ML13151A047

Response to Request for Additional Information Regarding Calculated Peak Containment Internal Pressure License Amendment

ML13151A047
Person / Time
Site:	Calvert Cliffs
Issue date:	05/28/2013
From:	George Gellrich Calvert Cliffs, EDF Group, Constellation Energy Nuclear Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML13151A047 (6)

Text

George H. Gellrich Vice President Calvert Cliffs Nuclear Power Plant, LLC 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410.495.5200 410.495.3500 Fax CENG a joint venture of cmaelatlon

'-'eDF Energy0 CALVERT CLIFFS NUCLEAR POWER PLANT May 28, 2013 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:

Document Control Desk

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit Nos. I and 2; Docket Nos. 50-317 and 50-318 Response to Request for Additional Information Containment Internal Pressure License Amendment Regarding Calculated Peak

REFERENCES:

(a)

Letter from Mr. C. R. Costanzo (CCNPP) to Document Control Desk (NRC), dated July 2, 2012, License Amendment Request:

Revise Calculated Peak Containment Internal Pressure (b)

Letter from Ms. N. S. Morgan (NRC) to Mr. G. H. Gellrich (CCNPP),

dated April 25, 2013, Request for Additional Information Regarding Calculated Peak Containment Internal Pressure License Amendment (TAC Nos. ME9081 and ME9082)

In Reference (a), Calvert Cliffs Nuclear Power Plant, LLC submitted a license amendment request to revise the calculated peak containment internal pressure described in Technical Specification 5.5.16 and the initial internal containment pressure limit in Technical Specification 3.6.4. In Reference (b), the Nuclear Regulatory Commission requested additional information to support their review of Reference (a). Attachment (1) provides the responses to the Nuclear Regulatory Commission's request for additional information contained in Reference (b).

These responses do not change the No Significant Hazards Determination provided in Reference (a). No regulatory commitments are contained in this letter.

Document Control Desk May 28, 2013 Page 2 Should you have questions regarding this matter, please contact Mr. Douglas E. Lauver at (410) 495-5219.

I declare under penalty of perjury that the foregoing is true and correct. Executed on May 28, 2013.

Very truly yours, George H. Gellrich Vice President GHG/PSF/bjd

Attachment:

(1)

Response to Request for Additional Information Regarding Calculated Peak Containment Internal Pressure License Amendment cc:

N. S. Morgan, NRC W. M. Dean, NRC Resident Inspector, NRC S. Gray, DNR

ATTACHMENT (1)

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING CALCULATED PEAK CONTAINMENT INTERNAL PRESSURE LICENSE AMENDMENT Calvert Cliffs Nuclear Power Plant, LLC May 28, 2013

ATTACHMENT (1)

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING CALCUALTED PEAK CONTAINMENT INTERNAL PRESSURE LICENSE AMENDMENT

RAI 1

In regard to your response to the NRC staff's request for additional information question number 5 in letter dated February 6, 2013, (ADAMS Accession No. ML13036A237), provide justification on how equipment qualification (EQ) remains bounded for all points of the figures provided in Attachment I of your March 6, 2013, letter. Also, explain how margins are being maintained for equipment required to meet Title 10 of the Code of Federal Regulations section 50.49.

CCNPP Response 1:

Part (1) - Provide justification on how equipment qualification remains bounded for all points of the figures provided in Attachment 1 of the March 6, 2013.

The Figure 1 below is a revised version of Figure 1 in Reference 1.

300 280 260 240 6220-I E

120 IO0 0.01 0.1 1

10 100 1000 10000 100000 1000000 10000000 Time (led Figure 1 - Comparison of Containment Temperature with Environmental Qualification Temperature Profile The dotted EQ bounding temperature profile is taken from the Calvert Cliffs Engineering Standard (ES-014) and is used for environmental qualification of plant equipment. In Figure 1 above, the starting point for the EQ bounding temperature profile was corrected to match the starting point for the plant's new temperature profiles CCXVAP and CCIVAP for a cold leg break loss-of-coolant accident. When comparing the plant and EQ bounding temperature profiles of Figure 1, one can see that the EQ bounding temperature profile envelopes the plant temperature profiles. Therefore, there is no impact on the existing Calvert Cliffs EQ program, and the EQ program remains in compliance with 10 CFR 50.49.

1

ATTACHMENT (1)

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING CALCUALTED PEAK CONTAINMENT INTERNAL PRESSURE LICENSE AMENDMENT The Figure 2 below is a revised version of Figure 2 in Reference 1.

65 60 55

'U 45 S3S 0.

ED 25 4

20 11-02 21,-01 11+i00 L-E+01 11+02 11E03 11+04 11E+05 11+06 rime (sec)

Figure 2 - Comparison of Containment Pressure with Environmental Pressure Profile Qualification The EQ bounding pressure profile (ES-014) is taken from the Calvert Cliffs Engineering Standard (ES-014) and is used for environmental qualification of plant equipment. Comparing the plant and EQ bounding pressure profiles of Figure 2 shows that EQ bounding pressure profile does not envelope the plant pressure profiles for 14 seconds (from 6-20 seconds). However, the EQ bounding pressure profile bounds the plant pressure profiles in both magnitude (65 psia versus 62 psia) and duration (2+ hours versus 14 seconds).

This small difference in the initial portion of the plant profile is considered insignificant.

Therefore, it is concluded that the EQ bounding pressure profile envelopes the plant pressure profiles. Therefore, there is no impact on the existing Calvert Cliffs EQ program and the EQ program remains in compliance with 10 CFR 50.49.

Part (2) - Explain how margins are being maintained for equipment required to meet 10 CFR 50.49.

Temperature and pressure margins in the Calvert Cliffs EQ program are applied in accordance with 10 CFR 50.49 and Regulatory Guide 1.89. These margins are applied in addition to the EQ bounding (ES-014) temperature and pressure profiles for equipment qualified to 10 CFR 50.49. This combination of EQ bounding profiles plus temperature and pressure margins are bounded by the Calvert Cliffs EQ equipment test profiles, which are tested to harsher environmental conditions. Therefore, there is no impact on the existing Calvert Cliffs EQ program.

2

ATTACHMENT (1)

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING CALCUALTED PEAK CONTAINMENT INTERNAL PRESSURE LICENSE AMENDMENT

RAI 2

Provide a discussion on any impact of the proposed change on areas of the plant outside of containment (e.g., changes to EQparameters such as temperature and pressure).

CCNPP Response 2:

The proposed change in calculated peak containment internal pressure for the design basis loss-of-coolant accident does not result in any impact on any area of the plant outside of the Containment. As a result, environmental conditions outside of the Containment remain bounded by existing site calculations.

REFERENCE:

1.

Letter from G. H. Gellrich (CCNPP) to Document Control Desk (NRC), dated March 6, 2013, Response to Request for Additional Information Regarding Calculated Peak Containment Internal Pressure License Amendment 3