ML17331A426
| ML17331A426 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 08/06/1980 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Dolan J INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| Shared Package | |
| ML17319A548 | List: |
| References | |
| NUDOCS 8008270091 | |
| Download: ML17331A426 (6) | |
Text
AUGUST Docket Nos.
5 and
-31 6 Sincerely, DISTRIBUTION 5
an 0-31 NRC PDRs (2)
Local PDR TERA NISC NRR Reading ORBl Reading B. Eieenhut Nr. John Dolan, Vice Presfdent Indiana and Hfchfgan Electric Company Post Office Box 18 Bowling Green Statfon C. Parrish
(
New York, Neo York 10004
Dear Hr. Dolan:
J. Olshinski J. Heltemes tte have completed our evaluation of the potential for pipe cracks forming fn the chemical and volume control systems (CVCS) due to excessfve charging pumps vibrations fn Donald C. Cook Unit Hos.
1 and 2.
Our revfetII was based on the fnformatfon provfded by Indfana and Michigan Electrfc Company fn letters dated August 8, 1979, October 29, 1979 and Hay 22, 1980.
He have determfned that the fnstal'latfon of the dampeners on the recfpro-catfng charging pump discharge flanges fn Unit Nos.
1 and 2.will reduce pipe efbratfons to levels at whfch we do not expect pipe crahks could be developed.
A copy of our evaluatfon fs enclosed for your fnformatfon.
Enclosure:
Safety Evaluation cc:
w/enclosure See next page Steven A. Yarga, Chfef Operating Reactors Branch 01 Division of Lfcensfng
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UNITED STATES t
NUCLEAR REGULATORY COMMISSION WASHINGTON, O. C. 20555 August 6, 1980 Docket Nos.
50-315 and 50-316 Hr. John Dolan, Vice President
.'ndiana and Michigan Electric Company Post Office Box 18 Bowling Green Station New York, New York 10004 Oear Hr. Dolan:
We have completed our evaluation of the potential for pipe cracks forming in the chemical and volume control systems (CVCS) due to excessive charging pumps vibrations in Donald C.
Cook Unit Nos.
1 and 2.
Our review was based on the information provided by Indiana and Michigan Electric Company in letters dated August 8, 1979, October 29, 1979 and May 22, 1980.
We have determined that the installation of the dampeners on the recipro-cating charging pump discharge flanges in Unit Nos.
1 and 2 will reduce pi pe vibrations to levels at which we do not expect pipe cracks could be developed.
A copy of our evaluation is enclosed. for your information.
Sincerely,
)!
e<e. <
Operating Reactors ch 41 Division of Licensing
Enclosure:
Safety Evaluation cc:
w/enclosure See next page
Mr. John Dolan Indiana and Michigan Electric Company Page 2
CC:
Hr. Robert W. Jurgensen Chief Nuclear Engineer American Electric Power Service Corporation 2 Broadway New York, New York 10004 Gerald Charnoff, Esquire
- Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.W.
Washington, D.
C.
20036 Citizens for a Better Environment 59 East Van Buren Street Chicago, Illinois 60605 Haude Preston Palenske Memorial Library 500 Market Street St. Joseph, Michigan 49085 Hr. D. Shaller, Plant Manager Donald C.
Cook Nuclear Plant P. 0.
Box 458
~
Bridgman,.Michigan 49106 Hr. Robert Masse Resident Inspector Donald C.
Cook Nuclear Plant U. S. Nuclear Regulatory Commission P. 0.
Box 458
- Bridgman, Michigan 49106 William J.
- Scanlon, Esquire 2034 Pauline Boulevard Ann Arbor, Michigan 48103
Enclosure DONALD C.
COOK NUCLEAR PLANT UNIT NOS.
1 AND 2 CVCS PUMP VIBRATIONS SAFETY EVALUATION REPORT Introduction Vibrations induced by the operation of positive displacement pumps have been identified as one source that will cause fatigue failure in system piping.
On May 18,
- 1978, NRC requested information on "pipe cracks in chemical volume control system (CVCS) due to excess~vmcharging pump vibrations" from Indiana and Michigan 'Power Company with respect to Donald C.
Cook Units 1
and 2.
The requested information was provided in letters dated August 8, 1979, October 29, 1979, and May 22, 1980.
Descri tion Donald C.
Cook Nuclear Plant Units 1
and 2 have similar CVCS arrangements.
They each employed two centrifugal charging pumps and one reciprocating
{positive displacement) charging pump A General Atomic Company PDSN 3-200 model dampener was installed on the discharge flange of the Unit 2 reciprocating charging pump during the fall of 1979 refueling outage.
Another dampener of -the. same model will be installed in Unit 1 during the upcoming refueling outage.
The performance of these positive displacement metering pumps was calibrated by several tests.
Evaluation and Conclusion The reci procating charging pumps preoperational test showed that their usage did not induce excessive vibrations in the CVCS of either unit, however, operating experience indicated that control system responses were affected by the discharge pressure fluctuations.
Therefore, the licensee decided to install a dampener on the pump discharge flange to smooth out the pressure pulsations.
The Unit 2 dampener was installed during the fall of 1979 refueling outage.
Tests were conducted by an independent consultant before and after the dampener was installed in Unit 2.
Pressure transducers were attached at the'pump suction, the pump cylinder head, between the pump discharge and the dampener, and downstream of the dampener.
Data were taken at various pump speeds.
The results showed that the maximum pressure pulsa-tion downstream of the dampener was 3.4X of the normal operating pressure at the maximum pump speed.
The operation of the reciprocating charging pumps with dampeners on the pumps discharge did not induce excessive vibrations.
A fluctuation of 3.4X stress in the system will yield an alternate stress corresponding to negligible usage factor.
We therefore do not expect that pipe cracks will develop in the CYCS system of Unit 2 due to reciprocating charging pump operation.
Similarly, because the same type and model of dampener will also be installed on the discharge flange of the reciprocating charging pump in Unit, 1 during the current refueling outage, we do not expect that cracks will develop in the CVCS system of Unit 1
due to reciprocating charging pump operation.