
This review would not have identified the condition described in this event, because the review was limited to post-LOCA
~
recirculation flow paths that may potentially leak to the atmosphere; the nonconformance described in this LER did not fall into the scope of the review associated with LER 1-92-001.
C.
Operating Experience Review:
1.
NPRDS:
Contact Reliability Engineering for an NPRDS-search or Not applicable.
2.
NRC Information Notices, Bulletins, Generic Letters:
l See Event Description of this NCR.
3.
The NRC issued SSER 31 in 1985 which provided their evaluation of the DCPP IST plan.
Additional SSERs j
evaluated revisions to the plan.
j i
D.
Trend Code:
Responsible department __, and cause code __.
j To be determil;ed.
93NCRWP\\93TPN028.SDL Page 21 of 28 l
4 NCR DC0-93-TP-N028 Rev.00 DRAFT: July 29, 1993 E.
Corrective Action Tracking:
l l
1.
The tracking action request is A0308538.
2.
Are the corrective actions outage related?
To be determined.
F.
Footnotes and Special Comments:
None.
G.
References:
1.
Technical Specification 3.5.2, 3.0.4, and 4.0.5 2.
Initiating Action Request A0303706 3.
Previous NCRs:
NCR DCO-89-TN-N049/LER 1-84-044 " Check Valve Back Flow Inservice Testing Deficiencies" NCR DCO-90-TN-N069/LER ?????
)
NCR DC0-91-TN-N048, "IST Generic Letter 89-04 Requirements" NCR DCO-91-TN-N026/LER 1-84-044 "IST Program" NCR DCO-92-TN-N008/LER 1-92-001 "CVCS Reverse Flow" 4.
Previous NRC correspondence:
NRC Generic Letter 89-O' dated Aplil 3, 1989 NRC Information Notice 88-70 dated August 29, 1988 5.
ASME Section XI, Article IWV-1000 to 3700.
H.
TRG Meeting Minutes:
1.
On May 20, 1993, the TRG convened and considered the following:
a.
Investigation of the original Generic Letter 89-04 review, what the plan was, what type of training was conducted and how this was.
documented.
93NCRWP\\93TPN026.SDL Page 22 of 28
^
NCR DC0-93-TP-N028 Rev.00 DRAFT: July 29, 1993
]
b.
Reviewing the documentation of the Information Notice 88-70 review, c.
Determine why the corrective actions for 91-TN-N026 were not effective, d.
Reissuing chron #182965 in a more systematic format (RHR, CVCs, SI).
e.
Reissuing chron #182965 in a more systematic format for all other systems, f.
Investigating reverse flow criteria used by other utilities, what is OK per ASME etc.
g.
Checking other SI pump check valves and testing configurations for proper testing of pump interaction.
h.
Reviewing SI-8922A/B & SI-8919A/b tests during plant startup for potential missed surveillances.
i.
Investigation of reportability per T.S.
4.0.5 and making recommendations to TRG. Determine if modes can be changed without sufficient testing.
TRG to reconvene on 6/3/93 at 10:00 AM to hear results of investigative actions.
2.
On June 3, 1993 the TRG reconvened. Reports of the investigative actions were made.
The 1990/1991 effort to comply with GL 89-04,
" Guidance on Developing Acceptable Inservice Testing Programs", included training of all systems engineers in a half day class.
The basis of the training was GL 89-04 and included all valves in their system. It included a review of the IST program and its intent.
Training was documented in an Email.
The review resulted in the development of valve tables sent to McCoy Burgess last year.
The review looked at valves with respect to the IST program and functionality of 1
the valves.
No response or required actions were necessary by DCPP for GL 89-04 because the NRC had j
already completed their review of the IST program which was documented in SSER 31 (May 1985).
PG&E continued to maintain its program in line with GL 89-04 and NCR DCO-92-TN-N026 to avoid problems with the j
NRC. In addition to the GL 98-04 and the SSER 31 i
review, PG&E initiated a review of the safety related j
93NCRWP\\93TPN028.SDL Page 23 of 28 i
s.
NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 l
l check valves under Information Notice 88-70, " Check Valves Inservice Testing Program Deficiencies."
The IN 88-70 review checked to make sure appropriate valves were in plan and took one week.
