ML090540485
| ML090540485 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 02/20/2009 |
| From: | - No Known Affiliation |
| To: | Division of License Renewal |
| References | |
| Download: ML090540485 (7) | |
Text
PrairieIslandNPEm Resource From: Eckholt, Gene F. [Gene.Eckholt@xenuclear.com]
Sent: Friday, February 20, 2009 7:28 PM To: Richard Plasse Cc: Vincent, Robert; Travers, Greg
Subject:
Summary of 2/10/09 Telecon Attachments: Summary of 2-10-09 conference Call with NRC - Final.doc Rick Here is our summary of the 2/10/09 telecon Gene Eckholt Project Manager License Renewal Project Prairie Island Nuclear Generating Plant Phone: 651-388-1121 ext. 4137
<<Summary of 2-10-09 conference Call with NRC - Final.doc>>
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Hearing Identifier: Prairie_Island_NonPublic Email Number: 744 Mail Envelope Properties (7A9B2084CC9CEC45828E829CBF20D638033F6AE5)
Subject:
Summary of 2/10/09 Telecon Sent Date: 2/20/2009 7:28:18 PM Received Date: 2/20/2009 7:28:05 PM From: Eckholt, Gene F.
Created By: Gene.Eckholt@xenuclear.com Recipients:
"Vincent, Robert" <Robert.Vincent@xenuclear.com>
Tracking Status: None "Travers, Greg" <Greg.Travers@xenuclear.com>
Tracking Status: None "Richard Plasse" <Richard.Plasse@nrc.gov>
Tracking Status: None Post Office: enex02.ft.nmcco.net Files Size Date & Time MESSAGE 256 2/20/2009 7:28:05 PM Summary of 2-10-09 conference Call with NRC - Final.doc 49728 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
Recipients Received:
Summary of 2/10/09 NRC - PINGP License Renewal Conference Call NRC Attendees: Rick Plasse, Jim Medoff, Jim Davis, Wayne Pavinich, Mr. Yang, On Yee, Bob Jackson PINGP Attendees: Gene Eckholt, Phil Lindberg, Bill O'Brien, Bill Roman, Dennis Davis, Lora Drenth, Mark Rinckel, Bob Vincent Summary: The purpose of the call was to discuss several follow up questions and some draft RAIs. One RAI will be issued and a supplemental letter is also desired from PINGP with any clarifications determined to be needed. Specific issues discussed are as follows:
Drawing questions Follow-up questions on drawings (2.3.4.5 and 2.3.4.6) were discussed. PINGP understands the questions and agreed to provide clarification in a supplemental letter. RAIs will not be issued.
Boric Acid Corrosion Program Follow up questions NRC observed that the response provided in the 2/6/09 letter was acceptable for safety-related components, but wanted more information on treatment of boric acid leakage from non-safety related components in the vicinity of safety related components.
PINGP explained that the program does not differentiate between safety related and non-safety related components for the identification and cleanup of boric acid, and associated corrosion evaluations. The RAI response applies to all components affected by boric acid leakage and not just safety related components.
The reviewer explained that he wanted to assure that boric acid gets cleaned up promptly. PINGP explained that RAI responses describe the plant's response.
Boric acid leakage discovered inside containment during an outage would be cleaned up before startup from that outage.
The reviewer also questioned OE related to another plant related to leakage of borated water through sand pit covers, and wondered how the covers were addressed at PINGP. PINGP confirmed that the covers were in-scope for LR and managed for aging as a subassembly of the refueling pool liner.
The reviewer indicated he would re-review the RAI responses and see if he has any additional questions. No further action is needed from PINGP.
Management of Cracking in CASS Components NRC raised questions about the UT examination method described in the RAI response. There is no qualified UT technique which can reliably detect cracking 1
in CASS. At present, only an enhanced visual examination will suffice until a qualified UT technique becomes available. It was also stressed by the NRC that the Risk Informed - ISI Program should not be credited, and that the ASME code requirements should be followed for CASS components.
PINGP understands the question, agreed to consider a commitment to enhanced visual examinations for CASS, and will provide a clarification to the RAI response in a supplemental letter. An RAI will not be issued.
Inspection of Internal Surfaces Program The GALL program provides for inspections on a periodic basis, but the PINGP LRA and RAI responses indicate that inspections will be performed on components when disassembled for maintenance or surveillance. There is no assurance that components will be examined periodically. Components that are not scheduled for periodic maintenance would not be inspected on a recurring basis.
PINGP responded that this program is a new program and, as stated in the LRA, will be consistent with GALL. PINGP does have a PM program to manage periodic maintenance activities, and intends to look at certain components periodically as the GALL program indicates.
NRC will review the GALL wording to confirm it adequately indicates that inspections under the program will be performed periodically. No further action is needed from PINGP.
UT Technique for Steam Generator Shell NRC requested more details on how the plant addressed the UT limitations for examination of shell-to-transition cone welds in the Model 51 steam generators.
PINGP explained that the ISI program has been augmented to require visual examination of the welds from the inside of the steam generators. UT examinations are performed also, but the techniques in use by the plant have not had to be modified to address the issues identified in IN 90-04.
NRC will address issue in the SER by indicating that visual examination is used to augment code requirements for these welds. No further action is needed from PINGP.
