IE Circular No. 79-19 - Loose Locking Device on Ingersoll-Rand Pumps
September 10, 1979
MEMORANDUM FOR: B. H. Grier, Director, Region I
J. P. O'Reilly, Director, Region II
J. G. Keppler, Director, Region III
K. V. Seyfrit, Director, Region IV
R. H. Engelken, Director, Region V
FROM: Norman C. Moseley, Director, Division of Reactor
Operations Inspection, IE
SUBJECT: IE CIRCULAR No. 79-19 - LOOSE LOCKING DEVICE ON
The subject Circular is transmitted for issuance on September 13, 1979. The
Circular should be issued to all power reactor operating facilities and all
utilities having a construction permit.
The text of the Circular and draft letter to the licensees and permit
holders are enclosed for this purpose.
Norman C. Moseley, Director
Division of Reactor Operations
Office of Inspection and Enforcement
1. Draft Transmittal Letter
2. IE Circular No. 79-19
CONTACT: H. A. Wilber, TP
(Draft transmittal letter for IE Circular No. 79-19, to each holder of an
Operating License or a Construction Permit.)
IE Circular No. 79-19
The enclosed IE Circular No. 79-19, is forwarded to you for information. No
written response is required. Should you have any questions related to your
understanding of this matter, please contact this office.
1. IE Circular No. 79-19
2. List of IE Circulars Issued
in the Last 6 Months
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
September 13, 1979 IE Circular No. 79-19
LOOSE LOCKING DEVICES ON INGERSOLL-RAND PUMP IMPELLERS
Description of Circumstances:
Three reports have been submitted to the NRC regarding the loosening of
locking devices on the impellers of pumps manufactured by the Ingersoll-Rand
The first report was submitted as a significant deficiency (10 CFR 50.55[e])
by Arkansas Power and Light Company in letters of March 17, 1978 and May 9,
1978. The licensee reported excessive noise and vibrations in both Low
Pressure Safety Injection (LPSI) pumps during the preoperational test
program on Unit 2 of Arkansas Nuclear One (ANO). It was discovered that the
washers, jam nut and cap nut used to retain the impellers were missing on
both pumps (Ingersoll-Rand Type 8X20WD). The licensee's corrective action
involved the installation of a tab washer. This corrective action was, also,
taken on the containment spray pumps (Ingersoll-Rand Type 6X23WD) because of
similarity of design.
The second report was submitted by Duke Power Company in a licensee event
report (LER 50-287/78-23) dated January 24, 1979. The symptoms were similar
to those observed at ANO Unit 2 in that high vibration was detected in a
reactor building spray pump (Ingersoll-Rand Type 4X11A) for Oconee Unit No.
3. The licensee found that the impeller had worked loose. The corrective
action included a revision to the maintenance procedure to specify torque
The third report was 10 CFR 21 Report No. 79-01 submitted by Portland
General Electric Co. on April 16, 1979. This report identified a deficiency
that may exist in the Trojan Nuclear Plant containment spray pumps
(Ingersoll-Rand Type 6X23WD) in that there is a potential for the impeller
lock nut to loosen. The potential deficiency was identified because of the
similarity of the containment spray pumps design to the residual heat
removal (RHR) pumps (Ingersoll-Rand Type 8X20WD) and the discovery of a
loose lock nut on an RHR pump during pump maintenance. The corrective action
was to provide a positive mechanical lock on the impeller nut.
Westinghouse Nuclear Service Division has issued a Technical Bulletin to
Westinghouse plant owners on loose lock nuts on Ingersoll-Rand Types W, WD,
and WDF pumps. Excerpts from that Technical Bulletin are in Enclosure No. 1.
Combustion Engineering, Inc. has, also, informed the NRC of their actions
relative to the same problem in a letter dated March 13, 1978; excerpts from
this letter are in Enclosure No. 2.
