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ENCLOSURE 1 CHEMICAL ENGINEERING BRANCH 5AFETY EVALUATION REPORT LACK OF THREE-HOUR FIRE RATED PENTRATION SEALS IN CABLE SPREADlhG RODM CEILING / CONTROL HOOM FLOOR ASSEMBLY BO5 TON EDI5ON COMPANY p!LGRIM NUCLEAR POWER STATION DOCKETNO.50-Zy
1.0 INTRODUCTION
By letter dated December 8,1987 (BECo 87-196), the licensee provided information v
and their evaluation to resolve Item A on page 4 of Region I Inspection Report 87-39 which pertains to an exemption granted from the requirements of Appendix R to 10 CFR 50 to provide automatic suppression in the control room. Approval of the exeeption was based in part, on a 3-hour fire rating for the ceiling / floor assembly between the Cable Spreading Room (CSR) and the Control Room (CR). The December 8, 1987 letter acknowledged that some penetration seals in the CSR j
ceiling /CR floor assembly do not meet the 3-hour fire rating, and that other seals are so located that the bottom surface cannot be inspected.
2.0 EVALUATION 1
The licensee presented several technical points supporting their position that I
the existing penetration seals are satisfactory and that upgrading these seals is not required.
Combustible loading in the CSR is primarily cable insulation, most of which is equivalent to the fire resistance criteria of IEEE Standard 383. Most of the cable. Including all of the non-fire-e retardant cable, has been coated with a fire-retardant material.
Alternative safe shutdown systems that are independent of both the 1
Control Room and the CSR have been installed. The alternative safe shutdown systems, complete with detailed emergency operating procedures, are available for use in the event of a fire in either I
or both rooms, and er.ceed the requirements of Appendix R. both in redundancy and in plant functions provided.
i Although the Control Room and the CSR are listed as separate Appendix R fire areas, a major fire in either area would disable the safe shutdown components in the other, regardless of the fire barrier between thee.
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The Control Room floor /CSR ceiling is a twelve-inch-thick slab of l
concrete. Other than some penetaation seals and a small amount of uncoated structural steel, the concrete floor is capable of acMeving a three-hou rating.
Structural stal under the Control Room floor /CSR ceiling has been covered with a Nre resistant coating at all accessible points; the remaining uncoata' steel has been found acceptable in an SER.
I Although some of tle penetrations are not three-hour rated, they all provide a level of protection comensurate with the barrier's Appendix R requir ments. Therefore, the Control Room floor /CSR i
ceiling provides adequate fire protection to the Control Room and the CSR.
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Due to congestiot under the CSR ceiling, upgrading the penetration i
l seals would require disruption of many circuits, some of which are l
safety-related, with extensive impact on time and resources and a I
potential negativs irpact on safety.
l About 250 holes (typically 6. inch diameter) fom the penetrations of iiterest.
i All of the openings were ini:ially sealed with a combination of fire et tardant foam material, mineral fiber and cemeatitious grout. This was found acceptable by the staff. The upper surface of all of the penetration seals has been visually examined by the licensee and found to be in satisfactory condition.
The bottom surface of approximately 10". of these penetration seals cannot be I
inspected due to cable congestion. However, the remaining seals have been inspected and determined to be satisfactory.
In addition, the licensee perforwed a full discharge test of the total flooding Halon suppression system in the CSR following inst 411ation. No difficulty was experienced in reaching and maintaining the de:ign concentrations of Halon in the room. This would not have been the case if signi/icant leaks existed in the enclosing barriers, thus, providing indirect j
evidence that the penetration seals are intact.
Ti.e staff agrees with the Itcensee's posittoa, that considering the corbination of conditions that exist in the plant, it is not necessary in the interests of fire protection to upgrade the uninspectable penetration seals in the CSR ceiling /CR floor to 3-hour fire resistance rating.
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3.0 CONCLUSION
On the basis of the above Evaluation, we conclude that the existing penetration seals in the Cable Spreading Room ceiling / Control Room floor assembly are catisfsetory and do not need to be upgraded to a full 3-hour fire resistance rating. We also reaffirm the 1981 exemption from the requirements of Appendix R to 10 CFR 50 for autoratic suppressica in the Control Room even though the exemption was originally granted, in part, on the basis of 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire rating of the CSR ceiling /CR floor assembly, l
c' ENCLOSURE 2 SALP INPUT FROM THE CHEMICAL ENGINEER!hG BRANCH FOR I
P!LGRIM NUCLEAR POWER STATION A.
Licensing Activities 1.
Management involvement in Assuring Quality The presentation of facts concerr-ng the penetration seals in the CSR ceiling /CR floor assembly was concise, fully stated and complete.
The letter was a high quality product that required no additional contacts by the staff with the licensee.
Rating:
1 I
2.
Approach to Resolution of Technical Issues from a Safety Standpoint The approach to resolution of this issue was technically sound, straight-l forward, and complete.
Rating:
1 3.
Responsive to NRC Initiatives The licensee'.
atcar on this issue was complete and required no questions I
from the staff.
Rating:
1 4.
Stafitng(IncludingManagement)
Rating N/A 5.
Reporting and Analysis of Reportable Events l
Rating: N/A 6.
Training and Qualification Effectiveners Rating:
N/A 7.
Overall Rating for Licensing Activity in Functional Area Rating:
1 1