ML18066A329
| ML18066A329 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 11/10/1998 |
| From: | Haas K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-98-04, GL-98-4, NUDOCS 9811180163 | |
| Download: ML18066A329 (15) | |
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A CMS Energy Company November 10, 1998 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555 Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, Ml 49043 DOCKET 50-255 - LICENSE DPR PALISADES PLANT 120-DAY RESPONSE TO GENERIC LETIER (GL) 98-04 "POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT" On July 14, 1998, NRC issued Generic Letter (GL) 98-04, entitled, "Potential For Degradation of The Emergency Core Cooling System and The Containment Spray System, After a Loss-Of-Coolant Accident Because of Construction and Protective Coating Deficiencies and Foreign Material In Containment". This generic letter requires, within 120 days of the date of the letter, submittal of a written description of plant programs for ensuring that Service Level 1 protective coatings inside of the I
containment would not fail during a design basis Loss Of Coolant Accident ( LOCA) in a
/
manner that would impair the operation of the Emergency Core Cooling System
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(ECCS) and Containment Spray System (CSS).
The attachment to this letter provides the Consumers Energy Company response for f1.,hori the Palisades Plant.
r \\ r DI
SUMMARY
of COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.
I Kurt M. Haas Director, Engineering CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades Attachment 2
CONSUMERS ENERGY COMPANY To the best of my knowledge, the contents of this response providing requested information per Generic Letter 98-04, are truthful and complete.
By I Kurt M. Haas Director, Engineering Sworn and subscribed to before me this
/ 0 #1 Day of ~
1998
~~~
Mary Ann Engle, Notary Public Berrien County, Michigan (Acting in Van Buren County, Michigan)
My commission expires February 16, 2000 SEAL
ATTACHMENT CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT 11 Pages
120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT NRC REQUEST (1)
A summary description of the plant-specific program or programs implemented to ensure that Service Level 1 protective coatings used inside the containment are procured, applied, and maintained in compliance with applicable regulatory requirements and the plant-specific licensing basis for the facility. Include a discussion of how the plant specific program meets the criteria of 10 CFR Part 50, Appendix B, as well as information regarding any applicable standards, plant specific procedures, or other guidance used for: (a) controlling the procurement of coatings and paints used at the facility, (b) the qualification testing of protective coatings, and (c) surface preparation, application, surveillance, and maintenance activities for protective coatings. Maintenance activities involve reworking degraded coatings, removing degraded coatings to sound coatings, correctly preparing the surfaces, applying new coatings, and verifying the quality of the coatings.
CONSUMERS ENERGY RESPONSE.
(1)
Licensing History of Issue The Palisades Plant construction license was granted in March of 1967. Generic regulatory requirements relevant to the emergency core cooling system (ECCS) or containment spray system (CSS) strainer blockage issue were first issued in 1971. 10 CFR Part 50, Appendix A General Design Criteria (GDC) were originally issued in February, 1971. Facilities with construction permits issued prior to this date are commonly referred to as "pre-GDC" plants, and their licensing basis is established by the facility Final Safety Analysis Report, the NRC Safety Evaluation Report, and commitments the licensee has made subsequently on the docket.
The original Palisades FSAR dated January 12, 1970, describes the design of the coating systems inside containment as follows:
The paint systems used on large surface area equipment inside of containment were selected on the basis of withstanding the post-maximum hypothetical accident (MHA) LOCA environment condition of 283 °F, 55 psig, 100 percent relative humidity, borated water, an integrated dose of 2 x 107 rads, and suitable heat transfer to the heat sinks. To meet these 1
120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT requirements, the primary paint system selected was a Carboline Co.
inorganic zinc system, Carbo Zinc 11 primer and inorganic zinc finish No.
