ML18067A779
| ML18067A779 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 11/14/1997 |
| From: | Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML18067A780 | List: |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR GL-87-02, GL-87-2, NUDOCS 9711210062 | |
| Download: ML18067A779 (16) | |
Text
REPORT OF SQUG ASSESSMENT FOR THE RESOLUTION OF (USI) a-46 SUBMITTAL - RESPONSE TO RAI REC'D W1LTR_ DTD 11/14/97 .... 9711210062
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a NOTICE -
ATTACHMENT 1 CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 Response to Request for Additional Information (NRC Letter dated June 19, 1997)
Resolution of Unresolved Safety Issue A-46 13 Pages
ATTACHMENT
- PALISADES NUCLEAR PLANT RESPONSE TO USI A-46 REQUEST FOR ADDITIONAL INFORMATION NRC letter dated June 19, 1997, requested additional information with respect to Consumers Energy's May 23, 1995, response to Generic Letter 87-02. Below is each request for additional information and the Consumers Energy response.
NRG Request:
- 1. Regarding the use of 1.5 times the plant safe-shutdown earthquake (SSE) ground response spectra as a realistic estimate of seismic demand, the staff considers that your September 27, 1996, response did not adequately address the staff's information request. During an August 28, 1996, NRG meeting with the Seismic Qualification Utility Group (SQUG), the staff elaborated on its concern and the primary focus of the request for additional information (RAJ) question. As a result of considerable discussion on the subject, the staff agreed to clarify the question. The following represents the revised question which is being forwarded to affected US/ A-46 licensees for response:
Referring to the in-structure response spectra provided in vour 120-dav-response to the NRG's request in Supplement No. 1 to Generic Letter (GU 87-02 dated Mav 22. 1992. the following information is requested:
(a) Identify structure(s) which have in-structure response spectra (5% critical damping) for elevations within 40 feet above the effective grade, which are higher in amplitude than 1.5 times the SQUG Bounding Spectrum.
(b) With respect to the comparison of equipment seismic capacity and seismic demand, indicate which method in Table 4-1 of GJP-2 was used to evaluate the seismic adequacy for equipment installed on the corresponding floors in the structure(s) identified in Item (a) above. If you have elected to use method A in Table 4-1 of GIP-2, provide a technical justification for not using the in-structure response spectra provided in your 120-day response. It appears that some A-46 licensees are making an incorrect comparison between their plants' SSE ground motion response spectrum and the SQUG Bounding Spectrum. The SSE ground motion response spectrum for most nuclear power plants is defined at the plant foundation level. The SQUG Bounding Spectrum is defined at the free ground surface. For plants founded on deep soil or rock, there may Page 1 of 13
not be a significant difference between the ground motion amplitudes at
- (c) the foundation level and those at the ground surface. However, for sites where a structure is founded on shallow soil, the amplification of the ground motion from the foundation level to the ground surface may be significant.
For the structure(s) identified in item (a) above, provide the in-structure response spectra designated according to the height above the effective grade. If the in-structure response spectra identified in the 120-day response to Supplement No. 1 to Generic Letter 87-02 was not used, provide the response spectra that were actually used to verify the seismic adequacy of equipment within the structures identified in Item (a) above, also, provide a comparison of these spectra to 1.5 times the Bounding Spectrum.
Consumers Energy Response:
(a) At Palisades, both the Reactor Building and the Auxiliary Building have in-structure response spectra at 5% damping which exceed 1.5 times the Bounding Spectrum. However, none of these exceedances occur above the 8 hertz cutoff frequency for the use of Method A. Note that for elevations greater than 16' above effective grade for the Reactor Building internal structure, 5% damped in-structure curves do not exist.
(b) Method A was used for any piece of equipment which met the conditions associated with Method A. Appendix D, the Screening Verification Data Sheets (SVDS), in Section 5 of the Summary Report lists which method was used for determining both capacity and demand for all the equipment on the Safe Shutdown Equipment List (SSEL). In a letter to the NRC dated June 30, 1997, SQUG provided the technical justification for using Method A in lieu of in-structure spectra (Enclosure 1).
