ML993190099
| ML993190099 | |
| Person / Time | |
|---|---|
| Site: | Nuclear Energy Institute |
| Issue date: | 10/29/1999 |
| From: | Beckner W Technical Specifications Branch |
| To: | Jennifer Davis Nuclear Energy Institute |
| References | |
| Download: ML993190099 (19) | |
Text
October 29, 1999 Mr. James Davis, Director Operations Department Nuclear Energy Institute 1776 I Street, N. W.
Suite 400 Washington, DC 20006-3708
Dear Mr. Davis:
Enclosed is a summary of our joint NRC/Technical Specifications Task Force (TSTF)
Owners Group meeting at the Nuclear Regulatory Commission in Rockville, Maryland, on October 13 and 14, 1999. Should the TSTF have any comments or questions, please do not hesitate to contact me on 301-415-1161 or by e-mail at wdb@nrc.gov.
Sincerely, original Signed By William D. Beckner, Chief Technical Specifications Branch Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Project No. 689
Enclosure:
As stated cc:
Those on enclosed Attendees List DISTRIBUTION:
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UNITED STATES NUCLEAR REGULATORY COMMISSION Z
WASHINGTON, D.C. 20555-0001 October 29, 1999 Mr. James Davis, Director Operations Department Nuclear Energy Institute 1776 I Street, N. W.
Suite 400 Washington, DC 20006-3708
Dear Mr. Davis:
Enclosed is a summary of our joint NRC/Technical Specifications Task Force (TSTF)
Owners Group meeting at the Nuclear Regulatory Commission in Rockville, Maryland, on October 13 and 14, 1999. Should the TSTF have any comments or questions, please do not hesitate to contact me on 301-415-1161 or by e-mail at wdb@nrc.gov.
Sincerely, William D. Beckner, Chief Technical Specifications Branch Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Project No. 689
Enclosure:
As stated cc:
Those on enclosed Attendees List
Nuclear Energy Institute cc:
Mr. Ralph Beedle Senior Vice President and Chief Nuclear Officer Nuclear Energy Institute Suite 400 1776 1 Street, NW Washington, DC 20006-3708 Mr. Alex Marion, Director Programs Nuclear Energy Institute
'Suite 400 1776 1 Street, NW Washington, DC 20006-3708 Mr. David Modeen, Director Engineering Nuclear Energy Institute Suite 400 1776 I Street, NW Washington, DC 20006-3708 Mr. Anthony Pietrangelo, Director Licensing Nuclear Energy Institute Suite 400 1776 1 Street, NW Washington, DC 20006-3708 Mr. Hank Sepp, Manager Regulatory and Licensing Engineering Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, Pennsylvania 15230 Mr. Jim Davis, Director Operations Nuclear Energy Institute Suite 400 1776 1 Street, NW Washington, DC 20006-3708 Ms. Lynnette Hendricks, Director Plant Support Nuclear Energy Institute Suite 400 1776 I Street, NW Washington, DC 20006-3708 Mr. Charles B. Brinkman, Director Washington Operations ABB-Combustion Engineering, Inc.
12300 Twinbrook Parkway, Suite 330 Rockville, Maryland 20852 Project No. 689
TECHNICAL SPECIFICATIONS TASK FORCE MEETING
SUMMARY
October 13 and 14, 1999 Publication of Revision 2 to the Standard Technical Specification The staff notified the Technical Specifications Task Force (TSTF) that Draft Revision 2 files will be posted to the NRC web site by October 20, 1999. An updated matrix table containing all approved travelers and the sections they affect will also be posted at that time. A brief discussion followed describing the staffs experience reviewing the TSTF's comments on the last Draft Revision 2 files posted. The staff agreed to provide the TSTF with a copy of their comment tables and corresponding staff comments. The TSTF agreed to provide a schedule for their review of the October 20 postings at a later date.
Review of Outstanding High Priorty Travelers Highlights of individual traveler discussion follows:
TSTF-348: Jack Foster is the staff reviewer. Status will be provided during the October 14 Owners Group meeting. On October 14, the staff reviewer provided the following: a meeting with the Radiation Protection staff will take place in the near future, at which time a recommendation by the staff will be made.
"* TSTF-350: Status will be provided during the October 14 Owners Group meeting. On October 14, the staff reviewer recommended Approval.