3912. Inorganic zinc paint systems have been tested as follows:
(1) Irradiated at 2. 6 x 106 Rlhr to a cumulative dose up to 1 x 1010 R as covered by ORNL Report No. 3916 and ORNL report No. 3589. The conclusions based on the results of the irradiation are that the inorganic zinc paint systems will withstand the post-MHA radiation.
(2) Subjected to 44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br /> test with samples submerged in a solution at 212°F, 1.3 percent H3803 and 9.5 pH. Conclusions derived from the ORNL test data are that the inorganic zinc systems will withstand the post-MHA condition with negligible hydrogen production.
(3) Subjected to manufacturer's test with samples submerged in a solution of
- 9. 5 pH with the temperature varied as follows:
15D°F to 285°F in 4 Hours 285°F Held for 3 Hours 285°F to 20D°F in 2 Hours From the test results, the manufacturer has reported no significant physical changes in the paint system. Decontaminable coatings of the generic epoxy and phenolic type have been used in the Palisades containment. Both systems have also been successfully subjected to irradiation tests up to 1 x 1010 rads as reported in ORNL-3589 and ORNL-3916.
Certain small surface area equipment has been coated with systems such as red lead primer on structural steel and various manufacturers standard coatings on equipment. These systems have not been specifically subjected to the tests at post-MHA conditions. Past experience of removing these systems indicates that, if the paint failed, it would become a granular residue and would not fail by large sheets falling from the surface. The granular residue would settle to the floors with minimum possibility of settlement entering the drain piping and recirculation piping. Therefore, failure of these paint systems to a granular residue would not result in plugging of any of the Palisades recirculation or spray equipment.
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120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POT'ENTIA'L FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT The Palisades Plant was one of a number of older plants that were licensed before a standardized set of licensing criteria had been developed. These facilities were later reviewed against a number of generic safety issues that had evolved after the plant operating licenses had been issued. In 1977, to address other issues which had not been imposed generically on all older plants, the Systematic Evaluation Program (SEP) was implemented. The purpose of the SEP was to review the designs of eleven older operating nuclear plants in order to reconfirm and document their safety. The program provided (1) an assessment of the differences between then-current technical positions on safety issues and those that existed when a particular plant was licensed, (2) a basis for deciding on how these differences should be resolved in an integrated plant review, and (3) a documented evaluation of plant safety.
The SEP Topic Vl-1,"0rganic Materials and Post Accident Chemistry" had the stated safety objective to assure that organic paints and coatings used inside of containment do not behave adversely during accidents when they may be exposed to high radiation fields. In particular, the possibility of coatings clogging sump screens was to be minimized. The final evaluation for this topic was contained in an August 3, 1981 letter from the NRC. The evaluation concluded that there is reasonable assurance that the integrity of organic coatings within the containment will be maintained under normal operating conditions and those of a OBA, and that there will be no undue hazard to the health and safety of the public.
No other correspondence was found which contains commitments that address coatings inside the containment.
- Current Controls Applied to Containment Coating Systems Consumers Energy has implemented controls for the procurement, application, and maintenance of Service Level 1 protective coatings used inside of the containment. These controls help assure that the qualifications of the original coating systems are maintained and that any new material introduced into the containment is provided with an acceptable coating system. The requirements of 10 CFR Part 50 Appendix B are implemented through specifications of appropriate technical and quality requirements for the Service Level 1 coatings program. The elements of the coatings program are as follows:
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120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POTtNTIA'L FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT (a)
Procurement of Service Level 1 coatings that would be allowable for new applications or repair/replacement activities are specified in Palisades plant specification A-130, "Technical Specification For Painting". Only qualified coating systems are currently allowed to be used inside containment. These systems are procured from vendors with quality assurance programs meeting the applicable requirements of 1 O CFR Part 50 Appendix B. The applicable technical and quality requirements that the vendor is required to meet are specified by Consumers Energy Company in procurement documents. Receipt inspection activities are conducted in accordance with ANSI N-45.2. This specification of required technical and quality requirements combined with appropriate acceptance activities provide adequate assurance that the coatings received meet the requirements of the procurement documents.
