ML20004C668
| ML20004C668 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 05/28/1981 |
| From: | Steptoe P CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.), ISHAM, LINCOLN & BEALE |
| To: | BIER, MILLS, CHRISTA-MARIA, ET AL |
| Shared Package | |
| ML20004C664 | List: |
| References | |
| ISSUANCES-OLA, NUDOCS 8106040442 | |
| Download: ML20004C668 (8) | |
Text
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O 5/28/81 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Mattet of
)
)
CONSUMERS POWER COMPANY
)
Docket No. 50-155 - OLA
)
(Big Rock Point Nuclear Power Plant))
ANSWERS OF CONSUMERS POWER COMPANY TO INTERROGATORIES PROPOUNDED BY CHRISTA-MARIA, ET AL.
Pursuant to 1C CFR S2.740b, Consumers Power Company
(" Licensee") hereby submits answers to Interrogatories 4-1, 7-2(b), 8-8(a) and R-8 (b) propounded by Christa-Maria.
Interrogatory 4-1 The original spent fuel design was based on the assumption i
that spent fuel assemblies would periodically be shipped off-site for reprocessing.
a.
What was the bacis for the original design capacity of 193 fuel assemblies?
A.
Answer As indicated in the response to Interrogatory 3-4, and the documents attached thereto, the original design capacity was 120 spent fuel assemblies and not 193.
While it is not clear what the basis was for this original capacity, the 120 fuel storage locations would provide sufficient capacity for a full-core discharge plus a normal reload discharge with some additional storage 8106 0 40 Nk
U space left over for margin.
After refueling, the spent fuel was intended to be stored for at least 90 days prior to shipment off-site for reprocessing; therefore, fuel storage capacity sufficient to provide for full core discharge plus a normal refueling discharge (typically one-fourth of a full core) would make sense from an operational viewpoint.
B.
Documents Relied Upon See documents previously provided in Licensee's response to Interrogatory 3-4.
C.
Documents Reviewed But Mot Relied Upon None D.
Further Activities None Interrogatory 4-lb How do the calculations establishing the alleged safety of the 193 fuel assemblies differ from those used to justify the increase to 441 fuel assemblies?
A.
Answer i
Since the Big Rock Point Plant was a turnkey project Licensee was not provided with the calculations relating to the original spent fuel storage racks, and subsequent efforts to retrieve these calculations from Bechtel Corp.
have not proven successful.
Therefore, Licensee has j
i -
sg
.a not performed a comparison between the original calculations and calculations performed by NUS Corp. for the new spent fuel racks.
B.
Documents Relied Upon None C.
Documents Reviewed But Not Relied Upon None D.
Further Activities None Interrogatory 4-lc What are the existing inside dimensions of the spent fuel pool?
Have they changed since the Big Rock spent fuel storage pool was first installed?
If so, how, when, and why?
A.
Answer The existing inside dimensions of the spent fuel pool are approximately 20' x 26' x 30' deep.
These dimensions have changed only slightly as a result of the installation of the pool liner as discussed in 1
Licensee's response.to Interrogatory 3-5.
The width and length have each been reduced by approximately an inch and the depth reduced by approximately 6 inches due j
l to the installation of the liner. 4 e
e.
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B.
Documents Relied Upon
'None C.
Documents Reviewed But Not Relied Upon None D.
Further Activities None Interrogatory 4-ld Has the slope of the spent fuel storage pool changed since it was installed?
If so, how, when, and why?
A.
Answer The slope of the spent fuel storage pool has not changed since completion of plant construction.
B.
Documents Relied Upon None C.
Documents Reviewed But Not Relied Upon None D.
Further Activities None Interrogatory 7-2b Is the history of circuitry failures at Big Rock consistent with Rasmussen's postulations concerning the probability of such failures?
Please explain..
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-JL Answer.
i Licensee has not. performed any analyses or studios that provide a direct comparison of circuitry _ failures at Big Rock Point Plant with the assumptions used in the Reactor Safety Study (WASH-1400), sometimes referred to as the~"Rasmussen Study."
However,-the Big Rock Point l
Probabclistic Risk Assessment does provide a-comparison of Big Rock Point component failure rates with failure t
rates given in various generic studies, including t
WASH-1400.
These component failure rates reflect all l
failure's including failures of electrien1 circuitry.
I As stated in volume 1, p. 39 of the " Big Rock Point
_Frobabalistic Risk Assessment," generally, it was found that the estimates bas 2d on plant specific data gave' l
higher failure-rates 'chan generic estimates.
t B.
Documents Relied Upon Big Rock Point Plant Probabalistic Risk Assessment Vol. 1 and Appendix III.
i C.
Documents Reviewed But Not Relied Upon None I
D.
Further Activities j
None i
Interrogatory 8-8a f
i What equipment must be accessible in the containment to l
facilitate operation of the spent fuel pool?
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u en A.
Answer operation of the spent fuel pool is facilitated by accessibility of all the related equipment.
Outage of any of this equipment normally does not present any safety problem since the most significant requirement for safety is that the fuel remain covered witn water.
Under certain highly unlikely reactor accident scenarios, the ability to operate or repair spent-fuel-pool-related equipment may be temporarily impaired.
To provide additional assurance that the spent fuel will remain covered with water even under this highly unlikely scenario, modifications are being made as described in Licensee's responses to Interrogatories 8-10 and 8-11 to provide the capability to add makeup water to the spent fuel pool without entering containment.
B.
Documents Relied Upc l
None C.
Documents Reviewed But Net Relied Upon 1.
Licensee Internal Correspondence R.
E. Schrader to AIR A-NA-79-90, dated December 1, 1979 (copy provided).
2.
BRP Control Room Log Sheet (copy provided).
3.
Safety Evaluation by the Office of Nuclear Reactor Regulation relating to the Modification of the j'
1
r e
Spent Fuel Storage Pool Facility Operating License.
No. DPR 6, Consumers Power Company Big Rock Point Plant Docket No. 50-155 (May 15, 1981) (copy provided by NRC).
I D.
Further Activities Set Part A above.
Interrogatory 8-8b What equipment must be operated manually?
A.,
_ Answer All spent-fuel-pool-related equipment is operated manually.
The spent fuel pool cooling pumps'and the_
spent fuel pool makeup water modification described in Licensee's responses to Interrogatories 8-10 and 8-11 can be remote-manually actuatec
- rom outside containment.
i The rest of the spent fuel pool equipment is manually
[
actuated or operated within containment.
B.
Documents Relied Upon
[
None I
C.
Documents Reviewed But Not Relied Upon t
t 1.
Licensee Drawing 0740G40lli, Rev. V, 2.
BRP Surveillance Test T90-08 (copy provided).
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D.
Further Activities See responses to Interrogatories 8-10 and 8-11.
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or'/Ihilip P. Steptoe pne of the Attorneys for Consumers Power Company ISHAM, LINCOLN & BEALE Suite 4200 One First National Plaza Chicago, Illinois 60603 312/558-7500 f
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