Part 21 Report - 1995-085
ACCESSION #: 9503020053
NTD-NRC-95-4403
Westinghouse Energy Systems (illegible print)
Electric Corporation
February 20, 1995
U.S. Nuclear Regulatory Commission
Attn: Document Control Desk
Washington, DC 20555
Subject: Update to 10CFR21 Report Contained in Westinghouse Letter NTD-
NRC-94-4320, dated 10/19/94 and Status Report Contained in
Westinghouse Letter NTD-NRC-94-4361, dated 12/21/94
Reference: 1. Letter NTD-NRC-94-4320, N. J. Liparulo to Document
Control Desk, 10/19/94
2. Letter NTD-NRC-94-4361, N. J. Liparulo to Document
Control Desk, 12/21/94
3. Westinghouse Nuclear Safety Advisory Letter, NSAL-94-
023, 10/26/94
The following information is provided as an update to the 10 CFR 21
report that was previously identified to you in References 1 and 2.
BACKGROUND
Reference 1 identified a defect, as defined under 10CFR21, regarding the
pressure reducing sleeve locknut of the JHF Model Safety Injection Pump
that was manufactured by Ingersoll Dresser Pump (IDP) Company and
supplied to several nuclear power plants by Westinghouse and IDP.
Westinghouse also notified the affected licensees about the defect via
Reference 3.
Reference 1 indicated that IDP would perform a review of the applicable
400 series stainless steel parts and applicable heat treatments on other
safety related pumps it supplied to the nuclear power industry to
determine whether this situation could apply to other parts on other
safety related pumps. This review was completed on December 15, 1994.
Westinghouse notified the NRC about the results of this review via
Reference 2. The results of the review indicated that the failure
mechanism appears to be limited to IDP pump parts that consist of 416 SS,
processed under IDP heat treatment process "HT 21"" and taken from IDP
heat numbers #15899 and #28144. Also, the review indicated that
additional pump parts may be susceptible to the same failure mechanism.
Reference 2 indicated that IDP would determine whether the failure of the
additional pump parts would prevent the applicable pump from performing
its intended safety function.
This review has been completed and indicates that some of the additional
pump parts may also constitute a defect, as defined in 10 CFR 21, which
could create a substantial safety hazard. The following report provides
more information about these additional pump parts.
EVALUATION
IDP's evaluation results indicate that all 416 SS parts processed under
IDP heat numbers #15899 and #28144 are susceptible to the same failure
mechanism as the pressure reducing sleeve locknuts. These parts have been
divided into three categories.
The first category includes parts which were supplied with the original
pump assembly and whose failure could prevent the pump from performing
its intended safety function. These parts and the applicable plants are
identified in Table 3. Also, note that these parts include the pressure
reducing sleeve locknuts that were the parts originally identified in
Reference 1.
The second category includes parts which were supplied with the original
pump and whose failure would not prevent the pump from performing its
intended safety function. These parts are identified in Table 4. The
parts should be replaced as a prudent maintenance activity. It should be
emphasized that these parts do not constitute defects pursuant to 10 CFR
21 since the failure of the parts should not prevent the pump from
performing its intended safety function. However, they are included in
this letter to identify the results of the evaluations that are mentioned
in References 1 and 2.
The third category includes the parts which were supplied as replacement
pump parts and whose failure could prevent the pump from performing its
intended safety function. Most of the replacement parts were supplied
directly to the utilities by IDP. These parts and the applicable plants
are identified in Table 5. Please note that Table 5 has been divided into
two lists. One list ("Parts from Identified Material") includes the
replacement parts that are known to have been taken from heat #15899 and
#28144. The other list ("Parts from Unidentified Material") includes
those parts which could have been manufactured from either heat #15899 or
#21844, based on the time of manufacture original material specification
and part size. However, there is no documentation to specifically
identify the heat number from which the part was taken. Therefore, it was
assumed that the parts were taken from heat #15899 and #21844.
