ML20052G129
| ML20052G129 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 05/10/1982 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | Dietch R SOUTHERN CALIFORNIA EDISON CO. |
| Shared Package | |
| ML13326A678 | List: |
| References | |
| GL-81-12, LS5-82-5-20, LSO5-82-05-020, LSO5-82-5-20, TAC-48143, NUDOCS 8205140335 | |
| Download: ML20052G129 (3) | |
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GECEryga 3 Bb b DISTRIBUTION gj7ggp May 10, $2 Docket RDiggs mc p
NRC PDR RFerguson Local PDR VBeneroya Docket No. 50-206 cu
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ORB Reading TBarnhcrt (4)
LS05-82-05-020 DEisenhut TWambach l
Glainas ORw l
ORAB HSmith Mr. R. Dietch, Vice President WPaul son Nuclear Engineering and Operations DCrutchfield Southern California Edison Company OELD 2244 Walnut Grove Avenue OI&E Post Office Box 800 ACRS (10)
Rosemead, California 91770 OPA (Clare Miles)
Dear Mr. Dietch:
SEPB
SUBJECT:
EXEMPTION REQUEST - FIRE PROTECTION RULE SCHEDULAR REQUIREMENTS l
OF 10 CFR 50.48(c) - SAN ONOFRE NUCLEAR GENERATING STATION UNIT NO. 1 The Fire Protection Rule, (10 CFR 50.48) published on November 19, 1980, became effective on February 17, 1981, and required the results of certain i
l tasks to be submitted to the Nuclear Regulatory Commission (NRC) by March 19,1981. By letter dated March 19, 1981 as supplemented November 9,1981 you applied for exemption from some of these schedular requirements of 10 CFR 50.48(c). The exemption request related to the l
time allowed to complete a reassessment of the fire protection features at your plant for conformance to the specific requirements of Section III.G l
of Appendix R to 10 CFR 50; to evaluate the difference determined for each area; and to design modifications to meet the requirements or provide a justifiable basis by means of a fire hazards analysis for an exemption from j
such requirements.
For reasons as stated in your exemption request, you l
requested additional time to complete the above reassessments, evaluations l
and designs.
The Commission has granted your exemption request in part as described in the enclosed exemption (Enclosure 1).
You requested that the date for submittal be extended until approximately six months after the completion of the Systematic Evaluation Program. The Commission has granted an extension until July 1,1982. This date is based upon the response of all the licensees with regard to the time needed to perform the reassessment 49g required and the redesign of plant features if necessary. All but a few 67p\\\\
licensees indicated submittal dates prior to July 1,1982, and many have
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f already made their submittals. On this basis, we cannot find that your d
proposed schedule exhibits your best effort in meeting the requirements of 10 CFR 50.48(c) and Appendix R to 10 CFR 50. Therefore, in the judgment 4h of the Cornission, the time elapsed from November 19, '980, when the Fire Protection Rule was published, until July 1,1982, allows adequate time for you to complete your submittal.
If the NRC determines that your response is not complete, as defined in the exemption, on July 1,1982, you will be found in violation of 10 CFR 50.48(cM5).
Such 4_yiplatiqn Wil] be a conin tinuing one and a civi' penalty may be imposed for each day the violation OF FICE )
gg 8205140335 020510 l-PDR ADOCK 05000 anc ronu ais tio soi wcu o243 OFFICI AL R ECOR D C,OPY umomnm
Mr. R. Dietch May 10,1982 The exemptian is being forwarded to the Office of the Federal Register for publication.
, provides a rewording of the request for information included with generic letter 81-12. This rewording is the result of meetings with representative licensees who felt that clarification of the request would help expedito responses.
It does not include any new requests and, there-fore, will not adversely affect licensees' ability to respond to generic letter al-12. pmvfdes information regarding our criteria for evaluating exemption requests from the requirements of Section III.G.2 of Appendix R.
Sincerely, Original signed by Darrell G. Eisenhut, Director Divis.f o_n of Licensing Office of Nuclear Reactor Regulation
Enclosures:
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Mr. R. Dietch May 10,1932 CC Charles R. Kocher, Assistant General Counsel James Beoletto, Esquire Southern California Edison Company Post Of fice Box 800 Rosemead, California 91770 David.R. Pigott Orrick, Herrington & Sutcliffe 600 Montgomery Street San Francisco, California 94111
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Harry B. Stoehr San Diego Gas & Electric Company P. O. Box 1831 San Diego, California 92112 Resident Inspector / San Onofre NPS c/o U. S. NRC P. O. Box 4329 San Clemente, California 92672 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego San Diego, California 92101 l
Cal'ifornia Department of Health ATTN:
Chief, Environmental Radiation Cs ntrol Unit Radioldgical Health Section 714 P Street, Room 498 Sacramento, California 9S814 U. S. Environmental Protection Agency Region IX Office ATTN:
Regional Radiation Representative 215 Freemont Street San Francisco, California 94111 l
Robert H. Engelken, Regional Administrator Nuclear Regulatory Commission, Region V 1450 Maria Lane
'a'alnut Creek, California 94596 I
ENCLOSURE 1 n
1 NUCLEAR REGULATORY COMMISSION In the Matter of
)
SOUTHERN CALIFORNIA EDIS0N COMPANY AND SAN DIEGO GAS AND ELECTRIC
-)
COMPANY
)
Docket No. 50-206
)
(San Onofre Nuclear Generating
)
Station Unit 1),
)
EXEMPTION I.
