ML20205P033
| ML20205P033 | |
| Person / Time | |
|---|---|
| Issue date: | 04/14/1999 |
| From: | Matthews D NRC (Affiliation Not Assigned) |
| To: | Pietrangelo A NUCLEAR ENERGY INSTITUTE (FORMERLY NUCLEAR MGMT & |
| References | |
| PROJECT-689 NUDOCS 9904200003 | |
| Download: ML20205P033 (12) | |
Text
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April 14, 1999 Mr. Anthony Pi::trangelo, Director a
Licensing 4
' Nuclear Energy Institute i
Suite 400 1776 l Street, NW j
. Washington, DC 20006-3708
SUBJECT:
REVIEW OF INDUSTRY DRAFT GUIDANCE ON DESIGN BASIS INFORMATION AS DEFINED IN 10 CFR 50.2
Dear Mr. Pietrangelo:
This letter forwards NRC staff comments on the industry draft guidance on design basis information (as defined in 10 CFR 50.2) that NEl provided to the staff during a meeting on February 18,1999. The staff comments are included as Enclosure 1. As a follow up to this meeting, and for the sake of completeness, Enclosure 1 also includes staff comments on the draft revised Appendix B to NEl 97-04," Design Bases Program Guidelines," that was forwarded to the staff on January 27,1999.
I am also providing, herewith as Enclosure 2, a copy of our milestone schedule for completion of the Define Design Basis Task from the April 12,1999, memorandum " Update to Staff Response to Tasking Memorandum and Stakeholder Concerns." In order to meet the schedule in the milestone chart, I am asking you to commit to meet the June 1,1999, milestone for submitting a revised NEl guidance document. As stated in the comments on the milestone chart, the staff is prepared to develop a proposed regulatory guide on this topic in the event that NEl decides not to pursue further development of guidance on the definition of design basis information. However, our past experience on the development of guidance on updating Final Safety Analysis Reports (NEl 98-03, DG-1083) indicates that the process works better for all parties if prior consensus on, and endorsement of, an industry guidance document can be reached.
I look forward to continuing our discussion of design bases issues and I hope that the attached comments r.nd milestone chart will facilitate the discussion at the meeting scheduled for April 16,19 39. Please feel free to call me or Stewart Magruder of my staff with any questions.
Sincerely, Original Signed By:
1 ahws, Medor 9904200003 990414 PDR REVQP ERONUNRC Division of Regulatory improvement Programs
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PDR Office of Nuclear Reactor Regulation Project No. 689 K.,6)$
Enclosures:
As stated y
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i April 14; 1999 Mr. Anthony Pietrangelo, Director Licensing Nuclear Energy Institute Suite 400 1776 i Street, NW Washington, DC 20006-3708
SUBJECT:
REVIEW OF INDUSTRY DRAFT GUIDANCE ON DESIGN BASIS INFORMATION AS DEFINED IN 10 CFR 50.2
Dear Mr. Pietrangelo:
This letter forwards NRC staff comments on the industry daft guidance on design basis information (as defined in 10 CFR 50.2) that NEl provided to the staff during a meeting on February 18,1999. The staff comments are included as Enclosure 1. As a follow up to this meeting, and for the sake of completeness, Enclosure 1 also includes staff comments on the draft revised Appendix B to NEl 97-04, " Design Bases Program Guidelines," that was forwarded to the staff on January 27,1999.
I am also providing, herewith as Enclosure 2, a copy of our milestone schedule for completion of the Define Design Basis Task from the April 12,1999, memorandum " Update to Staff Responso to Tasking Memorandum and Stakeholder Concerns." In order to meet the schedule in the milestone chart, I am asking you to commit to meet the June 1,1999, milestone for submitting a revised NEl guidance document. As stated in the comments on the milestone chart, the staff is prepared to develop a proposed regulatory guide on this topic in the event that NEl decides not to pursue further development of guidance on the definition of design basis information. However, our past experience on the development of guidance on updating Final Safety Analysis Reports (NEl 98-03, DG 1083) indicates that the process works better for all parties _if prior consensus on, and endorsement of, an industry guidance dccument can be reached.
