ML20245A483
| ML20245A483 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 04/04/1989 |
| From: | Kintner E GENERAL PUBLIC UTILITIES CORP. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8904250228 | |
| Download: ML20245A483 (6) | |
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_. c GPU Nuclear Corporation
.,, f S yn One Upper Pond Road 7"
emu Parsippany, New Jersey 07054 201-316-7000 April 4, 1989 TELEX 136-482 Wnter's Dirt.1 Dial Number:
Mr. Dennis M. Cruthfield Acting Associate Director for Projects Office of Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, D.C.
20655
Subject:
Potential Review Issues for the ALWR
Dear Mr. Crutchfield:
The attachment to your letter to me on the above subject dated November 22, 1988, describes the scope of the NRC staff's review of safety analysis reports for future standard design applications, as well as staff views on certain potential review subjects.
Attached is a summary of the approach we are taking in the ALWR Program to address the potential design issues described in your letter along with our suggested course of action to reach resolution on those issues for the ALWR.
If you have any questions, please get in touch with Mr. Jack DeVine at EPRI (415) 855-2068.
Very truly yours, m
E w n E. Kintner, Chairman ALWR Utility Steering Committee STG:RMD/5089MS9 Encl: a/s cc:
Karl Stahlkopf, EPRI J. DeVine EPRI ALWR Staff ALWR Contractors Utility Steering Committee l
Bill Rasin, NUMARC i
8904250228 B90404
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DR ADOCK 050 9
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GPU Nuclear Corporation is a subsidiary of General Pubhc Utsties Corporation i
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Attachment 1.
Scope of Design Discussion:
NRC indicates that in the proposed regulation, 10 CFR Part 52, it is stated that ideally, designs for which certification is sought would be for essentially complete plants.
This is consistent with the policy and approach being followed in the ALWR Program.
We believe that interaction among different segments of the design play an important part in a plant's overall performance and safety, and therefore the plant should be designated an integrated, adhesive whole.
For that
- reason, the ALWR Requirements Document covers the entire
- plont, to the grid interface.
Regarding design completeness, the Requirements Document calls for 90%
of engineering to be complete at beginning of construction.
We do not-specify the degree of completeness necessary for certification, but we suspect that many of the engineering design details necessary to support an efficient high quality construction job would have no bearing on the plant certification process.
2.
Design Life of 60 Years Discussion:
For applications proposing a 60 year design life, the NRC staff would review the designs for a 60-year life notwithstanding the fact that a 40-year license tern limitation is presently in the regulations.
Response
The ALWR Requirements Document specifies that an ALWR shall be designed to operate for 60 years without the need for a refurbishment outage and to permit expeditious component replacement for obsolescence and failure over the 60-year lifetime.
The NRC review of 60-year plant designs is necessary for achieving the full benefit of the ALWR requirements.
l 3.
Fire Protection l
Discussion:
The NRC staff indicates that improved fire protection criteria are needed and that the current Appendix R
and BTP 9.5-1 requirements, e.g.,
for 20 foot separation, should be replaced by I
a requirement for safe shutdown capability in the 5089MS9R l
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l staff and to obtain a better understanding of the intent of the NRC proposed improved fire protection criteria.
We intend to work close'.y with the NRC
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to assure satisfactory resolution of this item.
4.
Technical Specifications Discussion:
The NRC staff considers that (1) proposed Technical Specifications representative of the design should be submitted no later than the FDA application and will be reviewed and approved by the staff as part of the FDA review and (2) applicants should identify design features that are necessary for testing and maintenance during operation without challenging safety systems.
EPRI Response:
We concur that early submittal and review of plant technical specifications is desirable and should enhance regulatory stability.
However the specific timing for technical specification submittal is a licensing matter involving NRC and the applicantTis not to be a subject within the scope of the considereJ Requirements Document.
5.
Testing and Maintenance Discussion:
The NRC staff states that certification of a design will be based in part upon a
probabilistic risk assessment of the design.
Given that the validity of the PRA is highly dependent on the reliability of systems, structures, and components, assurance is needed that programs will be implemented which will ensure that the reliability of these systems, structures, and components will be maintained throughout plant life.
Therefore, programs to assure design reliability must be provided as part of the FDA application and should address items such as (1)
Technical Specifications (2) In-service Iaspection and Testing, (3)
Maintenance Program, (4) Plant Procedures and (5) Security.
EPRI Response:
We concur with the cencept that programs to assure plant lifeti e reliability for critical
- systems, structures and components is appropriate.