IE Circular No. 79-19 September 13, 1979
Page 2 of 2
Recommended Action for Licensee's Consideration
All holders of operating licenses and construction permits should be aware
of the potential deficiency described above. It is recommended that the
licensees review the pumps used or planned for use in safety related systems
at their facilities to determine if Ingersoll-Rand Types A, W, WD, WDF are
installed. If these pumps, or units with similar impeller locking systems,
are used, the licensees should determine that the impellers are presently
locked in an acceptable manner and that maintenance and installation
instructions provide adequate guidance to ensure that pump impellers are
securely locked in place.
No written response to this Circular is required. If you need additional
information regarding this subject, please contact the Director of the
appropriate NRC Regional Office.
Enclosure No. 1: Excerpt from Westinghouse NSD Technical Bulletin No.
Enclosure No. 2: Excerpt from Combustion Engineering Inc.
Letter to Nuclear Regulatory Commission, March 13, 1978
Enclosure No. 1
EXCERPT FROM WESTINGHOUSE NUCLEAR
SERVICE DIVISION TECHNICAL BULLETIN
No. NSD-TB-78-3 April 21, 1978
Several plants under construction have experienced a loosening of the
impeller lock-nut on the Ingersoll Rand RHR Pumps. The problem has occurred
during the initial startup of the pump or during flushing operations.
The possible causes for this lock nut becoming loose could include: running
the pumps in reverse rotation, improper torquing of the lock nut, or the
effects of foreign materials in the pumped fluids which could cause binding
of the impeller.
Westinghouse, in conjunction with the supplier, has developed retrofit kits.
These kits may be provided as an alternate method to further assure a more
positive locking mechanism than that originally furnished with the pump.
*Quantity & Model 8 X 20 W - (2) PNJ, PGE, PEG, AMP.
Quantity & Model 8 X 20 WD - (2) TVA, TEN, VGB, VRA, DAP, DBP, APR.
Quantity & Model 8 X 20 WDF - (2) WAT, WBT, CGE, CQL, CRL, CSL, CTL, NEU,
DMW, TBX, TCX, CAE, CBE, CCE, CDE, DCP,
DDP, NAH, NCH, LLP, LMP, GAE, GBE, PBJ,
Dr. Ernst Volgenau - 2 -
Millstone Unit II is currently shutdown for refueling and maintenance; the
earliest initial operation of either Waterford Unit 3 or San Onofre Units 2
and 3 pumps is expected in late 1979. In our opinion no condition currently
exists which adversely affects the health and safety of the public.
Arkansas Power and Light has committed to provide the Nuclear Regulatory
Commission a detailed report of the pump failures and their intended
corrective action. Combustion Engineering, in conjunction with
Ingersoll-Rand, is supporting that effort. Ingersoll-Rand has modification
kits available which provide a more positive locking design. Combustion
Engineering is recommending prompt installation of these modification kits
on ANO-2 and Millstone II. We are recommending to Louisiana Power and Light
and Southern California Edison that the modification kits be installed prior
to initial operation of their pumps.
Very truly yours,
COMBUSTION ENGINEERING, INC.
Enclosure No. 2
Excerpts from Combustion Engineering Inc.
Letter to the Nuclear Regulatory Commission
March 13, 1978
Dr. Ernest Volgenau, Director
Office of Inspection and Enforcement
U. S. Nuclear Regulatory Commission
Washington, D. C. 20555
Dear Dr. Volgenau:
This is to confirm my telephone conversation with Mr. Davis of your office
on March 10, 1978.
On February 17, 1978 Arkansas Power and Light reported to Mr. Jim Gagliardo,
NRC Region IV, the successive failures of the two Low Pressure Safety
Injection Pumps' impeller retaining parts at the initiation of shutdown
cooling during PreOperational testing at ANO-2. That report was made
pursuant to the provisions of 10 CFR 50.55(e).
Since that time, Combustion Engineering has investigated whether similarly
designed pumps (Ingersoll-Rand WD & WDF models) have been supplied by C-E to
other nuclear facilities. We have determined that four other Combustion
Engineering supplied Nuclear Steam Supply Systems have this type of impeller
locking system on their Ingersoll-Rand pumps and may be susceptible to this
type of failure. They are Northeast Utilities' Millstone Unit II, Louisiana
Power and Light's Waterford Unit 3 and Southern California Edison's San
Onofre Units 2 and 3.
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