ML20202E205
| ML20202E205 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 02/03/1998 |
| From: | Hammer M NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 50-263-94-08, 50-263-94-8, NUDOCS 9802180094 | |
| Download: ML20202E205 (3) | |
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,o Northem States Power Company Monteeno Nuclear oenerating Plant 2807 West Hwy 76 MonticeHo. Minnesota $$3624637 February 3,1998 US Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 MONTICELLO NUCLEAR GENERATING PLANT Docket No. 50 263 License No. DPR 22 Supplemental Response to Provide the Results of NSP's inquiry into the Intent of OM-1. Section 4.3 of Section XI of the ASME Boiler and Pressure Vessel Code Ref.1) Letter from W.J. Hill, NSP, to US Nuclear Regulatory Commission, ' Response to Unresolved items Contained In inspection Report 50 263/94008," November 28, 1994
Background
By letter dated November 28,1994 (Rof.1), NSP provided a response to Unresolved item (URI) 940081. This item concerns the cold setting of certain relief valves in the MNGP Inservice Testing Program. By this letter, NSP also committed to provide the results of a related inquiry by NSP to the OM 1 code committee to clarify the intent of OM 1, Section 4.3. The results of this inquiry and NSP's resolution of this item are provided herein.
Relief Valves Tht. subject relief valves are all part of the RHR system and are categorized in their design specification as thermal relief valves. The valves are exposed to a range of operating pressures and temperatures including normal system (liquid) temperatures.
OM 1-1981 paragraph 4.1.3.1, Test Media, states: " Valves shallbe tested with the vormal system operating fluid and temperature for which they are designed. Alternative liquids or different temperatures may be used, provided the requirements of 4.3 are met."
In regard to the unresolved item, NSP's pcsition was that these valves are being tested at a temperature for which they are designed when they are tested at their cold set pressure (cold differential test pressure). The typicalinformation supplied to a relief valve manufacturer when a new relief valve is ordered includes set pressure and maximum inlet temperature. The manufacturer supplies the valve set on the bench at
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required set pressure and maximum inlet temperature. The cold set pressure value is stamped on the valve nameplate. Since the manufacturer uses the maximum inlet ten 1peratute and set pressure as inputs to determine the cold set pressure, it is considered a design value. Bench testing at the cold set pressure is then in accordance with the first sentence of paragraph 4.1.3.1 Code Committoo inquity The following questions were submitted by NSP for initial code committee review on December 9,1994 in accordance with our response to the URI.
Question: Does performing a cold setpoint bench test on a Class 2 liquid relief valve, where the cold setpoint is provided by the manufacturer, test the valve as it is designed such that paragraph 4.3 and subparagraphs 4.3.1,4.3.2, and 4.3.3 do not apply?
Proposed Reply: Yes Question: If the answer to the above question is no, can a safety evaluation performed by the utility satisfy the intent of these code requirements.
Proposed Reply: Yes Codo Commilloo Responso The following questions and answers were received by NSP from the OM code committee on November 11,1997 in response to that inquiry.
Cuestion(1): Are the requirements of ANSI /ASME OM Part 1 paragraph 4.3 [ASME Code Appendix l paragraph l 4.3), Alternate Test Media, met if the cold differential test pressure as marked on the nameplate as provided by the manufacturer is used as an attemate test pressure as permitted by paragraphs 4.1.2.1 and 4.1.3.1 [ paragraphs 1 4.1.2(a) and I 4.3(a)) and provided no other qualification exists?
Reply (1): No.
Question (2): Are the requirements of ANSI /ASME OM Part 1 paragraph 4.3 [ASME OM Code Appendix l paragraph I 4.3), Alternate Test Media, met if the documentation required by pragraph 4.3.2 [ paragraph I 4.3.2) and the written procedure required by paragraph 4.3.3 [ paragraph I 4.3.3) are prepared by the valve manufacturer and accepted / certified by the Owner?
Reply (2): Yes.
Conclusion NSP's originalinquiry was asking for confirmation that testing at the cold set pressure complied with the first sentence of paragraph 4.1.3.1. It is our conclusion that the revised inquiry and its response does not answer that question. We s'.ill believe our initial response to the unresolved item, which is contained in Ref.1, is correct and that we are in compliance with the code.
Given the time delay for the first response from the code committee, it is NSP's position that there is not much value in further pursuing the original code inquiry. Since NSP believes that additional test data to document the lift characteristics of these valves over a range of liquid and ambient temperatures is warranted, Condition Report 97002860 has been initiated to track this item. Actions taken to resolve this condition report will envelope the concerns raised in the Unresolved Item 94008-1.
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A The testing involved to obtain the desired data, including setpoint checks at liquid temperatures above 212 'F. is unique. An off site vendat capable of performing the 1
desired testing on safety related, contaminated valves has recently been identified. One relief valve representative of the subject relief valves is curtsntly availaole for testing, j
j NSP anticipates that this testing can be completed and the results obtained by the end of the 1998 refueling outage, currently scheduled for completion on April 23,1998. Test a
results will be incorporated into Condition Report 97002860 to ottermine if further l
actions are required.
This letter contains no new licensing commitments.
Please contact Joel Borea, Monticello Licensing, at (612) 2951436 if you require i
additionalInformation.
$4K14%
Michael F. Hammer Plant Manager Monticello Nuclear Generating Plant
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Regional Administrator Ill, NRC NRR Project Manager, NRC Sr. Resident inspector, NRC State of Minnesota, Attn: Kris Sanda J. Silberg, Esq.
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