The identification of the parts in Tables 3, 4 and 5 is based on several
reported part failures, a failure analysis of failed parts and
engineering judgement. Duke Power Company reported two separate failures
(cracking) of the pressure reducing sleeve locknuts on JHF model safety
injection pumps. Both locknuts consisted of 416 SS and were processed
under heat #15899. Duke Power performed a failure analysis on each
locknut. The failure analysis indicated that the failure mechanism was
stress corrosion cracking. The analysis also indicated that each
locknut's susceptibility to stress corrosion cracking was increased by a
relatively high martensite phase harness which allegedly resulted from an
insufficient tempering operation. A comparison of the Duke Power Failure
analysis report and the IDP heat treatment specification and heat
material certification is provided in Table 1.
Table 1: Pressure Reducing Sleeve Locknut - Comparison of Duke
Power Company Failure Analysis to IDP Heat Treatment
Specification and Material Certification
Hardness (Re)
First Locknut Second Locknut
Failure Analysis - Bulk Phase 35 32-33
Failure Analysis - Microhardness 45-49 42-44
Heat Treatment "HT21" Specification 27-32
Heat #15899 Material Certification
Bulk Phase Hardness 27
The existence of two failures and the data in Table 1 provide a basis to
conclude that the locknuts are defects as defined in 10 CFR 21. First,
it should be noted that 400 series SS with a hardness of greater than 40
Rc is very susceptible to intergranular stress corrosion cracking in
aqueous environments. Table 1 indicates that for both locknuts, the
microhardness was higher than 40 Rc. Also, Table 1 indicates that for
both locknuts, the bulk phase hardness measured in the failure analysis
was significantly higher than the bulk phase hardness provided on the
material certification sheet. It could not be determined why these bulk
phase hardness values are different. Sine, the microhardness was greater
than 40 Rc, the bulk phase hardness difference could not be attributed to
any specific reason. However, since the cracking was observed on each
locknut, it was determined that all parts from heat #15899 could be
susceptible to the same failure.
In addition to the above, Duke Power Company recently discovered cracking
on a spacer sleeve in another JHF model safety injection pump. The
spacer sleeve consisted of 416 SS and was processed under IDP heat
treatment specification "HT 21". However, the spacer sleeve was taken
from a different heat which was heat, which was heat #28144. Duke Power
performed a failure analysis on the spacer sleeve and determined that the
failure mechanism was also stress corrosion cracking. Also, the failure
analysis indicated that the spacer sleeve's hardness made the sleeve
marginally acceptable for service in aqueous environments. A comparison
of the Duke Power Failure analysis report and the IDP heat treatment
specification and heat material certification for the spacer sleeve is
provided in Table 2.
Table 2. Impeller Spacer Sleeve - Comparison of Duke Power
Company Failure Analysis to IDP Heat Treatment Specification
and Material Certification
Hardness (Rc)
Failure Analysis - Bulk Phase 26-30 (1)_/
Failure Analysis - Microhardness 33-39
Heat Treatment "HT21" Specification 27-32
Heat #21844 Material Certification - 27
Bulk Phase Hardness
The existence of the cracked spacer sleeve and the data in Table 2
provide a basis to conclude that the spacer sleeve is a defect as defined
in 10 CFR 21. First, the measured microhardness of 33-39 Rc is
higher than the material certification value of 27 Rc. It is less than
40 Rc, but nonetheless is marginally susceptible to stress corrosion
cracking in aqueous environments. The bulk phase hardness range is
somewhat higher than the material certification value, but it is still
within the heat treatment specification range of 27-32 Rc. Based on this
information, it was concluded that all parts used from heat #28144 could
be susceptible to the same failure mechanism.
Finally, and as mentioned, Tables 1 and 2 indicate that there is some
difference between the bulk phase hardness and the material certification
values. There are no apparent reasons for these differences.
Furthermore, Tables 1 and 2 indicate that there are significant
differences between the bulk hardness and the microhardness values.
There are no apparent reasons for these differences; however, it may be
postulated that the differences are attributable to insufficient
tempering. IDP has
_____________________________
(1)_/ This value was determined from the uncracked spacer sleeve on
the same pump. Both the uncracked and cracked sleeves were
taken from Heat #28144.
not received any additional reports of part failures involving 416 SS
under heat treatment specification "HT21." Therefore, it was concluded
that the failures should be limited to only those parts that were taken
from heats #15899 and #21844.
