ML021050154
| ML021050154 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/29/2002 |
| From: | Cooper D Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| IEB-01-001 | |
| Download: ML021050154 (6) | |
Text
NMC Committed to Nuclear Excellence Palisades Nuclear Plant Operated by Nuclear Management Company, LLC March 29, 2002 10 CFR 50.54(f)
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 DOCKET 50-255 - LICENSE DPR PALISADES NUCLEAR PLANT NRC BULLETIN 2001-01: CIRCUMFERENTIAL CRACKING OF REACTOR PRESSURE VESSEL HEAD PENTRATION NOZZLES - UPDATED RESPONSE On August 3, 2001, the Nuclear Regulatory Commission transmitted Bulletin (BL) 2001-01, "Circumferential Cracking of Reactor Pressure Vessel Head Penetration Nozzles." Nuclear Management Company (NMC), LLC responded to BL 2001-01 for Palisades on August 31, 2001.
NMC recently reevaluated the Palisades reactor head temperature. As a result, Palisades is being re-categorized into the five to thirty year susceptibility group, with 22.5 effective full power years calculated from March 2001 until the Oconee 3 condition. Therefore, NMC is providing an updated response to items 1.a, 1.d, 3, 4, 5, and the Reference section. The updated response is attached. The original enclosure attachments remain unchanged and, therefore, are not included.
SUMMARY
OF COMMITMENTS This letter contains one new commitment and no revisions to existing commitments.
NMC will perform a 100% effective visual examination of the reactor vessel head upper metal surface for the Palisades Plant in accordance with BL 2001-01 during tnexf eli g outage.
Douglas E. Cooper Site Vice-President, Palisades CC Regional Administrator, USNRC, Region Ill Project Manager, USNRC, NRR NRC Resident Inspector - Palisades Enclosure 27780 Blue Star Memorial Highway
- Covert, MI 49043 Telephone: 616.764.2000
NUCLEAR MANAGEMENT COMPANY, LLC PALISADES NUCLEAR PLANT DOCKET 50-255 NRC BULLETIN 2001-01: CIRCUMFERENTIAL CRACKING OF REACTOR PRESSURE VESSEL HEAD PENETRATION NOZZLES PALISADES PLANT UPDATED RESPONSE To the best of my knowledge, the content of this updated response to NRC Bulletin 2001-01, "Circumferential Cracking of Reactor Pressure Vessel Head Penetration Nozzles" is truthful and complete.
By__ý Daniel J. Mal6ne Plant Manager, Palisades Sworn and subscribed to before me this _
7_ day of 2002.
Nora Jean'-Fler, Notary Public Van Buren County, Michigan My commission expires May 14, 2002 (Seal)
ENCLOSURE NUCLEAR MANAGEMENT COMPANY, LLC PALISADES NUCLEAR PLANT DOCKET 50-255 March 2002 NRC BULLETIN 2001-01: PALISADES PLANT UPDATED RESPONSE Three Pages Follow
NRC BULLETIN 2001-01: CIRCUMFERENTIAL CRACKING OF REACTOR VESSEL HEAD PENETRATION NOZZLES PALISADES PLANT UPDATED RESPONSE Requested Background and Descriptive Information
- a.
Plant Specific PWSCC Susceptibility Ranking Palisades Nuclear Plant was originally ranked for the potential for primary water stress corrosion cracking (PWSCC) of the reactor pressure vessel (RPV) top head nozzles using the time-at-temperature model and plant specific input data reported in MRP-48 [1]. Nuclear Management Company (NMC), LLC re-evaluated the Palisades reactor head temperature in 2002.
The re-evaluation results in Palisades being re-categorized into the five to thirty year susceptibility group, with 22.5 effective full power years (EFPYs) of additional operation from March 1, 2001, until reaching the same time at temperature that Oconee Nuclear Station Unit 3 (ONS3) had at the time that its leaking nozzles were discovered in February 2001 [2].