I look forward to continuing our discussion of design bases issues and I hope that the attached comments and milestone chart will facilitate the discussion at the meeting scheduled for April 16,1999. Please feel free to call me or Stewart Magruder of my staff with any questions.
Sincerely.
i David B.' Matthews, Director Division of Regulatory improvement Programs -
Office of Nuclear Reactor Regulation i
Project No. 689
Enclosures:
. As stated cc w/ encl: See next page 4
STAFF COMMENTS ON INDUSTRY DRAFT GUIDANCE ON DESIGN BASIS INFORMATION AS DEFINED IN 10 CFR 50.2 The comments in this enclosure are provided for information and to facilitate discussion. A specific answer to each comment is not expected or required.
General Comments 1.
The draft guidance on 10 CFR 50.2 design bases provided by NEl on February 18,1999, is a good start to clearly describe what constitutes design basis information. However, the guidance should be expanded so that the appropriate scope and the right level of detailis captured in Appendix B of NEl 97 04, it is not clear from the NEl draf t guidance which design bases information needs to be directly addressed by examples in NEl Appendix B and the section on topical design bases.
2.
In reviewing the examples provided in draf t revised Appendix B, forwarded by NEl's letter of January 27,1999, we identified a general concern related to the distinctions drawn between design basis and supporting design information. It would seern that the boundary between these two categories should be placed generally as follows: design basis information including the associated limits and performance parameters, should include those items that,if not met, would render the SSC incapable of performing its intended function (s). This appears consistent with the type of information listed in Section (e) under " specific guidance" of the enclosure to the January 4,1999 NRC letter to NEl. Supporting design information, on the other hand, should encompass design features that,if not met, could result in degradation or margin-related problems only. We noted that NEl, in their examples, placed some items in the supporting design information category that could reasonably be expected to impact functionality, such as required net positive suction head, hot leg recirculation capability, electrical power supply redundancy, and injection valve stroke times.
j 3.
During an earlier review of NEl 97#4, differences were noted between the staff and NEl on the definition of " Design Bases. These differences were discussed in the original NRC response to NEl regarding interpretation of " Design Bases", dated August 18, 1998. The NRC response indicated that the NEl interpretation was not consistent with 4
regulatory guidance as specified in NUREG 1397 and ANSI N45.2.11-1974. These l
documents specify that design bases include design inputs such as applicable codes and standards, design conditions such as pressure, temperature, fluid chemistry and vnItage and performance requirements such as capacity, rating and system output.
Based on our review, the January 27,1999, NEl revision to Appendix B docs not appear to resolve this conflict in interpretation of design bases. Although the revised NEl Appendix B provides increased detail, it continues to describe design input information such as pen'ormance requirements, applicable codes and standards, and design conditions as " supporting design information" and not design bases.
The crux d our concem with NEi's attempt to distinguish between design bases and supporting design information is the implication that the latter can be changed (i.e., a reduced, moditied. and/or degraded condition could exist) without the regulatory constiaints applied to the evaluation of such changes. Our overall position is still closely aligned with the Aug 18,1998, response to NEl.
4.
Consi5 tent vnt" comment n,s. :-3, we recommend that more guidance be added regarding the scope of information falling within the categories of "e Mgn bases" and
" supporting information." This guidance could be similar to that !
,ed in Section (e) of the draft specific guidance provided by the staff in our January 4,1999, letter.
5.
The quality ard consistency (level of detail, topical issues, BWR vs. PWR, system vs.
system, etc.) of the examples provided in NEf s Appendix B should be irnproved.
Comments on Draft General Guidance item 1 6.
The definition provided by Draf t General Guidance item 1 appears to exclude some of the information used to demonstrate the General Design Critena in Part 50 Appendix A are met. Appendix A states that "The principal design criteria establish the necessary design, f abt. cation, construction, testing, and performance requirements for structures, systems, and components important to safety." As a result, the design basis functions must include, design, fabrication, construction, testing, and performance requirements.
