ML20245E098
| ML20245E098 | |
| Person / Time | |
|---|---|
| Issue date: | 12/09/1988 |
| From: | Gillespie F Office of Nuclear Reactor Regulation |
| To: | Houston R NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML20245E100 | List: |
| References | |
| NUDOCS 8812160006 | |
| Download: ML20245E098 (4) | |
Text
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d ENCLOSURE ?
je UNITED STATES y
p, NUCLEAR REGULATORY COMMISSION e t WASHINGTON,0, C. 20566
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4 December 9, 1988-hEMORANDUM FOR:
R. Wayne Houston Division of Reactor Accident Analysis Office of Nuclear Regulatory Research FROM:
Frank P. Gillespie, Director Program Management, Policy Development and Analysis Staff Office of Nuclear Reactor Regulation
SUBJECT:
CONCURRENCE ON CRGR PACKAGE FOR MARK I CONTAINMENT PERFORMANCE IMPROVEMENT PROGRAft The subject package was concurred in by E. Beckjord on November 23, 1988 and delivered to NRR for concurrence. We have concurred in the package going forward for CRGR review, but as we discussed with Bill Beckner are submitting several comments which we believe deserve careful consideration prior to the paper going beyond CRGR approval. The coments are enclosed.
rank P. Gil p
Director Program Management, Policy Development and Analysis Staff Office of Nuclear Reactor Regulation
Enclosure:
As stated cc:
A. Thadant C. Thomas W. Beckner O
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12/09/88 Enclosure NRR Comments on the Mark I Containment Performance Improvement Procram -
Submittal for CR6R Review 1.
Numerical values resulting from PRA analyses and subseciuent cost / benefit analysis, which are used to support recommendations and conclusions, should be critically reviewed to assure the highest reasonable confidence in values used as calculated.
2.
Page 6, Commission paper, first complete sentence: "Other changes, such as raising the vent valve operability pressure and/or raising the RCIC turbine back pressure trip setpoint, may also be desirable." This implied requirement, unlike other plant capabilities discussed in this part of the paper, is not disposed of later on in the paper, begging the question of what further, if anything, is intended by the staff. This matter should be clarified.
3.
Page 11, of the Commission paper, second paragraph, indicates that the costs of enhancement are estimated to be from 1.6 to 3.1 million dollars per plant, even though actual experience with similar improvements at the one plant which has made these changes cost about 7.3 million dollars. The paragraph should provide a more convincing rationale for why NRC is justified in assuming much lower costs than experienced.
4.
Page 20 of Enclosure 4 Regulatory Analysis describes the impact of this paper on Improved Plant Operation (IPO) initiatives. The last sentence (on page 21) indicates that the improved procedures and cperator training part of IPO is related to the CPI program's recommended tons, but does not say how. The current regulatory initiatives for Rev. 4 EPGs should be discussed.
5.
Persons not familiar with the overall severe accident program may question the emphasis on Mark I containments. A statement should be included early in the Commission paper reminding readers that Mark II and III and other containment types are the subject of parallel but separate program efforts, in accordance with the Integration Plan for closure of Severe Accident Issues SECY-88-147, 6.
The paper, particularly at page 5 last paragraph, does not clearly indicate how or why proposed Mark I venting would " greatly" reduce the calculated core melt frequency. An explicit mechanistic description should be included somewhere; we suggest this is an appropriate location.
7.
Page 25, Enclosure 4 Regulatory Analysis, last para melt frequency can be reduced from between 1.6 (10)gaph, "... totgl core to9.7(10)~ per reactor
- year. " This expression needs rewording for clarity.
It is not 1
clear whether the words refer to a difference or to an absolute value of l
core melt frequency.
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UNITED STATES f
g NUCLEAR REGULATORY COMMISSION 7,,
E WASHINGTON, D. C. 20555
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JAN 3 1937
,i 99 iz MEMORANDUM FOR:
Victor Stello, Jr.
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Executive Director for Operations FROM:
James H. Sniezek, Chairman Comittee to Review Generic Requirements
SUBJECT:
MINUTES OF CRGP MEETING NUMBER 104 The Comittee to Review Generic Requirements (CRGR) met on Ponday, December 22, 1986, from 9 a.m. to 12 N.
A list of attendees for this meeting is enclosed (Enclosure 1).
