ML16162A416
| ML16162A416 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Rancho Seco, 05000000, Crane |
| Issue date: | 01/18/1983 |
| From: | Vissing G Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR NUDOCS 8301240243 | |
| Download: ML16162A416 (23) | |
Text
11 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 January 18, 1983 Dockets Nos.
50-312, 289 & 270
SUBJECT:
SUMMARY
OF MEETING WITH SMUD, GPU AND DPC CONCERNING THE FLUX REDUCTION PROGRAMS FOR RANCHO SECO, TMI-1 AND OCONEE 2 ON JANUARY 14, 1983 Introduction 0
The meeting was held in Bethesda, Maryland on danuary 14, 1983, at the request of the NRC staff to discuss the licensees' programs for ensuring that the screening criterion for Pressurized Thermal Shock (PTS) for each of the subject facilities would not be exceeded. The agenda, which was to be followed, is provided in Enclosure 1. The attendees of the meeting are identified in Enclosure 2. The material for the licensees' presen tation is provided in Enclosure 3. The draft of the proposed staff Jetter to the licensees is provided as Enclosure 4.
Discussion The licensees provided the current status of each plant as of December 31, 1981.
The status included the peak fluence, the RTNP of the longitudinal weld nearest the peak fluence location assuming the ak fluence is at the weld (at least one weld is near to the peak fluence location), the rate of fluence increase at the peak fluence location assuming the current core configuration for Rancho Seco and the proposed core configuration for the next cycle (Cycle 6) for TMI-1, date when each plant would exceed the screening criteria assuming 80% capacity factor, and the expira tion of the operating license. It was noted that in each case the expira tion of the operating 1icense would be before each plant accumulated 32 EFPY's of operation. Oconee 2 was predicted to be able to operate to the eypiration of the license and 32 EFPY's without exceeding the screening criterion. Rancho Seco was predicted to have 14 calendar years of operation before reaching the screening criterion and TMI-1 was predicted to reach the screening criterion in approximately 20 years.
Rancho Seco, in scoping studies, was predicted to be able to extend the operating time of the plant another 5 to 6 EFPY's before reaching the screening criterion by implementing an in-in out core in the next cycle (Cycle 8).
Rancho Seco is committed to the in-in-out core in Cycle 8; however, details would not be available for at least 9 months. TMI-.
has not committed to the in-in-out core yet.
The licensees believe that other alternatives are available for delay of reaching the screening criterion. These include: (1) replacement of fluence calculations.at the welds, (2) refinement of RT shift correlation for B&W welds, (3) improvement of chemistry fo Dweld material and (4) determination of the real toughness of the vessel materials.
831 240243, 9301 PDR ADOCK 05000270
SMUD, DPC, GPU
-2 Conclusions.
The individual licensees (SMUD, GPU and DPC) indicated that they would document in letters within approximately three weeks, the information which was presented at the meeting in response to the draft proposed staff letter and provide a schedule oTSubmittals of information which could not be provided in detail with the letters. They indicated that they would not commit to alternatives which would challenge safetyfOr vessel operating limits.: 39 1
will..provid-e two reports which will provide material property date for all B&W plants. The staff would propose a letter which would acknowledge whatthe licensees would send anFWht was needed.
"ORIGINAL SIGNED BY:"
Guy S. Vissing, Project Manager Operating Reactors Branch #4 Division of Licensing
Enclosures:
- 1. Agenda
- 2. List of Attendees
- 3. Licensees' Presentation Material
.4. Draft of Proposed Staff Ltr. to Licensees cc w/enclosures:
See next page OFFICE)
- 1.
SURNAMEf........
I..
DATE.
NRC FORM 3.18 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
ORB#4:DL MEETING
SUMMARY
DISTRIBUTION Licensee:
GPUIJ, SMUD & DPC
- Copies also sent to those people on service (cc) list for subject plant(s).