Table 3 identifies all pump parts that were originally supplied with a
pump, taken from heat #15899 and #28144 and whose failure could prevent
the applicable pump from performing its intended safety function. Table
4 identifies the parts that were originally supplied with a pump, taken
from heat #15899 and #28144 and whose failure would not prevent the pump
from performing its intended safety function. However. it is
recommended that the plan in Table 4 be replaced as a prudent maintenance
practice. Finally, Table 5 identifies the replacement pump parts that
were either supplied or believed to have been supplied from heat #15899
and 28144 and whose failure could prevent the applicable pump from
performing its intended safety function.
SAFETY SIGNIFICANCE
The safety significance for the failure of each part identified in Tables
3, 4 and 5 is provided as follows. The failure of the parts in Tables 3
and 5 could prevent the pump from operating. For Table 4, the part
failure should not prevent the pump from operating. More detailed
information for the parts identified in Tables 3, 4 and 5 will be
provided directly to each utility.
The pumps identified in Table 3 are all JHF model safety injection pumps.
These pumps are used in the intermediate head safety injection system for
the applicable plants. The loss of these pumps during the short term
mitigation period of a loss of coolant accident (LOCA) would impair the
plant's ability to mitigate the consequences of the LOCA. The loss of
the pump (or pumps) would reduce the overall flow to the core, which
could create a condition that is a substantial safety hazard.
The pumps identified in Table 5 include the intermediate head safety
injection, auxiliary feedwater, and charging/safety injection pumps. The
intermediate head pumps are discussed above. The auxiliary feedwater
pumps are used to provide feedwater to the steam generators during
certain accident conditions. The loss of these pumps during a feedwater
line break accident would impair the plant's ability to recover from the
break. The loss of the pump (or pumps) would reduce the available
secondary side cooling, which could create a condition that is a
substantial safety hazard.
The charging/safety injection pumps are used in the high head safety
injection system for the applicable plants. The loss of these pumps
during the short term mitigation phase of a LOCA would impair the plant's
ability to mitigate the consequences of the LOCA, especially for a small
break LOCA. The loss of the pump (or pumps) would reduce the overall
flow to the core, which could create a condition that is a substantial
safety hazard.
RECOMMENDATIONS
The following recommendations are proved for this issue.
1. Review Tables 3, 4 and 5 to determine whether the plant has any
parts that could be affected by this failure mechanism. The parts
identified in Table 3 and 5 are considered defects as defined in 10
CFR 21. Although the parts in Table 4 are not considered defects
pursuant to 10 CFR 21, the parts in Table 4 should eventually be
replaced as a prudent maintenance practice since these parts are
susceptible to the same failure mechanism.
2. Compare the information for the part in Tables 3, 4 and 5 to
determine whether the part is currently installed on the pump. In
some cases, this part may have been changed after the part was
supplied.
3. For parts in Table 3 and 5, if it is determined that the pump part
is currently installed on the pump, then the following should be
considered. First, as indicated in Table 5, if the affected part is
a shaft sleeve compression nut or a shaft sleeve collar, the part
can be inspected for cracking without disassembly of the pump.
Alternatively, if the affected part can not be inspected without
disassembly of the pump and it is not practical to immediately
disassemble the pump, then the pump operating history should be
reviewed relative to the mechanism for stress corrosion cracking.
The mechanism for stress corrosion cracking is dependent upon
several factors including, but not limited to, the amount of stress
placed on the part, the time the part is exposed to that stress, the
time exposed to an aqueous environment and the physical dimensions
of the part. By reviewing these factors, it may be possible to
demonstrate that the part failure is not imminent and/or that the
part will not fail in a manner that will prevent the pump from
performing its intended safety function. However, it is ultimately
recommended that the part be replaced with the part currently
recommended by IDP.
The above information is being concurrently transmitted to affected
utilities via supplement to Westinghouse letter NSAL-94-023.
If you have any questions regarding this transmittal, please contact H.
A. Sepp of my staff on 412/374-5282.
Very truly yours,
N. J. Liparulo Manager
Nuclear Safety Regulatory and Licensing Activities
JWF/p
cc: R.E. Joines/IDP
G. Morrissey/IDP
Table 3 "ORIGINAL CONSTRUCTION PUMP PARTS FROM HEAT #15899 AND #28144,"
2 pages omitted.
