ML20214D111
| ML20214D111 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 11/14/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20214D069 | List: |
| References | |
| NUDOCS 8611210363 | |
| Download: ML20214D111 (3) | |
Text
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
i i
f n:vq'o UNITED STATES
~g E
NUCLEAR REGULATORY COMMISSION o
WASHINGTON, D. C. 20555 k.....
SAFETY EVALUATION RY THE OFFICE OF NilCLEAR REACTOR REGULATION RELATING TO APPENDIX R EXEMPTION REQUEST PHILADELPHIA ELECTRIC COMPANY I.
[
PEACH BOTTOM NUCLEAR POWER STATION, UNITS 2 AND 3 DOCKET NOS. 50-277/278 Introduction In our Fire Protection Safety Evaluation, we requested the licensee to provide a detailed description and evaluation of electrical and mechanical
(
penetration seals. By letter dated February 21, 1980 the licensee provided additional information concerning the penetration seals. We revie'wed the information and in our Fire Protection Safety Evaluation, we stated that the information was not adequate to resolve the open item.
B.y letter dated November 24, 1980, we informed the licensee that penetration seals Safety Evaluation open items 3.1.7 and 3.2.8(2) remained open issues and final resolution and acceptability of the penetration seals would be predicated upon compliance with the provisions of Section III.M of Appendix R to _10 CFR Part 50. By letter dated March 20, 1981, the licensee committed to examine and upgrade as required in accordance with Section III.M of Appendix R to 10 CFR Part 50 penetration seals in barriers whose integrity is required to ensure safe shutdown capability. By letter dated May 27, 1983, the licensee indicated that some penetration seals would not be upgraded to be in accordance with Section III.M as previously committed and requested an exemption from Section III.M from providing noncombustible material in penetration seals. By letters dated July 72, 1983, September 16, 1983, December 2, 1983, February 10, 1984 September 17, 1984, January 16, 1985 and September 24, 1985, the licensee provided additional information to support the exemotion request.
Exemption Request By letter dated May 27, 1983, the licensee requested an exemption from Section III.M of Appendix R to 10 CFR 50 to the extent it requires penetra-tion seals which utilize only non-combustible materials.
Discussion In response to the new fire protection rule Appendix R to 10 CFR Part 50, the licensee committed to upgrade all penetration seals in barriers used to separate redundant safe shutdown equipment which the staff had previously 8611210363 861114 fDR ADOCK 05000277 PDR w-
questioned. Ilpon further investipation of this open item the licensee determined that approximately 6,750 seals in 341 fire barriers needed to be upgraded, and in some cases, removing existing penetration seals and replacing them with fire rated seals would not be practical. By letter dated May 27, 1983, the licensee indicated that instead of replacing penetration seals in accordance with Section III.M of Appendix R in some cases, existing seals which contain combustible materials would be modified and the modified seal configuration would be tested in accordance with ASTM E 814-81 " Standard Method of Fire Tests of Through Penetration Fire Stops." The licensee conducted a series of tests at the National Gypsum Company Research Center, Buffalo, New York. The Factory Mutual Research Corporation witnessed the test and prepared the following test reports:
1.
" ASTM E 814-81 Fire Endurance and Hose Stream Tests on Wall Penetration Fire Stops Design WP 694 for Philadelphia Electric,"
November 4, 1983 5
2.
" ASTM E 814-81 Fire Endurance and Hose Stream Tests on Wall Penetration Fire Stops Design WP 713 for Philadelphia Electric,"
February 16, 1984 3.
" ASTM E 814-81 Fire Endurance and Hose Stream Test on Floor Penetration Fire Stops Design FC 350 for Philadelphia Electric,"
March 14, 1984 The licensee has submitted test reports to support the use of combustible materials in the penetration seals.
Evaluation l
The technical requirements of Section III.M of Appendix R to 10 CFR Part 50 are not met because the subject penetration seals are not entirely con-structed of noncombustible materials.
The staff was concerned that where combustible materials are used in pene-tration seals, such materials may be ignited and transmit a fire from one fire area to another. Test results have also indicated'that penetration seals in which combustible material is encased between noncombustible material are susceptible to somewhat earlier failures if the noncombustible material has become cracked and a fire produces a positive pressure on the hot side of the seal.
e The' test results submitted by the licensee indicated that seine of the modified penetration seal designs passed the ASTM E 814 test for a 3-hour fire resistive temperature rating. The licensee, however, had not committed to use only seals that were tested and approved.
In addition the licensee indicated that some penetration seals which passed the fire endurance test failed the hose stream test. By letter dated September 24, 1985 the licensee stated that the
(
redesigned penetrations seals used in fire rated barriers will have passed I
both the fire endurance and hose stream tests of ASTM E 814-81. All penetration seals installed in fire rated barriers will be refurbished in accordance with the modified penetration seals which have been tested and approved.
Based on the licensee's comitments and the tests conducted on the redesioned penetration seals, we find that the modified seals which contain combustible materials will provide adequate performance under fire conditions and provide an equivalent level of protection to that required by Section III.M of Appendix R.
._...-_.m___._
e 3'
- g.
Conclusi n
+
Rased on our evaluation, we find the penetration seals which contain combustible materials will provide an equivalent level of protection to the technical requirements of Section III.M;of Appendix R.. Therefore, the exemption should.be granted.
4 Principal Contributor:
J. Stang Dated: November 14, 1986 i
s,"
s 5
\\
4 N
l l
I t,
e
. _ _ _ _ _ _ _