With respect to where the Safe Shutdown Earthquake (SSE) is defined, per the Palisades Updated Final Safety Analysis Report (UFSAR), Sections 2.4.3 and 5.7, (Enclosures 2 and 3) the SSE is defined at the ground surface not the foundation level. For the development of the in-structure response spectra, the surface accelerations were applied at the base of the foundation as a simplifying assumption for the analysis. This was how Bechtel typically performed these calculations at the time.
We believe the concern with deconvolution from free field to the foundation level and the potential mis-application of Method A is not applicable at Palisades, Page 2of13
since both the Reactor Building and the Auxiliary Building have their ground
- (c) floors at the plant effective grade and the plant is situated on a deep soil site.
Our in-structure spectra are the Palisades licensing basis spectra and are the spectra referenced in our 120-day response letter to the NRC dated September 21, 1992. The requested plots of the in-structure response spectra compared to the Reference Spectrum (1.5 X Bounding Spectrum) are shown in Enclosure 4. For all elevations for which there are 5% damped curves within 40 feet above effective grade, the Reference Spectrum envelops the in-structure spectra above the 8 Hertz cut-off frequency for equipment evaluations.
NRG Request:
- 2. As noted in the peer review letter provided with your September 27, 1996, submittal, the peer reviewers did not perform walkdowns of inaccessible areas due to radiological concerns, including the containment and a few areas in the auxiliary building which are radiologically controlled. Discuss your walkdown approaches for equipment items listed in the SSEL [safe-shutdown equipment list] that are located in the inaccessible areas, and the basis of concluding that they are adequately installed and hence seismically adequate.
Consumers Energy Response:
The purpose of the peer review, also known as the third party audit, is to assess the effectiveness of the Seismic Review Team's (SRT) walkdowns. This was only intended to be a sampling of the equipment on the SSEL to determine if gross errors had been made by the SRTs. The third party audit was completed in accordance with the Generic Implementation Procedure (GIP) Part 1, Section 2.2.7. The audit team reviewed the same types of equipment that were reviewed by the SRTs and thus, the conclusion is that all the walkdowns are adequate.
The audit team consisted of two of the most highly qualified individuals available to perform this work including a member of the Senior Seismic Review and Advisory Panel (SSRAP).
All equipment on the SSEL was walked down by the SRTs and these walkdowns are documented on the Screening Evaluation Work Sheets (SEWS) in accordance with the GIP.
NRG Request
- 3. As indicated in the peer review letter, a number of observations were made by the peer reviewers for the consideration of the A-46 seismic review team. The
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staff has reviewed the list of observations identified in the letter and found that no documentation regarding resolution of the following items has been provided:
(a) The local shear stress effect (fearing) of the steel skid underneath the steam turbine-driven auxiliary feedwater pump (P-88);
(b) Lack of spacers between fire pump batteries (ED-36 & -37 AIB CID) and lack of restraint for the wooden battery cover; (c) Potential for impact due to proximity of the Instrument AC Bus Transfer Switch Panel (EY-50) to ED-16; (d) Potential interaction hazard for the SIRW [safety injection and refueling water] tank due to collapse of a vent stack adjacent to the containment; and (e) "Seismic housekeeping" items due to lack of restraint of carts, anchorage of tables and similar components, as identified throughout the control room.
You are requested to describe any corrective measures taken to address each of the above peer reviewers' observations and confirm their completion to the NRG.staff.
Consumers Energy Response:
All items identified as observations by the Peer Reviewers were addressed by the Seismic Review Team. Note that for Palisades the peer reviewers completed their review for the SQUG effort and the IPEEE effort at the same time. Therefore, some of their observations were not applicable to the SQUG effort as noted below.
(a) The Steam Driven Auxiliary Feedwater Pump, (P-88) and associated equipment was removed from the SSEL prior to the submittal of the
- Summary Report. Therefore, P-88 is not within the scope of the SQUG program.
(b) The Diesel Fire Pump (P-41) and associated equipment including the batteries (ED-36/37 A/B C/D) are not within the scope of the SQUG SSEL.
The walkdowns for SQUG and IPEEE were completed as one effort, so some of the walkdown information was not applicable to the SQUG project.
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(c) Panel EY-50 is not included on the SQUG SSEL. The potential
- (d) interaction between the two panels EY-50 and ED-16 was evaluated by the SRT and was determined to be acceptable based on the fact that no essential relays are located in cabinet ED-16. Therefore, impact with EY-50 and the affects of relay chatter is not a concern for ED-16.