(b)
Only coating systems that have been shown to survive the Palisades post-MHA environment are listed in specification A-130 as acceptable for application inside the containment or on equipment designed* for in-containment use. The qualification testing of Service Level 1 coatings used for new applications or repair/replacement activities inside the containment meets the requirements applicable to Palisades' qualified coating systems.
(c)
The surface preparation and application of Service Level 1 coatings used for new installations or repair/replacement activities inside of containment are governed by plant procedures and specifications. Plant Procedure MSM-M-42, "Application of Service Level 1 Coatings (Paint)" provides the detailed requirements for controlling these aspects of Service Level 1
- coatings.
Containment Inspection and Follow up Activities During the 1998 Refueling Outage, a walkdown of the entire containment building was completed to verify the types and condition of the coating systems inside of the containment. The results of that inspection showed that the original coating systems are generally in place and intact. Only localized minor areas of degradation were noted, and these have since been dispositioned. The walkdown also showed that the original coating system has not been compromised by other coatings since very little coating work has been completed in the containment since original construction.
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120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT Consumers Energy Company is evaluating the guidance provided in EPRI TR-109937 "Guideline on Nuclear Safety-Related Coatings" and, as appropriate, improvements to our existing programs and procedures for Service Level 1 coatings will be implemented upon completion of the evaluation.
Conclusion In summary, the Palisades design basis for in-containment coatings provided that major equipment and structures were to be coated with systems qualified to withstand LOCA environmental conditions. Other small surface area equipment was coated with alkyd systems that were known to fail as a granular residue that would settle to the floors with minimum potential for the settlement to enter the drain and recirculation piping. No subsequent responses to NRG Bulletins or Generic Letters have altered this design basis. Inspection walkdowns have been performed to verify that existing containment coatings are in acceptable condition.
NRC REQUEST (2)
Information demonstrating compliance with item (i) or item (ii):
(i)
For plants with Licensing-basis requirements for tracking the amount of unqualified coatings inside of containment and for assessing the impact of potential coating debris on the operation of the safety related secs during postulated DB LOCA, the following information shall be provided to demonstrate compliance:
(A)
The date and findings of the last assessment of coatings, _and the planned date of the next assessment of coatings.
(B)
The limit for the amount of unqualified protective coatings allowed in the containment and how this limit is determined. Discuss any conservatism in the method used to determine this limit.
(C)
If a commercial-grade dedication program is being used at your facility for dedicating commercial grade coatings for Service Level 1 applications inside of containment, discuss how the program 5
120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POT'ENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT adequately qualifies such a coating for Service Level 1 service.
Identify which standards or other guidance are currently being used
- to dedicate containment coatings at your facility; CONSUMERS ENERGY RESPONSE (2)(i) The Palisades Plant does not have licensing - basis requirements for tracking the amount of unqualified coatings inside of containment and for assessing the impact of potential coating debris on the operation of the safety related secs during postulated DB LOCA.
NRC REQUEST 2(ii)
For plants without the above licensing-basis requirements, information shall.be provided to demonstrate compliance with the requirements of 10 CFR 50.46b(5),
"Long Term Cooling" and the functional capability of the safety-related CSS as set forth in your licensing basis. If a licensee can demonstrate this compliance without quantifying the amount of unqualified coatings, this is acceptable.
CONSUMERS ENERGY RESPONSE 2(ii)
Relevant Historical Licensing Information The following information and referenced materials describe the licensing basis for Palisades as it pertains to conformance with 10 CFR 50.46(b)(5), "Long-term cooling". The specific requirement of interest here is the requirement to provide extended decay heat removal under the accident conditions that are expected to be encountered. This can include appropriate consideration of debris that could block containment emergency sump screens. Our reviews of the SERs issued by the NRC for the Palisades Plant have shown no indication that the NRC formally documented its conclusions about ECCS NPSH in an SER. Reviews performed on the original plant design during licensing, and those system level reviews performed as part of the SEP for the Palisades Plant, have been documented in SERs, but ECCS or CSS pump NPSH are not specifically addressed. From the discussion below, however, it can be seen that explicit NRC 6
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120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT documentation is not necessary to assure that Palisades' coatings are being maintained adequately.
