ML20138E089
Text
-
r Jj
']
- par UNITED STATES y"
NUCLEAR REGULATORY COMMISSION o
g g
WASHINGTON, D. C. 20555
\\...../
APR 2 6 GM j
Docket Nos.:
50-335 and 50-250 50-251 MEMORANDUM FOR:
Herbert N. Berkow, Director Project Directorate II-2
)
Division of Reactor Projects I/II FROM:
James A. Norberg, Chief Mechanical Engineering Branch Division of Engineering
SUBJECT:
FLORIDA POWER AND LIGHT COMPANY'S RESOLUTION OF USI A-46 FOR ST. LUCIE UNIT 1 AND TURKEY POINT UNITS 3 AND 4 1
The staff is currently performing an evaluation of the Florida Power and Light Company's, the licensee, implementation program for resolving Unresolved Safety Issue (USI) A-46 as delineated in Generic Letter (GL) 87-02. Attach-
! i ment 1 provides important background information on this issue. The staff's i
effort consists of the review of the licensee's submittal dated September 8,
!{
1992, which included, as enclosures and attachments:
(1) the licensee's l
response to the staff's Request for Additional Information (RAI) of March 18, 1992, (2) the licensee's final report of its implementation program for J
resolving USI A-46 at St. Lucie Unit 1, and (3) Piping and Instrument Diagrams (PIDs) showing the USI A-46 safe shutdown path and corresponding equipment.
t 4 j
The staff has identified several areas of the licensee's September 8,1992, submittal, for which additional and/or clarifying information is needed.
In 1
l some cases, the staff has identified areas where the licensee has not provided
{
adequate and/or acceptable responses to the staff's RAI of March 18, 1992.
t provides a discussion and evaluation of selected items from the i
l licensee's response.
In other cases, new comments and questions were developed based on informs' ion in the supporting documents which accompanied the licensee's response. Accordingly, the licensee is requested to provide responses to the questions and comments in the enclosure.
It is noted that the staff held a meeting with the licensee on April 6, 1993, to discuss the major unresolved programmatic issues (these issues were addressed in Items 1 through 4 and Item 7 of the staff's RAI dated March 18, 1992). These issues, which are not discussed in the enclosed RAI, date back to the staff's letter dated August 4, 1989, and involve the licensee's definition of its safe-shutdown path, and the licensee's request for an exemption from peforming a relay evaluation as part of its USI A-46 program.
At the end of the meeting, the licensee indicated that it would reevaluate its 4i i
positions on these issues, and would contact the staff when it is prepared to V
l discuss any changes to its postions. The staff realizes that the resolution of many issues discussed in the enclosed RAI will likely be affected by the
[
final resolution of the major programmatic issues.
Thus, in order for the f
staff to continue with a meaningful detailed review of the licensee's program, it is important to resolve the programmatic issues as soon as possible.
,$$L280non x
\\
ho42 90 D l} O E
C
l i
l
~
H. N. Berkow 2
t If you have any questions, please contact M. McBrearty at 504-2725.
ORIGINAL SIGNED L
U/:
James A. Norberg, Chief
,1 Mechanical Engineering Branch Division of Engineering 1
l l
Enclosure:
Request for Additional Information Attachments:
(1)
Background Information (2)
Discussion of Licensee's l
Response lo March 18, 1992, RAI i
l DISTRIBUTION:
Gent,tal File B PF/RP l
SVarga l
BDLiaw l
Glainas i;
GBagchi i
JWermiel RJones KManoly HMcBrearty(CHRON)
PYChen HAshar KDesai JStewart LRaghavan l
JNorris AA 0FFICE EMEB:DE:eh EMEB:DE EGdikpI SRX, DST EME1f]DE///
MMCBrkrh KMabh IBagcht kes JNNkr'g uw 9 //f'/93 t//11/93 k/)d/93 Y/ /93 Y/S/93 DATE I
0FFICIAL RECORD COPY FILENAME: G:\\McBrearty\\fPL2cov l
)
ENCLOSURE I RE0 VEST FOR ADDITIONAL INFORMATION REGARDING FLORIDA POWER AND LIGHT COMPANY'S RESOLUTION OF USI A-46 FOR ST. LUCIE UNIT 1 AND TURKEY POINT UNITS 3 AND 4 1.