The vent stack and it's mounting were subsequently evaluated (EA-POC0007899-Stack) and found to maintain structural integrity under the SSE loading.
(e) Palisades Administrative Procedure 1.01, "Material Condition Standards and Housekeeping Responsibilities," provides administrative controls for unanchored equipment in the proximity of safety related equipment.
The Control Room at Palisades was extensively remodeled in 1996 under a modification package which eliminated or anchored the unanchored items of concern noted in the peer review letter. All modification packages are reviewed by GIP qualified Seismic Capability Engineers prior to approval for seismic considerations. The Control Room was again walked down on July 23, 1997 by Seismic Capability Engineers, and was found to be free from interaction concerns from unanchored carts, bookcases, file cabinets and other typical office furniture. Only one printer" stand is still unanchored but is located adjacent to a non-safety related panel and will not impact any safety related panels or equipment.
Other tools and portable maintenance equipment were properly separated from safety related equipment or restrained.
NRG Request: .
- 4. Your September 27, 1996, response to Question 6, regarding outlier resolution, is not acceptable to the staff. You are requested to elaborate on your decision to defer the resolution of identified outliers and your evaluation in support of the conclusion that the licensing basis for the plant will not be affected by your decision. Specifically, you are requested to provide the justification for assuring operability of the affected systems and components while a number of safety-related components in the safe shutdown path have been identified as outliers, thus rendering their seismic adequacy questionable and their conformance to the licensing basis uncertain.
Consumers Energy Response:
The SQUG Program Project Plan provided a methodology for evaluating outliers (Enclosure 5). As delineated in the methodology, all identified outliers were
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initially evaluated against the FSAR requirements. Enclosure 6 discusses the operability status of the outliers. Enclosure 7 provides a general discussion of how outliers and operability were evaluated during the walkdown phase of the project.
In general, for the outliers that were identified as not meeting the screening criteria, it was determined that the FSAR was silent with respect to seismic requirements for this equipment. Therefore, the outliers were determined not to be in violation of the Palisades design basis. The judgement of the SRT was that the equipment was adequate to meet the seismic demand. Thus, no SQUG outliers involved operability or reportability issues. Since none of the outliers represents a deviation from the design basis, resolution of these outliers is not deemed to affect safe operation of the facility. However, resolution of outliers has been ongoing since outliers were first identified.
The majority of the outliers identified were for lack of information with respect to
. the specific type of anchorage. Some of these outliers have been resolved by performing bolt tightness checks as previously noted in the Question 19 response to the previous RAI (Consumers Energy letter dated September 27, 1996). Other outliers are in the process of being resolved either through additional analysis or potential modification.
The NRC, through RAls to various licensees, appears to be questioning the fundamental, programmatic aspects of the resolution of USI A-46 through the use of the GIP-2 methodology. The questioning of this previously accepted methodology was the basis for our earlier response to a schedule for outlier resolution. We have determined that it would not be prudent to undertake designing modifications to the plant until sometime after the NRC has reaffirmed the use of the GIP-2 for the resolution of Generic Letter 87-02 by issuing a site specific SER on the use of the GIP.
In reviewing the Summary Report submitted May 23, 1995, for preparing the response to this RAI, it was discovered that equipment on the SSEL that was classified as "Class O" was not specifically included in the Outlier Section of the Report. However, this equipment is listed as Class 0 on the SSEL and has been reviewed by the SRT commensurate with the other outliers.
As stated in the Consumers Energy letter dated September 27, 1996, Consumers Energy will disposition all USI A-46 outliers at Palisades before the end of the second refueling outage following the receipt of a Palisades specific Safety Evaluation Report (SER) that approves the use of GIP-2 methodology for resolution of USI A-46 at Palisades.
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NRG Request .
- 5. Your September 27, 1996, response to Question 3, regarding the proposed use of the seismic margin methodology in the EPRI [Electric Power Research Institute] NP-6041 procedure, is not acceptable to the staff. The methodology has not been approved by the staff and its conservatism is uncertain at this point.
It is, therefore, not endorsed by the staff for the analysis of safety-related systems and components, including the resolution of mechanical, electrical, and structural component outliers in the A-46 program. You are requested to reevaluate your program and ensure that all the identified outliers will be resolved using the plant licensing basis methodologies or other approaches acceptable to the staff.