The Southern California Edison Company (the licensee) is a holder of Provisional Operating License No. DPR-13 which authorizes operation of the San Onofre Nuclear Generating Station. Unit 1 (the facility). The license provides, among other things, that it is subject to all rules, regulations and Orders of the Commission now or hereafter in effect.
The facility is a pressurized water reactor located in San Diego County, California.
II.
On November 19, 1980, the Commission published a revised Section 10 CFR 50.48 and a new Appendix R to 10 CFR 50 regarding fire protection features of nuclear power plants (45 FR 76602).
The revised.Section 50.48 and Appendix R -
became effective on February 17, 1981.
Section 50.48(c) established the schedules for satisfying the provisions of Appendix R.
Section III of Appendix R-contains fifteen subsections, lettered A through 0, each of which specifies requirements for a particular aspect of the fire protection features at a nuclear power plant.
One of these fifteen subsections III.G., is the subject
of this exemption request.
III.G. specifies detailed requirements for fire pro ection of the equipment used for safe shutdown by means of separation and barriers (III.G.2).
If the requirements for separation and barriers could not be met in an area, alternative or dedicated safe shutdown capability, independent of that area and equipment in that area, was required (III.G.3.).
Section 50.48(c) required completion of all modifications to meet the provisions of Appendix R within a specified time from the effective date 'of th.is fire protection rule, February 17, 1981, except for modifications to provide alternative or dedicated safe shutdown capability. These latter modifications (III.G.3.) require NRC review and approval. Hence, Section 50.48(c) requires their completion within a certain time after NRC approval.
The date for submittal of design descriptions of any modifications to provide alternative or dedicated safe shutdown ' capability was specified as March 19, 1981.
By letter dated March 19, 1981, as supplemented November 9,1981, Southern California Edison Company requested an exemption from 10 CFR 50.48(c) with respect to the requirements of Section III.G. This request would extend the deadline for submittal of plans and schedules for a safe shutdown capability, including design descriptions of modifications needed to satisfy Section III.G.3, from March 19, 1981 to approximately six months after completion of the l
Systematic Evaluation Program.
When this Fire Protection Rule was approved by the Commission, it was understood that-the time required for each licensee to re-examine those pre-viously-approved configurations at its plant to determine whether they meet the requirements of Section III.G of Appendix P. to 10 CFR 50 was not well known and would vary depending upon the degree of conformance.
For each
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item of non-conformance that was found, a fire hazards analysis had to be performed to determine whether the existing configuration provided sufficient fire protection.
If it did, a basis had to be formulated for an exemption request.
If it did not, modifications to either meet the requirements of Appendix R or to provide some other acceptable configuration, that could be justified for an exemption, had to be designed. Where fire protection features alone could not ensure protection of safe shutdown capability, alternative or dedicated safe shutdown capability had to be designed as required by Section III.G.3. of Appendix R.
Depending upon the extensiveness and number of the areas involved, the time required for this re-examination, reanalysis and redesign could vary from a few months to a year or more.
The Commission decided, however, to require one, short-term date for all licensees in the interest of ensuring a best-effort, expedited completion of compliance with the Fire Protection Rule, recognizing that there would be a number of licensees who could not meet these time restraints but who could then request appropriate relief through the exemption process. Licensees for 44 of the 72 plants to which Appendix R applies (plants with an operating license issued prior to January 1,1979) have requested such schedular relief.
The licensees for the remaining 28 plants made submittals to meet the schedular requirements of 50.48(c).
All of these submittals, however, were deficient in some respects.
In general, much of the information requested in a generic letter (81-12) dated February 20, 1981, to the licensees of all 72 plants, was not provided.
Therefore, additional time is being' used to compl,ete.those submittals also.
I I I '.
Amendment 44 to Provisional Operating License No. DPR-13, supported by the staff's Fire Protection Safety Evaluation Report (FPSER) for San
.Onofre Unit 1 dated July 19, 1979, predated issuance of the revised 10 CFR 50.48 and Appendix R.
This amendment and FPSER approved the deferral of-the implementation of certain fire protection modifications to the completion i
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of the Systematic Evaluation Program (SEP).
In approving the schedular requirements of the revised 10 CFR 50.48.- the Commission decided that I
implementation of the fire protection modifications should not be deferred to the SEP.
By letter dated. March 19, 1981, Southern California Edison.
stated that with the exception of providing alternative or dedicated safe shutdown capability per Section III.G of Appendix R, it was probable that each of the fire protection items could be implemented in accordance with the required schedules in the revised 10 CFR 50.48. The licensee has informed us that these modifications are scheduled to be completed during the current outage which began on February 27.,19E 2.
As stated previously, the licensee's supplemental. application dated November 9,1981, requested an exemption from 10 CFR 50.48(c) that would adjust the deadline for submission of required information regarding safe shutdown capability for San Onofre Unit 1 to approximately six months after completion of SEP.
None of the other ' plants in the SEP have req'uested a " '
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schedular delay subsequent to the issuance of the revised 10 CFR 50.48 that s
is linked to complett'on of the SEP. All but a few licensees have indicated submittal dates prior to July 1,1982, and many have already made their o
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submittal s.
On this basis, the Ccmmission cannot find that Soethern balifornia Edison's proposed schedule exhibits a best ef-fort in meeting the requirements of 10 CFR 50.48(c) and Appendix R to 10 CFR 50. There-fore, in the judgment of the Commission, the time elapsed from November 19, 1980, when the Fire Protection Rule was published, until July 1,1982, allows adequate time for the licensee to complete the submittal. Accordingly, a schedular exemption until July 1,1982 is the subject for consideration.
IV.
