ML18102B504
| ML18102B504 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 08/05/1997 |
| From: | Lochbaum D AFFILIATION NOT ASSIGNED |
| To: | Callan L NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| Shared Package | |
| ML18102B503 | List: |
| References | |
| NUDOCS 9708180101 | |
| Download: ML18102B504 (7) | |
Text
";
, _+0012023320905.S DC Mr. L. Joseph Callan Executive Director for Operations UNION OF CONCERNED SCIENTISTS August 5, 1997 United States Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
FIRE PENETRA noN SEAL QUESTIONS
Dear Mr. Callan:
728 P02 RUG 05 '97 18:17 Per my FAX dated August l, 1997, and our telephone conversation on that date, I am respectfully submitting questions on fire penetration seals on behalf of Mr. Paul Gunter of the Nuclear lnfonnation
& Resource Service and UCS. Our intention was to submit questions to you on Monday, August 4, 1997, but wo were unable to meet our schedule.
Mr. Gunter and l would like to arrange a public meeting with you to discuss the issues raised by these questions. The purpose of such a meeting would be to reach a common understanding of the fire penetration seal concerns and agree upon a course of action to resolve these concerns.
While our fire penetration seal concerns apply to the Salem Generating Station, we recognize that they are unlikely to be resolved prior to the restart of that facility. Since the concerns also apply to many nuclear power plants which are currently operating, we concede lhat the concerns need not be a restart constraint for Salem Unit 2.
We look forward to pursuing resolution of these concerns with you.
Sincerely,
~a David A. Loch aum Nuclear Safety Engineer cc:
Paul Gunter NJRS 9708180101 970806 PDR ADOCK 05000311 F
PDR I
I Waehlngton Olllce: 1818 P Street NW Sultu 310
- Waah~gton DC 20031M495
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- FAX: !510-843-3785
+0012023320905.S DC e 728 P03 NIRS I UCS Fire Penetration Seal QuestJons NON COMBUSTIBILITY OF FIRE PENE'l'AA TION SEALS AUG 05 '97 18:17 August !5, 1997 Page 'I of 6 10 CFR Part 50, Appendix R Subpart III.M, "Fire barrier cable penetration seal qualification,"
states:
"Penetration seal designs shall utilize only noncombustible materials and shall be qualified by tests that are comparable to tests used to rate fire barriers."
10 CFR Part 50, Appendix A, General Design Criterion 3, "Fire protection," states:
"Noncombustible and heat rosistant materials shall be used wherever practical throughout the unit, particularly in locations such as the containment and control room."
Guidance on the NRC staff's intention for "wherever practical" appear in Standard Review Plan Section 9.3.l, "Fire Protection Program," Rev. 3, July 1981:
"The following specific criteria provide information, recommendations, lllld guidance and in general describe a basis acceptable to the staff that may be used to meet the requirements of §50.48, GDC 3 lllld 5;
- a.
Branch Technical Position (BTP) CMEB 9..S-1 as it related to the design provisions given to implement the fire protection program.
1 "Openings through fire barriers for pipe, conduit, and cable trays which separate fire areas should be sealed or closed to provide a fire resistance rating as least equal to that required of the barrier itself. Penetration designs should utilize only noncombustible materials and should be qualified by tests.
11 According to NRR Office Letter No. 2, 11Standard Review Plans for Safety"Evaluations, dated August 12, 1975,... tho SRPs [Standard Review Plans] represent the integrated result of the hundreds of conscious choices made by the staff and by the nuclear industry in developing design criteria and design requirements for nuclear power plants. Now that the plans are published and in use, they represent the most definitive basis available for specifying NRC's interpretation of an 'acceptable level of safety' for light water reactor facilities."
The NRC staff is presently revising the Standard Review Plan. In the draft version of SRP 9.5. l (Standard Review Plan Section 9.5.1, "Fire Protection Program, Draft Rev. 4, April 1996}, the staff proposes to expand "wherever practical" to include the fire barriers themselves in addition to the fire penetration seals:
"The following specific criteria provide information, recommendations, and guidance and in general describe a basis acceptable to the staff that may be used to meet the requirements of 10 CFR §50.48, GDC 3 and 5:
. +0012023320905 ~S DC 728 P04 NIRS I U CS Fire Penetration Seal Questions RUG 05 '97 18:17 August 5, 1997 Page 2 of 6
- a.
Branch Technical Position (BTP) SPLB 9.S-1 as it related to the design provisions given to implement the fire protection program."