Item No. 5 of the staff's March 18, 1992, RAI, requested that the licensee list the equipment and equipment categories, including those inside containment, which are part of the safe-shutdown path, but which have been excluded from the sei:mic adequacy verification program. The licensee was also requested to provide a detailed technical justification for the exclusions, unless the equipment was excluded in accordance with Generic Letter (GL) 87-02.
In its response, the licensee provided Piping and Instrument Diagrams, along with associated equipment lists, which identify both the items included in the USI A-46 walkdowns and all items which were excluded (Enclosure A to the licensee's September 8, 1992, letter). The licensee stated that the exclusions consist of equipment which are either not within the lesser i
scope of FPL's program, passive items, or items excluded by the conditions set by GL 87-02.
Aithoughthelicenseehasidentifiedpassiveequipmentitems,the licensee did not clearly justify why the remaining equipment items were excluded (e.g., there were no valves included in the walkdowns).
Therefore, as requested in the RAI, the licensee should state the specific technical justification for excluding individual pieces of equipment. The staff cautions that it is not adequate to justify excluding an equipment item by simply stating that the item is not within the lesser scope of FPL's program, since, as discussed in the Background Information, the licensee's scaled-back program has never been fully defined, reviewed and approved.
(note: The staff recognizes that the Auxiliary Feedwater System was previously inspected as part of GL 81-14, and was therefore exempt from further review.)
2.
As discussed in Item 1 of Attachment 2, the staff finds the licensee's response to Item 6 (use of SSRAP bounding spectra) of the staff's RAI unacceptable. Accordingly, the licensee is again requested to provide criteria and procedures, or references, to show that the equipment items at St. Lucie Unit I and Turkey Point Units 3 and 4, within the scope of USI A-46, are within the experience data base.
3.
In response to Item 9 of the staff's RAI related to seismic adequacy of the above ground vertical tanks, the licensee stated that its program to resolve USI A-46 included the evaluation of tanks in order to resolve USI A-40.
The licensee stated that information on the seismic adequacy of above ground steel tanks is provided in the Final Report for St. Lucie. However, the licensee also states that the adequacy of ring foundations for the steel tanks was not identified as a concern in either the original GL 87-02 or USI A-40, and that it was not addressed in its Seismic Program. The provision for checking the adequacy of tank-foundations is a part of the resolution of USI A-40 as reflected in
t I
2 Section 11.14.1 of SRP 3.7.3 dated August 1989. Therefore, the licensee
?
is requested to provide information on the adequacy of all of the applicable tank-foundations.
4 4.
As discussed in Item 3 of Attachment 2, the staff accepts EPRI NP-5228, Revision 1 for anchorage criteria, but does not accept the licensee's exclusion of torque tightness test %g. Therefore, the licensee is 4
i requested to provide information on the method of ensuring the tightness checking of equipront anchorages. Additionally, as discussed in Item 3 of Attachment 2, ine licensee needs to revise the St. Lucie Final Report to reflect a commitment to the final version of EPRI NP-5228, Revision 1.
5.
In Section 4.2.3, the licensee stated that it used a factor of safety (FS) of 3.0 for all expansion anchors. This position is inconsistent with EPRI NP-5228, Revision 1, which, in some cases, specifies a FS greater than 3.0 for expansion anchors, such as in cracked concrete.
The licensee needs to justify the use of a single FS of 3.0 for all expansion anchors considering the criteria in the EPRI Report.
6.
The last paragraph of Section 4.2.3 on page 19 of the St. Lucie final report describes how SRT judgement was used to evaluate equipment anchorages during the walkdowns. According to the report, "When the anchorage was obviously rugged, SRT judgement was used to assess anchorage adequacy. This judgement was performed in the context of the above criteria."
