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09/21/2006 Summary of Meeting with Omaha Public Power District (OPPD) to Discuss OPPD Participation in the Water Management Strategies Program
	ML062700644
Person / Time
Site:	Fort Calhoun
Issue date:	10/20/2006
From:	Wang A; NRC/NRR/ADRO/DORL/LPLIV
To:	;
	Wang A, NRR/DORL/LP4, 415-1445
References
	TAC MC5780
	Download: ML062700644 (5)
	v • d • e

October 20, 2006LICENSEE:Omaha Public Power DistrictFACILITY:Fort Calhoun Station, Unit No. 1

SUBJECT:

SUMMARY

OF SEPTEMBER 21, 2006, MEETING WITH OMAHA PUBLIC POWER DISTRICT (OPPD) (TAC NO. MC5780)

On September 21, 2006, the U.S. Nuclear Regulatory Commission (NRC) staff conducted a meeting with OPPD to discuss its participati on in the Water Management Strategies program.

OPPD had recently requested, and the NRC staff had approved, an extension to the completion

date of the Generic Safety Issue (GSI)-191 efforts. OPPD stated it will complete the actions

stated in its request for the fall 2006 refueling outage. However, as the result of some of the

chemical effects testing, OPPD is concerned as to whether it will be able to complete the

analysis to finalize the final resolution of GSI-191 by the extension date. OPPD is looking at

different water management strategies that would allow them to meet its commitment for

completion of the GSI-191 effort by April 2008.

OPPD is evaluating two possible water management strategies to limit the load on the strainers:

(1) OPPD would change the start logic on the containment spray pumps (CSPs) to start on high

containment pressure and low steam generator pressure and (2) OPPD would terminate CSPs

at the start of recirculation. In both cases, OPPD proposes to provide core cooling using the

high-presure safety injection pump(s) for recircul ation. OPPD provided some preliminary results of the transport analysis assuming these water management strategies. The NRC noted that

the transport fraction of low density fibers went from 100 percent to 0 percent. OPPD stated this

was a result of the transport analysis for these scenarios. The NRC staff agreed the transport

would be reduced but felt 0 percent was probably not a realistic number. OPPD agreed but

again noted this was a calculated number and that the real number is somewhere between 0

percent and 100 percent. The NRC staff noted that other transport assumptions noted in the

OPPD slides were also beyond those approved in the industry guidance report. The NRC staff

did note that such a plant-specific approach was allowed but would require specific NRC review

and approval.

OPPD provided some discussion on regulatory obstacles. In particular, OPPD discussed the possible effects on the dose consequences and the maximum containment pressure and

temperature calculations due to the stoppage of containment spray. Alion provided a closed

discussion on a proposed new method to estimate aerosol natural deposition inside the

containment as related to the dose calculations. As an alternative, OPPD noted it is pursuing

qualifying the containment recirculation system high efficiency particulate air (HEPA) filters to be

able to apply credit in the dose calculations for mitigation of the radioactivity release inside the

containment. OPPD stated that the preliminary results for not starting the CSPs during a

loss-of-coolant accident are that the containment design pressure and temperature would not

be exceeded. OPPD stated that if the containm ent recirculation system HEPA filters can be qualified, it believes the calculated doses will be within regulatory limits. The NRC staff noted

that if OPPD wants to qualify the HEPA filters in an expeditious manner, it should not deviate

from the American Society for Testing and Materials requirements. OPPD stated that its goal is to complete the GSI-191 effort by April 2008. However, if it pursues one of the above strategies, OPPD would like to know if the NRC would consider an extension

should the ramifications of the water management review result in a need to go beyond April

2008. OPPD notes that the water management strategies would possibly provide them the

margin that would allow the use of a smaller strainer than the currently proposed strainer of

3,000 square feet. OPPD stated that it would like to pursue this option and has not started the

scheduling pending the result of this meeting. OPPD noted that it understands that because of

some of its unique design features, its water management strategies may not apply broadly to

the industry. The NRC staff agreed but felt several of the OPPD issues are applicable to other

plants seeking to do water management strategies. The NRC staff noted that while OPPD's

approach appears to be reasonable, OPPD is proposing something quite complex and different

from the rest of the industry. As such, the NRC staff will need to discuss it further internally.

The NRC staff stated it would keep OPPD informed of its discussions.

A list of attendees is enclosed. The OPPD and Alion non-proprietary presentation slides are available in the Agencywide Document s Access and Management System (ADAMS) under accession numbers ML062680528 and ML062700272, respectively.

The NRC staff thanked OPPD for the presentation.

Please direct any inquiries to me at 301-415-1445, or abw@nrc.gov

./RA/Alan B. Wang, Project Manager Plant Licensing Branch IV

Division of Operating Reactor Licensing

Office of Nuclear Reactor Regulation Docket No. 50-285

Enclosure:

List of Meeting Attendees

cc w/encl: See next page OPPD stated that its goal is to complete the GSI-191 effort by April 2008. However, if it pursues one of the above strategies, OPPD would like to know if the NRC would consider an extension