ML092440804
| ML092440804 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 08/28/2009 |
| From: | Dean E D Constellation Energy Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-08-001 | |
| Download: ML092440804 (4) | |
Text
Calvert Cliffs Nuclear Power Plant 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 Constellation Energy Nuclear Generation Group August 28, 2009 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
SUBJECT:
Document Control Desk Calvert Cliffs Nuclear Power Plant Unit Nos. I & 2; Docket Nos. 50-317 & 50-318 Change in Alternative Course of Action Schedule Described in Our Three-Month Supplemental Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (a) NRC Generic Letter 2008-01, dated January 11, 2008, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems"
REFERENCES:
(b) Letter from Mr. J. A. Spina (CCNPP) to Document Control Desk (NRC), dated April 11, 2008, Three-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (c) Letter from Mr. J. A. Spina (CCNPP) to Document Control Desk (NRC), dated June 25, 2008, Change to Three-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (d) Letter from Mr. M. G. Kowal (NRC) to Mr. J. A. Spina (CCNPP), dated August 4, 2008, Calvert Cliffs Nuclear Power Plant Unit 2 Re: Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," Proposed Alternative Course of Action (TAC No. MD7808)(e) Letter from Mr. J. A. Spina (CCNPP) to Document Control Desk (NRC), dated October 10, 2008, Three-Month Supplemental Response to NRC Generic Letter 1008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" Reference (a) requested each licensee to provide certain information in a written response, to be submitted in accordance with 10 CFR 50.54(f), within nine months of the date of the Generic Letter (GL).Additionally, Reference (a) requested that if a licensee cannot meet the requested response date, the licensee "shall provide a response within 3 months of the date of this GL." In the three-month
- response, Document Control Desk August 28, 2009 Page 2 the licensee was requested to describe the alternative course of action that it proposes to take, including the basis for the acceptability of the proposed alternative course of action.In Reference (b), as revised in Reference (c), we provided our three-month response to the information requested in Nuclear Regulatory Commission (NRC) GL 2008-01 for Unit 2, including a description of our proposed alternative course of action. In Reference (d), the NRC staff found our proposed alternative course of action acceptable, with the exception of the clarifications and associated requests delineated in the enclosure to Reference (d). The clarifications were submitted in our three-month supplemental response (Reference e).As stated in Reference (e), we identified sections of piping for the subject systems that are located in the Unit 1 Auxiliary Building [horizontal runs of the Unit 1 safety injection discharge piping and two horizontal runs of refueling water tank (RWT) normal suction piping]. This piping was inadvertently omitted from the scope of the Unit 1 walkdowns conducted.
The required evaluations for this additional identified piping could not be complete by October 11, 2008 (nine months from the date of GL 2008-01).Our alternative course of action planned for the subject piping identified in Unit I was to defer the walkdowns and examinations until the next available on-line maintenance opportunity (no later than August 30, 2009) for the safety injection system discharge piping and the next scheduled Unit I refueling outage (Spring 2010) for the RWT normal suction piping.We are unable to complete the walkdowns and examinations for the safety injection discharge piping by August 30, 2009. This is primarily due to our decision to reschedule the walkdowns and examinations until a later date when the increased dose rates in the area, which resulted from our recent unscheduled (forced) Unit 1 outage (July 2009), have decreased.
This will minimize dose to our personnel.
Also, due to the recent Unit 1 outage (July 2009), we were able to complete the examinations of the RWT normal suction piping, that were previously scheduled for the next Unit I refueling outage (Spring 2010).Therefore, we are revising our alternative course of action for the subject piping identified in Unit 1 as follows: Our alternative course of action planned for the subject piping identified in Unit I is to defer the walkdowns and examinations until the next available on-line maintenance opportunity (no later than December 31, 2009) for the safety injection system discharge piping. A recent unscheduled (forced) Unit 1 outage (July 2009) provided access to the RWT normal suction piping.Specifically, the forced outage (July 2009) resulted in a significant decrease in dose rates in the 27' West Penetration Room allowing the examinations of the two normal suction headers from the RWT to be completed.
No air was found in either header including the local high points.As a result of the proposed change to our alternative course of action, the basis for acceptability described in Reference (e) is also revised as follows: For the Unit 1 safety injection discharge piping horizontal runs: The discharge piping designed high points (inverted loop seals) were inspected and found full.Also, points along this piping that had the potential for gas collection due to back leakage and stripping have been inspected and found full. Based on this, it is reasonable that subtle high points along horizontal runs of the same piping are also full. The December 31, 2009 completion date was established to ensure the subject activity is planned, scheduled and implemented in accordance with station procedures, commensurate with the risk significance associated with completing this task, and to allow time for the increased dose rates which resulted from a recent Unit 1 forced outage, to decrease resulting in reduced dose to our personnel.
Document Control Desk August 28, 2009 Page 3 For the Unit 1 RWT normal suction piping located in the 27' West Penetration Room: The RWT supply headers flow horizontally or down vertically to the common Emergency Core Cooling System/containment spray suction headers at the (-) 6" elevation.
There are no designed high points in these pipe runs. The portions of the missed piping in the West Penetration Room represent a small portion of the overall pipe runs. The balance of these pipe runs has been inspected and local (high points of horizontal runs) high points have been found full. Also, we have not observed issues with gas ingestion from RWT suction piping. Based on the above, it is reasonable that the subject sections of horizontal runs are also full. During power operation, the 27' West Penetration Room is a locked high radiation area. Unit 1 did not have a scheduled outage to conduct the required walkdowns within the nine month period requested in the GL. The next scheduled outage is the spring 2010 Unit 1 refueling outage. However, during a recent unscheduled (forced) Unit I outage (July 2009), dose rates in the 27' West Penetration Room were significantly reduced allowing the examinations of the subject RWT normal suction piping to be completed.
No air was found in the subject piping including the local high points.Based upon the above, we believe that completing performance of the detailed walkdowns and subsequent evaluations of those portions of piping at Units I and 2, outside the requested nine-month period, is an acceptable alternative course of action.All other information provided in Reference (e) remains unchanged.
Document Control Desk August 28, 2009 Page 4 Should you have questions regarding this matter, please contact Mr. Jay S. Gaines at (410) 495-5219.Very truly yours, Edwin D. Dean, III Manager -Operations STATE OF MARYLAND COUNTY OF CALVERT: TO WIT: I, Edwin D. Dean, III, being duly sworn, state that I am Manager -Operations, Calvert Cliffs Nuclear Power Plant, Inc. (CCNPP), and that I am duly authorized to execute and file this response on behalf of CCNPP. To the best of my knowledge and belief, the statements contained in this document are true and correct. To the extent that these statements are not based on my personal knowledge, they are based upon information provided by other CCNPP employees and/or consultants.
Such information has been reviewed in accordance with company practice and I believe it to be reliable.Subscribed and sworn before me, a Notary Public in and for the State of Maryland and County of____\___t__r ,this 8 day of 2009."t':, , -. WIlTNE.SS my Hand and Notarial Seal: My Commission Expires: EDD/ALS/bjd i,/bio Date cc: D. V. Pickett, NRC S. J. Collins, NRC Resident Inspector, NRC S. Gray, DNR