ML18046A945

Notifies That Revised Evaluation for SEP Topic IV-3.A Transmitted in NRC 810826 Ltr Contained Incorrect Revised Statement Re Seiche Height.Clarification Provided.Existing Plant Design Is Conservative & Further Review Unwarranted

ML18046A945
Person / Time
Site:	Palisades
Issue date:	09/28/1981
From:	Vincent R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Crutchfield D Office of Nuclear Reactor Regulation
References
TASK-02-03.A, TASK-03-03.A, TASK-2-3.A, TASK-3-3.A, TASK-RR NUDOCS 8110010263
Download: ML18046A945 (2)

Text

consumers Power company General Offices: 212 West Michigan Avanua, Jackson, Ml 49201 * (517) 788-0550 September 28, 1981 Director, Nuclear Reactor Regulation Att Mr Dennis M Crutchfield, Chief Operating Reactors Branch No 5 US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT - SEP TOPIC III-3.A, EFFECTS OF HIGH WATER LEVEL-ON STRUCTURES; TOPIC II-3.A, HYDROLOGIC DESCRIPTION By letter dated August 26, 1981, the NRC issued a revised evaluation for SEP Topic III-3.A. It has been noted that one of the revised statements in this document is incorrect and should be clarified.

In previous correspondence regarding Topics II-3.A and II-3.B (NRC letter of March 20, 1981 and CPCo letter of August 13, 1981) it has been stated that the limiting components for site flooding are the service water pumps at elevation 594 1 -8 11

• The flood level now being discussed is up to elevation 597.1'. A detailed review has not been performed to assess the effect of a flood 2.4' higher than the limiting component, but it is clear that a number of additional components could be affected, including the auxiliary feed pumps. Therefore the statement in the second paragraph on page 2 of the staff's August 26, 1981

• letter is incorrect. The auxiliary feed pump room could be flooded by water at a 597.1 1 elevation. We believe that the intent of the statement in the SER is to say that the auxiliary feed pump room would not be affected structurally by this flood level since Topic III-3.A is a structural topic, but the statement can be interpreted much more broadly.

As discussed previously in CPCo letter of August 13, 1981, we still take strong exception to the staff value for flood level of 597.1 1

• The staff's value for seiche height of 13.6' which leads to this flood level is considered to be un-realistic and unsupported. It is interesting to note that the staff's basis for a seiche height of 13.6' was embodied in calculations performed by CERC for the NRC in a letter dated October 30, 1969. CPCo received a copy of this letter on August 17, 1981, and immediately responded with off-the-docket comments and information showing that assumptions and b~ses for the CERC value were incorrect.

• It was assumed that these comments would completely resolve the issue. It is our present understanding that this matter is not yet resolved, and is still undergoing staff review. /Jo "'3.S-1/0 8110010263 810928 \

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2 It must be pointed out that the NRC had this CERC seiche height calculation prior to initial plant licensing. The issue of seiches was addressed during Palisades licensing, both in the FSAR body and in Question 2.4 of Amendment 15 for which the latest CPCo response is dated December 5, 1969. It is apparent that the NRC rejected the CERC calculation at the time, as evidenced by the fact that the plant was found acceptable for licensing, and was licensed for full power operation in October, 1972. We know of no additional informa-tion which would invalidate the staff's earlier finding, and as discussed above, the basis for the current NRCposition,the CERC calculation, has been shown to be incorrect. We therefore submit that the existing plant design (which can withstand almost three times the realistically calculated maximum probable seiche height) is conservative, and that further review of this issue is unwarranted.

Robert A Vincent Staff Licensing Engineer CC Director, Region III, USNRC NRC Resident Inspector - Palisades