110penings through fire barriers for pipe, conduit, and cable trays which separate fire areas should be sealed or closed to provide a tire resistance rating as least equaJ to that required of the barrier itself. Stntctural fire barriers (e.g. walls, floors, ceilings),
including penetration designs, should utilize only noncombustible materials and should be qualified by tests in accordance with the applicable sections of NFPA 251 and ASTM Ell9."
Mr. William H. Ruland of NRC Region I staff indicated that the 1916 version of the Branch Technical Position attached to the 1981 and 1996 SRP 9.5. l does not contain the fire penetration seal noncom bustibility requirement.
QI What is the historical backgJOund on NRCs analyses used to develop and indude
noncombustible materials" in its guidance documents and regulations?
The NRC staff has recently been resolYing a comparable issue involving Thermo-lag fire barrier material which is combustible. In a letter from Conrad E. McCracken, Chief - Plant Systems Branch, Nuclear Regulatory Commission, to Alex Marion, Manager - Technical Division, Nuclear Energy Institute, "Thermo-Lag 330*1 Combustibility Evaluation Methodology Plant Screening Guide," dated March 13, 199S, the NRC staff maintained the position that noncombustible materials must be used:
"On the basis of its combustibility tests and review, the staff concluded that Thermo-Lag 330-1 fire barrier material has combustible characteristics similar to those of other nuclear power plant combustible materials, such as fire-retardant plywood and cable jackets. The staff also concluded that the NEI method does not provide a level of fire safety equivalent to that specified by existing NRC fire protection regulations and guidelines. Therefore, the staff will not accept the use of the NEI guide to justify the use of Thermo-Lag materials where noncombustible materials are specified by NRC fire protection requirements or to assess the combustibility hazards presented by Thermo-Lag materials."
Thus, noncombustibility of fire penetration seals appears to be an implicit requirement of 10 CFR §50.48 and Appendix A GDC 3 and to be an explicit requirement of Appendix R III.M.
- Q2 How does the NRC &taff reconcile the guidance in SRP 9.5.1 and the position taken on Thenno-lag with its recent claims that fire penetration seal11 need not be ooncombustible?
- +0012023320905.S DC e 728 P05 NIRS I UCS Fire Penetration Seal Questions APPLICABILITY OF APPENDIX R, SUBPART mM RUG 05 '97 18:18 August 5, 1997 Page 3 of 6 In a letter from Chairman Jackson to Senator Bidcn dated July 29, 1997, the NRC explained that Appendix R Subpart lll.M only applied to nuclear plants licensed prior to January 1, 1979, which had an open item on fire b~rrier penetration seals at that time.
Q3 What are the nuclear plants for which Appendix R Subpart ID.M applies?
The NRC staff has recently claimed that noncombustibility is a requirement of Appendix R, Subpart III.M, but not of 10 CFR §S0.48 and Appendix A GDC 3. If this position is correct, then noncombustible fire penetration seals are only prohibited at some, but not all, older nuclear plants. Newer nuclear plants (i.e., those licensed after the Browns Feny firo of 1975) can use combustible fire penetration seals according to NRC claims.*
Q4 h it credible that the NRC's fire protection requirements would really bave become less rigorous for nuclear power plants licensed !fig the Browns Feny tire?
" +0012023320905.S DC 728 P06 NIRS I UCS Fire Penetration Seal Questions RUG 05 '97 18:18 August 5, 1997 Page 4 of 6 TECHNICAL BASJS FOR NONCOMBUSTmLE FIRE PENETRATION SEAL MATERIAL In a letter from Chainnan Jackson to Senator Biden doted July 29, 1997, the NRC explained that "the NRC staff plans to propose a rule change that would eliminate the Appendix R requirement that penetration seal materials be noncombustible since there is no technical basis for it."
ln SECY-96-146, 11Technical Assessment of Fire Barrier Penetration Seals in Nuclear Power Plants,'
1 the NRC staff recommended that "the material noncombustible criterion be removed from Appendix Rand the SRP.
11 Q.5 Since the NRC staff ha§ not yet changed the mies and since licensees have not yet applied for or been granted deYiations/cxemptions from these requiremeou, is the NRC staff'll stated intention to change a regulation really an acceptable (e.g. legal) substitute for the sulemaking process in which the public bas at least an opportunity to register opposition?
The technical basis for the NRC stuffs concern about combustible fire penetration seal material is explicitly detuiled in a safety evaluation attached to a letter from Robert M.