TSTF-051, R.2: The staff noted minor editorial changes and agreed to accept replacement pages to avoid another revision submittal. When the Owners Group meeting reconvened on October 14, the TSTF provided the replacement pages. The staff recommended approval.
"° TSTF-287, R.2: The staff disposition is Modify; a disposition letter, to be transmitted in the near future, will contain the comments associated with this disposition.
TSTF-322, R.1: This is a newly submitted traveler. The staff agreed to review the proposed changes overnight and provide comments on October 14. When the Owners Group meeting reconvened on October 14, the staff noted that the Inserts should further clarify applicability to the Shield Building. The TSTF agreed to submit a revision.
TSTF-052, R.2: This traveler was sent to a technical branch to review putting Appendix J into a program; the Owners Group requested that TSTF-334 be given a higher priority than this traveler. Review of TSTF-334 is scheduled to be complete by October 30, 1999.
"° TSTF-226: Review is still pending. The staff advised the TSTF that these changes would not be incorporated in the Revision 2 publication.
"* TSTF-242: There was some discussion regarding the Completion Time for a Controlled Outage Time (COT). The staff will confer with the technical branch and try to resolve by October 30, 1999.
Enclosure TSTF-320: The staff feels that brackets are not being used consistently, which makes it difficult to interpret. The TSTF agreed to provide a clarification.
TSTF-266, R.2: The staff disposition is Approve; a disposition letter will be transmitted in the near future.
o TSTF-295: This traveler is under review by a technical branch; the staff will try to complete review by October 30, 1999.
0 TSTF-306: The staff had a few questions that were resolved and review will continue; an attempt to complete by October 30, 1999 will be made.
& TSTF-342: Review is still pending.
TSTF-284, R.2: The staff is in the process of compiling a response to the TSTF. An individual discussion between the staff reviewer and the Owners Group Chairmen is scheduled to take place on October 14, 1999.
TSTF-330: Although the TSTF classified this as a high-high priority, NRC management has tasked the BWR Owners Group to present this issue separately because the staff believes an AOT is not the correct method. It does not appear this change will be incorporated with the Revision 2 publication.
TSTF-335: Under technical branch review; the staff will remind the Ice Condenser Task Force of the importance of completing the review so that changes may be incorporated with the Revision 2 publication.
" TSTF-336: Under technical branch review; the staff will remind the Ice Condenser Task Force of the importance of completing the review so that changes may be incorporated with the Revision 2 publication.
"* TSTF-340: The staff found that the TSTF's description was not consistent with the proposed changes and the justification was insufficient. The TSTF agreed to submit a modification.
"* TSTF-017, R.2: The staff recommended approval.
"° TSTF-351: The staff recommended approval.
"* TSTF262: The staff provided some comments to the Owners Group Chairman.
"* TSTF-263: The staff disposition is Modify; a disposition letter, to be transmitted in the near future, will contain the comments associated with this disposition.
"* TSTF-265: The staff disposition is Modify; a disposition letter, to be transmitted in the near future, will contain the comments associated with this disposition.
TSTF-329: The staff recommended approval.
Enclosure
"* TSTF-353: The staff recommended approval.
TSTF-352: The staff requested additional information with regard to changing the time and inconsistent use of brackets.
TSB-016: Although the TSTF rejected the proposed changes because they did not feel it was generic, the staff found seven plants (Byron, Braidwood, South Texas, Ginna, Oconee, Farley, and Ft. Calhoun) that have a need to address this problem (reactor coolant pump restrictions); others (Comanche Peak, Diablo Canyon, Kewaunee, Sequoyah, and Point Beach) have been informed by Information Notice to correct it. The TSTF agreed to look into this matter.
TSB-017: The staff requested an explanation/justification regarding the Westinghouse Owners Group telefax indicating a need for an addition.
TSTF-016, R.1: Status will be provided during the October 14 Owners Group meeting. On October 14, the staff recommended that the TSTF modify as discussed in Attachment 1.
TSTF-036, R.4: New traveler submitted to NRC via letter dated October 6, 1999.
TSTF-198 through -203: Comments from IEEE were received by NRC; Electrical &
Instrumentation & Controls Branch (EELB) comments (on the consensus version) should be received by October 8. NRC will incorporate all comments, route through EELB, and send a Modify to the TSTF, adding a request to also provide Bases.