It is not clear as to what criteria the licensee is referring. Therefore, the licensee needs to identify the specific criteria used to make such judgements (e.g., does the anchorage satisfy the criteria of EPRI NP-5228, Revision 17).
7.
On page 6 of the Appendix A Walkdown Procedure, the licensee discussed two levels of " screening-out" equipment anchorages during the walkdowns.
For the first screening, the licensee stated that the anchorage was evaluated to determine if it is in conformance with the design basis for the plant. However, in its discussion of the seismic design basis for St. Lucie Unit 1 (Section 3.4 on page 9 of the final report), the licensee indicated that there were no specific commitments with regards to the seismic design of anchorage for mechanical and electrical equipment. The licensee should explain in detail how the first i
" screening-out" of equipment anchorage was performed (e.g., was the anchorage screening-out based on the criteria in NP-5228, Revision 17).
In addition, the licensee discussed the SRT's use of judgement for the second level " screening-out" of equipment. The licensee needs to identify and describe in detail the specific criteria used by the SRT to make these judgements.
8.
Justify the assumption used in many of the anchorage calculations that the minimum concrete compressive strength was greater than or equal to 3500 psi.
It is noted that EPRI NP-5228, Revision 1 requires the use of a capacity reduction factor for concrete strengths below 3500 psi.
?,
I 3
i 9.
The equipment data sheets (EDS) completed by the SRT do not specifically address many of the anchorage concerns discussed in EPRI NP-5228, Revision 1.
The EDS do not specify checks for such items as anchor i
spacing, free-edge distance, gaps under bolted anchorage, effects of prying action, etc. The licensee needs to explain how these types of concerns were considered during the walkdowns and evall ations.
For example, how were the capacity reduction factors for closely-spaced anchors, near-edge anchors, cracked concrete, etc., which are described in EPRI NP-5228, Revision 1, considered in the anchorage evaluations?
10.
Reference 13 cited in the final report (Section 4.2.1) requires the comparison of applicable IRS with 1.5 times the bounding spectrum. No such comparison for critical equipment is provided.
Provide documentation of these comparisons for the critical equipment.
- (
11.
Based on the review of the IRS, the licensee determined that if the equipment natural frequency was above 4.5 Hz, a 0.59 demand would be used to assess the anchorage.
if the equipment natural frequency was below 4.5-Hz, a 1.29 demand would be used to assess the anchorage (Section 4.2.3 of final report). However, for equipment where IRS are not available, the anchorage demand is assessed using a horizontal acceleration of 0.39 as per Reference 13 cited in the final report.
Provide justification for such discrepancy in assessing the anchorage capacity.
12.
The adequacy of the above ground vertical tanks has been assessed by considering all anchor bolts to be subjected to varying amounts of tension loads and the small area of the tank shell resisting the compression load.
Provide an assessment of the buckling mode of failure of the tank shell.
13.
For above ground tanks, provide an assessment of shear stresses on anchor bolts and tank shell considering the vertical component of the postulated earthquake.
14.
The staff's review indicates that the licensee has not confirmed the adequacy of the safety related electrical raceways (cable trays and 4
conduits) and their supports, which is within the scope of the original GL 87-02.
Provide information on the plans for resolving this item of the Generic letter.
I i
O ATTACHMENT 1 BACKGROUND INFORMATION On June 2,1988, the staff met with members of the Florida Power and Light Company, the licensee, to discuss the licensee's response to Generic Letter (GL) 87-02, " Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating Reactors, Unresolved Safety Issue (USI) A-46," dated i
february 19, 1987, for St. Lucie Unit 1 and Turkey Point Units 3 and 4.
The licensee made a presentation to support its position that GL 87-02 should not apply to their plants because of the low seismicity in Southern Florida.
Although the staff did not accept the licensee's request to be exempt from responding to GL 87-02, the staff suggested that it would be appropriate for i
the licensee to propose a scaled-back program to address USI A-46 (see June 16, 1988, meeting summary).
By letter dated August 4,1988, the licensee submitted its implementation program.