Prior to the issuance of Appendix R, San Onofre Unit 1 had been reviewed against the criteria of Appendix A to the Branch Technical Position 9.5-1 (BTP 9.5-1).
The BTP 9.5-1.was developed to resolve the lessons learned from the fire at Browns Ferry Nuclear Plant.
It is broader in scope than Appendix R, formed the nucleus of the criter.ia developed further in l
Appendix R and in its prest.nt, revised form constitutes the section of the Standard F.eview Plan used for the revi,ew of applications for construction permits and operating licenses'of new plants. The review was completed by the NRC staff a,nd its fire protection consultants and a Fire Protection Safety Evaluation (FPSER) was issued. A few items remained unresolved. Further discourse between the licensee and the NRC staff resulted in resolution of these items as doc 6 tiented in Supplemen,t No.1 to the FPSER dated February 4, 1981. The licensee has completed most of the fire protection modifications l
and has indicated that the remaining modifications not associated with alternative or dedicated shutdown capability are scheduled to be completed
- d rirg the current outage which began on February 27, 1982.
In addition, as stated in our FPSER, the licensee has taken several measures to pro-vide alternate shutdown capability in the interim by the installation of an additional source of offsite power, modifications to the station' air system, provisions for isolation capability of affected control systems, and development of station procedures.
Therefore. San Onofre Unit 1 has been upgraded to a high degree of fire protection already a.nd the extensive reassessment involved in this request for additional time is to quantify, in detail, the differences between what was recently approved and the specific requirements of Section III.G to Appendix R of 10 CFR 50.
Based on the above considerations, we find that' the licensee has com-pleted a substantial part of the fire protection features at San Onofre Unit 1 in conformance with the requirements of the Fire Protection Rule and is applying significant effort to complete the. reassessment of,any remaining modifications which might be necessary-for strict conformance with Section III.G.
We find that because of the already-coppleted upgrading of these facilities, there is no undue risk to the health and, safety of the public involved with continued operation until the completion of this reassessment on July 1,1982.
Therefore, an exemption should bE granted to allow such time for completion, t
l However, because we have found that most submittals.of this reanalysis to date from other licensees have not been complete; that is, not all of the information requested by Generic Letter 81-12 dated February 20, 1981, was provided, we are A
adding a condition to this exemption that requires all such information to be submitted by the date granted.
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n V.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12,, an exemption is authorized by law and will not endanger life or property or the common defense and security and is otherwise in the public interest and hereby grants the following exemptions with respect to the requirements of Section III.G of Appendix R to 10 CFR 50:
(1) The date, March 19, 1981, for submittal of plans and schedules to achieve compliance as required by 150.48(c)(5) is extended to July 1,1982; and (2) The date, March 19, 1981, for submittal of design descriptions of alternative or dedicated shutdown systems to comply with Section III.G.3, as required by 550.48(c)(5) is extended to ' July 1,1982.
Provided that the following condition is met:
The design description of alternative or dedicated shutdown systems to comply with Section III.G.3., as required by 650.48(c)(5) shall include a point-by-point response to each item in Section 8 of to Generic Letter 81-12 dated, February 20,1981, and to each item in Enclosure 2 to Generic Letter 81-12, dated February 20, 1981.
If the licensee does not meet the above condition, the licensee will be found in violation of 10 CFR 50.48(.c) even though the submittal may be made within the time' limit granted by the exemption.
If such a violation occurs, imposition of a civil penalty will be considered under Section 234 of the Atomic Energy Act, as amended. Such a violation will be a continuing one beginning with the date set in the exemption for submittal and terminating when all inadequacies are corrected.
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8-A delay in the determination of inadequacy by the staff, caused by the work-load associated with reviewing all of the submittals falling due near the same time, will not relieve the licensee of the responsibility for completeness of the subnittal, nor will such delay cause any pen ~alty that may be imposed to be mitigated.
The NRC staff has determined that the granting of this exemption will not result in any significant environmental impact and that, pursuant to '
10 CFR 51.5(d)(4) an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with this action.
FOR THE NUCLEAR REGULATORY COMMISSION MM Harold R. Denton, Director Office of Nuclear Reactor Regulation Dated at Bethesda, Maryland this 10th day of May,1982.
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CLARIFICATION OF GENERIC LETTER Op February 20, 1981, generic letter 81-12 was forwarded to all reactor licensees wi.th p.lants licensed prior to January 1,1979. The letter restated the require-ment of Section 50.48 to 10 CFR Part 50 that each licensee would be required to reassess areas of the plant where cables or equipment including associated
. non-safety circuits of redundant trains of systems necessary to achieve and maintain hot shutdown conditions are located to determine whether the require-ments of Section III.G.2 of Appendix R to 10 CFR 50 were satisfied.
Additionally, Enclosure I and Enclosure 2 of the generic letter requested additional
.infonnation concerning those areas of the plant requiring alternative shu' tdown t
capability. Section 8 of Enclosure 1 requested information for the systems, equipment and procedures of alternative shutdown capability and Enclosure'2 defined associated circuits and requested information concerning associated circuits for those areas requiring alternative shutdown.
In our review of licensee submittals and meetings with licensees, it has become apparent that the request for information'should be clarified since a lack of clarity could result in the submission of either insufficient or e,xcessive f
information. Thus, the staff has rewritten Section 8 of Enclosure 1 and of the February 20,1981, generic letter. Additionally, further clarification of the definition of associated circuits'has been provided to aid in the reassessments to determine compliance with the requirements of Sections III.G.2 and III.G.3 of Appendix R.
In developing this= rewrite we.have l
The attached considered the cornuent of the Nuclear Utility Fire Protection Group.