TSTF-204, R.1: Status will be provided during the October 14 Owners Group meeting. On October 14, Tommy Le provided a handout (Attachment 2), which was discussed. NRC will recommend a modification to supplement the Bases and Reviewer's Note.
TSTF-283, R.2: New traveler submitted to NRC via letter dated October 6, 1999.
"* TSTF-286: TSTF will provide a revision by the end of the week (October 15).
"* TSTF-333: TSTF will provide a revision by the end of the week (October 15).
"* TSTF-037, R.2: Status will be provided during the October 14 Owners Group meeting. On October 14, the NRC recommended approval.
" TSTF-349: NRC staff requested the TSTF to provide additional justification for the proposed change, including a discussion of why not turn on one pump while the other is still running.
This should be addressed in terms of midloop operations, vortexing, air entrainment, pump start and the overall operability of the system.
Enclosure TSTF-284, R.2: The staff provided four examples (Attachment 3) and asked for a distinction. The TSTF offered the following:
0 "Met" refers to acceptance criteria "Performed" is not used as a verb, but in place of "frequency" or to "be current" NRC has additional questions and will correspond with TSTF to make the next revision acceptable.
Adoption of Approved TSTFs by Converted Plants This issue was briefly discussed after which it was decided that further discussion needs to take place.
Future Owners Group Meeting The next Owners Group meeting has been tentatively set for November 18, and December 14 and 15, 1999.
October 14, 1999 Owners Group Meeting When the Owners Group meeting reconvened, the following travelers were discussed:
TSTF-297: Rich Lobel, Plant Systems Branch, joined the meeting to discuss issues regarding proposed changes. The outcome is that he needs to discuss further with the Technical Specifications Branch (TSB) staff, but he feels the recommendation will be to modify the Bases to clarify or better explain the Specification.
TSTF-343: The Technical Branch has made comments, which will be discussed via teleconference next week between Jack Foster, TSB, and Noel Clarkson, CEOG Chairman.
The meeting was adjourned until November 18, 1999.
Enclosure
ATTENDEES LIST NRC/TSTF OWNER'S GROUP MEETING OCTOBER 13 AND 14, 1999 NAME ORGANIZATION_
ADDRESS PHONE #
E-MAIL ID Noel Clarkson Duke Energy Oconee Nuclear Site 864-885-3077 ntclarks@duk (BWOG TSTF) 7800 Rochester Highway e-energy.com
- _Seneca, SC 29679 Harold D.
ComEd/BWOG LaSalle County Station 815-357-6761 harold.d.ponti Pontious, Jr.
2601 North 21S" Road x2231 ousir@ucm.co
._Marseille, IL 61341 m
Tom Weber CEOG-APS Palo Verde Nuclear 623-393-5764 tweber0l@ap Mail Station 7636 sc.com 5801 South Wintersburg Road Tonapah, AZ 85354-7529 Vince Gilbert NEI Suite 400 202-739-8138 ivq@nei.org 1776 I Street, NW Washington, DC 20006-3708 Brian Mann EXCEL/TSTF 301-984-4400 bmann@erols.
corn D. Buschbaum TSTF/WOG TU Electric 254-897-5851 dbuschbl @tu P. 0. Box 1002, M.S. A08 electric.com Glen Rose, TX 76043 Donald Hoffman EXCEL/TSTF 11921 Rockville Pike 301-984-4400 donaldh@exc Suite 100 elsvcs.com Rockville, MD 20852 Joe Birmingham NRR/RGEB NRC 304-4415-2829 ilb4@nrc..ov Tom Dunning NRR/TSB NRC 301-415-1189 tgd@nrc.gov Bob Tjader NRR/TSB NRC 301-415-1187 trt@nrc.qov Bill Beckner NRR/TSB NRC 301-415-1161 wdb@nrc..qov Bob Dennig NRR/TSB NRC 301-415-1156 rld@nrc.gov James Lazevnick NRR/EEIB NRC 301-415-2782
.il@nrc..ov Ed Tomlinson NRR/TSB NRC 301-415-3137 ebt@nrc.Qov Tommy Le NRR/TSB NRC 301-415-1458 nbl@nrc.qov Carl Schulten NRR/TSB NRC 301-415-1192 cssl@nrc.aov Enclosure
ATTENDEES LIST NRC/TSTF OWNER'S GROUP MEETING OCTOBER 13 AND 14, 1999 DOCUMENT NAME: G:\\RTSB\\JOHNSON\\OWNERS GROUP CORRESPONDENCE\\ATTEND.WPD Enclosure NAME ORGANIZATION ADDRESS PHONE #
E-MAIL ID Robert Giardina NRR/TSB NRC 301-415-3152 Craig Harbuck NRR/TSB NRC 301-415-3140 cch@nrc,,qov
Review of TSTF 16, Revision I
-Summary
/.e essential features of TSTF 16 Rev I have already been approved and implemented fir the BWRI4 class. The combination of NRC-02 (previously approved for all designs) and TSTF 16 Rev I comprises a logical whole that meets the technical specification structural/logic rules, It can be improved by making the "no loss of function" premise for CONDITIONS A, B, and C expitcit in the CONDITIONS, and by some additional modifications of the Bases to define "subsystem" as discussed under Bases Improvements. However, concerns expressed about Its efficacy, i.e., quality and timeliness of the process for determining loss of function, are not peculiar to 3.8.9 but relate to how technical specifications work in general. It is reasonable to conclude that the quality and timeliness of determining loss of function will be adequate in the context of 3.8.9 as revised by TSTF 16 Rev 1.
