A Spiral load is a method of putting fuel back in the reactor vessel during a refuel outage without all control rods being inserted.
When fuel is loaded into the core with multiple control rods withdrawn, special spiral reload sequences are used to ensure that reactivity additions are minimized. Spiral reloading encompasses reloading a cell (four fuel locations immediately adjacent to a control rod) on the edge of a continuous fueled region (the cell can be loaded in any sequence). Otherwise, all control rods must be fully inserted before loading fuel. For an unloaded core the spiral reload may commence at either the core center around a "dunking type detector" or, around one of the source range monitors. Placement of the "dunking type detector" in the core cell does not violate the intent of the spiral reload pattern. Fuel assemblies may be loaded into this location when the "dunking type detector" is removed.
There are normally 4 SRMs, one in each quadrant.
Why is this needed
In a BWR control rods can not be inserted without the fuel bundles to support it because they are libel to fall over. Since not all control rods are not fully inserted the spiral pattern was developed to build the core.
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ML23173A040 | 10 April 2023 | Peach Bottom | 9 to Updated Final Safety Analysis Report, Chapter 7, Control and Instrumentation - Redacted | ML23095A374 | 5 April 2023 | FitzPatrick | Enclosure 2: Technical Specification (TS) Bases Revision 58 | ML23095A376 | 5 April 2023 | FitzPatrick | Enclosure 4: Technical Requirements Manual (TRM) Revision 109 | LR-N23-0024, Submittal of Hope Creek Generating Station Technical Specification Bases Changes | 29 March 2023 | Hope Creek | Submittal of Hope Creek Generating Station Technical Specification Bases Changes | ML23062A427 | 3 March 2023 | Peach Bottom | 8 to Updated Final Safety Analysis Report, Chapter 7, Sections 1 Through 9 (Redacted) | ML22292A119 | 5 October 2022 | Nine Mile Point | Rev. 48 to Technical Requirements Manual | ML22292A125 | 5 October 2022 | Nine Mile Point | 5 to Updated Final Safety Analysis Report, Chapter 15, Appendices | JAFP-21-0022, Technical Requirements Manual Specifications - Redacted | 29 March 2022 | FitzPatrick | Technical Requirements Manual Specifications - Redacted | ML22012A435 | 14 February 2022 | Salem Hope Creek | and Salem Nuclear Generating Station, Unit Nos. 1 and 2 - Issuance of Amendments Nos. 230, 342, and 323 Delete Definition in 10 CFR 20 and Figures of Site and Surrounding Areas | LR-N21-0079, Submittal of Hope Creek Generating Station Technical Specification Bases Changes | 3 November 2021 | Hope Creek | Submittal of Hope Creek Generating Station Technical Specification Bases Changes |
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