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rewrite of the Enclosures contains no new requirements but merely attempts to clarify the request for additional information.
9
2-4.icense,es who have not responded to the February 20, 1981 generic letter, may. choose to respond to the enclosed request for information.
Since the s
enclosed request for information is not new, but merely clarification of our previous letter, responding to it should not delay any submittals in
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progress that are based upon February 20, 1981 letter.
Licensees whose response to the February 20, 1981 letter, has been fc5nd : incomplete resulting in staff identifications of a major unresolved item (iie., associated circuits),
may choose to respond to pertinent sections of the enclosed request for infor-mation in order ~to close open items (i.e., open item for. associated circuits,
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use rewrite of Enclosure 2).
If additional clarification is needed, please contact the staff Proje'ct flanager for your plant.
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n REWRITE OF SECTIO!i 8 REQUEST FOR ADDITIO!iAl. ItiFORMATI0fi
. The following is. a rewrite of the staff's request for additional infomation
,concerning design modification to meet the requirenents of Section III.G.3 of Appendix R.
The fcilouing contains no new requests but is merely a rewording of Section 8 of Enclosure 1 of the February 20, ~ 1981 generic letter.
1.
Identify those areas of the plant that will not meet the requirements of Section III.G.2 of Appendix R and, thus alternative shutdown will be providek
, or an exemption from the requirements of Section III.G.2 of Appendix R will' be provided. Additionally provide a statetent that all other areas of. the plant are or will be in compliance with Section III.G.2 of Appendix R.
For each of th'ose fire areas of the plant requiring an alternative shutdown system (s) provide a complete set of responses to the following requests for each fire area:
a.
List the system (s) or portions thereof used to provide the shutdown capability with the loss of offsite power.
I b.
For those systems' identified in '.'la" for which alternative or dedicated shutdown capability must be provided, list the equipment and components of the normal shutdown system in the fire area and identiff the functions of the circuits of the normal shutdown system in the fire. area (power to what equipment, control of what components and instrumentation). Describe the system (s) or portions thereof used to provide the alternative shutdown capability for the fire area and provide a table that lists the equipment l
and components of the alternative shutdown system for the' fire area.
l a
For each alternative system identify the function of the new circuits bein.g provid d.
Identify the location (fire zone) of the.
alternative shutdown equipment and/or ci.rcuits that bypass the fire area and verify that the alternative shutdown equipment and/or circuits are separated from the fire area in accordance with Secticn III.G.2.
Provide drawings of the alternative shutdown system (s) wh'ich highlight any c.
conne_ctions to the normal sh'utdown systems (P& ids for piping ano corr.ponen'ts, _
elementary wiring diagrams of electrical cabling).. Show' the electrica'l
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location of all' breakers for power cables, and. isolation devices for control and instrumentation circuits for ti.a alternative shutdown systems
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for that fire area'. 9
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d.
Verify that changes to safety systems will not degrade safety systems; (e.g., new isolation switches and control switches should meet design criteria and standards in the FSAR for electrical' equipment in the sy' stem that the switch is to be installed; cabinets that the switclies, are to be mounted in should also meet the same criteria (FSAR) as other safety
- r. elated cabinets and panels; to avoid inadvertent isolation from the
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control room, the isolation switches siiculd be keylocked or alarmed in the control room if in the " local" or " isolated" position; periodic l
n checks should be made' to verify that the switch is in the proper position for
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normal operation; and a ' single transfer switch or other new device should not be a source of a fai ure which causes loss of reaunaant safety 6 l
systems).
er Verify that licensee procedures have been or will. be develo' ed which describe the p
i tasks-toievperfomed to effect the shutdown method.
Provide a summary
,0f these procedures outlining operator actions.
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Verify that the manpower required to perform the shutdown. functions using the procedures of ei. as well as to provide fire brigade members to fight the fire is available as required by the fire brigade technical spect-fichtions.
9 Provide a commitment to perform adequate acceptance tests of the alter-na tive shutdown capability.
These tests should verify that:
equipment operates from the local control station when the. transfer or isolation switch is.placed in the " local" position and' that the equipment cannot be operated,from1the control room; and that equipment operates from'the control room but cannot be operated 'at the loca.1 control station when
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.the transfer isola'ti5n switch is in the " remote" posit: ion.
h.
Provide Technical Specifications of the surveillance requirements and limiting conditions for operation for that equipment not already '
covered by existing Technical Specifications.
For. example, if new isolation and control switches are added to a shutdown system,
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the existing Technical Specification surveillance requirement {e,should!bg.
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j Ebe supplemented to verify system / equipment functions from the alternate i
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shutdosr station at testing intervals consistent with the ' guidelines of Regulatory Guide 1.22 and IEEE 338.
Credit may be taken for other existing tests using group overlap test concepts.
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Foi new equipment comprising the alternative shutdown capability,' verify
~ that the systems available are adequate to perform the necessary shut-down function.
The functions required should be based on previous analyses, if possible (e.g., in the FSAR), such as a loss of normal ac power or shutdown on Group 1 isola, tion (BWR).
The equipment required for the alternative capability should be the'same or equivalent to that relied on in the above. analysis.
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j, Verify.that repair procedures for cold shutdown systems are developed -
and materialfor repairs is maintained on' site.
Provide a summary of these procedures and, a: list of the material needed for repairs.
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D A-
SAFE'SHDTDOWN CAPABILITY _
The following discusses the requirements for. protecting redundant and/or 2
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The alternative equipment needed for safe shutdown in the event of a fire.