Descriotion of Proposed Changes The following description is based on the markups of "3.8.9 Distribution Systems - Operating" submitted by TSTF as Revision 1 dated 218/96.
The substantive changes are modeled on the BWR/4 Revision 1 STS. For the WOG, BWOG, CEOG, and BWRI6 the proposed change substitutes the phrase "one or more" for the word "one" in CONDITION statements for AC electrical power distribution subsystems, AC vital buses, and DC electrical power distribution subsystems, e.g., from the proposed BWOG STS markup:
"A.
One or more AC electrical power distribution subsystems inoperable."
Changes are shown in bold italics. The REQUIRED ACTIONS and COMPLETION TIMES are unchanged. The language for CONDITIONS A, 8 and C is standard for all PWRs, and essentially the same for both BWR classes with deviations appropriate to the design. The proposed change also standardizes the language for CONDITION E (F for BWR/6) for all designs:
"Two or more electrical power distribution subsystems inoperable that result in a loss of function."
This change is most dramatic for the WOG, which previously was the only OG with phrasing using the concept of trains in this CONDITION, i.e.. As currently in the STS:
"Two trains with inoperable distribution subsystems that result in a loss of safety function."
The related bases are also revised to clarify that for CONDITIONS A, B, and C no loss of function has occurred, in contrast with CONDITION E where loss of function has occurred. The bases are also modified to substitute "one or more" in place of "one" in appropriate locations, but mute importantly the bases are modified to eliminate the constraint that the "one or more",
previously "one", applies to inoperabilities confined to one "train". Thus the bases contemplate ATTACHMENT 1
multiple inoperabilites possibly in both of the redundant portions of the electrical design as long as they do not result in a loss of function. A change is also proposed to substitute fairly standard (for all designs except WOG) basis languag6 in the WOG STS for CONDITION E (F for BWRJ6):
"Condition E corresponds to a level of degradation in the electrical power distribution system that causes a required safety function to be lost. When more than one inoperable electric power distribution subsystem results in a loss of a required function, the plant is in a condition outside the accident analysis. Therefore, no additional time is justified for continued operation. LCO 3.0.3 must be entered immediately to commence a controlled shutdown."
Discussion A succinct summary of how the revised 3.8.9 is supposed to work is provided in the Fermi - 2 DOC for the conversion currently under review:
"fCTS LCO 3.8.3.1 allows restoration times for one division of AC distribution (8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Action a), and one division of DC distribution (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> - Action b), de-energized. ITS 3.8.7 [corresponds to STS 3.8.9] Action A and B allows one 'or more' AC and DC electrical power distribution subsystems to be inoperable for the same times, respectively. Concurrently, however, ITS Action D [corresponds to STS Action E] is also added to require that if two or more electrical power distribution subsystems are inoperable, resulting in a loss of function, enter 3.0.3 immediately. The combination of the 'or more" addition to ITS 3.8.7 Actions A and B, and the addition of Action D, along with ITS LCO 3.0.6 Safety Function Determination Program, ensure that with the loss of any electrical power distribution system no loss of function will occur without appropriate action. This presentation will allow the Action A or Action B Completion Time for a portion of one division to be inoperable, provided these portions do not affect redundant systems required for safe operation. In the event a loss of function exists, ITS Action D will provide actions consistent with the CTS Actions for inoperabilities in both divisions.