In a letter dated August 4, 1989, the staff provided its evaluation of the licensee's program, and concluded that the proposed program only addressed part 6f the basic USI A-46 concern. The staff requested that the licensee augment its program, and identified specific pre-walkdown items and post-walkdown items which the licensee should add to its program..
Additionally, the staff stated that the pre-walkdown items should be submitted to the staff and approved before the actual walkdowns take place. The licensee submitted a revised program on December 13, 1989, and indicated that it planned to begin implementation during outages in the Spring of 1990, provided that the staff issued a Safety Evaluation accepting the revised program by January 30, 1990. Otherwise, the licensee stated that it would implement the program during 1991 outages. Although the staff was not able to evaluate the program by January 30, 1990, the licensee performed its plant walkdowns in the Spring of 1990, and has since fully implemented its program.
In subsequent written correspondences, and in a conference call and a meeting with the licensee, the staff has maintained that the licensee has not provided adequate responses to its August 4, 1989 letter, and therefore, the staff has been unable to evaluate the adequacy of the licensee's implementation program.
It is important to note that, although the staff had agreed that it was appropriate for the licensee to implement a scaled-back USI A-46 program, the licensee has never fully defined the scope of its program, nor has the licensee provided the basic programmatic information necessary for the staff to determine the acceptability of the licensee's overall approach for resolving USI A-46.
The essential information was previously requested in staff letters dated August 4,1989, and January 23, 1991.
In its responses to those letters, the licensee provided some, but not all, of the requested information. On February 27, 1992, the staff held a meeting with the licensee to discuss what information was still needed. As a result of the meeting, the staff issued an RAI dated March 18, 1992. The staff has reviewed the licensee's September 8, 1992, response, and has identified several areas of the licensee's submittal for which additional and/or clarifying information is still needed.
a ATTACHMENT 2 DISCUSSION OF SEPTEMBER 8. 1992. RESPONSE TO RAI This discussion provides evaluations of the licensee's response to selected items in the staff's March 18, 1992, RAI, and provides information to clarify and support the staff's RAI provided in Enclosure 1.
1.
Use of SSRAP Boundino Soectra Item No. 6 of the staff's RAI requested that the licensee provide the criteria and procedures, or references, to show that the equipment items at St. Lucie Unit I and Turkey Point Units 3 and 4, within the scope of USI A-46,'are within the experience database. The licensee's response indicated that Section 4.2.1 of the licensee's final report for St. Lucie Unit I describes the use of the SSRAP Bounding Spectrum.
In Section 4.2.1, the licensee ~ stated that, in making equipment capacity vs. demand evaluations, it performed the evaluations on a plant-specific basis rather than on an equipment-specific basis. Specifically, on page 16 of the St. Lucie Unit I final report, the licensee stated, "The question of seismic capacity vs. demand for equipment was judged to be acceptable on a generic basis since 1.5 x Bounding Spectrum enveloped the floor response spectra." As such, the licensee concluded that all of the equipment at St. Lucie Unit I satisfied the seismic capacity vs.
demand evaluation. The licensee indicated that the same methodology was used for the capacity vs. demand evaluations performed for Turkey Point Units 3 and 4.
The licensee's response to the RAI (i.e., Section 4.2.1 of the final report for St. Lucie Unit 1) did not answer the staff's question, in that it did not identify the criteria used to demonstrate that the i
equipment items at St. Lucie Unit I and Turkey Point Units 3 and 4 are j
within the scope of the experience database.
In order to use the SSRAP i
Bounding Spectrum for representing an equipment item's seismic capacity, l
the licensee pylt demonstrate, on an equipment-specific basis, that each i
of the equipment items, for which a seismic capacity vs. demand i
evaluation is required, is similar to an equipment category within the i
scope of the experience database. Thus, the licensee's t?thod of performing the capacity vs. demand evaluations on a plant-specific basis is not acceptable. Accordingly, the licensee is again requested to provide criteria and procedures, or references, to show that the equipment items at St. Lucie Unit I and Turkey Point Units 3 and 4, within the scope of USI A-46, are within the experience database.