Bemero, Director - Division of BWR Licensing, Nuclear Regulatory Commission, to Edward G. Bauer, Jr., Vice President & General Counsel, Philadelphia Electric Company, "Exemption from Appendix R to 10 CFR.50 Concerning Penettation Seals and Fire Detection," dated November 14, 1986:
"The staff is concerned that whcte combustible materials are used in penetration seals, such materials may be ignited and transmit a fire from one fire area to another.'
1 Q6 Was the NRC staff wrong to believe in 1986 that there !!!!! a technical basis for noocombus1ible fire penetration seal material? Or is the NRC staff wrong to believe now that there is nQ technical basis?
Infonnation gathered during the fire endurance test of RTV silicon foam perfonned by the Underwriters Laboratory of Canada in 1996 indicate that hydrochloric acid (HCL) is a byproduct from the burning foam. The videotape of this test clearly indicated thick smoke from the burning foam on the non-fire side of the simulated penetration.
Q7 Does the NRC staff have any infonnation which indicates that equipment, particularly electrical components, on the unex1Jo1ed side of a fire penetntion seal with silicon foam will not be adversely affected by the byproducts, including soot and uh? Would not the use of combustible fire penetnltion seal material introduce a failure mode (i.e., create an unreviewed safety question) that is not present with noncombustible fire penetration seal materiPis?
In the NRC Office of Investigation's Official Transcript of Proceedings of the Investigative Interview of Hitoshi Takab11Si, Senior Marketing Supervisor Fire Stop_ Product Line, Dow Coming, dated August 24, 1994, Mr. Takahasi stated that in the 1984 to 1987 time frame he
+0012023320905 ~S DC 728 P07 NIRS I UCS Fire Penetration Seal Questions RUG 05 '97 August 5, 1997 Page 5 of 6 responded to a situation at the Peny Nuclear Power Plant where RTV silicon foam had been
abused". Mr. Takahasi testified that "abused" meant "thut some air pocket behind had broke out seal where the hydrogen gas kind of accumulated which was seeped out and exploded later on type situation." In the DuraSystems videotape of the three hour fire endurance test conducted by the Underwriters Laboratory of Canada, it is stated that hydrogen gas generated by the two part RTV silicon foam causes the material to "snap" and produce a friction fit.
Q8 Is NRC away of this event or other events where a fire penetration seal can actually become the ignition source?
18:18
+0012023320905.S DC 728 P08 NIRS I UCS Fire Penetration Seal Questions COMPLEXITY OF LICENSING BASES RUG 05 '97 18:19 August 5, l 997 Page 6 of 6 In a letter from Chairman Jitekson to Senator Biden dated July 29, 1997, the NRC explained that Appendix R Subpart lll.M only applied to nuclear plants licensed prior to January 1, 1979, which had an open item on fire barrier penetration seals at that time.
It seems fair to conclude that each operating nuclear power plant has unique licensing requirements based on the regulations in effect at the time and the conditions under which the licenses were issued.
Q9 How can the NRC sWf de'Velop backlit analyses for all operating plants or even a subgroup of operating plants if e'Veey plant has unique licensing bases? How can the owners groups and NEl p~pare and advocate "generic" industcy positions on licensing issues?
In the NRC Office of Investigation's Official Transcript of Proceedings of the Investigative Interview of Hitoshi Takahasi, Senior Marketing Supervisor Fire Stop Product Line, Dow Coming, dated August 24, 1994, Mr. Takahasi stated:
"there are so many variables in the firo tost itself (ASTM E 118). first of all, design you claim you passed first time around may not necessarily be the single design you subjected to the test and qualified for that design. You could run 100 tests, literally speaking. Literally you can run 100 tests for the same design. If one passes you can qualify that design. So was the situation. What my contention was you are stretching the ability of the product way too thin and it might be almost 50/50 chances of passing or faHing, especially if you are careless in doing the installation that might cause some failure."
The Individual Plant Examinations (IPEs) prepared for Salem and other nuclear plants implicitly assumed I 00% success of the fire barriers, including fire penetration seals, in preventing a fire in one fire zone/area from affecting an adjacent fire zone/area.
Q 10 B~ed on infonnation that fire endurance testing conducted under laboratory conditions ix not 100% successful and licensee event reports and NRC inspection reports indicating that fire penetration seals are periodically found in a degntded or nonconfonning condition, are the IPEs nonconservatively detennining fire risk?