Therefore, this less restrictive change will have a negligible impact on safety."
Fermi 2 is converting to the current STS Rev I standard for BWR/4s, a standard that TSTF 16, Rev I seeks to emulate for the other STS NUREGS as part of Revision 2. There are five BWR 4s that have converted so far. Of those, Brunswick, Duane Arnold, and Susquehanna have the "one or more" language. Cooper has "one AC and one DC." Peach Bottom is a mix. It allows "one or more" Unit 3 AC, "one" Unit 3 DC, and "one" Unit 2 AC and DC. Fermi 2 will have the "one or more' language when it is issued. Thus, we have well-established precedent, both generic and plant specific, for allowing the fundamental change proposed by TSTF 16 Rev 1 for one class of plant.
Denial of TSTF 16 Rev 1 must then be based on one of two arguments:
- 1. The "one or more" language is acceptable for BWR/4s, but unacceptable for other designs because........ or
- 2. The "one or more" language is unacceptable for any design, and the STS Rev 1 BWRJ4 should be amended to delete this language.
Previous staff reviews have pursued the second track, with non-acquiescence by the TSTF and internal disagreement, resulting in persistenpe of the status quo for approximately 4 years.
While there are some residual concerns about 3.8.9, mostly having to do with what appears to be a determined effort not to spell out what a "subsystem" is In the Bases, the previous staff objections can be adequately addressed and the proposed change on balance represents an improvement Objection - Total loss of redundancy is explicitly allowed for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> This objection results from focusing on CONDITION A, B, or C without reference to CONDITION E, which must also be evaluated under the hypothesized circumstances, and is more limiting.
Presume that the plant has interpreted "subsystem" to mean a redundant division or train of the "typical 2 train/div" plant, which has been done in practice, e.g., Brunswick. Suppose further that both trains are simultaneously inoperable. CONDITION A, "One or more AC electrical power distribution subsystems inoperable" is true, with REQUIRED ACTION to restore within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
However, all CONDITIONS are operative, and the licensee must determine if CONDITION E is also true, i.e., "Two or more electrical power distribution subsystems inoperable that result in a loss of function." For the simultaneous loss of both divisions of redundancy in power supply, toss of function occurs by definition and recognition of that loss of function would take no more time than the time to make the division operability determinations. So in this case entry into 3.0.3 occurs without any time elapsing in CONDITION A.
In practice, the higher the level at which usubsystem" is defined, the easier it is to determine whether a safety function is lost, sothat the worst safety situation is the easiest to interpret in tech specs, which is what we would hope. The more subtle cases occur where portions of a "division" are considered subsystems, and a more detailed understanding of "support supported" relationships is necessary to determine if a "loss of function" has occurred.
However, the use of "one or more" in 3.8.9 does not raise any new issues with respect to licensee knowledge of these relationships, or the speed with which an operability determination should be made. Assumptions and expectations about these issues underpin the efficacy of all technical specifications as discussed in more detail below. The bottom line in response to this objection is that the postulated two train outage will exist for as long as it takes to make operability determinations, and CONDITIONS A, B and C do not provide a "right" to operate with total loss of redundancy for 8, 2, and 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> respectively.
Objection - TSTF 16 was necessitated by NRC-02 which should not have been approved because: (1) The specification relies on the licensee knowing support-supported system relationships in order to determine loss of function, and (2) there is no explicit time limit for determining loss of function, Relationship of NRC-02 to TSTF 16 Rev I Revision 0 of the improved Standard Technical Specifications was issued September 28, 1992.
Shortly thereafter the NRC staff originated "NRC-02" sometime in January 1993. The change proposed the following language for insertion in 3.8.9 for all vendors:
"Two or more trains, Enter 3.0.3 Immediately with one or more inoperable Distribution subsystems" The need for this change is not evident from the surviving documentation. However, the
"=Standard Technical Specification Change Traveler" that accompanied the above states in the "Executive Summary of Change":
"...a required action rather than 3.0.3" From this it is fair to conclude that since CONDITIONS were only specified for "one" AC vital bus, *one" DC subsystem, "one" AC subsystem the objective was to provide an explicit entry to 3.0.3 for "Two or more" rather than have entry implicit from absence of a CONDITION..
