ML17266A376
| ML17266A376 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 11/10/1980 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Ahearne J NRC COMMISSION (OCM) |
| Shared Package | |
| ML17209A468 | List: |
| References | |
| REF-GTECI-A-44, REF-GTECI-EL, TASK-A-44, TASK-OR ALAB-603, TAC-43912, NUDOCS 8012230040 | |
| Download: ML17266A376 (2) | |
Text
UMITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O. C. 20555 gory 1 0 >980 Yi"-IORANDUYIFOR:
Chairman Ahearne FROYa'HRU:
Harold R. Denton, Director Office of Nuclear Reactor Regulation William J. Dircks.
Executi ve Direct,or for Operations SUMECT:
STATION BLACKOUT
.'n our rI morandum dated September 26, 1980, we presented the A-44 Task Action Plan or station blackout (loss of all AC power events) and indicated that i~lcm ntation of the ALAS-603 recoIIrii ndations was being evaluated in response
.to your inquiry of August 20, 1980.
The purpose of this memorandum is to describe the action plan which we believe will resolve the Board s concern and to re'spond to your s'ubsequent follow-up questions of October.24, 1980.
The Atomic Safety and Licensing Appeal Board (ALAB-603) concluded that station blackout should be considered a design basis event for St. Lucie Unit 2 and recomII nded that, in view of the completion schedule for Task A-44, "for nuclear power facilities with a station blackout likelihood corparable to that oi St. Lucie Unit 2, expeditious measures be taken to ensure that these plants and their operators are equipped to accomnodate such an event in a manner that assures the public health-and safety."
Our.initial response to the Board's decision was to am nd the construction permit. for St. Lucie Unit 2 (September
'8, 1980) to require that station blackout be included as a design basis
'vent, as was ordered by the Board.
~ A aimUar~equirem nt. has been imposed on St. Lucie Unit 1; iInder the provisions of 10 CFR 3'art 50.54 (f), in order o provide consistency-.in<he design basis for-4he sister-plant.
As descri bed in the attached 'meneraiidum from~&erner o-date&A~ust<4,.-
1980 (Enclosure 1), the probability of station blackout is not significantly
'ia fferent between St. Luci e and all other nu cl ear power plants-This asser-tion is based on the preliminary staff study mentioned~-Sec~ian-3.of TAP A-44.
All plants.
including St Luci.e, are cosparable in statio~lactout-probability within the uncertainty band.
Me are currently updatiTIg<hat study with improved data and more careful docum ntation of the assumptions and limitations-Section 3 of TAP A-44 provides the basis for continued plan licensing and operation.
The preliminary probabilistic study provides supplem ntary information to the Bulletins and Orders~equimnmnts wi~d-in- -
that section,'hich were the principal bases for continued operation.
The,-
extent to which station blackout should be considered in the design of all o.her plants, and the criteria by which it should be considered, will be es.ablished by Task>-44..
Me have reviewed the schedule for Task A-44 and conclude that it cannot be significantly.iaqroved.
Nevertheless,'e.
concur..
with.he Board's reconm ndation that soIn interim measures should be taken while Task A-44 is being conducted.
Contac:
C. Grim s, DOL X28204 8 0X8 8 Q 0~dIdg
~
~
Chairrian Ahearne Consequently, we plan to issue the enclosed generic letter (Enclosure g),
which requires that all licensees and applicants develop interim emery(icy procedures and a training program for station blackout events-We believe
'hat this action will resolve the Board's concern for the period while Task A-44 is being conducted.
In addition, there are som short-term system improvements associated with other actions'which will reduce the potential for and consequences of a station blackout event.
These are:
1-The short-term improvements to the auxiliary feedwater system in PWR plants associated with Task II.E.l.l of the TMI-2 Action Plan (NUREG-0660)-
These improvements are scheduled to be coaqleted by July 1, 1981.
2.
The installation of quencher safety-relief valve discharge devices in BMR plants associated with the Mark I Containment Long Term Program.
The schedules for the Nark I-related plant modifications are described in SECY-80-359 and SECY-80-359A-A 3-The recomnendations for improvements to the emergency diesel gen-erators which have evolved from a recent contractor study of diesel reliability (NUREG/CR-0660)-
These recomnendations are currently being implemented on OL license applications and'a program for implementation for the operating reactors, including improvements to the related Technical Specifications, is being developed We believe that the development of emergency procedures and training programs, as described in the enclosed generic letter, coupled with the stated basis for continued plant operation.cfescribed in the A-44 Task Action Plan, are suffic-ient to resolve-the'Board's concern relative to the ability.of the eperating --
plants to accommodate a-station blackout event.
Harold R. Denton, Director Office of Nuclear React'or%egulation Encl osures:
1'emorandum from R.
M. Bernero to H-R. Denton dated August 22,- j980;
- 2. Stati on Black out Generi c L,etter cc:
Comtnssioner Gi'iinsky Comttissioner Hendrie Comnissioner Bradford
'GC OPE SECY