ML20247C785
| ML20247C785 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/01/1989 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8909140108 | |
| Download: ML20247C785 (2) | |
Text
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D EALTIM ORE GAS AND CHARLES CENTER.P. O. BOX 1476 BALTIMORE, MARYLAND 21203 GEORGE C. CREEL Vict ParsIDENT NucLtan ENERGY (3o0 eco-44ss September 1,1989 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 Control Room Dose
REFERENCE:
(a) Letter from Mr.
J.
A. Tiernan (BG&E) to M r.
A.
C. Thadani (NRC), dated March 5,1986, Control Room Dose Gentlemen:
We wish to report that we have recalculated our Control Room Dose for a Loss of Coolant Accident. There are two reasons why we felt we should do so:
1.
Recent Local leak rate testing has determined that our sum of Control Room in-leakage sources has increased 180 cubic feet per minute (cfm) from the 1213 cfm used in our last calculation. The total in-leakage is now 1393 cfm.
2.
Our Technical Specifications call for a removal efficiency for radioactive methyl iodine of a 90%, but our previous dose calculations have assumed 95%. We were questioned by the NRC staff during a past Control Room Habitability review about this inconsistency and we committed to changing the Technical Specifications to 95%. Ilowever, we now feel that a recalculation of the Control Room dose using a 90% efficiency is a preferred alte. ;ative to a Technical Specification change.
All assumptions and the calculational model are the same as in Reference (a), except that the source term was based on guidance in Standard Review Plan 6.5.2 Revision 2, which references Regulatory Guide 1.4 Revision 2 June 1974, Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss of Coolant Accident for Pressurized Water Reactors.
fD0 8909140108 890901 PDR ADOCK 05900317 g (
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7 Document Control Desk September 1,1989 Page 2 The results are as follows:
Skin Dose (Rem)
Whole Body (Rem)
Calculated 18.7 1.11 Criteria per 30 5
GDC 19 l
We feel that this recalculation accurately reflects the accident dose, based on the measured in-leakage, and resolves the inconsistency with the Technical Specifications regarding Control Room Charcoal Adsorber efficiencies.
Should you have any further questions regarding this matter, we will t pleased to discuss them with you.
Very truly yours, GCC/DLS/ dim cc:
D. A. Brune, Esquire J. E.
Silberg, Esquire R. A.Capra, NRC S. A. McNeil, NRC W. T. Russell, NRC V. L. Pritchett, NRC T. Magette, DNR