ML20101D154
| ML20101D154 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 06/04/1992 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9206120020 | |
| Download: ML20101D154 (3) | |
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BALTI MORE' GAS AND ELECTRIC 1650 CALVERT CtSFS PARKWAY + LUSBY, MARYLAND 20657 4702 4
ocoRor C CREEL VICE PMSIDENT NUCLE AR ENEROY (4to) 200-448S June 4,1992 U, S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Planned Technical Specification Revisions REFERENCdS:
(a)
L.etter from Mr. S. A. Toelle (ABB/CE) to Mr. R. C. Jones (NRC),
dated February 28,1992, Accuracy of Fuel Storage Rack Criticality Calculations, (b)
Letter from Mr. S. A. Toelle (ABB/CE) to Mr. L I. Kopp (NRC),
dated March 27. 1992, Accuracy of Fuel Storage Rack Criticality Calculations Gentlemen:
Baltimore Gas and Electric Company (BG&E) wishes to inform you of our plans to revise three Technical Specifications for Calvert Cliffs Nuclear Power Plant Units 1 and 2 (DPR-53 and DPR-69). In the first case, we were informed of an error in Spent Fuel Pool reactivity calculations which necessitated a change. In the other cases, internal revien identified cases where auditionalTechnical Specification controls appear to be warranted. In all three cases, administrative controls are currently in place to ensure sufficiently conservative operating conditions are maintained.
1.-
In References (a) and (b), ABB/ Combustion Engineering informed the Commission of errors in the spent fuel pool criticality calculations performed for several power plants including Calvert Cliffs. Baltimore Gas and Electric Company had used these incorrect calculations to support a request to change Technicai Specification 5.6.1 to increase the maximum allowed enrichment of fuel in the spent fuel pool to 5 weight percent (w/o) on June 9,1988 (as supplemented). The request was approved as Amendments 139 (Unit 1) and 122 (Unit 2) on January 10,1990. Uptm discovery of the error, a preliminary analysis was performed for. the Calvert Cliffs spent fuel pools which determined that the maximum allowable enrichment for 6y the Unit 1 pool is 4.55 w/o and 4.15 w/o for the Unit 2 pool. Initial results from a more
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detailed analysis indicated that a final maximum allowable enrichment for the Unit 2 poolwill be at least 4.37 w/o. The latest fuel batch loaded into the Unit 2 core is 4.3 w/o and the latest D, d
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9206120020 920604 V
PDR ADOCK 05000317 P
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i Document Control Desk j
June 4,1992 1
Page 2 batch received into the Unit 1 spent fuel pool is 4.2 w/o. All other fuel in use or in storage is less than 4.15 w/o. Therefore, we are confident that the 0.95 Ak/k Criticality requirement [Or the spent fuel pools has not been violated. We have instituted administrative controls to enforce the maximum enrichment limits on each pool as determined by the preliminary analysis.
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1 Following completion of the criticality analyses, we will request a license amendment to revise the maximum allowable enrichment for fuel in the spent fuel pools. We expect to submit the license amendment request in July 1992.
2.
During our self-assessment of electrical distribution design, we reviewed the design for the E acrgency Diesel Generator (EDG) fuel oil system. Calvert Cliffs has two Fuel Oil Storage Tanks (FOSTs), a-bunkered (i.e., tornado protected) tank and a non-bunkered tank.
i However, the technical specifications for these tanks do not reficct the design assumption that the non-bunkered tank may fait during a tornado. In that event the bunkered tank must contain a sufficient volume of fuel oil to run two diesel generators (one per unit) for seven days, per IEEE-308 and ANSI 59.52. We intend to submit a request for license amendment to change Technical Specifications 3.8.1.1.b.2 and 3.8.1.2.b.2 to increase the required volume in the bunkered tank to encompass the tornado event. This new limit is i
currently implemented by administrative controls. Revised technical specifications are under development, and we plan to request a license amendment to reflect these new analyses in July 1992.
I 3.
Technical Specification 3.8.2.1 lists the A.C. electrical busses that must be operable in Modes 1 through 4. It includes the following:
480-volt _ Emergency Bus No. I1 A or 14B 4SP-volt Emergency Bus No.14A or llB A review of the original (custom format) Unit 1 technical specifications revealed that the original requirement was that all four 480-volt emergency buses (11 A,11_B,14A,14B) be
- operable. An Action statement allowed the alternate bus arrangement in our current technical specifications for a maximum of eight hours.
When the Unit 1 technical specifications were converted to standard format in February 1977, th_e alternate bus arrangement was incorporated as the limiting condition for operation. No basis for this decision was documented. We believe a more restrictive Limiting Condition for Operation requiring availability of all four buses is more appropriate.
Nevertheless, it has been our practice to maintain all four 480-volt buses operable and energized in Modes I through 4 and to enter the Action statements for any supported safety systems when a bus was declared inoperable. We have implemented administrative controls which require entering the Action statement of Technical Specification 3.8.2.1 if a 480-volt emergency bus is inoperable. We plan to request a license amendment reflecting this requirement in July 1992.
In all three cases, BG&E has implemented administrative c<mtrols to ensure operation of the plant in a safe manner. Resolution of thcae discrepancies by license amendment will be forthcoming.
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- Document Control Desk June 4,1992 -
Page 3 Should you have any further questions regard!n; this m;tter, we will be pleased to discuss them with you.
Very truly yours.
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GCC/BDM/bdm/ dim
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D. A Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC D. G. Mcdonald, Jr., NRC J
- T. T. Martin, NRC -
P. R. Wilson, NRC R. I. McLean, DNR J. II. Walter, PSC I'
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