ML19210B873
| ML19210B873 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 08/22/1977 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Herbein J METROPOLITAN EDISON CO. |
| References | |
| NUDOCS 7911120569 | |
| Download: ML19210B873 (7) | |
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1)ocket' NRC PDR AUG 22 N L PDR ORB #4 Rdg.
RWReid RIngram Cocket hos.: 50-289 GZwetzig and 50-320 JWetmore OELD OI&E(3)
DEisenhut Metropolitan Ecison Company TBAbernathy ATTH: Mr. J. G. Herbein JP. Buchanan Vice President TCarter P. O. Box 542 ACRS(16)
Reading, Pennsylvania 19603 File Gentlenen:
RE: THREE MILE ISLAND NUCLEAR GENERATING STATION The Standard Technical Specifications (STS) for each NSSS vencor type plant currently contain a bases section that provides background information and technical support for each specification. The informa-tion in the bases has proven to be useful in enabling plant operators, and others involved in the operation or ifcensing activities of a facility, to better understand the reasons for the various specifications.
It has also been useful to both licensees and the NRC staff as a technical summary of the plant design bases and the interrelationship of many of the safety considerations associated with operation of a plant.
Consequently, the bases have served not only as support for the STS, but as training material for licensee personnel and, to some extent, as a source of background material for the NRC staff in rev'iewing certain licensing actions. We believe a number of benefits could be gained if the STS bases were upgraded, Among the cajor benefits we foresee are:
1.
Technical Specification change requests could be prccessed in less time and with reduced manpower since much of the detailed inforraation affecting consideration of the pending change would be readily available in the bases. Since a large anount of effort is expended by each of our staffs in researching and reviewing all of the factors influencing a typical change request, we believe the potential savings in manpower effort resulting from this improvement would be significant for both licensees and the NRC.
2.
The relationship and effect of each of the factors influencing gy the selection of technical specification limits and requirenents would be nore clearly understood by users of the documents f,
J thereby increasing the usefulness of the specifications as cperator trair.ing material for your staff.
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Metropolitan Edison Ccepany 3.
Questions involving interpretation of the technical specifications, that occur from time to time, could be more easily resolved between licensees and the Office of Inspec? :on and Enforcement.
4.
The continuity of detailed technical infomation would be preserved in a systematic manner throughout tne facility lifetime thereby minimizing the adverse tapact of transfer or reassigment of individuals who may possess detailed knowledge related to tne evolution of the facility specifications.
Accordingly, we are initiating a program to upgrade the bases section of each generic STS. The progran includes upgrading the bases for Section 2, " Safety Limits and Limiting Safety System Settings", and Sections 3 and 4, " Limiting Condition for Operation" and " Surveillance Requirements". The objective of the program is to provide a more cefinitive and detailed rationale for each specification in these sectiens. This will recuire some reorganization of the infomation currently in the bases, as well as the development of additional information. A suggested format for and the 1;ype of information that we believe should be considered for inclusion in the upgraded STS bases is provided in Enclosure 1.
As part of our continuing policy of involving the industry in the further refinenent and improvenent of the STS's, we are inviting your participation in this effort as one of those facilities either already in operation or scheduled for operation with STS in the near future. Your HSSS vendor is also being invited to participate.
Upon completion, we will incorporate the revised bases into the STS for all future operating licenses. STS facilities in operation may then elect, at their option, to upgrade their existing technical specification bases to reflect this improvement. This effort is not expected to have any effect on completion of Technical Specifications now in preparation for units scheduled for operation in the near future.
We would appreciate your letting us know if you are willing to participate so that we can schedule a meeting with you, your venacr, and the other participating utilities at some time in the near future.
At this meeting, we could discuss the objectives of the program, and mutually develop plans for accomplishing the upgrading of the bases in a systematic manner.
In the event you feel it would be beneficial to fom a generic users group, a list of those facilities being invited to participate in this program, and who utilize the same NSSS vendor, is provided for your information in enclosure 2.
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Metropolitan Edison Company If you have any questions regarding this program, or care to discuss it further, please contact us.
In any event, we would appreciate hearing fron you within the next few weeks.
Sincerely, Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors
Enclosures:
1.
Infomation to be Provided for Upgraded STS Bases Progran 2.
