ML20056A751
| ML20056A751 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 08/07/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20056A750 | List: |
| References | |
| IEIN-88-004, IEIN-88-4, NUDOCS 9008090147 | |
| Download: ML20056A751 (4) | |
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E SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULA110N i
FACILITY OPERATING LICENSE NOS. DPR-51 AND NPF-6 ENTERGY OPERATIONS. INC.
ARKANSAS NUCl. EAR ONE. UNIT NOS. 1 AND 2 DOCKET NOS. 50 313 AND 50-368 FIRE BARRIER SEAL PROGRAM i
1.0 INTRODUCTION
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'During the Appendix R inspection of Arkansas Nuclear One, Units 1 and 2 (ANO j
1&2) on May 4-8, and June 8-12, 1987 (Inspection Report 87-14), the NRC raised
' concerns regarding the qualification of penetration seals installed in the
' plants. _The. licensee was requested to submit design details and fire test data j
to substantiate the qualification of-installed penetration seals in each unit.
By letter dated September-17, 1987, the licensee provided their initial 4
submittal regarding the NRC's concern.- As part of the resolution of this issue,theNRC'issuedseveralRequestsforAdditionalInformation(RAls),which the licensee 4 responded to.
In addition, a site visit was made. This Safety Evaluation (SE) provides a discussion and evaluation of information provided by the licensee, and information obtained during the site visit.
Input to this SE was provided by Science Applications International Corporation, an NRC
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contractor.
2.0 DISCUSMCN Section0.1.(j)ofAppendixAtoBranchTechnicalPosition(BTP)APCSB 9.5-1 states, " Floors, walls and ceilings enclosing separate fire areas should have-a minimum fire rating of three hours. Penetrations in these fire barriers, including conduits.and piping,.should be sealed or closed to provide a fire resistance rating at least equal to that of the fire barrier itself...".
In
. addition, because of concerns relating to penetration seal installations at a number of plants, the NRC issued Information Notice 88-04, " Inadequate Qualification and Documentation of Fire Barrier Penetration Seals," on y
February 5,1988.
308090147 900807
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Durino the Appendix R inspection of ANO 1&2, the NRC expressed concern that some of the penetration seals installed in the plants might not have been rated equivalent to the barriers themselves, as specified in NRC guidance. At the time of the inspection, the licensee was not able to justify the adequacy of their fire barrier penetration seals. The NRC reouested that the licensee provide a su' <ttal which would include documentation on the rating of the installed fire barrier penetration seals.
The licensee provided a submittal to the NRC on September 17, led in the plants.1987, which included design detail drawings for penetration seals instal The submittal also contained fire test reports intended to support the rating of the design details. The submittal identified that fire test reports to support several of the details were not complete and that they would be provided to the NRC when available.
On December 21, 1968, the NRC received a submittal from the licensee containing fire test data to support the rating of the remaining seals from the September 17, 1987 submittal.
An evaluation of the licensee's submittals was begun by the NRC using criteria from BTP APCSB 9.5-1 and it was determined that several concerns needed to be addressed by the licensee. The NRC transmitted an RAI to the licensee's original submittal on January 9,1989. Additional concerns regarding the d
December 21, 1988 submittal were transmitted to the licensee by RAI dated February 23, 1989. By letter dated March 31, 1989, the licensee responded to the January 9,1989 RAl. The NPC received a response to the February 23, 1989 RAI by submittal dateo May 11, 1989.
After review of the licensee's responses to the areas of concern, the NRC was still not satisfied that the penetration seal program was adequate.
Because of additional concerns, the NRC made a site visit in October of 1989 to verify the adequacy of installed penetration seals. As a result of discussions with the licensee during this visit, the licensee agreed to provide a description of their fire barrier penetration seal program to the NRC. A preliminary submittal was made to the NRC on Nnvember 1, 1989. The licensee made a final submittal to the NRC on February 1, 1990.
4 3.0 [ VALUATION A detailed evaluation of the September 17, 1987 submittal was performed which included comparino the plants penetration seal design details against tested details within specific test reports.
In addition, the test reports themselves were r m -ewed to determine if the test results would substantiate an adequate fire n -ng of each subject penetration seal. As a result of this review, a number of specific questions relating to docurentation were raised, such as appropriate references of test reports on the detail drawings.
