ML20244D781
| ML20244D781 | |
| Person / Time | |
|---|---|
| Issue date: | 04/03/1986 |
| From: | Rehm T NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | Kammerer C NRC OFFICE OF CONGRESSIONAL AFFAIRS (OCA) |
| Shared Package | |
| ML20238C237 | List:
|
| References | |
| FOIA-87-726, REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR NUDOCS 8604140479 | |
| Download: ML20244D781 (7) | |
Text
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u UNITED STATES
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NUCLEAR REGULATORY COMMISSION 1@/
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WASHINGTON, D. C J0555
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APR 0 3 '1986
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j MEMORANDUM FOR: Carlton C. Kamerer, Director Office of Congressional Affairs FROM:
Thomas Rehm, Assistant for Operations Office of the Executive Director for Operations
SUBJECT:
USI A-49 INFORMATION REQUEST
References:
(1) December 4,1985 Memorandim from Henry Myers to Carl Kamerer (2) December 30, 1985 Memorandum from Thomas Rehm to Carl Kamerer providing initial response to Reference 1-The staff was requested in Reference 1 to provide: 1)alistoftwoRT values for each PWR based on different correlations (the RT correlaINn in the 10CFR50.61 PTS rule and the proposed RT correlation 3 Revision 2 to4 Regulatory Guide 1.99); and 2) memoranda, ekbI that contain discussion of the differences in RT as calculated using the two correlations. The staff provided the memoYNda, etc. in Reference 2, but deferred providing the list of RT values until after January 23, 1986 when the licensee submittals were requiYNbythePTSrule.
When Reference 2 was prepared, the staff had not. received the submittals from the licensees, and therefore could not accurately" estimate the resources that would be necessary to review the submittals and perform the necesdry additional calculations. The staff had hoped that the requested information I
could be made available shortly after January 23, 1986. We have now received, from all licensees, inforneien regarding RT calculated using the NT correlation in the PTS rule % r'ined as RT This information involvss 60 affected vessels and includes as many as ikThlate and weld materfa?s for each vessel.
i We have found that the submitted information varies greatly in completeness.
Many licensees provided only the end-of-license RT values without specifying the bases for those values as required $fthe PTS rule'. That ' is,
the materials and fluence values used to calculate the RT values were not J
given in many licensee's submittals. Only after we receiNSth10information will we be able to review and accept or reject the RT values as submitted, and since the same material and fluence values are nebNsary as input to the proposed Regulatory Guide 1.99, Revision 2 RT correlation, we also will be able to determine RT valuespredictedbhDIhatcorrelationonlyafterwe j
receivethisinformatioYDT N
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The statf has a detailed review in progress to identify and obtain the additional infomation needed to justify staff acceptance or rejection of the licensee-submitted RT values. The staff is currently screening the submittals to determine dNh plants are expected to exceed the screening limit using input information fuHy acceptable to the staff. Detailed review will then proceed on tnose plants fir *.t such as Palisades, so that they can be informed as early as possible if flux reduction plans are required.
4 to this letter is 3 compilation.of the RT values as submitted l
by the licensees, based upon thre RT correlation spbfied in the PTS rule.
I These values have not been reviewed Nd accepted by the staff, and the list p
will very likely be changed by, the staff before acceptance.
l
?cference 2 provided you with a description of our plans regarding the RT correlation in the proposed Regulatory Guide 1.99, Revision 2.
SpecificaNy, T
Niosure / of Reference 2 (provided again as part of Enclosure 2 to this 19tter, for your convenience) gives a comprehensive description of the
- intar-relationship of the proposed new correlation to the PTS rule.
Enclosure 4 'of Rafarence 2 (alse cart of Enclosure 2 to this letter) provides the only projetion the staff has made regarding the dates when the first plants might exceed tt e screening limit if the proposed correlation were to be used for PTS screening limit purposes. The staff will be able to update this infonnation for each plant upor. completion of review of the inforination submitted by each i
plant regarding materials composition and fluence. As noted, a detailed review will proceed first on those plants most likely' to exceed the screening limit and will be cogleted on a plant-by-plant basis during the review period, with completion scheduled for all plants before Deccober 31, 1986.
However, any decision regarding incorporation of the proposed new correlation into the PTS rule must be made after:
- 1) the above described reviews of -
materials and fluence information have been completed; and 2) incorporation of the currently recuested public comments on the proposed Regulatory Guide 1.9% Rtvision 2.
Only after completion of both of these items will the final forn of the accepted correlation and the needed information for use in the correlation be known for each plant. At that time, a decision will be made regarding tne need for use of the new correlation for PTS pcrposes. We believe that time is available for completion of this process before any plant will cyceed the screening limit, based on either correlation.
We regret the length of time involved to complete this work, and the earlier triplication that the results could be available sooner, but the amount of i
material to be reviewed has proven to be quite extensive.
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i
4 -
1 I
1
-Q Dr. Roy Woods, the NRR staff Task Manager for PTS, would be pleased tc meet 1
with you 'and/or the Congressional staff members interested in this matter, at j
your convenience. He can be reached on 492-4712. Such a meeting would result i
in a much more efficient exchange of information than a further exchange of.
letters, and should be arranged if possible.
1 1
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l Thomas Rehm, Assistant for Operations j
Office of the Executive Director l
for Operations l
l Enclosures-i
- 1. Calculated Limiting RT Values
- 2. Potential Future ImpackThn PTS Rule l
I 1
1 l
1 v
(NOT REV!EWED OR APPROVED BY NRC)
CALCULATED LIMITING RT VALUES REPORTED PTS BY LICENSEES OF OPERATING PWRs IN RESPONSE TO THE PTS RULE,10 CFR 50.61 TAC PLANT (1) CALCULATED CALCULATED SCREfNING MARGIN LIMITING LIMITING CRITERION RT RT RT PTS PTS PTS REPORTED AT:
'F
'F
- F 59939 Arkansas, Nuclear One, Unit 1 12/4/08 251 300 49 59940 Arkansas Nuclear One, Unit 2 11/6/12 173 270 97 59941 Beaver Valley 32 EcoY 258 270 12 59942 Byron 32 EFPY 123 270 147 59943 Callaway 1 32 EFPY 161 270 109,_
59944 Calvert Cliffs 1 32 EFPY 238 270 32 59945 Calvert Cliffs 2 32 EFPY 199 270
-71 59946 Catawba 1 32 EFPY 104.2 270 165.8 59947 Cook 1 2/25/09 251 300 49 59948 Cock 2 2/25/09 199 270 71 59949 Crystal River 3 1/25/08 267 300~
33 59950 Davis Besse 1 3/24/11 217 300 83 59951 Diablo Canyon 1 40 EFPY 217 270 53 59952 Diablo Canyon 2 40 EFPY 228 270 42 59953 Farley 1 8/16/12 185 270 85 59954 Farley 2 8/16/12 220 270 50 59955 Fort Calhoun 1 EOL 242 270 28 (1)
Licensees reported these values in 3 different ways: (a) if a date is shown, the date to the end-of-license (EOL) and RT is calc iscalculatedasofE0LI$ameas(ulatedforthatEOLdate;(b)_ifEOL P
a) except E0L date was not listed in is shown, RT submittal; (bfif a number of effective full power years (EFPY) are shown, RT reported as of the accumulation of that power history, which would be after E8.
k
9
- 2'-
(NOT. REVIEWE0 OR APPROVED BY NRC)
TAC.
PLANT (1) CALCULATE 0 CALCULATED ~ SCAEENING MARGIN LIMITING-LIMIT 1NG' CFITERION RT RT E
PTS.
PTS PTS REPORTED AT:
- F
- F
- F 59956 Ginna EOL 267 300 33 59957 Haddem' Neck E0L 164.52 270 105.5 59958 Indian Point 2 10/06 214 270 56-59959 Indian Point 3 8/3/09 269-270 1
59960 Kewaunee 8/6/08 244 300 56~
59961 Main Yankee 8/21/08 243 300 57-59962 McGuire 1 32 EFPY 268-270 2
59963 McGuire 2 32 EFPY 195 300.
105
~
59964 Millstone 2 EOL 196.82 270 73.
59965 North Anna 1 2/18/11 225 270 45 59966 North Anna 2 2/19/11 227 270 43 59967 Oconee 1 11/6/07 231 270 39-59968 Oconee 2 11/6/07 292 300 8
i 59969 Oconee 3 11/6/07 220 300 80 59970 Palisades EOL 271-270
-1 59971 Palo Verde 1 32 EFPY 256* ~
270 14' 59972 Point Beach 1 7/19/07 241.7 270 28.3 59973 Point Beach 2 7/25/08 292.9 300-7.1 59974 Prairie Island 1 6/25/08 154 300 146 59975 Prairie Island 2 6/25/08 180 270 90 59976 Rancho Seco 10/4/08 265
- 270, 5
59977 Robinson 2 E0L 293.8 300-6.2 59978 Salem 1 9/25/08 255 270 15 59979 Salem 2 9/25/08 160 270 110 59980 San Onofre 1 2/27/07 260 270 10
- Design fluence was conservatively assumed
' (NOT REVIEWED OR APPROVED BY NRC)
TAC PLANT (1) CALCULATED CALCULATED' SCREENING MARGIN LIMITING.