Further, the wording of the CONDITION as cited above supports the interpretation that a "train" consists of one or more "subsystems". If different safety functions are supported by different "subsystems" within each redundant trains, under the above wording it would be possible to satisfy the CONDITION and have to begin shutdown immediately without a loss of safety function. For example, assume the "subsystem" that supplies AC power to LPCI A is inoperable, and the "subsystem" that supplies AC power to Containment Spray B is inoperable:
CONDITION satisfied, enter 3.0.3 immediately. This can be viewed as unnecessarily conservative and undesirable. After all, if the same safety equipment was inoperable simultaneously for reasons other than loss of power, single train LCO clocks would start under other technical specifications, and immediate shutdown would not be required.
Whether this was the reasoning or not, and whether the staff or industry proposed it, a crucial change was made to the wording of the CONDITION that makes it clear that the threshold and litmus test for degradation of electrical distribution systems requiring 3.0.3 entry was loss of safety function. Thus, the proposed CONDITION was approved for incorporation in. Revision 1 of STS as follows:
BWR/4 "Two or more electrical power distribution subsystems inoperable that result in a loss of function."
BWOG "Two or more inoperable distribution subsystems that result in a loss of function."
WOG "Two trains with inoperable distribution subsystems that result in a loss of safety function."
CEOG "Two or more inoperable distribution subsystems that result in a loss of function."
Thorough analysis at the time when NRC-02 was evolving would have lead to the realization that it was logically incomplete. If we postul'ate a set of plant states characterized as "two or more subsystems inoperable", then we have subsets that lead to loss of function and subsets that do not lead to loss of function. Then in order to avoid default into 3.0.3 we must specify conditions and actions for both subsets. NRC-02 was incomplete in that it did not provide this specificity for the "no loss of function" subset, thus defeating the intent of the addition of the "61m~s of function" modifier to narrow the circumstances requiring shutdown, i.e., for two or more subsystems inoperable with loss of function the plant enters 3.0.3 explicitly; for two or more subsystems inoperable without loss of function the plant enters 3.0.3 implicitly. So as it stands the loss of function determination is irrelevant because plant shutdown is required no matter what the outcome.
Under the circumstances described above, all plant designs have a problem except, as'noted earlier, BWR/4s. Interestingly, TSTF 16 was originated sometime in mid-1 994 by the BWROG to fix the problem for BWR/6s, and later adapted through the TSTF review process for application to PWR designs. As described above in the Description of Proposed Changes, TSTF 16 Rev I replaces 'one" with "one or more" in CONDITIONS A, B, and C, leaving implicit in the CONDITIONS but making explicit in the Bases that these conditions apply to "one or more" subsystem(s) or bus(es) inoperable without loss of function.
The combination of NRC-02 and TSTF 16 Rev I comprises a logical whole that meets the technical specification structuralllogic rules, It can be improved by making the "no loss of function" premise for CONDITIONS A, B, and C explicit, and by some additional modifications of the Bases as discussed under Bases Improvements. However, concerns expressed about its efficacy, i.e., quality and timeliness of the process for determining loss of function, are not peculiar to 3.8.9 but relate to how technical specifications work in general and are discussed below. It Is reasonable to conclude that the quality and timeliness of determining loss of function will be adequate in the context of 3.8.9 as revised by TSTF 16 Rev 1.
Knowledge of Support-Supported System Relationships It is reasonable to rely on licensee knowledge of support-supported system relationships for 3.8.9.
Knowledge of the relationships between and among support and supported systems is essential and fundamental to determinations of operability throughout technical specifications. This results from the definition of OPERABILITY as found in technical specifications:
"A system, subsystem, train, component, or device shall be OPERABLE or have OPERABILITY when it is capable of performing its specified safety function(s) and when all necessary attendant instrumentation, controls, normal or emergency electrical power, cooling and seal water, lubrication, and other auxiliary equipment that are required for the system, subsystem, train, component or device to perform Its specified safety function(s) are also capable of performing their related support function(s)." (Emphasis added)
Current inspection guidance on this point in IMC Chapter 9900 (10/31/91) states:
"OThe definition of operability embodies a principle that a system can perform its specified safety function(s) only when all its necessary support systems are capable of performing their related support functions. Therefore, an NRC inspector should expect that each licensee understands which support systems are necessary to ensure the operability of main systems and components that perform specified safety functions. Such an
ý,iiderstanding is mandatory. Otherwise the licensee will not be able to implement the definition of operability." (Emphasis added.)