None of these issues were considered significant in nature and were resolved in subsequent responses to RAls by the licensee. What was considered by the NRC to be of concern, was that a number of plant details did not directly correspond to tested deteils, in discussions with the licensee, it became apoarent that
" engineering judgement" had been applied to determine that plant details similar to tested details were p.widered adequate. While this type of approach had been found to t,e acceptable at other utilities, in this case there did not 4
appear to be a formal program in place which established evaluation criteria
and a basis for acceptabi b y.
After evaluation of licensee responses to the RAls, it became evident that a site visit would be necessary to establish the acequacy of the penetration seal program.
A site yisit was conducted in October of 1989 to verify sample penetration seal installations and supporting qualificatisn documentation. During this inspection, it was determined that a sig.11ficant number of penetration seals at the^ plant might not have been originally evaluated as to their adequacy.
However, the licensee did have an ongoing program to review all of the l
penetration seals within barriers required to satisfy Appendix A to APCSB 9.5-1 end Appendix R to 10 CFR 50.
At the tire of the inspection, the licensee demonstrated the tracking method used for penetration seals. Tracking consisted of maintain.ing a data base identifying all of the penetration seals of concern and including information such as size, type, reference to a tested de. ail and also reference to a fire barrier drawing which located the penetration in the plant. The fire barrier drawings were reviewed and found to be detailed and a valuable tool for tracking and maint&ining penetration seals.
In additten, all of the Technical Specification fire barriers in the plant were clearly marked. This was found to be extremely helpful in quickly determining what penetrations were of concern in the field, following review of the tracking method, the licensee discussed the as-built seal review.
Because the licensee was aware that adequate documentation was not available to substantiate the rating of installed penetrations, they were performing a 100%
review of installed Technical Specification penetrations. This review consisted of comparty installed penetration seal designs with designs for which test documentada existed and verifying that the tested d: sign qualified as a 3-hour rated seal. The comparisons being performed included 'he following parameters:
size of the sealed opening, size, quantity and proxtnty of penetrating items, orientation of the seal in the barrier, seal material and depth and barrier construction.
If each of these items for the installed seal was determined equivalent to the tested detail, the installed penetration was declared acceptable and documented as such.
If any of these items varied, o engineering evaluation was performed to determine if the devi6 tion could be substantiated and the installed seal declared acceptable.
If the deviation w s found to have a negligible impact on the fire resistive properties of the M a,
then no further analysis was performed.
If it was determined that tne deviation could have an affect on the seal rating, then further stvalu tion wa!
t conducted. This additional evaluation was intended to : determine if certain existing features would allow for a seal design of lesser rating.
Items incked at in this review included such issues as the presence of additional fire sed material in the installed penetration, review of additional fire test reports l
containing similar designs, low combustible loading in Ce area of the seal.
l automatic suppression and detection in the area of the seal, and available manual suppression capabilities. Complex configurations of seals and building design were also reviewed for the effect on required seal rating.
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After review of these items, it was determined if the seal could be considered adequate and, if so, it was so documented.
If not, an order to rework t' teal was submitted. All new seals were reviewed prior to their installation to avoid a reoccurrence of the same situation of unsubstantiated seals.
After review of this program, the NRC determined that the process of penetration seal review being implemented by the utility was acceptable and was definitely an improvenent in the program f rom that found in the previous inspection. Several concerns did rwain at the completion of the inspection.
Although it was found that the elenents of the penetration seal program were found to be adequate, the documentation of the overall program was found to be lacking, which made it difficult to audit both by the NRC and within the u tility. To address this, the licensee agreed to prepare a description of the penetration seal program and provide this to the NRC. This description was provided to the NRC on February 1,1990, and was found to be adequate. The remaining concern was that a number of seals were yet to be reviewed and their adequacy documented. At the time of the inspection, approximately 50% of the seals of concern had been reviewed. The licensee was requested to provide a commitment for completion of the review program. Within their response of February 1,1990, the licensee committed to completing the review of 100% of the Technical Specification seals by December 31, 1991.
While this is thought to be a considerable period of time for this task, it is understood that many of the seals are fully adequate in their existing state and are simply lacking their documentr+1on.
Also, any seals which are currently known to be deficient woulc equire compensatory fire watches per the Technical Specifications. Therefore, the December 31, 1991 date is considered acceptable.
4.0 C0h'.LUS10N Based on a review of information provided in referenced submittals and during l
site visit, the penetration seal program for ANO 182 was found to be adequate:
l Completion of a 100% review by December 31, 1991, is considered acceptable.
1 Dated:
August 7, 1990 l
l Principal Contributor:
D. Notley, SPLB 1
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