List of Facilities Requested to Participate cc w/ enclosures:
See next page f
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Metropolitan Edison Company cc:
G. F. Trowbridge, Esquire Shaw, Pittman, Potts & Trowbridge 1800 M Street, N. W.
Washington, D. C.
20036 GPU Service Corporation Richard W. Heward, Project Manager Thomas M. Crimmins, Jr., Safety and Licensing Manager 260 Cherry Hill Road Parsippany, New Jersey 07054 Pennsylvania Electric Company Mr. R. W. Conrad Vice President, Generaticn 1001 Broad Street Johnstown, Pennsylvania 15907 Mr. Weldon B. Arehart, Chairman Board of Supervisors of Londonderry Township RFD#1, Geyers Church Road Middletown, Pennsylvania 17057 Miss Mary V. Southard, Chairman Citizens for a Safe Environment P. O. Box 405 Harrisburg, Pennsylvania 17108 Government Publications Section State Library of Pennsylvania Box 1601 (Education Building)
Harrisburg, Pennsylvania 17126
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ENCLOSURE N0. 1 INFORMATION TO BE PROVIDED FOR UPGRADEDSTSBASESPROGRAM/
Fundamentally, the information in the bases for each specification shculd (1) describe why the specification is needed (i.e., identify its purpose), (2) explain why the quantitative values used as limits in the specification were chosen, and (3) indicate the margins of safety provided by the limits.
To present this information in a clear and orderly fashion, a standardized format for the bases for each specification should be used.
In our view, the standardized format should contain three basic parts:
(1) Purpose, (2) Supporting Information, and (3) Margin of Safety.
The information presented in each part should be in the form of concise summary statements and/or tabulations of data that serve to support the specification.
The type of information that should be provided is delineated below.
1.
PURPOSE The purpose of the specification should be stated in terms of the conditions the specification has been formulated to establish or maintain. Any multiple purposes should be identified.
2.
SUPPORTING INFORMATION Information to support the quantitative values of the limits established by the specification shculd be provided in this part. The limiting value(s) of the specification should be supported in terms of the most restrictive plant variables or conditions used to establish the limit. -In addition, pertinent information associated with the specification that relttes to plant features or operating considerations should be prsvided.
The manner in which the surveillance requirements ensu"e that the limits are maintained should be stated for survei lance whose intent is not obvious.
The assumptions relating to the establishment of the limiting value or condition should be stated in terms of each of the factors applicable to the specification.
These factors should, where possible, include:
1 This program includes upgrading the bases for only Sections 2, 3, and 4 of the STS.
Sections 5 and 5 are not included.
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a.
Assumptions of initial operating conditions.
b.
Assumed allowances for instrument bias factors including error, drift and calibration considerations, c.
Assumed uncertainties associated with measurement of physics related parameters such as void and moderator temperature coefficient, rod worth and boron concentration.
d.
Assumed allowances related to uncertainties in tank volumes including considerations of unusable fluid volumes resulting from tank physical characteristics (vortexing, suction pipe elevation). Assumed minimum pump flow and discharge pressure characteristics including allowance for expected degradation.
3.
MARGIN OF SAFETY The rescitant margin of safety obtained from consideration of the above factors should be provided in a definitive manner such that the relationship between specification limiting values and any related safety analyses assumptions is clearly established.
Methodology such as probabalistic or statistical analyses techniques or the use of cumulative addition of factors in a non-conservative manner should be stated.
Conformance with applicable provisions of Regulatory Guides, General Design Criteria or the Code of Federal Regulations should also be stated where applicable.
Much of the information for part (1) and to a lesser extent, part (3) of the standardized bases format is currently provided for a number of soecifications in the STS.
A reorganization and expansion of this information is what is sought. On the other hand, the information relating to assumptions which is to be provided in Part (2) would be new for most of the specifications.
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ENCLOSURE NO. 2 LIST OF FACILITIES RECUESTED TO PARTICIPATE Ir1 UPGRADED STS BASES PROGRAM NSSS VENDOR SABC0CK & WILCOX Arkansas Unit 1 Three Mile Island Unit 2 Midland Units 1 and 2 Washington Nuclear 1 Crystal River Unit 3 Davis-Besse Unit 1 e
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