' equirements of Appendix R address hot shutdown equipm r
The followi.ng.y.equirements aise apply to cold snutdown
" free of fire damage.
equipment if tha licensee elects to denonstrate that the. equipment' is to be Appendfx R does allow.re'pairable damage to cold shutdown free of fir,e. damage.
ecutoment.
..e Us'ing the requirements of Sections III.G and III.L of Appendix R, the capa--
bility'to achieve hot shutdown must exist given a fire in any area of the Section'III.G plant in conjunction with a loss of offsite power for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
of Appendix R provides four methods for ensuring that the hot shutdown capa-liility is protected from fires. The first thre'e options as defined in Section III.G.2 provides methods for protection from fires of equipment needed for hot shutdown:
Redundant systems including cables, equipment, and associated circuits 1.
may be separated by a three-h'our fire rated barrier; or, Redundant systems.tncluding cables, equipment and associated circuits may l'
2.
l be separated by a horizontal distance of more the.n 20 feet with no inter-In addition, fire detection and an autom'atic fire i
vening combustibles.
suppression system are required; or, Redundant systems including cables, egoipment and associated circuits may 3.
In addition, fire detectors by enclosed by a one-hour fire rated barrier.
and an automatic fire suppression system are required.
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2 The last option as defined by Section III.G.3 provides an alternative shutdown
- capability to the redundant trains damaged by a fire.
4.
Alternative shutdown equipment must be independent of the cables, equip-ment and associated circuits of the redundant systems damaged by th'e fire.
Associated Circuits ~of Concern The following discussion provides A)'a definition of associated circuits for Appendix R consideration, B) the guidelines for protecting the safe
- shutdown capability from the fire-induced failures of associated circuits and C) the in-formation required by the staff to review associated circuits. The definition of associated circuits has not changed from the Februa'ry '20,1981 generic letter; -
but is merely clarified.
It is important to note that our interest is only with those circuit (cables) whose fire-indeed failure could effect shutdown.
T'he guidelines for protecting the safe shutdown capability from the fire-induced failures of associated circuits are not reouirements_. These guidelines should be used only a.s guidancs when needed. These guidelines do not' limit the alter.
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nativss available to the licensee for protecting the shutdown capability.
All proposed methods for protection of the shutdown capability from fire-induced failures will be evaluated by the staff for acceptability.
A.
Our concern is that circuits within the fire area,will, receive fire damage yhich can affect shutdown capability and thereby prevent post-fire safe i
shutdown. Associated Circuits
- of Concern are defined as those cables (safety N 1ated, non-safety related, Class 1E, and non-Class 1E) that:
- The definition for associated circuits is not exactly the sam,e as the definition presented in IEEE-384-1977.
1.
Have a physical separation less than that required by Section III.G.2 of Appendix R,.and; 2.
Have one of the following:-
a common power source sith the shutdown equipment (redundan.t or a.
alternative) and the power source is not electrically protected from the circuit of concerp by, coordinated breakers, fuses, or similar devices (see diagram 2a), or b.
a connection to circuits of equipment whose spurious operation,
would adversely affect the shutdown capability (e.g., RHR/RCS isolation valves, ADS valves, PORVs, steam generator atmospheric dump valves, instrumentation, steam bypass, etc.) (see diagram 2b), or a connon enclosure (e.g., raceway, panel, junction) with the shutdown c.
cables (redundant and alternative) and, (1) are not electrically protected by circuit breakers, fuses or simi-lar devices, nr (2) will ailow propagation of the fire into the common enclosure, (see diagram 2c).
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EXAMPLES OF ASSOCIATED CIRCUITS OF CONCERN i
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E.up,,,c d a o,e,g uimas The area. barriers shown above. meet 6-sus the apprcpriate sub-paragraphs (a-f) oper.Ld coulet affec/.
of section III.; -2 of Apper. dix R.
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Diagram 2A Diagram 28 Diagram 2C s
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4 The following guidelines are for protecting the shutdown capability from B.
fire-induced failures of circuits (cables) in the fire area.
The guidance provided below for interrupting devices applies only to new devices installed to provide electrical isolation of associated circuits of concern, or as The shutdown capability part of the alternative or dedicated shutdown system.
may be protected from the adverse effect of damage to associated circuits of concern by the following methods:
Provide protection.between the associated circuits of concern and 1.
the shutdown circuits as per Section III.G.2 of Appendix R, or For a comon power source case of associated circuit:
2.
a.
Provide load fuse / breaker ^(interrupting devices) to feeder fuse / breaker coordination to prevent loss of the redundant or To ensure that the following alternative shutdown power source.
coordination criteria are m,et the 'fol]owing should apply:
(1) The associated circuit of concern interrupting devices '
(breakers or fuses) time-overcurrent trip characteristic foi all circuits faults should cause the interrupting device to interrupt the fault current prior to initiation of a trip of any upstream interrupting device which will cause a loss of the common power source,
,(2) The power source shall supply the necessary fault current for sufficient time to ensure the proper. coordination without loss of function of the shutdown loads.
The acceptability of a particular interrupting device is considered demonstrated if the following criteria are met:
g (i) The interrupting device design shall be factory' tested to verify overcurrent protection as designed in accordance w'ith
. the applicable UL, ANSI, or NEMA standards.
(ii)
For low and medium voltage switch' gear (480 V an[above) circuit breaker / protective relay periodic testing shall demonstrate that the overall coordination scheme' remains within the limits specifi.ed in the design criteria.
This testing may be performed as a series of overlapping tests.'
(iii)
Molded case circuit breakers shall peridically be manually exercised and inspected to insure ease of operation. On a rotating refueling outage basis a sample of these breakers shall be tested to determine that breaker drift is within
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that allowed by the design criteria.