L PDR ORB#4 Rdg JStolz Project Manager-GVissing Licensing Assistant-RIngram OELD Heltemes, AEOD IE SShowe (PWR) or CThayer (BWR),
Meeting Summary File-ORB#4 RFraley, ACRS-10 Program Support Branch
R. W. Klecker R. Rantala P. N. Randall J. Van Vliet E. L. Conner D. L. Basdekas J. C. McKinley Med El Zeftawy J. Milhoan C.'Johnson H. L. Ornstein K. Kniel R. Woods F. Schroeder E. D. Throm D. Fieno L. Lois
THERMAL SHOCK ISSUE DISTRIBUTION H. Denton/E. Case D. Eisenhut G. Lainas R. Vollmer W. Hazelton R. Mattson T. Speis T. Murley H. Thompson L. Shao R. Bernero E. Igne G. Knighton J. Austin J. Buzy J. Milhoan M. Vagins D. Ziemann D. Garner R. Johnson E. Goodwin T. Novak J. Clifford L. Lois E. Throm S. Chestnut A. Rubin C. Morris C. Serpan L. Shotkin W. Johnston A. Span T. Dunning C. Rossi J. Strosnider S. J. Bhatt R. Senseney A. Thadani S. Isreal Felix Litton
Enclosure I AGENDA FOR PTS MEETING WITH GPU, SMUD & DPC CONCERNING FLUX REDUCTION PROGRAMS FOR TMI-1, RANCHO SECO & OCONEE 2 1/14/83 o Current Status of Plant Fluence RTNDT RTNDT rate of increase
- date when will exceed screening PTND7 o
Flux. Reduction Option Considered
- description
- resulting flux reduction advantages and disadvantages, partulVarly power limits
- discussion of limit that causes power limit
- hot channel factor
- DNDR
- other assessment of desirability (from overall plant safety viewpoint) of relaxation of that limit.
o Alternatives to Flu Reduction for Delaying or Avoiding ReaChing the Screening Criteria archival mzaterials research otber o Other Aspects of PTS Program o Dissuesicns/Summary ATTENDANCE LIST FOR MEETING WITH SMUD, GPU AND DPC CONCERNING FLUENCE REDUCTION PLANS FOR RANCHO SECO, TMI-1 AND OCONEE 2 ON JANUARY 14, 1983 NRC GPU SMUD G. S. Vissing Jerry Delezenski T. H. Cogburn R. W. Klecker Ed Wallace John Janiszewski B&W4 R. Rantala Gordon Bond C. L. Whitmarsh P. N. Randall A. P. Rochino Frank Walters G. C. Lainas DPC C. J. (Skip) Hudson J. A. Van Vliet.
Bill Reckley Art Lowe John F. Stolz Robert Gill E. L. Conner NUS Corp.
AP&L D. L. Basdekas David Powell Daniel Spond J. C. McKinley NRC Calendar Med El. Zeftawy FPC Lynn Connor J. Milhoan E. H. Davidson Carl Johnson H. L. Ornstein Karl Kniel Roy Woods Frank Schroeder E. D. Throm Daniel Fieno Lambros Lois PRESENTATION TO NRC STAFF BY B&W OWNERS GROUP PLANNED FLUX REDUCTION TECHNIQUES THAT BENEFIT PTS FOR RANCHO SECO TMI-1 OCONEE-1I SPEAKER -
TOM COGBURN,. SMUD JANUARY 14, 1983 BETHESDA, MD
OBJECTIVE PROVIDE NRC STAFF WITH INFORMATION ON PTS FLUX REDUCTION PROGRAMS AND ALTERNATIVES
- CURRENT STATUS OF PLANTS AS OF 12/31/81 I VESSEL FLUENCE REDUCTION I ALTERNATIVE TO FLUX REDUCTION I B&W OWNERS GROUP PROGRAMS TO LESSEN PTS IMPACT PAGE 1
CURRENT STATUS OF PLANTS AS OF DECEMBER 31, 1981 RANCHO SECO TMI-1 0-II FLUENCE NVT X 10ig
.21
.18
.217/.287(1)
RTNDT OF 206 209 216 RATE OF FLUENCE INCREASE X10 PER EFPY
.046/.058
.0391.053
.036/,061 DATE WHEN WILL EXCEED SCREENING CRITERIA 1997 2003(2) 2010 EXPIRATION OF 0. L.-
2008 2008 2007 LICENSEE VALUE/NRC VALUE (2) ASSUMES 18 MONTH IN-OUT-IN LOW LEAKAGE FUEL CYCLE STARTS IN CYCLE 6 PAGE 2
Reductions in Peak Reactor Vessel Fluence in TMI-1 3.0 INITIAL PREDICTIONS (FSAR) 2.5 C...
2.0 PREDICTED BASEDON C
OWNERS GROUP INTEGRATEU RV SURVEILLANCE PROGRAM THESE DATA WERE USED IN
=
A THE TMI-1 ANALYSIS.
