ML20045E835
| ML20045E835 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/28/1980 |
| From: | Fitzgerald J NRC OFFICE OF THE GENERAL COUNSEL (OGC) |
| To: | |
| Shared Package | |
| ML20038A409 | List:
|
| References | |
| FOIA-92-436 SECY-A-80-062, SECY-A-80-62, NUDOCS 9307060117 | |
| Download: ML20045E835 (7) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION 4
WASHINGTON, D. C. 20555 April 28, 1980 SECY-A-80-62 COMMISSIONER ACTION-For:
The Commissioners From:
James A. Fitzgerald Assistant General Counsel
Subject:
COMMISSION REVIEW OF ALAB-589 (VIRGINIA ELECTRIC AND POWER COMPANY)
Facilities:
North Anna Nuclear Power Station, Units 1 and 2.
Purpose:
To inform the Commission of an Appeal Board C # c-decision /which, in my opinion, Discussion:
ALAB-589 is an interim decision in which the Appeal Board found that the hazard posed by turbine missiles pending the next inspection at North Anna is..not sufficient to halt opera-
--' ~. tion 'bf.Ubit fl oF to withhold the license for g l Unit'2:
Without ruling on the long-term signi-p l ficance of-turbine disk cracking, the Appeal E
Board held that because the development of 3y l turbine cracks is time-related, any cracks are t
@Z l unlikely to approach critical size before
!$l December, 1980.
Unit 1 is scheduled for refuel-I 94 !
ing at that time and VEPCO has committed itself rE to a turbine inspection.
The Appeal Board 0 I; '.
expects the results of that inspection to yield
- 12 information upon which to base new judgments DI about the continued safe operation of the two 5jm
.E 6 0 }
units.
Since Unit 2 had not yet been licensed gM at the time ALAB-589 was issued, the Board believed that it should have a final decision sBN
~on the turbine missile matter before disk EMMa
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cracking would become a significant safety hazard there. 1/
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A low power license was issued for Unit 2 on April 11, 1980.
It does not appear, however, that the issuance of the low-power license would alter the Appeal Board's judgment as it based on the limited number of hours of operation prio n December outage.
9307060117 930317 PDR FOIA 7k /]
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Regarding the Applicant's commitment'to inspec-ting the turbine in_ December, the Appeal Board-mandated that any proposed deviation from that commitment be immediately reported'to it.
In..
addition, the Appeal Board tentatively concluded that'the previously scheduled oral hearing in this proceeding was no longer necessary-in i
light of the written testimony submitted.
~
[Easedontherecord'beforeus,
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Recommendation:
'[
ey y
%..' (
. J mes A. F tzgerald
(
ssistant General Counsel
Attachment:
ALAB-589 Comissioners' comments should be provided directly to the Office of the Secretary by '
c.o.b. C.,,.J L C, 1980.
- -I a n =>uu; w-'
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pw,f4 rioy l -
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Comission Staff Office coments, if any, should 'be sub' itted to the Comissioners 'NLT!
m May 6 1980, with an information copy to the 0ffice of the Secretary.
If the paper isl of such a nature that it requires additional time for analytical review and coment, the Comissioners and the Secretariat should be apprised of when coments may bei expected.
DISTRIBtlTION
~~
Comissione s Comission Staff Offices
I Cs 6'
UNITED STATES'OF AMERICA i
NUCLEAR REGULATORY COMMISSION g
e s
b hi ATOMIC SAFETY AND LICENSING APPF_AL BOARD T
e Alan S.
Rosenthal, Chairman
- &\\g Dr. John H. Buck 4 l 3 Michael C. Farrar 3ERVEC
,ACR 1l
)
In the Matter of
)
)
VIRGINIA ELECTRIC AND POWER COMPANY). Docket Nos. 50-338 OL
)
50-339 OL
'i (North Anna Nuclear Power Station
)
Units 1 and 2)
)
)
MEMORANDUM AND ORDER April 7, 1980 (ALAB-589)
~
During tihe course 'of our Teview cf-the; Licensing. Board's P " i 1/
decision in this operating license proceeding,~ we raised two safety issues on our own initiative.
See ALAB-491, 8 NRC 245 (1978).
Last June, we conducted an evidentiary hearing on both issues.
We disposed of one of them earlier this_ year by deciding that the continuing settlement of the ground be-neath the service water pumphouse did not pose an unmanageable problem.
ALAB-578, 11 NRC _ (February 11, 1980).
h 1/
That Board had found' no barrie' 'to the award of operating.
licenses for both units.
The Unit 1 full-power license
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was issued on April 1, 1978 and commercial' operation of that unit began on June 6,1978.