Consumers Energy Response:
As requested, methods for resolving outliers are being reevaluated. However, outlier resolution is not an item that is covered by the SQUG-GIP and, therefore, is not addressed in our Summary Report.
Only two tanks, the Condensate Storage Tank (T-2) and the Safety Injection and Refueling Water Storage Tank (SIRW Tank, T-58), were evaluated using the NP-6041 methodology. T-2 has subsequently been re-assessed using the GIP
- Section 7, and was determined to satisfy the GIP criteria.
The SIRW Tank, T-58, remains as an outlier and, as such, is being resolved the same as other outliers. As stated in the Consumers Energy letter dated September 27, 1996, Consumers Energy will disposition all USI A-46 outliers at Palisades before the end of the second refueling outage following the receipt of a Palisades specific Safety Evaluation Report (SER) that approves the use of GIP-2 methodology for resolution of USI A-46 at Palisades.
NRG Request:
- 6. Your September 27, 1996, response to Question 8, as to why the maximum acceleration represented by the floor response spectra (FRS) at higher elevations is less than that at lower elevations, is that the FRS at higher elevations peak in the first mode (1.94 Hz) and that at lower elevations they peak in the second mode (5.52 Hz). We find this explanation unacceptable. In the modal analysis as performed, the response of the structure at a point is a combination of different modes of vibration through the use of participation factors. It appears that there is a need for further clarification on how FRS were generated. Provide a detailed description of how the FRS as shown in Appendix B of the Palisades A-46 summary report were generated. The information Page 7 of 13
provided should include the actual response spectra generated in addition to the smoothed spectra.
Consumers Energy Response:
The floor spectra were generated by the Bechtel Corporation using typical evaluation techniques at the time. This process is described in Enclosure 8 for the Auxiliary Building and Enclosure 9 for the Reactor Building. Also provided are the unsmoothed and unbroadened computer generated spectra as requested.
These spectra generated by Bechtel are the Palisades original licensing basis spectra and have been reviewed and approved by the NRC, [reference NRC letter, "Safety Evaluation of the Palisades Plant 120-Day Response to Generic Letter 87-02, Supplement 1 (TAC NO. M69468)," dated November 23, 1992].
With respect to the previous explanation regarding the possibility of floor spectral accelerations being higher for a lower floor than the floor above, the following is provided:
We have confirmed the possibility of this occurrence through further review of the building models and by discussion with a noted academic expert. In reviewing the Reactor Building modes, the first mode is predominantly a soil mode with the Reactor Building translating and rotating (rigid body modes) atop a soil spring. The second mode at 5.52 Hz is the most significant mode and responds at the peak of the Housner ground spectrum. This mode's peak response is at ground level Uunction of the soil spring and building mass model) and each elevation above ground level has a smaller modal amplitude than the node (floor) below it. In other words, the mode shape amplitude at 608' is larger than that for 646' or 684'. Given the significance of the second mode and its alignment with the peak of the ground spectrum, the resulting spectra is reasonable.
In reviewing the Auxiliary Building spectra, the numerical differences in the peak values are not significant (e.g. peak at 0. 76g at 601' verses 0.80g at 589'). As with the Reactor Building, the second mode in the East-West direction has a higher modal amplitude for the 601' node than for the 589' node. This mode is significant because it also responds at the peak of the Housner spectrum.
Therefore, our conclusion does not change from that stated in previous submittals, in that the resulting spectra is reasonable .
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NRG Request:
- 7. In your September 27, 1996, response to Question 9, you provided evaluations of the adequacy of the anchors for two 480-volt motor control centers (EB-01 and EB-26) and one charging pump (P-55C). For EB-01, there are three anchors with two different anchor types and for EB-26 there are ten anchors of the same anchor type. Both EB-01 and EB-26 are located in the auxiliary building at floor elevation 607. Even though there is no response spectrum established for this elevation, it can be interpolated from the response spectra at floor elevations 601 and 610 as provided in Appendix B. An explanation should be provided for the following:
(a) For the screening evaluation of EB-01 both the capacity based on 1.5 times the Bounding Spectrum and the demand based on Design Floor Response Spectrum are shown. For the screening evaluation of EB-26 the capacity based on 1.0 times the Test Response Spectrum and the spectra on which the demand is based are not provided. Provide the missing information. Also indicate how the capacity based on spectra is used in establishing the safety factors as shown in the table on sheet 1O of 13 for EB-01 and on sheet 11 of 11 for EB-26 of Enclosure 3.
