ML18053A510
| ML18053A510 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 08/19/1988 |
| From: | Elbert P CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML18053A509 | List: |
| References | |
| NUDOCS 8808240086 | |
| Download: ML18053A510 (5) | |
Text
CONSUMERS POWER COMPANY Docket 50-255 Request for Change to the Technical Specifications License DPR-20 For the reasons hereinafter set forth, it is requested that the Technical Specifications contained in the Provisional Operating License DPR-20, Docket 50-255, issued to Consumers Power Company on October 16, 1972, for the Palisades Plant be changed as described in Section I below:
I. Changes A.
In Table 4.3.2, item 2. add footnote 4 to "Frequency" to read:
4
" Primary coolant Pump Upper Flywheel Volumetric 100% examination is waived for the 1988 Refueling Outage."
II. Discussion This proposed change is a one time exemption from the requirement of Technical Specification Table 4.3.2, Item 2.
This requirement calls for a 100 percent volumetric examination of the upper flywheel of each primary coolant pump at a maximum interval of each refueling outage.
The testing interval required by the Technical Specifications exceeds the inspection requirements of STS, Section 4.4.11 and Regulatory Position C.4b of Regulatory Guide 1.14.
Regulatory Guide 1.14 C.4.b(l) and (2) state the following:
- 1.
An in-place ultrasonic volumetric examination of the areas of higher stress concentration at the bore and keyway at approximately three year intervals, during the refueling or maintenance shutdown coinciding with the inservice inspection schedule as required by Section XI of the ASME Code.
- 2.
A surface examination of all exposed surfaces and complete ultrasonic volumetric examination at approximately ten year intervals, during the plant shutdown coinciding with the inservice inspection schedule, as required by Section XI of the ASME Code.
Consumers Power Company believes the inservice testing requirements imposed by Technical Specification Table 4.3.2, Item 2 are excessive based on the following:
- 1.
The construction of the Palisades flywheels meets the Charpy V-notch and fracture toughness requirements of RG 1.14 as documented by
(
8808240086. 880819
, I \\
PDR ADOCK. 05000255.. '\\'..)
P PNU I
- t.
OC0888-0099A-NL04
2 paragraph V.A of NRC letter dated February 2, 1982.
The letter specifies that "although the NDT is 40°F rather than 10°F, the operating temperature of 100°F is still 60°F above NDT.
This margin above NDT coupled with a CVN energy at 70°F that far exceeds the 50 ft-lbs. required by the Regulatory Guide ensures that brittle fracture is unlikely and that a large tolerance to flaw-induced fracture exists.
This flaw tolerance and operation in a temperature region where the potential for brittle fracture is reduced meets the intent of Regulatory Guide 1.14 although one specific requirement of the guide has not been met".
- 2.
There has never been a reported failure of a primary coolant pump flywheel as documented by NRC letter dated February 2, 1982 and a review of NPRDS data conducted by Consumers Power Company dated October 19, 1987.
- 3.
The last acceptability of the present Palisades flywheels, is documented by successful passing of examination procedure C-E CPCO-ISI-012, Revision 0 performed on the Palisades flywheels between the dates of December 1985 and February 1986.
This procedure is the most recent documentation of the acceptability of Palisades flywheels.
Since the preoperational examination conducted by Southwest Research Institute in 1970, the Palisades flywheels have been examined an additional seven times by three different organizations.
Each set of test results shows no detectable degradation to the flywheels has occurred.
Palisades is requesting a one time exemption from Technical Specification Table 4.3.2, Item 2 based on the discussion above.
Furthermore, Palisades has met and exceeded the test interval requirements of RG 1.14.
Consistent with the Regulatory Guide, the next required examination would occur during our 1990 Refueling Outage.
III. Analysis of No Significant Hazards-Consideration The probability of an accident previously evaluated in the FSAR is not increased.
FSAR 5.5.3.1, "Containment Missiles" states "missiles which could only be generated by a massive, rapid failure of the primary coolant system components (reactor vessel, pressurizer, primary coolant pump casings and driver) were not considered credible." This position is justified based upon material characteristics, inspections, quality control during fabrication and copservative design.
The inspections referred -to in-FSAR 5.5.3.1 and -Technical Specification Table 4.3.2 are documented in SEP Topic III-10.B, "Pump Flywheel Integrity", NRC letter dated February 2, 1982.
From subsection V.C, this document requires the following:
OC0888-0099A-NL04
- 1.