Breake6should_be tested in accordance with an accepted QC testing methodology
.such as MIL STD 10 5 D.
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Fuses when used as interrupting devices do not require periodic testing, due to their stability, lack of drift, and high reliability. Administrative controls must insure that replacement fuses with ratings other,than those selected for proper coordinating are not accidentally used, b.
For circuits of equipment and,/or components whose
- spurious' operation would affect the capability to s'afely shutdown:
y (1) provide a means to isolate the equipment and/or companents from the fire area prior to the fire (i.e., remove power cables, open
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circuit breakers); or (2) provide electrical isolation that prevents spurious operation.
Pot,,ential isolation devices include breakers, fuses, ampli-fiers, control switches, current XFRS, fiber optic couplers, relays and transducers; or (3) provide a means to detect spurious operations and then proce-dures to defeat the maloperation of equipment -(i.e., closure o.f the block valve if PORY spuriously operates, opening of the breakers to remove spurious operation of safety injection);
For common enclosure cases of associated circuits:
c.
(1) provide appropriate measures to prevent propagation.of the fire; and (2) provide electrical protection (i.e., breakers, fuses or similardevices)
C.
We recognize that there are different approaches which may be used to reach the same objective of determining the interaction of associated circuits with shutdown systems. One approach is to start with the' fire area, identify what is in the fire area, and' determine. the interaction between what is in the fire area and the shutdown systems which are outsfde the fire area. We have entitled this approach, "The Fire Area A second approach which we ' ave named "The Systems Approach" h
Approach."
would be to define the shutdown systems around a fire area and then determine
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those circuits that a e located in the fire area that are associated with the shutdown sys. tem. We have prepared two sets of requests for information, one for each approach.
The licensee may choose to. respond e
to either set of requests depending on the approach selected by the licensee.
FIRE AREA APPROACH
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For each fire area where an citernative or dedicated shutdown method, in accordance with Section III.G.3 of Appendix R is provided, the following infomation is required to demonstrate that ass.ociated circuits will not preverit operation or cause maloperation of the alternative or dedicated sh'utdown method:
a.
Provide a table that lists all the power cables in the fire area that connect to the same power supply of the. alternative or dedicated shutdown method and the function of each power cable listed (i.e., power for RHR pump).
b.
Provide a table that lists all the cables in the fire area that were considered for possible spurious operation which would adversely affect shutdown and the function of each cable listed.
c.
Provide a table that lists all the cables in the f. ire area that share a common enclosure with circuits of the alternative or dedicated shutdown systems and the function of each cable listed.
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d.
Show that fire-induced failures (hot shorts, open circuits or shorts to ground) of each of the cables listed in a, b, and c will not prevent operation or cause maloperation of thb alternative-or dedicated shutdown method.
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For each cable listed in a, b and c where new electrical isolation has been provided or modification to existir.g electrical isolation has been made, provide detailed electrical schematic drawings that show how each cable is isolated from the fire area.
SYSTEMS APPROACH 1.
For each area where an alternative or dedicated shutdown method, in accordance with Section III.G.3 of Appendix R is provided,.the following information is required to demonstrate that associated circuits will not prevent operation or cause maloperation of t'he'-
alternative or dedicated shutdown method:
Descr.e the methodology used to assess the potential of associated e
a.
circuit adversly affecting the alternative or dedicated shutdown.
The description of the methodology shoul.d include the ~ methods used to identify the circuits which share a comon power. supply.
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or a como,n enclosure.with the alternative or dedicated shutdown system and the circuits whose spurious operation would affect i
shutdown. Additionally, t'he description should include the l
methods used to identify.if these circuits are associated circuits '
1 of concern due to 'their location in the fire area.-
l b.
Provide a table that lists all associated circuits of concern l
located in the fire area.
l c.
Show that fire-induced failures (hot shorts, open circuits or shorts to ground) of each of the cables listed in b will not prevent operation or.cause maloperation of the alternatite.or dedicated shutdown method.
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d.
For each cable listed in b where new electrical isolation has been
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provided, provide detailed electrical schematic drawings that show how each cable is isolated from the fire area.
c Provide a location at the site or other office,s where ali the' e.
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tables.and drawings generated by this methodology approach for the associated circuiti; review may'be audited to verify,the
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information provided above.
HIGH-LOW PRESSURE INTERFACE For either approach chosen the following concern dealing with high-low-pressure interface should be addressed.
2.
The residual heat removal system is generally a low pressure system that interfaces with the high pressure primary coolant system. To.
preclude a LOCA through this interface, We requi.re compliance with the recommendations of Branch Technical Position RSB 5-1. - Thus, the interface most likely consists of two redundant and independent motor operated valves. These two motor o#erated valves and their associdted cables may be subject to,a single f. ire hazard.
It is our concern that this single fire could cause the two valves to open resulting in a fire initiated LOCA through the high'-low pressure system interface. To assure that this interface and other high'-low pressure interfaces are adequately protected from the effects of a single fire, we require the following information[
a.
Identify each high-low pressure interface that uses redundant electrically controlled devices'(such as two series motor operated valves) to isolate or preclude rupture of any primary coolant b undary.
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b.
For each set of redundant valves i~dentified in a.,
verify the redundant cabling (power and control) have adequate physical separation as required by Section III.G.2 of Appendix R.
c.
For each case whe.re adequate separation is r.ct previded, shm: thct fire induced failures (hot short, open circuits or short to ground) of the cables will not cause maloperation and result in a LOCA.