LIMITING CRITERION PTS PTS-_
'F
'F
- F J
59981 San Onofre 2 11/15/22 141 270 129.
59982 San Onofre 3 2/16/22 129 270-141 59983 Sequayah 1 32 EFPY 240 270-30' 59984 Sequayah 2 32 EFPY 172 270 98-59985 St. Lucie 1
.7/10 230 270-40 59986 St. Lucie 2 4/23 179 270 91-59987 Sumer 1 2/21/13 155 270 115 59988 Surry 1 6/25/08
.244 300
'56 -
59989 Sur'ry 2 6/25/08 220'
.270
'50 59990 Three Mile Island 1 5/18/08 270 270 0
59991 Trojan 32 EFPY 177 270
'93-59992 Turkey Point 3 4/27/07 263 300 37 59993 Turkey Point 4 4/27/07 263-300 37 59995 Waterford 3 EOL 85 270 185 59996 Wolf Creek 1 3/11/25 140 270
'130 59997 Yankee Rowe 1997 239 270 31 60777 Zion 1 12/26/08 284 300 16 l
L 60778 Zion 2 12/26/08 238 270 32 l
i
ENCLCSURE ?.
3 POTENTI AL FUTURE ]MPACT ON PTS RULE f
0 DATE PLANT WOULD REACH SCREENING CRITER10N IF.RTPTS j
WERE CALCULATED PER R.G. 1.99, REv. 2
$(USING UPPER-BOUND CHEMISTRY FT. CALHOUN 1987 4
INDIAN POINT 2 1993 (COULD BE > E0L IF CHEMISTRY UPDATED) 1 PALISADES 1993 I
CALVERT CLIFFS 1993 1
INDIAN POINT 3 2001 PolNT BEACH 1 2001 i
MAINE YANKEE 2002 COOK 1 2006 ALL OTHERS E0L fire. It, /ffJ~
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.j AUG 1 11985 '
I 1
MEMORANDUM FOR: William.J. Dircks, Executive Director for Operations
]
FROM:
Harold R. Denton, Director Office of Nuclear Reactor Regulation
]
)
Robert B. Minogue, Director.
I Office of Nuclear Regulatory Research
SUBJECT:
RELATIONSHIP OF RT CORRELATION IN THE PTS l
RULE TO OTHER RT NDdORRELATIONS(YOURMEMORANDUM 0F JULY 30,1985fT 1
This memorandum explains the relationship between the recently promulgated PTS rule, Reg. Guide 1.99, Rev.1, and the recently proposed Reg. Guide.
1.99 Rev. 2.
This memorandum also contains RES and NRR's recommendations regarding how to proceed with the' proposed Reg. Guide 1.99, Rev. 2.
The recently promulgated PTS rule (published in the Federal Register on July 23,1985) contains its own RT correlation (to distinguish it from
- TS
)
other procedures for calculating R1pb. ), which the rule requires licensees to use when evaluating their t's RT for comparison to the rule-specified screening criterion.
The RT PTEorrelation in the PTS rule
)
was taken from a regression analysis perforiS[d on the PWR surveillance data 1
available at the time of the initial formulation of the PTS rule in late i
1982 (SECY 82-465. November 1982).
The RT correlation in Reg. Guide I
1.99, Rev.
1, dated April
- 1977, (whichNDjs used primarily to set pressure-temperature limits for normal operation), was taken from a bounding curve for the data available at that time, consisting of about 2/3 experimental data from research reactors and only 1/3 surveillance data from power reactors.
The staff deliberately chose not.to incorporate the Reg. Guide 1.99 RT correlation into the PTS rule because: 1) it was desired to have the latEl methods, acceptably conservative for PTS use, included in the PTS rule, and Reg. Guide 1.99, Rev. I was somewhat outdated at the time the PTS pr-M rule was drafted (late 1982); and 2) it was recognized that Reg. Guide 1.9g might be subject to repeated revision.because the technology is improving.
and the surveillance data base is continually. expanding, and it was desired not to subject the PTS screening criteria to constant changes, with the resultant variability in impact, and 3) it was believed necessary to include a prescribed method of calculating RT so that the overall-conservatism of the rule would not be upset by 1Nnsee or NRC changes to the RT [o preventcorrelation without giving serious consideration to the whole rule. ND confusion with RT correlations used for other purposes, the correlation in the final"NS rule 'was defined by the teru RT which is used for PTS screening.