- However, the specific timing and items to be addressed in the reliability program are licensing matters involving the NRC and the applicant and are not considered to be within the scope of the ALWR Requirements Document.
5089MS9R 3
6.
Industry Use of MAAP Discussion:
The NRC staff considers that review by the NRC of the MAAP ccde is unnecessary since the staff can apply its own MELCOR and Source Term Code Package (STCP) codes in its evaluations.
EPRI Response:
We believe that the MAAP code is the best code currently available and have specified its use for containment analysis and source term calculations for the ALWR.
We believe that MAAP is more suitable than STCP for production use for industry evaluation of severe accident sequences.
As far as we are aware, MELCOR is still in an early stage of development and will not be mature enough for use in the timeframe it would be required.
We suggest that further EPRI/NRC discussions be conducted on this subject, and as a first step, we propose to present to the NRC staff the programmatic and technical approaches taken in the MAAP code.
7.
Station Blackout and Electrical System Discussion:
The NRC staff considers that ALWRs should adopt improved electrical systems to ensure a safe shutdown of the reactor.
These systems should provide the diverse power sources in order to eliminate concerns related to station blackout.
EPRI Response:
Chapter 11 of the ALWR Requirements Document specifies requirements which directly address the elimination of station blackout concerns.
Improvements are specified in offsite power reliability, vnsite powre reliability and capacity, and station blackout coping capability.
Specifically, Chapter 11 will call for a large capacity, diverse on-site AC source that will meet all the design-related criteria for an alternate AC source specified in Appendix B of Regulatory Guide 1.155.
Chapter 11 currently specifies a
gas turbine as the preferred choice for this non-safety on-site source.
8.
Leak-Before-Break Discussion:
The NRC notes that a new rule and draft SRP Section 3.6.3 have been issued to address justification for leak-before-break evaluations.
Response
The ALWR Requirements Document specifies requirements which are consistent with the NRC criteria.
The application of leak-before-l 5089MS9R 4
break was an optimization subject identified for Chapter 1 of the _ Requirements Document and was resolved during the NRC review of Chapter 1.
9.
Source Terms Discussion:'
The NRC staff is concerned that the licensing basis source term " TID 14844" is not consistent with current knowledge and expects that, with EPRI input, realistic source terms will be established to. be uniformly applied to -future ALWRs.
EPRI Response:
We agree that a considerable body of information on source terms is now available and should be utilized in definition of more realistic source terms and dose calculation assumptions and methods.
The ALWR Program is eager to cooperate
.with the NRC in this effort.
We are currently preparing a
draft approach which outlines reasonable changes to - the existing Regulatory Guides 1.3 and 1.4 dose calculation process and plan to submit it to you, in the near future, for your consideration.
10.
Physical Security Discussion:
The NRC staff' considers that sabotage should be addressed in all ALWR applications.
As a minimum, the NRC expects that information should be provided to demonstrate.the existence of adequate physical barriers to protect vital equipment in accordance with 10CFR73.55(c) and to identify access control points to all. vital areas in accordance with 10CFR73.55(d).
EPRI Response:
Chapter 5 of the ALWR Requirements document specific requirements for physical separation for engineered safety systems.
Chapter 6
addresses access control and separation requirements, while Chapter 9
covers security systems and required provisions.
It is expected that the aggregate set of requirements described in Chapters 5, 6 and 9 will provide a sufficient level of sabotage protection for the ALWR.
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11.
OBE/ Dynamic Analysis Methods Discussion:
The NRC staff states that the OBE should not control the design of safety systems as now required by 10CFR100 Appendix A.
5089MS9R 5
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I EPRI Response:
This issue has been identified as an optimization subject for Chapter 1 of the ALWR 1
Requirements Document.
EPRI will continue to work with the NRC to come to satisfactory resolution of this issue.
12.
Type C Containment Leakage Rate Discussion:
Containment leakage is acknowledged by the staff as being a
function of containment pressure rather than independent of pressure.
EPRI Response:
This position is consistent with the requirements in Chapter 5
of the ALWR Requirements Document.
13.
Hydrogen Generation Discussion:
The NRC staff intends to invoke 10CFR50.34(f) related to the issue of 100% metal-water reaction for all ALWRs consistent with the proposed 10CFR52.
EPRI Response:
We consider that ALWR technical submittals to the NRC provide sufficient justification for a design basis of 75% metal-water reaction rather than the 100% value which the staff intends to invoke.
We believe that before the NRC staff finalizes its position on this
- issue, a
thorough dialogue should take place between EPRI and NRC in which the technical basis for the ALWR Chapter 5 position of 75% metal-water reaction is discussed.
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