A few functions that would not (or might not) be considered design basis information using the NEl guidance are: inherent nuclear feedback (GDO-11); systems designed to be inspectable and testable (GDC-18,21,32,36,37,39,40,42,43,45,46,52,53);
protection systems aesigned to initiate automatically (GDC 20); perhaps even all the applicable quality standards (GDC 1, 14,21, 30). Any design function that goes beyond what is required to mitigata postulated events, like, diverse reactivity control and perhaps some of the containment isolation requirements appear to be excluded from the NEl guidance.
7.
NEl desenbes applicable functions as those " required by NRC regulations or order,"
excludir.g license condition. When comparing the NEl 2/18/99 guidance and the NRC 1/4/99 cnteria, we consider:
- The *.m license condition should not be eliminated.
To be consistent with 10 CFR 50.5(a)(1), the terms to be used would be those functions ' required by NRC rule, regulation, or order or any term, condition or ! imitation of the license',
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8.
The wording of wording of Draft General Guidance item 1 needs revision to specify that the de:uon basis functions are those required for withstanding postulated events (in addition to responding to postulated events), For example, the design bases include requirements hat SSCs withstand seismic events.
Comment on Draft Specific Guidance a) 9.
The guidance should clearly state that the design basis functions should also be based on the station blackout and ATWS events.
Comment on Draft Specific Guidance b) 10.
Conceming the NEl draft specific guidance, item (b), we considered this view to be inconsistent with 10 CFR 50.2 because it unacceptably limits "the specific values or ranges of values chosen for controlling parameters as reference bounds for the design" as stated in 10 CFR 50.2. We believe that with respect to the definition of design basis as it applies to design control, it was the intent of the regulation that the " controlling parameters," in large part, were specified at the train or major component level and not exclusively at the system W el. We believe " reference bounds for the design" was intended to include all of the analytic limits needed to ensure that the equipment (e.g., a pump or a turbine dnven auxiliary feedwater pump steam admission valve) would accomplish the safety functions with suitable redundancy and diversity. The NEl guidance does not appear to be an appropriata characterization of design control requirements.
11.
NEl's draft specific gu m,ce indicates th:.t "Although every structure and component has a design basis, structure and component design basis functions are generally implicitly bounded by the 10 CFR 50.2 design basis for the system. Structure and component functions are considered 10 CFR 5].2 design basis only if both the following criteria are met.." The staff believes that system-level design information is generally not sufficient to define the design basis of structures and components.
Comments on Examples From Accendix B of NEl 97-04 12.
With the understanding that design-basis information should include SSC c~iaracts.istics that were key to a plant license, many of the examples provided as " supporting design information" appear to be design basis information. For example:
- RHR/LHSi pump flows must not exceed XXXX gpm during cold leq recirculation to ensuia adequate NPSH is available for the RHR/LHSI pumps l
- The RHR heat exchangers shell side is designed and fabricated to the requirements f
defined in ASVE Se, tion Vill. The tube sido is designed to ASME Section Ill, Class C.
- The design pressure of the containment is XX psig and - XX psig. The design i
Vmperature is XXX ~ F.
I
13.
Similar to item 12 above, it appears that some design-basis information was mistakenly described as an example of "suppotting design information". In NEl's reactor vessel example, the reactor vessel supporting design information includes "The reactor vessel is designed and f abricated in accordance with the requirements of ASME Section lil, Class l' This statement should be revised to read "The reactor vesselis designed and fabricated in accordance with the requirements of 10 CFR 50.55a(c)" and this statement should be included as design basis information.
14.
Similar to comments 12 and 13 above, where a licensee has committed to a particular regulatory guide (or had some other method for complying with a particular regulation I
specifically approved by the NAC), that commitment should be included as design-bases information. For example:
The system is designed to meet 'he regulatory position given in Regulaton/ Guide 1.1, November 1970.
The generators snall meet the requirements of Regulatory Guide 1.6 -Independence Between Redundant Standby (Onsite) Power Sources and Between Their Distribution Systems; Regulatory Guide 1.9 -- Selection of Diesel Generator Set Capacity for Standby Power Supplies; and NEMA MG1.