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CRIT'ERIAFOREVAEUATIrlG EXEMPTI0fl5 TO SECTI0A III G OF APPErlDIX R
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OF 10 CFR PART 50 Paragraph 50.48 Fire Protection of 10 CFR Part 50 requires that all
, nuclear power plants licensed prior to January 1,1979 satisfy the requirements of Section III.G of Appendix R to 10 CFR Part 50.
It also requires that alternative fire protection configurations, previously approved by an SER be reexamined for compliance with the requirements of Section 111.3.
Section III.G is related to ' fire protection features for ensuring that systems and associated circuits used to achieve and maintain safe shutdown.are free of fire damage.
Fire protection configurations' must eithe.r meet the. specific require-mints of Section. III.G or an alternative ' fire protection configuration '
must be,idstified by a fire hazard analysis.
The general criteria for accepting an alternative fire protection configur-ations are the following:
The alternative assures that one train of equipment necessary to achieve hot shutdown from either the control room or emergency control stations is free of fire damage.
The alternative assures that fire damage to at least one train of equipment necessary to achieve cold shutdown is limited such that it can be repaired within a reasonable time (minor repairs'with' components stored on-site).
Fire retardant coatings are not used as fire barriers.
Modifications required to meet Section III.G would.not enhance fire protection safety above that provided by either existing or proposed alternatives.
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Modifications requir-ed to meet Section III.G would be detrimental to overall facility safety.
Because of the broad spectrum cf potential configurations for. which exemptions may be requested, specific criteria that account for all of the parameters that are important to fire protection and consistent with safety requirements.of all plant-unique configurations have not'been devel oped.
However, our evaluations of deviations from these require-ments in our grevious reviews and in the request's for III.G exemptions received to date have identified some recurring configura.tions for which specific criteria have been developed.
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2-Section III.G.2 accepts three methods of fire protection.
A passive 3-hour fire barrier should be used where possible.
Where a fixed barrier cann'ot be installed, an automatic suppression system in ceabination with a fire barrier or a separation distance free of ccmbustibles is used if the configurations of systems to be protected and in-situ combustibles are such that there is reasonable assurance.that the protected systems will survive.. If this latter condition is not met, alternative shutdown capa-bility is required and a fixed suppression system installed in the fire area.of concern, if it contains a large concentration of cables.
It is essential to remember that these alternative requirements are'not deemed to be equivalent.
However, they provide adequate protection for those configur~ations in which they are ac'cepted.
When' the fire protection fe'at'ures of each fire. area are evaluated, the whole system of such features must be kept in perspective. The defense-in-depth principle of fire protection programs is aimed at achieving an adequate. balance between the different features.
Strengthening any one can compensate in some measure for weaknesses, known or unknown in.others.
The adequacy of fire protection for any particular plant safety system or area is determined by analysis of the effects of postulated fire relative to maintaining the ability to safely shutdown the plant and minimize radio-active releases to the environment'in the event of a fire. During thes,e evaluations it is necessary to consider the two-edged nature of fire protection features recognized in General Design Criterion 3 namely, fire protection should be provided consistent with other safety considerations.
An evaluation must be made for each fire area for which an exemption is requested.
During these evaluations, the staff considers the following
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parameters:
'A.
Area Description walls, f,loor, and ceiling construction ceiling height room volume ventilation congestion B.
Safe Shutdown Capability number of redundant systems in area
- whether or.not system or equiment is required for hot shutdown type of equipment / cables involved repair time for cold shutdown equipant within 'this area separation between redundant ccaponents and i~n-situ concentration of combustibles
~ alternative shutdown capability
C.
Fire Hazard Analysis type and configuration of combustibles in area quantity of combustibles ease of ignition and propagation heat release rate potential transient and installed combustibles
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suppression damage to equipment whether the area is continuously manned traffic through the area accessibility of the area D.
Fire Protection Existing or Committed fire detection systems fir ~e extinguishing systems
. ho.s,e station / extinguisher radiant heat shields
'A specific description of the fire protection features of the configuration is required to justify the compensating features of the alternat'.ve. Low 1
fire loading is not a sufficient basis for granting an exemption in areas where there are cables.
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If necessary, a team of. experts, incluav.g a fir ~e protection engineer, will visit the site to determine the existing circumstances.
This visual inspection is also considered in the review process.
The. majority of the III.G exemption requests received to date are being denied because they lack specificity.
Licensees have not identified the extent of the exemption requested, have not provided a technical basis
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For the request and/or have not provided.a specific description of the alternative. We expect to receive requests for exemption of the following nature:
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Fix'ed fire. barriers less than 3-hour rating.
2.
Fire barrier without an automatic fire suppression system.
'Less than 20 feet separation of cables with fire propagation 3.
retardants (e.g., coatings, blankets, covered trays) and an automatic suppression system.
For large open areas with few components to be protected and few in-situ 4.
combustibles, no automatic' suppression system with separation as in Item 3.above.
No fixed suppression in the contr$1 foom.
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No fixed suppression in areas without a large concentration of cables for which alternative shutdown capability has been provide.d.
Our fire research test program is conducting tests to provide information that will be useful to determine the boundary of acceptable conditions for fire protection configurations which do not include a fire rated barrier.
Basedondehiationsrecentlyapproved,specificcriteriaforcertain recurring configurations are as follows:
" Fire Barrier Less than Three Hours
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This barrier.is a wall, floor, ceiling or an enclosure which sepaiates one fire area from another~.
Exemptions may be granted for a lower rating (e.g., one hour or two' hours) where.the fire loading is no more than 1/2 of the barrier rating. The fire rating of the barrier shall'be no less than one hour.
Exemptions may' be granted for a fixed barrier with a lower fix rating supplemented by a water curtain.