It is noted that Sections 10 through 22 of the SSRAP Report, Revision 4, dated February 28, 1991, provide partial descriptions of the experience data base equipment categories, along with several caveats and exclusions for each equipment category. However, during the staff's review of the Seismic Qualification Utility Group's Generic l
Implementation Procedure (GIP-2) for resolving USI A-46, the staff determined that the equipment descriptions (and the caveats and l
exclusions) provided in the SSRAP Report were not complete.
)
,)
l l
j 2
Descriptions of the equipment categories, and specific caveats pertaining to each equipment category, which the staff has fand acceptable for demonstrating the applicability of the experience data base, are included in Appendix B of GIP-2 as corrected on February la, 1992, and as supplemented by the staff's Supplementary Safety Evaluatica Report No. 2 dated May 22, 1992. The descriptions and caveats included i
in GIP-2 were developed from information contained in (1) the SSRAP Report, Revision 4, dated February 28, 1991, (2) EPRI Report NP-7149, dated March 1991, and (3) EPRI Report NP-5223, Revision 1, dated February 1991.
2.
In-structure Response Spectra In response to Item 8 of the staff's RAI related to the development of in-structure response spectra (IRS), the licensee states that providing this information is not within the scope of work which it committed to for resolving USI A-46.
However, the licensee i. willing to discuss this information as divorced from the resolution of USI A-46.
As the staff's objective is to assure that proper procedures are used in verifying the adequacy of the equipment, the staff is ready to discuss this issue during future audits of the St. Lucie Unit I and Turkey Point Units 3 and 4 USl A-46 programs.
3.
Anchoraae C.'iteria Item No. 11 of the staff's RAI requested that, for equipment anchorage criteria, if the licensee intends to commit to Volume 1 of EPRI NP-5228, Revision 1, dated June 1991, then the licensee should submit for staff review any exceptions or deviations from that report. The licensee responded that the only exception taken was for torque tightness testing. The licensee did not provide any justification for excluding torque tightness testing from its program. The staff has previously concluded that the criteria contained in EPRI NP-5228, Revision 1, dated i
June 1991, is acceptable for performing equipment anchorage evaluations for USI A-46.
However, the staff believes that tightness checking is one of the most important attributes in ensuring the integrity of the bolted expansion anchorages, and, therefore, the licensee's proposed exception is not acceptable. The staff has accepted the concept of random sample testing of the affected anchorages. The licensee is requested to provide information on the method of ensuring the tightness checking of equipment anchorages.
Additionally, although the licensee, in its response to the staff's RAI, committed to EPRI NP-5228, Revision 1 for the detailed anchorage evaluation criteria and procedures for its USI A-46 program, the licensee's final report for St. Lucie Unit I references a preliminary version of EPRI NP-5228 dated May 1987 which the staff has not endorsed.
The preliminary version of the EPRI report is included in the reference section of the St. Lucie Unit I final report, and it is also cited as a reference in many of the Appendix C supportina calculations. The staff
1 i
4"**
3 is continuing to review the anchorage criteria and their implementation l
by the licensee. The licensee should revise the St. Lucie Final Report to meet the commitments made in the September 8, 1992, response to the i
RAI.-
i i
4.
Use of ACI 349. Aooendix B 1
Item No.12 of the staff's RAI stated that, since ACI 349, Appendix B I
has not been approved by the staff, FPL should delete any reference to that report in its submittal on anchorage criteria. The licensee i
responded that it will delete any reference to ACI 349 Appendix B in any i
future revisions to the St. Lucie Unit I and Turkey Point Units 3 and 4 i
reports. A review of the final report indicates that in the anchorage calculations, the criteria of ACI 349, Appendix B have been used.
The y
staff is continuing to review the anchorage criteria and their implementation by the licensee.
In the mean time, the St. Lucie Final Report should be revised to meet the commitments made in the September 8,1992, letter.
J i
I q
i I
I t
i e