15.
The wordirg of BWR Residual Heat Removal System design bases first bullet should be revised to also specify what pressure the minimum flow is required at.
16.
The example for BWR LPCS system design bases included a listing of parameters used to bound LPCS capability. A similar type of listing should be included for most of the system examples.
17.
Many of the " Supporting Design ink ation" examples include information which should be part of the " Design Bases." E, cally, many of.he examples do not meet paragraph (e) of the [NRC Draft]..ecific Guidance. Some examples are:
PWR RHR Supporting Design Informatior. 3rd Bullet: Basis for heat exchanger sizing would normally be considered part of the design bases.
PWR RHR Supporting Design Information 4th Bullet: Testing capability is a regulatory requirement and should be part of the design bases.
PWR RHR Supporting Design Information,8th Bullet: The requirement to withstand XXX cycles would normally be part of the design bases.
PWR RHR Supporting Design Information,4th Bullet: The requirement to meet ASME Code is a regulatory requirement and should be part of the design bases.
-mm
BWR RHRS Supporting Design Information,7th Bullet: Whether positive containment pressure is relied upon to ensure adequate net positive suction heaa should be part of the design bases.
BWR RHRS Supporting Design Information,8th Bullet: The requirement to mect ASME Code is a regulatory requirement and should be part of the design bases.
BWR RHRS Supporang Design Information,9th Bullet: The functional requirement to protect against effects of pipe whip should be part of the design bases.
BWR RHRS Supporting Design Information,10th Bullet: Although actual r it point values may not be part of *.ne design bases, the functional requirements and underlying assumptions for which the set points were established should be part of the design bases. Similar logic applies to the 12th and 13th bullets for BWR RHRS Suoporting Design information.
BWR Containment Supporting Design information,2nd Bullet: The functional requirement to withstand jet impingement forces should be part of the design bases.
PWR AFW System Supporting Design information,2nd Builet: The ability to operate in an ambient air temperature environment of : XXX'F describes an interfacing requirement for room coolers and should be part of the design bases.
PWR AFW System Supporting Design Information,4th and 5th Bullets: The requirement to meet ASME Code is a regulatory requirement and should be part cf the design bases.
BWR LPCS Supporting Design Information,5th Bullet: The need to maintain the
'.PCS and RHR systems in solid water conditions is a design basis requirement BWR LPCS Supporting Design hformation,7th Bullet: LPCS system NPSH requirements is design basis information.
BWR LPCS Gupporting Design Information,10th and 11th Bullet: The requirement for LPCS to be able to function for XXX hours is a design bas:s requirement.
BWR RPS Supporting Design Information,2nd Bullet: Physical separation requirements are design basis information.
BWR RPS Supporting Design infermation,3rd Bullet: The requirement to be able to function independently is a design basis requirement.
BWR RPG Supporting Design Information,4th Bullet: Single f ailure criteria and the effect of testing are oesign basis recuirements.
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- -- J
BWR Main Steamline Flow Restrictors Supporting Design information,2nd
=
Bullet: The specified throat area is a design bas 1 requirement because it defines the effect on the NSSS.
Reactor Vessel Supporting Design Information. 2nd Bullet: RPV design pressures and temperat';res are design bases.
Reactor Vessel Sur Sorting Design Information,5th Bulfet: RPV peak end-of-life fluence should be part of the design bases.
5 18.
The NEl Draft Guidance does not address Topical Design Bases and this is reflected in the NEl Appendix B wnte-ups.
For example, in NEl Appendix B, page 9, third bullet, the BWR Containment Supporting Design Information sectior' lists a small portion of 10 CFR 50, Appendix B, Criterion 55,56 & 57 regarding contair ment isolation simple check valve design criteria.
These en:eria are applicable to other s) stems in Appendix B but are not addressed in the other system's de :
- hases. Per the definition of a 's opical Design Basis in Appendix B (". design oases topics that arc common to numerous systems, structures, or components.