Fuel Oil analysis Program The LRA and RAI responses indicate a number of exceptions to the GALL related to biological contamination. Oil samples are not analyzed for biological activity, no biocides are added to oil as a preventive measure, and no periodic tank internal inspections are performed to look for corrosion. Together, there is no monitoring for biological activity. NRC can accept these exceptions, however, PINGP needs to clarify what test (i.e., ASTM standard) is performed that would 2
identify biological activity. In addition some question was raised about the use of ASTM D975 in lieu of the standards identified in GALL.
PINGP agreed to clarify the RAI responses to indicate that particulate testing and water/sediment testing would be expected to identify algae or biological activity if present. It was also agreed to clarify that ASTM D975 is used for the overall program requirements under Tech Specs, but the other standards identified in GALL (e.g., D1796 and D6217) are used by PINGP for the actual analysis methodology. This clarification will be provided in a supplemental letter. An RAI will not be issued.
Closed Cycle Cooling Water Exception The NRC noted that the new exception identified in the 2/6/09 letter indicated that no performance testing is conducted on three chiller loops, and it appeared that aging management of these loops is only being performed with water chemistry control under the CCCW program. This is not sufficient to tell whether any aging is occurring.
PINGP confirmed that performance monitoring is not being conducted because there is not adequate instrumentation on these loops. PINGP agreed to modify the exception to clarify that visual inspections will be performed in the three affected chiller loops to look for aging-related degradation. This clarification will be provided in a supplemental letter. An RAI will not be issued.
Non-Regenerative Heat Exchanger Cracking NRC indicated that use of Water Chemistry and One-Time Inspection for management of SCC is acceptable. However, the aging effect/mechanism of cracking due to cyclic loading in GALL would not be managed by these programs. The RAI dispositions cyclic loading by reference to a TLAA, but there is not a full analysis of fatigue in heat exchanger tubes, so the aging effect is not really being managed as a TLAA. One-time inspection of other components of the same materials and environment would not be representative of the unique cyclic loading experienced in the heat exchanger.
PINGP explained that non-regenerative heat exchangers (Letdown and Excess Letdown Heat Exchangers) are not exposed to significant thermal cycling. The Letdown HX is normally in service continuously in essentially a steady state condition during plant operation, and not subject to thermal cycling other than during startups and shutdowns. Taking charging and letdown out of service is a rare event. The Excess Letdown HX is normally not in service. The TLAA discussion related to the exemption from fatigue evaluation for these HXs considers both mechanical and thermal cycling, and really indicates that fatigue evaluation is not needed because the endurance limit of the HXs would not be reached.
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NRC stated that RAI responses do not indicate that cyclic loading is not applicable - they just point to Water chemistry, OTI, and a TLAA for management. NRC needs a discussion that shows that cyclic loading is really not applicable to these heat exchangers. This discussion should address both thermal cycling and mechanical cycling.
PINGP agreed to clarify the RAI response to indicate that cyclic loading leading to fatigue cracking is really not an aging mechanism of concern for these HXs.
This clarification will be provided in a supplemental letter. An RAI will not be issued.
Draft RAI 4.3.1.4-1 Response re: Unit 2 Primary Inlet Nozzle Fatigue Usage Clarification was requested for the wording "worst case normal and upset loading conditions" and the value of 24,000 cycles.
PINGP explained that the worst case transient (Loss of Flow) was selected from the set of normal design transients, and then very conservatively assumed to be imposed 24,000 times. 24,000 is an approximate total number of all design cycles assumed for the RCS design.
It was also questioned whether OBE was addressed in the PINGP fatigue calculations. PINGP confirmed that OBE was considered.
The inspector had no further questions. No further action is needed from PINGP.
Draft RAI 4.3.1-1 re: Procedure for Tracking Transient Cycles NRC requested a description of how cycles are tracked to confirm that both numbers and severity of transients are verified to be within design assumptions.
It was also questioned whether PINGP had a complete accounting of cycles, or if some had to be reconstructed or estimated. A histogram showing plant startup/shutdown cycles was also requested.
PINGP confirmed that cycle counts for all design transients are documented in SP 1173 [2173]. A history of all transients dating back to initial operation is logged in the SP. It was also discussed that transient severity (e.g., PZR surge line stratification events) are compared to design limits (e.g., RCS Hot Leg - to -
PZR delta T).
NRC indicated that this information needed to be docketed. This question will be issued as a formal RAI.
Draft RAI 4.3.3-3 Fen for Stainless Steel in RHR Class 1 Piping Tee LRA Table 4.3-8 in the last row shows Fen to be 2.55. Explain why this is the bounding value since Fen can be as high as 15.35.
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PINGP explained that the RHR system operates at 350oF, which is less than 200oC. This is discussed in USAR 10.2.4.2. Therefore the applicable Fen is 2.55.
NRC will review the USAR section and use it for reference. No further action is needed from PINGP.
LRA Section 3.1.2.2.13 This Further Evaluation section says it addresses nickel alloy in reactor internals, but the section is intended to address all nickel alloy in the RCS. Internals are addressed in 3.1.2.2.15 and 17. Correction or clarification is needed.
PINGP agreed to clarify the section to address the appropriate components.
This clarification will be provided in a supplemental letter. An RAI will not be issued.
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