(b) The spectral values for both EB-01 and EB-26 are 1.64g for east-west (E-W) and north-south (N-S) and 0.20g for vertical. However, in calculating the safety factors as shown on sheet 1O of 13 for EB-01 and sheet 11 of 11 for EB-26, different values, 0. 656g in the horizontal direction and
- 0. 080g in the vertical direction are used. Provide on explanation for these differences.
(c) In combinations of spectral accelerations, why are there no combinations involving 1. 64g in both N-S and E-W?
(d) For P-55C, which is located in the auxiliary building at elevation 590, the spectral values shown on sheet 3 of 13 are different from those shown on sheet 13 of 13. Explain the apparent discrepancies. Are the procedures similar to those used for EB-01 and EB-26 in calculating the factor of safety?
Consumers Energy Response:
(a-d) For all three calculations, the process of calculating the anchor loads and factors of safety are the same. For anchorage calculations for equipment at elevation 607' in the Auxiliary Building, the in-structure spectra for elevation 61 O' at 5%
damping are used (Summary Report, Section 5, Appendix B, Figure B-12). For
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pump P-55C, the ANCHOR program initially uses a conservative program
- default acceleration of 1.875 X Ground Response Spectra (GRS) at 20 hertz for evaluating the anchorage instead of the in-structure spectra, unless this is overridden. For the P-55C evaluation, the default value is used.
Typical for these anchorage analyses, the ANCHOR program approximates a SRSS of the anchor loads for computing interactions using the 100-40-40 rule.
The maximum accelerations are not required to be applied in all three orthogonal directions simultaneously in order to determine an anchorage interaction. Since the ANCHOR program (or any other program) cannot solve the interaction equations by using SRSS methods, the SRSS is approximated by applying the maximum acceleration in one orthogonal direction (100%)
combined with 40% of the maximum acceleration in the other two directions for each orthogonal direction (the 100-40-40 rule); thus three sets of interactions for each anchorage. Using this approximation an interaction for each bolt is calculated for each loading condition and compared to an allowable to determine the factor of safety.
(a) The "missing" information requested, relative to the test response spectra and the 2% damped in-structure curve has no bearing on the anchorage evaluation.
This information is only used for a comparison of capacity versus demand for the equipment itself as delineated on the Screening Evaluation Work Sheets
- (SEWS). For the anchorage evaluation, the same in-structure spectra as noted above (elevation 610', 5% damped) are used for calculating the demand in accordance with the GIP.
NRG Request:
- 8. From your limited analytical review (LAR) data sheet No. LAR 005 for a cable tray computation it appears that you analyzed a highly indeterminate structure as a determinate structure. The results of your analysis may not represent the actual behavior of the structure unless the joints of the members and the supports are free to rotate. Provide the details about the joints and supports to justify such an assumption; otherwise the subject raceway should be analyzed as an indeterminate structure.
Consumers Energy Response:
The parts that connect the horizontal to vertical members and to the structure for this support (and all cable tray supports) are the typical Unistrut 90° fitting (part numbers - P1346, P1026) or equivalent. The connection details were reconfirmed by walkdown to meet the requirements of GIP Figure 8-7. These types of fittings have been determined to provide little restraint from rotation Page 10of13
during real earthquakes. This point has also been confirmed by shake table
- testing of actual cable tray systems, by URS/Blume in the early 1980's for the Systematic Evaluation Program (SEP) effort completed for Palisades. The assumption that these joints are free to rotate is consistent with the methodology presented in the GIP, Chapter 8. SQUG has addressed the cable tray ductility issue in a letter to the NRC dated June 11, 1997 (Enclosure 10).
NRG Request:
- 9. On sheet 1 of 6 of the screening evaluation work sheet for tank T-73, in the computation of estimated weight, the weight of water is calculated on the basis of a tank radius of 4.0625 feet instead of (4. 75 - .6875112 =4.692). Provide an explanation for this discrepancy.