Thus, knowledge of support-supported system relationships is a fundamental prerequisite for operation within tech specs of whatever vintage. This knowledge is scrutinized during day-to day operations by resident inspectors and others in reviewing technical specification compliance and operability determinations. Regulatory developments such as IPEs, CRMPs, and the risk configuration management required by the revised maintenance rule have provided additional focus on this area.
No Time Limit for Determining Loss of Function It is reasonable to expect that loss of function in the context of 3.8.9 will be determined promptly.
Determining loss of function is dependent on the process for making operability determinations, so that process will be discussed first. This process itself inherently drives toward loss of function determination. Nonetheless, the need to determine of loss of function is additionally and explicitly covered by the Safety Function Determination Program (SFDP) invoked by 3.0.6 and defined in Section 5.5 of STS.
Technical specifications themselves do not contain rules or time limits for operability calls, and this pertains to all specifications, not just 3.8.9. However, the agency has long held and enforced a principle of promptness as described in IMC 9900:
"Once a degraded or nonconforming condition of specific SSCs is identified [by "an ongoing and continuous process" of ensuring operability], an operability determination should be made as soon as possible consistent with the safety importance of the SSCs affected. in most cases, it is expected that the decision can be made immediately (e.g., loss of motive power, etc.) In other cases it is expected the decision can be made within approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of discovery even though complete information may not be available. Some few exceptional cases may take longer. For SSCs in TS, the Allowed Outage Times (AOTs) contained in TS generally provide reasonable guidelines for safety significance." (Emphasis added.)
With reference to the bolded text above, the "AOT" or Completion Time for the 3.8.9 CONDITION specifying loss of function is "Immediately", implying the highest safety significance and hence the promptest operarability determination.
Because determination of operability is a continuous evaluation process, and because the definition of operability includes availability of support systems, a degraded or nonconforming condition in a subsystem covered by 3.8.9 will result in an operability review for supported
systems. Thus the operability determination process itself drives towards detecting loss of function. Degraded and nonconforming conditions in supported systems that do not originate with support systems are also continuously evaluated for operability impact, and the combined results determine the LCOs not met and actions entered.
Thus in practice, a safety function determination program-small sfdp-is in operation before, and in order to establish conditions for, entry into 3.0.6 where the formal Safety Function Nu.t-rmination Program-capital SFDP-resides. Entry into 3.0.6 requires that a supported system LCO is not met solely due to a support system LCO not being met. [As an aside, while 3.0.6 appears necessary to determine which LCOs take precedence to prevent cascading, the SFDP should be invoked outside of 3.0.6, possibly in 3.0.2, since safety function determination is needed (and actually done) as part of operability determination.] Entry into 3.0.6 just makes doubly sure that loss of safety function is specifically examined when all the problems originate with support systems. But practically speaking, the loss of function will be known beforý invocation of this SFDP, and the more serious the 3.8.9 degradation, the easier and faster the determination.
Improving the Bases With the revisions proposed in TSTF 16 Rev 1, CONDTIONS A and C pertain to the inoperability of "One or more [AC or DC, respectively] electrical power distribution subsystem(s)..." Turning to the Bases, the initial words for these conditions in general are variants on "With one or more required AC (or DC) buses, load centers, motor control centers, or distribution panels inoperable.." The reader is expecting the words to be "With one or more subsystem(s) inoperable", consistent with the wording of the condition. The precise relationship between "buses, load centers, motor control centers, or distribution panels" and "subsystem" is nowhere provided, leaving the reader to wonder if each one of these components is a "subsystem".
Clarity of 3.8.9 would be greatly improved if somewhere the hierarchy of train/division/subsystem/bus/motor control center etc. was explained. It appears that the following relationship is assumed:
A train or division consists of one or more distribution subsystems, which in turn are made up of one or more buses, load centers, motor control centers, or distribution panels. A subsystem supports one set of redundant safety equipment needed to perform a safety function.
