United States Nuclear Regulatory Commission - Protecting People and the Environment

Clarification of the 11 Criteria of NUREG-0737 on Postaccident Sampling System (PASS) Capability

HPPOS-011 PDR-9111210103

See the letter from S. A. Varga to J. A. Jones (Vice President, Carolina Power and Light Company) dated September 24, 1982. Enclosed with this letter were the 11 criteria contained in NUREG-0737, Item II.B.3, on PASS capability and clarification developed by the NRR staff.

These 11 criteria are briefly discussed below; however, the document must be reviewed in its entirety. The licensee must:

  1. Provide information on sampling and analytical laboratory locations and their relative elevations, distances, as well as sample handling, transport, recirculation, analytical time limits, and provisions for sampling during loss of off-site power sufficient to meet a 3-hour sampling and analysis time limit.

  2. Provide discussions of counting equipment capabilities including provisions for sample handling and background radiation reduction to personnel (ALARA); procedures relating radionuclide concentrations to reactor core damage including the monitoring for short and long lived volatile and nonvolatile radionuclides, as well as provisions for estimating core damage based on radionuclide concentrations, core temperatures and sample location; discuss the capability of obtaining a grab sample, transport and analyzing for hydrogen; discuss capabilities to sample and analyze for accident sample species; and discuss the suitability, reliability and maintenance information of selected on-line instruments.

  3. Provide system schematics and discussions that clearly demonstrate PASS, including recirculation, is possible without using isolated auxiliary systems.

  4. Discuss methodologies for measuring total dissolved gas or hydrogen and oxygen and how this information is related to reactor coolant system concentrations. In addition, if chlorides exceed 0.15 ppm, verification that dissolved oxygen is <0.1 ppm is required.

  5. BWR's located near or using sea or brackish water in heat exchangers with single barrier protection are required to analyze chloride within 24 hours. All other plants have 96 hours. Initial chloride analysis must use dilutions of <1:1000, be reported in units of ppm, and have <0.1 ppm dissolved oxygen.

  6. Provide information on predicted personnel exposures based on person-motion sampling, transport and analysis of samples.

  7. PWR's must perform boron analysis on primary coolant. BWR's must have the capability to perform boron analysis, but need not do them providing boron was not injected.

  8. Have the capability to obtain diluted and undiluted backup samples when required. If off-site laboratories will do the backup analysis, an explanation of the capability to obtain and ship one sample per week until accident conditions do not exist is needed.

  9. Discuss the predicted activity in the samples to be taken and the methods of handling / dilution used to reduce activity sufficiently for the required analysis. The predicted background radiation levels in the counting room, including the contribution from other samples, must be stated. 10. Discuss the accuracy, range, and sensitivity of the methods of analysis. These must be adequate to provide the operator sufficient and pertinent data describing the radiological and chemical status of the reactor coolant system. The recommended accuracy, sensitivity, and ranges for numerous compounds are described in this criterion.

  10. Describe provisions for purging sample lines, reducing sample line plateout, decreasing sample loss and distortion, preventing sample line blockage, sample disposal, and limiting reactor coolant loss from ruptured sample lines. The ventilated exhaust from the sampling station must be filtered with charcoal absorbers and HEPA filters, however, the ventilation system need not be dedicated.

  11. Describe provisions for purging sample lines, reducing sample line plateout, decreasing sample loss and distortion, preventing sample line blockage, sample disposal, and limiting reactor coolant loss from ruptured sample lines. The ventilated exhaust from the sampling station must be filtered with charcoal absorbers and HEPA filters, however, the ventilation system need not be dedicated.

Regulatory references: NUREG-0737, Technical Specifications

Subject codes: 5.0, 7.6, 8.3, 10.1, 12.16

Applicability: Reactors

Page Last Reviewed/Updated Thursday, June 04, 2015