1.5 Jm W
C4
- U,.
- 1. SC.RENING LIMIT FOR, 870*F PREDICTED BASED ON 0.5 LOW LEAKAGE FUEL CYCLE ASSUMED CONVERSION TO LdW LEAKAGE FUEL CYCLE 0
4 8
12 16 20 24 28 32 Effective Full Power Years (EFPY)
Reductions in Peak Reactor Vessel Fluence in Rancho Seco 2.5-C=C FSAR PREDICTJON 2.0 PREDICTJON BASED ON 1st 3*CYCLES &
PS-E CAPSULE 1
3 PREDICTED BASED ON IN CREENING LIVJT FOR 270 r
OUT-IN FUEL CYCLE & RSI-E CA_
CRENIN LIMT FR 2D rCAPSULE ASSUMING CONVE 510A TO IN-IN-0UT F EL CYCLE 0
4 f
12 1E 20 24 28 32 Effective Full Pcoer Years (EFPY)
VESSEL FLUENCE REDUCTION THROUGH FUEL CYCLE MANAGEMENT IN-OUT-IN SHUFFLE OF FRESH FUEL I LBP USED FOR PEAKING CONTROL I ~30% REDUCTION IN PEAK FLUENCE I NO IMPACT ON DNBR, LHR, PLANT SAFETY IN-IN-OUT SHUFFLE OF FRESH FUEL
- SMALL INCREASE IN PEAKING OVER IN-OUT-IN I ESTIMATED REDUCTIONS IN PEAK FLUENCE OF-20%
I EXPECT IMPACT ON CORE THERMAL PARAMETERS CAN BE OFFSET WITH IMPROVED ANALYSIS TECHNIQUES AND/OR SOME RESTRICTION.F REACTOR MANEUVERING CAPABILITY I PLANT SPECIFIC ANALYSIS WOULD BE REQUIRED TO ASSURE FLUX REDUCTION AT OTHER THAN PEAK LOCATION PAGE 5
Typical Fuel Assembly Loading Patterns Typical Out-In Loading Typical Low (1/8 Core)
Leakage lnOut.ln Loading (1/8 Core)
Full Core F
F F
F F
F F F FFF F
F F
[ff Fresh Assembly Once Used Assembly
[1 Twice Used Assemhly
FLUENCE REDUCTION TECHN10HES GLOBAL FLUENCE REDUCTION OUT -
IN (BASE)
IN - OUT -
IN (IMPLEMENTATION)
IN -
IN -
OUT (EVALUATION IN PROCESS)
LOCAL FLUENCE REDUCTION DEPLETED ASSEMBLIES DUMMY ASSEMBLIES
Longitudinal Weld Locations to Azimuthal Fluence Profile OUTLET NOZZLE x
VESSEL (2)
INLET NOZZLE (4) x
.6 9.7
.7
.70 CORE REGION
.70
.8 14.80 WF-70 WELD
.84 FLUENCE NORMALIZED.
1.0 T PEAK FLUENCE
.99 LOCATION 12*
4.10 WF-29 WELD
.93
.seco Azimuthal Flux Profile Normalized to Peak Flux Location for Cycles 1 Through 3 Average 1.0
.7 w-29 w-70
.5 0 4 8 12 16 20 24 28 32 36 40 44 48 Azimutnal angle. oegrees from major axis
ALTERNATIVES TO FLUX REDUCTION FOR DELAY OF REACHING SCREENING CRITERIA REFINEMENT OF UNCERTAINTIES IN INITIAL RTNDT VALUES IMPROVEMENT OF CHEMISTRY FOR CRITICAL MATERIALS BAW-1511P, OCTOBER 1980 BAW-1500 REFINEMENT OF VESSEL FLUENCECALCULATIONS TO FURTHER REDUCE UNCERTAINTY DEVELOPMENT OF RTNDT SHIFT CORRELATION FOR B&W WELD METAL PAGE /0
B&W OWNERS GROUP PROGRAMS TO LESSEN PTS IMPACT MARGIN ASSESSMENT PROGRAMS PLANT SPECIFIC PTS ANALYSES EPRI MIXING TEST/ANALYSIS METHODS I
IMPROVED FRACTURE MECHANICS TECHNIOUES I
IMPROVED FRACTURE TOUGHNESS CORRELATIONS UTILIZE PERTINFNT RESEARCH DATA FROM OTHER INDUSTRY PROGRAMS RJSK REDUCTION PROGRAMS I
ENHANCED ISI I
OPERATING PROCEDURES CHANGES (ATOG)
PTS TRAINING I
PLANT MODIFICATIONS I
OPERATING EXPERIENCE FEEDBACK (TAP)
SUMMARY
TIME TO EXCEED SCREENING CRITERIA IS>14 YEARS FLUX REDUCTION (IN-OUT-IN FUEL CYCLE) IN PLACE AT R-S AND OCONEE 2 FLUX REDUCTION (IN-OUT-IN) PLANNED FOR NEXT TMI-1 REFUELING FURTHER FLUX REDUCTION (IN-IN-OUT FUEL CYCLE)
UNDER CONSIDERATION FOR R-S AND TMI-1 NEW RTNDT CORRELATION FOR B&W RV MATERIALS OTHER PROGRAMS IN PROGRESS TO FURTHER REDUCE PTS RISK Draft 10 CFR 50.54(f) letter to category of licensees who have a plant where a flux-reduction factor between 2 and 5 would allow operation to end-of-plant life without exceedino RT screening criterion.
