ML19209C751
| ML19209C751 | |
| Person / Time | |
|---|---|
| Issue date: | 09/13/1979 |
| From: | Thadani A Office of Nuclear Reactor Regulation |
| To: | Hanauer S Office of Nuclear Reactor Regulation |
| References | |
| FOIA-80-587, REF-GTECI-A-09, REF-GTECI-IS, REF-GTECI-SY, TASK-A-09, TASK-A-9, TASK-OR NUDOCS 7910180249 | |
| Download: ML19209C751 (13) | |
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[m'o r1c UNITED STATES
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c NUCLEAR REGULATORY COMMISSION c
WASHINGTON, D. C. 20556 p#
, men TAP A-9 MEMORANDUM FOR:
S. H. Hanauer, Director Unresolved Safety Issues Program FROM:
A. Thadani, Task Manager, A-9
SUBJECT:
NRC - BWR 3 OWNERS - GE ATWS MEETING
SUMMARY
A meeting was held in Bethesda on Septerrter 7,1979 between representatives of the NRC staff, BWR 3 owners and the General Electric Company (GE). The purpose of the meeting was to describe the staff plans for resolution of the ATWS issue and to provide the necessary background information so that the BWR 3 owners could develop a schedule for submittal of the infonnation needed to verify adequacy of Alt. #3 fix (see NUREG-0460, Vol. 3).
At the outset the staff summarized the recent history of plans and actions to resolve ATWS. This surmary covered the Early Verification described in NUREG-0460, Vol. 3 RRRC review results, 2/15/79 Mattson letter to vendors requiring verification analyses, industry and vendor meetings to curther group (in 3 Bins) the 2/15/79 letter responses, TMI-2 impact meeting with the PWR industry, and the discussions on BWR 4/5/6 plants.
The staff reiterated their commitment to proceed as planned to resolve this safety issue and asked that the industry provide the necessary aupprting analyses.
The industry comments are su warized below:
- 1) All BWR 3 owners are represented at the meeting.
- 2) Need specific details of f4RC needs,
- 3) Why were BWR 3 plants classified differently than the WASH-1270 classification (protection system fix + plant specific review).
4)
NRC had not responded to the alternative 2 fix proposal (NEDE-24669) for BWR 3 plants.
In support of their contention that requiring Alt. #2 fix only for BWR 3 plants would not significantly increase societal risks, they compared (enclosure
- 2) the risk (potential for severe consequences) using NUREG-0460, Vol. 3, Appen-dix F assumptions for the following two cases.
1177 548
$' 9 7910180
S. H. Hanauer $ty la als Case 1) 4 Reactors fixed per alternative #2 58 Reactors fixed per alternative #3 Case 2) 12 Reactors fixed per alternative #f (8 BWR 3 plants added) 50 Reactors fixed per alternative #2 For these two cases they showed that the chance in risk is only a factor of 1.4.
However, the staff noted the following deficiences in this comparison.
a) Some plants are anticipated to be fixed up per alternative 4 and thus result in great.er change in risk if the 8 BWR 3 plants are put under alternative #2.
b) Assumption of no additional changes to plants in alternative #2 may not be valid.
The staff also noted that the plant specific analyses and review would also impact NRC as well as industry resources. The owners suggested that they would provide generic analyses (See Enclosure ?) with plant specific differences to be addressed by individual licensees.
The staff poia+ed to incompleteness of proposed submittal and noted that the required infonnation was described in the 2/15/79 Mattson letter and further elaborated at the August 10, 1979 meeting with GE and the BWR 4/5/6 owners (August 10 meeting minutes were given to BWR 3 owners). The BWR 3 owners agreed to a telephone conference between GE (H. Pfefferlen), the owners (L. Del George) and the NRC (A. Thadani) to further describe the scope of the needed inforration.
The staff also noted that submittal of information characterized as Bin #1 and Bin #2 beyond January would likely conflict with our schedule for issuing an ATWS rule.