Jack Donohew - Draft 3.8 Bases Words Pane From:
"Don Woodlan" <dwoodlal @tuelectric.com>
To:
OWFN. -DO.owf4_po(JND,NVG)
Date:
Tue, Jan 12,1999 12:14 PM
Subject:
Draft 3.8 Bases Words From: Don Woodlan@TU on 01/12/99 11:14 AM To: jnd@nrc.gov, NVG@nrc.gov cc: Bob Dacko/CPSES/Texas Utilities @ TU, pxn2 @ pge.com, deshafer@ cal.ameren.com, stwidem@wcnoc.com, ggyates @ cal.ameren.com, jes2 @ pge.com, samaglio@cal.ameren.com, Dennis Buschbaum/CPSESiTexas Utilities@TU, LeParme@wcnoc.com, James Boatwright/Texas Utilities@TU, mhfletcher0cal.ameren.com, Charles Feist/CPSES/Texas Utilities@TU, imchapman@cal.ameren.com, gps3@pge.com, Matt Bozeman/CPSES/Texas Utilities @TU, Roger Walker/CPSES/Texas Utilities @TU, William Guldemond/CPSES/Texas Utilities @TU, Gregory Muchow/CPSES/Texas Utilities@TU
Subject:
Draft 3.8 Bases Words Here are some draft words to consider in our upcoming phone call.
Bases insert for ITS Bases Sections 3.8.2 and 3.8.10 at the end of the Applicable Safety Analyses subsections:
In addition to the requirements tablished by the lechnical specifications, the plant staf anager shutdown tasks and electrical pporimaintain*
risk at an acceptably low value.
As required by the technical specifications, one train of the required equipment during shutdown conditions is supported by one train of AC and DC power and distribution. The availability of additional equipment, both redundant equipment as required by the technical specifications and equipment not required by the specifications, contributes to risk reduction and this equipment should be supported by reliable electrical power systems. Typically the Class 1 E power sources and distribution systems of the unit are used to power this equipment because these power and distribution systems are available and reliable. When portions of the Class I E power or distribution systems are not available (usually as a result of maintenance or modifications), other reliable power sources or distribution are used to provide the needed electrical support. The plant staff assesses these alternate power sources and distribution systems to assure that the desired level of minimal risk is maintained (frequently referred to as maintaining a desired defense in depth). The level of detail involved in the assessment wil; vary with the significance of the equipment being suppo,1-,c.
In sorm, cases, prc,-ared guidelines are used which include controls designed to manage risk and retain the desired defense in depth.
- Thanks, Don (D. R. ) Woodlan
EXAMPLE OF INSERT FOR ITS 3.8 ELECTRICAL POWER SHUTDOWN BASES AGREED TO BY EELB. SR>(B. AND TSB
- 1. General Statement Applicable to Entire Body of the Shutdown Technical Specifications The shutdown technical specifications by themselves do not ensure an acceptably low level of risk is maintained for all shutdown operations. During some shutdown conditions the minimum requirements of the shutdown technical specifications must be supplemented with additional voluntary measures to ensure an acceptable level of risk is maintained. This is accomplished by.....
- 2. Statement Applicable to a Specific Section of the Shutdown Technical Specifications (AC, DC, and Vital AC)
Electrical system power during shutdown is generally provided by the normal redundant Class IE power systems to the redundant systems/equipment required to be operable.
However, due to required maintenance of the Class 1 E equipment, ron-Class I E power may be substituted for one of the Class IE power sources. This results in one division of full Class 1E power (AC. DC, and vital AC) with the required DG backup, and a second division with a mix of Class IE and non-Class 1E power. PFior to making this switch to non-Class IE power, an assessment will be performed to ensure a commensurate level of safety is maintained to the required operable safety systems to be powered by the non-Class IE power source.
Consistent with the preceding discussion on the Comanche Peak approach we believe the Reviewer's Note provided in revision 1 to TSTF-204 should be changed to read:
Reviewer's Note: This second option above applies for plants having a CTS for electrical power requirements during shutdown conditions that require only [one]
DC electrical power subsystem/ inverter to be OPERABLE. The "[or more]"
opional wording in Condition A is also eliminated for this case. The first option above is adopted for plants that have a CTS requiring the same level of DC electrical power subsystem /inverter support to equipment required to be operable as is required for power operating conditions.
Example #
3 note Not required to be performed until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after Ž 25% RTP.
4 Only required to be met in Mode 1.
5 Only required to be performed in Mode 1.
6 Not required to be met in Mode 3.
ATTACHMENT 3