ML20125C824
| ML20125C824 | |
| Person / Time | |
|---|---|
| Issue date: | 10/01/1979 |
| From: | Hanauer S NRC - TMI-2 UNRESOLVED SAFETY ISSUES TASK FORCE |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| REF-GTECI-A-09, REF-GTECI-SY, TASK-A-09, TASK-A-9, TASK-OR NUDOCS 8001110565 | |
| Download: ML20125C824 (5) | |
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UNITED STATES IJ'*I 1 i NUCLEAR REGULATORY COMMISSION
- { q th' ,E WASHINGT ON, D. C. 20555
$[Rf/ **"* OCT 1 1379 NOTE T0: H. R. Denton, Director Office of Nuclear Reactor Regulation ,
FROM: S. H. Hanauer, Director Unresolved Safety Issues Program
SUBJECT:
ATWS Here is a draft of a letter to all utilities telling them the great importance we attach to obtaining timely and complete infonnation from them on ATWS al-ternatives. Would you be willing to sign such letters? Have you any comments ;
on the draft?
0( /
/$ S/ H. Hanauer, Director
.))nresolved Safety Issues Program cc: E. Case l R. Mattson F. Schroeder .
A. Thadani fi. Aycock 90019348 1
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800111o 5 65
i Letter to be sent by NRR to same Utilities that received letters iri l' arch.
Docket N=bers for All Plants operated and/o* under constru: tion for the Utility should be referenced on letter.
Dear.(Mr.) (Ms.) (Mrs.) Utility President:
This past March, the NRC transmitted to you a copy of Volume 3 of NUREG-0460,
"/u:LI !;e:t=J Trir:sients 'r.'ith:ut S:rir 'or Lyht cter Recctors" (f.T!!S) cnd :
copy of an NRC letter that was sent this past February to each of the four nuclear reactor vendors. The letters to the vendors contained requests for information needed to perform generic analyses related to ATWS.
As we pointed out in our Marc.h letters, the generic analyses we requested were intended to confirm that the modifications proposed by the NRC staff for various classes of LWR design's would in fact accomplish the degree of ATWS prevention and mitigation described by the staff in its report. We also pointed out that we had chosen to work directly with the vendors in obtaining this information in an effort to conserve both NRC and industry resources. We requested that !
utilities cooperate with the vendors in performing the requested analyses.
Shortly after sending the letters to the vendors, the NRC Staff met with repre-sentatives of each of the NSSS vendors and many Utility representatives in Bethesda on March 1,1979. The meeting was called to discuss the "early verifi-cation" approach in which we planned to use generic analyses as the basis for f
rulemaking. We hoped thereby to avoid costly and unnecessary repetitive analysis l for individual plants. At the meeting, a tentative schedule was agreed to for generic analyses for each class of plants to be provided in three separate packages to be submitted May 1, September 1, and December 1,1979.
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hmediately following the March 1 meeting, the NRC staff net separately with each of the NSSS vendors and agreements were made as to the minimum information to be supplied in the May 1 package. Also, as noted above, copies of the ATWS staff report and the generic analyses questions were transmitted to the D *
- lD lD 91' Utilitis:.
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Because of the heavy On March 28, 1979 the Three Mile Island accident occurred.
expenditure of NRC resources required for Three Mile Island related activities, essentially no staff effort was applied to the ATWS issue for three months or j l
so following the accident. T,here was also a substantial reduction in effort on !
the part of the PWR industry .during that period, and some reduction for BWRs.
In June,1979, the NRC Office of Nuclear Reactor Regulation was temporarily reorganized. Within this interim organization a group was assigned under the !
direction of S. Hanauer to work on the 19 Unresolved Safety Issues as designated !
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by the Comission and reported to Congress this past January in NUREG-0510.
ATWS is one of these 19 issues. l A preliminary NRR Staff review suggested that, for PWRs, the Three Mile Island accident raised new questions with regard to the appropriateness and adequacy of the resolution of ATWS as proposed by the Staff in Volume 3 of NUREG-0460.
For BWRs, the staff has concluded that the technical impact of Three Mile Island was minimal and that the completion and review of the generic analyses for BWRs as specified in March should proceed as expeditiously as possible.
A meeting was held in Bethesda on July 25, 1979 to discuss, with representatives of PWR utilities and designers, considerations arising from the Three Mile 90019.;50
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. m Island accident that might be relevant to ATWS. For your infor..ation, T a copy of the staff minutes of that meeting is attached as Enclosure 1. As can be seen from the minutas, at the meeting the staff:
a) Reiterated that ATWS is still believed by the staff to be a serious safety cor.ccrr. and th:i futu:e prots: tion : hop 1d Sc prcvided. We steted that we are unwilling to wait another year to make progress on ATWS.
b) f.xpressed some general and specific technical concerns raised by the Thru. Mile Island accident with regard to the ATW5 resolution proposed in Volume 3 of NUREG-0460.
c) Asked the industry to provide in writing, within 30 days of the meeting date, its preliminary assessment of the Three Mile Island impact on ATWS, the scope of effort now foreseen to resolve TMI issues, and a realistic schedule for providing the needed ATWS infonnation. This would include both the March request and the TMI-related analyses. l 1
Subsequent to the July 25 meeting, we have met with representatives of the four NSSS vendors and of some Utility /0wners. We have met with G.E. to discuss the scope of the remaining generic analysis information to be supplied for BWR 4/5/6's.
We have also met with representatives of the GE BWR/3 Owners, B&W, B&W ATWS Owners Group, W, W ATWS Owners Group, and C.E. At all these meetings, we con-sidered further the required information and the schedule for its submittal.
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J o .I o We' have n'ow received letters (see the list in Enclosure 2, attached) from the various groups describing the infomation to bE furnished and projected schedules.
My' objective is to submit a proposed ATWS rule.to the Comission for both PWR's and BWW s early in 1980. The type and content of the rule we will propose will depenci critic 6iiy upon Inc types and u;:d=:d of the infometic . eveilable to the staff. Tnis will, of course, include whatever responses are actually provided ,
by the industry in response to the questions attached to the February 15 staff letter, the liarch meetings, and the Three Mile Island related concerns as 1
discussed in the July 25 and subsequent meetings.
'. ar fir-ly convinced that the early verification generic analysis progrc . .:=1d, if successfully carried out, provide for resolution of ATWS with the best available technical content and the least possible expenditure of resources on the part of both the NRC and industry.
I want to reiterate that the success of this program depends on the availability of the information needed. I encourage you to join or form Utility /0wners Groups, if you have not already done so, and provide the resources necessary to supply l l
the needed technical infomation pertaining to your plants, either operating or under construction.
If you have additional questions on the generic analysis early verification program discussed in this letter, please contact Mr. Ashok Thadani, (3'01)492-7341.
Sincerely, HRD, Director, NRR 90019 s
Enclosures:
- 1. NRC-Industry ATWS Meeting Sumary for July 25, 1979 -
2..