In summary the industry noted that:
(Alt. 3 fixes described in NUREG-0460, Vol. 3 may not yield the same level of protection for some BWR 3 units because of design differences such as lower relief capacity, HPCI isolation signals and unpiped safety valves). The impact of potential additional plant modifications because of these differences may be greater than automating SLCS.
- 2) BWR 3 ATWS implementation (Enclosure 4) should be consistent with WASH-1270, similar to BWR 1/2, and based on value/ impact assessment.
- 3) One needs to get away from analyses and that the BWR 3 owners have some toughts on improvements beyond alt. #2 which could be implemented but they are concerned with automating SLCS.
- 4) Industry recognizes the need for submittal of responses to the questions in the 2/15/79 Mattson letter.
1177 549
S. H. Hanauer SEP 13 I973 The meeting was concluded with the following coments by the staff:
- 1) The staff has decided, after considerable thought and debate, that BWR ?
plants should be modified in accordance with the Alt. #3 fix unless techni-cal reasons dictate otherwise. The staff would be interested in getting some details on the owners thoughts on improvements beyond Alt. #2 fix.
- 2) The staff needs analyses to verify that the Alt #3 fix provides the needed improvements in protection from ATWS events.
- 3) The staff considers BWR 3 and 4 plants of equally high priority and thus would need the information on BWR 3 plants to be supplied a schedule similar to that for BWR 4 plants.
An attendance list is given in enclosure 1.
P (Q k.h 9fD
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A.
hadani, Task M4. nager A-9 cc: ATWS Distribution Meeting Attendees 1177 550
ENCLOSURE 1 ATWS Meeting with BWR 3 Owners - 8/7/79 Attendance List A. Thadani NRC/ DSS F. Cherny NRC/ DSS /MEB J. P. Cagnetta Northeast Utilities Joseph Gonyeau Northern States Power Wade Larson Boston Edison Company Louis Del George Commonwealth Edison Co.
Gerald H. Neils Northern States Power Company Cordell Reed Commonwealth Edison Don Edwards Yankee Atomic Electric Company Anthony Bournia NRC/DPM Morton R. Fleishman NRC/SD/EMSB H. C. Pfefferlen GE R. Buchholz H. Vander Molen NRC/ DOR /RSB S. H. Hanauer NRC M. c inivasan NRC/ DSS /ICSB r
K.. Parczewski NRC/ DOR /RSB K-tin D. Desai NRC/ DSS /MEB 1177 551
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S-P00R E 8lNAL RISK EVAll1 ail 0ll (BASED ON HUREG-0460, VOLUME 3, APPENDIX F) 62 BHR'S 22 BWR'S PRIOR TO CALVERT CLIFFS #2 4 BWR 1/2 8 BWR 3 (INCLUDING VERMDNT YANXEE)
VOLUPE 3 REC 0ffBDS 4'BWR 1/2 PLANTS FOR ALTERNATE 2 AND FOR CONSERVATISM ASSUE OTHER 58 PLANTS IN ALTERNAT THEN TOTAL RISK IS (4R)(4X10-5/RY) + (18R)(6X10-6/RY) +(40R)(1X10 6'.7X10-4/Y
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RECATEGORIZE 8 BWR 3 PLANTS ALONG WITH BUR 1/2 INTO ALTERNATE 2 (12 PLANTS) AND ALL OTHER PLANTS INTO ALTERIMTE 3 (50 PLANTS).'
TOTAL RISK IS
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(12R)(4X10-5/RY) + (10R)(6X10-6/RY) + (40R)(1X10
=
9,'9X10-4/Y
=
JW-3:-15-79
fu c loz& 3 BWR/3 ALTERNATE 3 REPORT REPORT TO ADDRESS:
e MSIV, TURB, TRIP AND IORV REDY CODE (REDY/0DYN COMPARISON IN BWR/4/5/6 REPORT SAME ASSUMPTIONS / INITIAL CONDITIONS AS BWR/4/5/6 e
RADIOLOGICAL ASSESSMENT (LIMITING EVENTS) e SRV LOADS (LIMITING EVENTS) e FUEL INTEGRITY ASSESSMENT (LIMITING EVENTS) e CONTAINMENT TEMP. & PRESS, e
SLC INJECTION POINT SCHEDULE - 12/79 1177 553 I
e f
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BWR/3 ALTERNATE 3 REPORT BWR 4/5/6 REPORT WILL PROVIDE BASIS FOR:
ANALYTICAL MODELS, ASSUMPTIONS, PARAMETERS PRELIMINAdY ATWS MITIGATIONS SYSTEM DESCRIPTION S/RV LOAD IF APPLICABLE RADIOLOGICAL ASSESSMENT QUENCHER PERFORM,1CE SENSITIVITY STUDIES IF APPLICABLE SIMILAR TO APPROACH ON BWR 3 ALTERNATE 2 lI77
$54
BWR/3 ALTERNATE 3 REPORT SUPPLEMENTARY REPORT TO ADDRESS:
SENSITIVITY (LIMITING TRANSIENTS)
FOOL TEMP VESSEL PRESSURE WATER LEVEL FUEL INTEGRITY SCHEDULE - 3/80 1177 555
^ ^ ^ ^ -
A
be tcouv t-j BWR 3 CLASSIFICATI0tl JUSTIFICATION FOR CLASSIFYING BWR 3 WITH ALTERNATE #2 PLANTS e HISTORICAL TREATMENT e VALUE/ IMPACT e RISK 1177 556
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PREVIOUS HISTORY WASH 1270 (1973)
BWR 1/2/3* CATEGORY C F! ANTS CASE-BY-CASE EVALUATION -
N0 HARDWARE REQUIRED DISCUSSIONS WITH STAFF GENERIC ANALYSIS FOR (1974)
BWR 4/5/6 (CATEGORY "B")
CASE-BY-CASE EVALUATION CATEGORY "C" PLANTS NED0 20626 (1974)
CATEGORY '.'B" PLANTS ONLY DECEMBER 1975 NRC STATUS CATEGORY "B" PLANTS ONLY REPORT NUREG-0460 VOL I/II (1978)
SYSTEMS EVALUATION BASED ON WASH 1270 AND DECEMBER 1975 STATUS REPORT.
NO VALUE IMPACT FOR BWR 1/2/3.
NUREG-0460 VOL 3 BWR 1/2 - CASE-BY-CASE EVALUATION (ALTERNATE 2)
BWR 3/4/5/6 - GENERICALLY (ALTERNATE 3)
- INCLUDING VERMONT YANKEE 1177 557
VALUE/ IMPACT e BWR 1/2 STAFF EXCLUDES FROM ALT. #3 BECAUSE " ENGINEERING, COST AND RISK ANALYSES... IN NUREG-0460 ARE NOT GENERALLY APPLICABLE".
STAFF INCLUDES IN ALT.
- 3 BASED ON NUREG-0406 e BWR 4/5/6 VOL. 1 8 2 ASSESSMENT.
APPLICABILITY OF NUREG-0406 ENGINEERING, COST e BWR 3 AND RISK ANALYSES TO THE BWR 3 HAS NOT BEEN DEFINED.
VALUE/ IMPACT NEEDED FOR BWR 3 1177 558
ELSE PRESENTLY STAFF PLACES 4 BWR 1/2 PLANTS IN ALTERNATE 2.
ASSUMING ALL OTHER PLANTS ARE IN ALTERNATE 3 AND USING NUREG-0460, VOLUME 3 APPENDIX F RESULTS IN OVERALL PROBABILITY OF 7X10-4/ YEAR WHICH BY DEFINITION IS ACCEPTABLE CATEGORIZING 8 BWR 3'S INCLUDING VERMONT YANKEE INTO ALTERNATE 2 RESULTS IN AN OVERALL PROBABILITY.0F 9X10-4/ YEAR WHICH IS A NEGLIGIBLE INCREASE 11ll 559
CONCLUSION
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BWR 3 ATWS IMPLEMENTATION SHOULD BE:
e CONSISTENT WITH WASH 1270 e EVALUATED'SIMILAR TO BWR 1/2'S e BASED ON VALUE/ IMPACT ASSESSMENT 1177 560 E