ML100690276

E-mail from R.Guzman to T.Darling Request for Additional Information - Containment & Ventilation Branch - Extended Power Uprate

ML100690276
Person / Time
Site:	Nine Mile Point
Issue date:	03/10/2010
From:	Richard Guzman Division of Operating Reactor Licensing
To:	Nine Mile Point
Guzman R, NRR/DORL, 415-1030
References
TAC ME1476
Download: ML100690276 (2)

Text

From: Guzman, Richard Sent: Wednesday, March 10, 2010 12:12 PM To: Darling, Theresa H Cc: Dosa, John J

Subject:

Containment & Ventilation Additional RAIs

Theresa, As we discussed by teleconference on March 3, 2010, the NRC staff of the Containment &

Ventilation Branch had a follow-up question to the Nine Mile Point Nuclear Station, LLC (NMPNS, or the licensee) RAI response (letter dated December 23, 2009) to NRC question RAI-F1. Additionally, the NRC staff requested additional information regarding residual heat removal (RHR) heat exchanger performance. Both questions, shown below, are needed to complete the NRC staff's review.

As we discussed, please provide your docketed supplemental response by April 17, 2010.

Please contact me, if you have any questions.

Thanks, Rich Guzman Sr. Project Manager NRR/DORL US NRC 301-415-1030 Richard.Guzman@nrc.gov Containment & Ventilation RAI-F-1A:

Provide the peak containment pressures and peak containment temperatures resulting from EPU with a main steam line break in containment upstream of the main steam line flow restrictor.

For RAI F1, issued by NRC letter dated November 13, 2009, the NRC staff requested clarification, or to reference, previously submitted documentation that justifies why the EPU does not increase the amount of energy released from a steam line break upstream of the main steam line flow restrictor. The licensee's response was that the initial conditions (steam dome pressure and steam quality) are not changed. The licensee also referenced NEDC-33351P Rev. 0 Section 2.2.1 as providing documentation of the confirmation performed for NMP2 EPU.

The NRC staff notes the following items in support of clarifying RAI F1:

- NEDC-33351P, Section 2.2.1 addresses pipe rupture locations and dynamic effects of pipe ruptures. Since there is no change to the pressure and steam, quality the specific, energy of the steam remains unchanged.

- A steam line break upstream of the flow restrictor cannot be isolated. The higher reactor EPU power levels could lead to more total energy released.

- NEDC-33004P, Section 4.1. Containment System Performance, states the effect of the CPPU on containment systems will be analyzed for each plant using the methods documented in Section of Reference 1 (NEDC-32424P). The assessment will include pressure and temperature response.

- NEDC-32424P only states the EPU application will show acceptability of the effect on the uprated power on containment capability. The evaluations will include containment pressures and temperatures. The staff is not able to find any reference that the analysis is limited to a recirculation suction line break.

- NMP2 USAR Section 6.2 states [t]o ensure that the primary containment system design parameters are not exceeded for pipe breaks smaller than the DER of the largest primary system pipe, a spectrum of break sizes is analyzed. Among the breaks considered is an instantaneous guillotine DER of a main steam line.

RAI-F-12:

Table 2.6-3 of NEDC-33351 provides RHR heat exchanger performance values used in the EPU analyses. These values (K-value of 265 BTU/sec-°F for EPU DBLOCA) are higher than the actual heat exchanger performance with service water at 82°F (K-factor of 239 BTU/sec- °F as discussed in NMP2 USAR, Section 6.2).

1. Provide a justification for using a heat exchanger performance value for the analyses that is greater the actual performance value.

2. Provide a justification why the RHR heat exchanger total fouling resistance used for the EPU analysis (0.001344 hr-ft²-°F/BTU/HX for DBLOCA) is less than discussed in the NMP2 USAR (0.001 hr-°F-ft²/BTU for tube side fouling and 0.0005 hr-°F-ft²/BTU for shell side fouling).

3. Discuss the program NMP2 uses to assure the RHR heat exchangers perform at a level to assure the minimum performance values used in the EPU analyses are maintained. Include the margin MNP2 uses to account for instrumentation accuracy, low heat exchanger loads, and service water temperatures lower than the EPU analyses basis.

E-mail Properties Mail Envelope Properties (92E0E77F3622DA40B501E8D45083D5D9508499C167)

Subject:

Containment & Ventilation Additional RAIs Sent Date: 03/10/2010 12:11:33 PM Received Date: 03/10/2010 12:11:00 PM From: Guzman, Richard

Created By: Richard.Guzman@nrc.gov Recipients:

Theresa.Darling@cengllc.com (Darling, Theresa H)

Tracking Status: None John.Dosa@cengllc.com (Dosa, John J)

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Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: