ML20217M253
| ML20217M253 | |
| Person / Time | |
|---|---|
| Site: | University of Michigan |
| Issue date: | 04/02/1998 |
| From: | Fleming R MICHIGAN, UNIV. OF, ANN ARBOR, MI |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20217M258 | List: |
| References | |
| NUDOCS 9804080051 | |
| Download: ML20217M253 (3) | |
Text
1 The University of Michigin
. Michigan M:mori .1 Phoenix Prsject Office of the Director l 2301 Bonisteel Boulevard Ann Arbor, Michigan 48109-2100 April 2,1998 Docket 50-2 ;
License R-28 i United States Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555 Re: Ford Nuclear Reactor License and Technical Spaifications, 1 Amendment 44: Forced Convection hilet Temperature LSSS and Reactor Coolant Temperature LSSS l
The University of Michigan hereby submits Amendment 44 to the Ford Nuclear Reactor Technical Specifications.
The changes are explained below. Enclosed is a copy of the revised pages with the l changes underlined and denoted in the right margin. )
On March 25,1998 the FNR experienced a failure of the primary coolant pump. The safety ;
system (High Power /No Flow scram) operated as intended and the reactor was safely shut !
down. A spare pump is available on site. After performing a Pan 50.59 review for !
- *allation of the spare pump an apparent Unresolved Safety Question as defined in Part
_0.59(a)(2)(iii) may exist. We have ceased operation of the reactor in forced convection cooling mode until this issue is resolved.
The issue involves using Reactor Coolant Outlet Temperature as the LSSS channel to )
protect against exceeding the Safety Limit on Reactor Coolant Inlet Temperature. The !
current Reactor Coolant Outlet Temperature LSSS of 129oF (which includes a 2oF margin for measurement error) is based on the 15oF AT that would exist across the core at the Safety Limit coolant inlet temperature of 1160F and Safety Limit coolant flow rate of 900 gpm while operating at 2 Mw thermal power .
The Safety Analysis Report shows that increasing flow above 900 gpm increases core cooling. Improving the cooling gives a larger margin of protection against the fuel cladding reaching the boiling point of the water coolant, provided the Safety Limit on the inlet temperature of 1160F is satisfied. And, boiling is the event these Safety Limits are intended to protect against.
However, forced convection operation at any flow rate above the Safety Limit value of 900 gpm causes a decrease in the margin between the coolant temperature LSSS and Safety Limit because increasing the flow rate decreases the AT at 2 Mw. The LSSS on coolant exit temperature becomes ineffective at preventing the 2 Mw coolant inlet temperature Safety Limit of 116oF from being exceeded.
This' amendment incorporates into the Technical Specifications a safety channel on reactor coolant inlet temperature that was installed to address this problem on September 30,1997.
The LSSS causes an auto mndown at an indicated core inlet temperature of 114oF when the, n,q \ I l 9804080051 980402 ~
ADOCK 05000002 C 'l O PDR l P PDR
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, reactor is operated in forced convection mode at thermal power levels greater than 1.6 Mw as indicated on the Log N - Period Safety Channel. This safety channel provides automatic protective action to prevent exceeding the 2 Mw reactor coolant irdet temperature Safety Limit of 116oF under all anticipated normal and adverse reactor c,pera ing conditions.
Additional minor corrections have also been made to the Technical Specifications.
The following is a brief description of the specific changes: I Page 2 of License R Condition C. (2).
This change identifies Amendment 44 as the current Technical Specification revision.
j Page 7 of the Technical Specifications.
Condition 2.2.1 Applicability, Reactor Coolant Inlet Temperature Identified
]
Page 8 of the Technical Specifications. ;
New condition 2.2.1.2 adds the inlet temperature LSSS at 114oF for thermal power leve' greater than 1.6 Mw.
Page 13 of Technical Specifications. Table 3.1 REQUIRED SAFETY CHANNELS Function of the Log N Period Channel is modified to indicate that safety related ,
power level interlocks are derived from this channel. '
Reactor Coolant Inlet Temperature Channel is added which initiates an auto rundown at i14oF for power leveis above 1.6 Mw.
Reactor Pool Temperature Channel is added to specifically identify the Safety Channel that is required for the reactor poollemperature during Natural Convection Flow Mode. This Safety Channel initiates an Auto Rundown at pool temperatures greater than 129oF when the reactor is operated in natural circulation cooling mode.
Page 17 of the Tecimical Specifications, Section 3.2 Reactor Safety System Bases.
Changed to identify the purpose of the Coolant Inlet Temperature and Reactor Pool Temperature Auto Rundowns.
Changed to correctly identify the Pool Level Auto Rundown Cha- as providing automatic protection against low pool level rather than operator acu 2.
Sincerely, Ronald F. Fleming, Director Michigan Memorial- Phoenix Project cc: Theodore Michaels, USNRC Project Manager Thomas Burdick, USNRC Region III r
l
f* :
pERATING LICENSE AND TECHNICAL SPECIFICATIONS
- Ford Nuclear Reactor Docket 50-2. License R-28 Amendment 44: proposed
! C. This license shall be deemed to contain and is subject to the conditions specified in parts 20, 30, 50, 51, o5, 70, i 1
and 73 of 10 CFR Chapter I, to all applienble provisions of the Act, and to the rules, regulations _and orders of the l
mmission now or hereafter in effect and to the additional
.anditions-specified below:
i l (1) Steady State and Maximum power Levels l
l39 l
l The licensee is authorized to operate the facility at l a steady state power level of 2.0 megawatts (thermal).
l The maximum power level shall not be in excess of 2.2
! megawatts (thermal).
(2) Technical Specifications The Technical Specifications contained in Appendix A, as-revised through Amendment No. 44, are hereby.
- l44 incorporated in the license. The Iicensee shall operate the facility in accordance with the technical specifications.
(3) physical Securit,y plan The licensee shall fully implement and maintain in.
l37 effect all' provisions of the physical security plan approved L by the Commission and all amendments and changes made pursuant to the authority of 10 CFR 50.90 and 10 CFR 50.54(p), respectively. The approved plan, which is exempt from public disclosure pursuant to the provisions of 10 CFR
- 2. 790( d )( 1 ) , is entitled " Ford Nuclear Reactor Security plan," Revision 1, submitted by letter dated May 17, 1991, and supplemented February 17, 1992.
D. This license is effective as of the date of issuance and shall expire twenty years-from its date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Director j Division of Licensing Date of Issuance: July 29, 1985
Enclosure:
Appendix A, Technical Specifications L