Using the criteria stated in Nuclear Regulatory Commission (NRC)Bulletin 2001-01, Palisades NuclearPlant falls into the NRC category of plants considered to have a moderate susceptibility to PWSCC of the RPV top head nozzles.
- b.
Description of Vessel Head Penetration (VHP) Nozzles Palisades Nuclear Plant has 54 total RPV head nozzles including 45 CRDM nozzles, 8 incore instrument (ICI) nozzles, and one vent nozzle. The vent nozzle is located near the center of the reactor head, at a center-to-center distance of 11.98 inches from the nearest CRDM. The CRDM, ICI and vent nozzles are made of SB-167 Alloy 600. Additional requested nozzle information is provided in Table 2-3 of MRP-48 [1].
- c.
Description of Reactor Pressure Vessel (RPV) Head Insulation As reported in Table 2-1 of MRP-48 [1], Palisades Nuclear Plant has blanket contoured RPV head insulation.
Two layers of blanket insulation strips rest upon the reactor head at right angles to each other, beneath a stainless steel cover assembly. The hinged, latched covers are removable. The blankets can be removed and re installed or replaced. An attached photograph depicts the reactor head area with some covers removed.. (Attachment 1)
Page 1
NRC BULLETIN 2001-01: CIRCUMFERENTIAL CRACKING OF REACTOR VESSEL HEAD PENETRATION NOZZLES PALISADES PLANT UPDATED RESPONSE
- d.
Description of RPV Head and Nozzle Inspections Within Past Four Years As reported in Table 2-1 of MRP-48 [1], Palisades Nuclear Plant has performed visual inspections of the reactor top head area for leaks per the current Generic Letter 88-05 leakage detection program, but no additional RPV head and nozzle inspections have been conducted within the past four years (as of August 31, 2001).
- e.
Description of the Configuration of Equipment and Cables on Top of the Reactor Pressure Vessel Head A description of the configuration of equipment and cables on the vessel head is attached to this response. (Attachment 2)
- 2.
Previously Experienced Leakage From or Cracking in VHP Nozzles Palisades Nuclear Plant has not experienced leakage or cracking in VHP nozzles.
No further response to this question is required.
- 3.
Plans for Future Inspections - If Susceptibility Ranking Is Within 5 EFPY of ONS3 The susceptibility ranking for Palisades Nuclear Plant is not within 5 EFPY of ONS3. No further response to this question is required.
- 4.
Plans for Future Inspections - If Susceptibility Ranking Is Greater Than 5 EFPY and Less Than 30 EFPY of ONS3 NMC will perform a 100% effective visual examination of the reactor head upper metal surface during the next refueling outage. Qualification requirements will be to the 1989 Edition of American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section Xl. The acceptance criterion will be zero leakage from the reactor head and penetration nozzles.
The bases for concluding that regulatory requirements are met are discussed in MRP-48 [1].
If leakage is detected, it will be investigated and repaired as needed, in accordance with the current NMC repair/replacement program at Palisades including applicable codes and standards. Any indication of leakage or cracks will be evaluated and characterized using a combination of surface and/or volumetric examinations.
Page 2
NRC BULLETIN 2001-01: CIRCUMFERENTIAL CRACKING OF REACTOR VESSEL HEAD PENETRATION NOZZLES PALISADES PLANT UPDATED RESPONSE
- 5.
Reporting of Future Inspection Results Palisades Nuclear Plant will provide the information requested in Item 5 of NRC Bulletin 2001-01, or indicate that no leakage was identified, within 30 days after plant restart following the next refueling outage.
During the next refueling outage, NMC will perform a 100% effective visual examination of the Palisades reactor vessel head upper metal surface in accordance with BL 2001-01.
References
- 1.
PWR Materials Reliability Program Response to NRC Bulletin 2001-01 (MRP-48), EPRI, Palo Alto, CA: 2001. TP-1 006284.
- 2.
EA-C-PAL-01-03348-01, Re.v. 1.
Attachments, Photograph of Palisades Reactor Vessel Head Insulation, Configuration of Equipment and Cables on the RPV Head Page 3