") 10 CFR 50, Appendix B, Criterion 54 through 57, which dea! with containment penetration isolation, should be part of the Topical Design Bases section and referenced in the system design bases document for all applicable systems. The Topical Design Bases section does mention containment isolation valves regarding location to meet a " Containment design criteria document."
- The NEl Draf t Guidance does not provide guidance on what would qualify as a Topical Design Basis, what shoulo De contained in a Topical Design Basis or what should be contained in a Containment Design Criteria Document (or a Natural Phenomena Design Bases Document, which is also referenced in the NEl Topical Design Bases section).
19.
The statement, " Hydrogen generation shall be limited to less than one percent of the amount that would be generated by the complete oxidation of all metalin the cladding,"
which appears under the headirigs " Examples of Plant Level 10 CFR 50.2 Design" and "PWR Residual Heat Removal System (RHRS) 10 CFR 50.2 Design Bases,"is incorrect. As stated in 10 CFR 50.46(b)(3), the cladding surrounding the plenum volume is excluded in the calculation of this criterion.
4 9
IV. Toolc Area: Reactor Licensina and Oversicht -
SES Manager: David Matthews, Director, DRIP /NRR D. Specific lasue: Define Desian Basis Objective: To provide a clear definition of what constitutes design bases information.
PRIOR TO JANUARY 28,1999 Milestone Date Lead
- 1. NEl submits 97-04 for information 10/8/97C S. Magruuer, DRPM
- 2. SRM/SECY-97-205 directs staff to continue to 3/2 % so S. Magruder, develop guidance regarding design bases issues DRPM
- 3. Issue preliminary staff comments on NEl 97-04 8/18/98C S. Magruder.
DRPM
- 4. Meet with NEl to discuss staff comments on 9/18/9.8C S. Magruder, NEl 97-04 DRPM PRIOR TO JUNE 30,1999 Milestone Date Lead
- 5. Meet with NEl Task Force to discuss draft criteria 4/1669 S. Magruder, and additional examples DRIP
- 6. Send letter to NEl with staff position 5/7/99 S. Magruder, DRIP
- 7. 5-NEl submits revised guidance for review and S/99 S. Magruder, endorsement 6/1/99 DRIP
- 8. 6-Resolve final staff comments and develop draft 5/99 S. Magruder, regulatory guide 6/15/99 DRIP PRIOR TO SEPTEMBER 23,1999 Milestone Date Lead 9.E ACRS and CRGR review of SECY and draft 6/99 S. Magruder, regult ary guide thet endorses NE! 97-04 7/99 DRIP
- 10. 6-Submit paper with draft regulatory guide to 6/99 S. Magruder, Comraission (9800044) (NRR) 7/30/99 DRIP
e p.
Nuclear Energy Institute Project No. 689 cc:
Mr. Ralph Beedle Ms. Lynnette Hendncks, Director Senior Vice President Plant Support and Chief Nuclear Officer Nuclear Energy Inst:tute Nuclear Energy Institute
. Sude 400 Suite 400 1776 i Street. NW 1776 l Street. NW-Washington, DC 20006-3708 Washington. DC 20006-3708 Mr Ale- :d anon. Director Mr Charles B Brinkman. Director Programs Washington Operations Nuclear Energy institute ABB-Combustion Engineering, Inc.
Suite 400 12300 Twinbrook Parkway, Suite 330 1776 i Street. NW Rockville. Maryland 20852 Washington. DC 20006-3708 Mr David Modeen Director Engineenng Nuclear Energy institute Suite 400 1776 i Street. NW Washington. DC 20006-3708 Mr Anthony Pietrangelo. Director Licensing Nuclear Energy Institute Suite 400 1776 l Street, NW Washington. DC 20006-3708 Mr Nicholas J. Liparulo, Manager Nuclea: Safety and Regulatory Activ' as Nuclear and Advanced Technology Division Westinghouse Electric Corporation P O. Box 355 Pittsourgh, Pennsylvania 15230 Mr Jim Davis Director Operations Nuclear Energy Institute Suite 400 1776 l Street. NW Washington. DC 20006 + 'B l
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