Consumers Energy Response:
This is an error made in the conversion of terms from inches to feet which incorrectly calculated the weight of water in the tank. The analysis has been revised correcting this error without affecting the conclusion that the tank is still adequate.
NRG Request:
- 10. In section 5.0, "Conclusion" of "Seismic Analysis of SIRW T-58 Tank, Calculation No. C-019," you stated that the outlier will be resolved if the concrete pad reinforcement is verified. Confirm if this has been done. If not, what is your plan for resolution of this open item?
Consumers Energy Response:
The Safety Injection and Refueling Water Storage Tank (T-58) remains an outlier. The tank and its anchorage are judged to meet the original design requirements for seismic restraint. Additional document searches will be conducted to try to confirm the required reinforcing. To the extent practicable, trying to physically locate reinforcing steel using a rebar detector or other means is an option also under consideration. This outlier is being dispositioned the same as other outliers. As stated in the Consumers Energy letter dated September 27, 1996, Consumers Energy will disposition all USI A-46 outliers at Palisades before the end of the second refueling outage following the receipt of a Palisades specific Safety Evaluation Report (SER) that approves the use of GIP-2 methodology for resolution of USI A-46 at Palisades.
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NRG Request:
- 11. On sheet 2 of 3 for analysis of tanks T-53A and T-538, it appears that the frame which supports the tanks is statically unstable for the horizontal seismic force unless horizontal members are added at the top and bottom. Confirm that these members actually exist and are simply not shown in the figure; otherl/vise a modification of the frame should be considered or additionaljustification regarding the seismic stability of these tanks should be provided. -
Consumers Energy Response:
There are no "horizontal" members other than the diagonal bracing. The tank shell itself provides for the load transfer at the top of the braced frame.
Regardless, the tank frame is statically stable considering only the tension bracing with the vertical legs and the tank shell transferring the load to the legs.
The concrete floor and anchorage acts as the load resistance at the base of the legs.
As identified in the calculation previously provided, (Consumers Energy letter dated September 27, 1996), the diagonal bracing is inadequate as well as the anchorage for the baseplates. This outlier is being dispositioned the same as other outliers. As stated in the Consumers Energy letter dated September 27, 1996, Consumers Energy will disposition all USI A-46 outliers at Palisades before the end of the second refueling outage following the receipt of a Palisades specific Safety Evaluation Report (SER) that approves the use of GIP-2 methodology for resolution of USI A-46 at Palisades.
NRG Request:
- 12. In the evaluation of anchorages for tanks T-53A and T-538, and heat exchangers E-60A&8, the results show the anchorages are not adequate and remain as outliers. However, the outliers were disposed of without further detailed analysis. Such a procedure of outlier resolution is unacceptable. A detailed analysis to resolve each outlier is requested.
Consumers Energy Response:
These outliers have not been dispositioned or resolved, only the tanks and support structure were evaluated for adequacy. The wording in the two evaluations previously provided suggests that these outliers 'might' be resolved by using the new Reg Guide 1.60 spectra in conjunction with other analytical tools. These outliers will be dispositioned the same as other outliers. As stated in the Consumers Energy letter dated September 27, 1996, Consumers Energy Page 12of13
will disposition all USI A-46 outliers at Palisades before the end of the second refueling outage following the receipt of a Palisades specific Safety Evaluation Report (SER) that approves the use of GIP-2 methodology for resolution of USI A-46 at Palisades.
NRG Request:
- 13. You claimed that the joint details as shown on sheet 1 of 4 of LAR data sheet No. LAR 012 for a cable tray are such that the joints are free to rotate. With the angles forming the joints, the staff has reservations with this claim. Please provide a justification for this claim.
Consumers Energy Response:
The details of this joint are consistent with the GIP, Section 8 evaluation techniques for evaluating cable tray supports. The configuration of the joint meets the requirements of the GIP, Figure 8-7 for ductile connections. As stated above in the response to Question 8, the ductility of this joint is based on seismic experience and testing instead of standard empirical calculations or evaluation techniques.
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ENCLOSURE 1 CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 SQUG LETTER TO THE NRC DATED JUNE 30, 1997 Entitled GENERIC ISSUE INCLUDED IN NRC'S REQUESTS FOR ADDITIONAL INFORMATION ON USE OF GIP METHOD A