One hundred percent UT baseline inspection of the upper 72 inch flywheels including the disc shaft interface.
3
- 2.
One hundred percent UT inservice inspection of the upper 72 inch flywheels, including disc shaft interface at each refueling shutdown (about every 19 months).
- 3.
A visual inspection to the extent practical, using optical means to provide interior access where required of all three flywheels in each motor each time UT inspections of the upper flywheels are performed.
Palisades believes these requirements are excessive and do not significantly reduce the probability of an accident based on the following observations:
- 1.
Paragraphs V.A and V.B of SEP Topic III-10.B "Flywheel Integrity",
dated February 2, 1982 documents the material requirements necessary to prohibit brittle fracture and ductile rupture and concludes even though one specific requirement of the guide (NDT) has not been met, the intent of Regulatory Guide 1.14 is met by the Palisades flywheels.
- 2.
Paragraph V.C of this report documents that, as of Inservice Inspection Number 6 conducted during the period of September 8, 1979 to May 28, 1980, no deterioration had been found in the upper flywheel.
- 3.
Paragraph V.C also states industry experience with motor flywheel combinations similar in design to Palisades units has been very favorable.
No flywheel failure or other associated.flywheel problem has ever been experienced with this type of design.
Additionally, the following observations are also made:
- 1.
Testing performed from 1970 to February 1986, a total of 8 tests over an 18 year period continues to show no upper flywheel degradation.
- 2.
A Plant review of NPRDS conducted on October 19, 1987 revealed zero PCP flywheel failure reports to that date.
Therefore, it is conclu9ed the increased test frequency of Technical Specification Table 4.3.2, Item 2 over RG 1.14 does not significantly reduce* the probability of an accident as evaluated in the FSAR.
OC0888-0099A-NL04
4 The cons~quences of an accident previously evaluated in the FSAR are not increased.
As stated above, Palisades had no detectable deterioration in the upper flywheels through the February 1986 inspection.
This fact is independent of the test interval. Therefore, the probability or consequences of an accident evaluated in the FSAR are not increased by lengthening or d~laying the test interval. It should be noted here that Palisades intends to delay the test interval only until the 1990 Refueling Outage.
The probability of a malfunction of equipment important to safety is not increased.
As stated before, there has been no detectable deterioration in the upper flywheels to the time of the most recent inspection (Procedure CPCO-ISI-012 Revision 0, December 1985 through February 1986).
The increased test frequency of Technical Specification Table 4.3.2, Item 2 has provided no increased assurance of flywheel integrity over the RG 1.14 requirements.
Since the flywheels also meet the material requirements of RG 1.14 as stated above, the probability of a malfunction of equipment important to safety is not increased.
The consequences of a malfunction of equipment important to safety is not increased.
As stated previously in this safety evaluation, the increased examination interval has not provided any additional assurance of flywheel integrity over RG 1.14. Therefore, this one time exemption will not increase the consequences of any malfunction.
The possibility of a different type of accident from any evaluated in the FSAR is not created by this waiver request~ This one time exemption has no effect on the LOCA analysis or loss of coolant flow analysis of FSAR Chapter 14.
The possibility of a malfunction of a different type than any evaluated in the FSAR is not created.
The modes of failure for a flywheel is either by brittle fracture or ductile rupture caused by unit overspeed.
These types of failures and their cause are independent of the examination interval and this waiver request.
The margins of safety defined for Technical Specifications Table 4.3.2 Item 2 are reduced slightly by this request for waiver.
The absolute margin of safety is probably reduced by this request.
However, based on the answers to the previous six questions, Palisades believes the reduction is small enough to be insignificant.
III.
Conclusion The Palisades Plant Review Committee has reviewed this Technical Specification Change Request and has determined that this request does not involve an unreviewed safety question, and, therefore involves no OC0888-0099A-NL04
5 significant hazards consideration.
This change has also been reviewed under the cognizance of the Nuclear Safety Board.
A copy of this Technical Specification Change Request has been sent to the State of Michigan official designated to receive such Amendments to the Operating License.
CONSUMERS POWER COMPANY B~~kr-UiAEibert, Vice President Fossil and Hydro Operations Sworn and subscribed to before me this 19th day of August 1988.
~/~
Linda L Bumb, Notary Public Jackson County, Michigan My commission expires September 16, 1989
-~
~
- .,_ - (,
'. -,: \\.'
OC0888-0099A-NL04