PTS 166%L000 3
v p
1 1
l 2
AUG 121995 R
At the time the PTS rule was put into final fors, it was believed that the RT correlation it contained was adequately conservative for the purpose of Ntablishing a screening criterion.
During the relatively long time p
period consumed by the collegial process for rule promulgation, including two separate six month periods by the Commission for their review, the RT correlation remained frozen.
During that time, the NRC's evaluation of hwer reactor data and-improved correlation techniques continued, with p
the most recent product of that effort being the proposed Reg. Guide 1.99, Rev. 2 (recently presented to CRGR) containing RT correlations for use in evaluating pressure-temperature limits during 1 operations.
If the Rev. 2 correlations were used in place of the KT correlation, then nickel content welds.S would be predicted for a few kants that have high P
higher values of RT J
PT However, several features in the proposed Rev. 2 correlation will likely be the subject of considerable discussion and potential disagreement in the technical comunity when Rev. 2 is issued for public comment.
These features involve assumption of a different l
relationship for data fitting, division of the previous single data set into one data group for base materials and a separate data group for weld l
materials, and elimination of previously used data from research reactors.
They warrant comment by the technical comunity, and until the anticipated coments are resolved, we do not believe the conservatism of the present RT correlation in the PTS rule is called into question.
PTS 3
M r.
Accurate values of materials and fluence parameters are essential for the-meaningful application of either correlation.
For example,. based on l
current flux levels and the staff's limited information on assumed material composition, it was reported to the CRGR at its review of Reg. Guide 1.99, I
Rev. 2 on July 24, 1985 that the Reg. Guide, Rev. 2 correlation predicts the Ft. Calhoun plant would exceed the screening criterion in 1987 (the current RT Howevem we-understandScorrelation, by contrast, predicts a 1996 date).
t for cycle 10, beginning this fall, Ft. Calhoun will. Nad selected fuel assemblies containing several half length poison rods in the most effective outer row positions, which will cause a significant reduction in flux at the welds that are closest to the RT The effect of this change on the date of exceeding gg screening P
limits.
screening limit has not been quantified, but we believe it will be significant.
In addition, Quaha Public Power District has an effort underway to quantify the material composition of the critical welds.
Preliminary results indicate that it is likely that significantly lower values of RT and P
will be justifi able following this effort.
Accurate fg ence RT reEtion and materials data will be submitted in early 1986 as required by I the PTS rule. Using that data, we expect that the screening criterion will be predicted to be exceeded in the mid 1990's er later even if the Reg.
Guide, Rev. 2 correlation is used.
We reconnend that the proposed Reg. Guide 1.99, Rev. 2 be issued for public comment.
During the comment period, the PTS rule will remain in place.
Licensees and the technical comunity will consider the technical merits of the proposal, including its effect on their plaats for non-PTS purposes, chiefly as the basis for pressure-temperature limits, which must meet I
Appendix G,10 CFR Part 50.
3 AUGJ !!985 In addition. it.will be made clear in the package issued for public coment that the licensees may also consider and coment on the proposed change's effect on the calculated PTS risk at their plant, assuming the Rev. 2 correlation. if justified, would at some future time replace the RT [$
in the PTS rule.
Following resolution. of connents, o$
correlation general agreement is reached regarding the best way to calculate RT then it will be appropriate to re-evaluate the overall conservatism of Ne*
N PTS rule, and consider whether amendment of the PTS rule is desirable.
At that time, we will have available the plant-specific materials and fluence values that the PTS rule requires all PWR Licensees to submit early in 1986. This will allow us to much more accurately assess the effects on all plants that would result from a changeover to the Rev. 2 method.
We believe this is the best way to proceed, given the necessity of regulating in a conservative but realistic and consistent way while at the same time encouraging technical progress and improvement in basic understanding of complex phenomena such as material property changes (RTNDT) during neutron irradiation.
We believe this plan is consistent with the agreements reached at the meeting with you on August 2. 1985.
We therefore plan to revise the Reg.
Guide 1.99. Rev. 2 package to make clear the relationship of the Guide to the PTS Rule as described above, and then resubmit the package to the CRGR.
ctor 1
Office of Nuclear Reactor Regulation i
s&dGM Robert B. Minogue, Director Office.cf huclear Regulatoty Research f
u