The original design documentation for the ECCS system at Palisades does not specifically itemize assumptions related to debris that could block containment emergency sump screens. The original NRC SER for the Palisades plant concluded that the ECCS system will perform as required, but no specific reference *is provided for related assumptions about debris that could block containment emergency sump screens.
As part of the Systematic Evaluation Program (SEP) reviews of Palisades, SEP Topic Vl-7.E, "Emergency Core Cooling System Sump Design and Test for Recirculation Mode Effectiveness" had the safety objective to confirm the effective operation of ECCS in the recirculation mode. The topic recognized that certain flow conditions could occur in the containment sump which could lead to pump failures. These conditions could include entrainment of air, vortexing and flow losses leading to deficient net positive suction head. This topic was deleted from the SEP scope for Palisades as the issue was being addressed on a generic industry basis by USI A-43, "Containment Emergency Sump Reliability".
The integrated Plant Safety Assessment for the Palisades SEP effort was issued in October of 1982 as NUREG 0820. No new commitments were made concerning containment sump analysis as part of the SEP effort. Separately, USI A-43 has subsequently been closed by NRC.
On June 29, 1982 Consumers Energy responded to an NRC request to provide up-to-date information concerning the unresolved safety issues applicable to
- Palisades. In that letter we described how existing containment and containment sump design attributes and *containment cleanliness controls were adequate to
- address the questions raised by USI A-43. This letter contained no information specific to assumptions related to debris that could block containment sump screens.
Generic Letter 85-22, "Potential for Loss Of Post-LOCA Recirculation Capability Due To Insulation Debris Blockage" was issued on December 3, 1985, and resulted in no actions that led to development of specific assumptions related to debris that could block containment sump screens for the Palisades Plant.
Generic Letter 97-04, "Assurance of Sufficient Net Positive Suction Head For Emergency Core Cooling And Containment Heat Removal Pumps", requested 7
- 120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT information about current NPSH analysis methods, including whether the current design-basis NPSH analysis differs from the most recent analysis reviewed and approved by the NRC for which a safety evaluation was issued. The Palisades response to the generic letter was submitted on January 5, 1998. This letter and response are listed here for completeness only, since relevant portions are restated in this letter.
1996 ECCS NPSH Analysis The current NPSH calculation was completed in November 1996. A 10 CFR 50.59 Safety Evaluation was completed in accordance with plant procedures for this analysis with the determination that an unreviewed safety question does not exist. This latest analysis has not been submitted for review and approval by the NRC.
In a letter dated July 2, 1998, following NRC review of the Palisades reply to Generic Letter 97-04, NRC requested additional information concerning that reply. NRC question (4) and the Palisades response to that question, submitted in a letter dated August 3, 1998, provide additional insight into Palisades' NPSH analyses and associated NRC reviews. NRC question (4) and the Consumers response are restated below:
NRC REQUESTED INFORMATION (4)
In response to question 3, it is stated that the current NPSH analyses were completed in November 1996under10 CFR 50.59.
Discuss the changes made to the analysis between the current NPSH analyses andthe previous NPSH analyses.
CONSUMERS ENERGY RESPONSE
- (4)
The original Safety Evaluation Report dated March 6, 1970, received from the Atomic Energy Commission (AEC), concludes that the ECCS will perform its functions as designed. Palisades has not located any subsequent NRG Safety Evaluation Report that supersedes the original SER in this respect.
