Document: NRC Regulatory Guide
Document ID: d0bc0d48-8edb-492d-b813-53be9418b4aa
Document Type: regulatory_guide
Title: Maintenance of Water Purity in Boiling Water Reactors (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740192.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.56
CFR Part: 
CFR Title: 

Content:
acity may be determined by a procedure recommended by the resin manufacturer. The total exchange capacity of the cation resin may be measured by a procedure recommended by the resin manufacturer or by paragraphs 41 through 49 of ASTM D2181-71, "Standard Methods of Test of Physical and Chemical Properties of Ion-Exchange Resins. -* For resins that are to be regenerated, these determinations should be repeated at least semiannu ally. The resins should be discarded and replaced when their capacity following regeneration falls below 60 percent of the initial value. More frequent determinations should be made at plants using seawa ter or other water containing large amounts of dis ,solved or suspended matter as coolant in their heat exchangers. For resins that are not regenerated but *Copies may be obtained from the American Society for Test ing and Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103. are instead replaced periodically with material of the same type, measurements of initial capacity should be made on a sample of new material at least once a year (when the time between replacements is less than 1 year) or at each replacement (when the time between replacements exceeds'l year). When the type of anion or cation resin is changed, a measure ment of total capacity of the replacement resin should be made prior to use in the demineralizer. 4. The licensee should verify that the minimum re sidual demineralizer capacity in the most depleted demineralizer unit established in accordance with the recommendations of regulatory position 2 is main tained. The following is an example of an acceptable method for determining the condition of the de mineralizer units so that the ion exchange resin can be replaced or regenerated before an unacceptable level of depletion is reached. a. Recording conductivity meters should be in stalled at the inlet and outlet of both the condensate treatment system and reactor water cleanup system. The range of these instruments