ML20055F134
| ML20055F134 | |
| Person / Time | |
|---|---|
| Issue date: | 05/15/1990 |
| From: | Rogers K NRC COMMISSION (OCM) |
| To: | Chilk S NRC OFFICE OF THE SECRETARY (SECY) |
| References | |
| NUDOCS 9007130331 | |
| Download: ML20055F134 (4) | |
Text
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N0TATION V 0 T.E..............
RELEASED TO THE PDR !
RESPONSE SHEET
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................e.....
TO:
SAMUEL J. CHILK, SECRETARY OF THE CO M ISSION FROM:
C0MISSIONER ROGERS
SUBJECT:
SECY-90-016 - EVOLUTIONARY LIGHT WATER REACTOR (LWR) CERTIFICATION ISSUES AND THEIR RELATIONSHIP TO CURRENT REGULATORY REQUIREMENTS APPROVED P" *"x DISAPPROVED P""w ABSTAIN m n.
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NoT PARTICIPATING REQUEST DISCUSSION COMMENTS:
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RELEASE VOTE
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ID WITHHOLD VOTE
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(N ENTERED ON "AS" YEs No
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CORRESPONDENCE PDC
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COMMENTS ON SECY-90-016 May 15, 1990 As detailed below, I approve most of the staff's recommendations in this SECY subject to no emergence of significant new considerations at the June briefing of the Commission by EPRI on l:
their Requirements-Document.
Should any such matters arise, I may decide to review my vote on this SECY.
It would seem to be prudent for the Commission to withhold its final decisions on this SECY
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until after the EPRI briefing has taken place.
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I.
General Issues
.A.
ALWR Public Safety Goal I approve of the staff's use of the quantitative safety goals (mean core damage frequency of less than 10E-5 event per reactor-year and overall mean frequency of a large release of radioactive materials from a reactor accident of less than 1 in 1,000,000 per year-of reactor operation) as expected design targets for ELWR designers, and I endorse a requirement that applicants be able to demonstrate that they have taken reasonable steps to reach those targets.
- However, I do not endorse those goals as absolute L
requirements for approval of any specific design.
l I do not accept the staff's definition of a large release in SECY-89-102.
Presumably, the Commission-will soon adopt its own definition of a large release.
B.-Source Term I endorse the staff's efforts to seek ways to decouple siting from plant design for future reactors.
I endorse the staff's interim recommendations for evolutionary ALWRs to incorporate changes to regulations as source term research l
permits and to minimize case by case exemptions.-
II. Preventative Features Issues A.
ATWS I approve the staff's latest position (which is not explicitly stated in the SECY) that diverse scram systems must be provided for evolutionary ALWRs unless the designer can demonstrate that the consequences of an ATWS are acceptable 1.e.,
the ACRS recommendation B. Mid-Loop Operation I approve a.) the staff recommendation that evolutionary PWR design vendors must propose design features to ensure high reliability of the shutdown heat removal system, and b.) the four more specific requirements proposed by the ACRS in their April 26,
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1990 letter.
C.
Station Blackout I approve the staff recommendation of a requirement for evolutionary ALWRs of an alternate ac source of diverse design capable of powering at least one complete set of normal shutdown
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D.
Fire Protection I approve the staff's recommendations for enhanced fire protection requirements and the staff's response to the ACRS recommendations regarding further enhancements as contained in the k
EDO's memorandum to the Commission of April 27, 1990.
E.
Intersystem LOCA I approve the staff's recommendations together with the ACRS recommendations with regard to all elements of the low pressure piping system.
III. Mitigative Features Issues A.
Hydrogen generation and Control I approve of the staff recommendation that the requirements of 10 CFR 50.34 (f) (2) (ix) remain unchanged for evolutionary ALWRs.
B.
Core-Concrete Interaction - Ability to Cool Core Debris I approve the general criteria stated by the staff that evolutionary ALWR designs 1) provide sufficient reactor cavity floor space to enhance debris spreading, and 2) provide for quenching debris in the reactor cavity.
C.
High Pressure Core Melt Ejection L
I approve,the staff recommendation that evolutionary ALWRs l
designs must include a depressurization system and cavity design l
features to contain core debris, but in a manner that does not interfere with essential maintenance and surveillance activities.
D. Containment Performance I approve the staff position that either a conditional containment failure probability of 0.1 or a
deterministic performance goal that offers comprabable protection must be j
demonstrated by evolutionary ALWR designs.
E. ABWR Containment Vent Design I approve the staff's use of a containment overprotection system in the ABWR design certification process, subject to the results of a regulatory review.
F.
Equipment Survivability I approve the staff's position (which has also been endorsed by the ACRS).
In this, I note the ACRS comment that the staff's position includes much more than the underlined portions of the enclosure to the SECY.
IV. Non-Severe' Accident Issues A. Operating Basis Earthquake (OBE)/ Safe Shutdown Earthquake (SSE)
I approve the staff's proposals for considering design-specific exemptions to the requirement that the OBE be at least one half the SSE, where this can be justified.
I approve the additional suggestions of the ACRS listed in their April 26, 1990 letter.
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~4 B. Inservice Testing of Pumps and Valves l
I approve the staff's provisions for inservice testing of pumps and valves'if accompanied by the four ACRS additions stated in their letter of April 26, 1990..
I am particularly concerned about an inservice full flow test provision being rigidly applied so as to include to very large pumps and valves for which such testing may not be practical.
I am however-very supportive of.the staff's initiative to require full flow inservice testing of all safety related pumps and valves.
Kek-1 i
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