NDT sreigciein
Dear At the December 9,
1982 meeting of the Nuclear Regulatory Commission, the staff presented results of its Pressurized Thermal Shock (PTS) studies as described in SECY 82-465. The Commission subsequently directed the staff to.
develop a Notice of Proposed Rulemaking that would establish an RT NDT screening criterion, require licensees to submit present and projected values of RTNDT, require early analysis and implementation of such flux reduction programs as are reasonably practicable to avoid reaching the
.screening criterion, and require plant-specific PTS safety analyses before plants are within three calendar years of reaching the screening criterion.
The staff's proposed screening values are an RTNDT of 270'F for plates and axial welds, and 300'F for circumferential welds. The Commission also noted and concurred that the staff should meet with licensees of4 plants for w:hich near-term flux reductions of factors of two to.five would ensure that the screening criterion would not be exceeded throughout service life, to determine the licensees' plans for such programs, and propose issuance of 10 CFR 50.54(f) letters to such licensees, if appropriate, following the meetings.
Based on the information currently available to us, we believe your plant(s), (name),-is (are) in that category.
Accordingly, pursuant to 10 CFR 50.54(f) you are requested to furnish, no later than March 1, 1983, the following information regarding your plans for such flux reduction.
(2) Provide your assessment of the fluence experienced to date by the welds and plates in your pressure vessel, the rate of increase expected assuming future fuel cycles to which you-are already committed, and a detailed description of the bases for the above (including surveillance capsule data and analysis methods, and generic methods or correlations used).
-2 (2) Using the above fluence information, provide your assessment of the RTNDT presently existing in your pressure vessel welds and plates utilizing the methodology outlined in Appendix E to Enclosure A of SECY-82-465, and the expected future rates of incerase, and the expected dates when the applicable proposed screening criterion will be exceeded.
(3) Provide a description of the flux reduction options that you have.
considered for your plant. Include for each option:
(a) Description of fuel management and/or fuel removal and/or fuel replacement with dumy elements, showing core maps for future cycles; (b) Quantitative assessment of resulting flux reduction to critical welds and plates; (c) Parametric study showing future RTNDT values resulting from both the earliest practicable implementation of the cption, and from the latest possible implementation of the plan that will still avoid exceeding the RTNDT screening criterion at end-of-life; (d) Discussicn of advantages and disadvantages of the option, particularly emphasizing power reductions caused by the option. With respect to power reduction, discuss the magnitude of the reduction and the particular limit (e.g., hot channel factor, DNBR, etc.)icausing the power reduction.
Also analyze how much relief would be necessary (with respect to the particular limit) to allow full power operation, and assess whether such relief would be an improvement to overall plant safety (considering LOCA, PTS, transients, etc.).
(4) Discuss -any alternatives you may be considering to flux reduction that will result in delaying or avoiding exceeding the RTNDT screening criterion. These would include topics such as archival materials research, plans to sample and analyze as-built materials, etc.
-3 We require that the above information be provided by March 1, 1983 as we wish to have all feasible flux reductions implemented as early as possible in order to achieve maximum safety benefit. We may request a meeting with you to discuss your options.and plans after we have reviewed the above requested information.
OMB clearapce is not required for this requestsince it is being transmitted to nine or fewer addresses.
Harold R. Denton, Director Office of Nuclear Reactor Regulation
UNITED STATES
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