ML20077B403

Proposed Changes to Bases Section of Tech Spec 3.10 Re Core Monitoring & Spiral Unloading Program

ML20077B403
Person / Time
Site:	Pilgrim
Issue date:	05/07/1991
From:	BOSTON EDISON CO.
To:
Shared Package
ML20077B396	List: BECO-91-064, Forwards Changes to Tech Spec Bases for Section 3.10, Core Alterations Per 791121 Amend 39 to License DPR-35,in Response to NRC Concerns During 1989 Refueling of Browns Ferry.Changes Cover Spiral Reload ML20077B403
References
NUDOCS 9105140301
Download: ML20077B403 (4)

Text

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PNPS TECHN! CAL SPECIFICATIONS List of Effective Paati East Revision Amendment PJLqt Revision ILmendment List of Effective Pages: License as Amended:

LOEP-1 148 1 0 LOEP-2 146 2 0 L0EP-3 148 3 135 LOEP-4 148 4 115 LOEP-5 146 5 134 Index of Technical Specification Order dated 09/12/80 (6 pages)

Changes: Order dated 01/09/81 (6 pages)

Order dated 01/13/81 (7 pages) i 12 Order dated 04/08/81 (3 pages) 11 23 Order dated 07/10/81 (10 pages) til 37 Order dated 01/18/82 (10 pages) iv 41 Order dated 01/19/82 (5 pages) v 45 Order dated 02/16/82 (2 pages) vi 50 Order dated 03/14/83 (10 pages) vii 57 Order dated 06/24/83 (5 pages) viii 66 Order dated 09/22/83 (5 pages) ix 72 NRC Letter datad 11/08/83 (2 pages) x 80 NRC LeMer dated 03/09/84 (2 pages) xi 88 Order dated 06/15/84 (4 pages) xii 93 Order dated 07/02/84 (4 pages) xiii 103 99 Order dated 11/27/85 (3 pages) xiv 114 111 xv 123 120 Technicel Specifications Cover Page xvi 133 125 xvii 141 129 Title Page xvili 14E 135 xix 149 --- Table of Ct,ntents:

Index of Technical Specification i 148 135 Clarifications: 11 146 133 111 146 133 C-1 141 Technical Specifications:

Clarification 87-01, 09/14/87 (1 Page)

Clarification 88-01, 11/29/88 (5 Pages) 1 146 133 Clarification 88-02, 12/02/88 (2 Pages) 2 64 Clarification 89-01, 09/16/89 (2 Pages) 3 116 113 Clarification 89-02, 10/02/89 (2 Pages) 4 15 Clarification 89-03, 10/17/89 (3 Pages) 5 0 Clarification 89-04, 11/29/89 (3 Pages) Sa 138 128 Clarification 89-05, 12/13/89 (2 Pages) Sb 138 128 Clarification 90-02, 05/16/90 (2 Pages) 6 146 133 Clarification 90-03, 06/13/90 (3 Pages) 7- 146 133 8 146 133 Materials License: 9 146 133 10 146 133 1 6 2 6 Revision 149 L0EP-1 9105140301 910507 PDR ADOCK 05000293 P pop

PNPS TECHNICAL SPECIFICATIONS List of Effective Paaes (continued)

P_ Age Revision Amendment Elge Egy111gn Amendment 185 89 206f-1 117 114 186 89 206f-2 117 114 187 89 206g 117 114 188 89 206h 117 114 189 89 2061 117 114 190 89 2061-1 117 114 191 89 2063 76 192 89 206j-1 117 114 1 193 89 206k 36 193a 89 2061 36 '

193b 89 206m 146 133 193c 89 207 91 193d 89 208 145 132 193e 89 209 145 132 193f 89 210 145 132 ,