No license.for Unit 2 has yet been issued.
- 2. -
At that time, we reserved decision on the other plant safety issue, that relating to turbine missiles (i.e.,
to the likelihood that pieces of the turbine would break off and cause unacceptable damage -- in terms of safety conse-quences -- to other plant systems).
We held up our decision because new developments bearing on the resolution of the turbine misaile question had been brought to our attention.
Specifically, cracking of turbine disks had been uncovered at a number of facilities employing equipment made by the same 2/
manufacturer that supplied the North Anna turbines.~~
We tentatively scheduled a supplemental hearing to con-sider that new information.
See our unpublished memorandum of February 12, 1980.
The applicant requested, however, that before we went ahead with the hearing, we first consider wh ther
~
our concerns might be satisfied by certain information it 3/
would f urnish us in writing.-
Upon reviewing that material together with the NRC staff's appraisal of the matter, a majority of this Board made three determinations which were embodied in an unpublished order issued on March 3, 1980.
First, the submissions went "a long way toward establishing that operation of North Anna 1 need not be halted now in order to conduct a lengthy inspection of its turbine".
- Second, 2/
Additionally, we were advised that the manufacturer was re-analyzing the potential amount of energy associated with the missiles created by turbine disk disintegration.
3/
Otherwise, that information would have formed the foundation for testimony at the hearing.
e
. 4' there consequently was no need to proceed with the hearing (at least as it was then scheduled).
Third, the applicant and the staff should be called upon to explain further (again in writing) the underpinnings of certain analyses 4/
employed by them in arriving at their conclusions.-~
We now have that further explanation before us.
It furnishes necessary support for the conclusions previously advanced.
On the basis of it, we are able to determine that the turbine disk cracking being experienced elsewhere is not likely to occur to any hazardous extent at North Anna Unit 1 prior to the next refueling shutdown, now scheduled for December of this year.
That is because the development of the cracking phenomenon is time-related; in light of the number of hours the Unit 1 turbine will have been in opera-tien, we can say with reasonable assurance on the basis of the record now before us (reflecting experience elsewhere) that any cracks that might develop would nor have had time 5/
to approach critical size by then.-~ The applicant has made a commitment to have the turbine inspected during the December i
4/
Dr. Buck dissented from so much of the March 3 order as
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sought this additional information.
In his view, not s
shared by the majority, the information already supplied was sufficient to permit continued operation of Unit 1
)
until the next scheduled shutdown (see pp. 3-4, infra).
_5/
As noted above, Unit 2 has not yet begun operation.
Our f2nal decision on the turbine missile cuestion should thus be rendered long before disk cracking might become a problem for that unit.
8 1
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a F
6/
shutdown;-
that inspection will be capable of detecting any substantial cracking that may actually have occurred.
And the results of the inspection will furnish a foundation for new judgments about the safety of any operations beyond th.at point.
For now, the recent developments relating to the turbine missile problem do not -require either that opera-tion of Unit 1 be halted or that Unit 2 be kept out of opera-tion.
This is not to say, however, that we now have the final word on the long-term significance of the disk cracking pheno-i menon.
For example, we do not know the extent of its impact on the continuing validity of certain portions of the evidence that was adduced before us at the hearing last year, which dealt with the turbine missile question in terms of the plant's full lifetime.
Indeed, it will be some time before the extent 7/
of that impact will be known.-
Of at least equal importance, there is nothing now before us which might explain the basic reasons for the surprisingly early crack formation in turbine blades of the same type and manufacture as tho,se used in the North Anna units.
We will expect the papers supplied to us 6/
See "VEPCO's Responses to Site Specific General Questions on * *
- Unit 1",
Nos.
I.B, II and IV.
Needless-to say, any proposed deviation from that commitment must be immediately reported to us.
7/
- The applicant's present estimate is that it will be this October before it will be able to advise us finally either on that score or with regard to the results of the reanal-ysis which is being done on the subject of missile energy (see fn.
2,, supra).
-*rr, r-W 1a r r -
4
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later this year to address in some detail what has been ascer-tained regarding the causes of the early cracking, as well as the steps being taken to correct the problem.
In the circumstances, we will continue to defer our de-8/
cision on the turbine missile question.-
Implicit, of course, in our taking such a step is our tentative conclusion, based on our study of the record thus far, that the safety concerns that motivated us to call the hearing in the first place were otherwise adequately addressed in the testimony.
Final decision deferred.
It is so ORDERED.
FOR THE APPEAL BOARD 0.
h C. Jeph Bishop
\\
SecretMry to the Appeal Board 8/
It remains to be seen whether a supplemental hearing will be needed before we reach that decision.
.