P. Pernero INRR) presented a CRGR brieOng regarding the proposed Generic 1.etter concerning improvements to PWR Mark I Containments. Although originally scheduled for CRGR review, Mr. Bernero indicated that since NRR and OGC concur-rences on the package had not yet been obtained, the CRGR should consider the meeting as a briefing. Once the appropriate concurrences are obtained, Mr. Bernero intends to submit the package for CRGR review. This matter is discussed in Enclosure 2. contains predecisional information and, therefore, will not be released to the Public Document Room until the NRC has considered (in a public forum) or decided the matter addressed by the information.
Questions concerning these meeting minutes should be referred to Walt Schwink i492-8639).
0 wil>e(,
L mes H. Sniezek, Cha rman omittee to Review Generic Requirements
Enclosures:
As stated cc.: Comission (5)
SECY Office Directors Regional Administrators CRGR Members W. Parler
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Enciosure 2 to the Minutes of CRGP Meetina No.104
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Review of the Propo,ed Generic Letter Recardina BWP Mark I Containment R. Bernero (NRR) presented the proposed Generic Letter (GL) regarding 3WR Park I "ontainment modifications.
R. Bernero began the presentation by providing a brief history from the time of the TMI-2 accident (1979) to the present. The vuaraphs used for this pre-sentation are attached (Attachment 1). The discussion was extensive and informative, and for the most part the vugraphs were self-explanatory.
The primary objective of the GL is to implement a set of generic Mark I con-tainment requirements now rather than to await completion of the independent plant evaluations (IPEs) being performed in consonance with the 1985 Severe Accident Policy.
In fact, if the generic changes are made, the need for this-portion of IPEs will be eliminated for this class of plants.
There are many salient issues identified in the CRGR sumary and issue identifi-cation (Attachment 2). During the meeting, the need to address these issues was recognized.
The CRGR specifically suggested that the following issues be addressed:
(1)
Independent Plant Evaluations (IPEs) are presently being performed in consonance with the Severe Accident Policy.
The tie in with the imple-mentation of this policy needs to be more fully addressed.
(2) The Safety Goal Policy was approved by the Commission in 1986. At present, the staff is beginning its implementation of venting requirements. These proposed requirements should be assessed in light of NUREG-1150 results and the Safety Goal Policy.
(3) Achieving a 10-6 probability of a significant release is the objective of the GL. The GL achieves this by mitigative modifications.
Preventive measures should also be considered and the rationale for the appropriate s tradeoff explained.
(4) Containment performance objectives are due in April 1987. These objec-tives should be addressed to ensure a generally consistent approach l
between the GL and the iminent containment performance objectives.
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(5) The elimination of IPEs regarding containment would result in a loss of insights to be gained from these evaluations. The loss of these insights I
should be considered.
If these insights are felt to have significant value, licensees should comply with the GL and still perfonn IPEs in the containment area.
(6) Because the dominant core-melt scenario is station blackout, the proposed modifications may satisfy the Blackout Rule. The effect o# the GL on the L
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Station Blackout Rule should be addressed. Likewise, implementation of the Blackout Rule may obviate the need for containment modifications.
Again, the appropriate balance between prevention and mitigation needs to be examined.
(7) The proposed modifications may increase risk in design areas other than those directly affected. The potentially competing risks associated with the proposed modifications should be addressed.
(8) The proposed package is silent with respect to any need.for notification of the public prior to venting.
Notification of the public prior to venting should be addressed.
(9)
In today's budgetary environment, NRC resources are limited. Therefore, establishing a high priority on Mark I BWRs may cause a reduced effort on other designs such as ice containments. This should be discussed and evaluated.
(10) The Backfit Rule requires a systematic evaluation to establish that there will be a substantial increase in public health and safety. This require-ment should be more thoroughly addressed.
(11) There may be other ways to achieve BWR containment improvements that aie legally and administrative 1y more desirable. Alternatives to a GL, such as rulemaking should be evaluated.
(12) There have been significant past improvements to BWR Mark I containment i
design. Additional improvements are now being proposed. The potential i
for future additional requirements should be addressed.
f (13) The NUMARC report is due in April 1987. The value of proceeding in parallel with NUMARC rather than awaiting the NUMARC proposal should be addressed.
(14) There is little value associated with venting beyond 4 miles, in this perspective, intentional venting to reduce public exposure should be addressed, especially in light of evacuation and sheltering alternatives.
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