The GL 89-04 was a much more comprehensive review.
Corrective actions made for DCO-91-TN-N026 were not effective for the follawing reasons:
a.
Instructions in the A/R were "... review check valves in the DCPP IST Program Plan to confirm that the GL 89-04 performed in corrective action B.1 from DC1-91-TN N026 considered appropriate design basis requirements.
This is very vague and open to different interpretations.
There may not be a clear understanding of what the final goal was, b.
NECS prepared a complete review of all the IST Program Plan's pump discharge check valves including the safety functions in both the open and closed direction. The system engineers received this but may not have completely understood how to tie this information back to the above request.
There also seems to have been no followup.
Corrective Actions to DC1-91-TN-N026 may have been more effective if documentation was. requested as to why each pump's discharge check valve did not require closure testing. GL 89-04 specifically listo pump discharge check valves as valves frequently not back flow tested. There appears not to have been an identification of clearly defined goals and deficient communications among the TRG, System Engineering and NECS.
The ASME reverse flow criteria is in Section XI, Subsection IWV-3522.
It states that," Confirmation that the disk moves away from.the seat shall be by visual observation, by an electrical signal initiated by a position indicating device, by observation of substantially appropriate pressure indications in the system, or by other positive means."
Other positive means could include observation of the nonrunning pump to assure that it is not rotating.
We presently use this method in several pump tests but we do not have consistent and/or thorough justification for-this method.
93NCRWP\\93TPN028.SDL Page 24 of 28
s' NCR DCO-93-TP-F^'8 Rev 00 DRAFT: July _29, 1993 The TRG to reconvene on June 9, 1993 to review additional investigative actions-and to determine reportability.
On June 9 the TRG reconvened.
The TRG considered that the GL 89-04-review was not as systematic as it-should have been and that it appears that a resubmittalifor each Unit will be required.
These submittals will..a in April 95 for Unit 1 and August _
~
96 for Unit 2.
While this next.10 year. review will be more systematic, it.does not. appear;that there was a wholesale breakdown in the program. Since.the'TRG-determined that.this event is reportable, this fact must be included as a statement in the LER.
The LER.
is due on July 9, 1993.
The TRG reviewed the GL 89-04 process.which included:
Train system engineers on.GL 89-04 and ASME'Section XI.
System-Engineers reviewed NECS'sElist of valves and safety functions. (There was no cross talk to verify list unless specific problems were noted.)
System Engineers documented review and concurrence.
No apparent open items resolution.
~
Review of IST Plan for inclusion of identified valves.
The above activities were conducted under.a self induced-deadline which may have-impacted the results.
An improved program will be given the time it needs and will include a review of a list of valves-in-the system, make a determination of which valves are required to be in the program and:whatftests are required, detennine what-tests we do, ~ review if it is in the plan or not, and finally write ARs to implement necessary changes.
The TRG recommended three corrective' actions:
They include: 1) Identification of ESF pumps'and Non ESF pumps which use reverse rotation"to verify-seating of discharge check valves and determine - if adequate. For those valves where reverse rotation-testing is inadequate, evaluate for nonconformance:with respect to GL 89-04, 93NCRWP\\93TPN028.SDL Page 25 of 28
NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 The TRG also wanted to take credit for the 2RS pressure tests identified in A0303706 AE# 01 as an immediate corrective action.
A STATUS search for GL 89-04 commitments in letters to the NRC was requested.
The TRG reconvened on June 25, 1993.
The TRG reviewed and discussed reportability of this event.
Information was presented to the TRG revealing that the SI pump manufacturers have indicated that their-pumps may not reverse rotate until 100 gallons per minute (GPM) is allowed to pass through.the_ pump.
Since design allows for a maximum leakage of 20_gpm and still assure sufficient SI flow, STP P-1B could not definitively determine if the leakage was below 20 gpm.
As a result of this new information the event was determined to be reportable unde. TS 3.0.4 as an entry into an operating mode with potentially inoperable Safety Injection Pumps.
The event date would be Mode 3 (HOT STANDBY) entry for each unit.
The discovery date is 6/25/93, _on this date the TRG evaluated all available information and made a preliminary reportability determination.