An Automatic Suppression System With Either One Hour Fire Barrier or 20-Foot Separation This barrier is an enclosure which separates those portions of one division which are within 20 feet of the redundant division.
The suppressant may be water or gas.
Exemptions may be granted for configurations of redundant systems which hav~e compensating features.
For example:
A.
. Separation distances less than 20 feet may be deemed acceptable.where:
Fire propagation retardants (i.e., cable coatings, covered trays, 1.
conduits, or mineral wool blankets) assure that fire propagation
.through in-situ combustibles will not occur or will be delayed sufficiently to ensure adequate time for detection and' suppression.
l 2.
Distance above a floor level exposure fire and below ceiling assures l
that redundant systems will not be simultaneously subject to an una.cceptable temperature or heat flux.
B.
The ommission of an automatic suppression system may be deemed acceptable
.here:
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Distance above a floor level exposure fire and below ceiling assures that redundant systems.will not be simultaneously subject to an unacceptable temperature 'or heat flux.
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The fire' area is required to be manned continuously by the provisions in the Technt. cal Specifications.
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PEi:P.ITE $F ' SECTIO" P F.E00EST FOR ADDIT:0! A!. I!iFOR"ATIO!i The following is. a rewrite of the staff's request for additional infomation
, concern' ng design modification to meet the requirements of Section III'.G.3 of i
[ppendix P..
The folioving contains no new requests but is merely a. rewording of Section 8 of Enclesure 1 of the February 20,'1931 generic letter.
5 FrCi 1.
Identify those areas of the plant ~ that will' not meet the requirements of ~
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Section III.G.2 of Appendix R' and, thus afternative shutdown will be proy'ideh c:+-=
, or an exemption from the requirements of Section III.G.2 of Appendix R will' be provided. Additionally provide a statement that all other areas of, the plant are or will be in compliance with Section III.G.2 of Appendix R.
For.each of those fire areas of the plant requiring art alternative shutdown systen(s) provide a complete set'of responses to.the following requests for
'eac'h fire area:
List the system (s) or portions thereof used to provide the sh'ut,down a.
capability with the loss of. offsite power.
b."For those systems" identified in."la" for which alternative or dedicated '
- shutdown t.ap' ability must be provided, list the equipment and components
- of the normal shutdown system in the fire area and identif9 the functions of 'the circuits of the normal shutdown system in the fire area (power to what equipment, control of what components and instrumentation).
Des'cribe.
the system (s) or portions thereof used to provide the alternative shutdown capabi.Lity for the fire area and provide a table th'at lists the equipment
'and components of the alternative shutdown system for the' fire area.
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2 For each alternative system identify the function of the new circuits being provided.
Identify the location (fire zone) of the alternative shutdown equipment and/or circuits that bypass the fire area and verify that the alternative shutdown equipment and/or circuits are separated from the fire area in accordance with Section III.G.2.
Provide drawings of the alternative shutdown jystem(s) which highlight any c.
co,nnections to the normal sh' tdown systems (P& ids for piping ana components, u
elementary wiring diagrams of electrical cabling). Show the electrical
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location of all breakers for power cables, and. isolation devices for control.and instrumentation circuits for the alternative shutdown systems for that fire area.
d.
Verify that chitnges 'to safety systems will not degrade safety systems; (e.g., new isolation sw' itches and control switches should meet design criteria and standards in the FSAR for electrical equipment iri the system that the switch is to be installed; cabinets that t.he switches are to be mounted in should also meet the same criteria (FSAR) as other safety related cabinets and panels; to avoid inadvertent isolation from the control room, the isolation switches should be keylocked or alamed in the control room if in the." local" or " isolated" position; periodic
' checks should be made' to verify that the switch is in the proper position for normal operation; and a single transfer switch or other new device should not be a source of a failure which causes loss of reounaant safety-6 system 5).
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Verify that' licensee procedures have been or will, be develo' ped which describe the tasks to be perfomed to effect the shutdown method.
Provid'! a-summary of these pro ~cedures-outlining operator a'ctions.
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Verify that the manpower required to perform the shutdown functions using the procedures of e:. as well as to provide fir ~e brigade members to fight the fire is available as required by the fire brigade technical speci-fications.
9 Provide a commitment to perform adequate acceptance tests of the alter-native shutdown capability.
These tests should verify that:
equipment operates from the local control station when the. transfer or. isolation
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switch is placed in the local" position and that the equipment cannot be operated from the control room; and that equipment operates from~ the
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control room but cannot be operated at the local control station when the transfer' isolation switch is in the " remote" position.
h.
Provide Technical Specifications of the surveillance requirements and limiting conditions for operation for that equipment not already covered by existing Technical Specifications.
For example, if new isolation and control switcheis are added to a shutdown system, the existing Technical Specification surveillance requirements should be supplemented' to verify system / equipment fun ' ions from the alternate shutdown station at testing intervals consistent with the guidelines of
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Regulatory Guide 1.22 and IEEE 338.
Credit may bet taken for other existing tests using group overlap test concepts.
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i For new equipment comprising the alternative shutdown capability, verify that the systems available are adequate to perform the necessary. shut-p down function.
The functions required should be based on previous analyses, if possible (e.g., in the FSAR), such as a loss of normal ac power or shutdown on Group 1 isola, tion (BWR).
The equipment required for the alternative cai: ability should be th'e same or equivalent to that relied on in t'hc above analysis.
j Verify.that repair procedures for cold shutdown systems are developed and matirial for repairs is maintained on site.
Provide a summary of these procedures and a': list of the material needed for repairs.
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