194 117 114 211 145 132 194A 61 212 145 132 195 136 -127 213 145 132 196 136 127 214 145 132 197 136 127 215 145 132 198 0 216 146 133 199 136 127 217 146- 133 200 42 217a 146 133 201 148 135 218 145 132 202 8 219 145 132 203 108 220 145 132 203a 41 221 145 132 204 0 222 145 132 204A 149 --- 229 89 205 149 --- 230 89 205a- 146- 133 231 89 205b 146 133 232 89 205c 146 133 205d 146 133 205e 146 133 205f 146 133 206 117 114 206a 117 114 206b 117 114 206c 117 114 206c-1 117 114 206d 117 114 206e 117 114 206e-1 117- 114 206e-2 117 114 206f 117 114 i Revision 149 L0EP-4

l 3.10 PASIS: i B. Core Monitorina The SRH's are provided to monitor the core during periods of station shutdown )

and to guide the operator during refueling operations and station startup. ,

Requiring two operable SRM's in or adjacent to any core quadrant where fuel or I control rods are being moved ensures adequate monitoring of that quadrant during such alterations. The requirement of 3 counts per second provides assurance that neutron flux is being monitored and ensures startup is conducted only if the source range flux level is above the minimum assumed in the control rod drop accident.

The limiting conditions for operation of the SRM subsystem of the Neutron Monitoring System are derived from the Station Nuclear Safety Operational Analysis (Appendix G) and a functional analysis of the neutron monitoring system. The specification is based on the Operational Nuclear Safety Requirements in subsection 7.5.10 of the Safety Analysis Report.

A spiral unloading program is one by which the fuel is in the outermost cells (four fuel bundles surrounding a control blade) is removed first. Unloading continuesbyremovingtheremagngoutermostfuelcellbycell. The center cell will be the last removed. A spiral loading program is one by which I fuel is loaded on the periphery of the previously loaded fueled region I beginning around a single SRH. Spiral unloading and reloading will preclude i the creation of flux traps (moderator filled cavities surrounded on all sides by fuel).

During spiral unloading, the SRM's shall have an initial count rate of 2 3 cps with all rods fully inserted. The count rate will diminish during fuel removal. Under the special condition of complete spiral core unloading, it is expected that the count rate of the SRM's will drop below 3 cps before all of the fuel is unloaded.

Since there will be no reactivity additions, a lower number of counts will not present a hazard. When all of the fuel has been removed to the spent fuel storage pool, the SRM's will no longer be required. Requiring the SRM's to be

! operational prior te fuel removal assures that the SRM's are operable and can be relied on even when the count rate may go below 3 cps.

During spiral reload, SRM operability will be verified by using a portable external source every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> until the required amount of fuel is loaded to maintain 3 cps. As an alternative to the above, up to two fuel assemblies l

will be loaded in different cells containing control blades around each SRM to obtain the required 3 cps. Until these assemblies have been loaded, the 3 cps requirement is not necessary.

l U)During selected refueling outages, prior to initiating spiral unloading, l the central controlled cell will be removed to facilitate inspection of l

the Core Spray Spargers.

l Revision 99, 149, 204A l

$.10 BAELS:

C. Spent Fuel Pool Hattr_Lettl To ensure there is adequate water to shield and cool the irradiated fuel assemblies stored in the pool, a minimum pool water level is established. The minimum water level of 33 feet is established because it would be a significant change from the normal level (-l foot) and is well above the level to assure adequate cooling.

D. Epiticle Control Rod Remqyal These specifications ensure maintenance or repair of control rods or rod drives will be performed under conditions that limit the probability of inadvertent criticality. The requirement that the fuel assemblies in the cell controlled by the control rod be removed from the reactor core before the interlock can be bypassed ensures withdrawal of another control rod does not result in inadvertent criticality. Each control rod essentially provides reactivity control for the fuel assemblies in the cell associated with the control rod. Thus, removal of an entire cell (fuel assemblies plus control rod) results in a lower reactivity potential of the core.

4.10 EASES:

A. Refuelina Intellpfki Complete functional testing of all refueling interlocks before any refueling outage will provide positive indication that the interlocks operate in the situations for which they were designed. By loading each hoist with a weight equal to the fuel assembly, positioning the refueling platform, and withdrawing control rods, the interlocks can be subjected to valid operational tests. Where redundancy is provided in the logic circuitry, tests can be performed to assure that each redundant logic element can independently perform its functions.

B. Core Monitoring Requiring the SRH's to be functionally tested prior to any core alteration ensures the SRH's will be operable at the start of that alteration. The daily response check of the SRH's ensures their continued operability.

Revision 149 205 l

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