Table 4 "ORIGINAL CONSTRUCTION PUMP PARTS FROM HEAT #15899 AND #28144,
REPLACEMENT OF PART IS NOT MANDATORY," 2 pages omitted.
Table 5 "REPLACEMENT PUMP PARTS FROM HEAT #15899 AND #28144," 2 pages
omitted.
GENERAL INFORMATION or OTHER EVENT NUMBER: 28412
LICENSEE: WESTINGHOUSE ELECTRIC CORPORATION NOTIFICATION DATE:
02/20/95
CITY: PITTSBURGH REGION: 1 NOTIFICATION TIME: 10:30[ET]
COUNTY: STATE: PA EVENT DATE: 02/20/95
LICENSE#: AGREEMENT: N EVENT TIME: 10:00
[EST]
DOCKET: LAST UPDATE DATE: 02/20/95
NOTIFICATIONS
NRC NOTIFIED BY: H SEPP
HQ OPS OFFICER: JOHN MacKINNON
EMERGENCY CLASS: NOT APPLICABLE
10 CFR SECTION:
CDEF 21.21(b)(2) DEFECTS/NONCOMPLIANCE
EVENT TEXT
THE FOLLOWING IS A PARTIAL TEXT OF A FACSIMILE FROM WESTINGHOUSE
ELECTRIC
CORPORATION, PITTSBURGH, PA. THIS PART 21 PERTAINS TO AN IDENTIFIED
PRESSURE REDUCING SLEEVE LOCKNUT DEFECT FOR JHF MODEL SAFETY
INJECTION
PUMP MANUFACTURED BY INGERSOLL DRESSER PUMP (IDP) COMPANY.
THIS FACSIMILE IS AN "UPDATE TO 10CFR21 REPORT CONTAINED IN
WESTINGHOUSE
LETTER NTD-NRC-94-4320, DATED 10/19/94 AND STATUS REPORT CONTAINED IN
WESTINGHOUSE LETTER NTD-NRC-94-4361, DATED 12/21/94.
REVIEW HAS BEEN COMPLETED AND INDICATES THAT SOME OF THE
ADDITIONAL PUMP
PARTS MAY ALSO CONSTITUTE A DEFECT, AS DEFINED IN 10CFR21, WHICH
COULD
CREATE A SUBSTANTIAL SAFETY HAZARD. IDP's EVALUATION RESULTS
INDICATE
THAT ALL 416 SS PARTS PROCESSED UNDER IDP HEAT NUMBERS # 15899 AND #
28144 ARE SUSCEPTIBLE TO THE SAME FAILURE MECHANISM AS THE PRESSURE
REDUCING SLEEVE LOCKNUTS."
THIS ELEVEN PART FACSIMILE CALLS OUT THE FOLLOWING REACTOR PLANTS
USING
PARTS FROM HEAT # 15899 & HEAT # 28144.
KANSAI OHI 1 & 2; TVA, WATTS BARR 1 & 2; DUKE POWER, MCGUIRE 1 & 2,
CATAWBA 1 & 2; COMMONWEALTH EDISON, BRAIDWOOD 1 & 2, BYRON 1 & 2,
WOLF
CREEK NUCLEAR OPERATING COMPANY, WOLF CREEK.
FOLLOWING REACTOR PLANTS COULD BE USING THE DEFECTIVE PARTS FROM
THE HEAT
NUMBERS LISTED ABOVE.
ALABAMA POWER, FARLEY 2, COMMONWEALTH EDISON, ZION 1,
CONSOLIDATED
EDISON, INDIAN POINT, DUQUESNE LIGHT, BEAVER VALLEY 1, INDIANA
MICHIGAN
POWER, COOK 2, KANSAI ELECTRIC, OHI 1 & 2, NORTHERN STATES POWER,
PRAIRE
ISLAND 1 & 2, PORTLAND GENERAL ELECTRIC, TROJAN, PACIFIC GAS &
ELECTRIC,
DIABLO CANYON 2, AND PUBLIC SERVICE ELECTRIC AND GAS, SALEM 1 & 2.
(Continued on next page)
LICENSEE: WESTINGHOUSE ELECTRIC PAGE # 2 OF EVENT NUMBER: 284
FACSIMILE SENT TO WALTER HAASS.
*** END OF DOCUMENT ***
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