It was discussed in previous TRG meetings that this event may reportable as a missed surveillance under T.S.
4.0.5.
The TRG evaluated new information presented by Regulatory Compliance.
Subsequently, it was determined that this event is not reportable as a missed surveillance.
The bases for this determination is contained in the NRC Summary of meeting (held on: May 7, 199'i with NUnARC, BWROG, NUBARG, LER/JCO Committee, and others on comments on Draft NUREG-1022, Rev.
1.
The NRC concluded that missed surveillances are only reportable Lif the allowable extension + limiting condition for operation action times are exceeded.
The TRG discussed the safety significance of this event.
The TRG agreed that safe operation of the plant was never jeopardized.
The TRG discussed the operability _of the SI system due to the reverse flow or leak testing of valves SI-8922 A&B (SI pump discharge check valves) not included in the IST Program Plan.
The system engineering representative notified the TRG that a POA test was performed on the Unit 1 SI pump discharge check valves 1-8922 A&B.
The test demonstrated that the valves do not leak.
See the 93NCRWP\\93TPN028.SDL Page 26 ef 28
w NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 event description of this NCR for more information cn1 the POA test.
The TRG suggested that Regulatory' Compliance talk with the NRC to determine their expectations for the reporting of future deficiencies in the'IST program.
The TRG reconvened on July 13, 1993 and discussed the following: draft LER 1-84-047-00, root'cause,.
outstanding investigative actions, and.two new actions.
The TRG agreed that the central issue of this event was: That the. safety function 1of these valves have always been known (the design basis of the SI-discharge check valves were formally: documented in a NECS memorandum), but the valves were not included in
~
the IST Program Plcn.
The TRG agreed that the root cause of this event was personnel error in that the SI pump. discharge check valves had previously identified as safety related valves, but were not included in the IST Program Plan.
The TRG discussed the categorization of the SI pump-discharge check valves.
They are. currently categorized as category C.
The question:was; asked:
Should we categorize these valves as category A?.
Subsequently, the following investigative action was assigned:
e Determine whether SI. check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B are Category A or C.
l RESPONSIBILITY:
E. Chaloupka ECD: 7/31/93 The TRG discussed what would happen if one of the Units had an unplanned outage.
The TRG agreed that a differential pressure test to verify that the.SI pump discharge check valves reverse flow seat should be '
j added to the unscheduled outage item list.
i Subsequently, the following action-was assigned:
Add a pressure drop test'for-SI check valves 1-8922A, 1-8922B, 2-8922A, and 2-8922B to the Unscheduled outage item list to be performed during a Mode 4 or Mode 5 forced outage-for Unit 1 or Unit 2.
The pressure drop test will verify.
93NCRWP\\93TPN028.SDL Page 27 of 28
s-NCR DCO-93-TP-N028 Rev.00 DRAFT: July 29, 1993 reverse flow seating for SI check valves 1-8922A, 1-8922B or 2-8922A, and 2-8922B.
RESPONSIBILITY:
J. Galle ECD: 7/20/93 In addition, the following corrective action was assigned:
The DCPP IST Program Plan for the second ten,2ar period will be revised and submitted to the NRC.
The TRG agreed to reconvene on July, 16, 1993 to discuss the draft LER, root cause, and corrective actions.
The TRG reconvened on July 16, 1993 and discussed the following:
Draft LER, root cause, and corrective actions.
The Regulatory Compliance representative presented a timeline of the events to the TRG.
The TRG discussed the timeline and the direction of the draft LER.
The TRG agreed that the past events (LER 1-84-044-00 and 01), IN 88-70, and GL 89-04 should be a part of the Event and the root cause.
The TRG agreed that the root cause from the previous TRG meeting did not cover the entire event.
Thus, the TRG agreed that the root cause would be covered by three parts: (1)
ASME Section XI description and shortcomings, (2)
" Evolution of knowledge" during the time period of IN 88-70, GL 89-04, and_ associated LERs/NCRs, and (3)
Personnel error / misunderstanding involving the NECS design basis and SI pump system engi.;eer email to IST coordinator.
The TRG agreed to reconvene by August 18, 1993.
I.
Remarks:
- None, 93NCRWP\\93TPN028.SDL Page 29 of 28