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120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT AGCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT Palisades is unable to locate the calculations that may have been reviewed by the AEC or that generated the infonnation in the original FSAR. Because of this status, the current November 1996 NPSH analysis is considered to be a reconstitution of the original calculations. The current analysis was perfonned to generate recirculation flow rates and pressures, verify EOP guidance and decision criteria, and include the effects of pump testing uncertainty and acceptance criteria in the system analysis. The current analysis is considered to have superseded previous NPSH and related system calculations.
This docketed information indicates that, as late as 1997, no specific criteria or requirements existed for assumptions about debris that could block containment emergency sump screens, and none have been generated since that time as a related commitment. The overall acceptability of the ECCS system was based on a general assurance that debris, including coatings debris in particular, would not adversely affect the design basis function of the system. The analysis generated in 1996 is considered to validate the adequacy of the ECCS system to support its design basis function.
The 1996 ECCS system analysis used a factor of 10% containment sump screen surface area blockage to account for debris on the containment sump screens.
During the recent Architectural Engineering (AE) and Engineering and Technical Support (E&TS) inspections, questions were asked about the basis for our use of the 10% factor. In response we have completed an assessment of the sensitivity of the analysis results to the percent of screen surface area assumed to be blocked. The results of that assessment showed that up to 70% of the open flow area of the containment sump screens could be blocked before system flow was degraded to the point of encroaching on required design basis system performance.
Other Activities to Verify ECCS Adeguacy Another effort was completed during the 1998 refueling outage to help validate the Palisades design basis for coatings, and to assess the potential effect that blocking of containment sump screens could have on ECCS system performance. A containment walkdown was completed to verify the type and condition of coatings inside of containment. Analysis was performed to 9
120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04 POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT determine the effect that failed coatings transported to the containment sump screens would have on overall system performance. The quantity of failed coatings that are assumed capable of being transported to the sump are those unqualified or degraded coatings determined to be in the Zone Of Influence (ZOI) for the containment sump. Based on the specific gravity of a material, the time it takes for that material to sink to the floor of the containment can be determined. When this information is coupled with the velocity of flow in the area where the debris is released, equations can be generated to define how far the debris will travel from its release location. From these analyses a ZOI can be determined based on the specific gravity of each kind of debris. A portion of the debris which is present within the ZOI can be expected to be transported to the sump, and debris which is released outside of the ZOI would not be transported to the sump. For the purpose of this analysis effort, conservative assumptions were made. These included assumptions that all unqualified and degraded coatings within the ZOI wouJd transport to the containment sump, and all coatings transported into the sump would collect on the sump screens. In actuality, a significant portion of the coatings within the ZOI has been shown by test to be capable of surviving the LOCA environment. The result of this analysis showed that the increase in system head _losses due to the coating debris on the containment sump screens does not degrade system performance below that previously analyzed.
Conclusion Based on the above discussion, Consumers Energy has concluded that the requirements of 10 CFR 50.46b(5) are met such that it is not necessary to specifically quantify the amount of unqualified coatings inside containment.
NRC REQUEST 2(ii)(a) If commercial-grade coatings are being used at your facility for Service Level 1 applications, such coatings are not dedicated or controlled under your Appendix B Quality Assurance Program, provide the regulatory and safety basis for not controlling the coatings in accordance with such a program. Additionally, explain why the facility's licensing basis does not require such a program.
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120-DA Y RESPONSE TO GENERIC LETTER (GL) 98-04
'\\ POTENTIAL FOR DEGRADATION OF THE EMERGENCY CORE COOLING SYSTEM
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AND THE CONTAINMENT SPRAY SYSTEM, AFTER A LOSS-OF-COOLANT ACCIDENT BECAUSE OF CONSTRUCTION AND PROTECTIVE COATING DEFICIENCIES AND FOREIGN MATERIAL IN CONTAINMENT CONSUMERS ENERGY RESPONSE (a)
Consumers Energy Company does not currently employ commercial grade dedication for Service Level 1 coatings used inside containment at the Palisades Plant.
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